|
r�TTJr� Well Destruction Workplan
<br /> ATC Jamar Service Station
<br /> Page 4 of 5
<br /> ATC performed an evaluation of site conditions with regard to the State Water Resources Control
<br /> Board Low-Threat Underground Storage Tank Case Closure Policy. The results were presented in
<br /> ATC's No Further Action Request (Revised) and First Semiannual Monitoring Report 2019 dated,
<br /> November 9, 2019. ATC concluded that all of the media-specific criteria of the Low-threat
<br /> Underground Storage Tank Case Closure Policy appeared to be satisfied.
<br /> In August 2020, ATC supervised the advancement of CPT-8 and an adjacent HydroPunch® boring off
<br /> site approximately 360 and 190 feet east of monitoring wells MW6C and MW10C, respectively, in an
<br /> effort to confirm the contaminant plume modeling results presented in the No Further Action Request
<br /> (Revised) and First Semiannual Monitoring Report 2019 dated, November 9, 2019. A groundwater
<br /> sample was collected from the adjacent HydroPunch® boring at a depth of 107-112 feet bgs, and
<br /> analyzed for TPHg, BTEX, and fuel oxygenates with 1,2-DCA and EDB. These constituents were not
<br /> detected in the groundwater sample and ATC recommended no further investigation be conducted at
<br /> the site. The CRWQCB concurred with the recommendations.
<br /> A Public Notice was sent to select property owners, tenants, and government agencies inviting them
<br /> to comment on ATC's request for closure. The comment period ended on June 6, 2021, with no
<br /> comments received by the CRWQCB.
<br /> SCOPE OF WORK
<br /> Planninq and Permitting
<br /> Following approval of the workplan, Atlas will obtain the necessary permit documents from the
<br /> SJCEHD for the well destruction activities. Atlas will also obtain encroachment permits from the San
<br /> Joaquin County Department of Public Works for conducting work in the roadway right-of-way. Atlas
<br /> will schedule field personnel and equipment, notify Underground Services Alert to locate
<br /> underground utilities as required, and perform other necessary field preparation and job start-up
<br /> activities.
<br /> Well Destruction Activities
<br /> The existing well network consists of ten on-site monitoring wells(MW1, MW1 C, MW2, MW3, MW3C,
<br /> MW4, MW5, MW8, MW12A, and EW1), five dual completion on-site injection wells (IW1 through
<br /> IW5),two single completion on-site injection wells (IW6 and IW7),three on-site vapor extraction wells
<br /> (VE1, VE2, and VE3), three on-site vapor extraction wells (VEW1, VEW2, and VEW3), and 18 off-
<br /> site wells (MW6A, MW6B, MW6C, MW7A, MW7B, MW7C, MW9A, MW9B, MW9C, MW10A,
<br /> MW10B, MW10C, MW11A, MW13A, MW13B, MW13C, MW14B, and MW14C). The locations of the
<br /> wells are shown on Figures 2 and 3. The wells are installed to depths ranging from approximately 50
<br /> to 111 feet bgs.
<br /> All of the groundwater monitoring wells and vapor extraction wells are constructed of 2-inch diameter
<br /> Schedule 40 poly-vinyl chloride (PVC), with the exception of EW1, which is constructed with 4-inch
<br /> diameter Schedule 40 PVC. The five dual completion injection wells (IW1 through IW5) are
<br /> constructed with 0.75-inch diameter Schedule 80 PVC and the two single completion injection wells
<br /> (IW6 and IW7) are constructed of 3-inch diameter Schedule 80 PVC. Well completion details are
<br /> summarized in Table 1.
<br /> Soil samples were collected from most of the boreholes associated with the wells during well
<br /> installation activities and submitted for laboratory analyses. Available soil data associated with the
<br /> monitoring wells are presented in Table 2. Groundwater quality data are included in Table 3.
<br />
|