News Items

DWI review of freeze - thaw event March 2018. (Posted 20/06/2018)
DWI has reported on the Companies' actions in handling the widespread freeze/thaw event in March 2018. It concludes that a number of companies failed to submit their final report by the date requested, and it was necessary for the Inspectorate to request a considerable amount of further data and information from most companies which was missing from the final reports. However, some companies were unable to identify root causes of inability to maintain supplies and the Inspectorate considers this response to be inadequate, and an unsustainable position for those individual companies. The procurement of sufficient emergency supplies of drinking water was clearly a challenge for some companies, and had the severe weather lasted for longer than it did, the abilities of some companies to provide sufficient alternative supplies to consumers could have been severely compromised. The report imcludes a number of recommendations.

Network and Information Systems (NIS) Regulations 2018. (Posted 20/06/2018)
DWI has published guidance on the requirements placed on Water Compaanies by the implementation of the Network and Information Systems (NIS) Regulations 2018 which came into force in May 2018. These Regulations relate to the security of information and network management against cyber attack.

Benefits of drinking water Fluoridation (Posted 20/06/2018)
A recent US study confirms a substantial caries-preventive benefit of fluoridated water supplies for U.S. children and that the benefit is most pronounced in primary teeth.

Induction of Escherichia coli into a Viable but Non Culturable (VBNC) state through chlorination/chloramination (Posted 15/06/2018)
Workers in China have shown that E.coli can become VBNC after treatment with chlorine and chloramine. At concentrations of 1, 2, 3, and 4 mg/L, the counts of culturable E. coli cells decreased from 106 CFU/mL to 0 CFU/mL at 5–60 min post treatment. Meanwhile, viable cell counts were still approximately 103–105 cells/mL TheVBNC cells are capable of resuscitation given the right conditions. ( if the same can be shown to be true for bacterial pathogens this could be significant)

Warning of future water deficits. (Posted 15/06/2018)
A recent Environment Agency report suggest that if no action is taken to reduce demand and increase supply of water, most areas will not meet demand by the 2050s under high greenhouse gas emissions and high population growth scenarios .Even low population growth and modest climate change scenarios suggest significant water supply deficits by the 2050s, particularly in the south-east. ( where Government plans major future growth) Substantial volumes of water are lost during treatment and in people's homes. In total, one-third of water taken from the natural environment is wasted either through leaky pipes, losses in treatment or in the home

Lead in tap water in schools and large buildings. (Posted 15/06/2018)
A total of 130 outlets (fountains, bathroom and kitchen taps) were sampled for dissolved and particulate lead as well as copper. Sampling was conducted at 8 schools and 3 institutional (non-residential) buildings served by municipal water of varying corrosivity, with and without corrosion control (CC), and without a lead service line. In first draw samples after overnigh stagnation higher concentrations were observed in schools with corrosive water without CC (0.9–201 μg Pb/L, median: 14.3 μg Pb/L), Lead concentrations were <10 μg Pb/L in all samples following 5 min of flushing. However, after only 30 min of stagnation, first draw concentrations increased back to >45% of values in 1st draw samples collected after overnight stagnation. Concentrations of particulate Pb varied widely (≥0.02–846 μg Pb/L) and Pb levels across outlets within the same building varied widely (up to 1000X) especially in corrosive water (0.85–851 μg Pb/L after 30MS) confirming the need to sample at each outlet to identify high risk taps.

Based on the much higher concentrations observed in first draw samples, even after a short stagnation, the first 250mL should be discarded unless no sources of lead are present .Results question the cost-benefit of daily or weekly flushing as a remediation strategy.

