Rules for storing slurry on farms
If you store slurry, you must follow certain regulations if your storage facilities were constructed or substantially altered after:
- 1 December 2003 in Northern Ireland
- 1 September 1991 in Scotland
In Northern Ireland, older storage facilities are normally exempt from the regulations. However, you may have to carry out improvement work if your environmental regulator considers that your facilities could cause pollution.
You may not be able to use the structure until all necessary works are completed.
In Scotland from 01 January 2022 slurry storage systems constructed prior to 1 September 1991 are no longer exempt from the regulations.
What you must do
Notify your environmental regulator in writing before you use new or substantially reconstructed or enlarged stores.
In Northern Ireland, the Northern Ireland Environment Agency (NIEA) requires at least 28 days' notice.
In Scotland, SEPA requires at least 30 days' notice.
Contact your environmental regulator
Site the slurry storage system at least 10m from any water including field drains or ditches into which slurry could enter if it were to escape.
You must construct new or substantially reconstructed or enlarged stores to last for at least 20 years with proper maintenance.
In Scotland you must not store slurry:
- within 10 metres of surface water or wetland
- within 50 metres of any spring or borehole.
Farming and Water Scotland: Slurry and manure
Capacity
When you add new storage or alter existing storage, you must normally provide storage capacity for:
- at least 26 weeks slurry production on farms with a pig or poultry enterprise, and 22 weeks for all other farms in Northern Ireland
- the total quantity of slurry likely to be produced in 26 weeks by housed pigs, or, 22 weeks by housed cattle in Scotland.
If you don't provide the required storage you must prepare a farm waste (manure) management plan.
DAERA: COGAP and farm waste management (Northern Ireland)
In Northern Ireland, the reception pits and associated channels can normally hold at least two days' slurry production, including rainfall draining to the pit.
In Scotland, the capacity of any facility used for the temporary storage of slurry before it is transferred to a slurry storage tank must be the equivalent of at least 1.5% of the minimum on farm storage capacity.
If you use a sluice gate to control the flow of slurry to a reception pit, you must ensure the pit can hold the maximum quantity of slurry that can be released when the sluice is opened.
Do not overfill your slurry store. Keep the top 0.3m for above ground slurry stores and 0.75m for slurry lagoons empty.
You must maintain slurry storage tanks, channels, pipes, valves, and reception pit to ensure they are free of any structural defects during their lifetime.
Design and construction –
The following requirements apply to slurry storage tanks built:
- In Northern Ireland, after the 1 December 2003
- In Scotland, all slurry tanks, including those built before 1 September 1991,
Make the base of slurry storage tanks and the base and walls of effluent tanks, channels, reception pits and pipes impermeable, you can buy commercially available treatments for this purpose.
Extend the base of the slurry store beyond the walls and perimeter drains, and provide an effluent tank where the walls of the slurry store are not impermeable.
Provide two valves in series on any drainage pipe from the slurry tank and lock them shut when they are not in use. Each valve must be able to stop the flow of the slurry.
Where a slurry storage system has walls made of earth, the system must not be filled to a level which allows less than 750 millimetres of freeboard, and in all other cases the slurry storage tank must not be filled to a level which allows less than 300 millimetres of freeboard. Freeboard, in this case, is the distance between the top of the tank and the surface of the slurry tank.
The following further requirements must be followed for slurry storage tanks built:
- after the 1 December 2003 in Northern Ireland
- and after the 1 September 1991 in Scotland.
Construct the base and walls of slurry tanks and any reception pits so that they can withstand the loadings specified in British Standard (BS) 5502: Part 50: 1993.
Protect the base and walls of slurry storage tanks, effluent tanks, channels, reception pits and pipes against corrosion, in accordance with (BS) 5502: Part 50: 1993.
In Scotland from 1 January 2022:
- any slurry storage system, constructed, or substantially reconstructed or enlarged, on or after 1 January 2022, which has walls made of earth, must be lined with an impermeable sheet material which, with proper maintenance, slurry cannot permeate for a period of at least 20 years,
- not be situated within 10 metres of any surface water or opening into a surface water drain which slurry could enter into if it were to escape.
In Scotland, a slurry bag may only be used to store slurry if:
- the bag is constructed of impermeable material of sufficient strength and structural integrity such that it is unlikely to burst or leak in its ordinary use, and
- it is situated in a bund which complies with the following requirements -
-
- the bund must be of at least equivalent capacity to the slurry bag,
- the bund must be lined with an impermeable sheet material which, with proper maintenance, slurry cannot permeate for a period of at least 20 years,
- the bund must have a means of removing rainwater, and
- other than as necessary to allow rainwater to be removed, the base and walls of the bund must not be penetrated by any valve, pipe or other opening.
Good practice
You can increase the available capacity of your slurry storage by preventing rainwater entering the system. You should:
- cover stores
- divert clean water from roofs or hard standing to discharge directly to surface water drains for treatment via sustainable drainage systems (SUDS).
Further information
The codes of good agricultural practice provide guidance on how to avoid polluting water with slurry.
In Northern Ireland, see section 2 of the DAERA code of good agricultural practice for water, air and soil.
DAERA: Code of good agricultural practice for the prevention of pollution of water, air and soil
NIEA: Silage, slurry and agricultural fuel oil information
In Scotland, see section 4 of the Prevention of Environmental Pollution from Agricultural Activity (PEPFAA) Code.
CIRIA: Farm waste storage - Guidelines for construction