News Items Archive
Please note that, for some of the older entries, links may no longer be functional.
Comparison of assay methods for cyanobacterial toxins
Australian workers compared several assays
available for the detection of cyanobacterial toxins and their producers in environmental samples:- microscopy (for identification and enumeration of cyanobacteria), ELISA (Enzyme-Linked ImmunoSorbant Assay), PPIA (Protein phosphatase inhibition assay), PSI (Protein synthesis inhibition), chemical analysis and PCR (Polymerase Chain Reaction). Results showed that there was generally a good correlation between the presence of potentially toxigenic cyanobacteria and the detection of the toxin by ELISA. However oncentrations of saxitoxins quantified by ELISA were significantly different than those measured by LC-MS. Data suggest that cell numbers and toxin concentrations measured in bioassays do not necessarily correlate and that enumeration of potentially toxic cyanobacteria by microscopy, while commonly used for monitoring and risk assessment, is not the best indicator of real toxin exposure.
Graphene sieve could make seawater safe to drink
Manchester researchers have developed a method of making graphene-oxide membranes capable of sieving common salts, a development which has the potential to provide clean drinking water for millions of people who struggle to access adequate clean water sources. The membranes can achieve 97% rejection for NaCl. The atomic scale tunability of the pore size also opens new opportunity to fabricate membranes with on-demand filtration capable of filtering out ions according to their sizes . (See abstracts 1
Neonicotinoid Insecticides in Drinking Water and Fate during Drinking Water Treatment
Concern over the use of neonicotinoid pesticides is growing as studies find them in rivers and streams, and link them with declining bee populations and health effects in other animals. US researchers report
that in some areas, drinking water also contains the substances. Although GAC treatment removed clothianidin, imidacloprid and thiamethoxam, a rapid sand filtration system alone reduced the same substances only by about 1 percent, 8 percent and 44 percent, respectively.
Efficacy of membrane filtration processes to remove human enteric viruses and the suitability of surrogates for those viruses.
Japanese workers evaluated the efficacy
of direct microfiltration (MF) and ultrafiltration (UF) to remove three representative human enteric viruses (i.e., adenovirus [AdV] type 40, coxsackievirus [CV] B5, and hepatitis A virus [HAV] IB), and one surrogate of human caliciviruses (i.e., murine norovirus [MNV] type 1. They compared the removal ratios of two bacteriophages (MS2 and φX174) and a plant virus (pepper mild mottle virus; PMMoV) with the removal ratios of the human enteric viruses. PMMoV appears to be a suitable surrogate for human enteric viruses, whereas MS2 and φX174 do not, for the assessment of the efficacy of membrane filtration processes to remove viruses.
Passive membrane systems for drinking water treatment
The widespread adoption of submerged hollow fibre ultrafiltration (UF) for drinking water treatment is currently hindered by the complexity and cost of these membrane systems, especially in small/remote communities. Most of the complexity is associated with auxiliary fouling control measures. A recent study
investigated the contribution of different auxiliary fouling control measures to the permeability that can be sustained, with the intent of minimizing the mechanical and operational complexity of submerged hollow fiber UF membrane systems while maximizing their throughput capacity. Sustained conditions could be achieved without backwashing, air sparging or chemical cleaning ( passive operation) but the permeability that could be sustained was only approximately 20% of that which can be maintained with fouling control measures.
Retaining a small amount of air sparging (i.e. a few minutes daily) and incorporating a daily 1-h relaxation (i.e. permeate flux interruption) period prior to sparging more than doubled the permeability that could be sustained . The high throughput capacity that can be sustained by eliminating all but a couple of simple fouling control measures make passive membrane systems ideally suited to provide high quality water especially where access to financial resources, technical expertise and/or electrical power is limited. (Press Release
Potential impacts of changing supply-water quality on drinking water distribution
A recent review concludes that irregular changes of water quality
may cause destabilization of pipe material and contaminants and the potential transition effects can lead to health or esthetic issues. A framework is proposed for the evaluation of potential transition effects.
Impact of recycling filter backwash water in water treatment
A study by chinese workers showed backwash recycling
caused increases of turbidity, total solids, ammonia nitrogen (NH3
-N), permanganate index (CODMn
), and dissolved organic carbon. However, the recycling procedure had negligible impacts on the qualities of settled water and filtered water because most of the contaminants could be effectively removed by the conventional water treatment process.
Microbial fuel cells to detect groundwater pollution events
Work carried out in Tanzania provided an initial assessment and proof-of-concept
of in-situ MFC sensors for the non-expensive monitoring of faecal pollution in groundwater.In-situ MFC sensors have the potential to provide an affordable continuous measurement tool for groundwater quality at low cost and low maintenance, by creating a current response to significant faecal pollution without the addition of chemicals or an external power input. To progress beyond the proof-of-concept of the working prototypes proposed and evaluated in this study, further optimisations and the mathematical refining of the current response interpretation would be essential.
Effects of sulfate on heavy metal release from iron corrosion scales
Chinese workers using experimental pipe loops carried out a study to identify and evaluate the release of trace heavy metals from scale in water mains
under changing source water conditions They showed that heavy metal releases of Mn, Ni, Cu, Pb, Cr and As could be rapidly triggered by sulfate addition but the releases slowly decreased over time. Heavy metal release was more severe in pipes transporting groundwater (GW) than in pipes transporting surface water (SW). This study highlights the possible side effects of changing water sources feeding distribution sytems.
Biologically active filters (BAF) and contaminants of emerging concern (CEC)
US workers carried out bench scale studies
to see if existing filters in water treatment plants can be converted into BAF to treat a number of CECs. The study demonstrated that GAC BAFs with and without pre-ozonation are an effective and advanced technology for treating emerging contaminants. On the other hand, pre-ozonation is needed for dual media BAFs to remove CECs. The most cost effective operating conditions for dual media BAFs were a 10 minute empty bed contact time with the application of pre-ozonation.
Waterborne transmission of protozoan parasites 2011-2016
A recent review provides a comprehensive update of worldwide published data
on waterborne parasitic protozoan outbreaks largely between January 2011 and December 2016. At least 381 outbreaks attributed to waterborne transmission of parasitic protozoa were documented during this time period. Although nearly half (49%) of reports occurred in New Zealand, 41% of the outbreaks in North America and 9% in Europe most outbreaks probably occurred in countries lacking facilities to investigate and publish data . The most common etiological agent was Cryptosporidium
spp., reported in 63% (239) of the outbreaks, while Giardia
spp. was mentioned in 37% (142). No outbreaks attributed to other parasitic protozoa were reported.
Pulsed light disinfection
A very thorough review
of the use of pulsed light for disinfection of foods and water has recently been published. Although mainly focussed on food it flags up the potential of this technology for drinking water disinfection.
Simple kits for detection of indicator bacteria using simple colorimetric and electrochemical methods.
Workers in the United States have developed simple transparency-based electrochemical and paper-based colorimetric analytic detection platforms
as complementary methods for food and waterborne bacteria detection from a single assay. Using enzymes long established for identifying E. coli
and enterococci low concentrations (101
CFU/mL) of pathogenic and nonpathogenic E. coli
isolates and (100
CFU/mL) E. faecalis
and E. faecium
strains were detected within 4 and 8 h of pre-enrichment. The methodology is not sensitive enough for direct monitoring of drinking water.
MPN method for Legionella enumeration
is an opportunistic pathogen of major concern. The current large volume quantitative method employs membrane filtration (MF) and selective culture on GVPC agar followed by confirmation of isolates by serology (ISO 11731-2). A recent study
compared the performance of a novel MPN method (Legiolert/Quanti-Tray) with the ISO 11731-2 membrane filtration method for the enumeration of Legionella pneumophila
from 100 ml potable water and related samples. Data from a multi-laboratory study analysed according to ISO 17994 showed that Legiolert™/Quanti-Tray® yielded on average higher counts of L. pneumophila
. The Legiolert medium had a high specificity of 96·4%. The new method represents a significant improvement in the enumeration of L. pneumophila
from drinking water-related samples.
WHO review of turbidity
WHO has published a technical brief
providing information on the uses and significance of turbidity in source water and drinking-water. Practical guidance is provided on the implications of turbidity for water safety at each step of the water supply chain, from catchment through to the point of use.
WHO Guidelines for Drinking Water Quality- First Addendum
WHO has re-issued the 4th Edition of Guidelines for Drinking Water Quality integrated with the first addendum previously issued separately in 2016. ( full updated guidelines
) The changes arising from the addendum are separately documented (addendum changes
Chemical background documents for the development of the Guidelines for drinking-water quality
Removal of enteric viruses and possible surrogates by membrane filtration
Japanese workers have evaluated the removal
of three human enteric viruses and one murine surrogate by direct microfiltration and ultrafiltration. They also compared the removal of these with the removal of two bacteriophages (MS2 and φX174) and pepper mild mottle virus (PMMoV). They concluded that PMMoV appears to be a suitable surrogate for human enteric viruses for the assessment of the efficacy of membrane filtration processes to remove viruses, whereas MS2 and φX174 do not.
Flow cytometry as an alternative to heterotrophic plate counts.
A grroup of Belgian, Dutch and Swiss workers have published a second paper
supporting the use of flow cytometry (FC) as a more rapid tool for testing water mains after repair than the conventional heterotrophic plate counts.(HPC). When water mains are opened it is customary to carry out HPC and wait until counts from the main and the flushing water are the same before returning to supply.. FC and HPC do not directly correlate since FC counts include the 99%+ of microorganism which are not cultivatable by HPC but FC can give results within 15 minutes of receipt in the laboratory rather than the 18hr+ needed for HPC. Mains cleared by FC for return to supply were subsequently shown to meet the criteria set by HPC. The authors contend that FCM provides a faster, more descriptive and more representative quantification of bacterial abundance in drinking water. ( see also previous item “Flow cytometry for follow-up of water mains after maintenance
Effects of sulfate on heavy metal release from iron corrosion scales in drinking water distribution system
A recent Chinese study showed that sulfate could trigger heavy metal release from iron corrosion scales and strong correlations exist between the releases of total iron and heavy metals. In experimental pipe loops heavy metal releases of Mn, Ni, Cu, Pb, Cr and As could be rapidly triggered by sulfate addition but the releases slowly decreased over time. Heavy metal release was more severe in pipes transporting groundwater (GW) than in pipes transporting surface water (SW).
This may have implications for changes in source of supply to a network
Safe drinking water and waterborne outbreaks
A recent paper in the Journal of Water and Health has reviewed published details of waterborne disease
outbreaks between 2000 and 2014. The main causes for contamination were: for groundwater, intrusion of animal faeces or wastewater due to heavy rain; in surface water, discharge of wastewater into the water source and increased turbidity and colour; at treatment plants, malfunctioning of the disinfection equipment; and for distribution systems, cross-connections, pipe breaks and wastewater intrusion into the network. Pathogens causing the largest number of affected consumers were Cryptosporidium
, norovirus, Giardia
, and rotavirus.
Neonatal heart defects and DBPs
A case-control study
carried out in Massachusetts looked at 904 babies with nonchromosomal congenital anomalies of the heart and circulatory system and individually matched 10 controls per each case from all live births based on week of conception, for a total study population of 9,944. The very detailed paper showed a number of significant associations between certain specific birth defects and certain DBPs.
Elimination of Naegleria fowleri from bulk water and biofilm
Although primary amoebic encephalitis caused by Naegleria fowleri can only be contracted by inhalation, its presence in drinking water is still of concern and at least one fatality has been associated with drinking water. The amoeba requires warm water around 25°C and is unlikely to present a threat in public water supplies in the UK. A recent Australian study
has shown that a concentration of 1mg/l of chlorine is sufficient to eliminate Naegleria fowleri
from a drinking water system and prevent re-colonisation.
Water hardness and cardiovascular disease
Since at least the 1970s there have been a large number of studies exploring the possible association between drinking water hardness and heart disease (CVD) with no definitive conclusion except that more studies are needed. There has nevertheless been a general acceptance that hard water may have a protective effect in relation to cardiovascular disease. After a review of 643 potential studies
studies a meta-analysis of 7 studies was carried out by Italian workers. The study concludes that hard water consumption seems to be protective against CVD. However, the high heterogeneity (I2
= 75.24, p
-value = 0.001 for calcium; I2
= 72.96, p
-value = 0.0024 for magnesium) and the existence of publication bias limits the robustness and generalizability of these findings. Unsurprisingly it suggests that further high-quality studies are needed to reproduce and confirm these results.
Waterborne outbreaks of protozoal infections.
A review of waterborne outbreaks
of protozoal infections between 2011 and 2016 has been published. At least 381 outbreaks attributed to waterborne transmission of parasitic protozoa were documented during this time period. The nearly half (49%) of reports occurred in New Zealand, 45% in North America and 6% in Europe. The most common etiological agent was Cryptosporidium
spp., reported in 63% (240) of the outbreaks, while Giardia
spp. was mentioned in 37% (141). No outbreaks attributed to other parasitic protozoa were reported. The review notes that countries most likely to be affected lack adequate surveillance systems and many more outbreaks are likely to have occurred.
New DBPs in tap water.
A Chinese study
has demonstrated 13 new polar phenolic chlorinated and brominated disinfection byproducts (Cl- and Br-DBPs) in simulated chlorinated drinking water. Disinfectant, contact time, and pH all affected the formation of the 13 new DBPs and gallic acid was confirmed to be the precursor of all 13. 12 of the 13 new DBPs were detected in 16 tap water samples obtained from major cities in East China, at total levels from 9.5 to 329.8 ng/L. The concentrations of the new DBPs were higher in samples with source waters containing higher bromide levels.
Novel multifunctional composite material removes a wide range of impurities from water.
A team of Spanish and German workers have developed a novel material which can remove a wide range of contaminants from water
. It is a supported ionic liquid phase (SILP) composite where a polyoxometalate-ionic liquid (POM-IL) is immobilized on porous silica, giving the heterogeneous SILP. The water-insoluble POM-IL is composed of antimicrobial alkylammonium cations and lacunary polyoxometalate anions with heavy-metal binding sites. The lipophilicity of the POM-IL enables adsorption of organic contaminants. The silica support can bind radionuclides.
Guide to water competition
Flow cytometry for follow-up of water mains after maintenance
Belgian workers have compared the use of flow cytometry (FCM) with conventional bacterial plate counts
for determing when a repaired main was fit to return to service. FCM proved to be a more conservative test than plating, yet it yielded immediate results whereas conventional plate counting required at least 24 hours. Application of these FCM methods can therefore avoid long unnecessary waiting times and large drinking water losses.
Potential gene-based tool for pathogen detection in environmentaal samples
Nucleic acid sequence-based amplification (NASBA)
is a sensitive and efficient molecular tool for amplification of RNA and has been widely adopted in clinical diagnostics. NASBA has qualities that should be advantageous for analysis of environmental samples, such as short reaction times, high sensitivity, and not readily affected by inhibitory substances that are often abundant in environmental samples. This review explores advantages and drawbacks of NASBA as a tool for environmental analyses. (wikipedia
Evaluating UV-C LED disinfection performance
A dual-wavelength UV-C LED unit, emitting at peaks of 260 nm, 280 nm, and the combination of 260|280 nm together was evaluated for its inactivation efficacy and energy efficiency at disinfecting Escherichia coli
, MS2 coliphage, human adenovirus type 2 (HAdV2), and Bacillus pumilus
spores, compared to conventional low-pressure and medium-pressure UV mercury vapor lamps All sources were equally effective for E.coli
. While the 260nm LEDwas most effective for MS2, the medium pressure UV was most effective for HAdV2 and Bacillus pumilus
. For UV-C LEDs to match the electrical efficiency per order of log reduction of conventional LP UV sources, they must reach efficiencies of 25–39% or be improved on by smart reactor design.
Impact of fracking on drinking water resources
USEPA has released a review of available scientific information concerning the relationship between hydraulic fracturing activities and drinking water resources in the United States
. The review found scientific evidence that hydraulic fracturing activities can impact drinking water resources under some circumstances. Because of data gaps and uncertainties, it was not possible to fully characterize the severity or frequency of impacts.
Businesses offered one-stop-shop for energy and water.
A new partnership will offer a ‘one-stop-shop’ for businesses to secure deals for their energy and water consumption all in a single place. Scotland's incumbent water retailer Business Stream will manage the water services of the new multi-utility offering, while consultancy firm Utilitywise will oversee energy provision.
The all-in-one utility service
will initially be available to all organisations in Scotland, before being introduced to companies in England when the water retail market opens for competition in April 2017.
Business Stream – which will manage the water services – and Utilitywise – which will oversee energy provision – are hoping to engage small and medium-sized businesses (SMEs) with the new offering, as they may not have dedicated procurement teams or the weight of a large company to agree preferential rates with energy suppliers. The introduction of a one-stop utility offer comes as the water industry prepares for retail competition to be introduced for non-domestic water customers in England in April next year. The Government-led water retail competition strategy will effectively allow businesses to switch suppliers of water retail services; opening the water and wastewater (sewerage) retail market to new water companies and encouraging greater innovation within the water sector.
Inactivation of E. coli by copper and silver wire in the presence of synthetic sunlight for safe drinking water
using a pure culture of E.coli
compared the use of copper wire, artificial sunlight, both separately and in combination, and silver wire for the inactivation of the bacteria in water.. The studies showed that an improved rate of bacterial inactivation was achieved using the combined Cu/sunlight treatment method compared to either treatment applied independently. When given independently, the Ag wire treatment was more effective than the Cu wire treatment. Unfortunately the combination of silver wire and sunlight was not investigated. ( This work needs to be taken forward to a real world scenario before the authors claim that copper/sunlight combination method has a great potential to be used as a low-cost, re-useable, low-maintenance method of choice for purification of contaminated drinking water can be validated)
Removal of Cr(VI) from water by electrocoagulation
There is growing concern over Cr(VI) in drinking water and future legislation is a possibility. US workers have shown that passing an electric current between iron electrodes
can effect the reduction of mutagenic Cr(VI) in water to relatively harmless Cr(III).
Pathogenic features of heterotrophic plate count bacteria (HPC) from drinking-water boreholes
A recent paper looked at the pathogenic potential of HPCs
from untreated borehole water used for humen consumption by determining haemolytic properties and a range of relevant enzymes.and antibiotic sensitivity profile.They also looked at effect on a tissue culture cell line. They concluded that that the prevailing standards for HPCs in drinking water may expose humans with compromised immune systems to undue risk.
Discover Water launched
is a collaborative project which gives a comprehensive range of data covering water quality, public health, customer service and environmental aspects of water and sewerage services.. Led and funded by water companies, it has been delivered by an independent third party and overseen by a sector-wide group, including the sector’s regulators and consumer watchdog. The information used on Discover Water is already separately published by water companies, Ofwat, Defra, Drinking Water Inspectorate, Environment Agency and the Consumer Council for Water.
Background papers on drinking water and groundwater.
The upcoming WileyInternational Encyclopedia on Geography will include very detailed and informative sections looking at global groundwater
resources and their exploitation and also global availability, distribution of, and access to drinking water.
Removal of Naegleria fowleri from a drinking water distribution system
Workers in Australia have shown that a concentration of 1mg/l of chlorine was sufficient to eradicate Naegleria fowleri
from both the bulk water and biofilm in a drinking water distribution system and prevent recolonisation.
Virus removal requirement for potable use of recycled water
A discussion paper
suggests that the conventionally accepted 12 log reduction for safe use of recycled water for drinking may be too lax and a further 2 log could be appropriate.
Review of Health Outcome Targets
UKWIR has published a “Review of health outcome targets adopted worldwide for assessing the microbiological safety of drinking water”. The review
looks at 7 countries and concludes that there is a variety of approaches. Some countries use Disability Adjusted Life Years (DALY)as a metric while others prefer Level of Risk of Infection. Both approaches require some measure of the pathogen burden and while Quantitatve Risk Assessment (QMRA) is invariably used there is no standard framework for the exercise and different approaches have been used which vary in their complexity.
Direct DOC and nitrate determination in water using dual pathlength and second derivative UV spectrophotometry
A recent paper in Water Research describes how it is possible to measure simultaneously both dissolved organic carbon (DOC) and nitrate in water without the need for filtration. Based on several hundred samples from a number of samll rivers, comparison between the proposed method and the standardised procedures for nitrate and DOC measurement gave a good agreement for both parameters for ranges of 2–100 mg/L nitrate and 1–30 mg/L DOC.
Managing discolouration risk in trunk mains
A recent paper assesses the applicability of cohesive layer theories to manage discolouration
and describes a steady state empirical modelling tool that describes the process of particulate material accumulation. Results from independent field experiments across the UK and internationally showed hydraulically induced mobilisation, or effectively cleaning, once imposed system shear stress exceeds normal conditions. The experiments highlighted the accumulation of material layers as a continuous and ubiquitous process, such that fully clean pipes can never exist and help explain how discolouration risk changes over time. A major practical implication of the novel understanding demonstrated in the paper is that discolouration risk in trunk mains can be simply managed by pro-active strategies that regularly vary the hydraulic conditions. This avoids the need for disruptive and expensive out of service invasive interventions yet offers operators a cost-effective long-term strategy to safeguard water quality.
Efficacy of water treatment processes and endemic gastrointestinal illness
A Swedish paper examines endemic AGI
( acute gastrointestinal illness) and the relationship with pathogen elimination efficacy in public drinking water treatment processes. Data of all telephone calls to the Swedish National Healthcare Guide between November 2007 and February 2014 from twenty Swedish cities were obtained and calls concerning vomiting, diarrhea or abdominal pain (AGI calls) were separated from other concerns (non-AGI calls). Information on which type of microbial barriers each drinking water treatment plant in these cities have been used were obtained, together with the barriers’ theoretical pathogen log reduction efficacy. To achieve one general efficacy parameter for each plant, a weighted mean value of the log reductions (WLR) was calculated. Populations receiving drinking water produced with higher total log reduction was associated with a lower relative number of AGI calls. In overall, AGI calls decreased by 4% (OR = 0.96, CI: 0.96–0.97) for each unit increase in the WLR. The findings apply to both groundwater and surface water study sites, but are particularly evident among surface water sites during seasons when viruses are the main cause of AGI. This study proposes that the endemic level of gastroenteritis can indeed be reduced with more advanced treatment processes at many municipal drinking water treatment plants. (it is to be expected that the water supplies always met the regulatory standards although this is not specifically stated in the abstract
Development and validation of a method for the analysis of more than 500 pesticides and drugs in water.
A novel, fully automated contaminant screening method
based on an integrated sample preconcentration and liquid chromatography coupled to high resolution mass spectrometry (SPE-UHPLC-HRMS) has been developed. The method enables the simultaneous semi quantitative analysis of 539 compounds (pesticides and drug residues), in 36 min with only 5 mL of water. Method validation was achieved through studies of repeatability, selectivity, linearity and matrix effect. Application to 20 tap water samples collected in and around Paris showed the presence of 34 different compounds all with concentrations below the European Union limit for drinking water of 0.1 μg/L,. Pesticides and transformation products frequently found in water resources such as atrazine and its metabolites, hexazinone, oxadixyl, propazine and simazine were detected. Drug residues such as valsartan and carbamazepine, usually not monitored, were also found.
Pollutants from the EU Watch List: a review of their occurrence and water-treatment options
Micropollutants are found in aquatic environments all over the world and can have negative effects on plants, animals and humans. The EU recently adopted a ‘watch list’ of potential priority substances, including pesticides, pharmaceuticals and personal care products, that need to be monitored to determine their environmental risk.(list.) A new study reviews data
on their worldwide occurrence and options for their removal from wastewater, and from surface and groundwater used to produce drinking water.
Besides the substances previously recommended to be included by the Directive 39/2013/EU, namely two pharmaceuticals (diclofenac and the synthetic hormone 17-alpha-ethinylestradiol (EE2)) and a natural hormone (17-beta-estradiol (E2)), the first watch list of 10 substances/groups of substances also refers three macrolide antibiotics (azithromycin, clarithromycin and erythromycin), other natural hormone (estrone (E1)), some pesticides (methiocarb, oxadiazon, imidacloprid, thiacloprid, thiamethoxam, clothianidin, acetamiprid and triallate), a UV filter (2-ethylhexyl-4-methoxycinnamate) and an antioxidant (2,6-di-tert-butyl-4-methylphenol) commonly used as food additive. Since little is known about the removal of most of the substances included in the, particularly regarding realistic concentrations in aqueous environmental samples, this review aims
- overview the European policy in the water field;
- briefly describe the most commonly used conventional and advanced treatment processes to remove micropollutants;
- summarize the relevant data published in the last decade, regarding occurrence and removal in aqueous matrices of the 10 substances/groups of substances that were recently included in the first watch list ; and
- highlight the lack of reports concerning some substances of the watch list, the study of un-spiked aquatic matrices and the assessment of transformation by-products.
Global resilience analysis of water distribution systems
UK workers have developed a method to measure water systems' resilience to various failure modes
. The method identifies the range of failure impacts, reveals critical scenarios and shows that increased resilience to one failure mode may decrease resilience to another. Increasing capacity may not always improve resilience and may delay system recovery. The same degree of failure can result in very different levels of failure impacts.
Treatment of groundwater containing Mn(II), Fe(II), As(III) and Sb(III) by bioaugmented quartz-sand filters
High concentrations of iron (Fe(II)) and manganese (Mn(II)) often occur simultaneously in groundwater. Previously, Chinese workers demonstrated that Fe(II) and Mn(II) could be oxidized to biogenic Fe-Mn oxides (BFMO) via aeration and microbial oxidation, and the formed BFMO could further oxidize and adsorb other pollutants (e.g., arsenic (As(III)) and antimony (Sb(III)). These workers have now shown in the laboratory
that augmentation of quartz-sand filter columns with a Mn-oxidizing bacterium (Pseudomonas
sp. QJX-1) accelerated the formation of Fe-Mn oxides, resulting in an increase in As and Sb removal. Bioaugmentation intensified microbial degradation/utilization for the direct removal of pollutants and increased the formation of Fe-Mn oxides for the indirect removal of pollutants. They say that their study provides an alternative method for the treatment of groundwater containing high Fe(II), Mn(II) and As/Sb.