Identification of microplastics using Raman spectroscopy. (Posted 15/06/2018)
A review of microplastic pollution considers that Raman spectroscopy is the method of choice for identifying microplastics ( < 20 μm ). It discusses drawbacks and solutions to overcome them as well as non-conventional techniques which might permit real-time monitoring. (There is currently great interest in microplastics and studies have shown bottled waters to have higher levels than tap water. There is at present no evidence that microplastics in drinking water present any health risk)

Application of a salivary immunoassay in a prospective community study of waterborne infections (Posted 12/06/2018)
A study was carried out in a city in Massachusetts which used a microbiologically contaminated river as its water source, during summer-early winter periods before and after construction of a new drinking water treatment plant. The study used salivary antibody immunoassay and demonstrated significant associations between gastrointestinal symptoms and Cryptosporidium and norovirus infections, and between water-related exposures and Cryptosporidium infections. Among individuals who used home water filters, associations between non-boiled tap water consumption and Cryptosporidium immunoconversion were not significant before and after new plant construction.

Treated wastewater for aquifer recharge (Posted 12/06/2018)
Pages 14 to 16 of the latest edition of “Water Reuse and Desalination”carries an interesting account of potential use of wastewater treated to meet drinking water standards to recharge an aquifer used as a drinking water source.

Flow cytometric investigation of Slow Sand Filter function. (Posted 30/05/2018)
Swedish workers studied flow cytometric profiles of new and old established slow sand filters before and after scraping . The performance of an established SSF was stable: total organic carbon (TOC), pH, numbers of heterotrophs, coliforms, E. coli, and FCM bacterial profile were unaffected by scraping. However, the performance of two newly-built SSFs containing new and mixed sand was compromised. This suggests that the impact of the surface biofilm on effluent water is greater when the deep sand bed biofilm is not established.

Impact of UVA pre-radiation on UVC disinfection performance. (Posted 30/05/2018)
The disinfection performance of a novel sequential process, UVA365nm LED followed by UVC265nm LED (UVA-UVC), was evaluated. The results revealed that the responses of different E coli strains to UVA-UVC varied. While inactivation of 3 strains was increaased by UVA a fourth strain became less inactivated. The study discusses the biochemical mechanisms at play and postulates reasons for the different results. (It also emphasises the danger of extrapolating experimental results from one strain of an organism to the species in general).

Cyanobacteria link to Alzheimer's disease hypothesis not supported. (Posted 25/05/2018)
The hypothesis that a causal link existed between exposure to the nonprotein amino acid BMAA (β-amino-L-alanine) and a number of human neurodegenerative diseases including Alzheimer’s Disease, has been widely publicised. It was reported that BMAA was synthesised by many freshwater and marine cyanobacterial species, and that it could be concentrated through the food chain, leading to widespread human exposure to this toxin via food, drinking water and recreational water. A recent thorough review concludes that the hypothesis of a causal BMAA neurodegenerative disease relationship is not supported by existing data.

Fluoridation recommended in Australia. (Posted 25/05/2018)
The Australian National Health and Medical Research Council having reviewed all recent data concludes that drinking water fluoridation has positive health benefits and the numerous claims of associations between fluoridation of water and a range of health problems are unsupported. Levels of dental fluorosis are not higher in areas with fluoridated water.

Drinking Water associated disease outbreaks in USA 2013-4 (Posted 25/05/2018)
42 outbreaks were reported leading to 1006 cases and 13 deaths. 57% of outbreaks and all deaths were due to Legionella, Eight outbreaks caused by two parasites resulted in 289 (29%) cases, among which 279 (97%) were caused by Cryptosporidium, and 10 (3%) were caused by Giardia duodenalis. Chemicals or toxins were implicated in four outbreaks involving 499 cases, with 13 hospitalizations, including the first reported outbreaks (two outbreaks) associated with algal toxins in drinking water. The largest reported outbreak was of 369 cases of acute gastrointestinal infectio and 13 hospitalisations associated with contamination of a community/municipality water supply with the chemical 4-methylcyclo-hexanemethanol (MCHM). The contamination was caused by failure of a chemical storage tank in a facility located next to a river, only a short distance upstream of a drinking water intake.

Association Between Perceptions of Public Drinking Water Quality and Actual Drinking Water Quality. (Posted 25/05/2018)
A study in Newfoundland involving 100 householdsin each of 45 communities concluded that the majority of the respondents (>56%) were either completely satisfied or very satisfied with the quality of drinking water. Older, higher educated and high-income group respondents were more satisfied with water quality than the younger, less educated and low-income group respondents. The study showed that there was no association with public satisfaction level and actual water quality of the respective communities.

