Policy paper

Nutrient pollution: reducing the impact on protected sites

Updated 28 June 2023

Executive summary

Nutrient pollution is an urgent problem for our freshwater habitats and rivers, many of which are internationally important for wildlife. We must tackle this pollution to help meet our legal commitments to restore species abundance.

The need to address pollution on these sites is impacting permissions for development and slowing down housing delivery across 74 local planning authorities. We must address this to support sustainable development and achieving the government’s ambition of building 300,000 new homes each year by the mid-2020s.

The government is taking a range of steps to reduce pollution at source to protect these important wildlife sites and developing schemes to allow sustainable development to continue. Steps being taken include:

  1. Speeding up the process for developers to acquire mitigation through a national £30 million nutrient mitigation scheme.

  2. Significantly reducing pollution and the cost of mitigation by requiring water companies to upgrade wastewater treatment works in the Levelling Up and Regeneration Bill.

  3. Providing clarity for developers and local planning authorities with a package of tools and guidance, including the Wetland Mitigation Framework.

  4. Restoring our protected sites and tackling pollution at source with clear legally binding targets on water quality and protected site strategies.

Our protected sites and nutrient pollution

As set out in our Environmental Improvement Plan, our protected sites are important as they help reverse the decline of England’s nature and wildlife.

Our protected sites represent some of the nation’s most precious and sensitive habitats, providing wintering and breeding habitats for wetland birds and supporting rare species. They provide many important services to society including:

  • flood control
  • carbon capture
  • climate change adaptation
  • access to nature
  • benefits to public health and wellbeing

One of the main causes of decline in our protected sites is the damage caused by nutrient pollution in water courses. The sources of excess nutrients are site specific but mainly come from wastewater treatment works and agricultural pollution.

Increased levels of nutrients (especially nitrates and phosphates) damage water dependent sites, reducing the oxygen carrying capacity of the water and speeding up the growth of certain plants. This disrupts natural processes and harms the associated plants and wildlife. In technical terms it can put sites in ‘unfavourable condition’.

Nutrient pollution and new development

Many of our protected sites are designated and protected under the Conservation of Habitats and Species Regulations 2017 (the ‘Habitats Regulations’). They are termed ‘habitats sites’ in the National Planning Policy Framework.

Under the Habitats Regulations, ‘competent authorities’ such as local planning authorities and the Environment Agency must assess the environmental impact of projects and plans (such as planning applications or local plans) which affect habitats sites. Local planning authorities can only approve a project if they are sufficiently certain it will have no negative effect on the site’s condition.

As a result of these regulations and domestic and European case law, Natural England has issued advice for 31 habitats sites, spanning 27 catchments and a total of 74 local planning authorities (wholly or in part). This advice says that as these sites are in unfavourable condition due to excess nutrient pollution, projects and plans may only go ahead if the increase in wastewater that is produced by the assumed population increases, from developments, will not cause additional pollution.

One way developers can demonstrate that new projects will not cause additional pollution is through ‘nutrient neutrality’. This involves mitigating the ‘nutrient load’ generated by the population growth due to new housing developments.

The nutrient load is created by the additional wastewater produced by the assumed increase in inhabitants in an area. Developers now need to mitigate this load either onsite or elsewhere within the same catchment. This typically involves creating new wetlands to strip nutrients from water or creating buffer zones along rivers and other watercourses.

This approach means local planning authorities can grant planning permission for new residential development. We recognise that achieving this requirement under the Habitat Regulations may impose additional costs and delays on development.

The government is clear that delivering nutrient neutrality can only be an interim solution. Therefore, we have taken significant action to tackle pollution at source and restore our protected sites. We are also providing greater funding, certainty and support to enable developers to meet mitigation requirements in the short term.

Supporting nutrient neutrality

We have developed, implemented and continue to improve a package of support to ensure that developers and local planning authorities can achieve nutrient neutrality as quickly as possible. This has benefited from extensive engagement with local authorities, developers and conservationists. There are 3 pillars to nutrient neutrality.

