Monterey Peninsula Water Supply Project - Presentation to Monterey Co. Water Resources AgencyJune 25, 2012

Monterey Peninsula Water Supply Project

• Our application before the California Public Utilities

Commission is extensive. To signup for project updates or

view the application, visit our project website:

www.watersupplyproject.org

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Presentation Topics

• MPWSP Basics How GWR fits into our Project Where are we now

• Design of MPWSP Intake System to Minimize Intake of Inland Groundwater

• Desalinated Water Supply to SV User

• Seawater Intrusion Control Benefits

• Reclaimed Water Salinity Control

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MPWSP Basics

• Desalination and ASR facilities required to replace partial loss of supplies from Carmel River and Seaside Groundwater Basin.

• 5.4 MGD to 9.0 MGD (5,500 to 9,000 AFA) desalination plant, depending on implementation of MRWPCA’s GWR project.

• Desalination plant to be located near landfill entrance.

• 13.2 to 22 MGD slant intake system (6 to 8 Wells) on coastline

• Brine discharge to MRWPCA’s existing outfall

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Role of GWR

• Independent Project by MRWPCA

• Groundwater Replenishment (GWR) which takes secondary wastewater effluent and processes it through an Advanced Water Treatment facility is a great opportunity for the Peninsula by:

Lower overall Carbon Footprint Reduce Loadings to Monterey Bay Creates vast underground storage reservoir

• CAW’s desal plant will be sized nearly in half if GWR can be implemented.

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Where are we now?

• Submitted Application to CPUC on April 23, 2012, seeking approval to design, build and place into rates a 9,006 AFA desal plant.

• Application includes CEQA review by CPUC.

• Application also seeks permission to make desal plant smaller (5,506 AFA) if the GWR project can be realized in time. The decision to implement GWR will be based on several factors, including: cost, schedule, and public acceptance.

• ALJ expected to issue scoping memo soon which will layout CPUC schedule.

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Intake being Considered

Intake Wells

• Objectives: Limit intake of water from inland sources to the extent

practicable All water taken from beneath the seafloor beyond the shoreline.

• Method: Slant Wells, with screens placed under the seafloor and in 180-

foot formation.

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Slant Well – Typical Cross Section

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Slant Well – Estimated Depression Contours

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Extensive technical analysis of the potential effects and impacts of the slant wells on local and regional groundwater conditions in the SVGB was performed by Geoscience and Luhdorff & Scalmanini as part of the CEQA review for the Regional Water Project.  These are two of the leading groundwater consulting firms in the State.

CPUC is revisiting as part of their review of the project.

Test Slant Well

• Currently working on Test Slant Well to be located on Cemex property at southern end.

• Monitoring wells to be located 200 – 250 feet north of test slant well and would be used to verify geology prior to installation of slant well.

• We will work with MCWRA to develop a comprehensive monitoring program.

• Test well program is needed to gather more information as to geology, salinity, configuration, etc.

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Agency Act & Water Rights

• CAW will return 100% of all groundwater captured to the SVGB basin. Proposed action is consistent with Agency Act and California Water Rights Law.

• Options for Return to Basin: 1) CSIP 2) Drill injection well on CAW property, and 3) Make available for beneficial use to MCWRA or other party.

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Desalinated Water to be Returned to Basin

• Examples:

Assume 9,000 AFA plant capacity Assume 0% ground water capture (future 2030 condition) Annual return to be 9,000 * (% GW ) = 0 AFA

Assume 9,000 AFA plant capacity Assume 1% ground water capture (future 2030 condition) Annual return to be 9,000 * (% GW ) = 90 AFA

Assume 9,000 AFA plant capacity Assume 3% ground water capture (future 2030 condition) Annual return to be 9,000 * (% GW ) = 270 AFA

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CSIP Impacts if this Return to Basin Option Used

• Objectives: Increase water available to CSIP for agricultural irrigation Reduce Salinity of CSIP irrigation water

• Method: Returning a portion of desalinated water to CSIP will increase

supply and reduce salinity of CSIP’s irrigation water Adjusting salinity of desal supply will reduce salinity of CAW’s

combined water supply and reduce the salinity of wastewater generated by CAW’s customers.

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Salinity of Water Supply

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Post Desal

Existing Salinity

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FOR ILLUSTRATION PURPOSES

Proposed Salinity

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FOR ILLUSTRATION PURPOSES

with GWR Chlorides ~60mg/l

Questions

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