Meeting Date:

August 14, 2017





David J. Stoldt


Water Supply Projects


General Manager

Line Item No.:



Prepared By:

Jonathan Lear

Cost Estimate:



General Counsel  Review:  N/A

Committee Recommendation:  The Administrative Committee reviewed this item on August 14, 2007 and recommended ______________.

CEQA Compliance:   This action does not constitute a project as defined by the California Environmental Quality Act Guidelines section 15378.




















SUMMARY:  As the District and CalAm move forward with their water supply projects, Pure Water Monterey and Desalination respectively, new sources of water will be manufactured, injected and stored in the Seaside Groundwater Basin.  As a component of the permitting process, each project will require to enter into an agreement with the Seaside Watermaster to inject and store water in the Seaside Groundwater Basin.  The Seaside Adjudication Decision requires that no actions by any groundwater producers cause material damage to any other groundwater producer.  Because of this, a component of the agreement to store and recover water will require each project owner/operator to demonstrate that storage of their water will not cause damage to the Seaside Groundwater Basin or material damage to other groundwater producers. 


DISCUSSION:  Staff proposes to retain Pueblo Water Resources to assist the District with an investigation of water quality impacts and changes in water quality during Aquifer Storage and Recovery operations.  Years of water quality data have been collected to meet regulatory requirements for the Regional Water Quality Control Board.  These data have shown sporadic increases in some water quality parameters during aquifer storage and recovery cycles.  While not fully understood, some of these data have led the District staff to believe the source of the water quality changes may be the interaction of injected water from the Carmel Valley Alluvial Aquifer with the minerology of the Santa Margarita Sandstone.  The proposed sampling is designed to determine the geochemical process(es) occurring between injected water and the aquifer minerology and help with forecasting potential water quality changes associated with long-term water storage in the Seaside Groundwater Basin.  The data set generated from this sampling will be used to populate a geochemical model that will demonstrate injection of Pure Water Monterey water will not cause damage to the Seaside Groundwater Basin or create long-term unintended changes in water chemistry.


In addition, District staff believes that a well calibrated geochemical model is a necessary tool to help predict and verify the geochemical interactions between the Seaside Groundwater Basin minerology and the mixing of Carmel Valley Alluvial, Pure Water Monterey, Desalinated, and Native Seaside Basin groundwater.  This geochemical model will also be used and maintained to manage future ASR operations targeting the Seaside Groundwater Basin to store water which is consistent with the District’s Mission Statement to protect water resources. 


RECOMMENDATION:  Staff recommends the Board authorize the General Manager to enter into an agreement for $120,137 with Pueblo Water Resources to complete the Supplemental Sampling and Analysis Plan to generate the data necessary that will be used to construct a geochemical model of the Seaside Groundwater Basin.      


BACKGROUND:  The District completes annual water quality monitoring at the ASR facilities as outlined in the ASR Sample and Analysis Plan, which is a requirement for project operations by the Regional Water Quality Control Board.  Because the chemistry of water produced from wells in Carmel Valley differs from the chemistry of the native groundwater in the Seaside Groundwater Basin, district staff and regulators have noticed water quality changes resulting from injection that cannot be explained by the simple mixing of two water types.  Although the origin of the water quality changes are not understood completely, recent work has brought District staff to the hypothesis that changes in water chemistry are related to the dissolution of trace minerals that have been identified to exist in the Santa Margarita Sandstone.  


IMPACT TO STAFF/RESOURCES:  Funds for this project are included in the FY 2017-18 budget under “Water Supply Projects,” line item 1-2-1.  Funds expended to complete this work will be shared between the District and CalAm through the ASR Management and Operations agreement between the District and CalAm. Staff time will be utilized to aid the consultant in sample collection.



6-A      Proposal for Supplemental Sample and Analysis Water Quality Investigation from Pueblo Water Resources

6-B      Sample and Analysis Plan outlining annual ASR project monitoring as required by the Regional Water Quality Control Board