News Items

Flushing of household plumbing systems. (Posted 15/04/2019)
This paper looked at best practice for post-incident flushing of water supply plumbing in single premises. After considering existing guidance and the reading level required of recipients it produces guidance which recommends progressively opening all cold-water taps from the closest to point of entry to the furthest and allowing the water to run for at least 20 minutes while hot-water taps should be opened progressively and run for at least 75 minutes.

Microplastics in raw and treated drinking water (Posted 15/04/2019)
Another paper on this very topical topic. Czech Republic workers studied 3 water treatment works and found microplastics (MP) in all samples of raw and treated water at 3 works. Up to 95% of MP were in the range 1-10μm and the treated waters contained from 338 to 628 particles/litre.

Microplastics in drinking water from groundwater sources. (Posted 15/04/2019)
This study looked for microplastics >20μm and found <1 particle/m3. Clearly agreement is required on what constitutes microplastics and perhaps a size range classification.

Making lead pipes safe (Posted 10/04/2019)
Scientists have described a rapid, cost-effective method to overcome problems when changes in water source or treatment have led to loss of scale. They propose that lead pipes can be made safe by application of an external low-voltage electrical charge to speed up scale formation with phosphate.

How to distinguish urban vs. agricultural sources of persistent organic pollutants (Posted 10/04/2019)
This paper presents a relatively simple and effective method for distinguishing between urban and agricultural sources of anthropogenic chemicals. Application at a number of sites showed some classes of materials, including PCBs, to be mainly urban in origin while others, such as hexachlorocyclohexanes were mainly derived from agriculture. Surprisingly DDT had a strong urban signature.

Microplastics in freshwaters and drinking water. (Posted 09/04/2019)
WHO has commisioned this review of microplastics in freshwaters and drinking water which is intended to inform a report to be published on potential risks to public health from microplastics in drinking water. It proposes best practices for microplastic occurrence studies.

Microplastics in drinking water. (Posted 28/03/2019)
An excellent review of current knowledge about microplastics (MP) in drinking water with a bibliography of 52 papers. The review shows that MP can be found in both surface water and groundwater sources and in treated drinking water.

Disinfectant residual stability. (Posted 28/03/2019)
A recent review aims to give an understanding of how disinfectant residual stability in drinking water distribution systems is impacted by various influencing factors such as water quality and operational parameters. Important factors wea identified to include temperature, water age, piping material, corrosion products, pH, hydraulic condition, disinfectant residual type and dosage and microbial activity. Of 1809 relevant papers identified since 1998, 161 were assessed in detail.

Sachet water in Africa (Posted 28/03/2019)
In many African countries continuous fully-treated drinking supplies are not available and many people purchae driniking water in sachets which is widely believed to be “pure and safe” A study of 5 commercially marketed sachet supplies used by students in Ghana showed none to meet WHO Guidelines for coliforms or faecal coliforms, all having faecal coliform counts in excess of 105/100ml.

Antibiotic resistance in drinking water systems (Posted 27/03/2019)
A recent review has critically examined the occurrence of antibiotic resistance in groundwater, surface water, and treated distributed water. It concludes that combining UV-irradiation with advanced oxidative processes (such as UV/chlorine, UV/H2O2, and H2O2/UV/TiO2) may enhance the removal of antibiotic resistant bacteria and genes, while disinfection may promote horizontal gene transfer from environmental antibiotic resistant bacteria to pathogens.

True exposure to lead at the tap (Posted 27/03/2019)
A study in Canada on lead exposure in tapwater in 29 households used proportional sampling as the gold standard to which the other protocols, 5-min flush, 30-min stagnation, 6-h stagnation and random daytime were compared. Random daytime samples provided mean lead levels closest to true exposure in the households monitored overall compared to other sampling protocols. Strikingly, mean lead levels after 5 min of flushing underestimated lead exposure by 47%.

Review of microplastics in fresh and drinking water. (Posted 14/03/2019)
A review of 50 papers on microplastics in fresh and drinking water concludes that only 4 of these met all the criteria the authors proposed for the quality of studies. They conclude that more high quality data is needed on the occurrence of microplastics in drinking water, to better understand potential exposure and to inform human health risk assessments.

