"One of a kind" - unique treatment of grinder pump effluent

The Maketu community in Bay of Plenty required a modern and cost effective sewerage scheme to be built in a tight timeframe. A consent was obtained for a grinder pump system feeding into a local treatment plant and subsequent sub-surface drip disposal system. This scheme is unusual as only grinder pump effluent supplies the treatment plant and therefore there is minimal stormwater dilution of the plant influent. The paper describes the challenges faced by the technical team in setting appropriate performance criteria for the plant and disposal field. The advantages and disadvantages of using of the new FIDIC Gold Book for the design, build, operate contract are discussed as well as the use of collaborative contract procurement techniques to provide a robust and cost effective outcome for the community. The paper also describes the implementation of a number of initiatives to minimise capital and operating costs, minimise environmental effects whilst maintaining a robust solution for a community with widely fluctuating population.