Cryptosporidium reclassification – able to complete lifecycle without a host
Parasites of the genus Cryptosporidium
are a major cause of diarrhoea and ill-health in humans and animals and are frequent causes of waterborne outbreaks. Until recently, it was thought that Cryptosporidium
was an obligate intracellular parasite that only replicated within a suitable host, and that faecally shed oocysts could survive in the environment but could not multiply. In light of extensive biological and molecular data
, including the ability of Cryptosporidium to complete its life cycle in the absence of a host
and the production of novel extracellular stages, Cryptosporidium
has been formally transferred from the Coccidia, to a new subclass, Cryptogregaria, with gregarine parasites. In this review
, we discuss the close relationship between Cryptosporidium
and gregarines and discuss the implications for the water industry.
Phage surrogate for adenovirus in disinfection studies.
Elucidating mechanisms by which pathogenic waterborne viruses become inactivated by drinking water disinfectants would facilitate the development of sensors to detect infectious viruses and novel disinfection strategies to provide safe water. Using bacteriophage viruses as surrogates for human pathogenic viruses could assist in elucidating these mechanisms; however, an appropriate viral surrogate for human adenovirus (HAdV), a medium-sized virus with a double-stranded DNA genome, needs to be identified. Bacteriophage PR772 has many similarities in structure and replication to HAdV. The inactivation of PR772 and HAdV by free chlorine had similar kinetics that could be represented with a model previously developed for HAdV type 2 (HAdV-2). US workers developed and tested a quantitative assay
to analyze several steps in the PR772 replication cycle to determine if both viruses being inactivated at similar rates resulted from similar replication cycle events being inhibited. Like HAdV-2, we observed that PR772 inactivated by free chlorine still attached to host cells, but viral DNA synthesis and early and late gene transcription were inhibited. Consequently, free chlorine exposure inhibited a replication cycle event that was post-binding but took place prior to early gene synthesis for both PR772 and HAdV-2.
THM and birth weight
Evidence for a relationship between trihalomethane (THM) or haloacetic acid (HAA) exposure and adverse fetal growth is inconsistent. Disinfection by-products exist as complex mixtures in water supplies, but THMs and HAAs have typically been examined separately. A multi-ethnic cohort study in Bradford
involving up to 7,438 singleton term babies investigated joint exposure at the individual level to THMs and HAAs in relation to birth weight. Pregnant women reported their water consumption and activities via questionnaire.
Among Pakistani-origin infants, mean birth weight was significantly lower in association with the highest versus lowest tertiles of integrated THM uptake but there were no associations among white British infants. Neither ingestion of HAAs alone or jointly with THMs was associated with birth weight.
Norovirus outbreak associated with bottled water.
suggest that in April 2016 over 4000 persons in Spain were infected with norovirus after drinking bottled water supplied from a bottling plant in Andorra. Norovirus genotypes 1 and 2 were reportedly found in the aquifer. It is suggested that this is the first outbreak associated with bottled water. There are claims that faecal indicator bacteria were not detected. At present no published results of epidemiological investigations have been seen.
Prosecution over Lead in Flint Michigan water
Following an investigation by the Michigan Attorney General into the events which resulted in exposure of residents of the town of Flint to high levels of lead in their drinking water over a period of 17 months, criminal charges have been laid against three people and a civil lawsuit have been brought against two engineering companies. The elevated lead levels were caused by failure to implement control measures to prevent corrosion of lead service pipes when the water source was changed in early 2014.
Two supervisors from the Michigan Department of Environmental Quality were charged on 20 April over their role in the decision not to implement corrosion control, and in relation to purposefully misleading the US Environmental Protection Agency into believing that a corrosion control system was being used for the Flint water supply, when in fact no such control existed. One supervisor was also charged over improperly manipulating the collection of water samples and removing test results from samples to be included in federal reports. An administrator at the Flint water treatment plant was charged with tampering with evidence by falsifying reports to state environmental officials, and wilful neglect of duty. (legal charges
) This emphasises the need for regulators to be constantly vigilant.
USEPA Health Advisories on per- and poly- fluoroalkyl substances
The USEPA has issued updated health advisories
for perfluorooctane sulphonate (PFOS) and perfluorooctanoic acid (PFOA) following an assessment of the latest peer-reviewed scientific evidence on the health risks of these chemicals. Both substances are members of a large group of man-made chemicals known as per- and poly-fluoroalkyl substances (PFASs) which were widely used in the manufacture of consumer and industrial products from the 1950s until the early 2000s when concerns over possible health and environmental effects resulted in progressive restrictions on use. The Health Advisory levels of 70 parts per trillion (0.070 μg/L) for both chemicals (alone or combined) are not enforceable regulatory limits, but are expected to guide public water suppliers and state agencies responsible for drinking water safety in their efforts to assess and manage potential health risks.
Recent DWI guidance on the Water Supply Regulations and on UV disinfection
Manganese and attention deficit
Studies of children and adolescents have associated excess manganese in the diet with attention deficits, but confounding factors in those studies have made it impossible to show a cause and effect relationship. Attention deficit hyperactivity disorder (ADHD) is the most prevalent neurobehavioral disorder in children, but its cause remains unclear and probably involves many different factors.
A new study
, published in Environmental Health Perspectives
, is the first study to establish a causal link between exposure to elevated manganese in the diet and attentional dysfunction in an animal model.
Microbial source tracking using PhyloChip
Workers have developed a molecular source tracking test
using the PhyloChip microarray (PhyloChip details) and machine-learning that detects and distinguishes fecal bacteria from humans, birds, ruminants, horses, pigs and dogs with a single test. The multiplexed assay targets 9001 different 25-mer fragments of 16S rRNA genes that are common to the bacterial community of each source type. Both random forests and SourceTracker (details)were tested as discrimination tools, with SourceTracker classification producing superior specificity and sensitivity for all source types. Validation with 12 different mammalian sources in mixtures found 100% correct identification of the dominant source and 84–100% specificity. Field test results indicate that machine-learning classification of PhyloChip microarray data can outperform conventional single marker tests that are used to assess health risks, and is an effective tool for distinguishing numerous fecal and environmental sources of pathogen indicators.
Norovirus cultured at last!
Human noroviruses -- the leading viral cause of acute diarrhea around the world -- have been difficult to study because scientists had not found a way to grow them in the lab. Now, more than 40 years after Dr. Albert Kapikian identified human noroviruses as a cause of severe diarrhea, scientists at Baylor College of Medicine have, for the first time, succeeded at growing noroviruses in laboratory cultures
of human intestinal epithelial cells.
DBP reduction using novel filter materials
The removal of natural organic matter (NOM) from source water may provide a more sustainable solution to disinfection by-products (DBP). A recent study
focused on the removal of NOM by novel filters, which could be retrospectively fitted to any conventional water treatment facility. The filters comprised stratified layers of a variety of media, including sand, Bayer residue, granular activated carbon (GAC), and pyritic fill. The filters were operated under two loading regimes, continuous and intermittent, at loading rates similar to recognised design standards. The most successful filter design comprised stratified layers of sand, GAC, and pyritic fill. Over the duration of a 240 day study, these filters obtained average dissolved organic carbon removal rates of 40%, and achieved average specific ultra-violet absorbance reductions from 2.9 to 2.4 L mg−1 m−1. The study demonstrates that these novel filters may be used to reduce NOM levels, thus reducing the potential for DBP formation. Such designs can incorporate the use of waste media, making the overall design more sustainable and robust.
DBPs and heart defects in babies.
A study in Massachusetts
examined nine cardiovascular defects in babies in relation to categorical DBP exposures including bromoform, chloroform, dibromochloromethane (DBCM), bromodichloromethane (BDCM), monobromoacetic acid (MBAA), dichloroacetic acid (DCAA), trichloroacetic acid (TCAA), and summary DBP measures (HAA5, THMBr, THM4, and DBP9). A number of associations were detected.
E coli can survive but not regrow in distribution.
A recent study
investigated the fate of E. coli
in drinking water, specifically addressing survival, biofilm formation under shear stress, and regrowth in a series of laboratory-controlled experiments. It showed the extended persistence of three E. coli
strains (two enteric isolates and one soil isolate) in sterile and nonsterile drinking water microcosms at 8 and 17°C, with T90 (time taken for a reduction in cell number of 1 log10 unit) values ranging from 17.4 ± 1.8 to 149 ± 67.7 days. Furthermore, each strain was capable of attaching to a surface and replicating to form biofilm in the presence of nutrients under a range of shear stress values (0.6, 2.0, and 4.4 dynes [dyn] cm-2
BioFlux system; Fluxion); however, cell numbers did not increase when drinking water flowed over the biofilm (P > 0.05 by t test). Finally, E. coli
regrowth within drinking water microcosms containing polyethylene PE-100 pipe wall material was not observed in the biofilm or water phase using a combination of culturing and Q-PCR methods for E. coli. The work concludes that when E. coli
enters drinking water it has the potential to survive and attach to surfaces but that regrowth within drinking water or biofilm is unlikely.
Failure prediction for cast iron pipes.
An Australian, UK and USA consortium has carried out a 5 year project on Advanced Condition Assessment and Pipe Failure Prediction
. The project addressed four questions - How, when, and where will pipes fail within the network?; How do we assess the condition of the pipe cost effectively?;. How do we calculate pipe deterioration rates accurately with respect to the pipe environment?;. How do we assess the time-dependant probability of failure along the pipeline?The key findings of the project have been summarised in an article in Advances in Water Research.
Graphene oxide and sunlight for water purification
A team of engineers at Washington University in St. Louis has found a way to use graphene oxide sheets to transform dirty water into drinking water
. The new approach combines bacteria-produced cellulose and graphene oxide to form a bi-layered structure with light-absorbing graphene oxide filled nanocellulose at the top and pristine nanocellulose at the bottom.
Light radiates on top of the biofoam and converts into heat because of the graphene oxide but the heat dissipation to the bulk water underneath is minimized by the pristine nanocellulose layer which acts as a sponge, drawing water up to the graphene oxide where rapid evaporation occurs. The resulting fresh water can easily be collected from the top of the sheet.
The team hopes that for countries where there is ample sunlight, such as India, it will be possible to take some dirty water, evaporate it using the biofoam material, and collect fresh water.
Manganese in Drinking Water and Cognitive Abilities and Behavior at 10 Years of Age.
A recent cohort study involving Indian children
investigated the relation between manganese in water (W-Mn) and the development of cognitive abilities and behaviour over the first 10 years of life. The study concludes that elevated prenatal W-Mn exposure was positively associated with cognitive function in girls, while boys appeared unaffected. However, early-life W-Mn exposure appeared to adversely affect children’s behavior.
Relationships among fecal indicator bacteria, microbial source tracking markers, and associated waterborne pathogen occurrence.
A US group have carried out a study to predict occurrence of waterborne pathogens in water and streambed sediments
using a simple statistical model that includes traditionally measured faecal indicator bacteria, environmental parameters and source allocation, using microbial source tracking markers as predictor variables. They measured Campylobacter, Serratia, and Salmonella numbers in waterand sediments and the virulence gene that carries Shiga toxin, stx2
. Pathogens were detected in water more often than in underlying sediments. Relationships between pathogens and indicator variables were generally inconsistent and no single indicator adequately described occurrence of all pathogens.
Novel membrane for lead removal
Workers in Singapore developed a novel zirconium phosphate modified polyvinyl alcohol (PVA)-PVDF membrane for removal of lead from water
. The maximum adsorption capacity was 121.2 mg-Pb/g at pH 5.5, much higher than other reported adsorptive membranes. The membrane exhibited a higher selectivity for lead over zinc with a relative selectivity coefficient (Pb2+
) of 9.92. The filtration study showed that the membrane with an area of 12.56 cm2
could treat 13.9 L (equivalent to 73,000 bed volumes) of lead containing wastewater with an influent concentration of 224.5 μ g/L to meet the maximum contaminant level of 15 μ g/L. The membrane also performed well with lead-spiked reservoir water and had a good reusability in its applications.
Drinking water contaminants from epoxy resin-coated pipes
In this study
6 locations with different age epoxy linings of drinking water pipes done using two distinct technologies were studied. While bisphenol F, 4-n-nonylphenol, and 4-t-octylphenol were rarely found and in trace concentrations, BPA was detected in majority of samples. Pipes lined with the older technology (LSE) leached more BPA than those with more recent technology (DonPro): maxima in cold water were 0.25 μg/L and 10 ng/L, respectively. Incubation of water in pipes 8–10 h prior to sampling increased BPA concentration in cold water 1.1–43-fold. Hot water temperature caused even more BPA leaching - at maximum 23.5 μg/L. The influence of ageing of epoxy lining on BPA leaching on could be shown in case of LSE technology: locations with 8–9 years old lining leached 4–20-fold more BPA compared to a location with 2-year-old lining
. Analysis of metals showed that epoxy lining can reduce especially iron concentration in water. No significant burden to water could be shown by the analyzed 72 volatile organic compounds, including epichlorhydrin, precursor used in epoxy resin. Estrogenicity was detected in water samples with the highest BPA loads. Comparable responses of two yeast bioreporters (estrogen receptor α and BPA-targeted) indicated that bisphenol-like compounds were the main cause of estrogenicity. Compared to the estimated average daily BPA exposure, additional BPA load via cold drinking water in the studied locations was low, maximum 8.7%. The authors suggest that hot water should also be considered as exposure source due to higher BPA concentrations. Epoxy lined locations should be monitored in future in order to evaluate ageing process and control increasing leaching of potentially harmful chemicals.
Protecting Surface Water for Health
WHO has just published a very comprehensive book which provides a structured approach to the assessment and management of drinking-water quality related risks in surface-water catchments. The publication will support the development and application of water safety planning where source-water protection is a key element in the provision of safe drinking-water. This book is a valuable adjunct
to the already copious information on the WHO Water Supply Portal
Quantitative Microbiological Risk Assessment
WHO has recently published a book
which for the first time synthesizes the current knowledge on QMRA to facilitate its application in the practice of water supply, water reuse and water recreation to support the management of risks associated with faecal pathogens in the waterrelated context. A four-step QMRA framework harmonized across the water supply, reuse and recreation contexts is presented, and the value of QMRA for water safety management is described. Guidance is provided to support the successful implementation of QMRA. Key aspects include: the role of interaction between risk managers and risk assessors; interpretation of scientific data including uncertainty; and interpretation of quantitative results. Many examples including six full case studies are described.
Climate change implications for UK water supplies.
The independent Committee on Climate Change has produced a very comprehensive report on the future impact of climate change
for the United Kingdom based on the inputs of a wide range of experts.
The report states that “climate change is projected to reduce the amount of water in the environment that can be sustainably withdrawn whilst increasing the demand for irrigation during the driest months. At the same time the growing population will create additional demands on already stretched resources in some parts of the country. Even low population growth and modest climate change scenarios suggest severe water supply deficits, and with high population growth and more severe climate change these deficits deepen and by the 2050s extend across the UK. Whilst there is significant action already underway, there is an urgent need for longer-term water resource planning to assess the scale of risks and consider strategic options, more co-ordinated action to ensure resilient supplies especially in times of drought, and further steps to achieve the ambitious reductions in water demand and leakage that are likely to be required. Otherwise there could be increasingly difficult trade-offs between the needs of industry, farming and the public water supply, and the ecological status of rivers, lakes,estuaries, and groundwater.
The recent vote in favour of leaving the European Union does not change the overall findings of this risk assessment. However, the magnitude of individual climate change risks and opportunities could be affected if legislation, policy and funding derived from the EU, relevant to climate change adaptation, are changed. Important areas include the Common Agricultural and Fisheries Policies, the Water Framework, Bathing Water, Birds, Habitats, Floods, Urban Waste Water Treatment and Solvency II Directives, and the European Structural Investment Fund. Compensatory UK measures may be stronger or weaker than their EU equivalents.”
Microbes can produce halogenated organic pollutants
For a long time it has been assumed that halogenated organic compounds are only produced and released by human activity. However, in recent years, over 5,000 naturally-occurring organohalogen compounds have been identified, and evidence suggests that the cycling of halogens e.g. chlorine, bromine in soils is largely driven by microbial processes
. Workers in Germany studied soil in a pristine forest by analysing the whole gene pool found in the earth, the metagenome. They did not isolate individual organisms but identified all of the great diversity of genes from bacteria, fungi and archaea coding for halogenating and dehalogenating enzymes.
Water Quality interventions in low-income countries can have adverse effects.
A recent paper compares results of blind and open trials
of water quality interventions. Although open trials may be affected by reporting bias, evidence suggests that despite instructions to the contrary, placebos may encourage control group participants in blinded trials to cease practicing traditional water treatment practices such as boiling in the mistaken belief that they are protected by an active intervention. The paper references an interesting study (link) in which a sham filter shown to have no effect in the lab actually removed 90% of fecal indicator bacteria in the field (probably due to accumulated biofilm).
Pinpointing leaks by noise loggers
A paper from Concordia University,Montreal notes that noise loggers have usually been used only for localizing leaks while other tools were used for locating and pinpointing. It describes the development of regression and artificial neural network (ANN) models to localize and locate leaks in water pipelines using noise loggers
. Several lab experiments were conducted to simulate actual leaks in a sample ductile iron pipeline distribution network with valves. The noise loggers were used to detect these leaks and record their noise readings. The recorded noise readings were then used as input data for the developed models. The ANN models outperformed regression models during testing. Moreover, ANN models were successfully validated using an actual case study.
Water treatment processes and endemic gastrointestinal illness.
Over a seven year period a Swedish study has examined all telephone calls from 20 cities to the Swedish National Health Guide relating to acute gastrointestinal illness (AGI) and related each one to the treatment applied to the person's drinking water
. Using the theoretical log reduction for various infectious agents by each treatment stage they calculated a weighted mean value (WLR) for the treatment applied to each water supply. The WLR in the plants varied between 0.0 and 6.4 units
Populations receiving drinking water produced with higher total log reduction was associated with a lower relative number of AGI calls. In overall, AGI calls decreased by 4% (OR = 0.96, CI: 0.96–0.97) for each unit increase in the WLR. The findings apply to both groundwater and surface water study sites, but are particularly evident among surface water sites during seasons when viruses are the main cause of AGI. This study proposes that the endemic level of gastroenteritis can indeed be reduced with more advanced treatment processes at many municipal drinking water treatment plants.
Perfluorinated chemicals in drinking water
The USEPA has issued advisory notices
in respect of 2 perfluorinated chemicals in water, namely perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). A maximum value of 0.07 micrograms per litre is recommended for each substance.
) (DWI Guidance
Disinfection of Escherichia coli and Pseudomonas aeruginosa by copper in water
Storage in copper vessels has been shown to reduce microbes, but inactivation kinetics of enteric bacteria in water by copper alone needs to be understood. A recent paper characterized inactivation kinetics
of Escherichia coli
and Pseudomonas aeruginosa
by dissolved ionic copper in water. Reductions of E. coli
and P. aeruginosa
increase with increasing dose. At 0.3 mg/L, there was a 2.5 log10
reduction of E. coli
within 6 hours. At 1 and 3 mg/L, the detection limit was reached between 3 and 6 hours; maximum reduction measured was 8.5 log10
. For P. aeruginosa
, at 6 hours there was 1 log10
reduction at 0.3 mg/L, 3.0 log10
at 1 mg/L, and 3.6 log10
at 3 mg/L. There was no significant decline in copper concentration. Copper inactivates bacteria under controlled conditions at doses between 0.3 and 1 mg/L. E. coli
was inactivated more rapidly than P. aeruginosa
. Copper at 1 mg/L can achieve 99.9% inactivation of P. aeruginosa
and 99.9999997% inactivation of E. coli
over 6 hours, making it a candidate treatment for stored household water.
Effects of plumbing systems on DBPs
Trihalomethanes (THMs) in plumbing pipes and hot water tanks
were observed to be 1.1–2.4 and 1.6–3.0 times, respectively, to THMs in the supply system, while haloacetic acids (HAAs) were 0.9–1.8 and 1.2–1.9 times, respectively, to HAAs in supply. (This supports the regulation of drinking water quality being applied at the point of use
Removal of septic and musty odours.
Chinese workers studied the removal of musty and septic odours in a Water Treatment Plant
equipped with coagulation, sedimentation, ozonation, biological activated carbon (BAC) filtration, sand filtration, and chlorination in succession.
The source water was constantly associated with septic and musty odors. Flavor profile analysis (FPA) results showed that Geosmin and 2-MIB, with an average OAV of 4.54 and 1.38, respectively, were the major odorants for musty odour, while bis(2-chloroisopropyl) ether, DEDS (di-ethyl disulphide) and DMDS (di-methyl disulphide) with an average OAV ( odour activity value)of 2.35, 1.65 and 0.78, respectively, might be responsible for the septic odour.
While the musty odour could be removed effectively through the combination of ozonation and BAC, the septic odour and associated odourants required further treatment with sand filtration and chlorination for complete removal. It is clear that the advanced treatment process was effective for the treatment of source water containing complicated odourants. It should be noted that the sedimentation process needs careful management because release of odourants may occur during the treatment. The result of this study will be helpful for the mitigation of odors in WTP using source waters suffering from complicated odor problems.
Impact of improving treatment on distribution system water quality
A recent 2-year study
utilised four parallel pilot distribution systems (PDS) and a range of simple tools to assess the impact improving treatment had on the water quality within the distribution system. Particle counting was more effective than turbidity to assess the impact of increasing treatment on sediment load entering the PDS while UV254 was as informative as dissolved organic carbon to assess organic load but has the additional potential benefit of on-line measurement. However, variability in water quality entering the PDS was often greater than measurable changes occurring within the PDS. It was critical to compare water quality entering the distribution system with the water quality at a defined point within the distribution system (at known hydraulic detention time) to enable effective assessment of water quality changes. Therefore, effective use of these simple tools requires monitoring of both inlet and distribution system locations, together with long term trending to monitor and compare changes within the system.
EU call for open access to all scientific papers
E.U. member states agreed on an ambitious new open-access (OA) target under which all scientific papers should be freely available by 2020
, but some observers are warning that the goal will be difficult to achieve. There are as yet no clear suggestions as to how this might be achieved but one suugestion is that papers should be made available in an institutional repository immediately on acceeptance for publication
The OA goal is part of a broader set of recommendations in support of open science, a concept that also includes improved storage of and access to research data.
Government loses track of its own research.
A recent independent report
into Government research spending has concluded that while approximately £5bn is spent annually on government research, there is no reliable breakdown of what that money is spent on or what happens to the studies. Many departments and arm’s length bodies do not collect information centrally about what research they have commissioned, and teams within departments and arm’s length bodies can conduct or commission their own research without the rest of the organisation knowing about it. There is however a publicly accessible database of all Defra commisssioned research which includes most if not all water supply related research.
“Deep water desalination”
A scheme described as deep water desalination
is proposed for Monterey Bay in California USA. The scheme will take cold water from well below the ocean surface and use it for cooling a computer facility before treating it by desalination. The proposed output is expressed in somewhat curious units as 25,000 acre feet per year. The water will be abstracted at a depth of 100 feet (sic) on the slope of a deep underwater canyon and the rejected brine discharged at a depth of 35 meters (sic) much further out from shore than the intake. Despite the idiosyncratic and arbitrary use of units the concept of using the water for more than one purpose is interesting.
The role of backwash in start-up of full-scale drinking water biofilters
The purpose of backwashing during the start-up period of rapid biofilters at drinking water treatment plants differs significantly from the purpose of backwashing during normal operation. During start-up, finished water quality is secondary, detachment of microorganisms must be minimized, dust present in the original filter media must be removed and inherent inoculation of the biofilter with water used for backwashing must be considered. Investigations over a 9-week start-up period
at a full-scale waterworks showed a strong correlation between suspended solids and turbidity, and that fine particles present in the original filter media were removed over a period of several weeks. In addition, after an initial period in which iron accumulated on the filter was not removed by backwash, iron was removed with 80% efficiency. Backwashing had 0% efficiency in removing manganese from the filter media. Practical conclusions include that shortened backwash procedures during start-up may be preferable, turbidity may be used as a surrogate for suspended solids in backwash effluent, filter media may be pre-treated by exaggerated backwashing to remove fine particles before start-up, and that a reasonable backwash procedure for future operation of the filter may be defined early in the start-up period.
Rapid detection of E.coli in contaminated water
Canaadian workers have developed a hydrogel-based rapid detection method for E.coli
in comtaminated waters. Using an integrated plunger-tube assembly containing the hydrogel matrix the system allows efficient, field deployable, rapid testing of water samples by simultaneously pre-concentrating and detecting E. coli
within one integrated unit. The workers were able to detect E. coli
concentrations of 4 × 106
to 4 × 105
within 5 min and 4 × 104
to 400 CFU mL−1
within 60 min.
Cryptosporidium and stunted growth
A Bangladeshi study
followed 392 babies for the first two years of life. Malnutrition was common in the children and 56% were significantly stunted by age 2. Children with Cryptosporidium
spp. infection had a greater than 2-fold increased risk of severe stunting at age two compared to uninfected children (odds ratio 2.69, 95% CI 1.17, 6.15, p = 0.019) independent of sex, income, maternal body-mass index, maternal education and weight for age adjusted z (WAZ) score at birth.. Cryptosporidium
infection is common (77%) in this cohort of slum-dwelling Bangladeshi children, and two thirds of the cases of infection detected were non-diarrhoeal. Both non-diarrheal and diarrheal infections are significantly associated with impairment of a child’s growth at 2 years of age. (the study does not show that there are any implications for otherwise well-nourished children).
Nanotechnology for arsenic removal
A team of Indian workers has developed a new treatment based on nanotechnology which purifies water, removes arsenic, and does this at a price affordable for the poorest communities
The team has manipulated silver nanoparticles, impregnated within a protective ‘cage’ built out of nanomaterials like aluminium and the chitin from crustacean shells. The resulting reaction breaks down the halocarbons of pesticides and other microbial contaminants into harmless metal halides and amorphous carbon. The technology requires no power and has no disposable parts. Field trials are under way. Although it can deliver safe water for less than $0.0007/litre it doesn't offer the prospect of large profits to investors when the main beneficiaries are the poorest communities.
Future impact of water shortage
The World Bank warns that by 2050, growing demand for cities and for agriculture would put water in short supply in regions where it is now plentiful – and worsen shortages across a vast swathe of Africa and Asia, spurring conflict and migration. The biggest economic hits due to water deficits were expected to occur in the Middle East, north Africa, central Asia, and parts of south Asia, the report found
. There would be virtually no impact on the economies of North America and western Europe but globally GDP could fall by around 6%.
