Water Testing

Since May 2023 we have been working with the Westcountry Rivers Trust (WRT) testing the water of the River Isle. We now have (albeit patchy) coverage from the Isle’s source in Combe St Nicholas to the confluence with the River Parrett at Muchelney. Our citizen scientist volunteers go through an online training programme with the WRT before being signed up and sent the testing equipment that allows them to measure:

· Phosphates

· Total Dissolved Solids

· Turbidity

· Temperature

-at their testing site. The sites are suggested by WRT, but are down to the individual to choose, dependent on where they live, accessibility, etc. Most of our test sites are on the section between Combe St Nicholas and Ilminster. North of Ilminster we are a bit thin on the ground and need more volunteers. This stretch is currently covered by a quarterly hit squad covering six sites in one day. Most volunteers cover just one or two sites and sample them on a monthly basis.

As well as the quantitative measurements above the monthly survey also involves qualitative observations on visible signs of pollution, weather, invasive plant species, wildlife seen, etc.

The results of each survey are input by the volunteers into a database called Cartographer and used by WRT to provide organizations like the Environment Agency with granular data to help make important decisions about the health of the river and remedial actions that need to be taken.

Currently WRT rate the River Isle to be in ‘Fair’ to ‘Good’ condition*, but phosphate levels are letting it down. These can only be coming from two sources – farming run-off and sewage treatment plants. Monitoring on a monthly basis is crucial to make sure that any serious incidents are spotted before too much damage is done and with a view to collecting enough data that pressure can be brought to bear on the sources of pollution so it can be reduced. We still have kingfishers and otters on the River Isle and long may that remain the case. We must remain vigilant and if you would like to add to our numbers you would be very welcome. To join us, email volunteer@greenilminster.org.uk.