When the California Regional Water Quality Control Board issued new waste discharge requirements in June 2002, California’s Nevada County Sanitary District 1 saw that a major upgrade of the existing lagoon system of Lake of the Pines Wastewater Treatment Plant (WWTP) would be required. Lake of the Pines is a planned residential community nestled in the foothills of the Sierra Nevada, about 50 miles northeast of Sacramento, Calif. The site offers the amenities of a country club, a championship 18-hole golf course and driving range, Junior Olympic pool, tennis courts, a clubhouse, slip boat marina, ponds and parks, all built around a 230-acre man-made lake. The county conservatively estimates that in the next 25 years, about 1,500 additional units will be needed.
The district appointed Kennedy/Jenks Consultants to identify, evaluate and select the most favorable wastewater treatment and disposal option to address not only the immediate permit requirements for higher effluent quality but also provide for the long-term needs of the community. The ENVIROQUIP MBR technology was selected because of its capability of meeting new effluent quality using existing plant footprint, its modular processes and layout to accommodate future expansion with ease of expandability and its competitive capital and operating costs.
The plant consists of anaerobic, anoxic and aerobic (pre-aeration and MBR) zones. Currently the system is designed for BOD reduction, nitrogen removal, phosphorous removal and solids separation.
To handle biosolids, an ENVIROQUIP PAD-K membrane system was added as a solution to produce sludge that meets class B requirements. The PAD-K system aerobically stabilizes the sludge and utilizes submerged membranes to thicken to 3% solids, minimizing the costs of transportation and operation of solid waste management.
The Lake of the Pines facility is one more ENVIROQUIP MBR wastewater treatment plant operating in California. The plant became operational in February 2008 and it has proven to be a perfect solution. The plant discharges year-round into Magnolia Creek.