Milking Centre Washwater Regulation

On January 1, 2011, the General Nutrient Management Regulation (O. Reg. 267/03) under the Nutrient Management Act, 2002 (NMA) will be amended and come into effect changing how milking centre washwater can be disposed. The intent of the regulation is to stop milking centre washwater from entering water sources by not allowing the washwater to be emptied directly into drainage ditches, streams, or field drainage tiles.

What this will mean to the dairy producer?

The first thing to know is that the part of the regulation that deals with milking centre washwater will come into effect on January 1, 2011.

How soon after January 1, 2011 you have to comply with this regulation depends on whether:

• you are currently required to have a nutrient management strategy by O. Reg. 267/03 and
• you make changes to your milkhouse or your milkhouse washwater treatment system.

If you currently are not required to have a nutrient management strategy, this new regulation will only apply if you:

• build or replace a milking parlour or milkroom, where the milkroom is defined as the room where the bulk tank is located
• expand an existing milking parlour or milkroom if the permit also includes an increase in the size of the bulk tank
• build a new, replace an existing, or undertake any other construction for which a building permit is required in relation to a sediment tank, treatment trench system or milking centre washwater storage facility.

If you currently are required to have a nutrient management strategy under O. Reg. 267/03 then there are two ways you can be phased-in to the new milking centre requirements. You will be phased in based on whichever event happens first:

• you apply for a building permit for any of the three situations outlined above or
• it is January 1, 2016.

If you are phased-in without any new construction and your existing sediment tank and treatment trench
system were constructed before April 6, 1998 then the existing system may be sufficient to satisfy the regulatory requirement if the following two conditions apply:

• the system treats the first rinse separately and
• there are no liquids escaping or seeping or improper discharge.

Once you are phased into this part of the Regulation then you will be required to store the washwater and either land apply it according to the Regulation or you must treat the washwater. The new standards for
treatment will permit any of the following:

• appropriate treatment approved under the Building Code
• appropriate treatment approved under the Ontario Water Resources Act (OWRA) or
• a mixed anaerobic digestion facility that is regulated under the NMA.

Milking centre washwater can be either stored in:

• A liquid manure storage or
• A solid manure storage meeting with a runoff management system, as long as the addition of the washwater does not result in a liquid mixture and the amount does not exceed 250 litres per day.

If you are an existing dairy producer, not required to prepare a nutrient management strategy under the regulation and do not apply for a building permit as outlined above, then you are not affected by the new regulation. However, you should always follow best management practices and dispose of your milking centre washwater safely.

This infosheet is intended for information purposes only and you should refer to Part VII.1 of the General Regulation (O.Reg. 267/03) under the Nutrient Management Act, 2002 for full detail on how you could meet the requirements to store or treat the washwater. This infosheet may be amended from time to time.

Learn More

Non-Agricultural Source Material (NASM) - information on new regulatory requirements.