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

Find out about eligibility and requirements for the self supporting covers for slurry stores item.

• From: Rural Payments Agency and Natural England
• Published: 2 April 2015
• Last updated: 3 February 2025 — See all updates

• Grant type: Capital item
• Land use: Air quality, Biodiversity, Uplands and Water quality
• Tiers or standalone items: Higher Tier, Mid Tier and Standalone capital items
• Funding (per unit per year): Up to £100

This item is part of Capital Grants. You must read the Capital items: guidance for applicants and agreement holders 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:

• any consents or permissions connected with the work
• 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 for more information.

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.

Published 2 April 2015

Last updated 3 February 2025 + show all updates

1. 3 February 2025

   General improvement for clarity.

2. 30 March 2021

   'Air quality' added to Land use.

3. 3 March 2021

   Updated wording in the following sections: Where to use this item, Where this item cannot be used, Where this item cannot be used, How this item will benefit the environment and Requirements.

4. 1 February 2021

   Update to title to include: and anaerobic digestate stores. Added in links to Capital Grants manual as this option is now available for Capital Grants

5. 29 March 2016

   Information updated for applications in 2016

6. 2 April 2015

   First published.