News Items Archive 2020

This laboratory study showed that Sodium silicate addition while maintaining pH 7.7 lowered lead release. Lead release decreased upon a pH increase to 8.8 with and without sodium silicate.

The USEPA is developing a database which ultimately will cover over 200 potential drinking water contaminants and be usable to identify effective drinking water treatment processes, to plan for future treatment plant upgrades, to provide information to first responders to spills or emergencies, to recognize research needs, to complement literature reviews and literature searches, and to assist regulators. For any selected contaminant there will be an Options for Treatment Processes page, a Properties page, a Fate and Transport page and a References page. On the Treatment Processes page there will be a summary of the effectiveness of the various processes for control of the contaminant

This excellent article looks at the current role of automation in water supply and distribution and the challenges in taking it forward. The author looks back at his predictions in the 1990's and how far many of them have still to be achieved but is still of the opinion that automation can be a tool to realize at least some of these goals.

Monochloramine reduced Legionella, heterotrophic plate counts, Pseudomonas aeruginosa and Vermamoeba vermiformis.with no nitrification or other negative unintended water quality consequences.

The addition of nails to lab scale sand filters resulted in significantly better (p<0.05) bacteria removal for all filter sizes and significantly better (p<0.02) protozoan removal for the bucket-sized filters. Log10 virus removal for all filter types and sizes ranged from <1 to 6.

Soil microbial fuel cells with an anode buried in soild and a cathode exposed to air can generate 0.4 mW of power. Using a series of 64 cells in parallel could produce up to 3 litres of water per day.

A study in the University of Sheffield using a laboratory based full scale DWDS experimental system with HDPE pipework showed that slightly reducing the amount of disinfectant residuals used to maintain clean drinking water could deliver significant improvements to water quality while making drinking water systems more sustainable, High-chlorine concentrations reduced biofilm cell concentrations but selected for a distinct biofilm bacterial community and inorganic composition which led to higher discolouration when flushed. The study yielded much interesting information but it would be premature to change current practice without further data.

When it is necessary to boost disinfection in a long distribution system this study shows that this can be achieved using pre-formed monocchloramine. This study found that the current kinetic model used for drinking water application was not accurate for highly concentrated monochloramine and a simplified kinetic model was developed and successfully used to predict monochloramine stability. Hydrazine, a compound of health concern, might form at high monochloramine concentrations and high pH and needs to be carefully controlled.

This book covers the issues and worldwide solutions of water treatment. It focuses on aspects of detection, identification, and removal methods of waterborne pathogens. It addresses the issues of modern applications of scientific achievements such as biosensors or molecular tools in the detection of pathogens or monitoring the release of resistance genes into the environment.

Chinese workers have shown thatl Low level chlorination of water can result in the survival of E.coli in a viable but non-culturable state with a greater resistance to a range of antibiotics.

This paper proposes that exercises to test preparedness should not simply test responses but should promote a learning environment and incorporate structured training exercises.

Studies on a British distribution system showed that with phosphate dosing, turbidity responses were increased, particularly from cast iron pipes. Differences in the taxonomic composition of both bacteria and fungi were also observed, emphasising a community shift towards microorganisms able to use or metabolise phosphate.

UKWIR held an on-line dissemination of results from a project involving exhuming and analysing test beds of plastic pipes and joints laid over 30 years ago and evaluating the long-term asset performance, the associated risk of asset ageing and the effectiveness of improved electrofusion jointing initiatives. Overall, the likely lifetime of the pipe is substantially higher than the current design life of 50 years which is good news for the industry.

Using the Soil and Water Assessment Tool it is possible to simulate metaldehyde effectively using water industry historical data. Outputs from this research demonstrate the potential application of SWAT in large complex catchments where routine monitoring is in place, but isn’t designed explicitly for the purpose of predictive modelling.

This study showed the survival of a small number of E.coli O157:H7 cells in the VBNC state after boiling for 1 or 10 min or microwaving. Furthermore, the VBNC E.coli O157:H7 cells regained growth at 37° C in culture media containing autoinducers produced by common non-pathogenic E. coli, commonly present in the human intestine, and norepinephrine. This study highlights potential concerns for public health risk management of VBNC E. coli O157:H7 in drinking water disinfected by heat treatment at point-of-use.

