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Phosphates on the Somerset Levels and Moors Ramsar Site

Background to Phosphates on the Somerset Levels and Moors

The Council is committed to development only taking place if it is sustainable development that includes relevant environmental protections. Somerset West and Taunton Council (SWT) has recently declared an ecological emergency complementing the climate emergency declaration made in February 2019.

The quality of the natural environment in our area is of a particularly high standard. Parts of the district fall within the Somerset Levels and Moors. Within this area various locations are of national and internationally significance for wildlife. Thus, 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.

On 17 August 2020 we received a letter from Natural England about the high levels of phosphates in the Somerset Levels and Moors. The same letter was also sent to the other Local Planning Authorities in Somerset.

In light of a court Judgement (known as Dutch N), Natural England have advised SWT 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).

The types of development 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

The Development Challenge

The need for nutrient neutrality is presenting a challenge for development and holding up progress on planning applications across Somerset.

New development is vital for Somerset West and Taunton. With a population projected to reach 134,500 Source: Office for National Statistics/Somerset Intelligence by 2031, the need for new housing, including affordable homes, is well established, as is the disproportionate effect on small and medium size enterprises (SMEs). With future developments expected to be one of the contributors to phosphate pollution, developers in the affect River Tone catchment area face a significant challenge in managing phosphate outputs from their sites. 

SWT Response

Since receipt of Natural England’s letter, the four Somerset districts councils and Somerset County Council have been working hard to minimise delay and uncertainty around planning applications following recent guidance over excessive amounts of phosphates in the Somerset Levels and Moors.

This work includes a county-wide nutrient strategy to identify both short term solutions to help clear the current backlog of planning permissions and longer-term solutions to address the existing and future growth commitments.

In addition, Somerset West and Taunton Council has been progressing an Interim Phosphates Mitigation Strategy, further information on which is provided below.

The Council has sought legal advice from Counsel on some key issues. A Legal Summary of the advice received is available. This advice sets out that ‘pre-commencement’ conditions relating to affected developments within the catchment area, cannot be discharged until an HRA has been undertaken.

There is further guidance provided in the Discharge of Conditions Guidance.

Somerset Levels and Moors Phosphate Mitigation Solutions (February 2022)

In collaboration with the other Somerset Authorities, consultants were appointed in May 2021 to provide technical support and develop mitigation solutions following the Natural England letter to respond to the phosphate issue affecting the Somerset Levels and Moors Ramsar site. 

The purpose of the commission was to investigate a range of matters. These included the review of the geographical extent of the catchment area in Somerset, to make improvements to the phosphate calculator.

Nutrient neutrality requirements are complex. Any mitigation approach that a developer takes should be specific to the waterways they are most likely to affect. The Somerset Levels and Moors is connected to 3 river catchment areas: The River Tone, Parrett and Brue. Developers must make sure that their phosphate offsetting efforts occur within the same river catchment as their developments. As such another aim of this commission was to provide information on potential mitigation options that could be delivered within the specific affected river catchments of the Rivers Tone, Parrett and Brue.

The Solutions Report can be used by developers to explore potential phosphate mitigation options for new development.

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.

On 16 March 2022, this Council, along with others within Somerset, Devon and Dorset, received a letter from Natural England that confirmed the River Axe Special Area of Conservation (SAC) was in an unfavourable condition and therefore local planning authorities would need to consider the adverse impacts of new development on the designated habitat site.

The advice required that the local planning authorities as the Competent Authority under the Habitats Regulations Assessment to consider the nutrients impacts of any new plans and projects and whether those impacts may have an adverse effect upon the integrity of a habitats site that requires mitigation through nutrient neutrality.

The advice is relevant to all types of overnight accommodation including new homes, student accommodation, care homes, tourism attractions and tourist accommodation and permitted developments (which gives rise to new overnight accommodation) under the Town and Country Planning (General Permitted Development) (England) Order 2015.

Within Somerset West and Taunton, this advice applies to a small area within the environs of the Blackdown Hills. Further information can be found on the South Somerset District Council website.

This Council along with others within Somerset, received Additional National Advice from Natural England.  The Natural England documents comprised:

Provisional national tools and methodologies

Following the release of additional national advice from Natural England on matters relating to nutrient neutrality on the 16 March 2022, this is a joint statement by the Somerset planning authorities, Natural England, the Environment Agency and Wessex Water.

With regard to nutrient neutrality for development proposals that could affect the Somerset Levels and Moors Ramsar Site, the requirements of the Natural England advice issued on the 16 March 2022 apply to areas of risk identified in the recently updated catchment map published by the Somerset planning authorities on 16 March 2022. 

However, until advised otherwise: the Natural England generic Nutrient Neutrality Methodology and catchment calculator should not be used. They are provisional national tools and methodologies and will be reviewed locally before any changes are made to the existing approach.  Accordingly, decisions on affected planning applications will continue to be based upon the use of the Somerset Phosphate Calculator.

In addition to the documents provided by Natural England, the Chief Planner for the Department for Levelling Up, Housing and Communities (DLUHC) also wrote to all local authorities on 16 March 2022 providing an update upon DLUHC’s position and support available for each catchment.