New UK Clean Water Research Consortium
The recently established EPSRC Grand Challenge research centre TWENTY65
is tackling the challenge of sustainable clean water over the next 50 years through research and collaboration across the water industry. The consortium includes the Universities of Sheffield, Exeter, Imperial College, Manchester, Newcastle, and Reading, Key representatives from the UK Water Partnership have been appointed to the governance boards.
Lead in drinking water in large buildings
Lead results from 78,971 water samples collected in four Canadian provinces from elementary schools, daycares, and other large buildings
showed maximum concentrations reached 13,200 and 3890 μg/L following long and short stagnation periods respectively. High lead levels were persistent in some large buildings, reflected by high median values considering all taps, or specific to a few taps in the building. Simulations showed that, for most buildings, exposure to lead at the tap does not increase children's blood lead levels. However, buildings or taps with extreme concentrations represent a significant health risk to young children and could lead to acute exposure. For a few taps, the total daily lead intake reached the former World Health Organization (WHO) tolerable level for adults, suggesting potential health risks.
Destratification of raw water reservoirs
Southern Water has joined a growing number of water suppliers installing the ResMix source management technology
for tackling stratification in raw water reservoirs. The system works using an impellor to drive surface water into the reservoir depths which promotes vertical circulation. (This note is not an endorsement by FWR of the commercial technology
Taste of RO water.
European workers examined differences in taste between various remineralised drinking waters. Comparing tap waters and RO waters with and without remineralisation. Total dissolved solids (TDS) was a major determinant of the taste perception of water. In general, lowering mineral content in drinking water in the range examined (from <5 to 440 mg/L) shifted the sensory perception of water from fresh towards bitter, dry, and rough sensations. In addition, perceived freshness of the waters correlated positively with calcium concentration. The greatest fresh taste was found for water with a TDS between 190 and 350 mg/L. Remineralisation of water after reverse osmosis can improve drinking quality significantly.
Review of recent studies on UV-LEDs with various wavelengths for the inactivation of different microorganisms
A new UV source — ultraviolet light-emitting diode (UV-LED)
— has emerged in the past decade with a number of advantages compared to traditional UV mercury lamps.A recent article presents a comprehensive review of recent studies on UV-LEDs with various wavelengths for the inactivation of different microorganisms. The review notes that many inconsistent and incomparable data were found from published studies, which underscores the importance of establishing a standard protocol for studying UV-LED inactivation of microorganisms.
Evaluation of exposure scenarios on intentional microbiological contamination in a drinking water distribution network
A recent paper considers the implications of an intentional pathogenic contamination
in a drinking water distribution network . It investigates the effects of seeding duration and concentration, exposure pathway (ingestion via drinking of water and tooth brushing and inhalation by taking a shower) and pathogen infectivity on exposure and infection risk.It concludes that regardless of pathogen infectivity, if the seeding concentration is 106 pathogens per litre or more, infection risks are close to one.
Nitrogen accumulation in the ground
Storage tanks and chlorine -resistant bacteria.
A study examining more than 50 tap water samples found water had very few bacteria in buildings without cisterns but there was noticeable contamination in buildings where storage tanks were present or plumbing had been altered or otherwise disrupted.The problem was likely to have been caused by the plumbing changes or improperly maintained cisterns, opening the risk of bacterial resistance to disinfectants
. (The Reference given in the article relates to antibiotic resistance and from the abstract does not appear to contain anything about storage!) DWI published a report in 2002
on the benefits and disbenefits of storage within buildings which may be of interest.
Brass Fittings as a Source of Lead & Nickel in Drinking Water
UKWIR has published report 15/DW/04/16
, one of two reports on Stage 2 of ongoing research to increase understanding of how brass fittings contribute to lead and nickel concentrations in drinking water. It examines yields of lead and nickel, and the effect of the addition and cessation of phosphate dosing on brass fittings deployed on long term test rigs. It also examines the effect of chlorine or chloramine dosed water on leaching from a laboratory trial. It identifies situations where individual brass fittings or combinations of fittings can routinely yield a few µg/l of lead or nickel and circumstances where their respective Prescribed Concentration or Value (PCV), of 10 µg/l and 20 µg/l respectively, could be exceeded following periods of stagnation. The dosing of phosphate is shown to quickly reduce leaching of lead and nickel, whilst the cessation of dosing is shown to increase leaching within a few days.
Impact of Tap Water Lead Concentration on Blood Lead Levels in 1- to 5-Year-Old Children
A Canadian study looked at blood lead levels and cumulative lead exposure from tap water
in children from 1 to 5 years. The study concluded that in children 1–5 years of age, blood lead was significantly associated with water lead concentration with an increase starting at a cumulative lead exposure of ≥ 0.7 μg Pb/kg of body weight. In this age group, an increase of 1 μg/L in water lead would result in an increase of 35% of BPb after 150 days of exposure.
Plain water consumption in relation to energy intake and diet quality among US adults, 2005–2012
This recently published study
showed that a one percentage point increase in the proportion of daily plain water in total dietary water consumption was associated with a reduction in mean (95% confidence interval) daily total energy intake of 8.58 (7.87–9.29) kcal, energy intake from sugar-sweetened beverages of 1.43 (1.27–1.59) kcal, energy intake from discretionary foods of 0.88 (0.44–1.32) kcal, total fat intake of 0.21 (0.17–0.25) g, saturated fat intake of 0.07 (0.06–0.09) g, sugar intake of 0.74 (0.67–0.82) g, sodium intake of 9.80 (8.20–11.39) mg and cholesterol intake of 0.88 (0.64–1.13) g. The effects of plain water intake on diet were similar across race/ethnicity, education attainment, income level and body weight status, whereas they were larger among males and young/middle-aged adults than among females and older adults, respectively. Although US dietary habits are far from typical, the study conclusion that promoting plain water intake could be a useful public health strategy for reducing energy and targeted nutrient consumption in the US might be more generally applicable.
The role of tap water in public health and hydration
WaterUK has published a very informative report
which covers water consumption data , and public perceptions and concerns regarding their drinking water. Although the percentage of households drinking bottled water has increased from 30% in 1995 to 45% there is still a general satisfaction with tap water. The report contains a wealth of illuminating statistics and water supply professionals will find it well repays detailed reading.The report suggests that some consumers choose to take additional steps at home to filter tap water or use bottled water as their main source of drinking water domestically, which indicates a lack of trust, concerns over quality or cultural differences. These could readily be addressed with effective, coordinated and clear communication at both a local and regional level about the high quality of UK tap water and the benefits of drinking it.
Comparison between ultrafiltration and nanofiltration hollow-fiber membranes for removal of natural organic matter
Performance of water supply systems during mild to extreme droughts
The Environment Agency has published the results of a study seeking to understand the performance of different types of water supply
systems to a range of droughts, including those that are more severe than the worst case historical droughts, The results show that the case study water supply systems typically fall into three groups: Those that experience rapid failure; those that experience progressive failure; and those that exhibit low sensitivity or high resilience to drought.
Future global water demand
The International Institute for Applied Systems Analysis has published the results of its assessment of future global water demand
and concludes that demand for water could more than double by 2050, increasing pressure on already scarce water resources. Water efficiency and water saving measures could stabilize demand but if current trends continue, domestic and industrial water demand would more than double by the year 2050, and continue to increase after that.
Chemical background documents for the Guidelines for Drinking-water Quality – feedback requested
Evaluation of the potential for virus dispersal during hand drying: a comparison of three methods.
A recent study published in Water Research
compares the dispersion of MS2 phage when hands were dried using paper towels (PT), warm air hand drying (WAD)and jet air drying (JAD). Results showed that the JAD dispersed an average of >20 and >190-fold more PFU in total compared to WAD and PT at all distances tested up to 3 m (P < 0·01) respectively. Air samples collected around each device 15 min after use indicated that the JAD dispersed an average of >50 and >100-fold more PFU compared to the WAD and PT (P < 0·001), respectively. While not of direct relevance to Water Supply it does draw attention to an important aspect of hand drying
Water quality modeling in the dead end sections of drinking water distribution networks.
A new modeling approach for simulating disinfectant residuals in dead end pipes has been proposed
which accounts for both spatial and temporal variability in hydraulic and transport parameters. The model results show better agreement with field-measured concentrations of conservative fluoride tracer and free chlorine disinfectant than the simulations of recent dispersion reaction models published in the literature.
Low pressure UV/H2O,sub> treatment for the degradation of the pesticides metaldehyde, clopyralid and mecoprop
A recent paper in Water Research
describes the reaction kinetics for the three pesticides with low-pressure UV and hydrogen peroxide. Mecoprop was susceptible to both LP-UV photolysis and hydroxyl radical oxidation, and exhibited the fastest degradation kinetics, achieving 99.6% (2.4-log) degradation with a UV fluence of 800 mJ/cm2
and 5 mg/L hydrogen peroxide. Metaldehyde was poorly degraded by LP-UV photolysis while 97.7% (1.6-log) degradation was achieved with LP-UV/H2
treatment at the maximum tested UV fluence of 1000 mJ/cm2
and 15 mg/L hydrogen peroxide. Clopyralid was hardly susceptible to LP-UV photolysis and exhibited the lowest degradation by LP-UV/H2
among the three pesticides.
Aerobic spores as a surrogate for cryptosporidium oocysts in drinking water supplies
A recent review
of the use of spores as surrogate for oocysts concludes that aerobic spores, as well as exhibiting similar biology and survival to oocysts, are easy to detect and prevalent in the environment. The authors stress that the migration potential of spores and oocysts still needs to be compared.
Drinking Water Coagulant Recovery and Re-use
Workers in Qatar examined the individual and successive separation performance of several novel and existing ferric coagulant recovery purification technologies. Membrane & chemical purification of recovered water treatment coagulant
were studied and recovered coagulants were assessed with reference to treatment performance. Alkali-stripping coupled with activated carbon polishing performed the best and recovered coagulants achieved similar contaminant removal to virgin ferric sulphate.
Virus removal and integrity in aged RO membranes
A study by Spanish workers
using MS2 phage as a surrogate virus has shown that even when severe physical membrane damage toRO membranes lead to a reduction of salt rejection to 1.2 log (94%), the minimum rejection of MS2 phage, although reduced, stayed on or above 4 log.
Agar shortage threatened
There are reports
that agar, a material essential for many bacteriological procedures including heterotrophic plate counts carried out on drinking waters, is becoming scarcer and some suppliers are rationing supplies.
Algal toxin risk assessment
USEPA has produced an “Algal toxin risk assessment and management strategic plan for drinking water”. The document is very comprehensive
, covering the relevant US regulations, the health significance of algal toxins, and factors causing blooms, as well as analysis, monitoring and treatment. It also points up research gaps where further knowledge is needed.
Antibiotics in raw and treated drinking water
analysed a large range of veterinary and human antibiotics in raw and treated water. Using two analytical methodologies using solid-phase extraction and high-performance liquid chromatography-mass spectrometry they found that most of the antibiotics analysed were removed by an ozone/granular activated carbon combination. However danofloxacin and enrofloxacin which have an ionisable character and insufficient ozonation kinetic constant were not removed and chlorination proved to be ineffective in removing them.
Removal of naturally occuring organic matter and taste and odour-causing compounds
A paper by Korean workers
compares GAC., GAC + O3
and GAC + O3
for removal of natural organic matter and taste and odour compounds from water in a pilot plant.. Based on a comparison of the efficiencies and an economic analysis, the O3
+ GAC process was determined to be the optimal system for removing NOM and taste and odour compounds.
Automated determination and evaluation of water losses in water distribution systems
German workers note that using conventional methods and tools for determining detailed zonal water balances and performance indicators involves considerable efforts in manual data collection and processing. Hence, water balances mostly are determined for a whole network only. Unmetered components are often neglected or based on rough estimates. Their article
presents an approach to the automated determination of zonal water balances and its implementation as a software tool. The approach is demonstrated for a practical case.
A novel water treatment product
is being developed by Dr Theresa Dankovich which would enable safe drinking water to be produced by filtration through paper lined with silver and copper nanoparticles. The product, which is currently being patented, would be produced as a book, with each page being capable of treating up to 100 litres. The product is intended for emergency use or as a household point-of-use treatment.
Major Water Research grant
EPSRC, under its Water for All Grand Challenge, has awarded £3.9 million to a consortium of 6 Universities and 26 Companies
. The consortium will develop tailored solutions to the challenges of increasing population, ageing infrastructure, and the need to better protect the natural environment, all under conditions of uncertain climate change. It proposes development of a Hub that will revolutionise the way innovation is delivered to the UK water sector. The Hub aims to provide transformative leadership and accelerate and support innovation through partnerships for the co-production of knowledge across the water sector.
Microbiological Drinking Water Quality Assessment
A recent study compared several methods
for quantifying and discriminating between the different physiological states of a bacterial population present in drinking water. Flow cytometry (FCM), solid-phase cytometry (SPC), epifluorescence microscopy (MSP) and culture method performances were assessed using both chlorinated and non-chlorinated water. Total bacteria were quantified, viable and non-viable bacteria were distinguished using staining, and active cells were distinguished. Counts using microscopy and FCM were significantly correlated regarding total bacteria and active cells. Conversely, counts were not significantly similar using solid-phase and FCM for active bacteria. The R2A culture medium showed that bacterial culturability could be recovered after chlorination. This study highlights that FCM appears to be a useful and powerful technique for drinking water production monitoring.
Metformin- a non-hormonal endocrine disruptor.
US workers have shown Metformin
, a non-hormonal drug widely used in the treatment of diabetes, to act as an endocrine disruptor at environmentally relevant concentrations. It is among the most abundant of pharmaceuticals found in effluent and is structurally dissimilar from hormones.
Newly installed polyethylene pipes– short term quality impact of different cleaning methods
The influence of four different cleaning methods used for newly installed polyethylene (PEX) pipes on chemical and odor quality was determined using two different pipe brands. TOC concentration and threshold odor number values significantly varied between two pipe brands. Different cleaning methods impacted carbon release, odor, as well the level of drinking water odorant ethyl tert-butyl ether. Both pipes caused odor values up to eight times greater than the US federal drinking water odor limit. Organic chemicals released by PEX pipe were affected by pipe brand, fill/empty cycle frequency, and the pipe cleaning method selected by the installer.
Water Quality Modelling in the Dead End Sections of Drinking Water Distribution Networks
Dead-end sections of drinking water distribution networks are known to be problematic zones in terms of water quality degradation. Extended residence time due to water stagnation leads to rapid reduction of disinfectant residuals allowing regrowth. A recent paper by US workers
proposes a new approach for simulating disinfectant residuals in dead end pipes while accounting for both spatial and temporal variability in hydraulic and transport parameters.
Cooking , chlorine, chloramine and iodine.
A recent paper decribes how, in laboratory studies
, cooking with chlorinated or chloraminated water and iodised table salt resulted in the production of iodinated DBPs new to environmental chemists, toxicologists and engineers. 14 such compounds were identified and the toxicity of 9 of these was detrmined using a recently developed bioassay.
Disinfection by-products (DBP) and contact time
A recent Japanese study
has looked at the effect of longer retention times in distribution on formation of DBP. They looked at the formation of various disinfection byproducts (DBPs), including carbonaceous DBPs such as trihalomethane (THM) and haloacetic acid (HAA), and nitrogenous DBPs such as nitrosodimethylamine (NDMA) and nitrosomorpholine (NMor) with retention times of 1 and 4 days. They used water source samples subjected to simulated drinking water treatment in the laboratory to study(i) prolonged contact time from 1 day to 4 days, (ii) reduction efficiency by conventional treatment, (iii) correlations between DBP formation potentials and water quality parameters, and (iv) the contribution of each species to total risk. With an increased contact time from 1 day to 4 days, THM formation increased to 420% by chloramination. Coagulation-filtration treatment showed that brominated species in THMs are less likely to be reduced.
Chromium in drinking water
WRc has published a thorough and comprehensive report
commissioned by the Drinking Water Inspectorate on the significance of chromium in drinking water. Chromium exists in 3 valency states and of these chromium (VI) has been shown to be carcinogenic. World Health Organization (WHO) has derived a provisional Guideline for Drinking Water Quality (GDWQ) of 50 μg/l for total chromium. and states that separate guideline values for chromium (III) and chromium (VI) should be derived. The study evaluates current toxicological knowledge on chromium (VI) and provides results of a large number of surveys of chromium, chromium (III) and chromium (VI) concentrations in drinking water. In general, concentrations of chromium (VI) found in drinking water in England and Wales are very low, and are consistent with levels reported in other countries (<1μg/l). However one site was the exception to this, where levels of up to 9.94μg/l were reported. The report concludes that in the majority of cases, exposure to chromium (VI) via drinking water in England and Wales is very low and there is no evidence to suggest exposure to the typical concentrations reported in the survey (<1μg/l) will result in adverse human health effects.
Radon in drinking water
DWI has issued Information Letter 05/2015
on Radon in drinking water. The Euratom Directive 2013/51
sets out specific requirements in relation to radon in drinking waters and DWI is in the process of revising the public and private drinking water quality regulations to transpose these requirements.. To inform this revision to the regulations, DWI commissioned a research project to assess the implications for the UK of the Euratom Directive relating to radon in drinking water. The report
includes a map produced of drinking water risk areas for radon with locations of public and private water sources. A key conclusion is that a parametric value for radon of 100 Bq/l is appropriate to adopt to support further investigation, with a concentration of 1,000 Bq/l being set as a value above which remedial action should be taken without further consideration. Advice is given to water companies and local authorities on appropriate monitoring or other actions to be taken based on risk classification.
Novel membrane for desalination
Egyptian workers have developed a new type of membrane capable of a high flux of potable water with over 99.7% salt rejection (%SR) in a once-through purge-air pervaporation (PV) process from a simulated highly saline seawater.
(paper in French
) (English abstract
New Research programmes announced by Government
The Universities and Sciences Minister has announced a number of major research programmes to be co-funded by EPSRC and Industry. They include “Tailored Water Solutions for Positive Impact”
which is to be carried out by a consortium led by Sheffield University. This programme aims to develop solutions to make the UK's aging water infrastructure more resilient to future needs; these include climate change, population increase and interdependencies with other infrastructures (food and energy). They will develop a framework of 'tailored solutions' for the different scenarios through robotics, systems and chemical engineering research amongst others. A key feature of this consortium is the collaboration with the water industry including Thames Water, Northumbrian Water, Scottish and Welsh Water.
Another programme involves a consortium which will develop novel robotics and autonomous systems technologies in a traditional sector such as infrastructure management and repair. The system will be able to sense, diagnose and repair different aspects of infrastructure including utility pipes.
Coagulant recovery and reuse for drinking water treatment
A recent paper studied membrane & chemical purification of recovered water treatment coagulant. Recovered coagulants were assessed with reference to treatment performance. The study concluded
that alkali-stripping coupled with activated carbon polishing performed the best and yielded recovered coagulants which achieved similar contaminant removal to virgin ferric sulfate. Recovered coagulant treated raw water to <2 mg/L TOC, <0.5 mg/L Fe and <0.5 NTU.
UK's largest water recycling system agreed
Cambridge Water has signed an agreement with the University of Cambridge to support the UK’s largest water recycling system at its North West Cambridge Development site. The scheme
will have two water supplies – one which recycles rain and surface water to use for flushing toilets, clothes washing and garden watering, and another supplying high quality treated water for drinking, cooking and bathing. The water recycling system, in conjunction with water efficiency devices and fittings should result in a potable water consumption of 80 litres per person per day, almost half the UK average.
Mercury removal by sulphur-limonene polysulphide
Australian workers at Flinders University are seeking to patent the novel compound sulphur-limonene polysulphide (SLP)
, made by fusing sulphur with limonene. a substance found in citrus fruit peel, The material can absorb toxic mercury from water sources and soil. Once SLP has absorbed the mercury it remains permanently bound to the substance eliminating environmental risks and making the water nearly drinkable, reducing the concentration of mercury in the water by a thousand fold. The substance changes colour when adsorbing mercury and the inventors suggest it could also be used as a detection device in waterways.
OH-BDEs - new contaminants of emerging concern
A recent paper
from a team of researchers led by the university of Minnesota discusses results of measuring hydroxylated polybrominated diphenyl ethers (OH-BDEs) in water and sediment of freshwater and coastal systems along with the anthropogenic wastewater-marker compound triclosan and its photoproduct dioxin, 2,8-dichlorodibenzo-p-dioxin. The production of OH-BDEs occurs naturally from marine bacteria and algae and environmental levels of these chemicals have been increasing over time. Significantly they found no OH-BDEs in their freshwater samples
but water suppliers should be aware of interest in these compounds since they are either equivalent or more potent endocrine disruptors and neurotoxins than the precursor PBDEs.
Nitrogenous disinfection byproducts (NDBP) in English drinking water supply systems.
This recent paper
looks at NDBP occurrence, bromine substitution and analyses correlations. Its main conclusions are -
- Chloramines raised bromine substitution into haloacetonitriles and haloacetamides;
- Bromine substitution was moderately higher in haloacetamides than haloacetonitriles;
- Concentrations of dihaloacetonitriles and dihaloacetamides were well correlated; and
- Halonitromethanes and cyanogen chloride were not correlated with other DBPs.
Waterborne outbreaks in the Nordic countries, 1998 to 2012>
A recent review
refers to 175 waterborne disease outbreaks in Denmark, Finland, Norway and Sweden in the period 1998-2012 ( 2011 for Sweden). 55% of theses were related to municipal or private waterworks. The commonest agents detected were calicivirus and campylobacter. Interestingly there were 6 outbreaks of tularaemia in Norway, caused by Francisella tularensis
. The paper has a wealth of data and analysis of outbreaks It notes that while campylobacter was the commonest cause in the Nordic countries it is only the 3rd commonest behind Shigella
in the USA while protozoal outbreaks appear to be comparatively rare although this could be a reflection of clinical laboratory testing practice.
Water related disease outbreaks - USA 2011-2012
A recent report shows that for 2011–2012, 32 drinking water–associated outbreaks were reported, accounting for at least 431 cases of illness, 102 hospitalizations, and 14 deaths. Legionella
was responsible for 66% of outbreaks and 26% of illnesses, and viruses and non-Legionella
bacteria together accounted for 16% of outbreaks and 53% of illnesses. The two most commonly identified deficiencies leading to drinking water–associated outbreaks were Legionella
in building plumbing systems (66%) and untreated groundwater (13%). The report
has an in-depth analysis of the outbreak data but cautions that the detection and investigation of outbreaks might be incomplete, because linking illness to drinking water is inherently difficult and the level of surveillance and reporting activity, as well as reporting requirements, vary across states and localities.
New Chairman for UK Water Partnership
Lord Chris Smith has stood down as Chairman of the UK Water Partnership after serving for the first 6 months since its inception. His successor is Richard Benyon MP who has served as Parliamentary Under-Secretary of State at DEFRA and has had a long and active interest in water.
Halogenated Nitrogenous Disinfection By-Products
Chinese workers have shown that exposure of some bacteria, primarily Pseudomonas aeruginosa
but also E.coli
, to halogenated Nitrogenous Disinfection By-Products (N-DBP) can significantly increase their resistance to antibiotics, an average increase of 5.5x being shown. The study looked at three currently unregulated NDBP - bromoacetamide, trichloroacetonitrile and tribromonitromethane and 5 different common antibiotics alone and in combination - gentamicin, polymyxin, tetracycline, ciprofloxacin, and rifampin. They say that “Due to the regulation of DBPs, alternative disinfectants — such as chloramine in place of chlorine — have started to be used to reduce quantities of these regulated DBPs. However, these alternatives can produce greater levels of N-DBPs” This research, if replicated, could have regulatory implications. (summary
Contaminants of emerging concern
The US based Water Research Foundation has opened a new Knowledge Portal
for Contaminants of Emerging Concern. The Portal covers endocrine disrupting compounds, pharmaceuticals and personal care products, volatile organic compounds, cyanotoxins, and hexavalent chromium. Other Portals include Disinfection By-products, Distribution System Management, and Microbials (Bacteria, Protozoa and Viruses)
Readability of water quality reports
A recent report has been published on the readability of a representative 30 reports
which water utilities in the USA are required to produce annually. It concludes that the reports were written at the 11th–14th grade level, which is well above the recommended 6th–7th grade level for public health communications. This highlights the importance of pitching water quality reports at the right level for the non-technical reader.
Persuading the public to reduce bottled water consumption
The EC has published a Science for Environment Policy report
in which it states that “It takes on average 3 litres of regular water to produce just 1 litre of bottled water. Based on 2011 consumption rates, that equates to over 100 billion litres of water wasted every year –an important concern given that fresh water is becoming increasingly scarce across the globe. Bottled water production, including packaging, transportation, and refrigeration, also generates CO2, contributing to climate change. Furthermore, the majority of water bottles are not recycled, instead ending up in landfill or littering the natural environment with plastic waste.” It goes on to look at the reasons people buy bottled water and considers strategies to encourage reduction in its consumption.
The report suggests that its findings could help governments to develop persuasive messages to reduce bottled water consumption. The authors recommend campaigns based on the core beliefs that drive bottled water consumption, such as concerns about health, taste and quality. They also say that campaigns that combine information about the environmental impact of bottled water with proof that others of the same social group are changing their behaviour are more likely to be successful than either technique in isolation.
Cyanobacteria blooms and non-alcoholic liver disease
A recent US paper
explores the possible relationship between cyanobacterial blooms and non-alcoholic liver disease. By comparing statistically the incidence of cyanobacterial blooms and significant clusters of non-alcoholic liver disease.
It concludes that at the population level, there is a statistically significant association between the two in the contiguous United States. The risk from non-alcoholic liver disease increased by 0.3% (95% CI, 0.1% to 0.5%) with each 1% increase in bloom coverage in the affected county after adjusting for age, gender, educational level, and race.
New filtration system for efficient recovery of waterborne Cryptosporidium oocysts and Giardia cysts
Danish workers have devloped a reagent-less system
which can be used for monitoring of parasite contamination in drinking water. The system employs a metallic filter, sonication and ‘air backwash’, and achieved an almost 85% recovery of Giardia
and 70% of Cryptosporidium
Statistical models for failure of water distribution pipes
This review paper
looks at 9 different statistical models for predicting pipe failure. For every model an overview of its applications published in scientific journals and the available software implementations is provided. The authors say that the unified view provides guidance to model selection rates.