Somatic coliphages can be used as indicators of faecal pollution of waters. Bluephage is a novel method which utilises a strain of E.coli which cannot release β glucuronidase except when cells are lysed, which is brought about in this method by phage. The method allows detection of as few as 1 somatic coliphage in under 3.5 h.

While geosmin and 2-methylisoborneol are the most studied earthy-musty odour-causing compounds in water, pyrazine and its alkyl and methoxy compounds possess similar odours. The widespread presence of earthy-musty-sweet pyrazines in source and drinking waters on two continents, their poor removal during water treatment, and ng/L odor threshold concentrations confirm their potential to be T&O issues for consumers.

Raman benchtop setups can be up to a metre long but researchers have designed a system that can potentially replace these bulky benchtops with a tiny photonic chip that can snugly fit within the tip of a finger and is ten times more sensitive.

Studies on a full-scale water treatment plant In Sweden showed that the average removal efficiency of PFASs ranged from 92 to 100% for “young” GAC filters and decreased to 7.0–100% for “old” GAC filters. it was concluded that prolonging the GAC service life by lowering the flow-rates after reaching the treatment goal could lead to a 26% cost-deduction.

Work carried out in Quebec, Canada concluded that within the studied networks, the water requirements for air scouring were approximately 8-fold less than for unidirectional flushing and did not significantly improve the hydraulic capacity of the cleaned pipes. (this is taken from the published abstract but does not seem to be a sensible conclusion)

DWI has isued Information Letter 05/2020 notifying water undertakers of the potential risk of the formation of cyanide above the PCV following chloramination.It requires appropriate monitoring to determine whether any specific works presents a risk. ( no reference is made to cyanogen chloride in this context)

This US study using toxicological assessment indicated that haloacetic acids have an overall greater cancer potency than trihalomethanes. The inclusion of unregulated haloacetic acids in a toxicologically-based framework increased the possibility that a cancer risk assessment for disinfection byproducts will accurately reflect the risk.

In tropical to temperate environments, fecal indicator bacteria (FIB), such as enterococci and Escherichia coli, can persist and potentially multiply, far removed from their natural reservoir of the animal gut. FIB isolated from environmental reservoirs such as stream sediments, beach sand and vegetation have been termed “naturalized” FIB. An additional theory suggests that some “naturalized” FIB diverged from enteric FIB many millions of years ago and are now normal inhabitants of the environment. It has been postulated that these environmental FIB belonging to the genera Escherichia and Enterococcus can be differentiated from enteric FIB by genetic methods.

Three water quality indices previously presented in the literature have been evaluated and used for the first time to assess the water quality of service reservoir designs optimised by different methods. This research is to enable designers to compare designs of service reservoirs that vary spatially and in size with regards to water quality performance and during optimisation procedures.

F-specific coliphages have been proposed as viral indicators of fecal pollution. This study describes a new method designed to exclusively detect F-specific phages in which, when detected, the yellow medium turnsue. As low as one F-specific phage was detected in 3 to 5 hours by this approach and when the sample contained high phage concentrations, results were obtained in less than 3 hours.

This study reports the existence and resuscitation of viable but nonculturable (VBNC) Escherichia coli O157:H7 cells in drinking water induced by the common point-of-use disinfection treatments of boiling or microwaving. This strain of E.coli causes severe disease in humans.

This study on samples from two urbanised Chinese rivers showed that microplastics selectively enriched antibiotic resistant genes (ARGs), and a good-fit correlation between ARG profiles and bacterial community composition was observed.

Workers integrated existing water industry,datasets for the River Medway, uk with the open-access Soil and Water Assessment Tool (SWAT), to establish if these datasets could be used to effectively model metaldehyde in river catchments.. Outputs suggest that SWAT could be applied universally to catchments using existing water industry datasets.

Japanese workers have devised indices for evaluating deterioration of drinking-water distribution pipelines and maintenance management systems for the pipelines. The indices are the percentage of old pipelines, the percentage of ineffective water, change in the number of technical staff per unit length of pipe, and the repair rate of water leaks . Using these indices, the evaluation result for Japan overall was a C (Caution) in terms of deterioration and Downward in terms of maintenance management.

