Nutrient Neutrality FAQs

We have updated the FAQs and will be adding more content in the coming months. We are keen to hear your thoughts and comments, especially if there are any additional questions you want us to help answer. Please get in touch with [email protected] or [email protected]


What is the issue?

Nutrient pollution is a big environmental issue for many of our most important places for nature in England. In freshwater habitats and estuaries, increased levels of nutrients (especially nitrogen and phosphorus) can speed up the growth of certain plants, impacting wildlife. This is called ‘eutrophication’ and it is damaging protected sites. As such, some sites are classified as being in ‘unfavourable condition’.

These internationally important sites are protected under the Habitats Regulations 2017, and termed “Habitats Sites” in the NPPF. Competent authorities, such as local planning authorities must assess the environmental impact of planning applications and local plans which may affect these sites. Local Planning Authorities (LPAs) can only approve development if they are certain that it will not have an adverse effect on the site.

Natural England (NE) has previously advised 32 LPAs that, where protected sites are in unfavourable condition due to excess nutrients, development should only go ahead if it will not cause additional pollution to sites. In March 2022, Natural England advised a further 42 Local Planning Authorities that their areas are covered by this advice.

The advice from Natural England means that new residential development must achieve ‘nutrient neutrality’. It has had a significant negative impact on the number of homes granted planning permission in areas already affected.

 What is Nutrient Neutrality?

Development achieves nutrient neutrality when the nutrient load created through additional wastewater (including surface water) from the development is mitigated. By designing development alongside suitable mitigation measures, additional nutrient loads can often be avoided or mitigated. This approach is called ‘nutrient neutrality’. It essentially allows developments to be permitted without impacting on the condition of protected sites.

Different LPAs are affected to different degrees – some will have only a small part of their area affected, and others will be impacted to a much greater extent.

 Why is this happening?

Pollution from nutrients can arise from the way that land is used in areas close to water bodies (known as ‘water catchments’). Where sites are already in unfavourable (poor) condition, extra wastewater from new housing developments can make matters worse. Pollution most typically arises from:

- Agricultural activity - fertilisers, animal waste, slurry

- Use / occupation of buildings (homes especially) – untreated or partially treated sewage and wastewater entering rivers over and above the limits that water companies’ permits allow

- Surface water ‘run-off’ - from development

  What does this have to do with the Planning system?

Sewage and wastewater from development usually results in an increase in nutrients being discharged into water courses. Wastewater treatment works (WwTWs) do not remove all the nutrients from foul water drainage before it is discharged into the environment.

Natural England (NE) has produced a map of water catchments with protected sites affected by nutrients where new development must be considered carefully. NE has reminded LPAs that the Law requires that planning permission can only be given for developments in these areas where a Habitats Regulations Assessment (HRA) demonstrates a neutral impact on current nutrient levels in the catchment.

 Why is this suddenly causing LPAs and developers an issue?

A legal case in the Court of Justice of the EU in 2018 (known as the ‘Dutch Nitrogen Case’), means that measures to mitigate the impact of nutrients in water bodies can no longer be postponed into the future. NE has advised Competent Authorities that mitigation measures forming part of a HRA must demonstrate no adverse effect ‘beyond reasonable scientific doubt’ and that the benefits of the mitigation measures must be ‘certain at the time of the Assessment’ before planning permission can be given. Any development that will have an adverse effect will need to provide suitable mitigation. This means that until mitigation is available, development in the areas affected will need to be carefully considered.

What are the main issues for LPAs?

This issue affects plan-making and decision-making activity. It is very new and whilst there is lots of advice about the cause of the problem and what needs to be done, we are still learning about how to solve the problem and how to deal with the planning issues this situation presents in the short to medium term.

This issue affects different places in different ways and the solutions (that will allow development to be permitted) take time to implement - even in places that have been working with this issue for several years). There are some emerging strategies for responding to the issue and each response is specific to the specific issues in each catchment affected. This makes ‘blanket’ solutions difficult to create and many of the solutions take several years to establish. As a sector we are not currently able to rely confidently on a set of mitigation measures.

