News Items Archive 2021

Studies at 27 drnking water treatment plants (DWTP) over 2 years showed no proportionalities between the log of mean E. coli concentrations and the log of mean protozoa concentrations. E. coli/protozoa ratios at DWTPs supplied by small rivers in agricultural and forested areas were typically 1.0 to 2.0-log lower than at DWTPs supplied by large rivers in urban areas. Therefore, an E. coli trigger level would have limited value for defining health-based treatment requirements for protozoa at DWTPs supplied by small rivers in rural area.

This US study looks at how physicochemical parameters, mainly monochloramine residual concentration, hydraulic residence time (HRT), and seasonality, affected the occurrence and concentrations of four common OPs (Legionella, Mycobacterium, Pseudomonas, and Vermamoeba vermiformis) in four full-scale DWDS in the US. Legionella positively correlated with Mycobacterium, Pseudomonas, and total bacteria. Multiple regression with data from the four drinking water distribution systems (DWDS) showed that Legionella had significant correlations with total chlorine residual level, free ammonia concentration, and trihalomethane concentration. The study demonstrates how the significant spatiotemporal variations of OP concentrations in chloraminated DWDS correlated with critical physicochemical water quality parameters such as disinfectant residual levels. This work also indicates that Legionella is a promising indicator of OPs and microbial water quality in chloraminated DWDSs.

This study carried out over 14 months in Uganda studied 40 groundwater sources and looked in depth at the statistical considerations. It concludes that Tryptophane-like fluorescence and Humic-like fluorescence provide a more repeatable and temporally robust approach than faecal indicator organisms to ranking sources by faecal contamination risk across a community in order to strategise prioritisation of sources for drinking or interventions.

US scientists and engineers have created a hydrogel tablet that can rapidly purify contaminated water. One tablet can disinfect a liter of river water and make it suitable for drinking in an hour or less. The special hydrogels generate hydrogen peroxide to neutralize bacteria at an efficiency rate of more than 99.999%. The hydrogen peroxide works with activated carbon particles to attack essential cell components of bacteria and disrupt their metabolism.

A process known as shock electrodialysis has been shonn at small scale to be effective at lead removal from water. With filtration systems, for example, the costs are mainly for replacing the filter materials, which quickly clog up and become unusable, whereas in this system the costs are mostly for the ongoing energy input, which is very small. So far it has has only been demonstrated at small laboratory scale and at quite slow flow rates.

ATP is often monitored as an index of biological acclimation of biological filters but strong correlations between ATP concentration and filter performance (e.g., organic matter or disinfection by-product precursor removal) are not typically observed. This study evaluated the use of enzyme activity for monitoring biological processes within filters and showed that enzyme activity may be appropriate for monitoring biological processes within drinking water filters and may act as a surrogate for the removal of organic compounds.

This Swedish study based on national data over 10 years found TTHM exposure was associated with increased risk of malformations of the nervous system, urinary system, genitals, and limbs in areas exclusively using chloramine. No associations were observed in areas using exclusively hypochlorite as the primary water treatment method An association between chloramine-related chlorination by-products and congenital malformations has not previously been highlighted

Chlorination of PAC can form DBPs, including THMs and HAAs. More toxic products were formed when using PAC and chlorine at the same time.

Water Research Austraalia has issued a factsheet on this compound, which can be produced by cyanobacteria. This compound has been postulated as implicated in a neurodegenertive condition. The absence of reliable detection methods has led to many conflicting research studies, and has complicated efforts to compare findings across different studies despite the resources and intellectual efforts devoted to this topic, the effects of BMAA on public health continue to be heavily debated.

This study of 12 distribution systems known to be prone to discolouutation events found that although loose deposits could be visualized during water discoloration, toxicity risks could not be evaluated through aesthetic indicators although particle size showed a stronger correlation with toxicity than other properties.

This Chinese review provides a comprehensive overview of the occurrence, detection, and control of odor substances derived from drinking water chlor(am)ination disinfection.

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a useful tool for identtification of bacterial isolates but hitherto has been mostly used in a clinical environment. These workers have developed a database of 319 species which might be encountered in water intended for human consumption.

These workers, having studied microbial communities in ccontact with a range of pipe materials, concluded that pipe material is an important factor that influences the biomass concentration, abundance of specific microorganisms and the bacterial community composition in distribution systems with unchlorinated drinking water.

Focussing on personal water-use activities rather than measured household consumption these workers concluded that a minimum target of 79 l/d/caapita during stringent water restrictions was appropriate. A more realistic expected value for non-wasteful, indoor-only water use was determined to be 175 l/d/capita/day.

