Rules for storing soiled water, effluents and silage bales

From 1 December 2025, all milk producers irrespective of their system of production (spring or winter) must have a minimum of 31 days soiled water storage on their farms.

This requirement is to coincide with the prohibited application of soiled water on lands from 1 December to 31 December.

This means the allowance for winter milk producers to have less than 31 days storage for soiled water during this period is no longer available.

Soiled water is defined under the Good Agricultural Practice for the Protection of Water regulations as water from concreted areas, hard standing areas, holding areas for livestock and other farmyard areas where such water is contaminated by contact with any of the following substances:

Soiled water or slurry

Under the regulations, soiled water does not include any liquid that has either:

Soiled water which is stored together with slurry, irrespective of the storage facility, is deemed to be slurry.

All efforts should be taken to minimise the volume of soiled water produced.

All clean water in the farmyard must be diverted to a clean water outfall and prevented from entering storage facilities.

This means that all roof gutters and downpipes must be in place and fully functional to prevent clean water mixing with yard pollutants.

The regulations also state that there shall be no direct runoff of soiled water from farm roadways to watercourses.

General storage

With regard to general storage for soiled water and effluent the Department conditionality handbook advises that “for soiled water storage facilities constructed before the 1 January 2015, the required storage capacity for soiled water should equal or exceed the capacity required to store all soiled water likely to arise on the holding during a period of 10 days, or for a period of 15 days in the case of soiled water storage facilities constructed after the 1 January 2015”.

How much soiled water does dairy produce?

There is no figure in the regulations for exactly how much soiled water is associated with each cow in a herd.

Teagasc recommendations are to allow for 30l/cow in the herd when calculating requirements with this figure irrespective of the size of parlour, number of runs per system or aspects such as if flush wash systems are used.

This quickly translates to 0.21m2/cow/week and as stated already every effort should be made to both minimise soiled water and slurry production.

Farmers investing in storage facilities should note that year one of a two-year study carried out in Teagasc Moorepark shows the volume of slurry produced by dairy cows could be underestimated by 20% with soiled water production underestimated by as much as 30%.

The Teagasc study noted “a second year of monitoring is required to provide a full understanding of overall volumes collected’’ and ‘’while this project will provide data to the Department of Agriculture to inform policy associated with the Nitrates action programme, any changes to current regulations will be dependent on the consideration of a range of associated issues by the Department, in addition to this data”.

Silage bales

Conditionality rules govern the manner in which silage bales and farmyard manure (FYM) can be stored. With regard to silage bales, they cannot be stacked more than two bales high or stored within 20m of a surface water/water abstraction point, unless there are storage facilities in place to collect effluent.

Supplementary feeding points for feeding livestock outdoors also cannot be situated within 20m of a watercourse or on bare rock.

In addition sacrifice paddocks or designated areas of the farm where livestock are kept to save other areas of the farm from damage are not allowed under conditionality.