Uisce Éireann has issued an appeal to the dairy industry to not dispose large quantities of milk into the wastewater network.
The utility, formerly known as Irish Water, said that the improper disposal of milk can have a serious impact on the environment and wastewater infrastructure.
Although not currently a significant problem nationally, Uisce Éireann said there has been some localised incidents, particularly in Co. Cork.
During spring of this year there was an issue in Aghabullogue where the wastewater treatment plant received “a shock loading of milk”.
This puts significant pressure on the wastewater treatment plant resulting in operational difficulties with the treatment process, the utility said.
There has been similar issues in Grenagh, Rylane, Kilbrittain and Dripsey, which have proven to be both challenging and costly.
Uisce Éireann
Large quantities of milk that go untreated can ultimately make its way into the receiving waters and can have a major impact on the local environment.
Milk has extremely high biological oxygen demand, 10 times higher than cattle slurry, and 400 times the level of domestic sewage.
The environmental impact of a litre of milk is equivalent to a full day’s wastewater from a family household.
Disposal of milk to sewers can create a shock load on treatment plants with consequent pollution effects.
“Last year we issued an appeal to all parties in the milk industry, and seen some improvement,” Paddy O’Dwyer, wastewater source control lead, said.
“However, we continue to see incidents occur where milks loads are being disposed into the wastewater network.
“It’s particularly common during the spring and summer months and it puts a significant strain on Uisce Éireann’s wastewater infrastructure.
“We are not talking about pouring a litre or two of milk from the fridge out, this is large quantities of milk that needs to be disposed of appropriately,” he added.
“We are asking everyone associated with the milk industry to be very conscious of the impact this can have on wastewater networks and treatment plants and would ask that they dispose of milk and other products correctly.
“Large quantities of milk should be disposed of either in slurry pits or to a licenced waste facility.
“We would encourage everyone involved in the industry to spread the word of the potential damage that pouring large volumes of milk down the drain can have,” O’Dwyer said.