This Swedish study found that effluents from a Swedish hospital strongly select for multi-resistant E. coli. whereas municipal effluents showed no such selection.

This review considers detection of, and formation pathways for, chlor(am)ination odours, and methods for their removal.

This expert review concludes that complete removal of lead components is the only way to achieve close to zero lead; and regulation, funding and public awareness are required to stimulate positive action on lead.

This excellent and comprehensive publication by Water Research Australia is available free of charge to staff of WaterRA member organisations and by annual paid subscription to other readers with an interest in water quality issues. Issue102 published July 2021 has abstracts from a wide range of recent papers and includes a summary of 23 reported waterborne disease outbreaks over the past 10 years in advanced economies.

This study of water supply in Barcelona shows that if the whole population of Barcelona decided to shift to bottled water, the production required would take a toll of 1.43 species lost per year and cost of 83.9 million USD per year due to extraction of raw materials. This is approximately 1,400 times more impact in ecosystems and 3,500 times higher cost of resource extraction compared to the scenario where the whole population would shift to tap water. However this would increase the overall number of years of life lost in the city of Barcelona to 309 (which equals approximately on average 2 hours of lost life expectancy if borne equally by all residents of Barcelona). Adding domestic filtration to tap water would reduce that risk considerably , lowering the total number of years of life lost to 36.

US workers incorporated fluorine into an amino acid and mixed it with a fluorinated oil. When added to water in a vial it formed a bead comprised of the fluorine droplet surrounded by an amino acid coating When inverting the vial to expose the bead to air, the bead's components rearranged to form a film The film captured PFAS substances within two hours and was able to hold them for up to 24 hours. From this stage, the film containing PFAS could be agitated to reform itself into a cohesive bead that could be easily collected from the now-purified water. This material could be implemented to remove PFAS from drinking water.

This study compared six commercially available microbiological devices set up in a full-scale drinking water production plant. In order of sensitivity, enzymatic analysis, ATP measurement, and flow cytometric fingerprinting were the most performant for detection of rain- and groundwater contaminations (0.01 – 0.1 v%). On the other hand, optical classification and flow cytometric cell counts were shown to be more robust techniques. All techniques were more sensitive then plate counting.

Workers at Cardiff University have shown that the reactive oxygen species—which include hydroxyl, hydroperoxyl and superoxide radicals—formed over a AuPd catalyst during the synthesis of hydrogen peroxide from hydrogen and air are over 107 times more potent than an equivalent amount of preformed hydrogen peroxide and over 108 times more effective than chlorination under equivalent conditions when teted against E.coli.

Water Research Australia has produced a Factsheet addressing the potential use of electrical splitting of water to produce hydrogen peroxide and hydrogen from recycled wastewater for water purification. The identification of key impurities in recycled wastewater and an assessment on their impacts on electrochemical processes are necessary to assess the feasibility of utilising recycled water for electrochemical water splitting.

Pipe loop studies showed that after 6 hour interrupted supply the risk of formation of disinfection byproducts was greater than after 48 or 144 hour interruptions while the longer interruptions led to higher risk of discolouration and changes in biofilm and planktonic populations. Long IWS times favour the risk associated of potential pathogenic microorganisms.

Ofwat, DEFRA, the Environment Agency, DWI and the Consumer Council for Water have set out their ambition to build back greener from the pandemic: delivering lasting environmental improvements for current and future generations, while meeting the economic and social challenges England faces. Formal proposals to enhance the environment and public health have been submitted from five companies: Severn Trent Water, South Staffs Water, South West Water, Thames Water, and United Utilities. Ofwat has published draft decisions on arrangements for providing fundingto companies, cost sharing rates, scheme delivery and reporting requirements,

This review provides a comprehensive overview of the recent advances in the emerging microplastics removal and transformation technologies. The authors believe the review will guide researchers to further explore the feasible approaches and develop new strategies for advanced control and remediation of microplastics.

Researchers have created a molecule-sized water transport channel that can carry water between cells while excluding protons and undesired molecules. These channels mimic the water transport functions of proteins in our bodies known as aquaporins. They could improve the ability of membranes to efficiently filter out unwanted molecules and elements, while speeding up water transport, making it cheaper to create a clean supply.

Studies during the progressive change from intermittent to continuous water supply in Nagpur, India showed that intermittent water supply was associated with fecal contamination as detected by cultural and molecular methods. Despite the presence of piped on premise infrastructure, intermittent water supply is less likely to meet the requirements for safely-managed drinking water.

