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Ceredigion County Council website

Phosphates on the Teifi River Special Area of Conservation

The Council is committed to development only taking place if it is sustainable development that includes relevant environmental protections.

The quality of the natural environment in our area is of a particularly high standard and various locations are of national and international significance for wildlife. Thus the Afon Teifi is designated as a Riverine Special Area of Conservation (SAC) under the Conservation of Habitats & Species Regulations 2017, as amended (“The Habitat Regulations”).

In January 2021 Natural Resources Wales (NRW) published new targets to reduce river phosphate levels in SAC across Wales.

The review followed evidence from the Joint Nature Conservation Committee that warmer and drier weather, predicted as a result of climate change, could reduce river flows during the summer and therefore increase phosphate concentrations. It is also based on new evidence about the damaging effects of phosphates to water ecosystems and species.

At present, over 60% of waterbodies in Wales fail against the tighter targets, and Welsh local planning authorities are being asked to take more action to avoid further deterioration of the environment. It means any proposals for development within SAC river catchments - in particular those that will generate increased volume or concentration of wastewater - must now prove that the design will not contribute to increased phosphate levels.

The Afon Teifi, is a Special Area of Conservation and is failing NRW’s targets for phosphate compliance. The NRW Compliance Assessment report of Welsh River SACs against Phosphorus Targets report can be accessed here. Since late Autumn 2023, NRW have been undertaking permit reviews of wastewater treatment works (WWTW’s) with dry water flows over 20 m3 situated within the Afon Teifi SAC catchment, for assessment and determination of new permitted target limits for Phosphorous to ensure compliance of treated effluent entering the river. At present a number of WwTW’s within Ceredigion have now been reviewed and issued with updated permit values for Phosphorous levels. We are pleased to announce that from those permits recently updated, several have been issued which will enable some development to come forward within specific wastewater treatment work catchment areas namely:

  • Llandysul
  • Tregaron
  • Lampeter
  • Llanddewi Brefi
  • Llangybi, Cellan
  • Llanybydder
  • Henllan
  • Llechryd
  • Beulah
  • Pontrhydfendigaid

However, the process is still ongoing, and we would advise that at this time should development come forward in the as yet non reviewed wastewater treatment work catchment areas there remains limited capacity to connect to the public sewerage system in line with NRW’s planning guidance which can be accessed here. Thus, alternative solutions must be found that will meet the new targets, either by being phosphate neutral or bettering phosphate levels. You can view a map of the river catchment areas here.

In light of a court Judgement (known as “The Dutch Case”), NRW have advised Ceredigion County Council that, in light of the unfavourable condition of the Teifi SAC, before determining a planning application that may give rise to additional phosphates within the catchment, competent authorities should undertake a Habitats Regulations Assessment (HRA).

Ceredigion County Council is a ‘competent authority’ under the Habitats Regulations, and thus means the council is legally required to assess the potential impacts of projects and plans, on internationally important sites which include the Teifi SAC. In its role as competent authority, the council must carry out a ‘Habitat Regulations Assessment’ on any relevant planning application that falls within the boundary and catchment areas as shown on the plan (for which there is a link above). Where there is a ‘Likely Significant Effect’, the council must carry out an ‘Appropriate Assessment’ in order to determine, with scientific certainty, that there would be no ‘Adverse Effect on Integrity’ on the designated site from the plan or project, either alone or in combination with other plans and projects.

The council takes this into account when considering whether planning permission can be granted. If it cannot be proven that there would not be an adverse effect on integrity, then planning permission cannot be granted without further stringent consideration under the Habitats Regulations. NRW is a statutory consultee on appropriate assessments and provides advice to competent authorities in relation to sites designated such as SACs. Local Planning Authorities must have regard to the advice given by NRW when making planning decisions (for both individual developments and local development plans (LDP). NRW’s advice should be given considerable weight, but competent authorities are entitled to depart from it where they can give cogent reasons for doing so.

The types of development impacted by this requirement include (but are not limited to):

  • New residential units - including tourist accommodation, gypsy & traveller sites /pitches, student accommodation, care homes etc.
  • Commercial developments where overnight accommodation is provided.
  • New large commercial or industrial developments where customers will be attracted from outside of the catchment such as large retail sites, conference facilities, or major tourist attractions
  • Some types of Agricultural Development - additional barns, slurry stores etc.
  • Prior Notifications of agricultural development where, as a result of the development, the amount or concentrations of wastewater discharge is increased.
  • Anaerobic Digesters.
  • Tourism attractions.
  • Some forms of permitted development to an existing property (e.g. extensions) that increases the volume of foul drainage (e.g. as a result of increased occupancy).

Further information on the types of development impacted by this direction and those which are not, is available on the NRW interim planning guidance documents for which there are links below.

Natural Resources Wales / Tighter phosphate targets change our view of the state of Welsh rivers

What action have we taken?

We have written to Welsh Government outlining our concerns about the impact on development and have made clear that we want to find a solution as quickly as possible. We have also taken a number of proactive steps:

  • We have produced a Phosphate Calculator for developers to calculate the level of phosphates their development will generate. This has been modelled specifically with data for Ceredigion.
  • We have produced a Technical Guide – detailing all of the calculations and data inputs used in the calculator.
  • We have produced comprehensive Mitigation Guidelines that explain the most effective types of mitigation that could be utilised in Ceredigion.
  • We have established a Nutrient Management Board (NMB) for the river Teifi. This board will be responsible for producing a Plan to improve the condition of the river and to facilitate nutrient neutral development to proceed. Further details of this Board, including a webpage displaying live updates will be posted on this page when it becomes available.

