Zone 7 Mocho Groundwater Demineralization Plant Project

Zone 7 Mocho Groundwater Demineralization Plant Project

The proposed project consists of construction and operation of a 7.7 mgd demineralization facility, which would be located adjacent to Arroyo Mocho off Stoneridge Drive and Santa Rita Road in the city of Pleasanton, California. The facility would treat potable water supplies from existing wells in the vicinity. Operation of the proposed facility would consist of demineralization or reverse osmosis treatment of source or raw water from the water wells. Reverse osmosis (RO) is a physical separation process, in which water is pressurized and passed through a semi-permeable membrane. Molecular constituents (i.e., calcium, magnesium, sodium, etc.) larger than the molecular pore size of the membrane do not pass through, and exit the membrane system as concentrate. Demineralized water molecules pass through the membrane and exit the system as permeate or product. Demineralization would occur through the use of an RO membrane-based treatment, producing permeate water and concentrate. Zone 7 would blend permeate with other groundwater (non-demineralized) and/or surface water before delivery to achieve a target total dissolved solids or hardness level. The concentrate solution resulting from the RO process would be discharged into San Francisco Bay via the Livermore Interceptor, which is located along the northern portion of the project site and/or via the Dublin San Ramon Services District (DSRSD) Export Pipeline.

Pleasanton

Alameda

California Department of Fish and Wildlife, Bay Delta Region 3 (CDFW), California Department of Health Care Services (DHCS), California Department of Parks and Recreation, California Department of Transportation, District 4 (DOT), California Highway Patrol, California Native American Heritage Commission (NAHC), California Regional Water Quality Control Board, San Francisco Bay Region 2 (RWQCB), Department of Toxic Substances Control, Department of Water Resources, Office of Historic Preservation, Resources Agency, State Water Resources Control Board, Division of Water Quality, State Water Resources Control Board, Division of Water Rights

Other (Groundwater demineralization facility, 7.7 mgd on ~ 1 acre site)

Groundwater demineralization facility

Aesthetics, Air Quality, Biological Resources, Cultural Resources, Cumulative Effects, Drainage/Absorption, Flood Plain/Flooding, Geology/Soils, Hazards & Hazardous Materials, Hydrology/Water Quality, Noise, Transportation, Vegetation, Wetland/Riparian