News Items Archive 2017

A study by workers in Leicestershire has evaluated the effectiveness of installing water-saving devices in single-family households and has shown a mean 7% decrease in consumption, explicitly attributable to the efficiency program.

Coliphages have been used as indicators of faecal pollution and a rapid chromogenic method has been developed. A modified strain of E. coli has been created which cannot transport glucuronic acid into its cells but has high levels of β-glucuronidase in its cells. Only when the E. coli cells are lysed by phages is a chromogen-coupled glucuronic broken down producing a blue colouration.

BMAA -- a toxin linked to several neurodegenerative diseases -- is present in high concentrations during cyanobacteria blooms in Lake Winnipeg, report Canadian scientists. Although the abstract gives a link to considerable analytical details no cyanobacterial genera or species are implicated.

The updated Legionella Fact Sheet is a very comprehensive document covering all aspects of Legionella aetiology and disease. In regard to potable water sytems it reaffirms that control of Legionella depends on “ keeping hot and cold water systems clean and either keeping the hot water above 50 °C (which requires water leaving the heating unit to be at or above 60 °C) and the cold below 25 °C and ideally below 20 °C or alternatively treating them with a suitable biocide to limit growth, particularly in hospitals and other health care settings, and aged-care facilities”.

Although not a problem with UK water supplies, inorganic arsenic is naturally present at high levels in the groundwater of a number of countries, including Argentina, Bangladesh, Chile, China, India, Mexico, and the United States of America. Arsenic is one of WHO’s 10 chemicals of major public health concern and in its Guidelines for Drinking Water Quality it recommends a limit of arsenic in drinking-water of 10 μg/L

42 drinking water–associated^† outbreaks were reported, accounting for at least 1,006 cases of illness, 124 hospitalizations, and 13 deaths. In 41 of these at least one aetiological agent was identified. Of these 24 were due to Legionella, 8 to Giardia and/or Cryptosporidium. 4 were associated with chemicals or algal toxins. Other agents identified were norovirus and Campylobacter.

UKWIR has published a report on a project which has produced a ‘Guidance Manual’ which presents a critical review of water companies’ use of GAC (and ozone) over the past 20 years to identify best practices, It also includes a report ‘Review of emerging adsorption media and advanced oxidation processes’, which identified 26 technologies and determined whether these technologies could provide a cost-effective solution to water quality issues.

A very interesting paper published in the USA considers the health implications for the 44.5 million US residents dependent on private water supplies. These supplies are not covered by the Safe Drinking Water Act. The paper reports on the outcome of a summit held in North Carolina on “Safe Drinking Water from Every Tap”. Although the summit considered broader issues it focused on North Carolina, where 35% of the population relies on private wells (the third most of any state), and 3.2 million people live in rural areas (the second most of any state). Furthermore, a history of racial segregation and what is known as “municipal underbounding”—in which expanding cities engulf poor and minority communities without affording them city services—has left many black residents of North Carolina’s periurban areas without access to public water systems, even if adjacent newer neighborhoods are fully connected. The summit agreed that more needs to be done to identify private supplies. (In some ways the US lags well behind the UK and Europe in ensuring the provision of safe drinking water to all and, despite the Constitution, all men are not equal when it comes to public health.)

Results of a study conducted in 1,200 elementary and middle school schools in New York City between 2009 and 2013 has been reported. When water dispensers were placed in school cafeterias, students' consumption of water at lunchtime tripled and was associated with small but significant declines in their risks of being overweight one year later, researchers found. Based on the decision model, the estimated incremental cost of the school-based water access intervention is $18 per student, and the corresponding incremental benefit is $192, resulting in a net benefit of $174 per student. Subgroup analysis estimates the net benefit per student to be $199 and $149 among boys and girls, respectively.

DWI has released its report into distribution of water containing Cryptosporidium to people in North Lancashire in August 2015. United Utilities reported detection of high numbers of cryptosporidium oocysts in water leaving Franklaw Treatment Works on 6 August The Company advised 712,000 consumers to boil water. Although no outbreak of cryptosporidiosis occurred ,several deficiencies in the management of Franklaw Treatment Works were identified and United Utilities pleaded guilty to supplying water unfit for human consumption. And was fined £300,000 with £150,000 in costs.