Ingested nitrate, disinfection by-products, and risk of colon and rectal cancers in women.(Posted 14/03/2019)
A recent study from the Czech Republic suggests that exposure to TTHM in drinking water is associated with increased risk of rectal cancer. Positive findings for individual THMs and Haloacetic acids (HAAs) for both colon and rectal cancers require replication in other studies. We found no associations for nitrate overall or in subgroups with presumed higher NOC exposure.

Detection of drugs of abuse in drinking water. (Posted (11/03/2019)
Workers at Anglia Ruskin University in Cambridge UK using LC-MS examined tap water for 20 drugs of abuse and pharmaceuticals and detected 5 drugs of abuse and 2 pharmaceuticals including mephedone and methylone which have not been reported in drinking water before. Detections were in the range of 0.14 to 2.81 ng/L.

1-4dioxane in drinking water. (Posted 19/02/2019)
Workers in the USA have published a review of 1,4dioxane in drinking water highlighting recent advances in analytical methods, understanding of occurrence, and treatment processes. Although the WHO Guideline value in drinking water is 50 μg/l the authors cite a “health-based reference concentration of 0.35 μg/L” and suggest “a need for developing and implementing management and treatment approaches that protect drinking water sources and prevent human exposure to 1,4-dioxane through drinking water.”

Phthalates effect on female reproduction in mice (Posted 19/02/2019)
Feeding female mice environmentally relevant concentrations of Di(2-ethylhexyl) phthalate (DEHP) or Diisononyl phthalate (DiNP) ranging from 20 micrograms to 200 milligrams per kilogram of body weight showed that DEHP and DiNP exposure has long-term consequences for female reproduction in mice, even long after cessation of exposure. ( WHO Guidelines note that primates are less susceptible than rodents to oral exposure to DEHP but set a Guideline value of 8μg/l for DEHP in drinking water).

Highly Efficient Metal-free Photocatalyst for Safe Drinking Water (Posted 19/02/2019
Workers in China have developed edge-functionalized graphitic carbon nitride (g-C3N4) as a photocatalytic disinfectant. They show that the pathogen-rich water can be rapidly purified in 30 min with a disinfection efficiency of over 99.9999% under visible-light irradiation,

New method to simultaneously quantify priority disinfection by-products (Posted 10/02/2019)
A new gas chromatography (GC)-mass spectrometry (MS) method iis described that simultaneously quantifies 39 priority unregulated DBPs from six different chemical classes (haloacetaldehydes, haloketones, haloacetamides, haloacetonitriles, halonitromethanes, and iodinated-trihalomethanes) and analyzes unknown DBPs with mass accuracy<600 ppm under full-scan conditions.

Novel method for enumeration of coliphages (Posted 10/02/2019)
Workers based in Australia have developed the QuantiPhage method which uses a cellulose pad instead of the agar used in the conventional double layer overlay. This enables coliphages to be detected in water in under 3 hours.

Reducing PFAS in Drinking Water with Treatment Technologies (Posted 10/02/2019)
USEPA has produced a useful review of the ability of water treatment technologies to remove per- and poly-fluorinated substances (PFAs) from water.

Flow cytometry applications in water treatment, distribution, and reuse (Posted 10/02/2019)
Two Californian workers have published a useful review of almost 300 published papers on applications of Flow Cytometry to water. They suggest that more work is needed to realize the full potential of FCM in water treatment, distribution, annd reuse. Nonetheless they suggest that there is now a sufficiently large body of research documenting successful applications of FCM that the approach could reasonably and realistically see widespread adoption as a routine method for water quality assessment.

Bacteria-derived filter inactivates bacteria. (Posted 28/01/2019)
Workers in the USA produced membranes from bacterial cellulose using Gluconacetobacter hansenii bacteria and incorporating reduced graphene oxide (GO). In sunlight the membranes rapidly heated up to inactivate E.coli within 3 minutes whereas similar membranes without the reduced GO did not inactivate E.coli.

