RP30: Floating covers for slurry and anaerobic digestate stores and lagoons
Source: gov.uk (2025-07-03)

Find out about eligibility and requirements for the floating covers for slurry stores and lagoons item.

This item is part of Capital Grants 2025. You must read the Capital Grants 2025 guidance (https://www.gov.uk/government/publications/capital-grants-2025) to understand the rules and how to apply. If you’re applying for this item as part of a Countryside Stewardship Higher Tier (CSHT) application, you must read the CSHT applicant’s guide (https://www.gov.uk/government/publications/countryside-stewardship-higher-tier-csht) to understand the rules and how to apply.

How much you’ll be paid

£2.75 per square metre (m2).

How this item benefits the environment

A floating cover for slurry and on-farm anaerobic digestate stores and lagoons helps reduce the volume of slurry you need to store and spread. It also improves air quality by reducing ammonia emissions.

This item can help you protect, recover and improve biodiversity on your land.

Where you can use this item

You can only use this item with support from Catchment Sensitive Farming (https://www.gov.uk/guidance/catchment-sensitive-farming-reduce-agricultural-water-pollution):
- in areas targeted for the reduction of water and air pollution from agriculture
- to cover existing slurry or on-farm anaerobic digestate stores or lagoons
Before you start any work, you must get advice from the Environment Agency to check what’s required as new and significantly altered stores will have to meet the silage, slurry and agricultural fuel oil (SSAFO) regulations 2010 (https://www.gov.uk/guidance/storing-silage-slurry-and-agricultural-fuel-oil).

Get permission to use this item

You’ll need to get relevant advice, consents or permits from the Environment Agency (https://www.gov.uk/guidance/check-if-you-need-an-environmental-permit) before starting any work.

You must also contact your local planning authority to check if planning permission is needed.

What you must do to use this item

You must:
- install a floating cover with a minimum design life of 5 years (with maintenance)
- install a rainproof floating cover on a slurry or anaerobic digestate store or tank
- make sure the tanks or the lagoon’s earth banks can support the cover and fastening implements
- install the cover when the store is empty
- direct the rainwater away from the cover into a clean water drain or rainwater harvesting system
- display warning signs to warn of the dangers of confined spaces and fragile covers
- secure the cover to avoid wind damage and prevent rainwater running off and mixing with slurry
- place the cover on floats only if needed
- meet the requirements of the SSAFO regulations 2010 (https://www.gov.uk/guidance/storing-silage-slurry-and-agricultural-fuel-oil) and, if applicable, Nitrate Vulnerable Zone (NVZ) (https://www.gov.uk/nitrate-vulnerable-zones) requirements
- regularly remove rainwater from the cover to ensure it does not mix with the slurry
- ensure the cover is not impeded and it can rise uniformly
Evidence you must keep

You must keep written support from your Catchment Sensitive Farming adviser and provide this with your application.

You must also keep and provide with your claim:
- photographs of the completed work
- any consents or permissions connected with the work
- any consents or permissions from the local planning authority, or evidence that you do not need consent or permission from your local planning authority
If you do not need consent or permission from your local planning authority, you must provide evidence to show this. This can be a:
- letter from the authority confirming you do not need permission
- note of a telephone conversation with a local authority representative, with the name, date, and time of the call
- link to online guidance or printout of guidance text which shows you do not need permission
You must also keep and provide on request:
- receipted invoices or bank statements where a receipted invoice is unavailable
- photographs of the site before works start
Read the record keeping and site visit requirements in the Agreement holder’s guide: Capital Grants, Higher Tier capital grants and Protection and Infrastructure grants (https://www.gov.uk/government/publications/agreement-holders-guide-capital-grants-higher-tier-capital-grants-and-protection-and-infrastructure-grants-2025) for more information.

If you’re applying for this item as part of a Countryside Stewardship Higher Tier (CSHT) application, read the record keeping and site visit requirements in the CSHT agreement holder’s guide (https://www.gov.uk/government/publications/countryside-stewardship-higher-tier-csht).

Advice to help you use this item

The following advice may help you to use this item, but you do not have to follow it to get paid. It’s not part of this item’s requirements.

British Standards

Check to make sure the work meets relevant British Standards (https://www.bsigroup.com/en-GB/products-and-services/standards/).

Regulations for slurry stores

The slurry stores should meet the silage, slurry and agricultural fuel oil (SSAFO) regulations 2010 (https://www.gov.uk/guidance/storing-silage-slurry-and-agricultural-fuel-oil) regulations which cover the design, construction and maintenance of the stores.

Maintaining the drains

Drains should take rainwater from the cover and transport it to clean water ditches and drains. The drains need to prevent the rainwater from mixing with slurry or digestate. You may need a pump to help transport the water.

Separating water and slurry

Read about separating water and slurry at the Rivers Trust (https://s3.eu-west-2.amazonaws.com/assets.theriverstrust.org/Legacy-uploads/Organic-by-products-6.0-1.pdf).