The table below represents a short list of the options still under review. The discharge consent application will include a ‘preferred option’ from this list. As required by the Resource Management Act (RMA), the application will also need to outline why other options were discounted.
1 Tertiary membrane: Is a fine filter that removes solids and bugs;
2 Membrane Bioreactor (MBR): Is an advanced treatment process that removes nutrients, solids and bugs;
3 Existing treatment process: Oxidation ponds with aquamats that promote biological treatment of wastewater followed by U.V disinfection;
4 Winter flow: This period is when soils are saturated to a point where land irrigation is not possible, and increased flows to the WWTP occur (typically during rainfall events)
In day-to-day management, fully treated wastewater is released on an outgoing tide into Raglan Harbour.