Chemical pollution is one of the main causes of degradation and biodiversity loss in aquatic ecosystems.
But why are chemicals such a problem for salmon, trout and their waters?
More than 300,000 inventoried/regulated chemicals are currently used in industry, household and agriculture - which ultimately end up in our waters.
While European water bodies are contaminated with complex mixtures of ten thousands of chemicals, chemical status is defined on the basis of only 45 substances.
Concentrations of chemicals in the water may not reflect the true burden on river life, as chemicals may accumulate in tissues and be passed up the food chain.
Chemicals can harm river life lethally, where exposure causes direct death, and/or sublethally, where physiological pathways and natural behaviours are disrupted.
The Bakkavor Story
Concerning chemical signatures coupled with low Gammarus numbers and mayfly species richness (identified from our Riverfly Census project) led us to investigate below the Bakkavor salad washing factory on the River Itchen.
It was clear from our evidence that the current discharge permits were not fit for purpose to protect the river.
We took this case study on as part of our Water Action project, as we felt it highlighted a national problem. If policy is not stopping deterioration from chemicals on a protected SAC, SSSI river - what hope is there for other rivers?
The bed of a health chalk stream should show clear, un-sedimented gravel.
Instead below the Bakkavor site the bed was dominated by filamentous algae, with some fungal component.
In June 2018 S&TC made a formal notification of environmental damage to the Environment Agency (EA), pursuant to the Environmental Liability Directive, which forced the EA to undertake further research into the pollution coming from the salad washing plant.
The EA investigation exposed a number of issues with the site- including a pesticide threat. The monitoring found a suite of pesticides, dangerous to aquatic life, were being washed off salad leaves and entering the river via the discharge water.
Under continued pressure from S&TC, the EA begin requiring Bakkavör to monitor and report all pesticides which could present in their discharge, to levels the EA believed would not cause ecological damage.
In late 2020 Bakkavör announced that they would be closing the salad washing plant at Alresford on the Upper Itchen.
This closure should result in an end to significant chemical pollution and provide much needed respite for all biodiversity associated with the river.
However, our work is not over yet. Further pressure from S&TC to learn national lessons from this case study has resulted in the EA identifying 52 other discharge permits from food washing facilities, which could also be currently discharging pesticides unmonitored into rivers and groundwaters. The EA have committed to review all these licenses.
This successful outcome in one location provides a compelling case study, a proven model for eradicating chemical pollution and potentially significant reform of the EA licensing regime across the country.
Jan: Monitoring data obtained by Freedom of Information request shows neonicotinoid, Acetamiprid, above safe concentrations
Feb: Monitoring data obtained by Freedom of Information request shows neonicotinoid, Acetamiprid, above safe concentrations
March: Monitoring data obtained by Freedom of Information request shows neonicotinoid, Acetamiprid, above safe concentrations
April: Monitoring data obtained by Freedom of Information request shows neonicotinoid, Acetamiprid, above safe concentrations
July: Freedom of Information request indicates 36 other pesticides of concern, where current lab tests cannot monitor low enough to ensure they are not causing environmental damage
August: Bakkavor propose closing the salad washing plant on the headwaters of the Itchen
Chemicals - a national problem
We believe that businesses should not be allowed to damage the environment- they should return water in at least the same state as they receive it
Many historic discharge permits, for businesses still operating today, have not been revised and as a result are not fit for purpose to protect our waters.
Current monitoring* covers only a tiny fraction of the chemicals entering our waterways, ignoring biological impacts and mixture effects
SPEAR is a way of calculating chemical impact on rivers by looking at the presence and absence of water invertebrate species. Currently SPEAR is not used in the UK, but proposed boundaries to incorporate it into Water Framework Directive calculations do exist. Using our data, we are encouraging the use of SPEAR nationally in monitoring our watery places for chemicals.
*of priority substance-based chemical status according to the Water Framework Directive (WFD)
Chalkstreams should have their own classification under the Water Framework Directive
Our Bakkavor case study has demonstrated the value of invertebrate data - but for chalkstreams it has highlighted that current designations are not good enough to protect them from chemical damage.
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