Andrew Percy MP

Andrew Percy MP

Member of Parliament for Brigg & Goole and the Isle of Axholme

River Ancholme Pollution and Algae/Weed Growth – Update

Following residents contacting me regarding pollution and algae/weed growth issues in the River Ancholme near Brigg, I have been making representation to the Environment Agency and asked for an urgent update on what they were doing to address these issues.

The EA have now provided the below update following their investigations. I also recently joined Councillors Carl Sherwood and Rob Waltham to see the issues with the river first-hand.

As ever, I will ensure that any further updates are shared.

Environment Agency response:

River Ancholme Weed Growth 

The River Ancholme is managed by both our Waterways and our Flood and Coastal Risk Management teams for navigation and flood risk purposes. Our Contractors are currently undertaking the annual weed cut on the River Ancholme. They completed the Old River loop through Brigg last week and are now working on the main river, heading towards South Ferriby.

We are aware there is a considerable build-up of surface floating weed around South Ferriby. Due to lack of available water, we are unable to flush this weed out of the Ancholme at this time and due to the nature of the weed it will be difficult to manage with the weed boats; this type of surface weed tends to break up and is difficult for the weed boats to collect. The weed boats will try to improve the situation, but the ultimate solution will be to flush the weed out when water resources improve.

Algal blooms, and growths of other plants, occur naturally during spring and summer in response to rising temperatures and longer days. However, they have been more widespread this year due to recent fluctuating weather conditions, which have allowed them to thrive. This includes a massive growth of Azolla which floats on, and covers, the water surface. Algal blooms and higher plant growths of this nature are generally harmless with regard to human health but we would encourage anyone witnessing pollution to call our incident hotline on 0800 80 70 60.

Nitrate Vulnerable Zone and farming 

I can confirm that the River Ancholme is in a Nitrate Vulnerable Zone (NVZ). NVZs are areas designated as being at risk from agricultural nitrate pollution. They include about 55% of land in England.

Farmers and landowners must follow the NVZ rules when they use and store fertilisers and manures containing nitrogen. These rules contain limits on the amounts that can be used as well as when and where they can be applied. All applications must be planned in accordance with crop need and records made to show compliance. No fertilisers can be spread within 2 metres of a watercourse and other risks such as the slope of the land and weather conditions must be taken into account before spreading takes place. Farmers must also prove they have adequate storage to prevent the need for spreading in unsuitable conditions.

More information on nitrate vulnerable zones, including guidance for farmers and landowners, can be found at:

In 2018 the Farming Rules for Water were also introduced. These rules require farmers to manage their land to avoid water pollution. They provide a step by step checklist to make sure that fertilisers are spread to meet crop and soil needs. Other rules safeguard water quality by requiring farmers to judge when it is best to apply fertilisers, where to store manures and how to avoid pollution from soil erosion.

More information on the Farming rules for water can be found at:

Water Quality for the River Ancholme 

Under the Water Framework Directive (WFD), rivers are assessed on a number of elements on a scale from ‘High’ to ‘Bad’ status. In the River Ancholme (Bishopbridge to Humber), the most recent classification, shows the water quality elements Dissolved Oxygen, Ammonia, pH, Temperature all meet ‘High’ status. Invertebrate ecology also indicates ‘High’ status. Phosphate is classed as ‘Moderate’ status, which is of direct relevance to excessive growth of plants. These classifications are consistent with the first WFD assessment in 2009, indicating that water quality has remained stable since the late 2000’s.

Although Nitrate is not part of the WFD assessment, samples from various points along the Ancholme indicate that Nitrate concentrations have not increased over the same time period.

We are working with Anglian Water to influence action to reduce phosphate levels, with phosphate reduction schemes being required at 6 sewage treatment works in the Ancholme catchment before 2025.

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