Barely two weeks after the City of Santa Cruz in California had accepted the preliminary design report by CDM Smith for its proposed 2.5 MGD (9,500 m³/d) seawater desalination plant, the city clerk’s office confirmed on 3 July 2012 that proponents of a charter amendment for a vote on the desalination project had collected enough signatures to place it on the November 2012 ballot.
The city council had previously adopted an ordinance in March 2012 that allowed residents to vote on the desalination project in June or November 2014, following completion of its environmental impact report (EIR).
The preliminary design report includes technical design considerations for three configurations located at three potential sites and will serve as a basis for evaluation of the proposed project in the EIR. It will be available soon on the project website.
From a screened open-water intake in Monterey Bay, the seawater will go through a process including cartridge filters and single-pass reverse-osmosis, with concentrate blended with treated effluent from the city’s wastewater plant. Provisions will be made for expansion to 4.5 MGD (17,000 m³/d) and a partial second-pass system to meet potential future water quality standards such as boron ≤0.5 mg/L
With construction costs estimated at US$ 61-66 million depending on site, the operating and maintenance costs are estimated to be US$ 3.12-4.34/year (Normal-Drought) or US$ 1.41-1.26/m³.