On behalf of all the Somerset Authorities, as lead authority for the Somerset Levels and Moors, Somerset West and Taunton submitted a request for further funding support through the Nutrient Pollution Mitigation Fund.   

Within the Bill there are provisions which amend the HRA process, so that the upgrades to plants / Wastewater Treatment Works (WwTW’s) to 0.25mg/l are deemed certain when calculating phosphate mitigation post 2030. ​ There are exemptions to the 0.25mg/l where plants / WwTW’s serve a population below 2,000 people.  All these measures must be agreed by Parliament and therefore they are subject to change. There is no certainty on how long it will take however, at the time of writing, they are expected in Spring 2023.​ Further details were about the Levelling-up and Regeneration Bill are available on the UK Parliamentary website.

Defra Nutrient Mitigation Scheme

This Council along with other local planning authorities within Somerset, have received details of this national scheme which shall be funded by Defra/DULHC and implemented by Natural England. The scheme will enable creation of nutrient mitigation habitat which will be valued as nutrient credits. Natural England will then issue nutrient certificates to eligible developers to inform planning applications in areas subject to nutrient neutrality advice. 

In their November 2022 update, Natural England is currently identifying places most likely to be suitable for nutrient mitigation provision and, from December 2022, will approach landowners in a targeted way to invite them to offer their land as potential sites for nutrient mitigation. Natural England state that they will launch the scheme by inviting applications from developers for mitigation credits before the end of March 2023. Further details about the Natural England Mitigation Scheme are available in their update.

SWT Nutrient Neutrality Strategic Mitigation Scheme

Ministerial Statement 20 July 2022

The announcement of the Defra Nutrient Mitigation Scheme 20 July 2022 was accompanied by the following Written Ministerial Statement. It outlines a package of further measures to tackle nutrient pollution. It also states that:

  • There will be a new legal duty on water companies in England to upgrade wastewater treatment works in ‘nutrient neutrality’ areas to the highest technically achievable limits by 2030 - the Government will be tabling an amendment to the Levelling Up and Regeneration Bill.
  • The Government will also be bringing forward proposals to ‘reform’ the Habitats Regulations – further details are awaited.
  • DLUHC will revise planning guidance over the Summer to reflect that sites affected by nutrient pollution forming part of housing land supply calculations are capable of being considered deliverable for the purposes of housing land supply calculations, subject to relevant evidence to demonstrate deliverability.
  • Habitats Regulations Assessment provisions apply to any consent, permission, or other authorisation, this may include post-permission approvals; reserved matters or discharges of conditions. Planning guidance will be amended to confirm this.

DLUHC Chief Planner Letter 21 July 2022  

The announcement of the Defra Nutrient Mitigation Scheme on 20 July 2022 was accompanied by the following letter from DLUHC. It gives further details of the package of measures announced by Government to tackle nutrient pollution.

  • It confirms that the national nutrient mitigation scheme will be optional and open to all developers, while ensuring SMEs are prioritised.
  • The national scheme is intended to ‘dovetail’ with existing private and LPA-led nutrient mitigation schemes. It is envisaged that the scheme will enable LPA’s to grant permission subject to conditions or obligations securing mitigation and phasing development if needed.
  • As a result of the new legal duty on water companies, the pollution levels after 2030 via wastewater treatment works will be much reduced and so a lower level of mitigation will be required, thus reducing the overall mitigation burden on housing developments.
  • DLUHC will make clear in planning guidance that judgements on deliverability of sites should take account of strategic mitigation schemes and the accelerated timescale for the Natural England’s mitigation schemes and immediate benefits on mitigation burdens once legislation requiring water treatment upgrades comes into force.  

The letter also provides clarity on various matters and re-states that Habitats Regulations Assessment provisions apply to any consent, permission, or other authorisation, this may include post-permission approvals; reserved matters or discharges of conditions.  

DLUHC Chief Planner Letter 21 July 2022

Letter to Council Leaders from Secretaries of State for DLUHC and Defra 21 July 2022

The following letter to Council Leaders of Local Authorities affected by nutrient pollution was received on 21 July 2022. This letter reiterates the package of measures announced by Government to tackle nutrient pollution. It further states that, longer term, the intention to ‘reform’ the Habitats Regulations so that impacts on protected sites are tackled up front, focusing on what is best for bringing sites back into favourable status.

Letter to Council Leaders

Direction by the Secretary of State to Natural England: 28 July 2022

This direction to Natural England on strategic mitigation scheme is available at GOV.UK - Nutrient pollution: Direction to Natural England on strategic mitigation schemes.

As the Local Planning Authority (LPA) there is no statutory requirement for SWT to intervene to deliver phosphate neutral development in the District. Notwithstanding this, SWT has been working hard to find solutions for development to proceed. As an interim solution, SWT has committed £2m to forward fund the delivery of an interim strategy of measures. The purpose of these measures is to generate phosphate credits (known as ‘SWT P credits’) that can be used to unlock some of the planning applications that are held in abeyance.

