WATER SUPPLY PLANNING COMMITTEE
PRESENTATION
5.	UPDATE ON PROCESS FOR TRACKING WATER EXTRACTED FROM AND INJECTED INTO THE SEASIDE GROUNDWATER BASIN
Meeting Date:		May 4, 2020	Budgeted:	No
From:		David J. Stoldt	Program/	Water Supply Projects
		General Manager	Line Item:	N/A
Prepared By:		Jonathan Lear	Cost Estimate:	N/A
General Counsel Review: N/A
Committee Recommendation: N/A
CEQA Compliance: This action does not constitute a project as defined by the California Environmental Quality Act Guidelines section 15378.

SUMMARY: The Seaside Groundwater Basin consists of three water bearing hydrogeologic units. The layering in order of shallow to deep are the Aromas Dune Sands, the Paso Robles Aquifer, and the Santa Margarita Sandstone. There is production out of all three of the aquifer units. The Aromas Dune Sands hold brackish water and is the source water for the Sand City Desalination Plant. The Paso Robles Aquifer contains native groundwater and contains some shallow Cal-Am production wells as well as private wells. The Santa Margarita Sandstone also contains native water, however it is the target hydrogeologic unit for injection and storage of water. There are two types of water that are injected from two different water resources project. There are Cal-Am, City of Seaside, Golf Course, and private wells that produce water from the Santa Margarita Sandstone. The Carmel River Aquifer Storage and Recovery Project (ASR) injects groundwater produced from wells in the Carmel River Basin after it has been treated at the Begonia Iron Removal Plant. Pure Water Monterey (PWM) Project injects highly treated wastewater from the M1W plant north or Marina.

Water is tracked both volumetrically and chemically as each of the water types has a distinct chemical signature. Monitoring networks required by the Regional Water Quality Control Board, Department of Drinking Water, and the Seaside Groundwater Basin Watermaster provide data that allows District staff to define the areas of the Seaside Groundwater Basin where each water type exists.

Water injected by the Carmel River ASR project in counted on injection through meter reads at the ASR well heads. Similarly, PWM injected water is counted by meters at the injection wells associated with PWM. A total of how much water has been injected by each project and is currently in storage is kept by MPWMD staff at a daily time step. These ledgers are used in the Quarterly Water Budget Process when deciding how to best produce water in the most environmentally responsible manner. Water extracted by Cal-Am and the City of Seaside is measured by meters and reported to the District on a monthly basis. Private well owners report extraction totals to the District on a yearly basis.

To summarize, currently there are four types of water in the Seaside Groundwater Basin.

1. Brackish Water – located in the Aromas Dune Sands and provides the source for the Sand City Desalination Plant

2. Native Groundwater – Exists in the Paso Robles Aquifer and the Santa Margarita Sandstone.

3. Carmel River Basin Water – Injected into the Santa Margarita Sandstone by the Carmel River ASR Project.

4. Highly Treated Wastewater – Injected into the Santa Margarita Sandstone by the Pure Water Monterey Project.

Staff will provide a PowerPoint at the meeting to show the locations of the source waters and the injection and extraction locations for the Seaside Groundwater Basin.

RECOMMENDATION: Receive staff report.

EXHIBIT

None

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