The phased introduction of the new soiled water rules increases a notch this month as no soiled water can be spread on farmland for the full month of December.

Last year, the rule was no soiled water to be applied between 10 and 31 December but the closed period is commencing on 1 December in 2024.

The exception to this is dairy farmers with a liquid/winter milk contract as they can apply soiled water up to 10 December as per last year.

However, by 1 December 2025 these farmers with liquid/winter milk contracts will have to comply with the extended 31 days closed period like all other farmers.

The Nitrates Action Programme states that it is only those with a liquid/winter milk contract that the delayed rule change will apply to.

So farmers that calve cows in the autumn and milk through the winter without a contract from a processor will have to adhere to the extended closed period for soiled water this winter.

In addition to this, all farms must have four weeks storage for soiled water in place by now, the exception to this are the aforementioned winter/milk producers who must have three weeks of storage in place by now.

Where slurry and soiled water are mixing together, the Department of Agriculture classifies this as slurry, not soiled water.

This means that a much longer closed period and a much more storage is required is required for this manure over just soiled water.

Soiled water production on dairy farms is estimated at 30l per cow per day although a new interim report on soiled water suggests that the figure, when rainfall runoff is included is 42l/cow/week.