Fate of geosmin and 2-methylisoborneol in full-scale water treatment plants
A recent Australian study investigates Geosmin and 2-methylisoborneol (MIB)
, which are the main cyanobacterial T&O compounds and can cause complaints from consumers at levels as low as 10 ng/L. The objectives of the study were to:
- estimate the accumulation and breakthrough of geosmin and MIB inside full-scale water treatment plants;
- verify the potential impact of sludge recycling practice on performance of plants; and,
- assess the effectiveness of aged GAC for the removal of these compounds.
Sampling after full-scale treatment processes and GAC pilot assays was conducted to achieve these goals. Geosmin and MIB monitoring in full-scale plants provided the opportunity to rank the performance of studied treatment processes with filtration and granular activated carbon providing the best barriers for removal of total and extracellular compounds, correspondingly. Geosmin was removed to a greater extent than MIB using GAC. Geosmin and MIB residuals in water post GAC contactors after two years of operation was 20% and 40% of initial concentrations, correspondingly. Biological activity on the GAC surface enhanced the removal of T&O compounds. These observations demonstrated that a multi-barrier treatment approach is required to ensure cyanobacteria and their T&O compounds are effectively removed from drinking water.
Taste and odour in source and drinking water. Causes, controls and consequences
IWA will shortly publish this book
, which it describes as providing an updated evaluation of the characterization and management of taste and odour (T&O) in source and drinking waters. Authored by international experts from the IWA Specialist Group on Off-flavours in the Aquatic Environment, the book is said to represent an important resource that synthesizes current knowledge on the origins, mitigation, and management of aquatic T&O problems. The material provides new knowledge for an increasing widespread degradation of source waters and global demand for high quality potable water. Key topics include early warning, detection and source-tracking, chemical, sensory and molecular diagnosis, treatment options for common odorants and minerals, source management, modelling and risk assessment, and future research directions. It includes an updated version of the benchmark Drinking Water Taste and Odour Wheel and a new biological wheel to provide a practical and informative tool for the initial diagnosis of the chemical and biological sources of aquatic T&O. (This reviewer has not read the book and gives no endorsement.
Development and Evaluation of Three Real-Time PCR Assays for Genotyping and Source Tracking Cryptosporidium spp. in Water
A multinational group has developed three real-time PCR genotyping assays, two of which could differentiate common human-pathogenic species (C. parvum
, C. hominis
, and C. meleagridis
), while the other assay was able to differentiate nonpathogenic species (such as C. andersoni
) from human-pathogenic ones commonly found in source water. In sensitivity evaluations, the first 2 assays could detect as few as 1 Cryptosporidium
oocyst per sample. The authors suggest
that the first 2 genotyping assays might be used in environmental monitoring, whereas the third genotyping assay could be useful for genotyping Cryptosporidium spp
. in clinical specimens or wastewater samples.
In-situ tryptophan-like fluorescence: A real-time indicator of faecal contamination in drinking water supplies
A recent study carried out in Zambia
, described as the first study to investigate the use of in-situ tryptophan-like fluorescence (TLF) for the rapid assessment of the biological quality of drinking water supplies. concludes that elevated tryptophan-like fluorescence (TLF) could be a better indicator of pathogens in water sources than thermotolerant coliforms (TTC). It showed that TLF was significantly elevated in supplies where thermotolerant coliforms (TTCs) were present, and was demonstrated to be the most effective indicator of TTC presence/absence. TLF was also the most significant indicator of the number of TTCs. A single-predictor linear regression model using TLF was used to estimate the probability of a water supply belonging to each WHO risk class. This highlights that as TLF concentration increases there is a greater probability of a water supply being within the higher risk groups.
The use of in-situ TLF sensors, which require no reagents and provide instantaneous readings, has advantages over bacterial indicators for inferring the presence of enteric pathogens. TLF is likely to be more mobile and resilient in groundwater and, as such, a more precautionary indicator of enteric pathogens in groundwater, including where bacterial indicators are absent.This could facilitate their inclusion in real-time pollution alert systems for drinking water supplies throughout the world, for the rapid mapping of enteric pathogen risks in developing regions, and as an initial screening tool to inform and complement further water quality investigations.
Drinking water disinfection by-products (DBPs) and human health
A recent review
considers progress since the discovery in 1974 that trihalomethanes (THMs) were formed by the chlorination of natural organic matter (NOM) in drinking water. This discovery revolutionized views on drinking water safety and quality. Since then hundreds of other classes of disinfection by-products (DBPs) have been discovered. The finding in 1976 by the US National Cancer Institute that chloroform, the dominant THM, was a rodent carcinogen spurred a large number of epidemiology and toxicology studies into chlorinated drinking water but in 1985, this cancer finding was shown to be wrong. The reviewers say that w e should now be asking: What do we know about the human health impacts of DBPs in drinking water? Bladder cancer has been the most consistent finding from epidemiologic studies in North America and Europe and the possibility that chlorinated drinking water contributes an increased risk of bladder cancer remains a viable hypothesis. Despite some recent improvements in exposure assessments to focus on inhalation and dermal exposures rather than ingestion, no causal agent with sufficient carcinogenic potency has been identified, nor has a mechanistic model been validated. Consequently, a sensible precautionary approach to managing DBPs remains the only viable option based on four decades of evidence.
U-V and disinfection by-products
A recent DWI report assessing the risk of U-V disinfection leading to by-products of health significance
considers the effect of U-V on the chemical composition of water. It concludes that the potential formation of DBPs as a result of treatment by appropriately designed and maintained UV systems is low. The most significant DBPs are nitrite (formed from nitrate) and bromate (formed from prechlorinated supplies containing bromide); the formation of both can be minimised by appropriate water treatment and UV system design.
Amoebae and pathogens in distribution systems
The US Water Research Foundation in collaboration with the UK Drinking Water Inspectorate has published a study
aiming to improve understanding of the role of amoebae and other free living protozoa (FLP) in the protection and proliferation of pathogens in distribution systems. The report states that FLP almost certainly provide significant
benefits to drinking water by removing/digesting bacteria in biofilms and bulk water. The report includes experimental data on occurrence of FLP and their possible relationship with Mycobacteria and Legionella. It concludes that there is little evidence that FLP can amplify pathogens in water but they may be involved in moving and dispersing pathogens and allowing them to escape imposed stresses such as disinfection. The report also identifies many areas in which more research and information is required.
Microbial Control Strategies for Main Breaks
The UK Drinking Water Inspectorate in collaboration with the US Water Research foundation has published a report of a project to improve utility responses to main breaks and depressurization events to better protect
. The specific project objectives included evaluation of; the effectiveness of disinfection and operational practices to mitigate microbial risks; and identification of parameters to quantify the level of control needed to mitigate the risks of microbial contamination from main breaks and depressurization events.
DWI Annual Report for England 2014
DWI has published its latest Annual Report which compares the position at its inception in 1989 with the position after 25 years. The report is very readable and shows how drinking water quality has improved over the period. It describes the Inspectorate's legal basis and how it carries out its duties and gives some useful statistics about water supply provision in England and Wales. Out of almost 4 million tests only 0.04% failed to meet the required standard in 2014 compared with about 1.6% in 1991. The main area of concern is Private Water Supplies which are relied on by around 1% of the population. In 2014 of the 8054 tests carried out on these supplies 7% failed the test for E.coli
, which demonstrates that faecal matter from birds, animals or humans is gaining access to the water supply and there is a high risk of the supply being associated directly with illness. The report
concludes that there is need for regulatory intervention to mitigate this risk. A similar report is available for Wales
Simultaneous monitoring of faecal indicators and harmful algae using an in-situ autonomous sensor
Researchers in California have developed a fully automated process for monitoring faecal indicators and harmful algae in coastal waters. The process uses an Environmental Sample Processor
coupled with an analytical module known as the microfluidic block
and produces analytical results which are Internet-accessible within hours of sample collection, demonstrating the feasibility of same-day public notification of current water quality conditions. The sensitivity is as yet not sufficient for application to drinking water supplies. (abstract
Hormonal Activity of Bisphenol A Substitutes
Concern over the endocrine disruptive activity of bisphenol A has led manufacturers to use replacements. Some of the replacements are also bisphenol derivatives such as bisphenol S and bisphenol F. A recent review paper
concludes that based on the current literature, BPS and BPF are as hormonally active as BPA, and they have endocrine-disrupting effects. This should be taken into account when considering possible endocrine disrupting compounds in water.
Predicting sources of faecal pollution
A new piece of software
has been developed which uses automatic learning and analysis of various biological indicators to predict faecal pollution in rivers, lakes and reservoirs. The technology still needs considerable development but shows potential.
Removal of natural organic matter in drinking water treatment.
Chinese workers have published a review
which focuses on the methods which are used for removing NOM from drinking water , including coagulation, adsorption, oxidation, membrane, biological treatment processes and the combination of different treatment processes.
Public perceptions of recycled water
A survey commissioned by Thames Water
of visitors to the London 2012 Olympic Park showed a very high level of support for using non-potable recycled blackwater, both in public venues and in homes. This could inform consideration of the role of water reuse in the future of urban water supplies.
USEPA issues Health Advisories for Cyanotoxins
The EPA has issued 10 day Health Advisories for microcysytins and cylindrospermopsin
. These are non-regulatory values which are not enforceable but serve as informal technical guidance to assist federal, state and local officials, and managers of public or community water systems by providing information on the health effects of and methods to sample and treat cyanobacterial toxins in drinking water. However EPA has listed cyanotoxins including microcystin-LR, cylindrospermopsin, and anatoxin–a on the previous and current Contaminant Candidate Lists (CCL), which identify contaminants that may need regulation under the Safe Drinking Water Act. It has not sufficient data at this time to set a Health Advisory for anatoxin A.
Direct potable reuse
The summer 2015 edition of Water Reuse and Desalination
has a number of interesting articles relating to Direct Potable Reuse and overcoming challenges to its adoption. It includes specific detailed examples from India and Saudi Arabia.
Alternative Water Supply Systems
IWA has recently published a useful book
which considers strategies and technologies to alleviate demand on conventional water supplies. The book covers technical, social, financial and institutional aspects associated with decentralized alternative water supply systems. These include systems for greywater recycling, rainwater harvesting, recovery of water through condensation and sewer mining. A number of case studies from the UK, the USA, Australia and the developing world are presented to discuss associated environmental and health implications.
The book provides insights into a range of aspects associated with alternative water supply systems and an evidence base (through case studies) on potential water savings and trade-offs. Although focused on developing countries it includes a number of case studies from the UK, the USA, Australia as well as the developing world and discusses associated environmental and health implications.
Toxicity of a mixture of disinfection by-products (DBPs )
Although a number of conflicting studies have been carried on effect of individual DBPs on rats a recently published study
of the effect of feeding high doses of a mixture of regulated DBPs at up to 2,000 times the US Maximum Contaminant Limits showed no adverse effects on fertility, pregnancy maintenance, prenatal survival, postnatal survival, or birth weights.
Water benchmarking project launched
The UK’s recently launched National Water Benchmarking Project, AquaMark®
, is set to provide over 500 different building benchmark classifications to private and public sector organisations throughout the UK. The ground-breaking scheme claims to be the largest and most ambitious analysis of building water usage to have been undertaken, and expects to help businesses to reduce water usage by an average of 30% and regain up to £500m in lost annual revenue.
India launches the first Microbiological Standard for Water Treatment Devices
In February 2015 the Water Quality India Association (WQIA)
launched the first ever microbiological standards to certify household water treatment devices for consumers in India. These standards have been specifically developed for Indian conditions and match global norms. WQIA also released a Quality Seal that will help consumers choose water treatment devices that meet these standards. WQIA is an industry body of water purifier manufacturers and not an official regulator.
UK Water Partnership
The recently established UK Water Partnership
has held the first meetings of the three Partnership Delivery Groups and Terms of Reference have been set for the groups.
Evaluation and validation of rapid molecular methods for the detection and identification of microorganisms in water - Standard Operating Procedures.
IWA is to publish this book in June 2015
. The book sets out results of a project which reviewed the efficacy of PCR assays for Cryptosporidium
, adenovirus and ammonia oxidising bacteria, as well as candidate techniques for DNA extraction and inhibitor removal. The literature review led to an evaluation of DNA extraction kits and reagents for PCR; finalisation of assay formats; the development of PCR controls and Standard Operating Procedures (SOP); analysis of assay robustness using real samples; and completion of an Inter-laboratory trial using the SOP’s developed.
Innovation in the European Water Sector
Science for Environment Policy has produced Future Brief 10 on Innovation in the European Water Sector
. The interesting brief considers current water challenges and how wastewater treatment innovation and re-use could boost available resources. It also considers barriers to the adoption of innovative approaches and how these might be overcome. Although the Brief is largely focussed on water reclamation it recognises that treated wastewater could ultimately boost drinking water sources.
New Water and Innovation Centre
A new Water and Innovation Centre
has been established by the University of Bath in collaboration with Wessex Water. The centre comprises multidisciplinary research teams, with wide expertise in the natural sciences and engineering, as well as in social, economics and political sciences, in policy, and in business management. Its research is divided into five core themes that tackle the fundamental issues surrounding water: water treatment; water resources; water management; water and public health; and water, environment and infrastructure resilience.
Fluoride and hypothyroidism
Workers at the University of Kent have published a paper
claiming a positive correlation between fluoridated water and hypothyroidism. The publication has provoked criticism from many scientists and health experts who have pointed out that the study design was of low quality and failed to consider other factors which may have differed between the populations being compared.
Private water supplies - disease outbreaks in England and Wales
The Drinking Water Inspectorate has published a review
of the incidence of outbreaks of disease associated with Private Water Supplies between 1970 and 2009. Although the report title refers to the period covered as 1970 to 2009, within which the report identifies 37 outbreaks, the table showing the distribution of outbreaks by year shows 37 outbreaks in the period 1975 to 2011 with the last outbreak being in 2009. The report finds it difficult to draw any firm conclusions but is a useful indication of the scale of health problems associated with Private Water Supplies in England and Wales.
Microbial Removals by a Novel Biofilter Water Treatment System
US workers tested simple gravity fed point-of use treatment units comprised of a carbon filter and foam, using pre-coagulated and settled water. After subsequent passage over a chlorine tablet the process could achieve at least 4 log10 reduction in viruses, 6 log10 for protozoa, and 8 log10 for bacteria). These removal levels met or exceeded Environmental Protection Agency (EPA) standards for microbial purifiers. Exploratory test results suggested that mature biofilm formation within the units contributed 1–2 log10
reductions. The work serves only to prove the feasibility of the method
and does not suggest the technology is ready for use outside the laboratory.
Modification to method for Cl. Perfringens
The Standing Committee of Analysts has published results of a multi-laboratory evaluation of a modified version of the ISO standard medium for Cl.perfringens
followed by a membrane transfer procedure for the acid phosphatase test resulting in confirmed results being available in 18–24 h. This development
significantly reduces the time to confirmed results for Cl. perfringens
from water samples.
New, more efficient membranes
Australian workers have developed new membranes or micro-filters that will result in clean water in a much more energy efficient manner. The new membranes will supply clean water for use in desalination and water purification applications. The membranes have a greater resistance to chlorination products and can cut out additional processing steps reducing operating costs. They can also prevent the decrease in water flow that is currently observed with time due to biological fouling. (Abstract
Managing Cyanobacteria in drinking water.
WHO has published a Technical Brief on Management of Cyanobacteria in Drinking Water Supplies
. It describes a number of measures to prevent the formation of cyanobacterial blooms as well as options to manage such blooms when they occur. Although some of the measures are specific to cyanobacteria, many are equally useful for the management of other hazards. It describes the possible health effects of Cyanobacteria and their role in taste and odour problems. It also outlines factors leading to algal blooms and how they can be managed. A comprehensive and easy to read document which should be invaluable all water supply professionals.
Novel E.coli detection device
The device uses coliphages which when placed in a solution, line up perfectly. However, as soon as E.coli
bacteria are present they separate and tangle allowing light to pass through them. Once the light passes through the sample an electrical signal is generated that is displayed as a set of numbers on a computer screen. The device is being developed
for testing foodstuffs rather than water.
UK Water Partnership launched.
In February 2015 the UK Water Partnership
was launched with the aim of bringing together people across the UK water community to stimulate ideas and develop the products and services that will take on these challenges for the future. The Director of the partnership said “I think we have a great opportunity here to align innovation with growth opportunities both in the UK and internationally. As such, the UK Water Partnership can play an important role in building more sustainable and resilient global networks, while contributing to the economic growth of the UK.”.
WRF introduces new research areas
The US Water Research Foundation has revised its focus areas
, introducing two new focus areas - “Persistent Waterborne Pathogens in Distribution Systems and Premise Plumbing,” and “Defining Attributes and Demonstrating Benefits of Intelligent Distribution Systems.” Three focus areas have been discontinued, these being related to hexavalent chromium, carcinogenic volatile organic compounds, and contaminants of emerging concern. WRF concluded that sufficient progress had been made in these focus areas, while acknowledging that the underlying topics remain very important.
Comparison of methods for E.coli in drinking water.
Canadian workers carried out a comparison of MI agar ( details) and Colilert®, as well as mFC agar combined with an Escherichia coli-specific molecular assay (mFC + E. coli
rtPCR), in terms of their sensitivity, ease of use, time to result and affordability. They concluded that overall, compared with the other two methods tested, the MI agar method offers the most advantages for assessing drinking water quality.
Manganese in drinking water and effects on children
A Canadian study
found that in children, higher levels of exposure to manganese in drinking water were associated with poorer performance of memory, attention and motor functions, but not hyperactivity. These results were found even at low levels commonly encountered in North America. The findings from the present study along with previous results suggest the potential for harmful effects of manganese at levels commonly encountered in groundwater.
New type of membrane for water purification
Research at the University of Twente has evaluated a membrane
which makes it possible to purify water in a single step without the need for preliminary treatment. Compared to existing hollow fibre membranes, with the new membranes it is easier to remove micro-pollutants such as medicine residues, hormones and pesticides from water.
Boil Water Advice – WHO Technical Brief
WHO has issued a Technical Brief
which presents the scientific basis for the efficacy of boiling. The brief confirms the WHO advice that simply bringing water to a rolling boil is sufficient to inactivate microbial pathogens and prolonged boiling is not necessary.
N-nitrosamines, emerging disinfection by-products of health concern
A recent paper gives an overview
of the current knowledge concerning the occurrence, precursors, and formation mechanisms of N-nitrosamines in water. This family of N-DBPs is one of three potential groups of contaminants highlighted in the USA for possible regulatory action in the near future as it is considered that their presence in drinking water may present a more serious risk for humans than regulated disinfection by-products (DBPs) species.
Removal of norovirus from water by coagulation, flocculation and sedimentation processes
Based on jar tests involving a range of viruses, a recent paper concludes that human noroviruses can be appreciably reduced by properly-operated coagulation, flocculation and sedimentation processes and the contamination of drinking water by noroviruses should be controlled by conventional water treatment processes with conventional physico-chemical processes and disinfection. (Abstract
Water purification using a bacterial fuel cell
Researchers in Norway have succeeded in getting bacteria to power a fuel cell using wastewater as fuel. The products of the process are purified water droplets and electricity. This is an environmentally-friendly process which generates small amounts of electricity. In the future, the researchers hope to scale up this energy generation to enable the same energy to be used to power the water purification process.
Nano-material coated sponges for water purification
A low cost, low energy method to disinfect water using electricity has been developed by researchers by combining carbon nanotubes and silver nano-wires with polyurethane sponge. The technology has the potential to be used in portable disinfection devices in developing countries. (Details
Does Global Progress on Sanitation Really Lag behind Water?
Current benchmarks for access to water and sanitation, established by the WHO/UNICEF Joint Monitoring Programme for Water Supply and Sanitation (JMP), treat water and sanitation differently, masking deficits in household water access. Sanitation needs to be at household level to be considered improved whereas water need only be at community level. Using these benchmarks it is considered that there is a greater need for more improved sanitation than for water. A new study conducted jointly by The Water Institute at the University of North Carolina at Chapel Hill and the London School of Hygiene & Tropical Medicine shows that when both are assessed at household level then the global deficit is as great for water as sanitation. The report
calls for a new global standard for improvements in household drinking water and sanitation access.
Scilly Isles proposed changes to water and sewerage regulation
Although the Scilly Isles have been able to partly opt out of Water and Wastewater Regulations and the Drinking Water Inspectorate has no powers in the Isles, Defra has determined that this should no longer apply and has started a consultation process.(consultation document
) Although it has been indicated that £2m might be provided to assist with costs of this change the Council of the Isles is concerned that this would be seriously inadequate. (council letter
). Defra recognises that partial or full privatisation of services may be required.
WHO Guidelines proposed revision – Silver
WHO invites comments by February 27th 2015 on a number of draft Guideline revision proposals including silver.
Fracking ban in groundwater protection zones proposed.
Tom Greatrex ( Labour) has tabled an amendment
to the Infrastructure Bill on 6 January 2015 which proposes fracking be prohibited in designated groundwater protection zones.
Advances in Water Research
The latest issue of Advances in Water Research
published in the US by the Water Research Foundation contains articles on Emerging Pathogens, Emerging Contaminants, Hexavalent Chromium Treatment and Localised Control of DBPs. It also includes statistics of Waterborne Disease Outbreaks in the US from 1971 to 2008.
World Water Congress Report 2014
No disruption pipe repair
A newly published UKWIR project report
reviews the comparative benefits and disadvantages of ‘no disruption’ pipe repair methods against those of traditional repair methods. It assesses whether the choice of repair method affects the risk of network failure in the short-, medium- and long-term.
The Drinking Water Inspectorate has issued Information Letter
04/14 updating its data reporting requirements for Cryptosporidium
monitoring in drinking water supplies from 1 January 2015, with particular reference to monitoring and reporting raw water sources.
Bacterial biothreat agents inactivation
A recent paper in the Journal of Water and Health presents a review of research relevant to disinfection of bacteria with the potential to pose a severe threat to public health and safety, and their potential surrogates. The efficacy of chlorine, monochloramine, chlorine dioxide, and ultraviolet light to inactivate each organism in suspension is described. The complexities of disinfection under varying water conditions and when the organisms are associated with biofilms in distribution systems are discussed.
Simultaneous quantification of multiple viruses in environmental water samples
Japanese workers have developed a quantitative PCR procedure
for simultaneously enumerating 11 different human viral pathogens in environmental water saamples.
Best Practice Guide Control of Arsenic in drinking water
This Best Practice Guide on the Control of Arsenic in Drinking Water
is published by IWA. It arises from the knowledge collected by the European Research Network COST Action 637 involving 27 European countries and the USA. Besides the large number of important papers, reports and reviews already available on various aspects of arsenic occurrence in environment, water and food and related human exposure, this book fills a gap in the field concerning assessment of risks, implications, challenges, and actions required by public health managers.
Water Loss Control
The July-September issue of Advances in Water Research includes an article advocating pro-active leakage management and includes links to recent Water Research Foundation and other publications relating to water loss
. The article refers to a project to help the design of leakage control programmes
which produced an analysis tool
for leakage component analysis.
Water Supply Reservoir Management
Treatment of Cyanobacteria and toxins
The recent issue of Advances in Water Research carries an article based on a Water Research Foundation project on “Optimising Treatment for the Removal of Cyanobacteria and Toxins
” due for publication in 2015(article). The article makes many points including that pre-chlorination should not be used when blooms occur and also that turbidity cannot be used as a surrogate for presence of cyanobacteria.
Future revision of WHO Guidelines on Drinking Water Quality.
Preparation is well under way for the proposed revision in 2020 of the WHO Guidelines. The report of meetings held in Singapore
in June 2014 to progress the revision are now available. The meetings held over 2 days covered a remarkable amount of detail and the 68 page report is a mineof information. Areas considp://ered included potable re-use; alternative disinfectants; and microbial aspects.
UKWIR has published results of a study
which identifies successful ways of engaging with water customers who are at risk of exceeding the standard for lead in drinking water and encouraging them to replace their lead supply pipes. It also provides estimates of the number of customers likely to replace their lead pipes assuming different interventions, and hence determines the overall effectiveness of potential lead replacement programmes.
Establishing a Robust Case for Final Effluent Reuse - An Evidence Base
Water stress and environmental regulations in the UK are driving UK water companies to consider reuse as a strategic supply option and so require evidence on the array of risks and opportunities this brings. This recent UKWIR publication
examines evidence from over 200 relevant case studies of both successful and abandoned treated effluent reuse projects. Real (and perceived) risks associated with different reuse scenarios are identified considering their applicability in the UK.
Public acceptability of indirect potable water reuse in the south-east of England
In anticipation of a projected shortfall in water supply in the South East by 2020 Thames Water is investigating indirect potable reuse as a potential new supply option. 2,000 Thames Water customers participated in an on-line survey
of their attitudes to indirect potable reuse which showed overall support for the idea of indirect potable reuse.
Perchlorate in drinking water and IQ.
A recent paper in the Journal of Clinical Endocrinology and Metabolism
describing a study of pregnant women with borderline thyroid function showed that exposure to high end perchlorate levels in the first trimester was associated with lower IQ in the children. Some US States already regulate perchlorate in drinking water and USEPA intends to set a standard.
Tetrachloroethylene (TCE) and stillbirth
A recent paper in the journal Environmental Health
looked retrospectively at pregnancies in 1766 women in New England and concluded that there may be some association between TCE exposure and stillbirth, with mothers exposed to higher than the median level of TCE having a 2.38 times risk of stillbirth at 27 weeks gestation or later.
Water Fluoridation and IQ
Groups in New Zealand opposed to fluoridation of drinking water have recently cited poorly designed studies based on very high fluoride levels. Results have been published of a 38 year cohort study
carried out in New Zealand. After adjusting for potential confounding variables, including sex, socioeconomic status, breastfeeding, and birth weight (as well as educational attainment for adult IQ outcomes), the study showed no association between fluoride and IQ.
