The treatment of process wastewater starts with our operations.
We make sure our cleaning processes are optimised and milk residue is minimised. This limits the amount of nitrogen, phosphorous and other organic components in the water.
We use a range of treatment processes to clarify and clean the wastewater before we irrigate onto our nutrient management farms or discharge it once treated, into the Waikato River (in accordance with our consent).
Currently, at Hautapu, we do this by utilising dissolved air flotation (DAF) plants. These plants clarify process wastewater by releasing dissolved air under pressure, which attaches to suspended fats and solids as it rises to the surface of the DAF tank, removing them from the process wastewater.
VIDEO: Watch the detailed process of how we treat process wastewater.
At the new facility process wastewater will flow through a tank, segregated into several sections, where microorganisms break down any organic matter (mainly milk residue) and reduce nitrogen (including nitrates) and phosphorous from the process wastewater.
The water then goes through a clarifying process where the microorganisms settle out and are returned to the treatment tanks, leaving clear treated process wastewater.
When soil conditions are suitable the treated process wastewater is irrigated onto our nutrient management farms.
When soil conditions don’t allow for irrigation, it goes through a final filtration and UV light step. UV lights work to kill any bacteria and phosphorous is reduced even further through filtration before discharging into the river as per our proposed resource consent.
Groundwater is located underground in layers of water-soaked rock or gravel, often referred to as the water table. It comes from different sources including rainfall, lakes, rivers, and streams.
Around a third of the water used in New Zealand comes from groundwater.
We’re committed to producing dairy nutrition in a way that cares for people, animals and our environment, and brings value to our communities.