Economic Assessment of Waterborne Outbreak of Cryptosporidiosis (Posted 25/05/2018)
An outbreak of cryptosporidiosis in Western Ireland in 2007 has been estimated as costing over €19 million. Because of the difficulty in installing additional treatment advice to consumers to boil water was in place for 158 days.

More DBPs (Posted 21/05/2018)
A recent paper describes how UV and hydrogen peroxide can react with phenolic compounds in water to form toxic enedials and oxoenals. In addition to raising concerns about potential health risks of oxidative water treatment,the authors suggest the potential for formation of these toxic compounds in sunlit surface waters, atmospheric water, and living cells.

Mainstreaming Potable Water Reuse in the United States (Posted 21/05/2018)
The USEPA in collaboration with others has published a very detailed and informative report on a workshop held in 2107which considered the institutional hurdles to potable reuse. Despite the many successful schemes in operation in the US and worldwide there is still resistance to such schemes.

Global overview of national regulations and standards for drinking-water quality (Posted 18/05/2018)
WHO has published a fascinating review of regulations and standards for drinking water quality in 104 countries and territories, representing c 89% of the world's population, and their comparison with WHO Guidelines on Drinking Water Quality or WHO Health-based Values. The review shows a wide range of values and parameters being regulated for the different countries and frequent instances of values set higher than WHO guidance. For microbiological parameters only 1 country has not set a value for E.coli while at the other extreme only single countries have set limits for one or more of amoeba, Vibrio cholera, free living organisms, helminths, Legionella, nematodes, parasites and plankton. Several countries have set values for parameters such as total heterotrophic bacteria, hardness or potassium for which WHO has considered it is not appropriate to set a value, while lead is one of only three parameters for which all 104 countries have set a value.

Radiation for removing organic contaminants (Posted 09/05/2018)
A recent review paper presents radiation processing as a promising approach for removing organic contaminants, providing strong evidence of its efficacy, efficiency, safety, and feasibility. Focusing particularly on the use of electron-beam (EB) processing for the removal of organic pollutants from waste water and drinking water, the researchers present a compelling picture, relevant to stakeholders involved in water treatment and management. In recent years, EB accelerator technology has developed significantly, and its lower running costs and increased ease of operation make it a practical choice for water treatment applications. EB irradiation offers several advantages over other water treatment technologies: no chemical additives are required, no by-products are created, no lengthy exposure times are necessary and workers are not required to handle any highly reactive liquids or gases.

On-site non-potable water systems. (Posted 26/04/2018)
A recent report, “Making the Utility Case for On-site Non-potable Water Systems”, catalogues the benefits, lessons learned, and key strategies for implementation of on-site non-potable water systems. The report includes interesting case studies. The report claims that these systems can save 25% of potable water use in domestic premises and 75% in commercial buildings.

NDMA formation in chloramination. (Posted 26/04/2018)
N-nitrosodimethylamine (NDMA), a probable human carcinogen disinfection by-product, has been detected in chloraminated drinking water systems. Laboratory tests using 5 different potential NDMA precursors showed NDMA formation was faster and higher as dichloramine concentration increased.

DBPs and health impact on pregnancy outcomes. (Posted 26/04/2018)
Epidemiological studies have found that maternal exposure to disinfection by-products (DBPs) may lead to adverse pregnancy outcomes although the findings tend to be inconsistent. A meta-analysis of 32 studies found 12 of these reported a statistical association between maternal exposure to DBPs and adverse pregnancy outcomes. A maternal exposure to trihalomethanes (THMs) shows an increased risk of small for gestational age (SGA) and slightly increased risk of pregnancy loss. The review not unsurprisingly concludes more research is needed.