A study comparing UV-LED at 265 and 280nm separately and in combination with Low Pressure UV for inactivation of E.coli concluded that no synergic effect for disinfection was observed from the combination of 265 and 280nm LEDs. 265nm LEDs had no different reactivation performances than LP UV, while 280nm LEDs could significantly repress photoreactivation and dark repair at a low irradiation intensity of 6.9mJ/cm². Furthermore, the UV-induced damage of 280nm LEDs was less repaired.

Three sets of old cast iron pipe section named BP, SP and GP were excavated, transporting blend water, surface water and groundwater, respectively. Surface water pipe was more corroded than blended water and groundwater pipes and Cl⁻ and SO₄²⁻ accelerated but alkalinity and calcium hardness inhibited iron release. Dissolved oxygen consumption was highly consistent with iron release.Water quality significantly influenced bacterial community in corrosion scales.

The Journal of Water and Health has now extended its support of Open Access by making its archives after 2 years open access.

Approximately 44.1 M people in the U.S. use water from domestic wells. A recent study suggests that of the 44 million population in the US using water from private domestic wells, 2.1 million use wells with a predicted arsenic concentration >10 μg/L. (There is no reason to believe this is fake news nor that there are alternative facts!)

The above document has been published as an aid to the development of Water Safety Plans in particular in South East Asia although its content is more genearlly applicable.

A multi-agency project involving EPA, NASA, NOAA, and USGS, uses historical and current satellite data to provide an early warning indicator system for harmful algal blooms in U.S. freshwater systems. Since the project’s inception in October 2015, CyAN imagery has been used to detect algal blooms in Ohio, Florida, California, Vermont, New Hampshire, Massachusetts, Connecticut, and Rhode Island, before traditional monitoring efforts alerted watershed managers.

A recent study evaluated the costs of a waterborne outbreak of Cryptosporidium hominis infection in Ireland in 2007. A boil water notice was in place for 158 days that affected 120,432 persons residing in the area. The cost of the outbreak was estimated at >€19 million (≈€120,000/day of the outbreak). This study highlights the economic need for a safe drinking water supply.

USEPA has opened a test bed at the Department of Energy’s (DOE) Idaho National Laboratory (INL), which replicates a section of a typical municipal drinking water piping system. Using this simulated full-scale distribution system allows for injection of contaminants that cannot be tested in operating municipal water facilities. Researchers can then evaluate decontamination methodologies to determine those that are best suited for use by water utilities.

Views are being sought on proposed amendments to the Water Supply (Water Quality) Regulations 2016 (‘public regulations’) and the Private Water Supplies (England) Regulations 2016 (‘private regulations’); known jointly as the drinking water regulations. The changes will only apply to England.

Two modifed cellulose compounds have been shown to be able to remove trivalent and hexavalent chromium from water contaminated with 25mg/l of chromium.

A review of over 100 papers related to biofiltration and DBPs found that biofiltration removes a fraction of halogenated DBP precursors and decreases concentrations of formed DBPs, except for THMs. Varying degrees of nitrosamine control by biofiltration have been reported and operating parameters affect the biofiltration performance.

A recent norovirus outbreak involving 4136 cases in Catalonia, Spain was shown to have an association with bottled water from a source in Andorra used in office water coolers. Although rapid removal of the water from all coolers restricted investigations it was likely that the water was contaminated with 4 strains of norovirus even though the water complied with all requirements of the European Commission directive on the exploitation and marketing of natural mineral waters.

The conventional culural method for detecting L.pneumophila detects a large number of other non- pneumophila legionella. A recent paper shows that incubating the BCYE culture medium at 40°C and raising its pH to 7.3 greatly improves its selectivity. It concludes that BCYE pH 7.3/40 °C can facilitate the enumeration of L. pneumophila and their isolation from premise plumbing systems with culturable L. non-pneumophila spp., some of which, e.g. L. anisa, can be present in high numbers.

A recent review looks at Cryptosporidium and Giardia in water since the 1970's and traces development of water analysis methods from the beginning. It highlights essential features of three phases of sample processing and analysis, compiles major advances in finding Giardia and Cryptosporidium in water and identifies key challenges to improved procedure.