Workers in Canada performed tests in the laboratory on a test loop and found that the ratio between turbidity and suspended solids (TSSC) may vary greatly between samples, up to 10 times during unidirectionalflushing sequences and 20 times during air scouring sequences. Particle origin, flushing method, and sampling time are all factors impacting the turbidity/TSSC ratio. They caution that total suspended solids should not be estimated from a single turbidity reading.

Studies in the USA and China found widespread presence of earthy-musty-sweet pyrazines in source and drinking waters. Their poor removal during water treatment, and ng/L odor threshold concentrations confirm their potential to be T&O issues for consumers

Swedish workers conducted a nationwide register-based prospective study to assess whether gestational exposure to the four most common chlorination by-products [total trihalomethanes (TTHMs)] via tap water was associated with risk of small for gestational age (SGA), preterm delivery, and very preterm delivery. To date, this is one of the largest studies assessing drinking water TTHM-associated adverse reproductive outcomes, covering over half a million pregnancies.

The results of the present study provide the evidence that CBP exposure via drinking water is associated with increased risk of SGA in areas with hypochlorite treatment, but not chloramine, potentially due to CBP formation differences. There was no clear association for preterm or very preterm delivery.

This special edition of Journal of Water Supply: Research and Technology – AQUA includes a collection of papers dealing with advanced approaches on urban water works and water cycle management.

This paper compares elasticity of arteries in consumers receiving soft or hard water. Higher arterial stiffness (low flexibility of arteries) was determined for residents supplied with soft drinking water. The “absolute” difference between the arterial and actual age between the two evaluated groups of residents (soft vs. harder water) was nearly 5 years on average. The higher arterial stiffness and age of residents that consumed soft drinking water indicate the health significance of lower contents of Ca and Mg in drinking water as an environmental risk factor of cardiovascular diseases. Measuring arterial stiffness of residents in the areas supplied with soft drinking water can be used as a non-invasive approach in the prevention of cardiovascular risks.

The literature is awash with papers on all aspects of coronavirus and Covid 19. This literature review helps assess the current knowledge base and summarises the occurrence, persistence and survival data for coronavirus in water. It also considers methods for the recovery of coronavirus from water. It concludes that there is no current evidence that human coronaviruses are present in surface or ground waters or are transmitted through contaminated drinking-water.

Scientists designed a next-generation miniature lab device that uses magnetic nano-beads to isolate minute bacterial particles that cause diseases. The developers say “We can bring this portable device to a lake which has been contaminated by E. coli. We will be able to take a few milliliters of the water sample and run it through our device so the bacteria can be trapped and concentrated. We can either quickly detect these bacteria in the device or release them into certain chemicals to analyze them" (this is not as yet an alternative to conventional bacteriological sampling and analysis.)

This paper demonstrates that average log-reduction characteristically overstates average treatment performance and a technology with better average log-reduction is not necessarily better on average. Using average log-reduction as a default treatment value in QMRA understates risk.

Researchers have called for more research to determine the best ways to keep SARS-CoV-19 out of the water cycle. They also suggest that developed nations should finance water treatment systems in the developing world to help prevent future COVID-19 pandemics.. During a 2003 SARS outbreak in Hong Kong, a sewage leak caused a cluster of cases through aerosolization.

WHO has published advice repudiating several myths regarding COVID 19.

Useful notes from US CDC.

Studies in Germany found Sulfamate occurs almost ubiquitously in major surface waters, mostly derived from discharges from sewage treatment works. Common drinking water treatment techniques, including ozonation and filtration with activated carbon, are not capable of removing sulfamate. About 30% of samples from ground and surface water exceeded the predicted no-effect concentration (PNEC) of sulfamate, and thus effects of sulfamate on the aquatic ecosystem of wastewater-impacted waterbodies in Germany cannot be excluded so far. However toxicological estimations suggest that no risk to human health is expected by concentrations of sulfamate typically encountered in tap water.

Per- and polyfluoroalkyl substances (PFASs) contain bonds between carbon and fluorine atoms considered the strongest in organic chemistry. In the presence of excess elctrons these bonds have been shown to be readily breakable.The workers speculate that in a real water treatment scenario, the excess electrons could come from metal-containing compounds placed in the water under ultraviolet radiation. The electrons from these compounds will interact with the PFA molecules and break them.