Water Distribution System Deficiencies and Gastro-Intestinal Illness (GII)
Workers in California have published results of a meta-analysis of published literature on distribution system deficiencies and GII
. They reviewed published studies that compared direct tap water consumption to consumption of tap water re-treated at the point of use (POU) and studies of specific system deficiencies such as breach of physical or hydraulic pipe integrity and lack of disinfectant residual. Despite significant deficiencies in many studies and a publication bias in favour of studies showing positive associations they concluded that tap water consumption is associated with GII in malfunctioning distribution networks. System deficiencies such as water outages also are associated with increased GII, suggesting a potential health risk for consumers served by piped water networks.
DWI Research Newsletter September 2014
DWI has published its latest Research Newsletter Issue 9
. Completed Projects described are:-
Research Newsletter Issue 8
- Assessing the likelihood of selected veterinary medicines reaching drinking water;
- Speciation of manganese in drinking water;
- Health risk reductions;
- On-line monitor performance;
- Risks from personal care products and domestic cleaning products;
- Toxicological evaluation for pharmaceuticals in drinking water;
- Raw water monitoring data;
- Viruses in raw and partially treated water;
- Enhancing the value of molecular methods to the water industry; and
- Brass fittings – a source of lead in drinking water?
- Monitoring of Nitrogenated DBPs in drinking water;
- Understanding the changes in pesticide usage to inform water company risk assessments;
- Health-based targets for drinking water safety and regulation ;
- Probabilistic modelling for assessment of exposure via drinking water ; and
- Potential contaminants in drinking water treatment chemicals.
Environmental safety of common surfactants
has recently been published of over 250 published and unpublished studies concerning the environmental preperties, fate, and toxicity of the four major classes of surfactant used in personal care and cleaning products. The exceptionally comprehensive review, promoted by the American Cleaning Institute, deals at length with their structures, mode of action, usage, toxicity, and biodegradability. The review concludes that the surfactants present no risk to aquatic or sediment environments but does not consider implications for drinking water abstractions.
Mineral coating in rapid sand filters:
Danish workers have published research
showing that contrary to common belief, mineral coating developing in rapid sand filters improves their performance, particlarly in ammonia removal. Mineralisation is associated with increased microbial populations. This suggests that excessive back-washing can be counter-productive.
Fracking and groundwater
Performance Indicators for Water Supply Services
In August 2015 IWA published the third edition
of its widely used performance indicator system, which represents a further improvement of the original manual. It contains a reviewed and consolidated version of the indicators, resulting from the real needs of water companies worldwide that were expressed during the extensive field testing of the original system. The
indicators now properly cover bulk distribution and the needs of developing countries, and all definitions have been thoroughly revised. The confidence grading scheme has been simplified and the procedure to assess the results- uncertainty has been significantly enhanced. In addition to the updated contents of the original edition, a large part of the manual is now devoted to the practical application of the system.
Personal care and domestic cleaning products – risk to water supplies
WRc published a DWI funded report in June 2014
on “ Risks to Drinking Water from Personal Care Products and Domestic Cleaning Products”. Of the 692 chemicals that are commonly used in PCPs and DCPs which were screened to develop a shortlist of chemicals that were identified as
having a higher potential to occur in drinking water 33 were identified as of potential importance. However, ten of the 33 prioritised chemicals were predicted to produce levels of maximum exposure through drinking water and bathing close to or greater than would be anticipated through their intended use. The Report suggests targeted monitoring for these and also toxicological assessments.
Evidence Review of Catchment Strategies for Managing Metaldehyde
UKWIR has published a review
which summarises the current extent and severity of metaldehyde non-compliance in the UK and the water industry's response to it. It collates data on the costs of implementing catchment management initiatives; reviews the effectiveness of catchment management and abstraction management in limiting metaldeyde concentrations in drinking water; and highlights key evidence gaps and examples of best practice.
Disinfection by-product occurrence in selected European waters
A European survey of regulated and emerging disinfection by-products (DBPs) in drinking waters in selected regions that were part of epidemiology studies showed that the levels of DBPs found reflected the diverse regions from which the samples were collected, the different treatment/disinfection processes and the different source waters. In addition to a wide range of concentrations of DBPs (e.g. median trihalomethanes (THMs) of 8–85 μg L–1), bromine incorporation was quite diverse (e.g. some waters were highly dominated by bromine-containing DBPs, whereas others only had chlorine-containing species). Bromine incorporation was highest in the haloacetonitriles (HANs) and was lowest in the trihalogenated haloacetic acids (THAAs). In addition, the ratios of THMs to HAAs, THMs to HANs, and THAAs to dihalogenated HAAs varied. Heauthors conclude that exposure assessment based on THMs alone was not sufficient for indicating the presence of emerging DBPs of health concern. Occurrence studies must include a more diverse group of analytes to better understand exposure to DBPs of health concern.
Ensuring Safe Drinking Water: Learning from Frontline Experience with Contamination
A recent AWWA publication
presents 21 case studies—10 waterborne disease outbreaks, 7 cases of severe chemical contamination, and 4 close calls—written largely from the perspective of frontline personnel who experienced the events as they unfolded. An aid to learning from past failures.
A decade with nucleic acid-based microbiological methods in safety control of foods
Water being the universal foodstuff, this recent paper
in Letters in Applied Microbiology should be of interest to anyone looking to develop novel approaches to drinking water microbiology.
Local Authority Water Stewardship
A report published
by the Association for Public Service Excellence (APSE), demonstrates how councils can be effective local water stewards. The report focusses on local authority planning for, and response to, extreme weather events.
Worldwide water shortage predicted by 2040
Two new reports that focus on the global electricity water nexus
have just been published. Three years of research show that by the year 2040 there will not be enough water in the world to quench the thirst of the world population and keep the current energy and power solutions going if we continue doing what we are doing today. Combining new research results with projections about water shortage and the world population, by 2020 many areas of the world will no longer have access to clean drinking water. The results predict that by 2020 about 30-40% of the world will have water scarcity, and according to the researchers, climate change can make this even worse.
Arsenic removal adsorbant regeneration
A process for regeneration of adsorbtive medium used to remove arsenic has been developed. The regenerated medium shows no loss or degradation. The first (and only) full-scale deployment is saving the participating utility $20,000 to $30,000 per year. The savings are gained by backwashing and regenerating, rather than repurchasing, iron-based adsorptive media.
Disinfection by-product occurrence in selected European waters
A European survey
of regulated and emerging disinfection by-products (DBPs) in drinking waters in selected regions that were part of epidemiology studies showed that the levels of DBPs found reflected the diverse regions from which the samples were collected, the different treatment/disinfection processes and the different source waters. In addition to a wide range of concentrations of DBPs (e.g. median trihalomethanes (THMs) of 8–85 μg L–1), bromine incorporation was quite diverse (e.g. some waters were highly dominated by bromine-containing DBPs, whereas others only had chlorine-containing species). Bromine incorporation was highest in the haloacetonitriles (HANs) and was lowest in the trihalogenated haloacetic acids (THAAs). In addition, the ratios of THMs to HAAs, THMs to HANs, and THAAs to dihalogenated HAAs varied. Heauthors conclude that exposure assessment based on THMs alone was not sufficient for indicating the presence of emerging DBPs of health concern. Occurrence studies must include a more diverse group of analytes to better understand exposure to DBPs of health concern.
Molecular methods in the Water Industry
A recent paper in Advances in Water Research, the US Water Research Foundation Journal, discusses the potential for use of molecular methods in the microbiological analysis of water samples. The adoption of molecular methods is constrained by the use of culture-based methods in standards although the adoption by the EPA of a qPCR method for enterococci in recreational waters is encouraging. A combination of short duration culture followed by qPCR shows promise but needs further development.
Private Water Supplies – DWI website
DWI has added a section on Private Water Supplies(PWS) to its website. The section
gives advice to owners and users of PWS as well as installers and suppliers of PWS equipment. It also gives advice to Local Authorities in respect of their PWS duties.
Molecular Method for Detection of Total Coliforms in Drinking Water Samples
Canadian workers showed that using 3 different PCR assays they could detect total coliforms in at least as many samples as with cultural methods. The 16S rRNA molecular assay on its own was shown to be as efficient as recommended culture-based methods. They say that the assay might be used in combination with an Escherichia coli molecular assay to assess drinking water quality. (Abstract
Draft report on regulations and standards for drinking - water quality
WHO has released this draft report
for comment by July 25th 2014. The report documents the values specified in national standards for drinking-water parameters and how they compare to those set out in the fourth edition of the WHO Guidelines for Drinking-water Quality.
Water Safety in Distribution Systems
WHO has recently published a reference tool to help water suppliers and regulators who are familiar with the Water Safety Plan approach, enhance their risk assessment and management and investment planning for their water distribution systems. (Full text
Fouling of membrane filters – reduction by biofiltration
Continuing work in Canada using two pilot-scale dual media (sand/anthracite) filters confirmed that the parallel biofilters performed similarly with both averaging on 21% biopolymer removal. Raw and treated water biopolymer concentrations were correlated, with increased absolute removals occurring at higher raw water concentrations. Ultrafiltration (UF) membrane fouling experiments showed substantial improvement in performance following biofiltration pretreatment by reducing hydraulically irreversible and reversible fouling rates by 14–68% and 8–55%, respectively. The results also reaffirm the importance of biopolymers at concentrations as low as ∼0.1 mg/L on irreversible and reversible UF membrane fouling and a minimal impact of humic substances. (Abstract
Arsenic removal from groundwater using electrolytic iron dissolution
Danish workers are developing a method for arsenic removal based on electrolytic iron dissolution and efficient aeration prior to sand filtration. The treatment was investigated in a pilot scale plant and full scale waterworks. The pilot scale results showed the potential for efficient arsenic removal from spiked solutions (with As in the range of 50–85 μg/L) depending on the process conditions (flow and applied current). In the waterworks where the system was implemented for a period of 14 months, there was a relationship where the higher applied current from the iron generator resulted in a better quality of water produced. The electrolytic dissolution of the Fe was found to be a practical method for iron dosing; however more work has to be done on process improvement and optimization.
New methods for faecal source tracking
Norwegian workers have developed a system using cultural detection of E.coli
followed by molecular methods to detect host-specific markers associated with humans or animals. The method can also be used with additional marker sets to identify the presence of STEC (Shiga Toxin producing E.coli
Water and Cities
UKWRIP has published a report of a workshop which mapped out current research investments in water and cities, and identified a number of opportunities to improve the UK’s approach to water and cities. The report
includes a spreadsheet of over 130 current relevant initiatives. Although there is little relevant to public water supplies in the UK it is nonetheless a useful compendium.
Water Act 2014
The new Water Act received Royal Assent on May 14th 2014. The Act is wide-ranging and covers Water Supply and Sewerage licencing, and introduces a requirement to ensure resilience. It also includes sections on Water Resources, Environmental Regulation, and Flood Insurance
(Water Act 2014
Faecal Contamination of Drinking-Water in Low- and Middle-Income Countries
A meta-analysis of 319 published studies showed that while water from improved sources is less likely to contain faecal contamination than unimproved sources, they are not consistently safe. This study also provides evidence that by equating “improved” with “safe,” the number of people with access to a safe water source has been greatly overstated, and suggests that a large number and proportion of the world's population use unsafe water (paper
1,4 dioxane and drinking water
The US Water Research Foundation has published a detailed review of 1,4 dioxane
and its implications for drinking water supplies.
RCUK opens Gateway to Publicly Funded Research
has been developed by the Research Councils UK (RCUK) to enable users to search and analyse information about publicly funded research. The website shows data from all seven research councils and the Technology Strategy Board. It enables easy access to information about current research projects and outcomes of past projects and will be of interest to users such as academic institutions and the general public. The site is comprehensive,easy to use and provides access to a large number of related research projects.
The STREAM programme is delivered by five UK academic centres of excellence in water science and engineering in the UK. Coordinated by Cranfield University and including Imperial College London and the universities of Sheffield, Newcastle, and Exeter, the programme is funded by the Engineering and Physical Sciences Research Council (EPSRC) and companies who sponsor research projects. The website gives details of funded new projects available to post graduates.
Magnesium in drinking water and heart disease
Studies in many countries have demonstrated a relationship between drinking water mineral content and the risk of death in cardiovascular disease (CVD), particularly for magnesium and it has been suggested that magnesium be added to drinking water. The article evaluates the validity of this suggestion by reviewing information on possible causative agents. Major epidemiological studies on the drinking water content of calcium, magnesium, and hardness were analysed regarding exposure specificity, confounding factors, dose-response relationships and biological plausibility. Intervention experiments were analysed. The risk of death in CVD was related to the content of Ca, Mg and HCO3−. The data demonstrate that Ca and Mg need to be considered together, and that HCO3− could play a role by intervening with the body acid load. There is no evidence to justify the addition of magnesium only to drinking water for preventive purposes. The data suggest that Ca and Mg could be administered together but no data are available regarding the relative proportions for an optimal effect.
New Zealand drinking water quality
The New Zealand Ministry of Health report for 2012-2103 shows that compliance with all drinking-water standards increased by 0.2 percent to 76.9 percent in population terms during 2012/13, bacterial compliance was 96.7 percent and chemical compliance was 95.3 percent. These bacterial and chemical compliance rates are also across all water supplies serving over 100 people, including small drinking-water supplies which generally experience greater difficulty in achieving compliance. However large supplies only achieved 99.0% compliance for bacterial standards and 97.1% for chemical standards. There was a slight decrease in protozoal compliance, from 79.8 to 79.2 percent. There is clearly a long way to go before drinking water in New Zealand reaches the quality enjoyed in England and Wales. (Summary
Factors affecting cryptosporidium oocyst recovery
A Water Research Foundation funded study
found a set of likely causes of poor Cryptosporidium
oocyst recovery in Portland Water Bureau source water from the Bull Run watershed at certain times of the year. The report presents a modification to EPA Method 1623 that improved oocyst recovery for Portland Water Bureau, and this research contributes to an improved understanding of the role that water matrices play in inhibiting oocyst recovery.
Temperature tolerances for microbial drinking water testing with enzyme substrate tests
Researchers at Bristol University have shown that recovery of chlorine-injured E. coli
in Colilert was not impaired within the range 33–39 °C; the equivalent range in Aquatest medium was 31–43 °C. Both these tests recovered E. coli
without significant loss of performance over a wider range of temperatures than currently specified. This is important for drinking water testing where laboratory resources are limited. (Abstract
Waterborne outbreak of cryptosporidiosis due to Cryptosporidium cuniculus (formerly rabbit genotype)
A waterborne outbreak of cryptosporidiosis
in Northamptonshire is the first waterborne outbreak shown to be due to C. cuniculus
, a species previously not thought to be a human pathogen. Unusually no children under five were infected in the outbreak, which may have involved over 400 cases of which 23 were shown by laboratory testing to be microbiologically linked to C.cuniculus
Implications of Microbial Colonisation of Water in Buildings
UKWIR has recently published a report (ref. 13/DW/02/67) which aims to provide water companies with an informed assessment of the current knowledge and understanding of the origin and behaviour of the organisms of potential health significance in plumbing systems.
Disinfection By-Product Risk Assessment: DBPs of Concern
The large number of known DBPs makes measurement impractical, if not impossible. UKWIR has just published a report (14/TX/05/2) which developes a pragmatic risk-based approach to identify potential DBPs, based on knowledge of factors which lead to their formation and mitigation. DBPs have been categorised according to their chemical structures and the potential risks for these categories, based on toxicity, likely occurrence and concentration. The approach has been encapsulated in a spreadsheet-based risk assessment tool that enables the potential formation of DBPs at treatment works to be quickly assessed, and the works to be ranked according to the risk.
Simple water filtration technique for individual use.
Workers supported by Massachusetts Institute of Technology have demonstrated that the pores in plant xylem are capable of retaining bacteria
. Passing water through intact sapwood from white pine sealed in PVC tube can remove over 99.9% of bacteria. The technique requires development but may need no external energy source and has potential for use in developing countries and for emergency supplies in the field.
Mycobacteria in drinking water
For many years workers have speculated on the role of drinking water in the transmission of the Mycobacterium avium
complex (MAC) with no definitive conclusions. A recent Australian PhD thesis addressing the occurrence of MAC in Brisbane's water supplies concluded that strains of MAC found in water supplies were also found in cases of disease in the community. The Author's suggestions regarding the need to boil drinking water for 4 minutes may be considered alarmist
Metaldehyde – DWI letter
DWI has issued an Information Letter
to update companies on the outcome of the Inspectorate’s assessment of companies’ PR14 submissions for metaldehyde and to set out its position regarding the appropriateness of current legal instruments for metaldehyde and other pesticides.
Alternative to PCR
Irish Water likely to be over-staffed
Established in March 2013 as a semi-state company under the Water Services Act 2013, Irish Water will bring the water and wastewater services of the 34 Local Authorities together under one national service provider. (Company Website
Irish Water is gradually taking over the responsibilities from these Local Authorities on a phased basis from January 2014. It will take approximately five years for Irish Water to be fully established, at which point it will be responsible for the operation of public water services including management of national water assets, maintenance of the water system, investment and planning, managing capital projects and customer care and billing. An expert has warned that the new Company will inherit 4000 employees but will only need 1700.(Report)
Wessex signs water resilience deal with Sembcorp Bournemouth
Wessex Water has signed a water resilience agreement with Sembcorp Bournemouth Water to ensure that if a problem occurs on either network, a backup supply would be available to avoid any impact on customers. A small water plant will be constructed at the regional border to facilitate the bulk transfer of water.
DWI Research Newsletter
DWI has published its annual Research Newsletter
. Completed Projects described are
- Monitoring of Nitrogenated DBPs in drinking water;
- Understanding the changes in pesticide usage to inform water company risk assessments;
- Health-based targets for drinking water safety and regulation ;
- Probabilistic modelling for assessment of exposure via drinking water ; and
- Potential contaminants in drinking water treatment chemicals.
WRc 2014 Portfolio
WRc has published details of the research projects in its 2014 Portfolio
Updated Legionella Code of Practice
HSE has published the fourth edition of “Legionnaires' disease. The control of legionella bacteria in water systems - Approved Code of Practice and guidance”
The book is aimed at dutyholders, including employers, those in control of premises and those with health and safety responsibilities for others, to help them comply with their legal duties in relation to legionella. These include identifying and assessing sources of risk, preparing a scheme to prevent or control risk, implementing, managing and monitoring precautions, keeping records of precautions and appointing a manager to be responsible for others.
Hospital water taps contaminated with bacteria
Italian workers have shown a high level of contamination of hospital tap aerators by various species of gram-negative opportunists. A useful critique in the same journal suggests caution when interpreting the health significance of the study.(Paper
Lab on a Chip gives rapid results
Engineers from the A*STAR Institute of Materials Research and Engineering and colleagues at the University of Basel, Switzerland, have designed and developed a compact, portable analytical instrument that can detect multiple ions and molecules down to a level of 300 parts per billion (ppb) in less than a minute. The device is not yet commercially available.
The machine, based on lab-on-a-chip technology, needs only drop-sized liquid samples. The analysis is very quick, precise and sensitive, and can be performed remotely as no direct contact with the solution is necessary. The paper reports analysis of six cations (NH4+
) with a detection limit of approximately 5 μM and the analysis of the anions (Br-
, F -
) with a detection limit of about 3 μM. The device is considered to have potential applications in the water, food and beverage, agriculture, environmental, pharmaceutical and medical industries. (Summary
Cryptosporidium literature review
IWA has just published a review of the literature on Cryptosporidium which helps to identify the findings and formulates the key research questions. It covers these central questions:
- What are the sources/carriers of human pathogenic strains and what are the key species for a range of catchments?
- What is the contribution of pre and post weaned cattle and sheep to catchment contamination?
- What data on animal management practices (including vegetation management of riparian zones) is available?
- What are the different climatic zones across catchments and how will this impact on the survival and transmission of Cryptosporidium?
UNDERSTANDING THE POTENTIAL IMPACTS OF SHALE GAS FRACKING ON THE UK WATER INDUSTRY
This UKWIR report represents Stage 1 of a project to understand the potential impacts of fracking on the UK water industry. It is an 81-page document presenting an assessment of:
- The location of potential shale gas reserves in the UK;
- The relationship between shale gas reserves and water resources;
- The relationship between shale gas reserves and water company infrastructure; and
- The likely location, scale and timing of water demand
The principal benefit of the work reported here to the UK water industry is that it provides an increased knowledge and understanding of risks to water resources in terms of the likely scale, location and duration of water demand from shale gas operations ISBN1 84057 699 5 (Report
RCUK opens Gateway to Publicly Funded Research
Gateway to Research (GtR) website has been developed by the Research Councils UK (RCUK) to enable users to search and analyse information about publicly funded research. It includes data from all seven research councils and the Technology Strategy Board. The website enables easy access to information about current research projects and outcomes of past projects and will be of interest to users such as academic institutions and the general public. The site is comprehensive,easy to use and provides access to a large number of water related research projects (gateway
Norovirus detection in water using PCR
French workers have developed a method for detecting norovirus in water based on viral concentration by filtration on electropositive filters and direct lysis of adsorbed viruses from filters before RNA extraction and RT-qPCR amplification. They then use a one-step multiplex RT-qPCR assay developed for the simultaneous detection of NoV GI, NoV GII and MNV-1( murine norovirus). Water samples were artificially contaminated to determine mean virus recoveries and method sensitivity. The method showed a higher sensitivity for detecting NoV GII (103 genome copies per 0·5 l) than for NoV GI (104 genome copies per 0·5 l) in the presence of MNV-1 regardless of the type of water. The data also showed that MNV-1 is a robust option as a process control. The method described provides a valuable tool for the monitoring of potential public health risks associated with NoV contamination in potable water. (Abstract
Salmonella in biofilms
Lab scale investigations into the ability of Salmonella to form biofilms in monoculture and the fate and persistence of Salmonella in a mixed aquatic biofilm were carried out. In monoculture S. typhimurium
formed loosely structured biofilms. Salmonella colonized established multi-species drinking water biofilms within 24 hours, forming micro-colonies within the biofilm. S. typhimurium
was also released at high levels from the drinking water-associated biofilm into the water passing through the system. This indicated that Salmonella could enter into, survive and grow within, and be released from a drinking water biofilm. The ability of Salmonella to survive and persist in a drinking water biofilm, and be released at high levels into the flow for recolonization elsewhere, indicates the potential for a persistent health risk to consumers once a network becomes contaminated with this bacterium. (Abstract
BisphenolA (BPA) more harmful than thought.
In 2007, a group of experts critically analyzed hundreds of publications on bisphenol A (BPA), including the evidence for low dose effects. An update of these evaluations concludes that several dozen "low dose" studies show effects of BPA at doses that humans are thought to encounter in their everyday lives. It concludes that the doses that reliably produce effects in animals are 1–4 magnitudes of order lower than the current LOAEL of 50 mg/kg/day and many should be considered adverse. With the knowledge that such tiny amounts of BPA can have such far-reaching implications for humans and wildlife, stricter regulations of this chemical and other endocrine disruptors should be fast on its heels. (Abstract
The update details the effects of BPA exposure both in vitro and in vivo, and how it contributes to a large range of health problems in humans, such as polycystic ovarian syndrome, immune response to allergens, behavioral problems and decreased fertility. The effects on wildlife are also widespread.
A real-time PCR assay for detection of Cl. perfringens in water
Canadian workers have compared a concentration and recovery procedure coupled with real-time PCR assay (CRENAME) to detect Cl. perfringens
in drinking water with a conventional culture method. CRENAME could detect 1 Cl. perfringens
in 100ml in less than 5 hours whereas the cultural procedure required at least 25hrs and it could also be developed to allow detection of E.coli
in the same sample.
New ISO standard method for coliforms and E.coli
The international standard for the detection and enumeration of E. coli
and coliform bacteria in drinking water by membrane filtration (ISO 9308-1) is currently under revision and will be published in 2014. In the new standard, lactose–triphenyl tetrazolium chloride (TTC) agar will be replaced by chromogenic coliform agar (CCA) which relies on detection of β-D-galactosidase and β-D-glucuronidase. A performance validation of the revised method according to ENV ISO 13843 was carried out to determine fundamental data on its applicability and to provide reference data for secondary validation by users of this method. Although the robustness of the method with respect to the variable incubation time of 21 ± 3 h was found to be low, because an incidental increase in presumptive colonies especially between 18 and 21 h was observed, the report concludes that the CCA method was proved as a reliable method for the quantification of E. coli
and coliform bacteria. (Abstract
Glyphosate degradation and removal in water treatment
Workers at WRc have published a review of the reported efficiency in removal and degradation of glyphosate and aminomethylphosphonic acid (AMPA) by some commonly employed treatment options, and carried out additional experiments where knowledge gaps have been identified. Although of low toxicity, the presence ofglyphosate in drinking water is undesirable and can cause drinking water compliance failure in the EU if found at concentrations >0.1 μg L-1
. Oxidants used in water treatment, particularly Cl2
, are highly effective in degrading glyphosate and AMPA but removal by coagulation and activated carbon is ineffective as a barrier against contamination in drinking water. UV treatment is also ineffective for glyphosate and AMPA degradation but the combination of UV/H2
provided significant degradation of glyphosate, but not AMPA, under the conditions investigated. UV/TiO2
treatment can degrade significant amounts of glyphosate but the irradiation time needed is long. Removal or degradation by bank filtration, slow sand filtration, ClO2
and membranes is variable but can provide significant removal under the right conditions. (Details
Pathogenic amoebae in tap water
US workers investigated the deaths from Naegleria fowleri
infection of 2 children in Arizona with no history of swimming in surface waters. Using nested PCR they detected the pathogenic amoeba in several samples from the domestic water supply in the houses of both children. The supply was by a private Company from a well or holding tank depending on demand and was not filtered or disinfected. The paper includes a useful review of water supply related Naegleria fowleri cases.
causes infection only via the nasal passages and not through ingestion.
Interventions to improve water quality for preventing diarrhoea
A recently published review examined trials of interventions to improve the microbiological quality of drinking water and reduced incidence of diarrhoea. These include conventional improvements at the water source (eg protected wells, bore holes, and stand posts) and point-of-use interventions at the household level (eg chlorination, filtration, solar disinfection, and combined flocculation and disinfection). The review covered 38 independent comparisons from 30 trials that involved more than 53,000 people. In general, such interventions were effective in reducing episodes of diarrhoea. Household interventions were more effective in preventing diarrhoea than those at the source. However, differences in the interventions and the settings in which they were introduced, as well as the methods and measurements of effect, limit the extent to which generalizations can be made. Further research, including blinded trials and longer-term assessments, is necessary to understand the full impact of these interventions.
