30 | Council ensures safe drinking water The Kaiwara Water Scheme, south of Cheviot, involves 95km of reticulation, and 72 water connections spread across 188sqm. Hurunui District Council: Kaiwara Water Scheme T T Hugh de Lacy “New buildings, treatment equipment, pipework and electrical connections are all part of each scheme upgrade.” REGIONAL DEVELOPMENT The way the Hurunui District Council (HDC) achieved water-safety protozoa compliance has won it the prestigious Excellence Award from the Institute of Public Works Engineering Australasia. Hurunui, north of Christchurch, manages water schemes from 26 water sources across its 8641sqm, and it faced a severe test in bringing them up to scratch against new National Standards requiring all drinking-water supplies to have protozoa barriers. Planning at the HDC to meet the standards began in 2019 under the district’s 2018-2028 long-term plan. “We had to have regard for the Government’s proposal to transfer water assets and services out of council hands, but the council considered it vital for its communities to have access to safe water, irrespective of whether this transfer occurred,” HDC project manager Dan Langman says. The changes were unaffordable for smaller supply systems, and at the time the HDC had few protozoa barriers in place, none of them meeting the new standards. In 2015, the council consulted with the community and it was agreed to implement a district-wide equitable rating system for all drinking-water supplies. “This was an ambitious project requiring the upgrading of 16 water treatment plants,” Dan says. “Previously, the council had used external technical expertise, but this would have been too expensive for Hurunui, so if we were to master our water management we’d need the appropriate skillset in-house.” In a courageous step, given Canterbury’s sensitivity to water quality, the HDC chlorinated all its water supplies because of the recurring E. Coli transgression, typical of networks of their size. This 2017 action triggered the rapid decline of these counts to zero in 2019, and since then, there has not been a single confirmed result. The network recorded high protozoa transgression counts that year, but the HDC’s response saw them slashed to zero in 2019 – and there hasn’t been a single one confirmed since. Taking the experts’ skillset in-house required the establishment of a project-management office to oversee the design, construction and operation of the water-treatment plant upgrade, with resultant cost savings. This involved removing unreliable schemes, and merging two high-quality schemes to form the new Waikari Basin scheme, and the introduction of four new water sources, two of them to service the rapidly growing Amberley area. The Kaiwara Water Scheme, south of Cheviot, involves 95km of reticulation, and 72 water connections spread across 188sqm, which was upgraded in the later stages of the project. “All of our water-treatment plants are unmanned because of the geographic spread, and the Kaiwara scheme had to be updated to allow for automatic plant shut-down, to modify plant settings and configuration, and for restarting the plant remotely,” Dan says. “New buildings, treatment equipment, pipework and electrical connections are all part of each scheme upgrade. “The resilience of the scheme has been improved with triple communications in the form of a digital radio network, ethernet over radio and cellular communications.” The net result is the end of boil-water notices in the Hurunui. • STRUCTURAL STEEL FABRICATION • STAINLESS STEEL PIPE INFRASTRUCTURE • HEAVY TRANSPORT REPAIRS AND FABRICATION • FULLY CERTIFIED WELDING SPECIALISTS • SITE SAFE GOLD ACCREDITED Hurunui Engineering Ltd is proud to support Hurunui District Council with their water scheme development projects. CONTACT US! Phone: 03 314 9326 | Email: robbie@hurunuieng.co.nz HIRE, SALES AND SERVICE OF QUALITY POWER GENERATORS 0800 230 400 | www.qpower.co.nz Whether you need emergency generation for a short-term fault, a large industrial backup power system or a regular service plan undertaken by specialist QPower technicians, QPower has a solution for you. POWER
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