This study looked at the risks associated with the direct reuse of microfiltered greywater from bathroom, laundry and kitchen. It concludes that risks were acceptably low except for the reuse of kitchen greywater for crop irrigation.

This paper proposes a framework for assembling a disinfection plan in real-time by (1) partitioning a WDS into a number of district metered areas (DMAs), (2) generating a solution region for each of the DMAs, and (3) assembly of an effective decontamination plan using solution region generated.

Japanese workers have devised indices for evaluating deterioration of drinking-water distribution pipelines and maintenance management systems for the pipelines. The indices are the percentage of old pipelines, the percentage of ineffective water, change in the number of technical staff per unit length of pipe, and the repair rate of water leaks.

WHO is preparing a number of background documents for selected chemical hazards in water. These will inform the development of the second addendum to the fourth edition of the WHO’s Guidelines for Drinking-water Quality (GDWQ). The cyanotoxin background documents will also inform the revision of the Guidelines for safe recreational water environments. The revised background document is ready for review for microcystin. Comments on the background document should be sent to  by 17 April 2020 and can be accessed here.

A study of a global dataset of 9404 published and unpublished groundwater dissolved organic carbon (DOC) concentrations from aquifers in 32 countries across six continents. The study forecasts elevated DOC concentrations because of projected changes in temperature and rainfall due to climate change, as well as increased urbanisation.

By inducing water hammer and using pressure sensors these authors have developed a computational method which can be used in real time on a laptop to locate leaks.

This paper proposes a framework for assembling a disinfection plan in real-time by (1) partitioning a system into a number of district metered areas (DMAs), (2) generating a solution region for each of the DMAs, and (3) assembling an effective decontamination plan using solution region generated. When applied to 3 contamination events the approach significantly reduce the response time; improved the quality of the decontamination plan;, and provided a model for optimizing the resource allocation.

This book, although published in 2012, has much of interest and current relevance. It is now Open Access thanks to a partnersip between IWA and Knowledge Unlatched.

Researchers at the University of Bath have developed a revolutionary desalination process that has the potential to be operated in mobile, solar-powered units. The process is low cost, low energy and low maintenance, and has the potential to provide safe water to communities in remote and disaster-struck areas where fresh water is in short supply.

Unlike the classical desalination process, where water rather than salt is pumped through a membrane,this process pumps salt out of seawater. The process is as yet only at the proof of conceptstage.

This multinational paper shows how in the absence of a policy for substances of emerging concern in groundwater, and in the face of insufficient data, a group of states, agencies and researchers have come together to try and fill this important policy gap on a voluntary basis. It describes the approach that has been developed through a voluntary initiative as part of the EU CIS Working Group Groundwater to establish the voluntary EU Ground Water Watch List.

A multiplex bead-based immunoassay capable of measuring IgG antibody responses to six waterborne pathogens simultaneously in human saliva is described. The assay,, together with the cutoff points established, allowed measurement of immunoprevalence rates and coinfections to six waterborne pathogens among beachgoers in Puerto Rico. Although no of obvious relevance to drinking water,. the technology is capable of more widespread use.

In 2018, the WASH sector was surprised by three new high-quality studies that showed little or no impact of selected WASH interventions on reducing childhood diarrhoea and stunting. Some practitioners, researchers and funders have reacted by questioning the value of investing in WASH compared to other public health interventions and how future WASH implementation can be improved to achieve greater health gains. These studies are not a call to stop working together but rather to programme together more effectively. This paper discusses where approaches to WASH need to be better focussed and suggests that provision of “improved” water and sanitation technologies could only deliver modest health gains,and that more substantial health improvements can only come with entire community coverage with higher service levels.

Meta-analysis of eight studies assessing nitrate in drinking water and CRC supports a health benchmark of 0.14 mg/L. The study concludes that 2,300 to 12,594 nitrate-attributable cancer cases occur annually in the U.S., of which 54-82% are colorectal cancer .This costs $1.5 to $6.5 billion dollars per year.

Water Research Australia has updated its “Good Practice Guide to the Operation of Drinking Water Supply Systems for the Management of Microbial Risk” which serves as an evaluation and benchmarking tool. The guide is only available to members of WaterRA.