The latest edition of the UKWIR Newsletter is now available. It describes a number of recent activities and lists all projects let since April 2012, with the appointed contractors.
Priority Substances Directive amendment
An amendment to “Directives 2000/60/EC and 2008/105/EC as regards priority substances in the field of
water policy” was published on 12 August 2013 as Directive 2013/39/EU.
Direct potable re-use of reclaimed water.
The US Water Research Foundation
in conjunction with six California water supply companies is sponsoring two research projects into the direct potable re-use of reclaimed water. Proposals are to be invited for the two projects: Assessment of Techniques for Evaluating and Demonstrating Safety of Direct Potable Reuse Product Water ($275K); Blending Requirements for Water from Direct Potable Reuse Treatment Facilities ($325K).
Norovirus inactivation on copper.
Workers at Southampton University have shown that norovirus is rapidly inactivated on dry copper and copper alloy surfaces, the rate of inactivation being proportional to copper content. Inactivation on copper/nickel alloys was very effective. They suggest that the use of copper surface could help reduce the spread of the virus in high-risk situations such as cruise ships and care homes. (It is not suggested that the use of copper plumbing provides any virucidal benefits
US requires tamper-proof packaging of water treatment chemicals.
The NSF Joint Committee on Drinking Water Treatment Chemicals and the NSF Council of Public Health Consultants (CPHC) have adopted new tamper-evident requirements for packaging of drinking water treatment chemicals. Similar requirements are already in AWWAstandards. (Details
Responsibility for water supply pipes
CIWEM has issued a policy position statement clarifying the responsibilities of water suppliers and property owners for water supply pipes. (More info
Researchers at Sheffield University have shown that four organisms isolated from tapwater, one of which was Methylobacterium
, were unable to form biofilms in isolation. When applied in co-culture with Methylobacterium
the other 3 formed biofilms within 72 hours. They suggest that “this bacterium is acting as a bridge, enabling other bacteria to attach to surfaces and produce a biofilm and it’s likely that it’s not the only one that plays this role”. They further speculate that “ it should be possible to control or even prevent the creation of biofilms in the water supply by targeting these particular bacteria, potentially reducing the need for high dosage chemical treatments”. They envisage being able to apply DNA testing to detect organisms capable of inducing biofilm formation. ( it is not clear how the authors think it would be possible to specifically remove or inactivate these organisms if detected MW)
Copper in drinking water linked with Alzheimer's disease.
American workers using a rabbit model have shown that trace amounts of copper in drinking water led to development of characteristic plaques in the brain accompanied by learning deficits.
) (Related reference
Hexavalent chromium standard – California
The California Department of Public Health is proposing a standard for hexavalent chromium which is 500 times more stringent than the safe level identified by the State's EPA. The proposed standard of 10 ppb is 10 times lower than the EPA standard for total chromium and if adopted could carry a high cost burden.
Magnetic ion-exchange for control of DBPs
An American company has taken forward the Sirofloc process by coating magnetic particles with ion-exchange resin to enable removal of organic precursors and colour from source water. It is also being developed for removal of phosphorus from wastewater. While FWR does not endorse commercial products this is an interesting development. (Manufacturer's Video
Water efficiency and charging policy
CIWEM has issued a policy statement proposing that to combat wastefulness and increase efficiency, basic water usage should be charged at low cost with an escalating tariff. (Press Release
Mycobacteria and biofilms.
A recent paper in the Journal of Applied Microbiology describes research to measure adherence and biofilm formation by cells of Mycobacterium avium
, Mycobacterium intracellulare
and Mycobacterium abscessus
on common household plumbing materials namely stainless steel, glass, zinc-galvanized steel, copper and polyvinyl chloride (PVC). Mycobacterium avium
, Myco. intracellulare
and Myco. abscessus
readily adhered and formed biofilms on all types of plumbing materials. Factors influencing adherence and biofilm formation were species, plumbing material and prior growth. (Abstract
Chloramination – a kinetic modelling approach.
A recent Australian paper notes that formation of chloramines and maintenance of a suitable disinfection environment requires careful control of several operational parameters at the plant and at different locations along the distribution system. A mathematical model to simulate different disinfection conditions, based on chemical equilibrium and kinetic calculations, both at the point of chemical dosing and downstream in the distribution system, was developed. Common operational parameters for chloraminated systems, such as initial chemical dosages and the chlorine to ammonia ratio, were assessed. In addition, simulations of some selected operational strategies, such as breakpoint chlorination and dosing control strategies (feed-back and feed-forward) at a re-dosing station, were conducted and assessed. This modelling approach can be used as a decision support tool for water treatment operators to manage and maintain disinfection. (Abstract
Water Safety Plans – distance learning course
The University of North Carolina, in collaboration with IWA and Surrey University, is launching in August a 10 week distance learning course on Water Safety Plans will. The course will be run on a recurring basis when demand requires.
Water usage in the home
The Energy Saving Trust has published a detailed and thought-provoking report on the use of water in the home based on over 100,000 submissions on line from consumers using the Trust's Water Energy Calculator. The report shows that metered households only used 3% less water than unmetered ones although the data is likely to be skewed by virtue of the contributors being interested enough in water usage to use the Calculator and submit data on-line.
Over ⅔ of water is used in showers, baths, lavatories and bathroom sinks with the average shower taking 7 ½ minutes. If every household took 1 minute less in the shower this would save £215 million each year in energy. It estimates that overfilling kettles costs around £68 million a year in energy.
Water saving campaigns may have adverse consequences
A recent Swiss-US study of a short-term water saving campaign found that, although the programme successfully reduced water use, there was also an overall increase in electricity consumption by participants. The group that received feedback and tips reduced water consumption, on average, by 6% or 15 litres per person per day, compared to the group who had received no feedback. However, in the same water-saving group, electricity consumption increased by 5.6%. This resulted in additional electricity use of 0.89 kWh per person per day. (Report
) ( The study was limited and not robust enough to yield definite conclusions
World water risk areas
A number of global maps are available on-line showing the extent of water risk including resource availability, risk of flooding, and seasonal variability. (Maps
Leakage reduction research
American Water is a partner to a USD 1.8 million, 2-year award from the Israel-US Binational Industrial Research and Development (BIRD) Foundation along with Stream Control Ltd for the development of an advanced pressured management system. This research project demonstrates the feasibility of installing modifications on existing pressure system controls that could reduce pressure in a system in response to reduced customer demand. International efforts to reduce leakage have confirmed that reducing excessive pressure not only reduces the volume of leaks through pipes but reduces the frequency of pipe failures. The expected outcome of the project will enable average reduction of water leakage significantly.
Virus concentration from water samples
The paper described earlier on this website is now published in the Journal of Applied Microbiology. It looked at the current state of the science of methods for the concentration of viruses from water. Several technologies were reviewed, and associated data were included in a meta-analysis which showed that electronegative filters, electropositive filters and ultrafilters are comparable in performance and that significant differences in recovery are due to virus type rather than filter type, water matrix or sample volume. This information is useful, as it will help to determine which method(s) should be used, particularly if there is a specific viral type being targeted for a particular study. In addition, it will be helpful when sampling different environmental water matrices and/or when budget allowance must be taken into consideration. Taken together, this will be useful in performing viral occurrence studies, which ultimately can help ensure safer water for both humans and the environment. (Paper
Legionella in Water Systems Code of Practice
The HSE is inviting comments by 23 August 2013 on a proposed revised Code of Practice on the Control of Legionella bacteria in water systems (consultation document
). The proposed revision does not radicaly change the advice in the current COP.
Risk map shows European ‘hot spots’ for pharmaceuticals in the environment
A paper has been published describing a newly developed tool which highlights ‘hot spots’ of pharmaceutical pollution in Europe, where human health and aquatic environments could potentially be affected. The tool provides for the location-specific prioritization of human pharmaceutical emissions in Europe, based on risk quotients for the aquatic environment and human health. Its application is illustrated for a set of 11 human antibiotics and 7 antineoplastics. Risk quotients for the aquatic environment were highest for levofloxacin, doxycycline and ciprofloxacin, located in Northern Italy (Milan region; particularly levofloxacin) and other densely populated areas in Europe (e.g. London, Krakow and the Ruhr area).The results suggest that the substances and locations posing the greatest risk are not the same for the aquatic environment as for human health. This is the first tool that can be applied to prioritise pharmaceuticals, locations and exposure groups to identify hot spots for monitoring, and substances for which additional data should be gathered (Summary
) A limited comparison with measured concentrations in surface water showed that predicted and measured concentrations are approximately within one order of magnitude.(abstract
Arsenic removal from groundwater
Within developing countries, groundwater provides an alternative drinking source to polluted surface water. However, the presence of arsenic in some groundwater sources has resulted in chronic worldwide poisoning. The aim of this review was to determine the effectiveness of field-based technologies for the removal of arsenic from groundwater in developing countries. (Paper
Development of a Bench-Scale Test to Predict the Formation of Nitrosamines
Results of a US Water Research Foundation funded development of a bench scale test to predict the formation of nitrosamines have been published. Although full-scale conditions cannot be exactly replicated in bench-scale tests, the tests shows that this can be a predictive tool.(More info
Alternative and Innovative Methods for Source Water Management of Algae and Cyanobacteria
The US Water Research Foundation has published the conclusions of a study of methods for managing algae and Cyanobacteria in Drinking Water sources. (Summary report
Hexavalent Chromium Occurence, Treatment and Costs
The US Water Research Foundation has published an up-date on progress with development of its Research Roadmap on Hexavalent Chromium in Drinking Water. (Details
UV disinfection knowledge base
The US Water Research Foundation has published a Knowledge Base book which identifies numerous statistics, conclusions, and recommendations for utilities with UV and considering or planning to implement UV disinfection. It is available as a hardback book with a CD-ROM of the database included, and as a PDF download on the Foundation Website. (More info
Reed bed treatment of waterworks sludge
Essex and Suffolk Water has officially opened the world's first site for the treatment of waterworks sludge using red beds. The 4.2 hectare site receives algae and silt sludge removed from Hanningfield Reservoir raw water and after passing through the reed beds the clarified water is returned to the reservoir. The site replaces a conventional sludge lagoon which has reached the end of its life. (More details
WHO Water Quality and Health Strategy
WHO has finalized an integrated strategy to guide WHO’s work on water quality and health, developed in response to the World Health Assembly Resolution 64.24. The strategy covers three separate areas of work: drinking-water quality, safe use of wastewater and safe management of recreational waters. (Document
Implications of Microbial Colonisation of Water within Buildings
UKWIR has published the above report (13/DW/02/67) which aims to provide water companies with an informed assessment of the current knowledge and understanding of the origin and behaviour of the organisms of potential health significance in plumbing systems. The review considers each organism separately and examines their ability to become established in plumbing systems, and suitable control measures. The risks presented by microbial colonisation of water systems in buildings predominantly concern Legionella
, although a range of other organisms have also been implicated recently including Pseudomonas aeruginosa
. These organisms are generally regarded as opportunistic pathogens, and have the shared ability to colonise plumbing systems. The study recognised that the water safety plan provides an ideal platform for managing the quality of water in buildings, and that all stakeholders have an important role in supporting their development. (Purchase report
Transporting large volumes of water around the Mediteranean
In order to transport large quantities of fresh water from ‘water-rich’ to ‘water-poor’ areas the EU-funded Refresh project has developed and successfully tested a flexible and cost-effective system to transport fresh water by sea using flexible plastic containers – water-bags – towed by a tugboat. The Refresh water-bag is a composite of modules which can combine to form a 20m-long, 4m-wide container capable of carrying 200 tonnes of fresh water.
Competitive water market saves millions in Scotland
Businesses in Scotland are spending £65 million less on water than they were five years ago, according to Business Stream, Scotland’s largest provider of non-domestic water and waste water services – and England is poised to follow suit with market deregulation expected there within a few years.
April 2013 marks the fifth anniversary of Scotland becoming the world’s first competitive non-domestic water market, which has achieved:
- More than £35 million in customers’ water consumption savings;
- More than 28,000 tonnes of carbon savings, the equivalent of taking 7,982 cars off the road.
- A reduction in water consumption of 16 billion litres, which equates to more than 59 million standard-sized baths.
- More than £30 million of discounts provided to customers.
- An increase in customer satisfaction by 26 per cent.
Chlorinous odours in drinking water
Australian workers report development of a new system for classifying water types according to the causes of chlorinous odours.Although causative compounds of the chlorinous off-flavours were not determined, bromine was proposed to play an important role in distribution systems where source waters have high concentrations of bromide that may not be removed by the available treatment processes. Management strategies for improvements in aesthetic water quality for each water type are proposed. (Abstract
Extreme water-related weather events and waterborne disease
A systematic review of reported waterborne outbreaks following such events explored their distribution between the different types of extreme water-related weather events. 322 waterborne outbreaks were analysed of which 53.7% were the result of contamination of the drinking-water supply. (Paper
The predictive value of total coliforms in drinking water
Total coliform and Escherichia coli
results from small drinking water systems tested over a 3-year period in British Columbia were analyzed using life table analysis. Small drinking water systems that have a non-E. coli
total coliform positive result have a slightly higher probability that a subsequent sample will contain E. coli
compared to small drinking water systems with no prior total coliforms detected in the distribution system (relative risk = 2.04) This is of minor practical significance due in part to the low rate of E. coli
-positive drinking water samples, reflected in the low absolute risk increase at 1 month after a non-E. coli
total coliform test (1.6%). (Abstract
Arsenic Contamination in the World
IWA has published an International Sourcebook which provides a global compendium of cited arsenic occurrences in the world as they affect public health. 82 countries have arsenic contaminateed drinking water supplies.The author has also written a comprehensive review article available to IWA members in the April 2013 edition of Water21 (details
Nitrosamines in N American drinking water
WRF has awarded a research grant to American Water to determine the occurrence of nitrosamines in American drinking water systems
The project will examine drinking water plants in the U.S. States and Canada to clarify the impact of various conventional and advanced treatment processes in minimizing the formation of nitrosamines.
Drinking Water Quality in Member States
The EC has published a synthesis report on the quality of drinking water supplies in the European Union for 2005-7. This is the 5th report in a series since 1993 and includes, as a minimum, all individual supplies of water exceeding 1000 m3
/day as an average or serving more than 5000 persons and covers three calendar years. The report says that compliance with the requirements of the Directive concerning information and reporting shows some significant disparities between member states and acknowledges that the data is incomplete. It says that,incomparability is due to amongst others various levels of compliance with the monitoring and reporting requirements, the lack of harmonized sampling and monitoring methods and the fact that not all Member States sample at the legal points of compliance. It comments that for the UK there was a sharp increase in non-compliant WSZs (Water Supply Zones) for the Coliform bacteria parameter from 5 WSZs in 2002-2004 to 117-144 WSZs in the 2005-2007 period. There was also an increase in the number of WSZs with non-compliance for iron, manganese and nitrite.
(2005-7 synthesis report
Control of Ps. aeruginosa in water systems
The Department of Health for England has published new consolidated guidance for healthcare providers, particularly in augmented care facilities, on the control of potential Pseudomonas aeruginosa
infection associated with taps, and water systems in general (guidance document
). This replaces earlier guidance issued in February 2012 (initial guidance
). Parts of this document apply to any water systems in buildings not just hospitals.
Doing away with bacteria in water systems using copper and silver
An EC funded project (SILCO) has demonstrated that harmful bacteria can be removed from water sources through the addition of copper and silver ions. The project has developed an innovative monitoring device that senses the elimination process of complex bacterial communities known as biofilm and unsafe bacteria from drinking water systems. The prototype successfully killed legionella bacteria at a natural source spa in Slovakia, helping to alleviate public health concerns associated with the potential contamination of water sources. (Summary
Electricity from water mains
Scottish Water has installed a turbine in a large water main near Falkirk. The turbine captures the energy which would otherwise be dissipated by a pressure-reducing valve, The first turbine of its kind in the UK, it is capable of generating enough green energy to power up to 150 homes. (Press release
New Research projects on VOCs in drinking water to be funded by US Water Research Foundation
WRF, in conjunction with USEPA, is inviting proposals for 3 Research projects on Treatment and Removal of VOCs (Volatile Organic Compounds). The projects are;
- Removal of Volatile Organic Contaminants (VOC) from Drinking Water via Low-Profile Aeration Technologies;
- GAC- Rapid Small Scale Column Test (RSSCT) at Low Concentrations of VOCs; and
- Reducing Volatile Disinfection Byproducts in Treated Drinking Water Using Aeration Technologies.
Fluoridation of drinking water benefits adults
The results of a study published online in the Journal of Dental Research, show that adults who spent more than 75 percent of their lifetime living in fluoridated communities had significantly less tooth decay (up to 30 percent less) when compared to adults who had lived less that 25 percent of their lifetime in such communities. (more
). The report concludes that fluoridated drinking water prevents tooth decay for all adults regardless of age, and whether or not they consumed fluoridated water during childhood.
World's largest desalination plant planned
Plans are in hand to build the world's largest desalination plants with an output of 600,000 m3
/d in Saudi Arabia.(Details)
Optimisation of Corrosion Control for Lead in Drinking Water Using Computational Modelling Techniques
This recent publication by IWA shows how compliance modelling has been used to very good effect in the optimisation of plumbosolvency control in the United Kingdom, particularly in the optimisation of orthophosphate dosing. Over 100 water supply systems have been modelled, involving 30% of the UK’s water companies. (Details
Effects of Temperature and pH on Reduction of Bacteria in a Point-of-Use Drinking Water Treatment Product for Emergency Relief
A paper about to appear in Applied and Environmental Microbiology reeports on The effects of temperature and pH on the water treatment performance of a point-of-use (POU) coagulant/disinfectant product.. Cold temperatures (∼5°C) reduced the bactericidal efficiency of the product with regard to Escherichia coli and total coliform log10 reductions. (Details
Cylindrospermopsin: occurrence, methods of detection and toxicology.
A review has been published
in the Journal of Applied Microbiology of current knowledge regarding this cyanobacterial toxin which is of growing interest. The only report described so far of human toxicity associated with CYN has been a hepatoenteritis incident in 1979, where 148 people were hospitalized from Palm Island off the coast of Australia.
Validating the cause of Coliform failures
A collaborative project between UKWIR and DWI on validating the cause of coliforms in drinking water in 2009 resulted in the production of guidance to water companies. It also recognised that there would be a benefit in the future to hold a workshop to provide an opportunity to review water company’s experiences with the guidance and for DWI to present their feedback on the situation. The workshop in March 2012 concluded that the introduction of the guidance has brought improvements in the success of investigations into the origin of coliform bacteria. The discussions and findings from the presentations and breakout sessions are being taken into consideration in the forthcoming UKWIR project “A forensic approach to understanding bacteriological infringements in the Water Network” (Summary report
Impact of language and cognition on compliance during a natural disaster
DWI contributed to a Kings College project analysing responses to consumer notices advising on precautions with water use from both the Mythe flooding incident and the Pitsford cryptosporidium event, ensuring that representative results of different event types were used to help highlight the factors behind non compliance.The research explored how and why professionals and the public differentially understand and communicate about risks and their prevention. The report provides advice to water companies on ways to improve communications with consumers in high impact events. (Full report
Health impacts from extreme events water shortages
Following a literature review and a workshop DWI, in conjunction with HPA, has published a report which concludes that there is little scientific evidence based information about the health impacts of water shortages during and after extreme events.
The report concluded that loss of water supply in conjunction with loss of power over time may create sanitation problems, so these events cannot be viewed only in terms of water quality. These impacts can be predicted in advance and planned for, in relation to alternate supply provision, advice to consumers and health surveillance.
Energy efficiency and carbon sensitive water management
A briefing report published by TRansitions to the Urban Water Services of Tomorrow (TRUST
), an integrated research project funded by the European Union, concludes that demand reduction,
through the reduction of waste and increasing water efficiency at the point of use offers savings of up to 10% by 2020 and at least 20% by 2050. Progressive improvements in the efficiency of conveyance and distribution should also be able to make a positive impact with improvements to motor and pumping efficiency within water treatment works reducing energy use by a further 10–45%. Other operational efficiency improvements have been
shown to reduce the total energy consumption by up to 40% in some cases. Replacement of Greenhouse gas-intensive treatment processes, such as GAC filtration, has also saved up to 40% of emissions. However, the savings potential for the water supply sector probably falls short of
the 80% emission reduction target for 2050.
The World Economic Forum has published Global Risks 2013 based on the views of 1000 experts. It covers five sectors -
- Societal, and
Water Supply is identified as the highest Societal risk and second overall. It is ranked 4th in "Likelihood" and 2nd in "Impact". For every risk that has been identified the publication illustrates how that risk has changed since 2011. Whilst "Water supply crises" has reduced fractionally since then, it is still the highest Societal risk by some clear margin. The only risk that is ranked higher is within the Economic sector - "Major systemic financial failure".
Pathogenic amoebae in household water systems
A recent paper describes 2 fatalities
in Louisiana from infections with Naegleria fowleri
associated with the use of unboiled tap water for sinus irrigation. In one case Naegleria
and other amoebae were isolated from an instantaneous water heater. There have been other reports of amoebic eye infections due to rinsing of contact lenses with tapwater. Although chloramination is effective against Naegleria
household systems can be colonised where water is warm.
Detection of enterovirus and norovirus in water
EPA method 1615 uses a combination of cultural and molecular methods for the detection of enteroviruses and norovirus. Unlike enteroviruses, norovirus cannot be cultured and the molecular method using a combination of reverse transcriptase and quantitative PCR has to be used. A study has been published which optimised the methods and determined recoverabilities (abstract
). While recoveries were variable but reasonable for enteroviruses, norovirus recovery was 30% in groundwater but much less in the other waters studied.
UKWIR 2014 programme published
UKWIR has published a list of 35 projects for 2013-14. These include projects on the pesticides standard, DBPs, lead pipe replacement and pathogens and viruses in source waters. (Full list...
Research considerations for more effective groundwater monitoring
A paper in the Journal of Water and Health (vol 10 part4) suggests that the value of monitoring for faecal contamination using indicator organisms rather than individual pathogens is questionable when used for drinking water. Most outbreaks in groundwater occur in systems that have not violated the US EPA's maximum contaminant limit (MCL) for total coliforms within 12 months before the outbreak. Additionally, environmentally stable viruses and parasites are often detected in drinking water samples with no detectable indicators. Recent detections of Escherichia coli
O157:H7 and Campylobacter jejuni
in groundwaters in the apparent absence of indicators also cast some doubt on the worth of indicators for faecal bacterial pathogens. Individual pathogen monitoring is now technically achievable but currently unreasonable due to the number of possible pathogens and the costs involved. Several alternatives to pathogen monitoring could significantly reduce the frequency at which pathogens occur in waters testing negative for indicators:
- increasing sample volumes for indicators,
- increasing monitoring frequency,
- using a suite of indicators,
- using a more conservative polymerase chain reaction (PCR) method,
- sampling when faecal contamination is most likely present or
- any combination of these options
Evaluating GAC filters
The US Water Research Foundation (previously AwwaRF) has published a report which aims to assist utilities in determining whether it is feasible to utilize existing GAC filter caps to (1) help meet DBP regulations through control of DBP precursors, (2) remove selected classes of trace organic contaminants, and (3) provide a barrier against deliberate contaminants. The project also helps utilities plan GAC replacement frequencies to optimize seasonal contaminant removal.
Desalination by forward osmosis.
Forward osmosis is being developed as a desalination technology which is claimed to require significantly less energy than reverse osmosis. Two plants are already operational in Oman and a framework agreement has been signed with on of China's largest water treatment companies. (more information
). For an explanation of the process see here.
A young Italian student has developed a simple solar furnace to transform salty seawater into drinking water. The device is similar to an inverted coffee percolator in which salt water is poured in a black vessel where it is heated and on evaporating it passes through a pipe to a lower bowl where it condenses. A total of 5 liters of drinking water each day can be collected through this system that costs just 50 dollars (39 euros) and is royalty free. (Details in French...
Sustainable Economic Levels of Leakage (SELL)
Ofwat has published a report on SELL which considers the level to which companies integrated the calculation of the SELL in to their wider water resources management plans during the last price review in 2009 ; the inclusion of social and environmental costs and benefits in the SELL and; where companies had included these, the report considered the appropriateness of the values used and recommends some improvements. It also includes a discussion on leakage management practices and techniques. This covers a wide spectrum of activities, such as the use of pressure management, and potential improvements companies could make. Ofwat will take the conclusions of this review into account when developing its approach to leakage regulation for the next price review and alongside the Environment Agency, expects companies to implement the recommendations, as far as possible, as part of the water resources plans they are currently drafting.
Nitrosamines in drinking water
DWI has published results
of further research on nitrosamines in water treatment coagulants and drinking water.
No concentrations of NDMA in final water exceeded the WHO guideline of 100ng/L, although some samples exceeded the tier 3 trigger level of 10 ng/L in the DWI guidance.
The principal source – or potential source - of nitrosamines (NDMA and NMOR) in drinking water appears to be contaminated ferric coagulants. It is suggested that manufacturers be required to analyse coagulants for nitrosamines and provide results to water companies to ensure that this contamination route is controlled. Should nitrosamines in drinking water continue to be a concern, removal by GAC adsorption may be particularly effective based on the results of laboratory tests with virgin GAC.
Sustainable Solutions: Raising the Water Mark
The Water for Life White Paper was published in December 2011, followed by the draft Water Bill in July 2012 which takes forward some of the concepts of the White paper. A number of stakeholders, including the Environment, Food and Rural Affairs Select Committee, have queried some of the plans and proposed timescales. Drawing together ten experts from across the water arena, this latest Westminster Sustainable Business Forum publication provides a platform for those involved to share their views and commentary on specific areas within the water sector. The collection of essays comprise a range of informed ideas about how to improve the water supply chain, expand debate beyond the scope of the draft Water Bill and create more sustainable policy within the water sector. Topics covered include sustainable abstraction, water efficiency, leakage, water metering, and the river catchment approach.