Lead in drinking water in schools and large buildings (Posted 26/04/2018)
A Canadian study found first draw lead levels in schools with corrosive water without corrosion control (CC) of 0.9–201 μg Pb/L, (median: 14.3 μg Pb/L) while levels in schools with CC ranged from 0.2 to 45.1 μg Pb/L (median: 2.1 μg Pb/L). Partial flushing (30 s) and full flushing (5 min) reduced concentrations by 88% and 92% respectively for corrosive waters without CC. Lead concentrations were <10 μg Pb/L in all samples following 5 min of flushing. However after only 30 min of stagnation, first draw concentrations increased back to >45% of values in 1st draw samples collected after overnight stagnation. Results question the cost-benefit of daily or weekly flushing as a remediation strategy. As such, current regulatory requirements may fail to protect children as they may not identify problematic taps and effective mitigation measures.

PAC dosing for taste and odour removal. (Posted 18/04/2018)
Australian workers have developed a powdered activated carbon dosage prediction model which can be used for rapid dosage assessment.

WHO review of alternative disinfectants. (Posted 18/04/2018)
WHO has published a series reviewing the state of the knowledge on the application, efficacy and toxicity of bromine, iodine and silver as drinking-water disinfectants.

Evaluation of corrosion indices (Posted 11/04/2018)
A recent paper evaluated the relevance of 10 known corrosion indices according to their estimate of corrosion rate and iron particle release for 20 different water qualities. None of the indices properly predicted the level of risk associated with each water and corrosion and particle release were not correlated. Two novel indices were developed to predict the corrosion and particle release risks independently of each other.

Human infectious Cryptosporidium risk in drinking water supply catchments (Posted 11/04/2018)
An Australian paper reports on analysis of 962 samples, taken during rainfall run-off conditions from 9 water supply reservoir locations, for Cryptosporidium oocysts. 23 Cryptosporidium species were detected, the most common being C. parvum which was found in 23% of samples. Average infectivity of isolates was 18% with a maximum of 65.4%. The authors suggest that inclusion of measured infectivity and human pathogenicity data into a quantitative microbial risk assessment (QMRA) could reduce the source water treatment requirements by up to 2.67 log removal values.

Water fluoridation found safe and effective (Posted 09/04/2018)
Public Health England has published a report comparing data on the health of people living in areas of England with differing concentrations of fluoride in their drinking water supply. The report concludes that water fluoridation is an effective and safe public health measure to reduce the frequency and severity of dental decay, and narrow differences in dental health between more and less deprived children and young people. It says that there is no convincing evidence of higher rates of hip fracture, Down’s syndrome, kidney stones, bladder cancer, or osteosarcoma (a cancer of the bone) due to fluoridation schemes. Although Dental fluorosis, at a level that may affect the appearance of teeth, was observed in 10% of children/young people examined in 2 fluoridated cities , there was no difference between children and young people surveyed in fluoridated and non-fluoridated cities when asked about their opinion on the appearance of their teeth.

Plastic particles in bottled water (Posted 09/04/2018)
There has been considerable media interest in the findings of a non-peer reviewed paper, issued only as a press release and not in a recognised journal, which found traces of plastic particles in 93% of 259 bottles of packaged drinking water. The average count of plastic particles was 335/litre.

Recycled water scores best in taste test. (Posted 07/04/2018)
In a study in water stressed California water preferences of 143 participants for one name-brand bottled water, one groundwater-sourced tap water, and one indirect potable reuse (IDR) water were assessed. (The IDR water is derived from groundwater into which reverse osmosis treated wastewater has been introduced). In blind tastings with 143 participants, the more nervous, anxious people in the study expressed the preference for IDR and bottled water, and were more negative about the more mineral-rich tap water. People more open to new experiences liked the three samples about the same.

Heavy metal removal from water (Posted 07/04/2018)
A recent paper describes the development of a cheap, water stable metal–organic framework/polymer composite, Fe-BTC/PDA, that exhibits rapid, selective removal of large quantities of heavy metals, such as Pb2+ and Hg2+, from real world water samples The material is further shown to be resistant to fouling when tested in high concentrations of common organic interferents, like humic acid, and is fully regenerable over many cycles. The authors suggest that this new material could become highly influential for in-home or wastewater treatment technologies, particularly in the event of an impending water crisis.

Detection of cyber attacks in water systems (Posted 07/04/2018)
Water systems are increasingly dependent on computerised systems and are therefore vulnerable to cyber attack. A competition (batadal) was organised to compare the performance of algorithms for the detection of cyber attacks in water distribution systems. Details of the winning algorithm have been published.

