36 | Waikato District Council: Raglan Waterwater Treatment Plant T T Hugh de Lacy State-of-the-art scheme for Raglan Installation of the system began in January last year, and was completed in July this year. Above, Craig Hobbs, Waikato District Council chief executive, left, and Watercare chief executive Jamie Sinclair celebrate the occasion. REGIONAL DEVELOPMENT State-of-the-art technology supplied and installed in the Waikato town of Raglan, under a project managed by the Timaru-based wastewater treatment specialist Apex Water, has attracted a buzz of interest both locally and overseas, says Watercare Services project manager Peter Crabb. The Waikato District Council’s $30 million upgrade of the Raglan/Whaingaroa wastewater treatment plant is part of a wider plan to upgrade the district’s water services. The new wastewater treatment plant has a capacity of up to 6000 cubic metres per day, improving the quality of treated wastewater and enabling growth. “Apex installed a Membrane Bioreactor (MBR) treatment plant, which is a system known for its compactness, resilience, scalability and, above all, treatment quality,” Peter says. “It’s a key to creating sustainable practices and elevating treatment standards to minimise the impact on the environment. The MBR system takes wastewater through four stages of treatment, beginning with screening to filter out debris. “It then introduces biological treatment using a membrane aerated biofilm reactor (MABR) that uses airflow through the fibres suspended in the wastewater to subject it to both nitrification and denitrification. “After aeration, it enters the heart of the treatment process, with the MBR’s semi-permeable membrane filtering treated water from the sludge. “Finally, it’s given ultraviolet treatment that ensures the discharged water meets public health and environmental standards – all without the use of chemicals and without generating harmful by-products.” Peter adds that the installation of the MBR/ MABR technology in the Raglan/Whaingaroa wastewater scheme was “a significant milestone for environmental engineering in New Zealand, and it has attracted considerable comment and interest from overseas”. Installation of the system began in January last year, and was completed in July this year, with Apex Water being supported by groups of subcontractors that included the East Tamaki branch of the nationwide Kinetic Electrical Group, which handled the electrical work. The inlet works were delivered by Aqceptance, a German-based supplier of filtration, thickening, and screening technology, as well as water-protection systems, while Dupont supplied the Memcor MBR and the Oxymem MABR membranes. ControlWeb handled the automation, Civil and Build the earthworks and Riley Geotech Consultants the geotechnical advice. Main contractor Apex was launched as a water and wastewater consultancy in South Canterbury in 2009 by Matt Savage and Steve Kroening, initially focusing on food-and- beverage treatment installations, but expanding to have branches across both islands. The new Raglan wastewater system utilises the existing oxidation ponds as a buffer against storm events, allowing excess flow to be retained and then returned to the MBR process as soon as capacity becomes available. The ponds themselves offer a further and basic level of treatment, introducing sunlight, oxygen and naturally occurring organisms to the process. Water services for the town of Raglan are owned by the Waikato District Council and operated by Watercare Services. Partnered with Watercare, the Waikato District Council is planning and executing water infrastructure improvements across the region, and the Raglan/Whaingaroa upgrade is seen as pivotal both to meeting regulatory requirements and to sustaining population growth. Improvements to the drinking-water supply began in May 2023 with water-main, sewer and reservoir works. The residents of Raglan first campaigned for a (Raglan County) Council-owned water and wastewater system in 1938, but the council found borrowing costs to progress initially. That cycle was repeated in 1949, and it wasn’t until the 1960s that full services were introduced. “The Raglan/Whaingaroa wastewater treatment facility is a ground-breaking, scalable design that will provide the Raglan area with infrastructure critical to its growth, and contribute to overall water quality, local ecosystems and aquatic life,” Peter says.
RkJQdWJsaXNoZXIy NDc2Mzg=