The results of this study suggest that nitrate in drinking water is associated with increased odds of spontaneous preterm birth. Notably, it estimated modestly increased odds associated with tap water nitrate concentrations of 5 to <10mg/L as nitrogen (below the federal drinking water standard of 10mg/L) relative to <5mg/L.

Swiss researchers are developing a new filter membrane that is highly efficient at filtering and inactivating a wide variety of air-borne and water-borne viruses. The membrane eliminates a wide range of water-borne viruses, including nonenveloped adenoviruses, retroviruses and enteroviruses as well as H1N1 flu viruses and even the new SARS-CoV-2 virus .

Workers in Germany have developed a new chemical process for removing hormones from water. It takes advantage of the mechanisms of photocatalysis and transforms the pollutants into potentially safe oxidation products. It is not at the stage where it can be used in full scale water treatment.

Researchers have created a molecule-sized water transport channel that can carry water between cells while excluding protons and undesired molecules. These channels mimic the water transport functions of proteins in our bodies known as aquaporins. They could improve the ability of membranes to efficiently filter out unwanted molecules and elements, while speeding up water transport, making it cheaper to create a clean supply.

39 of 101 products tested were positive for PFAS with purified water containing less than spring water. Although no enforceable PFAS regulations exist for bottled water in the U.S., the finding that some products approach levels of concern justifies a framework for monitoring PFAS in bottled water production.

This paper shows that in karst regions, which are characterized by an increased occurrence of cracks or fissures, the risk of pollution by degradable pollutants such as pesticides, pharmaceuticals or pathogens is significantly higher than previously expected. Although pollutants are considered short-lived, up to 50 percent of them can still reach groundwater, depending on the period of their decomposition.

This Swedish study population consisted solely of middle-aged to elderly women in Sweden, and thus its findings may not apply to other population subgroups or to women in other countries. However it suggest that long-term consumption of tap water with a fluoride concentration of 1mg/L, which is below the 1.5mg/L maximum concentration recommended by the WHO, may adversely affect bone health in postmenopausal women.

This study carried out in rural China showed that boiling water in open pots is less effective than in lidded kettles. Bottled water was found to frequently have high levels of total coliforms despite which a relatively high proportion of rural households tused bottled water as their primary source of drinking water.

This laboratory study looks at the effect of ozone, chlorine and u-v on bacterial cells and antibiotic resistance genes (ARG) in water. While the impact of ozone was similar on bacterial cells and ARG, for chlorine and UV, inactivation of bacterial cells was observed at lower doses than those needed for the decrease of ARG copy numbers. Although UV and chlorine treatments were effective in the inactivation of bacterial cells, incomplete degradation of ARGs was observed. Therefore, plasmid-borne ARGs can potentially be transferred to other bacteria even after the disinfection.

Laboratory studies using fathead minows showed that metformin acts as an endocrine disruptor at environmentally relevant concentrations.

This very comprehensive paper concludes that based on predicted environmental concentrations and predicted no effect concentrations there is no risk to aquatic life from metformin nor its metabolite guanylurea.

This paper describes the development of robust, selective, and tunable adsorptive membranes that feature porous aromatic framework nanoparticles embedded within ion exchange polymers and demonstrate their use in an efficient, one-step separation strategy.

A recombinase polymerase amplification (RPA) can amplify and detect E. coli DNA in fewer than 3 min. Although the RPA method was less sensitive than qPCR, it was significantly more rapid. The speed, selectivity and isothermal low temperature requirements of the RPA technique make it well‐suited for on‐site water quality testing. The current LOD for the method would limit its application to relatively high‐level contamination events, for example sewerage overflows/leaks. The authors suggest considering using mRNA primers to negate the impact of dead cells. ( this is very much “work in progress” but offers potential)

A Spanish survey was carried out on c.1750 samples from cooling towers and evaporative condensers (CTC), and water distribution networks such as domestic hot water (DHW), cold water for human consumption (CW), sprinkler irrigation systems (SIS), fire sprinkler systems (FSS), and water from decorative fountains (DF). Legionellae were found in 15.79% of all samples and Legionella non-pneumophila was isolated from 13 of the 18 locations sampled with Legionella pneumophila being isolated with similar frequency .High colonization was more frequently detected.

WHO has published an updated 2nd edition of its 1999 Guide which presents the current state of knowledge on the occurrence of cyanobacteria and cyanotoxins, as well as their impacts on health through water-related exposure pathways, chiefly drinking-water and recreational activity.

