Monday, September 28, 2015

CALIFORNIA COASTAL COMMISSION October 2015 Agenda Item: Request by California American Water Co. (Cal-Am) to amend permit condition associated with monitoring criteria used to determine type and extent of pump test effects as part of test slant well feasibility study, at the site of CEMEX sand mining facility, Marina, Monterey County. (TL-SF)

Ccc Addendum Tu15a 10 2015

Addendum to A-3-MRA-14-0050 and 9-14-1735 – California American Water Company Test Well

ABSTRACT: RE: 15. PERMIT AMENDMENTS. a. Permit No. 9-14-1735-A1 and A-3-MRA-14-0050-A1 (California American Water Company, Marina) Request by California American Water Co. (Cal-Am) to amend permit condition associated with monitoring criteria used to determine type and extent of pump test effects as part of test slant well feasibility study, at the site of CEMEX sand mining facility, Marina, Monterey County. (TL-SF) . The California Coastal Commission is scheduled to consider the aforementioned PERMIT AMENDMENT agenda item at the Commission’s Tuesday, October 6, 2015 meeting at the Long Beach Convention & Entertainment Center, Long Beach, CA. Staff Recommendation: Approval with conditions. The SUMMARY OF STAFF RECOMMENDATION is reproduced; the STAFF REPORT: MATERIAL AMENDMENT document copy is embedded.
Weiss Associates
Environmental Science, Engineering and Management


In November 2014, the Commission approved California American Water’s (“Cal-Am’s”) proposal to construct, operate, and decommission a test slant well and associated monitoring wells and other infrastructure near the shoreline of Monterey Bay in the City of Marina. The proposed project was to be used to conduct a pumping test program for up to about two years to obtain data regarding the geologic, hydrogeologic, and water quality characteristics in aquifers underlying the project area, which are within the coastal portion of the Salinas Valley Groundwater Basin, a regionally important source of agricultural and municipal water supply. In addition to the independent value of these data, information developed from the project is meant to help determine whether a similar subsurface intake system at or near this location could provide source water for a seawater desalination facility Cal-Am is separately proposing as part of the Monterey Peninsula Water Supply Project, which is the subject of an application and environmental documents being reviewed by the California Public Utilities Commission (“CPUC”). The CPUC’s review includes modeling, monitoring, and data analysis by the Hydrogeology Working Group (“HWG”), which consists of several licensed hydrogeologists representing stakeholders in the area.

The Commission’s approval included Special Condition 11, which required Cal-Am to install onsite and offsite monitoring wells and equipment, and established allowable thresholds for changes in groundwater levels and salinity to prevent the project’s pumping tests from causing adverse effects on nearby agricultural wells. If these thresholds were reached during the pumping test at the most distant onsite monitoring well, Cal-Am was to shut down the test and request a determination from the HWG and the Commission’s Executive Director as to whether the pumping test was causing the changes. If any part of the change was determined to be due to the pumping test, Cal-Am was to not re-start the pumping test until receiving an amendment to its coastal development permit.

In early 2015, Cal-Am completed installation of project components and in February 2015 started its pumping test. It ran until June 5, 2015, when monitoring detected that groundwater levels were approaching the allowable threshold. Cal-Am stopped the test, conferred with the HWG and the Commission’s Executive Director, who determined that the pumping test had resulted in a small percentage of the overall groundwater decrease, and applied for the required permit amendment on July 27, 2015.

Cal-Am’s proposed amendment would modify Special Condition 11. The primary modification would keep the same numerical groundwater and salinity thresholds as previously approved, but would provide that they be compared to regional trends rather than be based on a static value at a single location. This modification is in recognition of monitoring data collected from early 2015 until the present that show the pumping test resulted in minimal effects at the monitoring well that were not evident at more distant monitoring sites, and that those minimal effects could readily be distinguished from other regional influences, such as municipal and seasonal agricultural groundwater pumping, that were causing much greater changes. The proposed modification specifically acknowledges these regional influences and direct the HWG and the Executive Director to consider them in their analyses. Other proposed changes to Special Condition 11 would provide additional clarity to the condition language (e.g., referring to “groundwater” rather than “water”).

As part of its review, Commission staff obtained the services of an independent licensed hydrogeologist to evaluate the relevant modeling and monitoring data and to review Cal-Am’s proposed modification. That review resulted in conclusions that the threshold values and monitoring approach were appropriate for preventing impacts to agricultural groundwater users further inland and that the pumping test was not expected to cause any measurable effect on those groundwater users.

Staff recommends the Commission approve the proposed Findings and modifications to  Special Condition 11.
Application No.: 9-14-1735-A1 and A-3-MRA-14-0050-A1
Applicant/Appellant: California American Water Company

Project Location: At the site of the CEMEX, Incorporated sand mining facility, Lapis Road, City of Marina, Monterey County. (APN #203-011-001 and #203-011-019)
Description of Previously Approved Project: Construct and operate a test slant well and associated monitoring wells to both develop data and assess the feasibility of the project site as a potential long-term water source for a desalination facility.
Staff Recommendation: Approval with conditions

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