 What is Planning Advisory Service doing?

PAS support is starting by creating spaces for LPAs to come together to discuss how this issue is affecting them – we have run a series of events in April and May 2022. The objectives of the PAS support are to:

-      help LPAs understand and quantify the overall impact of this issue on their local plan and decision making.

-      encourage and facilitate a coordinated, strategic, and consistent response within each catchment affected so that measured short and medium-term responses can be devised.

-      help LPAs work with communities and stakeholders to design developments alongside suitable mitigation measures.

-      understand the role of LPAs in working with stakeholders contributing to the longer-term aim of restoring protected sites to favourable condition.

Levelling Up & Regeneration Bill

When will LPAs be able to rely on the new 2030 duty for the purposes of plan-making and decision-making?

The obligated upgrades to WWTW required by the end of 2030 will provide clarity from the point of the LURB measures coming into force. This will reduce the overall mitigation burden on housing developments coming forward in nutrient neutrality catchments. 

Once the LURB reaches Royal Assent, it enables decision-makers to be confident the upgrades will be in place by 2030, enabling them to treat as certain the lower levels of pollution after 2030 as part of a HRA. This reduces the mitigation requirements for the in-perpetuity period, as the current (higher) levels of pollution need only be mitigated until 2030 (or earlier if the upgrades take place sooner), with the lower pollution level needing to be mitigated thereafter.

The Government 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. DLUHC will revise planning guidance to reflect that affected sites which form 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. It will be for decision takers to make judgements about impacts on delivery timescales for individual schemes in line with the National Planning Policy Framework.

 How do I know which WwTW will be upgraded?

The full list of wastewater treatment works being upgraded under the new duty has not yet been confirmed. We will signpost this information on our website when it is known.

 Where will the TAL duty apply?

The amendments apply only in England and to any water company which is wholly or mainly in England.

Can the reduction in nutrient levels by water companies be counted as mitigation to offset a development?

No, this cannot be counted as mitigation for the purposes of HRA. The amendment reduces the level of pollution from a wastewater treatment works and this is factored into the baseline for HRA. In effect this lowers the overall nutrient burden from a development and means that less mitigation is needed.

 How is mitigation calculated to account for different levels of nutrients before and after the upgrades to wastewater treatment works?

Mitigation will be calculated at a higher rate for the period prior to any upgrades i.e., in the period up to 2030. Thereafter, mitigation will be calculated at a lower rate in perpetuity. Nutrient credits will need to cover both the higher load up to 2030 – possibly with temporary credits - and the remaining load thereafter – possibly with permanent credits. 

How are LPAs expected to secure the varying levels of mitigation required over time for a development e.g., following upgrades during AMP 8 and again in 2030?

It’s not clear yet how the sale of credits will work for mitigation providers and therefore how credits might be secured for different levels/time periods. We anticipate LPAs will develop s106 agreements to deal with these scenarios and we will look to share examples of emerging best practice through the nutrient network. 

National Nutrient Mitigation Scheme

What is the Scheme?

Natural England is establishing a scheme to provide mitigation that complements other existing and planned mitigation. Defra and DLUHC are investing up to £30 million in the Scheme over the next three years.

When will the Scheme launch?

The scheme was announced by Government in July 2022 and is expected to be formally launched by inviting applications for credits from developers before the end of March 2023. Details of how the scheme will work in practice will be available at scheme launch.

 How is the Scheme design progressing?

Natural England has been working with partners in impacted catchments to identify and develop additional mitigation projects. The first projects are currently being negotiated with two partners in the Tees catchment. Investment in feasibility studies in five further catchments is underway to determine the schemes next mitigation sites. 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. 

 What is the latest on the Scheme?

From December 2022, Natural England will approach landowners in a targeted way to invite them to offer their land as potential sites for nutrient mitigation. These sites will start to provide the mitigation needed by LPAs and developers, and we will expand across the country to facilitate building thousands of new homes as well as making a major contribution to nature recovery through the creation of new wetlands.