A fascinating review has been published which casts some doubt on the tenet that E.coli in water must be a consequence of faecal pollution. The review notes that some Escherichia populations can survive and grow in environmental conditions for prolonged periods. Environmentally adapted Escherichia strains are indistinguishable from faecally derived strains based on current water quality testing methods and may not indicate the occurrences of recent faecal contamination. Therefore, the presence of environmental Escherichia populations severely confounds the use of this bacterium as a faecal indicator. Based on studies done in the past few decades, the presence of environmental Escherichia is now well recognized. These environmental E. coli may be of animal-origin and have become adapted to their surrounding environments; or may retain the characteristics of their ancestral linage, which was environmental bacteria using soil and sediment as their primary habitat. The review also points out that E coli O157:H7 does not have β-glucuronidase and will not be detected by many current monitoring techniques.

UNICEF and WHO have launched a Target Product Profile (TPP) which identifies the need for better simple methods for detection of E.coli to help guide product developers. The uses for which improved methods are required are given as data collection in household surveys; behaviour change and water safety planning with communities; and on-site or field testing for regulatory oversight or surveillance purposes.The Guide includes acceptable and ideal requirements, and prioritizes the ideal requirements for each use case to help developers make decisions on trade-offs. A Request for Proposals is expected later this year.

WHO has published a guidance describing how to apply appropriate management systems to produce safe drinking-water from municipal wastewater. Information is provided on specific aspects of potable reuse, including the quality and protection of source wastewaters, types of control measure monitoring and public acceptance.

DWI has issued guidance on the implementation of the latest Water Supply (Water Quality) Regulations applicable to England and the equivalent Regulations for Wales.

A recent paper looks at relationships between dissolved organic matter (DOM) optical properties, microbial indicator organisms and trace element concentrations in a drinking water distribution network. The purpose was to assess whether DOM optical properties measured at the tap correlate with, and are potential surrogate indicators of, abundances of microbial indicator species.

The authors conclude that in-situ fluorometers should be capable of sensitively monitoring water quality changes in distribution systems between source and consumers, although issues related to reliability, sensitivity and calibration present technical hurdles worthy of further development and investigation.Trace metals can interfere with spectroscopic measurements in the distribution system and increase detection thresholds for observing significant changes in organic matter quality. It is therefore important to consider trace metals when investigating DOM fluorescence as a potential tracer of contamination in unfamiliar networks.

WHO has launched an interactive, web-based, knowledge-transfer platform offering online courses to improve the response to health emergencies.

A recent literature review finds that biofiltration removes a fraction of halogenated DBP precursors and can decrease concentrations of formed DBPs, except for THMs. Varying degrees of nitrosamine control by biofiltration have been reported.

A group of Chinese and US workers have shown that phages can be adsorbed on to magnetic colloidal nanoparticles which then can penetrate biofilms in a weak magnetic field and infect susceptible bacteria. This gives access to bacteria which are otherwise protected within the biofilm. Images showed they effectively killed E. coli and P. aeruginosa over around 90 percent of the film in a test 96-well plate versus less than 40 percent in a plate with phages alone.

A group of 12 New Zealand and US workers have developed an approach that quickly and cheaply removes more than 99 percent of BPA from water. BPA is an endocrine disruptor which is occurs widely in surface waters. The process uses a catalyst which in conjunction with hydrogen peroxide at neutral pH cause the BPA to assemble into larger units called oligomers, which clump together and precipitate out of the water.

United States workers have shown that when using steam for curing CIPP the ejected steam contained a large range of compounds including hazardous air pollutants, a suspected carcinogen, an endocrine disruptor compound, and others that had limited toxicological data. They note that no precautions are normally taken to minimise workers exposure.As with all good papers it recommends further work.

Workers in Austria have developed a loop-mediated isothermal amplification method for detection of enterococci which enables the efficient screening and testing of water samples in low-resource settings lacking sophisticated laboratory equipment and highly trained personnel, requiring only a simple heating block. The quantitative PCR method used routinely in the USA requires a molecular biology laboratory with expensive instrumentation, in the form of a thermal cycler and the data obtained by qPCR must be analysed using complex computer software and interpreted by trained personnel. The new method requires only a simple heating block and the team suggest the LAMP assay has great potential to be combined with lab-on-a-chip systems in a portable, battery-powered device.

