Processing Magazine

Santa Cruz desalination plant environmental report published

May 21, 2013
Santa Cruz
 The report stated that with preventive measures incorporated into the design of the facility, its impact on the environment can be mitigated.

A long-awaited environmental impact report for a proposed seawater desalination plant at Santa Cruz, Calif., was released on Monday. The report stated that with preventive measures incorporated into the design of the facility, its impact on the environment can be mitigated.

The report also noted that a seawater desalination plant is the only possible option to supply Santa Cruz and Soquel Creek Water District with the fresh water communities need. One of the main purposes of the report was to examine alternative solutions to the local water supply problems but, after looking into eight different alternatives, the authors of the report concluded that building a desalination plant was the only way to ensure water supply to meet the needs of the local community.

Environmental analysis is required under the California Environmental Quality Act, to examine the potential impact of the facility on marine life and ocean water quality, among other issues. By incorporating certain features in the design of the facility the environmental impact would be significantly mitigated, said Melanie Schumacher, public outreach coordinator for the desal project.

Following release, the report will be open for public review over a period of 90 days. Similar projects are typically open for comment for 60 days only, but the comment period has been extended because of the length of the document and because of the upcoming vacation period. According to Gary Patton, a lawyer for the Community Water Coalition, it is an inquiry that should interest local people with technical knowledge and provoke them to look into it and ask questions and comment on anything they find wrong.

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Under the proposed plans, the facility will have the capacity to convert seawater into 2.5 million gallons of drinking water on a daily basis. To produce such an amount of drinking water, the process would take no less than 5 million gallons of seawater, the Santa Cruz Sentinel reported. It is planned that the desalination plant will be used at full capacity only when the city is going through periods of water shortage, whereas every day it would be functioning at about 50 percent of its capacity to replace groundwater supplied by aquifers that need to be out of operation for a certain period.

When highly concentrated salt extracted during desalination of seawater gets mixed with treated wastewater, it matches the salinity level of the ocean and it is then discharged back to Monterey Bay. The pipe through which the water is returned into the ocean will be outfitted with valves to ensure even distribution of the water and avoid brine plumes. The facility also features a special intake system that is designed to cause minimal damage to marine life.

Plans for the desalination plant state that the facility will be carbon-neutral thanks to installing energy recovery devices and buying energy offsets available from other facilities or organizations, the Santa Cruz Sentinel said.