Detection and prevalence of human enteric viruses in water (Posted 07/04/2018)
Anyone interested in water virology should not miss a recent Open Access paper which comprehensively summarises recent progress on research regarding waterborne human enteric viruses. It reviews methods for concentrating and detecting viruses in water and compiles existing data on abundance and genetic diversity of viruses in water. It also discusses the use and importance of process controls in evaluating the efficiency of virus recovery and level of inhibition during the detection process.

Double disinfection, and UV-LEDs for drinking water treatment (Posted 28/03/2018)
A new study shows that a combined disinfection treatment with chlorine and UV radiation can be highly effective in water disinfection. Chlorination followedby UV was more effective against a range of bacteriophages than either treatment alone. The same study reports that UV LEDs were effective against the same bacteriophages.

Fast-acting antidote in sight for cholera epidemics (Posted 28/03/2018)
Workers in Sweden have shown that some fucose derivatives can block receptors for cholera toxin in the gut. They suggest that it could be possible to produce a drinkable protection that can be distributed during an ongoing cholera epidemic to reduce its spread.

Online fluorescence spectroscopy for the real-time evaluation of the microbial quality of drinking water. (Posted 12/03/2018)
A consortium of workers from UK water companies and academics carried out a study which concluded that fluorescent dissolved organic matter (DOM) is strongly correlated with E. coli and total bacterial cell counts. It is also superior to turbidity as an indicator of microbial water quality. They conclud3e that despite some limitations online fluorescent DOM sensors are a better indicator of the microbial quality of untreated drinking water than turbidity.

Direct pathogen detection in contaminated surface water (Posted 12/03/2018)
Workers in the USA studied a watershed in which fecal coliforms have improved substantially in the watershed since its listing as a 303(d) impaired stream in 2002 and are now near United States recreational water criterion standards. Using molecular techniques they were able to detect viruses (bocavirus, hepatitis E and A viruses, norovirus, and enterovirus G), bacteria (Campylobacter spp., Clostridium spp., enterohemorrhagic and enterotoxigenic Escherichia coli, uropathogenic E. coli, Enterococcus faecalis, Helicobacter spp., Salmonella spp., and Vibrio spp.), and eukaryotes (Acanthamoeba spp., Entamoeba histolytica, and Naegleria fowleri. Comparison of the stream microbial ecology with that of sewage, cattle, and swine fecal samples revealed that human sources of fecal contamination dominate in the watershed.

Simple arsenic sensor (Posted 06/03/18)
A hand-held sensor to measure arsenic levels in water has been developed by researchers at University College London (UCL) and Imperial College London, with funding from BBSRC. The sensor uses a modified arsenite oxidase enzyme from E.coli. The small, sensitive and accurate sensor produces an immediate measure of the arsenic level in water, at a cost of less than $1 per test. This makes it suitable for testing multiple sites in rural areas in low and middle income countries, where the problem of arsenic poisoning from contaminated drinking water is greatest, and potentially saving lives. (patent application)

Efficiency programmes best strategy for water security (Posted 06/03/2018)
Combatting water shortage such as is affecting Capetown in South Africa by capital works takes a long time and cannot solve immediate crises. A recent article in Source magazine argues that water efficiency measures can prove a more immediate solution. On the basis of cubic metres gained, water efficiency programme investments are much cleaner, cheaper, faster and fairer than building new supplies. Australia learned this lesson during its 10-year Millennium Drought. Building new dams would have cost US$1,370 per Megaliter (/Ml) of water delivered. By contrast, the same Ml could be added by plugging leaks in the network at a cost of only US$365/ Ml and the country gained additional supplies by replacing high flow plumbing fixtures for just US$454/ Ml, less than a third of the cost of developing new supply.

ATP for rapid water quality assessment (Posted 19/02/2018
While FWR does not endorse commercial products, readers may be interested in a new test which can indicate the microbial content of a clean water in 3 minutes. Water is filtered then any retained microbial cells are lysed and the ATP released is estimated using the luciferin/luciferase procedure. The same company offers a kit for determining coliforms and E.coli within 24 hours.