WHO has just published a progress report on achievement with its Sustainable Development goals for water, sanitaion and hygiene. The report finds that in 2015, 29% of the global population (2.1 billion people) lacked safely managed drinking water services – meaning water at home, available, and safe. 61% of the global population (4.5 billion people) lacked safely managed sanitation services – meaning use of a toilet or latrine that leads to treatment or safe disposal of excreta. Data on handwashing were too few to make a global estimate, but in sub-Saharan Africa, 15% of the population had access to a handwashing facility with soap and water.

The 2.1 billion people without safely managed drinking water services includes 1.3 billion people with basic services, meaning an improved water source located within 30 minutes; 263 million people with limited services, or an improved water source requiring more than 30 minutes to collect water; 423 million people taking water from unprotected wells and springs, and 159 million people collecting untreated surface water from lakes, ponds, rivers and streams.

The 4.5 billion people without safely managed sanitation services includes 2.1 billion people with basic services, meaning an improved sanitation facility which is not shared; 600 million people with limited services, or an improved sanitation facility which is shared; 856 million people using unprotected latrines or bucket toilets, and 892 million people collecting practising open defecation.

Once again the Report shows a very high level of compliance and for the first time there were no detections of E coli in any sampkles or water leaving treatment works.

The Inspectorate has developed, and introduced this year, a new measure called the Compliance Risk Index, (CRI). This measures risk calculating a value which takes into account the consequence of failures using the prescribed values in the Regulations, any potential health risks, the population affected and the assessed actions of the company in response. The Inspectorate is developing an Event Risk Index, building upon the principles of the CRI.

Using a multiplex bead-based assay to detect oncogenic viruses in water, Italian workers found widespread viral contamination detected in sewage, river, marine, and pool/spa waters with human papillomavirus as the most frequently detected virus. (it would be interesting to apply this methodology to drinking water samples especially if it could also target norovirus)

Danish students have developed a special bag known as SolarSack that is filled with four liters of water and placed in the sun for four hours. Using UVA and UVB rays, as well as heat from the sun, the water is cleansed of pathogenic bacteria. The user can then drink the water and reuse the bag for water purification.

The method was approved by the World Health Organization which estimates that between 99.9 and 99.999 percent of the pathogenic bacteria in the water die.

When chemicals in the environment are combined together, there is potential for a combined adverse effect, even if each individual component is harmless or present at levels at which adverse effects are not expected to occur. WHO launched on 20 June 2017 a document on mixtures of chemicals in source and drinking water , which acknowledges the number of frameworks, procedures and tools that are being utilized to identify appropriate groupings of chemicals for assessment and to evaluate potential interactions between these chemicals but concentrates on the application and relevance of the WHO (2009) framework. The document is extremely comprehensive and cannot be summarised here.

A recent paper considers published data on the use of silver for drinking water treatment and concludes that while none of the studies alone are definitive, and can't be used to determine a safe level of consumption, it concludes that the balance of evidence suggests there is the chance of damage to DNA.

UV-LED is being deveeloped and may well become a viable alternative to conventional UV lamps. A protocol has been developed as a guideline that allows the operation and control of UV-LEDs in any structure, as well as accurately measuring the UV-LED output. Such information is essential for performing a reliable UV-LED assessment for the inactivation of microorganisms and for obtaining precise kinetic data.

1-yr performance evaluation of a 1-mgd direct potable reuse plant using online data demonstrated consistent pathogen removal exceeding performance and risk goals while QMRA confirmed system resilience to failures of varying duration.By distributing the role of contaminant removal between several processes, a multiple barrier approach reduces the impact of any single process failure thereby reducing the chances of a complete, or catastrophic, system failure. Selecting barriers with different forms of contaminant control—physical, chemical, and biological—also improves the system's ability to mitigate the wide range of potential contaminants. The treatment train demonstrated reliable pathogen control that met or exceeded the risk goals used by the U.S., WHO, Australia, and other countries. By providing protection equal to or greater than conventional drinking water sources, DPR should be considered a viable alternative to supplement existing water supplies.

