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Former Exxon Service Station No. 73942 Page 3 of 3
<br /> 4444 North Pershing Avenue April 3, 2015
<br /> Stockton, California 95207
<br /> bentonite pellets that are hydrated for at least one-half hour; and the annular space
<br /> above the bentonite seal is filled to within one foot of the ground surface with a grout
<br /> mixture consisting of Type 1/II Portland neat cement with not more than three gallons of
<br /> water per forty-seven-pound sack of cement. If another well design is preferred, please
<br /> submit a second addendum with the proposed design for EHD review.
<br /> • Once MW15 has been installed, developed and surveyed, the EHD directs that the well
<br /> be sampled quarterly for one year; analyze the groundwater samples for TPHg, TPHd,
<br /> BTEX, MTBE, ETBA, TAME, DIPE, TBA, naphthalene and 1,2-dichloroethane
<br /> (1,2-DCA).
<br /> • The EHD directs that the soil samples collected during the advancement of soil boring
<br /> B2 (aka B15) and monitoring well MW15 be analyzed for 1,2-DCA and naphthalene in
<br /> addition to the list of compounds in bullet four above.
<br /> In Semi-annual Groundwater Monitoring Report, Fourth Quarter 2014, dated 23 January 2015,
<br /> Cardno has recommended that UVB and VW1 through VW5 be removed from the semi-annual
<br /> sampling schedule and personnel be mobilized to the site to open well PSV1. The EHD
<br /> concurs with Cardno's recommendations and directs that nested well PSV1 be opened, repaired
<br /> if necessary, and sampled quarterly for one year; analyze the groundwater samples for the
<br /> same constituents as groundwater collected from soon-to-be-installed monitoring well MW-15.
<br /> With the exception of MW14, IP1A/B, IP2A/B and IP3A/B, the top-of-casing elevations listed in
<br /> Semi-annual Groundwater Monitoring Report, Fourth Quarter 2014 differ from the elevations
<br /> listed in GeoTracker for wells surveyed on 16 October 2001. Also, the EHD has no record that
<br /> UVB and V1 were ever surveyed. Please submit the most current survey information to
<br /> GeoTracker for all wells associated with this site.
<br /> With these conditions and conditions listed in letter dated 23 December 2014, the EHD
<br /> approves the Addendum. Submit the access agreement, Master File Record form, Well and
<br /> Boring Permit application signed by a C-57 licensed contractor for each parcel, Licensed
<br /> Contractor Declaration, and permit fees for two borings and one monitoring well. The total fee
<br /> for advancing two borings onsite and one monitoring well off-site is $390. Any additional staff
<br /> time over the initial three-hour fee will be billed to the identified responsible party.
<br /> If you have any questions or concerns, please contact Vicki McCartney at (209) 468-9852 or by
<br /> e-mail at vmccartnevP—sicehd.com.
<br /> Sincerely,
<br /> Victoria L. McCartney, REHS Nuel C. Henderson, Jr., PG
<br /> Senior Registered Environmental Healthpecialist Engineering Geologist
<br /> c: Mr. Greg Gurss, Cardno ERI, 601 North McDowell Boulevard, Petaluma, California
<br /> 94954
<br /> Mr. James Barton, PG, California Regional Water Quality Control Board Central Valley
<br /> Region, 11020 Sun Center Drive, Suite 200, Rancho Cordova, California 95670
<br /> Ms. Diane Filippi, 370 Francisco Street, San Francisco, California 94133
<br />
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