Westminster Sustainable Business Forum are a not-for-profit, cross-party environmental think tank.
Metaldehyde in drinking water
WaterUK has issued a briefing paper on the impact of agricultural use of metaldehyde slug pellets on drinking water. Current drinking water treatment methods designed to remove a range of pesticides are
not effective at reducing the levels of metaldehyde in water. There have been occasions when very low levels of metaldehyde have been detected in treated drinking water. These levels are extremely low – the highest being around 1µg/l and mostly much lower. However the levels are above the European and UK standards for pesticides in drinking water that is set at 0.1µg/l.The Health Protection Agency has confirmed that there is no risk to health from the
levels currently being detected in water supplies.The most sustainable solution is to control the pesticide at source to prevent metaldehyde getting into watercourses and rivers in the first instance. This is best achieved by changing the way metaldehyde is used in the catchment. (Briefing note...
Predicting THM formation
Using a combination of modeling and online water quality instrumentation, an empirical model has been developed to predict THM formation and embedded into a full-scale supervisory control and data acquisition (SCADA) system. Online water quality instrumentation provided input values to the THM model for total organic carbon (TOC), pH, and temperature. A hydraulic model was also embedded in SCADA, and provided residence time input values for the wholesale portion of the distribution system, which included large lateral pipelines, reservoirs, and pump forebays. Results from a 3-year evaluation showed that predicted THM concentrations were within 10 μg/L of the measured value 81% of the time. Real-time model predictions can provide an effective way to monitor the formation of THMs in a full-scale distribution system. (Abstract
A new generation of membrane filters are being developed which may lead to cheaper desalination. The membranes imitate to structure of a biological cell wall by forming a double layer of hydrophobic lipids with compounds known as aquaporins which transport water across the layers.or other inorganic materiaals which perform the same function. These membranes have not yet been commercialised but show considerable promise. (More details
Innovation needs of the water chain
Organisations including the Chartered Institution of Water and Environmental Management (CIWEM) and the UK Committee on Climate Change have come up with 10 recommendations they urge the Government to apply.
The report, entitled Sustainable Solutions: Raising the water mark, was compiled by the Westminster Sustainable Business Forum, a coalition of leading UK businesses, government agencies, parliamentarians and organisations working to promote effective sustainability policy in the UK. It lays out advice on a variety of water issues including the role of management incentives in guaranteeing water security and the removal of red tape around water metering roll-out.
The report, formally unveiled in Parliament on Monday November 12th, also calls for changes in the regulation and ownership of dirty water treatment, setting tougher leakage targets, and the removal of barriers to entry to the industry, especially for innovative SMEs.
Leakage from supply pipes
Fixing leaks in supply pipes could reduce leakage by 30%. In its new policy position statement ‘Water Supply Pipes’, the Chartered Institution of Water and Environmental Management (CIWEM), has called on water companies to adopt customer-owned water supply pipes. This would enable more scope for leakage reduction and lead pipe replacement.
Around 30% of leaked water is estimated to arise from customer-owned water supply pipes yet many customers are unaware of their responsibility to keep the supply pipe in good order and to fix leaks.
An initial cost benefit analysis conducted by UK Water Industry Research (UKWIR) on water company adoption of supply pipes, concluded that it would cost an additional £4 per property per year which would be offset by the fact that the property owner would no longer need to pay for any repairs, maintenance or insurance for their water supply pipe (estimated at around £35 per property per year).
The benefits of water company adoption include, allowing the economic level of leakage calculations to include supply pipe replacement as a demand-side intervention; the development of supply pipe serviceability criteria; improved opportunities for innovation and operational performance and improved customer relations in the longer term.
Growth and biocapacity in Arab countries
Measured by the increase in gross domestic product over the past 50 years, Arab countries did well, as average GDP per capita increased by about four-fold.
While this was reflected in a higher standard of living, it did not necessarily lead to a better quality of life, nor did it enhance the chances of sustainability. The same period witnessed a steady deterioration in the natural capital and environmental conditions, putting the region at the brink of ecosystems bankruptcy. (Report...
India's first water e-magazine
Free access to this interesting new magazine “Everything About Water” is available by e-mail
. A useful insight into water issues beyond Europe.
Impact of covered streams on water quality
New EPA research suggests that buried streams may contribute to the degradation of water quality in the US. Consequently, scientists offer a simple solution: un-bury the streams.
Researchers have shown that streams open to daylight and air are up to 23 times more effective than buried streams at processing nitrogen. (More...
Arsenic and cancer risk
An EU study conducted in Hungary, Romania and Slovakia has concluded that long-term, low level exposure to arsenic in drinking water may increase a person’s risk of skin cancer. The study suggests that levels of inorganic arsenic previously thought to be harmless may have a carcinogenic effect over a longer period of time. The study focussed on indivduals exposed to >40 micrograms/ litre over a lifetime. Although the EC Directive sets a limit of 10 micrograms/litre this may well be exceeded in some private supplies. Details...
WRc consult on National Innovation Accelerator for Water
The Water Research Centre (WRc) has proposed an easier entry process into the water sector for innovative technologies and solutions. The proposal is in response to existing testing and demonstration facilities that are dispersed across a small number of sites, which are often under-utilised as they tend to be regional rather than national.
According to the WRc independent co-ordination of these facilities, under proper governance, would provide a national capability for testing and demonstrating innovative solutions. The use of these facilities under agreed and well defined operational conditions with unambiguous, evidence based and transparent reporting would accelerate adoption and incentivise the supply chain to invest in more innovation for the water sector.
Preventing interruptions to water supplies
UKWIR has published a report evaluating the various under-pressure techniques for work on water mains with a decision support tool to assist in assessing the relative cost-effectiveness of under-pressure techniques versus conventional methods. Summary
Children at risk from rural private supplies
Researchers at the University of East Anglia have shown that children under 10 are at significantly increased risk of infectious intestinal disease when dependent on private drinking wter supplies. Older children and adults show no increased risk.
Survival and persistence of nonspore-forming biothreat agents in water
Six potential biothreat agents were tested for the ability to survive or remain viable in unchlorinated drinking water at 5, 8 and 25°C. All remained metabolically active for 30 days although not necessarily culturable. Francisella tularensis
was culturable for at least 21 days at 8°C abstract
Bacteria in distribution
University of Michigan workers have shown that the bacterial flora in a distribution system was largely influenced by the stable bacterial community of the dual-media rapid sand filters despite chloramination of the finished water and backwashing of the filters with chloraminated backwash water.. They suggest that the bacterial community in a distribution system could be controlled by manipulation of the filter bacterial community. Abstract
Skin irritation and tap water.
WRc has published has published results of a literature survey commissioned by DWI on Skin Irritation and Tap Water Quality (report
) There have been unsubstantiated reports in the literature and frequent claims from consumers that skin problems have been caused by tap water. The Report concludes that there is insufficient evidence to reach any conclusion about any association between skin irritation and tap water,. It outlines a number of variables to be considered in any future studies, which it considers are much needed.
Mains lining materials
DWI and WRF jointly commissioned a review of the impacts of mains lining materials on water quality (abstract
) The report compiles and synthesizes information on water quality impacts caused by different lining materials. It reports tests on lining materials used in distribution systems that may release compounds with potential health effects into drinking water and also studies the effect of distribution system conditions on the leaching potential of lining materials. There were no issues identified in this study that might invalidate current UK guidance and codes of practice on lining technique and methodology.
Nanoparticles and drinking water
There is increasing concern over the health effects of engineered nanoparticles (ENPs). DWI has publiished a report which explores the potential for ENPs to contaminate drinking water supplies and to establish the significance of the drinking water exposure route
compared to other routes of exposure. It did not imply or consider health risks from the presence of ENPs
. A range of metal, metal oxide and organic-based ENPs were identified that have the potential to contaminate drinking waters. Worst case predicted concentrations in drinking waters were in the low to sub- µg/l range and more realistic estimates were tens of ng/l or less. For the majority of product types, human exposure via drinking water is predicted to be less important than exposure via other routes. The exceptions were some clothing materials, paints and coatings and cleaning products.
Particles contained in these products include Ag, Al, TiO2
and carbon-based materials. Although predicted concentrations of these materials in UK drinking water are low, any future work on risks of ENPs to drinking waters should probably focus on these materials and the development of the UK market for products containing these materials. It is clear from this study that there are significant gaps in our current knowledge regarding the use, environmental fate and exposure of ENPs in the UK environment, and recommendations for future studies are made in the report. It should also be noted that this is a product by product analysis and does not reflect human exposureat an individual level. ( summary report
Veterinary medicines in drinking water
DWI has published results of a desk study of current knowledge on veterinary medicines in drinking water and estimation of potential levels (full report
). Aftera review of published literature on the fate and occurrence of veterinary medicines in the environment and assessment of use in England and Wales, modelling identifed those substances of potential significance. Using very conservative assumptions four substances were identified that in groundwater could potentially exceed the Acceptable Daily Intake and therefore warrant further study. Although a risk from these substances cannot be ruled out, the modelling process adopted very conservative assumptions and where data were not availble, conservative defaults were used.
Alternatives to phosphate for plumbosolvency control
UKWIR in collaboration with DWI has produced a report which includes a software tool to allow water companies to identify the overall net position of the costs and benefits associated with a selected course of action relating to plumbosolvency control over an investment planning timescale. The tool also provides information on costs and benefits relating to different aspects of plumbosolvency control, both in terms of an overall summary for the region to which the model relates, but also at smaller spatial scales such as by water supply zone (WSZ), by the area served by a particular dosing point and by wastewater treatment works (WwTW).
Liquid-infused structured surfaces with exceptional anti-biofouling performance
Workers at Harvard University have developed a procedure for immobilising a film of fluorinated hydrocarbon on surfaces which prevents adherence and build-up of biofilms on surfaces. They claim that the SLIPS (Slippery Liquid-Infused Porous Surfaces)-based antibiofilm surfaces are stable in submerged, extreme pH, salinity, and UV environments and are low-cost, passive, simple to manufacture, and can be formed on arbitrary surfaces. They anticipate that their findings will enable a broad range of antibiofilm solutions in the clinical, industrial, and consumer spaces. (Unlikely to be of application in water mains in the forseeable future but an interesting idea Mike Waite
Mycobacterium avium complex – the role of potable water in disease transmission
This paper reviews current literature and case studies regarding the wide spectrum of disease caused by MAC and the role of potable water in disease transmission. Potable water was recognized as a putative pathway for MAC infection. Contaminated potable water sources associated with human infection included warm water distribution systems, showers, faucets, household drinking water, swimming pools and hot tub spas. MAC can maintain long-term contamination of potable water sources through its high resistance to disinfectants, association with biofilms and intracellular parasitism of free-living protozoa. Further research is required to investigate the efficiency of water treatment processes against MAC and into construction and maintenance of warm water distribution systems and the role they play in MAC proliferation.(full text
Blueprint to safeguard water resources – European Parliament
Access to water should be a fundamental and universal right, according to a non-binding resolution ( words or deeds? MW) voted by the European Parliament on Tuesday. Clearer water pricing schemes, better wastewater management, blue flags for rivers and attaching water-saving conditions to farming and energy subsidies are among the suggestions tabled by MEPs.
Water "is a shared resource of humankind and a public good. Access to water should constitute a fundamental and universal right", says the resolution, drafted by Richard Seeber (EPP, AT) and approved by a show of hands.
Reducing water consumption should therefore be a priority, MEPs say. They insist on the need for an audit of the state of Europe's water network, "given the possibility that as much as 70% (!!) of the water supplied to European cities is lost as a result of leaks in the water system", and stress the need "to encourage infrastructure investments". They also recall that about 20% of water in the EU is lost due to inefficiency. Details....
Better implementation of European water legislation needed
The European Parliament on July 3rd adopted a report which calls for better implementation of the current water legislation and identification of new challenges and gaps in order to achieve long-term sustainability of water resources.
The main objective of report is to ensure access to good quality water in sufficient quantity for all European citizens. The key points of the report include:
- more efficient and sustainable management of water resources and ecosystems (on river basins across the borders),
- expanding the scope of water protection to all waters,
- achieving environmental and consumer conditions for all waters implementing by new EU legislation,
- mechanism for controlling of pollution at water sources (emission limit values, "polluter pays" principle),
- streamlining of consumption measurement systems (inefficient use of water resource, leaks in the distribution),
- promoting wastewater policy (recycling facilities and developing financing strategies for wastewater infrastructure),
- evaluating the sustainability of new renewable energy sources,
- streamlining and simplifying new legislation
Notes: The European Commission will publish in November this year a "Blueprint to safeguard Europe“s water resources as the EU policy response to current and future water challenges and ways to improve EU“s water resources efficiency.
Draft Water Bill published for pre-legislative scrutiny 10 July 2012
The draft Bill includes measures to strengthen the water sector’s ability to respond to the challenges of a growing population and less certain water supplies, and improve the deal it offers to its customers by offering more choice, and driving efficiency and innovation.
At the heart of the Water Bill are measures to give businesses and other non-household customers in England more choice by enabling them to switch their water and sewerage suppliers and to remove some of the existing regulatory requirements that act as a barrier to entrants wishing to enter the market.
A combination of greater pressure on suppliers from customers entitled to switch and new players will create a more vibrant and competitive market, bring new ways of working to the water sector, improve customer service and help keep the cost of bills down.
Comments can be given to defra
Water Consumption Labelling Scheme for taps etc
The European Association for the Taps and Valves Industry has adopted a labelling scheme to help improve the water consumption and performance of taps, valves and shower heads. Brochure..
Reducing costs of desalination
Singapore is trialling new technologies to reduce the cost and energy demands of desalination. It is hoping that the current 3.5kWh (kilowatt-hour) of energy needed to produce a cubic meter of water will be reduced to less than 1.5kWh using the latest technologies.
One technology being trialled is Siemens' electrochemical desalination, which instead of pumping seawater through membranes to remove salt, uses an electric field. Using lower pressures than traditional reverse osmosis desalination, the trial unit is already treating 50 m3 per day reportedly using half the usual amount of energy.
There are plans to use biomimetic membranes, also known as biomimicry.which are inspired by how pores in the human body and even plants filter out contaminants and transport water. The idea is that the replicated membrane rejects specific, targeted salts and transports water at lower pressures.
It is believed that with further research breakthroughs in this area, desalination energy consumption could be reduced down to 0.8 kWh/m3. That is a huge leap from current energy requirements yet the industry is clearly cautious over the time required to fully commercialise research. More details...
Water Safety Plans and small community supplies
WHO has published on 1 July 2012 “ Step-by-step Risk Management Guidance for Drinking-water Supplies in Small Communities”.The Manual provides guidance on how to apply effective and achievable management actions in order to improve the safety and quality of supplied water. It outlines how to develop and implement Water Safety Plans by 6 achievable tasks. Relevant to all community-managed systems, it is applicable to piped schemes, point sources such as hand pumps, protected springs or household rainwater harvesting systems and other sources. The guidance provided is valid for both new and existing schemes.. This manual complements and is in-line with the WHO/IWA WSP manual targeted at larger, piped systems (2009
Pharmaceuticals in Drinking-water
Trace concentrations of pharmaceuticals reported in drinking-water have raised concerns over the potential health risks they may pose. This WHO technical report takes into consideration the available scientific evidence to support the management of such concerns. It emphasizes the need to consider this emerging issue in the overall context of drinking-water safety management, which includes microbial and other chemical risks. The report concludes that exposure to very low levels of pharmaceuticals in drinking-water is unlikely to result in appreciable risks to human health, rendering corrective measures unnecessary. Download the final version of this document
Desalination in Israel
The Israeli Water and Energy Minister has announced that “by the end of the decade, desalinated water will flow from the Western Mediterranean Sea to almost every house in Israel. "By the end of the decade the water we'll all drink will be desalinated
” Israel currently uses 1.2 billion m3 /year of potable water.
Groundwater and Endemic Disease
The outcomes of a large epidemiological study
investigating microbial disease risks from drinking untreated groundwater have recently been published. Viruses were detected in untreated groundwater from all systems and the addition of UV disinfection resulted in a large decline in virus levels immediately after the disinfection point The results indicate that untreated groundwater supplies meeting current US water quality standards can be a significant source of acute gastrointestinal illness (AGI)
in the communities they serve.
Endocrine disruptors and drinking water
DWI has published an assessment of published data
on the presence of potential endocrine disrupting chemicals in drinking water. After prioritisng the 325 candidate substances, substances were allocated a margin of safety (MOS) based on potential daily intake and tolerable daily intake or relevant available hazard data. The MOS was the tolerable daily intake divided by the potential intake by an infant ( the most sensitive group) This resulted in 35 substances being selected for further evaluation on the basis of possible concentrations ≥100ng/L occuring but 21 of these still had MOS; >100 and 8 of >10 and were not considered further. For 6 chemicals (p-benzylphenol, dibutylphthalate, 4-nitrophenol, digoxin, fluticasone and salbutamol), MOS were ≤10, and hence were considered to warrant a more detailed consideration to establish the likely ‘real world’ situation, as opposed to the estimates derived here from the use of highly conservative ‘worst case’ assumptions throughout the modelling process.
Water security projects funded
It is estimated that by 2050 the UK will have a shortage in water supply of up to 10,000 million litres a day. Innovative new technologies and services are needed if we are going to find a solution to this key issue. heTechnology Strategy Board has anounced that ten small to medium sized companies in the UK are set to deliver innovative feasibility projects designed to help businesses safeguard our future water supply, both in this country and abroad. Feasibility projects aim to enable businesses to develop their early stage ideas for innovative new technologies in the expectation that they may go on to be larger projects and give birth to the new markets of the future.
The total cost of the projects with business investment is just over £1 million with over £500,000 worth of funding from the Technology Strategy Board and up to a further £100,000 being put forward by the Natural Environment Research Council (NERC) and the Engineering and Physical Sciences Research Council (EPSRC). The Technology Strategy Board also announced £2.5 million of aligned funding for larger CR&D projects in February with results due to be announced in August. Both competitions have also been supported by the Department for Environment, Food and Rural Affairs (DEFRA) who have contributed £1 million. water security funding
Capture of water from power station emissions
The EU funded CapWa project is looking at capturing water from power plant stacks and filtering it through selective hollow fibre membranes to turn water consuming power plants into water producers. The project to develop suitable membranes is yielding promising results and if successful could make a contribution to the world-wide water shortage. water from air
Barriers to acceptance of reuse of recycled water
The Australian Water Recycling Centre of Excellence has awarded $3 million for a research project to investigate and address the barriers to public acceptance of reusing water for augmenting drinking water supplies.
The ultimate goal is to develop tools, methods and materials that water utilities, educators and regulators can use to provide consistent information across Australia, and to increase community understanding and build acceptance of water recycling and reuse as an option for an alternative water source. (This project may yield results relevant to the UK
AUSTRALIA ‘NEEDS NATIONAL GROUNDWATER STRATEGY’
A discussion paper from the National Centre for Groundwater Research and Training says that Australia will not have enough fresh water to meet the combined needs of a rapidly-growing population, expanding industries and conservation of native landscapes in the mid-21st century if it fails to articulate a national groundwater strategy for the future. Without a plan, major cities, industries such as mining, energy, agriculture and manufacturing and the preservation of the Australian landscape could all run into water scarcity problems within a decade or two.
Cloud computing aids leakage detection
An Israeli software company has developed a programme which takes existing data from the distribution network, including sparse and noisy data, analyzes it using algorithms and mathematical models and figures out the "normal behaviour of the network". It then looks for anomalies, including network flaws such as leaks, open valves and faulty equipment. Once an event is identified, hydraulic and mathematical processes are applied in order to establish the event's exact type, location, and magnitude. The utility can then be notified by multiple interfaces, including web, email, or SMS on mobile phones. TaKaDu
. The technology has already been used in Portugal and by Thames Water.
Effectiveness of water-efficient appliances
Rebates and exchange programmes for showerheads, toilets and washing machines can produce significant water savings, according to a US study
. The study observed a 6 to14% reduction in household water demand for the first two years after these efficiency programmes were introduced by a water authority in Florida. Savings continued but to a lesser degree in subsequent years.
Concern over UK's water security
The Institution of Civil Engineers has published its State of the Nation: Water report in which it warns that the urgency and severity of the UK's water issues are still not properly understood and that the recent droughts have been a "wake-up call".
rates the UK's current water security levels as 4 on a scale of 1-10, and in response ICE is now calling for the creation of a UK Water Security Taskforce to deliver an integrated roadmap to water security by spring 2014, based on strategic plans from all Governments.
Recycled water from ‘managed aquifer recharge’ safe for irrigation
The health risks to humans of using recycled water to irrigate crops needs to be carefully managed. New research
has demonstrated that ‘managed aquifer recharge’ can be just as effective as conventional water treatments in improving the quality of recycled water for use in irrigation.
Plastic pipes and leakage allegations
The British Plastics Federation’s plastic pipes group has criticised Ofwat
, the economic regulator for water and sewerage services in England and Wales, for what it calls ‘ill-advised and groundless’ comments made about leakage problems with high density polyethylene (HDPE) pipes.
Ofwat was quoted – the regulator says out of context – as saying HDPE pipes can begin to leak not long after they have been installed.
A BPF spokesman is quoted as saying: ‘It is well known that the water utilities companies operate variable jointing and installation standards and that this can compromise the performance of the system. A lack of training, correct tooling and supervision result in poor installation, which is susceptible to leakage.’
The gas industry uses the same HDPE pipes but does not have a comparable leakage problem, the BPF added.
Queen's Speech includes a Draft Water Bill
The draft Water Bill included in the Queen's Speech is expected to take forward the White Paper Water for Life
, issued in November 2011.
It is expected to increase scope for competition, making it easier for business users to change suppliers (while still not allowing domestic customers to change), and to facilitate trading of abstraction licences. In promoting water use efficiency it is not proposing to require universal metering. It is expected to strengthen the powers of Ofwat in line with increased competition proposals.
Water use and waste in the kitchen
In a limited study in 81 households in Germany, Italy, Sweden and the UK, workers showed that over 50% of water used in the kitchen was for dishwashing. Per capita use was significaantly higher in 1 or 2 person households. There were national differences in how much water was used for various purposes and the workers concluded that there are potential water savings
to be made in dishwashing practices.
Annual Water Company Performance Survey results published by British Water.
The survey ranks companies according to contractual approach, attitude, professional qualities, impact on supply chain, procurement, following policy, communication, partners/main contractors and AMP4/AMP5 transition and recession. Full results...
Random daytime sampling for lead
Random daytime (RDT) sampling for lead in drinking water has been used in the UK since 1989 for regulatory compliance assessment and since 2004 in the Netherlands. In 2008, RDT sampling was recommended to the European Commission as the method to be used throughout the European Union but there are concerns about the representativeness of this method, being of relevance to the protection of human health in water supply systems. This issue has been investigated using an established computational modelling system, from which it was concluded that: (i) RDT sampling as practised in the UK is adequately representative of the range of circumstances that occur; (ii) for houses with daytime residency, RDT sampling is not sensitive to the time period of sampling, unless it is constrained to only a few hours; (iii) for houses without daytime residency, RDT sampling of houses elsewhere with daytime residency is adequately representative, for the total periods of water use; (iv) for houses without daytime residency, random sampling just before or after ‘normal office hours’ will not be representative for checking zonal compliance; (v) it is important that seasonal variation is accommodated; and (vi) adequate reproducibility can be achieved if at least 100 samples are taken annually and if results are aggregated for several years.
Drinking Water in France
A recent French report
says that “ the quality of water delivered to each home is excellent because its microbiological conformity is 98% and its physico-chemical conformity is 97%”. 99.98% of samples from public supplies in England and Wales met the appropriate standards in 2010. It reports the average French household spends 1.25% of available income on water and sanitation , the distribution networks have leakage of 24% and the mains renewal rate is 0.61% p.a. Leakage in England and Wales is around 20% and mains renewal rate currently is approximately 0.6%.
Desalination in Australia
The Australian Water Minister when inspecting the construction of the second phase of the Southern Seawater Desalination Plant in Western Australia said that when the work is completed most of the population will be receiving about half of their drinking water supply from the Indian Ocean- independent of rainfall. More...
Amber light given to South Staffs takeover of Cambridge Water
A merger between Cambridge Water and South Staffs Water has been provisionally cleared by the Competition Commission.
An inquiry launched in January found the merger could result in a "small degradation" of service standards for Cambridge Water customers, and the loss of that company's "distinctive approach" as a benchmark. However, it said the merged company could be able to set higher standards than before in other areas and the overall impact would be small. CC deputy chairman Simon Polito said: "On balance, we do not believe the merger will significantly hinder Ofwat's task of assessing water companies' performance and setting price controls."
The commission is inviting views on its provisional findings and is due to reach a final decision by 20 June.
Reuse of municipal wastewater
The National Research Council of the National Academies in the U.S. has released a major report on water reuse. The report, entitled ‘ Water Reuse: Potential for Expanding the Nation’s Water Supply Through Reuse of Municipal Wastewater’ addresses possible applications of water reuse including drinking water, non-potable urban uses, irrigation, industrial process water, groundwater recharge and ecological enhancement
A useful precis of the report is available
Progress on Drinking-Water and Sanitation
The WHO/Unicef Joint Monitoring Programme set a Millennium Development Goal of halving by 2015, the proportion of people without sustainable access to safe drinking-water and basic sanitation. On 6 March 2012 the JMP published a joint report showing that in 2010 the world met the drinking water target. However, 11% of the world's population – 783 million people – remain without access to improved water sources. However progress toward the sanitation target is behind schedule. Both for water and sanitation, huge disparities remain between regions, between urban and rural areas and between rich and poor. The report can be downloaded from the JMP website.
Welsh Water/Dŵr Cymru to open new laboratories
Welsh Water is bringing water quality checks back in-house with new laboratories in Newport and north Wales. The utility, which previously contracted out the analysis of around 300,000 drinking water samples a year, is investing £8.6 million in the two facilities.
The Newport laboratory is due to be up and running at the end of 2012 and employ 40 people. A smaller laboratory of 10 staff, at Bretton in north Wales, has recently become operational.
Gold nanoparticles enable 5 minute test to identify bacteria
Researchers have developed a chromogenic test using gold nanoparticles which can identify Salmonella
in 5 minutes. They report that the technique can be applied to drinking water and has been used to identify E coli
. Published details
are limited as the method is to be patented.
