Inyo County, California
Owens Lake is a dry lake bed located on the eastern side of the Sierra Nevada’s in Inyo County, California. It is about 5 miles south of a sleepy little town called Lone Pine. Unlike most dry lake beds that have been dried for thousands of years, Owens Lake held a significant amount of water until around 1913 when much of the Lake was diverted into the Los Angeles Aqueduct, causing the lake to dry by 1926. In 2013 it was considered the largest single source of dust pollution.
The Los Angeles Department of Water and Power (LADWP) awarded the contract for construction of Phase 9/10 of Owen’s Lake Dust Mitigation effort to OHL USA. The phase 9/10 of the Owens Lake project was designed to mitigate dust emissions on an additional 3.62 square miles of Owens Lake playa. But the completion of the project, the City of Los Angeles will have mitigated dust emissions from over 48 square miles of Owens Lake playa and will have reduced PM10 dust emissions from the lakebed by 99 percent. This effort by LADWP was completed in December 2017. Upon completion of the Phase 9/10, the City’s overall investment in the Owens Lake Dust Mitigation program has reached nearly $2 billion.
Stronghold Engineering was awarded the installation of 16.7 miles of Direct Burial of 5kV medium voltage cable and 15 sites included 7 Mechanical Pump Stations, 7 Lateral Valve Stations, and 1 Sand Filtering Station. Owens Lake’s ponds, lateral shallow flood, and managed vegetation require water for dust mitigation in compliance with environmental mitigation agreements. The Lake’s water use fluctuates throughout the day due to automated schedules that run over 150 shallow flood laterals and over 50 managed vegetation blocks. There are also numerous ponds filled by large submains throughout the lake. Water supplied for these different dust mitigation measures is suppled from the Los Angeles Aqueduct and the Lower Owens River Pump Station (LORPS) through a mainline pipe that transects Owens Lake. Project line developed control strategies for the implementation of a new Lake Flow Stabilization and Pressure Control tool. The strategies were implemented on Allen Bradley ControlLogix PLC’s communicating via Controlnet. Project Line’s scope included developing bench and on-site test procedures, and assisting with operator training.