RP29: Self-supporting covers for slurry and anaerobic digestate stores

This item is part of Capital Grants 2025. You must read the Capital Grants 2025 guidance 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 to understand the rules and how to apply.

How much you’ll be paid

£29.50 per square metre (m2).

How this item benefits the environment

It provides a self-supporting cover to an existing circular slurry or on-farm anaerobic digestate store. This stops rainwater from entering slurry or anaerobic digestate stores, so reducing the volume of slurry you need 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:

• for roofing an existing above ground circular store
• in areas targeted for the reduction of water and air pollution from agriculture

Catchment Sensitive Farming provides advice where there are water or air quality, or flood risk issues linked to farming.

You must get advice from the Environment Agency to check what’s required as new and significantly altered stores may have to meet the silage, slurry and agricultural fuel oil (SSAFO) regulations 2010.

You cannot use this item:

• for floating covers
• to cover any structure other than a slurry or on-farm anaerobic digestate store

Get permission to use this item

You’ll need to get relevant advice, consents or permits from the Environment Agency 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 self-supporting cover with a minimum design life of 20 years (with maintenance)
• install a rainproof and self-supporting cover, supported above the slurry or anaerobic digestate store and fastened by tensioners to the side of the tank
• make sure the tank can support the cover
• install the cover only when the store is empty
• direct the rainwater away from the slurry or anaerobic digestate store into a clean water drain or rainwater harvesting system
• display appropriate warning signs to warn of the dangers of confined spaces and fragile covers
• meet the requirements of the SSAFO regulations 2010 and Nitrate Vulnerable Zone (NVZ) requirements (if applicable)

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 photographs of the completed work and provide with your claim.

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
• any consents or permissions connected with the work, including evidence of SSAFO compliance (where relevant)
• any consents or permissions from the 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

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 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.

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.

Consult an engineer before using this item

Before starting the works, a structural or civil engineer will need to check the existing store can support a cover. You’ll need to contact a specialist supplier or tank manufacturer.

Separating water and slurry

Read about separating water and slurry at the Rivers Trust.