Pillar 1: accelerating the supply of mitigation

Developers told us that they needed access to a greater supply of mitigation sources as quickly as possible.

Nutrient mitigation scheme

Natural England has quickly established a nutrient mitigation scheme. This scheme is supported by up to £30 million of funding from Defra and the Department for Levelling Up, Housing and Communities (DLUHC).

Selling ‘nutrient credits’ to housebuilders will then recover this funding. This will allow developers to meet their nutrient mitigation obligations and enable local planning authorities to grant planning permission. The scheme will help:

  • thousands of new homes to be built
  • create new wetland and woodland habitat where nutrient neutrality guidance is in place

These mitigation measures will be designed in a way that:

  • promotes nature recovery
  • improves access to greenspace
  • maximises other benefits such as biodiversity

Since July 2022, Natural England has been working closely to design and develop the scheme with government departments and bodies across Defra, DLUHC and local planning authorities.

The first mitigation projects are now underway in the Tees catchment area, with Natural England opening the first round of applications to developers on 31 March 2023. Feasibility studies are in progress in further catchments to determine the scheme’s next mitigation sites. The government is keen to see other catchment partners, such as environmental non-governmental organisations, getting involved in the designing and delivering future mitigation measures. Natural England is also inviting landowners to offer their land as potential sites for nutrient mitigation.

Local and private mitigation schemes

Alongside the nutrient mitigation scheme, developers can also mitigate their nutrient load through:

  • private nutrient credit trading schemes
  • local planning authority-led mitigation schemes
  • onsite mitigation solutions built into the design of housing developments

The government welcomes locally and privately operated schemes, and does not expect the nutrient mitigation scheme to be required in all areas. There are already good examples of such schemes in place in Somerset and the Solent.

To support this further, in the 2023 spring budget the government committed to provide funding this year for high quality, local mitigation schemes. A call for evidence from local planning authorities about the best way to fund these schemes will be published in spring 2023. Where high quality proposals are identified, the government will provide funding to support these mitigation projects to be created or scaled-up faster than usual.

Pillar 2: reducing pollution and the mitigation burden on new housing

By tackling wastewater pollution at source, we can reduce pressures on protected sites up front and reduce mitigation burdens on new housing developments.

Over the last 2 decades, the government has ensured that significant investment is targeted at improving wastewater treatment works and reducing their impact on the environment. For example, from 2020 to 2025 water companies will be investing £2.5 billion in measures that tackle nutrient pollution. This is in addition to improvements made in previous 5-year investment periods. Combined, these measures will produce an 83% reduction in the total load of phosphorus to rivers from wastewater treatment works compared to 1995.

The latest water quality monitoring data shows that we still need to go even further to reduce nutrient pollution from wastewater treatment works if we are to improve water quality. That is why we have introduced legally binding targets through the Environment Act 2021 to cut wastewater pollution by 80% by 2038.

In areas where protected sites are particularly affected by nutrient pollution, we are taking additional steps to address this pollution. Through the Levelling Up and Regeneration Bill, we have introduced a new duty on water companies in these areas to upgrade their wastewater treatment works. They will be required to achieve the highest technological levels for nutrient removal by 1 April 2030. For wastewater treatment works across all affected catchments there will be an estimated reduction of:

  • 69% in total phosphorus loads
  • 57% in total nitrogen loads

In addition, the upgrades will lower the mitigation cost to developers (depending on the catchment) by an estimated:

  • 37% to 95% for phosphate
  • 46% to 64% for nitrate

This cost reduction will be within 3 months of the bill gaining Royal Assent.[footnote 1]

Wherever possible, we want to see nature-based solutions forming part of these upgrades. For example, water companies can use wetlands and reedbeds in combination with conventional techniques such as adding metal salts to wastewater – to remove more nutrients from wastewater.

Where possible, and where it provides good value for public money, the government will also work with water companies to see where these upgrades could be sped up and created sooner.

