The South East Rivers Trust (SERT) recently completed a chemical pollution survey across three local rivers to understand what harmful substances are polluting our waterways. The project, funded by the Environment Agency (EA) and carried out in partnership with Imperial College London, used special devices called passive chemical samplers to detect various chemicals in the water.
Where did we test?
We focused on three tributaries in our river catchments:
- River Blackwater in the River Loddon Catchment
- Stanford Brook in the River Mole Catchment
- North Wey in the River Wey Catchment
At each tributary, we placed the sampling devices at five different locations along its course. The devices were positioned to capture data from both urban and rural areas. These devices stayed in the water for two weeks before being retrieved and sent to a lab for analysis.
What did we find?
We tested for the presence of 35 different chemicals, including antibiotics, prescription medications, recreational drugs, pesticides, and herbicides. Shockingly, we found about 62% of the 35 chemicals we tested for in all three rivers. Some of the most concerning chemicals detected include:
- Clarithromycin (an antibiotic)
- Imidacloprid (a neonicotinoid pesticide)
- Fipronil (used in flea and tick treatments)
Why does this matter?
The presence of these chemicals in our rivers is a serious issue. Antibiotics in the water can lead to the spread of antibiotic-resistant bacteria, which is a growing public health concern. Pesticides like neonicotinoids are particularly harmful to aquatic invertebrates such as dragonflies, snails and shrimps, which are crucial to the health of the entire river ecosystem.
What can be done?
To tackle this pollution, we need upgraded sewage treatment systems and improved agricultural land management practices. However, there are also nature-based solutions that can help, such as creating new wetlands. The South East Rivers Trust recently delivered a nature-based solution with the Chamber Mead wetland project. This project cleans 250 million litres of water through natural systems, effectively combating pollution. Wetlands play a crucial role in keeping our water clean by filtering out sediments, chemicals, and other pollutants. They also help remove excess nutrients that often come from farms and construction sites, locking up pollutants in their sediments, soils and vegetation.
How you can help
Protecting our rivers requires everyone’s effort. By supporting initiatives like our Chamber Mead wetlands, volunteering at local events and donating to help fund vital restoration projects, we can all contribute to cleaner, healthier rivers. Find out more about how you can help your local river: https://www.southeastriverstrust.org/take-action/