Next Steps

  • We have now established a Technical Advice Group to provide evidence review, scenario modelling and proposals that will be presented to the Nutrient Management Boards for approval.
  • We have also established a River Stakeholder Group, operating as one cross-region group. Membership of this group is open, and we welcome all contributions to help facilitate constructive and lasting change for river health. For further details of upcoming events, meetings and to also receive details about joining information please contact the Nutrient Management Board Support officer
  • The challenges of addressing phosphate pollution are complex, and there is no easy solution. Long lasting solutions will require collaboration with neighbouring Local Authorities, Dŵr Cymru Welsh Water, the farming sector, NRW, Welsh Government and environmental bodies. CCC actively collaborate and share information will all parties on a regular basis via regional and all-Wales meetings.
  • A Strategic Mitigation programme that maximises mitigation and delivers the benefit of that via a credit exchange is being explored. This will remove many of the mitigation barriers that developers are having to address.

We recognise that this situation will be frustrating for developers - we want to work with you to find solutions that improve the condition of our rivers, that are feasible and can be implemented quickly and successfully. We want to engage with a wide range of people representing homebuilders, employers, the farming community, residents, environmental groups and more to discuss these issues.


Our nutrient budget calculator is now live.

This tool enables you to calculate the phosphate levels that a proposed commercial and residential development in Ceredigion could produce.

This is a free resource, designed specifically for West Wales, it will support you to understand the impact of your development and will allow you to confirm the proposed development’s phosphate budget and consider mitigations.

We have produced a Calculator Guidance document and a Calculator Technical Review as an instructional guide to help you use the calculator which also explains where data has been gathered from and how calculations have been deduced. Separate mitigation guidelines have been produced for each river catchment. These can be accessed here:

West Wales Mitigation Guidelines

Please use the West Wales nutrient budget calculator to assess whether development will increase nutrient loading to a European site/SAC and whether the development is within a catchment that drains to an affected European site.

If the answer is yes to the question/s noted below:

1 or

2 and 3 or

2 and 4

  1. Whether the development is within a catchment that drains to an affected European site.

  2. Whether the receiving Wastewater Treatment Works discharges to an affected European site.

  3. Whether the development will lead to an increase in ‘overnight stays’.

  4. Whether the development will lead to an increase in the number of customers/users or employees coming into the catchment of the SAC river from outside of the catchment to work (in this context a user is defined as a person who may use a service or facilities provided by the development without being directly considered as a customer).

How it works

Simply input the information specific to your development, and site, into the calculator and work through the stages - instructions have been provided to help you.

The calculator will produce a value of phosphorus in kg per annum. The end value can be used to help you consider your phosphate mitigation options. The calculator will not estimate the amount of land required for any form of mitigation due to the numerous variables in nature-based solutions that may vary depending on proposed maintenance, maturity and site-specific conditions.

The mitigation guidelines, will further assist you in the selection and implementation of mitigation options.

Although it is not required that you use this calculator, we strongly encourage you to do so. Any applications submitted using alternative calculators will be subject to additional scrutiny to determine their relevance to conditions in the county.


The Council, does not accept liability for any direct or indirect damage, loss or inconvenience caused by the downloading and use of this phosphate calculator from the Council’s website.

Please refer to the Technical Guide for an explanation of the data sets and calculations used in the calculator. If you have any comments, please let us know by emailing The calculator will be subject to periodic reviews and updates to ensure it is based on the best available evidence and accurately reflects the local conditions.

Mitigation Measures

Mitigation measures need to reflect site specific circumstances, and have an understanding of the source of that phosphate pollution.

Dŵr Cymru Welsh Water are in the process of undertaking a review of Phosphate (P) sources. This information will help shape the right mitigation in the right place. You can access the source apportionment data here.

More research is required on the efficacy of different types of mitigation options.

Any mitigation measures intended to avoid or mitigate potential phosphorus impacts must demonstrate that they are based on ‘best available evidence’, will be effective ‘beyond reasonable doubt’, are based on estimates that are ‘precautionary’, and can be secured ‘in perpetuity’ (80-125 years).

The proposed measures must also be legally enforced.

For each measure, we need to receive information:

  • detailing how the measure(s) would avoid or reduce adverse effects on the SAC (considering the predicted duration of the effects).
  • demonstrating how the measure(s) would achieve nutrient neutrality.
  • confirming how the measure(s) will be implemented, and by whom
  • detailing how the measure will be maintained and who will be responsible for maintenance.
  • showing how the measure will be monitored to ensure it is effective.

Further information on mitigation measures can be found in the latest NRW Phosphate Planning Advice.

We recognise that this situation is frustrating for developers - we want to work with you to find solutions that improve the condition of our rivers, that are feasible and can be implemented quickly and successfully. We want to engage with a wide range of people representing homebuilders, employers, the rural land use sector, residents, environmental groups and more to discuss these issues.

Ceredigion County Council is working proactively to minimise disruption and provide a solution to this unprecedented issue. We are operating at the forefront, planning strategically and recognise the necessity for fast and effective action, setting an example for the rest of Wales.

NRW have started issuing their review of wastewater treatment works (WwTW) permits. A backstop P limit is being applied to sites that previously had none in the past. Tighter P limits may be placed on WwTW permits where a limit is already present. There may be no change to existing P limits at certain sites. The new backstop limit of 5mg/l applies to sites with a dry weather flow of <20m3/day.