Washington's King County has set a deadline in late September for receiving bids to construct the first of three tunnel sections that will form the 13 mi (21 km) conveyance system for the future Bright-water Wastewater Treatment Plant (WWTP). The tunnel will have separate pipelines conducting influent to the facility and conveying effluent to a marine outfall that will extend into Puget Sound. To avoid untoward effects when discharging into that environmentally fragile water body and to ensure that the treated wastewater can be reused, the WWTP will employ a unique combination of advanced secondary treatment processes and enhanced primary treatment methods capable of producing a highly polished effluent even during periods of extremely heavy flows.
展开▼