11 Reservation Road*
Marina CA 93933-2099
Plant Operator: Joe Correa
*Located at Marina State Park at the edge of the Pacific Ocean:

11 Reservation Road
Marina, CA 93933-2099
Leo Laska, General Manager
Emmette Randle, Jr., President, MCWD Board of Directors
Evelina Adlawan, Technical Services Manager
Dave Foote, District Engineer
TEL: 831-384-6131
FAX: 831-384-2479
EMAIL: mcwd@mcwd.org
WEB PAGE: http://www.mcwd.org

Ionics, Inc.
65 Grove St.
Watertown MA 02172
TEL: 617-926-2500
FAX: 617-926-4304
EMAIL: CorpMark@postoffice.ionics.com
WEB PAGE: http://www.ionics.com
Contact Persons: T. G. Papastavros or P. A. Lynes

Schaaf & Wheeler Consulting Civil Engineers
445 Reservation Rd.
Marina CA 93533-3301
TEL: 831-883-2540
Contact Person: Katherine Oven, Senior Engineer

Seawater Intake Well

• Located west of the Marina State Beach parking lot
• Bottom elevation of about- 50 feet MSL (Mean Sea Level)
• 12'' diameter casing, 520 gpm discharge rate
• Seawater Total Dissolved Solids (TDS) = 22,000 mg/L

Pre-Treatment Filtration Anti-Scalant Addition & Cartridge Filtration

• "Threhold treatment" for scalants that can foul up the reverse osmosis membrane
• Represses both calcium cabornate and calcium sulfate crystal formation process
• Inhibits formation of other potential scalants such as oxides or hydroxides of iron, managanese and silica
• Removes turbidity, suspended solids and other materials to prevent scaling of fouling of membrane

Reverse Osmosis Desalination Process

• Pre-treated seawater is forced under pressure through a simipereable membrane for removal of chemical impurities and solids like salt
• Single pass system with profected recovery rate of 67%. Seawater is desalted in one pass of membrane disalination.
• Permeate (Product Water) water quality: Total Dissolved Solids = 280 mg/; ph = 5.7; hardness = 25mg/L; Alkalinity = 2mg/L (corrosive characteristics)

Post Treatment (Lime & Carbon Dioxide Addition; PostChlorination)

• To satbilize corrosive characteristics of premeate (Product Water) produced from the reverse osmosis process
• Addition of hydrated lime to increase calcium hardness and raise ph
• Addition of carbon dioxide to increase alkalinity (carvon dioxide converted to bicarbonate after hydrated lime addition)
• Water quality after post treatment: Total Dissolved Solids = 380mg/L; ph =8.5
• Chlorine is added in the final stage for disinfection

Injection Well

• For disposal of the defect brine, off-spec. water and seawater feed bypas
• Located in the west end of the existing wastewater reclamation plant
• 115'depth fiberglass reinforced plastic (FRP) casing and screen at approximateley 65' - 105'
• 16" Diameter casing

The Marina Coast Water District Laboratory performs extensive water quality monitoring in order to ensure Marina's safe drinking water supply. Title 22, Division 4, Chapter 15 of the California Code of Regulations stipulates that we monitor coliform bacteria on a weekly basis. One water sample from each of five Marina residences is collected and analyzed each Monday. A different set of five is analyzed each week in a month, so there are a total of 20 different individual residences from which water is collected for coliform analysis. Coliform bacteria is strictly monitored because it acts as an indicator of contamination and it can cause intestinal illnesses.

One coliform sample is analyzed weekly from the desalination plant as well. In addition, desalinated water is monitored for pH, turbidity, conductivity, and total dissolved solids daily. Cholride, sulfate, and selenium are analyzed on a weekly basis.

The regulations also require that we test for total trihalomethanes (TTHMs) in the distribution system ( we test 4 individual residences) quarterly. Our 4 wells and 2 reservoirs are tested annually for volatile organic compounds (VOCs), general minerals, and inorganic chemicals. Desalinated water is tested for these constituents quarterly because it is a new water source. If problem areas are found, they are tested more frequently.

In addition to the above analyses, the MCWD lab performs weekly monitoring of general physical parameters. Each week we test water from 5 residences, 4 wells, and both reservoirs for temperature, pH, turbidity, odor, color, conductivity, total dissolved solids, and sulfide. The wells are also tested for chloride. The purpose of this monitoring is to detect any abnormal concentrations that might indicate problems within the system. Weekly monitoring ensures that any problems will be detected and remedied quickly.