Legionella outbreak attributed to change in water supply source (Posted 19/02/2018
A report on the Legionnaires disease out break in Flint, Michigan attributes the outbreak to change of water supply source to the Flint River and consequent reduction in chlorine levels. The majority of the Legionalla isolated from premises ( 16 of 18) were serogroup 6, which is not detected by the widely used urine test for legionella.

Solar powered desalination (Posted 19/02/2018)
Researchers in Spain have developed a stand-alone system for desalinating and treating water through electrodialysis. The system is directly powered by solar energy and can be applied in off-grid areas. The research group already has a pilot and demonstration plant able to generate a cubic metre of drinking water every day.

Importance of dechlorination of drinking water samples for bacteriological analysis (Posted 19/2/2018)
Results have been published of a simple laboratory and field test study which confirm the importance of sodium thiosulphate dechlorination of bacteriological samples. All samples held without sodium thiosulfate had lower bacteria counts than comparable dechlorinated samples. In addition chlorinated water supply samples held without sodium thiosulfate had an 87.5% false negative rate.

Yorkshire Water to plant 1 million trees (Posted 08/02/2018)
Yorkshire Water has announced plans to plant 1 million trees as part of the creation of the Northern Forest . T he Company says that planting trees in the right place will help to slow the flow of water during potential flood events, mitigate carbon emissions and boost wildlife. Although not claimed, the trees could have a beneficial effect on water quality particularly in upland reservoirs.

Novel toxicity biosensor (Posted 31/01/2018)
Workers at the University of Bath are developing a novel microbial fuel cell capable of responding to toxicants in water. The device is fabricated by screen-printing carbon-based electrodes onto a single sheet of paper. It is membrane-less, as the paper substrate itself acts as the separator between the two electrodes. The device is fully biodegradable. The device has been evaluated using formaldehyde as the toxicant but it is expected to respond to a range of other toxicants.

Direct potable re-use (Posted 25/01/2018)
A recent review (paper)describes long-term experience of direct potable reuse (DPR) in Windhoek, South Africa (48 years) which shows that treated domestic sewage can be safely and cost-efficiently utilized for potable reclamation (0.72 €/m3). A multiple barrier strategy is employed in order to attain the highest possible safety levels. Although most potable reuse schemes are indirect (IPR) and involve groundwater recharge or reservoir augmentation, the discharge of treated wastewater ro rivers subsequently abstracted for potable treatment has been a longstanding practice. A few other DPR schemes are in existence but invariably involve feeding the treated wastewater to conventional treatment works. DPR is likely to increase as populations increase and WHO has issued guidance for future schemes. (WHO Guidance)

Priming of rapid sand filters to enhance nitrification (Posted 23/01/2018)
Danish workers have shown that nitrifying communities in new rapid sand filters could be enriched by microbiomes from well-functioning rapid sand filters in waterworks and that the enriched nitrifying consortium could be used to inoculate fresh filters, significantly shortening the time taken for the nitrification process to start.

Low Energy Desalination (Posted 23/01/2018)
A recent letter in Environmental Science and Technology Letters describes a novel desalination process for brackish water which has lower energy requirements than conventional techniques. The procedure does not require any regeneration stage but is not suitable for seawater higher salt sourcers such as seawater.

Impact of changing source of water supply – United Utilities, Copeland (Posted 18/01/2018)
DWI has published its assessment of an incident in Cumbria in June 2017 in which large numbers of consumers were concerned by noticeable changes in their drinking water supplies. The area affected was supplied with soft surface-derived water from Ennerdale but in 2009 its licence to abstract was reduced and it became necessary to obtain additional supply. Four boreholes were licenced to provide the additional supplies although these provided much harder water. Commissioning trials of these boreholes were commenced in May 2017. wherupon many consumers began complaining. Although supplies remained safe the Company was remiss in not informing consumers of the changing supply which resulted in widespread concern. The supply was deemed unwholesome as it breached the Taste and Odour requirements of the Regulations. DWI made several recommendations but concluded that enforcement wqs not required at this time.