Pillar 3: providing certainty

Developers and local authorities can find carrying out nutrient neutrality to be time-consuming and reliant on detailed expertise. The highly technical nature of nutrient neutrality can also create uncertainty around developer investments. We are addressing this through catchment specific nutrient calculators which allow developers to calculate exactly the amount of mitigation required, tailored to specific local needs.

We have also:

  1. Published a tool for assisting in the design of wetlands for nutrient mitigation.
  2. Published guidance for mitigation providers on how environmental payments from biodiversity net gain and nutrient mitigation can be combined.
  3. Provided advice about nutrient neutrality and support in assessing the suitability of mitigation projects, through increased capacity in Natural England.

The Planning Advisory Service has hired dedicated nutrients advisors who will work with local planning authorities to provide advice and share best practice.

Natural England is developing a framework for assessing the effectiveness of different types of mitigation and an associated reference tool. This will be published by the end of May 2023. They will also provide best practice guidance on using different constructed and nature-based solutions to mitigate nutrient pollution. This will be supported by new guidance from:

  • the Environment Agency on wetland permitting
  • DLUHC to clarify the planning practice guidance in response to feedback from developers and local planning authorities

You can read guidance on when nutrient mitigation proposals need environmental permissions, such as permits or licences. This explains how to get advice from the Environment Agency and Natural England, and how to apply.

Action to restore our protected sites to favourable condition

Nutrient neutrality can only be an interim solution while we speed up action to tackle nutrient pollution at source and improve the condition of our protected sites.

Ambitious long-term targets

The 25 Year Environment Plan, published in 2018, commits us to restoring 75% of our one million hectares of terrestrial and freshwater protected sites to a favourable condition by 2042. It also commits us to returning at least three-quarters of our waters to as close to their natural state as soon as is practicable. We have also set interim targets to have up to date condition assessment on all Sites of Special Scientific Interest by 31 January 2028, and 50% of all Sites of Special Scientific Interest to have actions on track to achieve favourable condition.

To achieve this, since 2018 we have taken a number of steps.

Environmentally sustainable farming

To promote environmentally sustainable farming we have:

  • driven environmentally sustainable farming by doubling funding available for the Catchment Sensitive Farming programme to £30 million in each of the next 3 years in England
  • opened the first year of new farming funding through the Sustainable Farming Incentive
  • launched the slurry infrastructure grant scheme to give farmers access to loans of up to £250,000 to upgrade their slurry storage capacity as part of a £13 million investment package

Storm overflows discharge reduction plan

We have published our storm overflows discharge reduction plan. This requires water companies to deliver their largest ever environmental infrastructure investment. This is made up of £56 billion of capital investment over 25 years to tackle storm sewage discharges.

We have also expanded the storm overflows monitoring programme from only 5% of storm overflows monitored in 2016 to nearly 90% in 2021.

Planning requirements

We have improved planning requirements to support water availability, enabling an additional £469 million of water company investment to develop new strategic water resources

It is now also a requirement that water companies produce high quality water resources management plans and drought plans.

Ofwat policy

We have published our strategic policy statement for Ofwat, which sets clear long-term priorities for the water industry and the economic regulator.

Environment Act 2021

Through our Environment Act 2021, we set legally binding targets to directly address nutrient pollution in the water environment from agriculture and wastewater by:

  • reducing nitrogen, phosphorus and sediment pollution from agriculture into the water environment by at least 40% by 2038 (against a 2018 baseline)
  • reducing phosphorus loadings from treated wastewater by 80% by 2038 (against a 2020 baseline)

Environment Improvement Plan

Our revised Environmental Improvement Plan 2023, published on 31 January 2023, builds on the 25 Year Environment Plan vision by setting out how we will deliver our environmental goals. This includes delivery plans for long-term Environment Act 2021 targets, matched with stretching interim targets for 2028 to measure progress. Part of these are specific interim targets for reducing nutrient pollution from agriculture in catchments containing protected sites in unfavourable condition. These go beyond the national interim target for nutrient pollution from agriculture.

