Community Water Lab!

In collaboration with ZERO Guildford and the River Wey Trust, we launched the Water Rangers Community Water Lab on April 27th, 2024.

What is it?

We’ve building a lab space that provides an affordable way for communities to get answers about water quality. We continue to monitor for water chemistry monthly, but this lab will extend that! Our first focus is on providing testing capability for E. coli monitoring.

This lab is available to be used by all: people across the region are welcome to use this resource.

We’re using the IDEXX Colilert Most Probably Number (MPN) method, which has been used for more than 20 years for beach monitoring in other places (e.g. Swim Drink Fish Canada has been an inspiration!). It’s also an ISO certified method, meaning we can trust our results.

Why do we need it?

Right now, there are no simple ways for the public to get information on E. coli monitoring, the main test used to understand human health risks in recreational water. It means that we don’t know if wild swimmers or boaters are at higher risk (recommended levels are that E. coli readings don’t exceed 1000 CFU/100mL, but there will always be risk in natural waterways). Our goal is to begin to understand where areas regularly exceed guidelines for human health and work with partners in the Wey Landscape Partnership and others to solve problems.

How does it work?

Members of the public can buy a test for £15 each at ZERO that will give you results for both Total Coliforms and E. coli. For recreational water quality, taking three samples at a time to ensure accuracy. For understanding trends, you may only take one sample at a time. We’re getting started this way! You’ll need to sample 16 times in a single spot to get a true baseline picture of results.

• Earlier in the week: Come to ZERO Guildford to pick up a ‘collection kit’ that walks you through how to collect your sample. ZERO is open Tuesday – Saturday from 10am – 4pm. Ask at the café for access to the sign-out cupboard
• Friday morning: Collect your sample early Friday morning (following the instructions) and then bring it into ZERO Guildford between 10 a.m. and 11 a.m. Our volunteers process the samples and incubate them overnight.
• Saturday morning: Volunteers read the results between 10:30 a.m. and 12:30 p.m. Results are posted on our results page, sent to the data collector (and published on the open data platform). You get a reading for E. coli and Total Coliforms.
• If it’s a sponsored spot, the results will be available on the local sign right next to the waterbody so that members of the public can access the latest results right there.

How can I get involved?

We’re looking for volunteers to help us collect water samples Friday morning, process samples Friday morning, and read the results on Saturday morning. Sign up to volunteer through ZERO’s volunteer program. We need three-four volunteers each day.

Godalming Town Council has provided funding for one initial sample at various locations, but this does not allow us to test every week. Therefore, we are seeking funding to sponsor regular monitoring at popular recreation spots. If you have any leads on funding, that is our biggest barrier to taking on the cost of doing that testing ourselves. If funding is secured, we’ll need volunteers to collect samples weekly!