Water. Desalination + reuse
Issue link: https://fhpublishing.uberflip.com/i/1019735
Hyperion plans With its hyper-industrial aesthetic characterised by rows of giant bulging domes, vast settlement tanks and miles of snaking pipework, Hyperion Water Reclamation Plant (HWRP) in Los Angeles has become a darkly atmospheric location for TV programmes and films including Battle for the Planet of the Apes and The Terminator. 18 On Site September 2018 Water.desalination+reuse • Install advanced treatment to supply LAX Airport by 2021 • Construct a 70mgd membrane bioreactor facility by 2026 • Recycle 100 per cent of Hyperion's water by 2027 One of the oldest and largest wastewater treatment facilities in the world, Hyperion Water Reclamation Plant in Los Angeles, has a fascinating history with current plans to trial a membrane bioreactor and advanced water treatment processes. With a hyper-industrial aesthetic characterised by rows of giant bulging domes, vast settlement tanks and miles of snaking pipework, Hyperion Water Reclamation Plant (HWRP) in Los Angeles has become a darkly atmospheric location for TV programmes and films including Battle for the Planet of the Apes and The Terminator. The plant would have looked very different back in 1894, when its first basic incarnation was constructed on a 200-acre oceanfront plot to discharge wastewater into Santa Monica Bay. As the urban population grew, widespread objection to the presence of raw sewage in recreational waters prompted the construction of a simple screening treatment facility, in 1925, at the current Hyperion site, next to Dockweiler State Beach. This was upgraded in 1950 to include a full secondary treatment plant with biosolids processing to produce heat- dried fertilizer. However, dramatic population growth and a resulting surge in sewage forced it to scale back treatment, the fertilizer programme was suspended in 1957 and digested sludge was discharged directly into the Bay. Public outcry over the severe impacts to marine life drew the attention of the US Environmental Protection Agency (EPA) and the city was asked to sign a consent decree to rebuild and reinstate a full secondary treatment system designed to meet contemporary needs. This system was completed in 1987 and subsequent improvements today enable it to handle 265 million gallons of wastewater per day (mgd), roughly equivalent to 400 Olympic- sized swimming pools. Five-stage process Wastewater treatment at Hyperion today is a five- stage process that involves: pre-treatment, primary and secondary treatment, digestion and solids handling. Nasir Emami, environmental engineer for HWRP told Water. desalination + reuse: "Pre-treatment is a screening process designed to remove abrasive materials, like sand and grit, to protect downstream treatment. The mind boggles and the range of strange objects we have had to remove, from bowling balls to motorcycles." Gravity transfers the resulting sewage into the primary treatment system where roughly three quarters of all solid matter is removed through settlement. Giant underground tanks slow the flow of water down to two-to- three feet per minute and hold effluent for an average of two hours. Heavy solids sink to the bottom and are removed, oil and grease floats to the top where it is skimmed off. The resulting 'primary effluent' is sent through an intermediate pumping station and into secondary treatment where soluble and fine particulate organic matter is eaten by microorganisms. Downstream of this process, huge secondary clarification basins allow the remaining biosolids to settle. "Water is now considered compliant with EPA water quality standards and discharged into Santa Monica Bay via a 12-foot diameter pipe, located 190 feet below the surface and five miles out to sea," says Emami. Meanwhile, biosolids removed during primary and secondary treatment are pumped into