Natural England will invite applications from developers for mitigation credits in the Tees before the end of March 2023.

 Who will be able to buy credits?

Credits will be offered in batches which any developer can apply for. Where demand for credits exceeds supply, applications will be prioritised.  Information for developers on credit availability and price will be released ahead of the first credit sales.

 How will the Scheme operate?

Details of how the scheme will work in practice will be available at scheme launch. 

By reserving credits (via nutrient certificates issued by Natural England) developers provide assurance to LPAs that they can satisfy nutrient neutrality planning conditions. This will enable LPAs to grant permission subject to conditions or obligations securing mitigation and phasing developments (if needed) so that mitigation is operational and in place, prior to any nutrient pollution being discharged. Once payment for credits has been made, and any related planning conditions discharged, new homes can be occupied.

The Department for Levelling Up, Housing and Communities (DLUHC) will update the Planning Practice Guidance on the application of the Habitats Regulations Assessment in this regard and consider additional revisions as necessary.

Local Plans

What help is available from Government in the short-term for authorities with local plans at an advanced stage?

DLUHC is open to discussions with individual LPAs where there are significant and immediate pressures e.g., 5-year housing land supply, Housing Delivery Test, funding for major infrastructure. LPAs should compile evidence of the nature and scale of Local Pan implications and submit the analysis to the DLUHC mailbox. The Department will keep a record of evidence submitted by LPAs, and any subsequent discussion, to support the ongoing review and future advice to Ministers.

What is the Government doing to make allowances for a temporary reduction in housing delivery?

DLUHC is actively considering how to deal with difficulties regarding housing delivery and the Housing Delivery Test. No decisions have been taken yet, however, Government recognises the urgency of the issues for authorities and developers.

Our plan has policies / SPDs dealing with the nutrients issue – do we need to do anything?

Yes. The plans/policies/SPDs and advice you have in place may need updating for several reasons:

- NE has revised its advice and methods of calculating impacts – do your policies and advice reflect these changes?

- Your present policy etc. may only be for dealing with excess nitrates – excess phosphates are also affecting many more places now, so you need to check if phosphates also need mitigating in the catchment you are already dealing with.

Our plan is about to be submitted or is at examination. We have a strategy/policy for nitrate mitigation in a particular catchment, but the recent NE advice introduced the problem of ‘phosphates’ into the same catchment. How will Inspectors view this?

Knowing what we do about how they work, it is likely that Inspectors will assess the nitrates issue via the Habitats Regulations Assessment (HRA). This will inform them if there is a mitigation requirement and whether a suitable mitigation response is in place before deciding whether this is acceptable in plan-making/soundness terms.

One issue that many LPAs are facing currently is the basis on which their mitigation policy/approach has been put together – Natural England has changed its advice recently. Another issue is that many mitigation strategies currently only deal with the nitrates issue. Phosphates are now an additional issue for many catchment areas.

A nitrates-only mitigation strategy for a catchment area that now has issues with nitrates and phosphates is unlikely to be sound. The scale of the issue will have to be weighed-up, the required mitigation measures identified, and an assessment of how long it will take to get them in place will need to be made. This is additional work that is likely to have to be done to convince the Inspector that a sound policy/strategy is in place. Plans may be delayed while this is worked out.

Authorities are lobbying Government on this, and PAS is talking to Government about how we can all work together to reduce the impacts.

 Does this affect our 5-year housing land supply (5YHLS)?

Yes, potentially. Any allocated site that has not yet been permissioned will potentially no longer be part of the 5YHLS because it will be ‘undeliverable’ until a suitable mitigation strategy is in place. This needs to be assessed – how many sites in your land supply are affected (i.e., in the catchment area)? How much of a buffer do you have? How quickly do you think mitigation can be put in place for those sites/land making up your 5YHLS?

Won’t this put pressure on other parts of our area to accept development in unsuitable/unsustainable/unallocated locations?