Persistent and mobile organic chemicals (PMOC) in water (Posted 28/01/2019)
A group of German annd Spanish workers, using a prioritized list of industrial chemicals that were modeled to be persistent, mobile, and emitted into the environment, successfully developed methods for 57 target PMOCs. Applying these to 14 water samples from three European countries a total of 43 PMOCs were detected in at least one sample, among them 23 PMOCs that have not been reported before to occur in environmental waters. ( There are at present no reasons to believe these compounds are of any significance in water supplies).

Review of non-tuberculous Mycobacteria in water (Posted 22/01/2019)
Epidemiological studies suggest that natural and drinking water are principal sources of infection with these organisms. This review looks at the factors favoring the presence of these bacteria in natural and artificial water systems, and the effectiveness of water treatment.

Analysis of disinfection by-products (DBP) (Posted 22/01/2019)
This review discusses current analytical methods and challenges associated with the identification and measurement of DBPs mainly published in the last two years.

Robots to fix underground pipes (Posted 22/01/2019)
As part of a £26.6 million Government backed Investment Scheme, scientists from four British universities will use £7 million government investment to develop 1cm-long robotic devices that use sensors and navigation systems to find and mend cracks in pipes.

Antibiotic resistance genes (ARG) in tap water. (Posted 22/01/2019)
Chinese workers have studied antibiotic resistance genes in small bacteria in tap waters. 265 ARG subtypes belonging to 17 ARG types were detected at abundances ranging from 4.0 × 10−2 to 1.0 × 100 copies/cell. Multidrug, bacitracin and aminoglycoside resistance genes were dominant, and 43 ARG subtypes were specifically carried by small-size microbes.

A review of Flow cytometry applications in water treatment, distribution, and reuse. (Posted 10/01/2019)
After reviewing almost 300 recent papers the authors conclude that while more work is needed to realize the full potential of Flow Cytometry in water treatment, distribution, and reuse, substantial progress has been made over the past two decades. There is now a sufficiently large body of research documenting successful applications of FCM that the approach could reasonably and realistically see widespread adoption as a routine method for water quality assessment.

Informing public attitudes to use of recycled water (Posted 10/01/19)
A recent study in London evaluated how different ways of framing messages about the safety of non-potable use of recycled water might impact on public attitudes. The study found a positive impact of water safety communications framed in terms of compliance with water quality requirements. Contrarily, a positive attitudinal impact was not evident for safety message framed in terms of the selection of water treatment technology to remove contaminants nor in terms of non-potable water risks relative to other every-day risks.

Rapid field quantification of Escherichia coli in surface waters (Posted 10/01/2019)
Workers in France have evaluated the ALERT automated monitoring system, which uses defined substrates to measure ß glucuronidase ( indicative of E coli) and ß galactosidase ( indicative of coliforms) activity in surface waters by comparison with conventional most probable number (MPN) methods using natural river waters. They conclude that ALERT technology is an accurate and rapid bacterial quantification technology, capable of autonomous in situ measurements with metrological capabilities comparable to those of an approved laboratory using MPN microplate techniques.

Impact of blending for direct potable reuse on premise plumbing microbial ecology. (Posted 10/01/2019)
Bench and pilot scale studies on the impact of introducing treated recycled water into distribution system were carried out by US workers. Measurement of regrowth of total bacteria, opportunist pathogens, and antibiotic resistance genes showed almost no effect from the introduction of recycled water.

Waste Management when supplying bottled water (Posted 10/01/2019)
When bottled water was supplied in Flint, Michigan to c97,000 people, starting in October 2015 it is estimated that some 80 million disposable plastic bottles were used in the first 6 months. At the outset no contingency plans were in place to handle the waste plastic and there is little hard data to firm up estimates.. In addition some households were given point of use filters which meant used cartridges also needed disposal. Alarmingly 8% of households remained unaware that there was a problem with lead in their water supply as information was only supplied in English even to non-English speaking households. (This paper should be essential reading for water suppliers who can learn from the many deficiencies in the handling of this incident and ensure they have adequate plans for major water supply emergencies.)