This upgrade involved CH2M Beca assisting the Council to double its water supply capacity and improve the treated water quality and Drinking Water Standards compliance.
Waikato District Council appointed CH2M Beca to upgrade its existing facility, doubling its production capacity to 3,600 m3/d and improve treated water quality to meet the requirements of Drinking Water Standards for New Zealand (DWSNZ) 2005.
CH2M Beca carried out the preliminary design, detailed design, contract specification, construction monitoring and commissioning for this upgrade.
Water is sourced from the Waikato River. To address the risks with the use of this raw water source, an advanced treatment process was implemented. The process included dual media GAC/sand filters to address taste and odour and natural organics issues and UV disinfection to address potential protozoa and microbiological risks in the source. Flat bottom upflow clarifiers were utilised prior to GAC/sand filtration.
In order to reduce the plant wastewater production without compromising the quality of the treated water, CH2M Beca designers included an innovative reuse of ‘filter-to-waste’ as backwash water, reducing wastewater volumes and operational costs and negligible capital cost. A new sludge setting pond was also constructed.
The project was delivered on time, to budget and quality standards, and meets the DWSNZ (2005). The upgraded water treatment produced its first water in May 2006. The treatment process selection and design was sound, met current best industry practice, and has proven to be a robust and reliable plant.