A recent epidemiological study carried out in Sweden showed a significantly elevated risk of vomiting and acute gastrointestinal illness (AGI) in incident affected areas, compared to reference areas. Risk factors, during the incidents, such as sewage and drinking water pipelines at the same level in the trench, were associated with an elevated risk of AGI and vomiting. Safety measures taken during repair work, like flushing, were also associated with an elevated risk of AGI and vomiting.

A detailed study has been published of how much ( little?) students understand of how drinking water reaches the home and wastewater leaving the home is treated. Although the study was carried out in Indiana similar results would be likely to be applicable in many developed countries. The paper is worth reading in detail. When c.450 students were asked to draw diagrams of water treatment and sewage disposal 29% did not draw a water treatment plant and 64% didn't draw a watewater treatment plant.

1 in 5 students showed wastewater being directly returned to the river.

A useful guide to water deregulation in England and Wales has been published. FWR does not endorse the guide nor the services of its producer but simply draws attention to its availability.

Work on endocrine disruptors has concentrated on17β-estradiol (β-E2) and 17α-ethinylestradiol, due both to their prevalence in the environment and strong estrogenic potency. A third steroid, estrone (E1), also can occur at high concentrations in surface waters but generally has been of lesser concern due to its relatively lower affinity for vertebrate estrogen receptors. Lab studies demonstrated that E1 can be readily converted to β-E2 by fish and the authors consider that the two steroids perhaps should be considered equivalent in terms of their potential ecological hazard.

Chemosensors operate according to physical principles, without sample collection (online), and are capable of supplying parameter values continuously and in real-time . A recent review paper contains a comprehensive survey of existing and expected online monitoring technologies for measurement/detection of pollutants in water. The state-of-the-art in online water monitoring and contaminant warning systems is presented.

The USEPA recommends use of qPCR for detection of enterococci while the UK “The Microbiology of Drinking Water (2012) -Part 5” only covers cultural methods for enterococci. A recent paper describes a novel screening method for the molecular detection of Enterococcus spp. by loop-mediated isothermal amplification (LAMP). This procedure allows molecular diagnostics with simple or no instrumentation and is equally sensitive and even more specific than the qPCR assay.

Culture methods for Legionella take several days while qPCR-based methods are also slow, requiring at least a day from sample to result, albeit mainly due to the need for sample transport to a centralized laboratory. A method has been developed for L. pneumophila concentration and detection with live/dead differentiation under field conditions. Using an on-filter direct amplification L. pneumophila could be detected in 1–2 h at ∼1 cfu/100 ml of tap water.

A group of mainly Czech workers studied a groundwater site polluted mainly by recalcitrant psychopharmaceuticals and monoaromatic hydrocarbons, such as benzene, toluene and chlorobenzene. Employing an advanced oxidation technique of UV radiation with hydrogen peroxide dosing in combination with simple aeration pretreatment they showed that UV/H2O2 was an efficient and necessary step for degradation of the pharmaceuticals while the monoaromatics were already removed during the aeration step.

A team of mostly US based researchers has developed a metal-organic framework (MOF) material that has a steep increase in water uptake over a narrow relative humidity range range to harvest water, using only ambient sunlight to heat the material. They obtained 2.8 liters of water per kilogram of MOF daily at 20% RH.

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.

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 and 2)

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.

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.

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)

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.

A study by chinese workers showed backwash recycling caused increases of turbidity, total solids, ammonia nitrogen (NH₃-N), permanganate index (COD_Mn), 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.

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.

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.

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.

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.

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.

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.

Legionella pneumophila 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 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 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)

WHO has recently published new or revised background documents for selected chemical hazards in drinking-water, which informed the development of the recently published first addendum to the fourth edition of the WHO’s GDWQ. These chemicals include (use hyperlink for more information): barium; bentazone; chlorine dioxide, chlorate and chlorite; dichlorvos; dicofol; diquat; lead; MCPA; nitrate and nitrite; and perchlorate.

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.

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”)

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

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, Campylobacter, and rotavirus.

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.

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.

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.

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.

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.

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.

EDIE has produced a useful free water retail competition guide outlining new legislation which comes into force on 1st April 2017.

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.

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)

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.

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.