Yes, potentially. The inability to grant permissions in one part of the local authority area (especially on allocated sites) may make development come forward in less desirable areas, with developers arguing that the LPA cannot demonstrate a 5YHLS. The pressure to deliver housing, and the potential effect on the 5YHLS, may open up other parts of your area to speculative development.

Local authorities are lobbying Government on this and PAS is talking to Government about how we can all work together to reduce the impacts.

What about Performance?

This may affect your ability to meet Development Management (see next set of FAQs) process performance targets and the Housing Delivery Test. Local authorities are lobbying Government on this and PAS is talking to Government about how we can all work together to reduce the impacts. Watch this space.

Development Management

What types of development are affected?

Natural England’s advice applies to all development, but the focus is on development that results in additional overnight stays. Development that will result in additional overnight accommodation may bring new people into the catchment and generate additional wastewater.


Nutrient Neutrality applies to applications where there is a net increase in the number of dwellings. This may include single dwellings. It does not generally apply to householder applications such as extensions if the LPA uses an average occupancy figure in the NE nutrient budget calculation i.e., 2.4 people per dwelling. This approach is in line with NE guidance and the calculators. If the LPA decides to use an alternative approach to occupancy (e.g., on a per bedroom basis rather than average per dwelling) then it may need to consider householder applications such as extensions. It may also need to consider replacement dwellings if there is a change in property size.

Consideration may also need to be given to specific cases, such as changes to Houses of Multiple Occupancy which lead to an increased number of occupants. 


In general, commercial development, schools and retail can be exempted. This is because it is generally accepted that people tend to work and live in the same catchment, therefore additional wastewater is accounted for by the new housing.

In exceptional circumstances i.e., very significant commercial developments that attract people as visitors or for employment from outside the catchment area, nutrient neutrality may be needed. Where an authority is unsure, they should discuss with Natural England at the earliest opportunity to clarify whether a Habitats Regulations Assessment is required.


Tourist accommodation is within the scope of the nutrient neutrality advice. Tourism infrastructure for day visitors should be included if there is clear evidence that people are travelling from outside the catchment.

Campsites operating on a 28-day basis should be considered if the site has wastewater infrastructure. Any impact would need to be pro-rata to only 1 month, and the assessment would need to make a judgement as to whether the proposal would result in a likely significant effect.

Agricultural and industrial applications

Agricultural infrastructure and industrial applications should be considered on a case-by-case basis due to the variation in nature and scale. Nutrient neutrality applies to agricultural developments that lead to an intensification of use and therefore increased nutrient loads.

How should we deal with planning applications?

LPAs will need to develop a strategy to deal with planning applications. It is likely that LPAs will place a temporary pause on determination of planning applications while they consider the full implications of Natural England’s advice.

There is no one-size-fits-all approach so you will need to consider the extent to which your area is affected. Some authorities may decide on a blanket pause on issuing decisions whereas others with small areas affected may decide to pause determination of planning applications within the catchment only. Be aware that where developments are close to the boundary of a catchment, you will need to consider whether the wastewater drains into or outside of the catchment.

Note that householder applications are generally excluded, based on using an average occupancy figure of 2.4 for new dwellings.

What about applications already in the system?

LPAs should contact applicants to advise them that there will be a delay in determining planning applications to enable proposals to be screened in or out of the need for nutrient neutrality. Based on the experience of other authorities, we recommend the following steps:

- Getting a communication out straight away is vital. Communities and developers will want to know how you are planning to deal with the issue.

- Set out your initial approach (this could be something as simple as; understanding the issue, understanding which developments will be affected, quantifying the impact, working with all stakeholders and developers on mitigation strategies, working with stakeholders on longer term solutions).

- Talk to applicants to understand the exact nature/position of their site and their thoughts on mitigation options – many will have already got experts involved and be formulating ideas.

- Negotiate extensions of time (9 month minimum) or a Planning Performance Agreement (PPA).

