Silo and slurry storage systems

Schedules 1 and 2 of the SSAFO regulations external link, list the requirements that silos and slurry storage systems must meet. The schedule details the specific standards in relation to proximity to watercourses, permeability of floors and walls, ability to collect and contain effluent/slurry, storage capacity and durability of structures.

The requirements of Schedule 1 and Schedule 2 regulations apply to all silage clamps or pits and all slurry storage systems, that have been constructed, substantially re-constructed or substantially enlarged, since 1 September 1991.

Structures that were in use prior to 1 September 1991 and have not since been substantially reconstructed or enlarged are exempt from Schedule 1 and 2.

SEPA requires written notification at least 28 days in advance of bringing a new, substantially enlarged, or substantially re-constructed silo or silage effluent tank and/or slurry storage system into use. Although not a requirement of the regulations, it may be beneficial to consult with SEPA before any works begin to ensure that the planned structure is compliant.

Making and storage of silage

The regulations require that where silage is made or stored, the person who has ‘control or custody’ of the silage,or of any crop which is being made into silage, must ensure the following:

  • silage is kept in a silo that meets the requirements set out in Schedule 1 of the regulations or
  • silage is made or stored, in a structure that is “exempt” from Schedule 1 of the regulations or
  • silage is made in the form of bales which are wrapped and sealed within impermeable membranes (or enclosed in impermeable bags) and are stored at least 10 metres from any inland or coastal waters

Where silage is made in bulk bags, the requirements of Schedule 1 do not apply providing that the bags are kept sealed and are made of 1,000 gauge polyethylene, or equivalent. The bulk bags should be stored on a firm level surface and incorporate a facility to enable the safe removal of effluent when present. The bulk bags must not be stored or opened within 10 metres of any inland or coastal waters.

The making of silage in a free standing field heap is prohibited in all cases. Earth bank silos can be used providing that all the effluent is contained and collected, the base is impermeable and the walls lined with an impermeable membrane.  

Slurry storage

Anyone having custody or control of slurry is required, by regulations, to store it in a slurry storage system which meet the requirements of Schedule 2, ensuring either that the regulations are satisfied, or that there is an exemption for the structure.

For full details of Schedule 2 please see SSAFO regulations external link.

The regulations do not apply to slurry which is stored temporarily in a tanker, with a capacity of 18,000 litres or less, used for transporting slurry on roads or around a farm.