Pollution from wastewater

We are working with the water industry and regulators to ensure that considerable investment is directed at reducing nutrient pollution from wastewater.

Drainage and Wastewater Management Plans

Through the Environment Act 2021, drainage and wastewater management plans (DWMPs) will become statutory. Government will implement the relevant provisions during the next DWMP cycle (2023 to 2028). These plans set out how they will manage and develop their drainage and sewerage system over a minimum 25-year planning horizon.

The government’s strategic priorities for Ofwat

For the forthcoming price review period, Defra have published the strategic policy statement to Ofwat. This makes it clear that Ofwat and water companies should consider nutrient pollution alongside their environmental duties (which includes the Habitat Regulations). It also says that water companies should be challenged to prioritise improvements to protected sites and to work with wider stakeholders to support efforts to tackle nutrient pollution.

Proactive investment

We will require water companies to upgrade 160 of their wastewater treatment works to meet the strictest phosphorus limits by 2028. A further 400 will need to be upgraded by 2038, to reduce harmful nutrient pollution from treated wastewater.

We will reduce sewage pollution by holding water companies to account for delivering the targets set out in the storm overflows discharge reduction plan.

Enhanced regulation and enforcement

We will ensure water companies are delivering on our targets and commitments through:

  • enhanced transparency and monitoring mechanisms in the Environment Act
  • targeted enforcement from regulators
  • increasing the maximum fines

We will direct water company fines relating to environmental breaches to improving the water environment.

Pollution from agriculture

We are supporting farmers to prevent and reduce nutrient pollution.

Slurry infrastructure grant

On 6 December 2022 we opened the first round of the slurry infrastructure grant. The scheme helps livestock farmers to upgrade their slurry storage to make best use of their organic nutrients and cover stores to minimise ammonia loss. In round 1 projects will be prioritised in areas where urgent action is needed to reduce nutrient pollution from agriculture.

Farming Equipment and Technology Fund

We are offering grants for best available techniques to help farmers increase their productivity whilst reducing pollution. Farmers can use the scheme to help invest in nutrient analysis equipment, slurry separators and low-emission spreaders. The first round funded over 750 dribble bar and trailing shoe applicators for slurry, worth £5.3 million, which can reduce air pollution during spreading by 30 to 60% and prevent nutrient leaching to waterways.

Environmental land management schemes

Our environmental land management schemes are rewarding farmers for using sustainable practices that:

  • reduce nutrient pollution
  • improve the resilience of their business to climate change
  • make more space for nature in the farmed landscape

This includes investment in cover crops, buffer strips and river restoration projects.

Catchment Sensitive Farming

The Catchment Sensitive Farming partnership provides specialist, free, direct environmental advice to farmers in England. Since 2006 it has been proven to improve water quality by up to 5% in areas it has been focussed. We have increased its funding and it now covers all of England.

Farm inspectors

We have provided the Environment Agency with additional funding to increase the number of farm inspectors by at least 50 and better target their activity using remote sensing. This resource will target the highest risk sites and increase the annual number of farm inspections from 400 to at least 4,000 a year.

Protected site strategies

Protected site strategies will address the greatest challenges facing protected sites through the development of a tailored package of measures to tackle on and offsite pressures, including nutrient pollution. In doing so, we will create opportunities for nature recovery, support sustainable development and put sites on a pathway to recovery.

In spring 2022, Natural England launched 5 pilots, which will provide the evidence base for protected site strategies rollout over the next 3 years and inform subsequent guidance. The pilots are testing the full potential of protected site strategies at different geographical scales and for a range of on and offsite issues including air quality, water quality, nutrient pollution and overgrazing, proposing actions to restore nature on affected sites.

  1. Figures from internal Defra analysis. Estimated nutrient load reductions are totals across all affected catchments and will vary between individual catchments. They carry a 20% uncertainty level.