Improving South Taranaki’s supply of quality drinking water

Mt Taranaki might be beautiful to look at, but delivering projects around it can be challenging. Our innovative approach to design challenges at Kapuni water treatment plant meant cost and time savings for the client, South Taranaki District Council.

South Taranaki District Council wanted a new membrane filtration plant to improve the quality of local residents’ drinking water. CH2M Beca, as engineering consultant for the concept, preliminary and detailed design, delivered this – and more.

The Council enjoyed a saving in operational costs by approximately $66,000 per year. This was achieved by reduced pumping costs, delivering chemicals in their most economical form, and recovering energy in the groundwater supply using a heat pump to provide a low-grade heating supply that cut chemical heating costs by around 75%. Plus, by optimising the design of the treated water tanks, proposed chlorine contact tanks were removed – resulting in large capital cost reductions.

The stream water quality around Mt Taranaki is known to be highly changeable, so we used a S::CAN instrument to allow dosing control around feed-forward coagulant.

The design is also future-proofed. It includes provision for the future installation of a wastewater recovery system and allows for a future 50% capacity expansion.

Thanks to careful programme management, the Council’s plant was operational 12 months ahead of schedule, and 20% under the initial cost estimate.