New Survey Finds Cocktail of Harmful Chemicals in Rivers Across the South East

Author: Sara Marshall

New Survey Finds Cocktail of Harmful Chemicals in Rivers Across the South East

Posted on by Sara Marshall

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:

Close-up of a plastic cap secured to a thin pole with a cable tie in front of a river with a bridge and greenery in the background.
A passive chemical sampling device © The South East Rivers Trust
  • 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.

A brick bridge with three arches spans over a gently flowing river in the southeast, surrounded by dense foliage and trees.
The River Blackwater in the River Loddon Catchment.

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/

Wetland Project Tackling River Pollution Receives Official Visit

Posted on by Sara Marshall

We recently welcomed the Secretary of State for Environment, Food and Rural Affairs Steve Reed MP, the Chairman of the Environment Agency Alan Lovell, and DEFRA Director of Water Sebastian Catovsky to our Chamber Mead wetlands. During their visit, the South East Rivers Trust team highlighted the multiple benefits of working with nature to tackle river pollution and other environmental issues.

Promoting Nature-Based Solutions

During the visit, we explained how nature-based solutions significantly reduce river pollution. Moreover, we found the new Government’s interest in these innovative approaches encouraging. To help our rivers recover more widely, we emphasised the need for the Government’s support to rapidly scale up these projects.

Group of four people walking on grass with trees in the background.
Environmental leaders visit Chamber Mead wetlands © South East Rivers Trust

Dr. Bella Davies, CEO South East Rivers Trust, said:“We are delighted to host the Secretary of State at the Chamber Mead wetland today. The wetland tackles sewage and urban road runoff pollution before it enters the Hogsmill River, which is a rare chalk stream, one of around 220 in the world, supporting a unique set of species dependent on the chalk-purified water. We are glad that the new Government sees the wide benefits of nature-based solutions and we urge them to take action to break down barriers to these kinds of projects and support organisations such as ours to deliver more at scale in the future.”

Governments Commitment to Water Quality

We’re pleased to hear that the new Government acknowledge the importance of improving water quality, which was highlighted in the King’s Speech, with plans for water industry reform. However, we emphasised the need for ambitious action on agricultural pollution, road run-off, and over-abstraction. We delivered this message directly to Steve Reed MP during his visit.

Exploring Chamber Mead Wetland

Steve Reed MP toured the Chamber Mead wetland with Rivers Trust CEO Mark Lloyd and SERT CEO Dr. Bella Davies. Alan Lovell, Chair of the Environment Agency, and Sebastian Catovsky, DEFRA Director of Floods and Water, also joined the visit. Chamber Mead demonstrates how nature-based solutions can vastly improve our waterways and combat river pollution. We have redirected the water from the Green Lanes Stream through a sediment trap and two wetlands instead of letting it run straight into the Hogsmill River. At the other end, we connected the wetland to the Hogsmill River downstream of the stepping stones. As they develop, the wetlands will provide diverse habitats and amenities to the Hogsmill Local Nature Reserve and improve water quality for a 200-metre section of this rare chalk stream.

Three people stand beside the Chamber Mead wetland testing the water quality.
Steve Reed MP on the waters edge at Chamber Mead wetlands © South East Rivers Trust

Impact on the Hogsmill River

The Chamber Mead wetlands help conserve the Hogsmill River, a rare chalk stream. This project cleans 250 million litres of water through natural systems, effectively combating pollution. The wetlands are part of a broader partnership between the Rivers Trust and The Coca-Cola Foundation.

Looking Ahead

The visit underscored the importance of these projects and the need for continued support. With the backing of the Government and our partners, we can achieve significant progress in restoring and protecting our rivers.

For more information on our projects and how you can get involved, visit the South East Rivers Trust website. Join us in making a difference for rivers across the South East.