Monterey Peninsula Water Supply Project EIR/EIS, Monterey, CA.


Sutro Science is playing a key role in this complex regional water resource supply project in Monterey County involving desalination, Aquifer Storage and Recovery, and recycled water for agricultural irrigation. The California American Water Company must replace existing Carmel River and groundwater water suppliesresources that have been constrained by legal decisions related to endangered species protection and basin overuse. 

A desalination plant utilizing a subsurface slant well seawater intake system installed along the coast and aquifer storage and recovery facilities are proposed to capture excess winter flows from the Carmel River for storage in the Seaside Aquifer, for use during summer months. 

Issue Areas and Involvement

The project has been subject to wide ranging and intersecting technical, legal, and political hurdles. Key issues include potential impacts related to the discharge of reverse osmosis return water (desalination brine) into Monterey Bay; adverse effects on the Salinas Valley Groundwater Basin associated with the operation of the proposed subsurface slant wells; and, impacts to the benthic marine life from brine discharges.

Sutro Science is providing technical leadership in support of NEPA and CEQA environmental review and planning efforts. With responsibility for evaluating all groundwater impacts relating to the Salinas Valley Groundwater Basin as well as oceanic water quality impacts relating to the discharge of desalination brine into the Monterey Bay National Marine Sanctuary, technical management requires understanding of stakeholder concerns, regulatory requirements, and unique technical issues. Successful outcomes involved considered coordination of engineering and scientific sub-consultants with expertise in marine resources, quantitative modeling of groundwater water quality and flow dynamics, hydrologists, coastal process engineers, and water quality specialists.



Project Services

Groundwater hydrology and water quality environmental impact assessment.

Ocean water quality impact assessments related to desalination discharges that may be combined with different streams of municipal wastewater. 

NEPA/CEQA Impact evaluation and strategy.

Project alternative development.

Environmental mitigation strategy and development.


Consultant Team: Sutro Science, ESA, Applied Marine Science, Philip Roberts (Georgia Tech), Trussell Technologies.

Project Partners: CPUC, MBNMS, MRWPCA, CalAm.

Regulatory Agencies: Regional Water Quality Control Board.