Nitrate Vulnerable Zones Action Programme review: consultation

8. Storage requirements for organic manures

8.1 Storage requirements for slurry, silage, and other manures

The NVZ Action Programme contains specific rules relating to the storage of different manure types. These rules relate to:

• minimum storage capacity required for livestock slurries
• minimum storage capacity required for poultry manure
• storage options for poultry manure and other solid manures e.g. FYM
• minimum standards of construction for permanent storage facilities
• the maintenance of storage facilities for livestock manure and silage effluent
• the location of field sites for temporary storage of solid manures.

The above storage requirements are to prevent manure effluent runoff into surface waters or seepage into groundwater, which can lead to nitrogen pollution.

The capacity of storage facilities for livestock manure and silage effluent on a farm must be sufficient to store all livestock manure and silage effluent which is likely to require to be stored on the farm for such period as may be required to meet Action Programme measures for closed periods, and appropriate weather/ ground conditions for application to avoid pollution of the water environment.

The Water Environment (Controlled Activities) (Scotland) Amendment Regulations 2021 updated and consolidated existing controls for the storage of slurry and silage aligning requirements both within and outwith NVZs. These Regulations also introduced controls over the storage of materials associated with energy production from anaerobic digestion to protect the water environment, which also apply within NVZs.

Given these measures introduced by the Water Environment (Controlled Activities) (Scotland) Amendment Regulations 2021 updated current best practice, we do not propose further changes to the storage requirement for slurry, silage or materials associated with energy production from anaerobic digestion. The Water Environment (Controlled Activities) (Scotland) Regulations 2011 diffuse pollution mitigation measures will continue when it is replaced by the Environmental Authorisation (Scotland) Regulations 2018 from 1 November 2025.

Question 6

Do you agree with our review of storage requirements for slurry, silage, poultry manure and farmyard manure and our proposal that we do not change them at the current time? (Yes/No)

Where appropriate, please provide scientific research and evidence taking account of Scotland’s agricultural, soil and climatic conditions to support your view. (Text box)

8.2 Infield temporary storage of solid manures

The current requirement, in the Action Programme, for solid farmyard manure stored in field heaps is, that it must not be stored:

• in any field heap for more than 12 consecutive months;
• on the site of any previous field heap unless at least 24 months have passed since the site was last cleared.
• within 10 metres of any body of surface water;
• within 50 metres of any well, borehole or similar work sunk into underground strata for the purpose of providing a water supply;
• on any area of land that—

(i) slopes down toward a body of surface water; and

(ii) has a slope of 12 degrees or more;

• in any area identified on the risk assessment map as being of high risk to the water environment; or
• in any other location where there is a significant risk of nitrogen from the field heap entering a body of surface water.”.

The Scottish Government considered whether the risk from field heaps is sufficiently

mitigated to further measures such as the size and covering of field heaps.

Previous studies^[4] ADAS undertook on behalf of the UK administrations concluded that no benefit would be gained by amending the current legislative measures. Based on these findings we propose no changes to the requirements.

Question 7

Do you agree with our review of infield temporary storage of solid manure requirements and our proposal that we do not change them at the current time? (Yes/No)

Where appropriate, please provide scientific research and evidence taking account of Scotland’s agricultural, soil and climatic conditions to support your view. (Text box)