- Discuss whether withdrawal is an option until things are more certain.

- Avoid refusing permission (although some clients may want you to so they can appeal).

- Discuss the issue with agents / developers at forums that you have established.  If you don’t have appropriate forums in place already this could be a good reason to establish one.

How do we ascertain whether a development is affected by the requirement to consider nutrient neutrality?

LPAs should first consider whether an application is for a development type covered by nutrient neutrality – see above. Where a screened-in development type may give rise to additional nutrients within an affected catchment, either because the development is within an affected catchment boundary, or it drains into an affected catchment, it will be necessary to undertake a habitats regulations assessment (HRA), as per Natural England’s advice.

The LPA, as a Competent Authority, should only grant permission if it is certain that the development will not adversely affect the habitats site. If adverse effects cannot be ruled out, then it is unlikely that permission can be granted unless suitable mitigation is available.

Some authorities that are already dealing with nutrient issues have established processes and procedures to enable efficient screening of developments. We will share these here soon.

How should we deal with future planning applications?

There is no one size fits all and you will need to consider the extent to which your area is affected by nutrients following initial information gathering. How you deal with future applications will be determined by your understanding of the local context.

Once you have decided what is in and out of scope, you will need to set out clearly what your approach is to development affected by nutrient neutrality i.e., locations and types of development. This will help to reduce the number of applications received that will require mitigation.

Customers need to understand what is happening and how it may affect their development. What are their options? What do you want customers to do? Many councils have changed their local validation procedures to put them in control of what applications enter the system. Review your local validation list to ensure the applicant is clear about the information that will be required to enable the LPA to consider a planning application in an area affected by nutrients.

For applications received, we recommend that you negotiate extensions of time (9 month minimum) or a PPA, and/or discuss whether withdrawal is an option until things are more certain. Refusal of an application will need careful consideration.

You should also consider setting up a developer forum – if you don’t have one the this is a very good reason to do so.

There is a range of measures you can take to manage applications more efficiently, for example, you might add the catchment information to your GIS system. We will share examples of best practice from other LPAs here.

When can we start deciding applications for development in the catchment area?

To be acceptable, a proposal for development needs to:

- Be supported by a Habitats Regulations Assessment (HRA) which demonstrates that the development will avoid or have a neutral effect on nutrient pollution OR

- Be supported by an HRA and an appropriate mitigation strategy if the development will have an adverse effect on a protected site

There are temporary or short-term solutions available designed to buy time to establish long-term mitigation solutions. A lot will depend on availability of land, finance and whether you are dealing with nitrogen or phosphorus.

Places already dealing with this issue advise that long-term mitigation options are not a quick fix – you should plan on the basis that it may be between 1 and 2 years at the earliest before acceptable mitigation options in place.

What if we just continue issuing planning permissions ‘while all of this is being sorted out’?

Permissions issued in those catchments identified by Natural England (NE) are at risk of being found unlawful, resulting in the Local Authority facing legal challenges and reputational damage. NE has evidence that designated sites within the catchments identified are adversely affected by nutrients and that only a development that can prove it will reduce or have a neutral impact on nutrient levels in the catchment will be lawful. Unless appropriate assessment has been carried out and a mitigation strategy in place, then making a lawful decision on a planning application will not be possible. 

What about conditions and reserved matters? Q3.8 What about conditions and reserved matters?

Natural England advises that the requirement to consider nutrient impacts applies to planning applications at the reserved matters approval stage of the planning application process, and to applications for grants of prior approval and/or certificates of lawfulness for a proposed use or operation.

Opinion is divided among Barristers - some are of the opinion conditions and/or reserved matters are not ‘caught’ – that the principle of development has been established and that these can be discharged/decided. Other Barristers disagree and cite case law that demonstrates that this issue can be revisited at any point in the application process. Most councils’ ‘in-house’ legal teams are likely to suggest that conditions/reserved matters are included and that these should be treated as applications and unless mitigation is in place, then they should not be decided.

