News Items Archive 2016

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.

Laboratory studies 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)

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).

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 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.

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.

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.

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.

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.

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.

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.

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)

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.

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 to:

1. overview the European policy in the water field;
   
   
2. briefly describe the most commonly used conventional and advanced treatment processes to remove micropollutants;
   
   
3. 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
   
   
4. 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.
   
   

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.

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.

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.

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.

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.

Media reports 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.

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.

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.

DWI has recently issued Guidance on implementing the Water Supply (Water Quality) Regulations in England and Wales and Updated guidance on the use of ultraviolet (UV) irradiation for the disinfection of public water supplies.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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⁺/Zn²⁺) 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.

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.

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.

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.

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.”

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.

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).

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.

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.

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 Report) (DWI Guidance)

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.

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).

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.

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.

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.

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.

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 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.

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 CFU mL⁻¹ to 4 × 10⁵ CFU mL⁻¹ within 5 min and 4 × 10⁴ CFU mL⁻¹ to 400 CFU mL⁻¹ within 60 min.

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).

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.

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%.

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 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.

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)

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.

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.

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.

A recent study in the USA provides evidence of nitrogen accumulation in soils. Using long-term soil analysis data and mathematical modelling it concludes that even with cessation of application of nitrogen fertiliser it would take 35 years for a 99% reduction of the soil nitrogen.

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.

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.

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.

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.

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.

A pilot plant study compared hollow fibre ultra(UF)- and nano(NF)-filters for removal of naturally occuring organic matter (NOM) from 3 different surface water surces. Measuring both u-v absorbance (UVA) and total organic carbon (TOC). UF achieved retention comparable to traditional flocculation and sedimentation steps, while NF achieved even better removal of NOM.

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.

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.

In preparing for the 5th edition of the Guidelines for Drinking-water Quality (GDWQ), the Barium, Chlorine dioxide/chlorate/chlorite and Dialkyltin background documents for development of the GDWQ have been revised while a background document on Perchlorate has been developed. Comments are welcome and should be sent to gdwq@who.int by 19th February 2016.

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

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.

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/H₂O₂ 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/H₂O₂ among the three pesticides.

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.

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.

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.

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.

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.

French workers 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.

A paper by Korean workers compares GAC., GAC + O₃ and GAC + O₃ + H₂O₂ 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 + H₂O₂ + GAC process was determined to be the optimal system for removing NOM and taste and odour compounds.

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.