Dr Wendy Williamson, Dr Brent Gilpin and Dr Chris Nokes are senior scientists with the Water Management Group at Environmental Science and Research (ESR). Their role is in understanding water quality where it affects people. This includes research into the adverse impacts on the quality of drinking water, recreational water and wastewater, and the measures taken to manage them.

Dr Wendy Williamson

Wendy is a microbial ecologist who is conducting research into the detection and identification of viruses in our drinking and recreational water.

Because viruses may be present in water in very low numbers, they are very hard to detect so are not routinely tested for at present. Unlike bacteria, many of which can be detected by growing in laboratory conditions, viruses will not grow outside a host body.

Wendy is working on ways to improve the methods for virus detection and to be able to identify which viruses are present. Her goal is to be able to develop a picture of the viral load present in our waterways and whether these viruses represent a risk to human health. In addition to virus studies, Wendy’s work includes understanding the presence of cyanobacteria and the impacts of their toxins on the health of people and animals through water consumption or contact.

Dr Brent Gilpin

Brent is a water molecular biologist who is developing ways to identify the source of faecal matter in water.

Traces of faecal matter are occasionally detected in our drinking water, and identifying the source of that pollution is important to ensure appropriate management steps are taken. For example, if the source of faecal pollution is actually from ducks or other wildfowl, replacing sewerage pipes or upgrading sewage treatment systems is unlikely to improve local water quality.

Brent hopes to develop a system by which it is possible to identify the source of contamination by looking at specific bacteria present in the sample. Birds, mammals and humans carry different bacteria as part of their digestive system, so the presence of Rhodococcus coprophilus indicates a herbivore source and Bifidobacterium adolescentis indicates a human origin for the faecal pollution.

Brent is using chemical indicators, such as fluorescent whitening agents, which show that the sample may be from humans. Brent is also developing rapid molecular assays for strain typing Campylobacter – a bacterium that is one of the main causes of foodborne disease in many countries.

Dr Chris Nokes

Chris is a water chemistry scientist presently researching how microorganisms, such as bacteria and viruses, survive in sediments.

Rain increases the amount of sediment and microorganisms carried by rivers. Under these conditions, the treatment of river water to produce safe drinking water is the most difficult. Chris hopes to be able to determine how risks to the safety of water supplies during rain can be reduced by understanding the factors affecting the number of microorganisms living in the sediment. He is also investigating the impact septic tanks have on ground water quality.

The Water Management Group at ESR have been involved in establishing PulseNet Aotearoa New Zealand, which joins the PulseNet networks in other countries. PulseNet is a real-time monitoring system using pulsed field gel electrophoresis to fingerprint strains of bacteria. This enables rapid identification, tracing and prevention of food and waterborne disease outbreaks. ESR’s work in establishing PulseNet Aotearoa New Zealand was recently recognised by the US Centers for Disease Control (CDC) with an International Recognition Award.

Useful links

Information about Pulsenet.

    Published 19 June 2008, Updated 10 February 2015