{"id":28336,"date":"2024-05-08T15:54:08","date_gmt":"2024-05-08T19:54:08","guid":{"rendered":"https:\/\/www.parsons.com\/?post_type=project&p=28336"},"modified":"2024-06-12T14:44:47","modified_gmt":"2024-06-12T18:44:47","slug":"joint-water-pollution-control-plant-sewer-tunnel-outfall-los-angeles-ca","status":"publish","type":"project","link":"https:\/\/www.parsons.com\/project\/joint-water-pollution-control-plant-sewer-tunnel-outfall-los-angeles-ca\/","title":{"rendered":"Joint Water Pollution Control Plant Sewer Tunnel Outfall \u2014 Los Angeles, CA"},"content":{"rendered":"\n

We are the lead designer for the Joint Water Pollution Control Plant (JWPCP) Sewer Tunnel Outfall Tunnel project.<\/strong> The Sanitation Districts of Los Angeles County<\/a> are 24 independent special districts serving the wastewater and solid waste management needs of approximately 5.6 million residents in Los Angeles County. Seventeen of the Sanitation Districts are signatories to a Joint Outfall Agreement providing a regional, interconnected system of wastewater management facilities known as the Joint Outfall System (JOS). <\/p>\n\n\n\n

Purpose Of The Joint Outfall System (JOS)<\/h3>\n\n\n\n

The JOS provides wastewater collection, treatment, reuse, and disposal for residential, commercial, and industrial users, and it includes seven treatment plants, the largest of which is the JWPCP, located in the City of Carson. Currently, secondary treated effluent from the JWPCP is conveyed through two 6-mile-long tunnels to a manifold structure located near White Point on the Palos Verdes Peninsula. Four sea-floor outfalls extend offshore from the manifold structure. The two main outfalls are 90 and 120 inches in diameter and extend approximately 1.5 miles offshore, discharging approximately 200 feet below sea level. <\/p>\n\n\n\n

Key Features Of The Joint Water Pollution Control Plant Sewer Tunnel Outfall<\/h3>\n\n\n\n

The new effluent outfall tunnel will be approximately 7 miles long, have an 18-foot internal diameter, and include 1,350 feet of 16-foot diameter steel liner at the Palos Verdes Fault crossings. The new tunnel will allow for inspection of the existing tunnels, provide redundancy for the effluent management system, ensure capacity for future growth, and convey peak storm flows. The upstream end of the project will include constructing a junction structure to connect the tunnel to an active 14-foot-diameter force main. The existing manifold structure at the downstream end of the project will be demolished, and a new manifold structure will be constructed. Since the existing tunnels and main outfalls are always required to be in service, a temporary bypass system will be constructed and operated during this project phase.<\/p>\n\n\n\n