City of Santa Barbara Subsurface Desalination Intake Feasibility Study

City of Santa Barbara, 
California

City of Santa Barbara Subsurface Desalination Intake Feasibility Study

Santa Barbara Beach

Carollo performed a feasibility analysis of subsurface intake (SSI) technologies for the City of Santa Barbara as a means to replace their existing screened open ocean desalination plant intake. Alternatives included SSIs based on relevant precedent installations and the current state of the technology. Carollo's work included a review of available literature to compare of potentially feasible alternatives, including vertical wells; lateral beach wells (onshore infiltration galleries); radial collector wells (Ranney wells); slant wells; subsurface infiltration galleries; and horizontal collector wells (Neodren). The analysis considered physical description, yield, water quality, regulatory requirements, construction impacts, reliability, and maintenance requirements.

The analysis also involved an evaluation of subsurface properties at each site to determine beach and shore area geologic and hydrogeologic properties, as well as  hydrogeologic modeling to determine individual facility yield, spacing, percentage of ocean water captured, groundwater and sensitive habitat impacts, and the potential to capture or mobilize groundwater contamination. In addition, hydrodynamic models provided a basis to analyze tsunami hazards and the potential for sediment transport.

Consistent for what would be required for new and expanded facilities, Carollo's analysis included initial screening to determine technical feasibility prior to the consideration of CEQA level economic, environmental, and social factors.
The project used a technical advisory process to provide an independent, third-party review at key intervals throughout the project.

Results of the study presented the maximum yield technically feasible for SSI alternatives, and will provide a basis for future studies, such as an update to Santa Barbara's Long Term Water Supply Plan.