 SWT P Credits are being generated by the following projects:

  • Utilising Council Assets (e.g. improved water efficiency of Council owned properties);
  • Land Use Measures (e.g. wetlands); and
  • Working in partnership with the Private Sector (e.g. fallowing land).

 The Council are doing this to facilitate sustainable development, to minimise impact on SME’s; to help meet the requirement to maintain a 5-year housing land supply; and to meet our wider housing duties.

The initiative supports various Council ambitions associated with: Our Environment and Economy; Homes and Communities and an Enterprising Council. These are set out in the Corporate Strategy 2020-2024

On 9 November 2022 Natural England confirmed their support of SWT's Interim Phosphates Interim Strategy as set out in the Standard Appropriate Assessment of the Strategy.

SWT Phosphate Credit Scheme

In total, SWT has estimated that the SWT interim phosphate mitigation strategy will generate a minimum phosphate offset of 75.5 kg/year equating to 75.5 SWT P credits (1 credit = 1 kg of phosphates removed per year).

On 21 July 2022, the Phosphates Planning Sub Committee agreed the costs of the SWT P credits as set out in this report. This report also provides the most up-to-date position on the progress of the interim strategy.

The cost of an SWT P credit will be c. £55,000.00 per credit.

We are aware that some developments will not require a whole SWT P credit (1kg of phosphates removed per year) and as such SWT P credits will be made available in tenths e.g. an applicant will be able to secure 0.1 P credit.

SWT P credits will only be available as and when associated mitigation projects are put in place. As such it is envisaged that SWT P credits will become available in ‘rounds’. 

SWT P Credits Expressions of Interest:

SWT recently carried out a consultation exercise to survey all applicants with a planning application currently held in abeyance as a result of excessive levels of phosphorus in the Somerset Levels and Moors. 

One of the key aims of this survey was to gauge the level of interest in the SWT P Credits generated through the Council’s interim phosphate mitigation strategy. 

We have prepared a summary of the findings of this survey.

How to apply:

Do not approach us, we will approach you.

It is unlikely that there will be sufficient P credits at present to ‘unlock’ all planning applications held in abeyance and as such, in February 2022 the Phosphates Planning Sub Committee (set up to govern the interim strategy and on-going monitoring arrangements), agreed a set of recommended criteria for SWT P credit allocation.

In summary, the criteria prioritise minor application for housing development (i.e. C3 use classes and traveller sites). Applications that exceed affordable housing policy and/or relate to applications for the discharge of conditions will be afforded more weight and therefore will be placed at the top of the priority list. Applications for outline planning permission will not be prioritised for the first round of SWT P credits.

Further information on the prioritisation process and associated criteria can be found within the report to Phosphates Planning Sub-Committee, available on our website.

We have prepared a provisional list of planning applications that are currently likely to be eligible for the first round of SWT P credits once available are listed in this document.  

Next Steps:

As and when SWT P credits become available, SWT will be in contact with applicants that have expressed interest, in order of priority as agreed. We will confirm whether credits are available to meet the anticipated need and at what cost.

This link includes more information as to how SWT envisages the SWT P Credit process progressing please see this document.

Please note that all applications for SWT P Credits will be required to provide the following:

  1. Confirmation of the phosphate budget for the proposed development and the number of SWT P credits required to ensure phosphate neutrality. This can be done using the Somerset Phosphate Budget Calculator.
  2. A Shadow Habitats Regulations Assessment (sHRA). In order to assist the preparation of an sHRA, SWT has prepared a template document that can be used.

You may wish to consider the above in advance of any application for SWT P credits in order to speed up the process. Please note you may also wish to seek technical support in completion of the above.

Unfortunately, SWT is unable to complete any of the above on behalf of applicants.

All applications in receipt of SWT P credits will be required to complete a Section 106 agreement to secure this mitigation. In order to assist this process, we have produced a template Section 106 agreement.

Contact Us:

Should you have any questions or comments related to the acquisition of SWT P credits, please contact us via email at:

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.

The calculator will also be updated in due course to take into account planned upgrades to Waste Water Treatment Works (WwTw) within Somerset by Wessex Water.

The calculator was updated on 8 March 2021 with the following amendments:

  • Correction of a glitch relating to the runoff coefficients of meadow / natural grassland
  • Removed wetland land use from the proposed land use options in stage 3 and replaced with an option to input bespoke values for wetland or SuDS following guidance by natural England that the previous value is no longer endorsed by them due to uncertainties
  • Definitions have been added for all of the land uses
  • Land uses with the same coefficients have been collated where possible
  • The runoff coefficient for a bog changed from 0.00 to 0.02 kg/ha/yr
  • Permit limits for some Wastewater Treatments Works were updated following advice from the Environment Agency
  • Various dwelling types and the appropriate occupancy rates have been added

We aim to implement further changes to the Phosphate Calculator before Easter 2022, in a coordinated way with the other local authorities in Somerset and with updated advice from Natural England.

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

Next Steps

Once you have used the calculator and have an understanding of how much mitigation a development will require, you will then be able to consider what your options are for mitigation. In order to help you move forward, some guidance has been produced which includes: