This week we have been out and about with South West Water deploying ChemcatchersTM passive samplers across our catchments as part of our Upstream Thinking project. We have developed this exciting new technology in conjunction with SWW, the University of Portsmouth and Natural Resources Wales. However this is the first time we have used them simultaneously across all our catchments.

These innovative ChemcatchersTM are designed to sit in the riverbed for a set period of time and ‘adsorb’ herbicides and pharmaceuticals from the river to assess concentrations within the water. This provides a more accurate assessment of the pesticide concentration within the river in comparison to more traditional methods such as spot sampling.

High concentrations of acid herbicides not only have a detrimental effect on the ecology of the river, they are also expensive for South West Water to remove at the Water Treatment Works. Detecting these chemicals and understanding where they have come from in the catchment helps us to work with land managers and effectively target on-the-ground advice and interventions.

Placed at strategic points within the catchments, the Chemcatchers™ are capable of detecting numerous acid-herbicides that originate from diffuse agricultural pollution, as well as metaldehyde (used to control slugs) and some common pharmaceuticals, which enter the system via domestic waste outlets. These Chemcatchers™ will remain in the river for six weeks and will detect any incidences that occur within that period. This will happen twice a year for the duration of the Upstream Thinking project.

To find out more about the science behind Chemcatchers™ view the video below.