As South Coast Water District works toward constructing a seawater desalination plant at Doheny State Beach, the California Coastal Commission (CCC) voted to allow the agency to conduct geotechnical testing and monitoring at the beach.
Through a single vote on routine items during its meeting on Nov. 16, the California Coastal Commission voted to approve geotechnical testing and the installation of two monitoring wells at Doheny State Beach as the water district works to prepare a final site plan for its desalination project.
The monitoring wells will work to determine the best location for the plant’s slant wells that will draw in water from beneath the ocean floor, by evaluating the subsurface conditions.
SCWD Assistant General Manager Marc Serna noted that the coastal development permit approved last week is an “important component that will essentially provide the necessary geotechnical information for construction of our slant wells, which are very innovative and a unique approach of subsurface intake technology, that is very specific for our Doheny ocean desalination project.”
“Without this permit, we would not be able to proceed with the geotechnical borings, exploratory drilling that would allow us to better define where and how our slant wells will be constructed at the campground and ultimately to optimize the production of water for our plant,” Serna continued.
The project was approved on the condition that South Coast Water District obtain all necessary permits and approvals prior to the start of development.
According to the CCC’s staff report, the project will require approvals from the California Department of Parks and Recreation and the San Diego Regional Water Quality Control Board.
Another condition of approval requires the water district to monitor and limit noise generated by equipment and construction. To that end, the staff report notes that the water district will install barriers around project equipment to reduce noise levels.
Additionally, South Coast Water District is expected to develop a Spill Prevention and Response Plan and a Construction Best Management Practices to “avoid and reduce coastal resource impacts.”
The water district is also expected to retain a Cultural Resource Specialist and a Native American Monitor “representing the Juaneño Band of Mission Indians, Acjachemen Nation-Belardes, if requested by the Tribe.”
The Cultural Resource Specialist and Native American Monitor would oversee initial excavations and may “halt construction if previously unknown cultural resource sites or materials are encountered.”
Construction of the monitoring wells will also impact campsites at Doheny State Beach for two months, the staff report notes. To minimize public impact, State Parks and the water district have worked together to provide additional camping opportunities elsewhere during the closure.
State Parks also plans to conduct campground improvements and modifications during the plant’s construction, so the grounds are only closed once for both projects. The campground improvements will include electrical, water and sewer hook-ups to individual campsites, upgrades to restrooms and more.
Serna explained that the data obtained from the monitoring wells and exploratory drilling will help to inform SCWD’s future Design, Build, Operate team. The water district aims to award a contract for the Design, Build, Operate team by spring 2024.
The Design, Build, Operate team “will take that information and incorporate it into the actual designs of the slant well facilities,” Serna said. “That is part of the overall first phase of the design, which will get us to a 60% level design.”
“That will also identify a guaranteed maximum price for the project, also referred to as GMP,” Serna continued. “GMP will set a firm price for the construction of the project and the long-term operational cost of the Doheny project.”
Work to install the monitoring wells and conduct geotechnical testing is expected to begin in January. More information on the Doheny State Beach campground closures can be found at SCWD.org/dohenycampgroundupgrades.