Monitoring of biofouling on ultrafiltration hollow fiber membranes by rapid enzyme activity assays
by Norwegian workers concludes that esterase and peptidase enzyme activity could be used to predict the permeability decline and potentially be used for e.g. at-line monitoring of membrane biofouling.
Demonstrating the effectiveness of a Water Safety Plan
Many countries around the world are adopting the Water Safety Plan (WSP) concept, a proactive, risk-based model for ensuring consistent confidence in drinking water safety, accessibility and affordability. While it is widely accepted that the WSP concept is an appropriate tool for ensuring drinking-water supply efficiency, the process for gathering the required evidence to demonstrate this continues to be rather vague. The problem may lie fundamentally in the way WSPs are developed and implemented. A paper from New Zealand
discusses the need for establishing performance targets, identifying key performance indicators and monitoring these to build a body of evidence that would be instrumental in demonstrating whether WSPs are effective or not.
Bristol Water announces proposed new reservoir site
Bristol Water has chosen a site near its existing Cheddar Reservoir for a proposed new reservoir although full consultation is to take place before any planning application is made. Ofwat agreed that the Company could prepare a detailed design and planning application in the period 2010-2015 and construction could not begin until at least 2016.
Smart meters help tackle leakage.
Yorkshire Water is using wireless datalogging automatic meter readers
to significantly reduce the time and cost taken to find and fix leaks in the network.
The meter readers along with ‘bolt-on' in-line flow meters, enabled Yorkshire Water to split 250 of its existing District Metered Areas (DMAs) in half for more efficient water management without the need for constructing any new, expensive metered bypasses. The initial phase includes 350 installations, with more planned to follow as the project rolls out across the network. In a series of blind pilot trials conducted last year to compare the before and after effects of the project, results indicated an average saving per leakof roughly 60 hours of detection time and over £1500, even without factoring in the initial saving of £5000+ per sub-metering point created.
Lead and copper don’t mix
Research published in the Proceedings of the 2011 Water Quality Technology Conference
confirms that joining old lead pipes with new copper lines using brass fittings spurs galvanic corrosion that can dramatically increase the amount of lead released into drinking water supplies and last for a long time. This phenomenon has long been recognised.
The study suggests that safety-minded, lead-pipe-removal programs at water utilities across the country actually may be increasing the risk of lead exposure for water customers.
UKWIR release Managing Leakage 2011
October saw the release of Managing Leakage 2011, [10/WM/08/42 Managing Leakage 2011 (1 84057 563 8)] a comprehensive update of the groundbreaking Managing Leakage series of reports issued by the water industry in 1994. The original publication became the manual of best practice in the UK and internationally and was instrumental in helping water companies to reduce their leakage. Managing Leakage 2011, has drawn on results from UKWIR's leakage programme which began in 1994 and comprises some thirty projects.. The release comes in the form of a short printed summary
accompanied by a CD holding the text of seven individual reports. The CD is fully linked to help guide users interested in a particular leakage issue, through the reports with the ability to check all the referenced documents.
Ultrasonic cleaning technology
A team of scientists from the University of Southampton have been awarded the Royal Society Brian Mercer Award for Innovation 2011 for their development of a revolutionary ultrasonic attachment for taps
which generates both bubbles and ultrasound and massively enhances the ability of water to clean.
The device works with cold water, minimal additives and consumes as much electrical power as a light bulb. Licenses have already been sold to a number of industries to look at cleaning in food preparation, hospitals, manufacturing and the home. The new technology consumes less water and power than the established competitor technologies. ( Potential for biofilm removal? Mike Waite
Ofwat unveils new price limits consultation
On November 23 2011 Ofwat published a consultation document
on how it intends to set limits on the prices water and sewerage companies can charge customers in the future.
Spatial variation of waterborne Escherichia coli – implications for routine water quality monitoring
Work carried out in North Wales
has shown that the side of the river that routine water monitoring samples are taken from can make a significant difference to the classification of microbial water quality. This has important implications for sampling strategies and the use of microbial source tracking (MST) techniques.
Caffeine as an indicator of human contamination of surface waters
is commonly used to evaluate the levels of faecal pollution of surface water but non-human sources can contribute significantly to the levels that are observed
The presence of caffeine is a sure indicator of human sewage contamination, as agriculture and industry do not tend to release caffeine into the environment.
A Canadian study
looking at storm water discharges has determined that there is a strong correlation between the levels of caffeine in water and the level of bacteria, and that caffeine levels can be used as an indicator of pollution due to sewerage systems.
Scottish Water extends network using gas mains
Scottish Water has utilised an abandoned gas mains as a 'sleeve' for a new water mains extension and the work, which is almost complete, has been successful on all counts
. It has not only increased supply, it has improved efficiency by reducing leakage, it has saved money, disruption and is a more environmentally sound alternative to traditional installation methods.
Lower threshold for switching water supplier.
More businesses across England will be able to choose their water supplier in search of a better deal under changes to be introduced shortly by the Environment Minister, Richard Benyon. Currently only businesses who use more than fifty megalitres of water a year can switch from their existing water supplier to a new one.
Government proposals to slash this threshold to just five megalitres of water will substantially increase those able to switch supply, from just 2,200 to 26,000 businesses. The change, which is subject to Parliamentary approval, is an amendment to the Water Industry Act 1991. It is hoped the change will be enacted by the end of the year.
Water filtration for excavations
A new system to ensure wastewater from maintenance excavation is as clean as possible before being discharged has been introduced by Electricity distributor UK Power Networks.
The system, introduced on September 9, comprises a filter bag fitted to the end of pump hoses to collect sediment and up to 2.5l of oil from water removed from excavations. Once attached, the bag is simply placed on the grass verge or roadway so the filtered water can flow out the bottom of the bag and soak or drain away. The high-visibility bags can be reused several times, says the company, as an indicator strip along the side shows if it is still viable. And the waste collected can be disposed of in general waste containers, providing it is not heavily contaminated.
Adverse effects of disinfection by-products
University of Illinois scientists report
the first identification of a cellular mechanism linked to the toxicity of mono-haloacetic acids, which occur as DBPs. This study, published in Environmental Science & Technology
, suggests a possible connection to adverse health effects, including neurological diseases such as Alzheimer's.
OFWAT summary of Water Company performance 2010-29011
Ofwat has published its summary of performance of Water Companies in England and Wales for 2010-2011
. Main conclusions are that:
- Complaints have fallen by 20 percent in the last two years, and overall customer satisfaction with the way companies deal with contacts and concerns is high.
- Drinking water quality remains up there with the best in Europe.
- The number of incidents of properties suffering internal sewer flooding was lower than any of the previous four years.
- All companies are making sure they have appropriate water supplies to meet their customers' needs.
There are still some areas of concern. For example:
- six companies failed their leakage targets
- seven companies need to do more to maintain their underground infrastructure to a satisfactory standard
- there was a high number of supply interruptions to customers.
Ofwat launches regulatory compliance consultation
Ofwat has published a consultation document
, outlining proposed changes in the way it approaches regulatory compliance, shifting responsibility and accountability towards water and sewerage companies (WaSCs). Under the proposed changes water and sewerage companies will be responsible for implementing their own systems and processes.
Effect of intermittent addition of polyelectrolyte on filtered water quality.
Results of experiments carried out in Turkey on the effects of intermittent polyelectrolyte addition on the quality of effluent water and on the development of filter headloss have been published
. Anionic and cationic polyelectrolytes were applied to two similarly constructed pilot sand filters. Intermittent addition of polyelectrolyte produced better effluent quality and reduced the polyelectrolyte consumption by half with much less headloss.
Managnese in drinking water and IQ
A Canadian study
has assessed the relationship between exposure to manganese from drinking water and IQ in school-age children living in communities relying on groundwater. The study showed that lower IQ was significantly associated with higher estimated manganese intake from water consumption but not from food. As manganese occurs commonly in drinking water and the effects seen in this study were at low Mn levels in drinking water, the authors propose that the guidelines for safe manganese in water should be revisited, although the current WHO Guidelines for |Drinking Water Quality consider Manganese to be of no health concern.
Rabbits as a source of cryptosporidium
was first identified as a human pathogen during a waterborne outbreak in Northamptonshire in 2008, and its epidemiology has now been described for sporadic cases in the United Kingdom
. C. cuniculus
from rabbits currently makes up a minor fraction of human cases of illness, In total, 37 (1.2%) of 3,030 infections were caused by C.cuniculus
: 23 in 2007 and 14 in 2008. It has the potential to cause waterborne outbreaks given the right circumstances. C. cuniculus
oocysts would have been detected by currently used techniques, but probably misclassified as C. hominis
. The potential for rabbits to contribute to water contamination must therefore be considered in water quality management strategies.
Is 100% compliance with Drinking Water Quality Standards achievable?
UKWIR has published a report
which questions whether it is possible to achieve 100% compliance with drinking water quality standards, or justifiable to seek to do so. The costs and environmental impact of seeking fractional and incremental improvements may be disproportionate to the benefits, which may have limited health benefits if any.
Norovirus survival in groundwater
American workers have shown
that Norwalk virus in groundwater can remain detectable for over 3 years and can remain infectious for at least 61 days. 13 study subjects were challenged at different time points with groundwater spiked with the prototype human norovirus, Norwalk virus. Norwalk virus spiked in groundwater remained infectious after storage at room temperature in the dark for 61 days (the last time point tested).
Assessing organic pollutant risks in surface waters
A new approach to assessing the risk posed by 500 organic chemicals potentially found in the surface waters of river basins across Europe has been developed and used in a study
. It allows pollutants of concern, including emerging substances, to be identified and prioritised by Member States for monitoring and action as required by the Water Framework Directive.
The study showed that around 74% of the 44 chemicals that were identified as being potentially high and very high risk were pesticides, a result which does not correspond with the EU-wide priority substances currently listed in the WFD. This is potentially alarming, given the strict risk assessments required before pesticides can be approved for market use. The study also reveals that about one third of the 33 priority substances listed in the WFD do not pose a risk in the waters studied in this research.
Phosphate dosing reduces copper in drinking water
Work recently published
has shown that dosing of phosphate to control plumbosolvency also effects significant reduction of copper levels in both drinking water supplies and sewage.
Event detection software
Leak detection and location
A new report and guide for the detection of water pipe leaks has been published by UKWIR - "A SURVEY OF PRACTICES FOR THE DETECTION AND LOCATION OF LEAKS". This new 77 page report
collates the practical experience of 9 UK Water Companies. It provides a software tool to guide the engineer towards the most appropriate method providing a banded score for Equipment / Technique selection.
DWI Annual Report published
The DWI has published its annual report for 2010
which includes regional reports covering six regions of England and additionally Wales which summarise the testing and results of water quality tests, public confidence in drinking water, events and technical audit activity in the region. For the first time it also includes separate reports on Private Supplies for England and Wales publishing details of numbers and types of supplies, a summary of monitoring results and case studies.
Recovering energy from pressure reduction.
Researchers from Bangor University and Trinity College Dublin have identified a way
of using water pressure within the water storage system to generate renewable energy. That energy can then be used by the water industry and sold to the grid. The researchers have been awarded £500,000 in EU funding to investigate and develop small hydropower turbines that could be introduced within existing water treatment systems. These turbines would recover the energy at present dissipated in break-pressure tanks ( no mention is made of recovering energy in relation to PRVs).
Review of Ofwat published
Defra published on 12 July its review of Ofwat
, assessing whether the economic regulator for the water sector is fit for future challenges. The review, led independently by David Gray, was launched by the UK Government and Welsh Government in August 2010 as a ‘health check’ of the existing arrangements ahead of the publication of the UK Government’s Water White Paper later this year and to inform the development of Welsh Government’s future policies on water. The review looked at Ofwat’s role, how it works with others and if its regulatory approach is delivering what the Government and customers expect. The review also considered the arrangements for representing customers in the water sector, currently undertaken by the Consumer Council for Water. The main conclusions are that regulation in the water sector has worked well since privatisation and that major change is not needed to the statutory framework or regulatory landscape; but that to achieve continued success, Ofwat needs to see through the changes it has embarked on to reduce the burden of regulation it imposes on the water industry and work constructively with the other organisations in the sector. The review team also considered existing and alternative approaches for consumer representation and recommended to the UK and Welsh Governments, that the functions the Consumer Council for Water carries out in protecting water customers be retained preferably within CCWater. The Coalition Agreement committed to reform the water industry to ensure more efficient use of water and the protection of poorer households. UK Ministers will respond to the Review’s recommendations in the Water White Paper to be published later this year. Welsh Ministers will decide on how to respond to the recommendations in due course.
Efficacy of chlorine dioxide (ClO2) against seven species of bacterial threat (BT) agents in water
Testing typical ClO2
doses used in water treatment on two strains of Bacillus anthracis
spores, Yersinia pestis
, Francisella tularensis
, Burkholderia pseudomallei
, Burkholderia mallei
species showed these would be effective against all bacteria tested except B. anthracis
spores that would require up to 7 h with the largest allowable dose of 2 mg l-1
. Other water treatment processes may be required in addition to ClO2>
disinfection for effective spore removal or inactivation. More information
Drought in England
Lincolnshire, Cambridgeshire, parts of Bedfordshire and Northamptonshire, and western Norfolk remain in drought. Anglian Water and Cambridge Water who provide public water supply in this area have said that there is no threat to the public water supply as they have enough water to get through the summer.
Current status can be obtained
on the Environment Agency website.
WHO publishes 4th edition of “Guidelines for Drinking Water Quality”
WHO formally launched the latest edition of its Guidelines for Drinking Water Quality on 4 July 2011 The Guidelines
are now available for download or book order following their global launch at the Singapore International Water Week on 4 July 2011. These Guidelines are the product of systematic revisions over more than five years of extensive consultation with hundreds of experts. This 4th edition expands on key concepts like health-based targets and water safety planning; presents new risk assessments on microbial, chemical and radiological hazards, and addresses emerging issues of public concern like pharmaceuticals in drinking-water
"Super Sand" for Better Purification of Drinking Water
Details have been published
of a simple method to coat sand grains with nanosheets of graphite oxide to increase filtering capacity five-fold when tested for ability to remove mercury and the dyestuff Rhodamine B.
Potential leakage problems on PE distribution systems
A new report published by UKWIR
quantifies the scale of potential leakage problems on existing PE systems and drives improved design and construction methods for installing PE pipes. Analysis of failure data and destructive electrofusion joint test records suggest that 20 percent of electrofusion joints will have a life span considerably less than the 50 year design life
Additionally the report provides key recommendations, a handy reference of installation techniques, guides, training recommendations and specific interviews with Water Company operators.
World’s first commercial forward osmosis plant to be built in Oman
UK-based company, Modern Water plc, has been awarded a contract to build and operate
the world's first fully commercial forward osmosis plant. It is claimed that the plant, which will be in Oman, will achieve significant cost savings, use less energy and be more reliable than conventional methods, particularly when operating in such challenging conditions.
Tool for drought prediction announced
An Australian researcher has developed a tool that measures several water and climatic variables to assess dryness in an area and then uses past circumstances to predict future drought conditions. It is claimed that the tool is capable of forecasting drought conditions
six months in advance.
World Health Assembly adopts Drinking-water, Sanitation and Health Resolution
On 24 May 2011, the 65th World Health Assembly unanimously adopted Resolution 64/24 on Drinking-water, Sanitation and Health, urging Member States, inter alia, to highlight the importance of safe drinking-water, sanitation and hygiene as the basis for primary prevention in national public health strategies and to ensure that these strategies contribute to the achievement of the water- and sanitation-related MDG target and to the progressive realization of the human right to water and sanitation. It requests the Director-General, inter alia, to formulate a new, integrated WHO strategy for water, sanitation and health with a focus on water quality and monitoring issues, and to increase technical assistance for enhanced drinking-water quality management.
This was the first time in 20 years that the Assembly adopted a Resolution specifically addressing drinking-water and sanitation.
E coli die rapidly in contact with copper
Work at Southampton University
to be presented by Professor Bill Keevil at a WHO International Conference on Prevention and Infection Control in Geneva on 30 June shows that on a dry copper surface, 10 million E. coli
bacteria are eliminated within 10 minutes and on a wet copper surface, one could expect a total kill within around 45 minutes. This antimicrobial property is inherent to the metal, and shared with alloys such as brass and bronze. ( However biofilms in water pipes may protect E. coli
from this bactericidal action.
Nitrogen-containing disinfection by-products.
DWI has produced a review
of the current toxicological and occurrence information available on Nitrogen-containing Disinfection By-Products. The review finds that there is a significant lack of data but where data are available the risks to health are not a concern,
Significance of methods and sample volumes for E Coli and Total Coliform measurements
DWI has published results
of a jointly funded project with the US Water Research Foundation. The purpose of the research was to provide new information on the relative merits of the various procedures approved by the USEPA and the Drinking Water Inspectorate for the microbiological examination of drinking water. The study has provided data that indicates methods based on detection of activity of the enzymes β-D-galactosidase and β-D-glucuronidase tend to be more specific, sensitive and accurate than the methods based on lactose fermentation.
Guidelines for communicating about drinking water contaminants
DWI has completed a jointly funded project with the Water Research Foundation, and the US Environmental Protection Agency to provide practical advice, tips and validated content in an easy to use manner for deployment by water utilities. Although the project focussed on the requirements of utilities in the USA it contains useful guidance and toolkits
that can be adapted for use by UK water utilities.
Western Australia to trial water recycling
In view of the water shortage affecting Perth and the south west of Australia the Government has asked for a trial involving the pumping of fully treated reclaimed water into the Gnangara aquifer to be fast tracked. If successful, planned expansion of a current desalination plant could be put off indefinitely. More information
Intellectual Impairment in School-Age Children Exposed to Manganese from Drinking Water
is reported assessing the relations between exposure to manganese from drinking water and children’s intelligence quotient (IQ). The study also examined the relations between manganese exposures from water consumption and from the diet with children’s hair manganese concentration.
The authors conclude that the findings of the cross-sectional study suggest that exposure to manganese at levels common in groundwater is associated with intellectual impairment in children.
Validation of Alternative Methods for the Analysis of Drinking Water and Their Application to Escherichia coli Abstract
Investigations into the latest techniques to meet new lead standard
In December 2013, the regulatory standard for lead compliance will be reduced from 25μg/l to the World Health Organization standard of 10 µg/l. Although water utilities currently implement a range of policies to deal with lead (including phosphate dosing, active and reactive lead pipe replacement, and active renovation (lining) of lead pipes), further action may be required to avoid non-compliance.
WRc’s Portfolio collaborative research project, "Technology Based Solutions for Lead (CP428)", will identify the full range of techniques and applications available for dealing with lead, and identify where various techniques will be most cost-effective. The project will undertake a technical review of available techniques to understand how practical they are to implement, in service performance and life expectancy. The economic argument between (reducing) dosing phosphate and replacement or renovation will then be explored using Whole Life Cost Analysis.
Further details are available from Claire Prescott firstname.lastname@example.org
or telephone +44 (0) 1793 865085 or Andy Russell at email@example.com
or +44 (0) 1793 865130
Ion mobility spectroscopy as a potential tool for on-line monitoring of water and wastewater
WRc has started a new Collaborative Portfolio project, "Evaluation of Ion Mobility Spectroscopy (CP429)", where the objective is to assess the suitability of this technology to water industry applications.
Further details are available from Jörgen Jönsson firstname.lastname@example.org
or telephone +44 (0) 1793 865101
Organic compounds migrating from plastic pipes into water
Polish workers report the presence of a range of organo-metallic and volatile organic compounds in water in contact with PVC and PE pipes
available in Poland.
New WHO Guidance Document on Safe Drinking-water from Desalination
Advances in water treatment technologies have rendered desalination to be an increasingly viable alternative source of drinking-water in many regions facing water scarcity. A new WHO guidance document
has been published for Member States to safely manage a drinking-water supply based on desalination processes. It focuses on the key chemical and microbial risks associated with the process, in the context of the WHO Water Safety Plan framework.
Global Safe Water and Sanitation Needs
A series of four articles published in PLoS Medicine on 9
and 16 November 2010
has highlighted the urgent need for safe and adequate water supplies and sanitation for improving global health. Although tuberculosis, malaria and HIV/Aids are widely perceived as the major international health problems, diarrhoeal illness kills more children each year than these three diseases combined. Even if the WHO Millennium Development Goal is achieved by 2015, on tenth of the world’s population will still rely on water from distant or unprotected sources and one quarter will have no access to even a latrine., An agenda for action is proposed.
Israel to set standard for Magnesium in desalinated water
The WHO has concluded that more evidence is required before a decision can be made on issuing Guidelines on minimum calcium or magnesium concentrations in drinking water
. It considers that for desalinated water stabilization practices should ensure that the overall process does not significantly reduce total intake of nutrients such as calcium, magnesium and fluoride. Based on local circumstances, public health authorities may wish to set a requirement to further modify final drinking-water composition in light of overall mineral nutrition.. An article in HealthStream
reports that Israel has decided to require the addition of 20-30 mg/l of magnesium to desalinated supplies.
Pitting Corrosion of Copper in High-pH and Low-Alkalinity Waters
The USEPA has reported on a study
systematically investigating the effect of water chemistry (pH, sulfate, and alkalinity or inorganic carbon, and orthophosphate) on the nature of copper corrosion, both localized and uniform.
Water quality results show that pitting can be initiated without silica, aluminum, organic carbon, or other water quality variables—variables that have been suggested to be important in pitting or frequently associated with copper plumbing that has failed from pitting corrosion.
Use of Bacteroides phages to detect human contamination of spring waters
Workers in Switzerland have selected different strains of Bacteroides which are specifically susceptible to bacteriophages
present in human or animal faeces. This enables detection of human faecal contamination of springs. However, the practical application of this finding is limited because some specific host strains were restricted to certain geographic regions.
Emergency Water Supply after Disasters
A portable gravity-driven microfiltration unit which produces drinkable water in an emergency has been developed at the University of Kassel, Germany. An article in Water Science & Technology: Water Supply
describes how the unit can provide water for 200–500 people for a period of over many months without any maintenance.
Novel process for pipe cleaning
United Utilities is trialling a pioneering technique developed by Bristol University for cleaning mains by passing a mixture of slushy ice
through the pipes. The mixture picks up sediment such as iron and manganese inside the pipes and is expelled into a tanker for safe disposal. The technique is being trialled by United Utilities in a £1.6 million mains cleaning scheme, having already been trialled by Wessex Water
DEFRA consultation on water affordability.
Defra has published its consultation on measures to assist households who face water affordability pressures and households in areas with particularly high water bills, such as the South West. The consultation, which is open until 17 June 2011, follows publication of the independent review of charging for household water and sewerage services and the pledge made in the Budget to consult on proposals to address water affordability. More Information
Water supply implications of pandemic flu.
reported in the journal Environmental Health Perspectives designed to assess the ecotoxicologic risks of a pandemic influenza medical response concludes that existing plans for antiviral and antibiotic use during a severe influenza pandemic could reduce wastewater treatment efficiency prior to discharge into receiving rivers, resulting in water quality deterioration at drinking water abstraction points.
WHO/UNICEF Joint Monitoring Programme for
Water Supply and Sanitation (JMP)
The report of the first meeting of the WHO/UNICEF Task Force on Monitoring Drinking-water Quality
held in November 2010 has now been published. Although looking at a global perspective there is much in the report of relevance to developed countries such as the UK.
Multiple Barrier Approach in drinking water risk assessment
A paper in press
has the following abstract: A number of existing risk assessment tools make reference to, or incorporate, a Multiple Barrier Approach to drinking water safety. Three waterborne disease outbreaks that occurred in developed nations were used as case studies to test a selected set of risk assessment tools. The outbreaks were used to determine how well the risk assessment tools identify hazards and vulnerabilities associated with different barriers to drinking water contamination.
Electrochemical Multiwalled Carbon Nanotube Filter for Viral and Bacterial Removal and Inactivation
Workers at Yale University have developed a highly effective process for removal of bacteria and viruses
. Using carbon nanotubes in a small bench-scale apparatus they were able to completely remove 107 E.coli
and reduce 106
MS2 bacteriophage by c 4 log. With concomitant low voltage electrolysis 100% removal of the viruses was achieved.
Water Hardness and Cardiovascular Disease
Results of research into the impact of step changes in water hardness in parts of England and Wales over the period 1981 to 2008 on cardiovascular mortality
have recently been published. No evidence of an association between step changes in drinking water hardness or drinking water calcium and cardiovascular mortality was found. The researchers concluded that much larger studies (>500,000 people) would be needed to detect changes of the size indicated by other studies.
Drinking water incidents due to chemical contamination in England and Wales, 2006–2008
A recent paper from the Chemicals Hazards and Poisons Division (CHaPD)
of the Health Protection Agency refers to 82 incidents of chemical contamination of water supplies in 2006 to 2008, with data available for 70 of these. 28 incidents related to private supplies and 22 were due to contamination close to the point of consumption. The remaining 20 incidents related to public water supplies.
Water Safety in Buildings
The WHO has just published a document giving guidance on Water Safety in Buildings
The document is directed primarily to those who design, construct, manage, operate, maintain and regulate building water systems. It is intended to be a useful resource for the development of training and information material. The document is based on the WHO Water Safety Plan framework and as such it will be of interest to the water industry.
Do Free-Living Amoebae in Treated Drinking Water Systems Present an Emerging Health Risk?
A literature review by Thomas and Ashbolt
provides evidence that free-living amoebae can be shown passing through treatment with subsequent multiplication and can consistently be detected in treated drinking water systems around the world. While amoebae consume bacteria, some micro-organisms such as Legionellae spp and Mycobacterium spp are known to be amoeba-resistant. Legionellae spp have been shown able to multiply within some species of amoebae. Work is needed to determine whether amoebae and amoeba-resistant bacteria together in drinking water systems have any impact on human health.
Lack of safe drinking water and sanitation in France.
At least 2 million people in France do not have access to safe drinking water and sanitation according to a report published by the French Water Academy
. and quoted by EMWIS
. The Report, in French, says that drinking water is good in cities but does not meet quality standards in 10% of villages, public sanitation is being improved but sanitation in rural areas is inadequate in almost 50% of cases and about 2.4% of rural households discharge their sewage without treatment