The council is responsible for 14 reticulated wastewater systems that service 55% of properties within the district. Reticulated community wastewater schemes have been provided where:
- Unsanitary conditions were created through high groundwater conditions and/or urban growth; or
- Sale of Crown operations to Council required that a reticulated scheme be provided for, e.g. Arthurs Pass and Lake Coleridge
The wastewater schemes have a replacement value of approximately $193M (excluding land value). Overall there are 39 pump stations and eight wastewater treatment and disposal plants. Total length of the reticulation is 250km, varying in diameter from DN50 to DN600.
Council also operates two septage pits - Ardlui Road and Bleakhouse Road. These take septic tank (household and small business) wastewater.
Further information about the districts wastewater schemes is available in the 5Waters Activity Management Plans.
Eastern Selwyn Sewerage Scheme
The Eastern Selwyn Sewerage Scheme serves the townships of Rolleston, Lincoln, Prebbleton, Springston, and West Melton.
Providing adequate wastewater treatment and disposal services has been the main restriction in enabling development in the growth areas. Rapid growth was predicted to continue in some of these Eastern Selwyn townships. Therefore, the Pines I WWTP was designed, with construction starting in 2012, as a modular plant so that additional treatment works can be added in stages to service future demand with an ultimate capacity (permitted by resource consent) of 22,000 PE, with disposal to an 80 ha irrigation area.
Further additions are planned between 2015 and 2017 Pines III upgrades will commence which includes a bioreactor, UV lamps, four blowers, and the addition of another clarifier and irrigation pump. The cost of these improvements is $29.7 million and they will be funded largely from development contributions.