The US CDC has published a toolkit describing best practices in preparing for, identifying, and remediating a waterborne disease outbreak.

This paper reviewed 50 published sudies on microplastics in lake water, groundwater, tap water and bottled drinking water. Only four of the studies received positive scores for all proposed quality criteria, implying there is a significant need to improve quality assurance of microplastic sampling and analysis in water samples.

A Danish study of 898,206 births over 20 years showed a small reduction in birth weight and body length associated with maternal nitrate consumption but little evidence for an association between nitrate and head circumference or low birth weight.. The paper includes several caveats.

Pilot scale studies showed that orthophosphate dosing with pH aadjustment was more effective than sodium silicate in reducing lead release from pipes although silicate resulted in lower levels of biofilm accumulation on pipe walls.

Workers in the Netherlands have shown that unchlorinated PVC is the preferred material to control microbial growth in drinking water systems while fungi are dominant in water and V. vermiformis is dominant in biofilm.

This study shows that transient presure events mobilise deposits in mains and mobilisation always occurs in the first dynamic surge of the transient.

Workers in China have shown significant quantities of viable/VBNC opportunistic pathogens in full-scale DWTPs, confirming that traditional, culture-dependent methods are inadequate for detecting VBNC bacteria.

Metformin usage is growing and is likely to continue. It is not metabolised by humans and therefore is found in wastewater worldwide.This paper concludes that the current doses of MET present in drinking water are not of direct safety concern to humans, however the potential threats of its chlorination byproducts should not be ignored.

This Danish study concludes that Mn in drinking water was associated with ADHD, specifically the ADHD-Inattentive subtype. Its results support earlier studies suggesting a need for a formal health-based drinking water guideline value for Mn.

This review discusses Cryptosporidium and methods available for their detection including microscopy, immunology, nucleic acid-based methods and DNA aptamers. Aptamer-based detection is developing and has higher sensitivity and specificity as well as performing better in environmental samples with PCR inhibitors.

This study was conducted to investigate the occurrence of ARGs in full-scale BAC filters during the backwash cycle using high-throughput qPCR and high-throughput sequencing. After backwashing, the relative ARGs abundance increased by 1.5- to 3.8-folds and the absolute ARGs abundance increased by 0.90- to 1.12-logs in all biofilm samples during filter ripening, indicating that ARGs accumulated in filters during this period. The authors consider that given the high richness and relative abundance of ARGs in BAC filter and the ineffectiveness of backwashing in ARG removal, more stringent downstream disinfection strategies are deserved and more research is necessary to assess potential human health risks due to the persistence of ARGs in drinking water.

On 16 December 2020 the European Parliament formally adopted a revised Drinking Water Directive which came into force on January 12th 2021.After Brexit the UK is not obliged to adopt the new Directive but it is anticipated to have regard to it in future regulation.

This critical review introduces the application of a novel approach called Reactivity-Directed Analysis (RDA) to assess and identify organic electrophiles, the largest group of known environmental toxicants. In contrast to existing in vivo and in vitro approaches, RDA utilizes in chemico methodologies that investigate the re action of organic electrophiles with nucleophilic biomolecules, including proteins and DNA This summary is followed by an overview of existing RDA approaches and their application for the assessment of aqueous environmental matrices, with an emphasis on drinking water.

18 US states entered 421 reports on the One Health Harmful Algal Bloom System during 2016–2018, including information about 389 human illnesses and at least 413 animal illnesses associated with harmful algal bloom events. The report recognises a number of limitations in its content but further developments can be anticipated.

This very comprehensive study by no less than 21 authors looks at data from 2000 to 2015 and shows that domestic waterborne transmission of 17 diseases in the United States caused ≈7.15 million (95% CrI 3.88–12.0 million) waterborne illnesses to occur annually during the study period, including 601,000 ED visits (95% CrI 364,000–866,000), 118,000 hospitalizations (95% CrI 86,800–150,000), and 6,630 deaths (95% CrI 4,520–8,870), and incurred $3.33 billion (95% CrI $1.31–$8.71 billion) in hospitalization and ED visit costs. This estimate includes drinking, recreational, and environmental water exposures. The report however contains many caveats and its findings shouldbe viewed with caution.

This paper suggests that as a corrosion control treatment for lead, sodium silicate is inferior to orthophosphate in circumneutral pH water with low alkalinity. and, as with polyphosphate, excess silicate can be highly detrimental to controlling lead release.

This thesis describes the application of in situ fluorometers for monitoring algal blooms in water supply systems, giving results in minutes facilitating the timely adjustement of PAC and coagulant dosing.