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Phosphates on the Somerset Levels and Moors Ramsar Site

Information on Phosphate Mitigation in Mendip and progress on solutions.

Parts of the Somerset Levels and Moors are designated as a Special Protection Area (SPA) under the Habitat Regulations 2017 and listed as a Ramsar Site under the Ramsar Convention which protects wetlands. These are sites of national and international significance for wildlife.

On 17 August 2020 we received a letter from Natural England about the high levels of phosphates in watercourses affecting the condition of the  RAMSAR site. The same letter was also sent to the other Local Planning Authorities in Somerset. 

Natural England have advised that, in light of the unfavourable condition of the Somerset Levels and Moors Ramsar Site, before determining a planning application that may give rise to additional phosphates within the catchment, competent authorities should undertake a Habitats Regulations Assessment (HRA). In practice, this means many housing and other applications will need to include measures to reduce phosphates in water runoff and sewerage so it becomes 'nutrient neutral'. This is explained in the Natural England summary: Icon for pdf Nutrient Neutrality - non technical summary [138.83KB].

Somerset Phosphate Strategy

Phosphate Mitigation Solutions Report

The five Somerset Local Planning Authorities jointly appointed Royal Haskoning DHV (RHD) in March 2021 to develop a Phosphates Management Strategy to enable future development to take place within the catchment of the Somerset Levels and Moors Ramsar Site.

The report provides an overview  of phosphate mitigation solutions, potential costs, effectiveness and feasibility. It also provides estimates of the scale of mitigation required to meet current planned housing growth.

The report includes feedback from stakeholder workshops held in August  2021 and input from Natural England and Environment Agency. See video of the consultant workshop (Sept 2021

Icon for pdf Somerset Phosphate Mitigation Solutions Report [3.84MB]

The solutions report forms part of work to develop a Somerset wide Phosphate Strategy.  Joint work is continuing to develop a strategic approach to solutions such as catchment actions plans and a register of nature-based schemes. This will build on the recommendations and evidence in the solutions report.  However, the strategic solution is still being worked on and will not be available for some time.

Scope and Timescales on the strategy are set out in the Icon for pdf Phosphates Position Statement 26.05.2022 [78.29KB].

Updated Catchment Area Risk Map

A detailed map of the catchment areas at risk can be found on Mendip Maps 

Go to 'Environment and Planning' in the drop-down list of map categories and select both 'Somerset Levels and Moors Ramsar Risk Area' and 'Indicative WRC linked to RAMSAR'.  This will show the Water Recycling Centres (WRC) which fall outside the area of risk, but where sewage treatment outflows are within the risk area.

These locations will also be subject to phosphate mitigation requirements. 

An overview map of the areas at risk in Mendip can be found here: Icon for pdf Map of Area of Risk - 17.03.22 [11.68MB]

Overview maps which show the area of risk and treatment works catchments are below: 

Affected Development:

The types of development subject to phosphates related HRA within the area of risk include:

  • New residential units - including tourist accommodation, gypsy sites /pitches
  • Commercial developments - where overnight accommodation is provided
  • Agricultural Development - additional barns, slurry stores etc. where it is likely to lead to an increase in herd size
  • Anaerobic Digesters
  • Possibly some tourism attractions

Further information on how this will affect your application for planning permission or discharge of conditions, including how the Council will deal with your application and the additional information required can be found here: Apply for Planning Permission - Phosphates and the Somerset Levels and Moors Ramsar Site 

Since receipt of Natural England's 2020 letter, the four Somerset districts councils and Somerset County Council have been working hard to clarify the position on affected planning applications, lobby government and stakeholders and develop a phosphate strategy for Somerset. 

    Phosphate Budget Calculator

    The phosphate budget calculator can be used on proposed developments across Somerset. It will provide a transparent and rapid calculation of net phosphate loading from developments, including phosphate offsetting calculations for on or off site locations. The calculator has been approved by Natural England and it can therefore be used to provide a standardised and transparent decision making tool for the Local Planning Authority and Developers.

    It is requested that developers use the calculator to calculate the level of phosphates a proposed development will generate and for this information to be submitted as part of a package of information to support the planning application as it will need to form part of the HRA. A planning application will only be able to proceed to a positive recommendation if the proposed development is phosphate neutral or there is identified mitigation that can be secured. The calculator will remain under constant review and updated to ensure that it reflects any data changes - see Icon for pdf calculator updates [39.71KB].

    A video has been prepared which provides a step by step guide to help you use the calculator.

    Phosphorous Budget Calculator 

    View the Phosphates Guidance Video

    Wessex Water Maps of WRC catchments and nutrient permit information - see 'developers' tab

    Government and Natural England Advice

    A government statement (DEFRA) on nutrient neutrality was published on 16th March 2022  Nutrient pollution: reducing the impact on protected sites - GOV.UK ( Letters between the Somerset LPA's and government can be found here Icon for pdf Minister Pow - Somerset Letter - 28th March 2022 [112.4KB].  The latest response from DEFRA is 28th March 2022.  Natural England released a new national approach, tools and guidance on nutrients mitigation on 16th March 2022.  It has been agreed the existing approach and phosphate mitigation calculator should continue to be used while this is evaluated.  

    Natural England Advice

    Wessex Water Information

    Legal Advice

    The Council has sought legal advice from Counsel on some key issues. This includes advice sets out that 'pre-commencement' conditions relating to affected developments within the catchment area, cannot be discharged until an HRA has been undertaken. The Council and Natural England have also agreed advice around 'permitted development'.

    Further Information and Press Releases

    We will update this page with further information as soon as we are able and we will be regularly updating this webpage to keep you informed of progress.

    If you have any questions in the meantime, please contact