Changing from chlorination to chloramination has been known to increase lead levels in drinking water systems. This can be avoided by beginning phosphate dosing prior to the change-over.

This book chapter describes the development, validation, and implementation of the human-associated HF183 Bacteroides quantitative real-time PCR technology for water quality and public health protection applications.

Fluorescent dissolved organic matter (DOM) is strongly correlated with E. coli. and total bacterial cell counts. It is a superior indicator than turbidity of microbial water quality.

Researchers at Harvard Medical School and the New York State Department of Health have discovered how a common plasticizer associated with human reproductive abnormalities likely does its damage at the molecular level. Various U.S. federal and state agencies responded by passing laws limiting the percentage of DEHP and other phthalates in children's toys, food packaging, drinking water and other items. DEHP has been banned in Europe since February 2015.

Researchers analyzed water governance regulations in six European countries from 1750 to 2006 and show that rules designed to improve resource management come into conflict in the long run, creating an equal number of positive and negative effects until the system falls apart.

Pilot plant studies demonstrated that ozone with biological filtration could achieve potable water quality criteria, without the use of RO, in cases where nitrate is below the MCL of 10 mg nitrogen per liter and total dissolved solids are below the SMCL of 500 mg per liter. Trials with a range of blending ratios showed that finished water from the direct reuse plant had no detections of microorganisms even at 100% . However, exceedances of one or more quality standards were observed at blends above 15%.

Using ¹³C labelled polyethylene, workers in Finland were able to demonstrate that aquatic micro-organisms can produce, biochemically upgrade, and trophically transfer nutritionally important biomolecules from PE-MP.

Workers in the USA have developed networks of artificial membranes which could prove useful for separating salt from water, a filtration process that is currently inefficient and costly. The new membrane has shown impressive desalination properties, exhibiting far more selective salt and presumably other contaminant removal when compared with existing processes. The method is a thousand times more efficient than current desalination processes in terms of its selectivity and permeability.

106 samples from 4 sources were collected in 5 European regions and 30 faecal indicators and source tracking markers were evaluated, including E. coli, enterococci, clostridia, bifidobacteria, somatic coliphages, host-specific bacteria, human viruses, host mitochondrial DNA, host-specific bacteriophages and artificial sweeteners. Models based on linear discriminant analysis (LDA) able to distinguish between human and non-human faecal pollution and identify faecal pollution of several origins were developed and tested with 36 additional laboratory-made samples. With 5 variables the model correctly classified all the fresh faecal samples from 4 different sources.

The magPOM‐SILP composite is composed of a superparamagnetic iron oxide (Fe₂O₃, hematite) core encased in a porous silica shell and is capable of removing organic, inorganic, microbial, and microplastic pollutants from water using a range of target‐specific removal modes. High removal efficiencies are reported.

WHO has released a publication which provides a rationale for decision-makers to promote and support uptake of risk-based approaches in regulations and surveillance practice. It has been designed around six key messages that underlie the concept of risk-based approaches in drinking-water surveillance and is supported by practical examples for illustration purposes.

Switch of source water in iron mains may induce “red water” episodes. This study investigated the impacts of water quality on iron release, dissolved oxygen consumption (ΔDO), corrosion scale evolution and bacterial community succession in cast iron pipes. The paper proposes a water switch strategy to minimse risk of discolouration.

A review of 70 peer-reviewed studies found that 80.2% ± 29.0 and 57.2% ± 36.8 of aggregated groundwater isolates were resistant to ≥1 and ≥3 antimicrobials, respectively. Where bacteria were present, antibiotic resistant bacteria (ARB) were identified in 76.9% ± 33.7 of individual wells and springs. The reviewers consider that their results leave little doubt that groundwater represents a major global reservoir for ARB.

Having developed high sensitivity simple methods for the analysis of trihalomethanes (THM4), iodinated-trihalomethanes (I-THMs), haloacetic acids (HAAs), bromide, iodide and iodate,these workers showed that in a full-scale treatment plant I-THMs were constantly formed independently of iodine concentration. They also showed that bromoacetic acid accounts for 60% of the relative toxicity of 17 DBPs.

An interesting Californian study has shown that consumers may accept the safety of, and need for, recycling of water, but are still reluctant to accept it because of “disgust” at the reality.