Some councils are taking a risk-based approach and are discharging conditions and taking extra care should the conditions include items relating to drainage. Other councils are simply not processing them. It’s a choice, a risk-based choice. 

At this early stage a cautionary approach is understandable, but whatever approach is taken it would help everyone if the approach was consistent across the catchment where two or more authorities are involved.

It seems likely that further legal advice will emerge in the coming weeks and months which will hopefully provide more clarity.

Natural England's advice & nutrient neutrality methodology

What does the updated NE advice cover?

The updated advice provided by Natural England (NE) includes tools for assessing the impacts of overnight stays, including a set of nutrient neutrality principles, guidance, and nutrient budget calculators for each catchment. Decisions trees for screening in and out of the Habitats Regulations have also been provided.

NE recognises there is a gap in the information provided for mitigation measures. There is currently no handy tool for mitigation because each catchment is very different, and mitigation needs to be bespoke. NE is progressing further information on different mitigation interventions and guidance on where the interventions may be best suited, and this will be released to LPAs in the Summer.

Applicants for other developments e.g., agriculture and industry, will need to provide bespoke nutrient calculations, given that these proposals are very site specific.

How has this changed from the previous advice changed?

The previous advice has been updated and the methodology is now based on updated water/agricultural land use/urban run-off figures, agricultural land use modelling, more recent agricultural census, and data changes. There are also changes to how Wastewater Treatment Works (without permit) figures are agreed. Other changes are about making the approach more specific, so not using an average for whole catchment but more site specific.

For existing catchments, NE expect LPAs to transition to new advice, but this does not need to be immediately.

Are the catchment boundaries provided by Natural England definitive?

In general, a buffer area does not need to be applied for a river catchment. If a development is located outside of the sensitive river catchment and does not drain (run-off or wastewater) via surface water or groundwater pathways into the sensitive catchment, then the application can be screened out.

How do the catchment boundaries provided by Natural England deal with the scenario where a development inside the catchment drains to a Wastewater Treatment Works (WwTW) discharging out-with the catchment, and vice versa?

If a development is located within an affected catchment but is served by a wastewater treatment works that discharges outside of the sensitive catchment, the wastewater element of the proposed development can be excluded. The drainage of surface water will still need to be considered though.

If a development is located outside an affected catchment but is served by a wastewater treatment works that discharges within the catchment, a habitats regulations assessment will be required. This also applies to surface water drainage.

The nutrient calculators include ‘look up’ tables which list all sensitive Wastewater Treatment Works for each catchment.

What can be done to help LPAs and developers quickly and easily identify whether a proposed development is likely to require further assessment due to the location of Wastewater Treatment Works (WwTW) discharges?

Local Planning Authorities have reported concerns about the additional time and effort required to obtain and analyse data regarding the locations of WwTW and the discharges relative to proposed developments and catchment boundaries etc. 

Furthermore, some LPAs have reported errors in the nutrient calculators provided by Natural England, which includes ‘look up’ tables listing WwTW in each catchment. These are being checked. In the meantime, if you identify any issues with your calculators, please raise it with Natural England.

In addition, Government, statutory agencies, and water companies will work together to make the information more readily available to LPAs and developers to determine more easily whether a project is affected or not.

Can existing catchments have a period of transition?

For existing catchments (where nutrient neutrality already applied), NE is advising that it is perfectly reasonable to have a period of transition, where planning applications are well progressed in the system.

Can new catchments phase-in nutrient neutrality?

No. For new catchments, a transition period is not possible. There is a much higher risk for developments that have not previously applied a nutrient neutrality methodology. 

Where can we find the data and science behind the Natural England announcement?

A summary report for each catchment has been issued to all affected local planning authorities. The site condition assessments are available here -

Does nutrient neutrality apply to both surface and wastewater?

Nutrient neutrality covers both foul and surface water discharge to the mains network, as well as off-mains drainage to package treatment plants and septic tanks (which can drain to ground or surface water / streams / rivers etc

Wider issues