|
0
<br />Proposal for
<br />Various Environmental Services
<br />Table S. Chronological List of Historical Events at the Former Arco Gas Station
<br />Page 36
<br />August 1, 2022
<br />Document Date
<br />Document Type
<br />Consultant/Agency
<br />Notes
<br />Dormancy status (redo... sampling f equ...y to semi-annual basis/ monitoring to only 3 wells) rejected due to:
<br />Elevated/Fluctuating Levels of Fuel Oxygenates present in perimeter, Wall BH-8 (adjaeent to western
<br />January 05 2005
<br />Request for Dormancy
<br />Delta Environmental Consultants
<br />USTIOispe...r ). High concentrations of Benzene in Wall BH-2 (former UST.; Southeast boundary) not wall
<br />defined. Sampling frequency (reduced from quarterly to annually) of Wells BH 1,11,12,13,14, and 18. Sampling
<br />frequency (must remain quarterly) for wells BH-6, 10 and remainder of Wells
<br />Quarterly Update Report
<br />Report aubmittad January 27, 2005:
<br />January 27 2005
<br />Submittal
<br />Delta Environmental Consultant.
<br />Verbiage for previous quarters update report was Incorrectly left in this repo:. Resubmitted February T, 2005
<br />Work Plan for Additional
<br />Proposed Scope of We-:
<br />January 28 2005
<br />Groundwater
<br />Delta Environmental Consultants
<br />Install anew monitoring well I ... tad ... [/southeast of the former UST., a 1v.... one soli boring BH-19 to a
<br />Assessment
<br />depth of 22 it bgs and place screen from 5 ft bgs to total depth
<br />Resubmittal correcting previous Quarterly Submittal (4th Quarter 20") Jan 30, 2005:
<br />February OT 2005
<br />Quarterly Update Report
<br />Della Environmental Consultants
<br />Grou-i-st., monitoring ...ducted (no -purge sampling) D... mber 17, 20"
<br />Submittal
<br />Analyzed for THG-g, BTEX, MTBE. Groundwater was not collected for Wells ON. 1, 11 through 14, and 18
<br />Workplan for Additional
<br />Water Board Approved:
<br />February 15 2005
<br />Groundwater
<br />Santa Ana Water Board
<br />One additional groundwater monitoring will be installed (to delineate lateral extent of high benzene
<br />Assessment
<br />,ntmtl... ) In well BH-2 (east-southeast of UST exeavatlon/adjaeent residential complex)
<br />Request to cancel additional work plan Implamant.U.. because the utility location and geophysical survey
<br />Request to Rescind
<br />ques
<br />ondu.t.d on April 21, 2005, concluded the proposed well could not be safely installed. It was requested that
<br />June 09 2005
<br />AGroundwater
<br />Additional
<br />Della Environmental Consultants
<br />alternative site eharocterizallon melhotla to be consitlerea or requirement of additional assessment to be
<br />Assessment
<br />.gma.a
<br />Revised Work Plan for
<br />May 15 2006
<br />Additional Ground Water
<br />Della Environmental Consultants
<br />Request to rescind from June 09, 2005 was denied through a phone call conversation on June 22, 2005
<br />Assessment
<br />Location of BH-19 revised to avoid utility interference
<br />On July 3, 2006 the proposed location of BH-19 was adjusted because a 12-inch concrete piping was found in the
<br />proposed revised location, therefore the well location was moved 3 feet North
<br />August 17 2006
<br />Off -Site Well Installation
<br />Delta Environmental Consultants
<br />No detectable concentrations of benzene, toluene, ethylb... e c, total xylenes, MTBE, TBA, DIPE, ETBE, TAME
<br />Status Report
<br />or ethanol were found for the soil collected from BH-19. Soil Sample BN-19-10 has no detectable concentrations
<br />of BTEX, MTBE or TBA but had TPH-g .....nation of 290 mg/kg
<br />Resolution No. 2009-0042 was ad.pt.d May 19, 2009 this resolution mandates that agencies reduce quarterly
<br />monitoring requirements to a semi-annual basis unless sit¢ specific needs warrant otherwise:
<br />July 28 2009
<br />Staff Letter
<br />Santa Ana Water Board
<br />Based on evaluation Wall. BH 2 through 4, T through 9, and 15 through 17 may be reduced to semi-annual
<br />mpling schedule
<br />Proposed adv... ent and sampling of 3 boring samples (C3B-1 through 3) In the areas of former dispenser
<br />August 31 2011
<br />Work Plan for
<br />Stratus Environmental, Inc.
<br />island, UST. and product lines.
<br />Co motion Soil Borings
<br />Samples will be analyzed for Gasoline Range Organics, BTEX, MTBE, DIPE, ETBE, TAME, TBA and ethanol
<br />Revised Workplan for
<br />Advancement. of proposed soil boring location of August 31, 2011 to a depth of 15 ft Bgs, approximately 5 it
<br />November 10 2011
<br />Confirmation Soil Borings
<br />Stratus Environmental, Inc.
<br />into groundwater
<br />Approval of Revised Work Plan for Confirmation Soil Borings dated November 16 ,2011 where 3 soil borings be
<br />January 05 2012
<br />Staff Letter
<br />Santa Ana Water Board
<br />advanced to approximately 15 feet bgs and samples eollaet,d from each borehole at 5-foot intervals
<br />Air monitoring conducted during exeavatlon activities during March 3, 2012 where the breaking and removal of
<br />April OB 2012
<br />Rule 1166 Soil Monitoring
<br />Stratus Environmental, Inc.
<br />asphalt and excavation of pea gravel and soil was conducted.
<br />Report
<br />VOC concentrations were not detected during excavation activities
<br />First Quarter 2012 jApol 30, 2012):
<br />work performed this quarter. submitted in the Quarterly Monitoring Report, Fourth Quarter 2011 on January 30,
<br />April 30 2072
<br />Quarterly Status Report
<br />Stratus Environmental, Inc.
<br />2012. No groundwater.ample. ware collected. Implemented the Revised Work Plan for Confirmation Soil
<br />Borings, dated November 10, 2011, on March 15 and 16, 2012
<br />Confirmation of four soil borings to 15 ft bgs (CSB 1 through 4)
<br />Elevated concentrations of petroleum hydrocarbons, including benzene, were detected in ne r surface soils in
<br />May 14 2012
<br />Confirmation Soil Boring
<br />Stratus Environmental, Inc.
<br />areas corresponding to both the former tanks and western dispans¢r area. The highest concentrations of TPH-9,
<br />Report
<br />benzene, xylenes, TMBs and naphthalene were encountered in CB-1 (10 feet bgs; southeast corner of site).
<br />Residual hydrocarbons were detected to total depth at all four drill locations
<br />Be.etl on the results of the Confirmation Soil Boring Report, agency required air-sparge wells AS-1 and AS-2 to
<br />July 12 2012
<br />Staff Letter
<br />Santa Ana Water Board
<br />be sampled during next groundwater event, and soil vapor survey and risk assessment to be completed to
<br />determine the potential vapor intrusion threat posed by shallow residual contamination
<br />Non-compliance, failing to respond to directive, which required that a soil vapor survey and risk assess m¢nt to
<br />February 28 2013
<br />Staff Letter
<br />Santa Ana Water Board
<br />be performed to evaluate the potential threat to human health posed by the elevated residual petroleum
<br />hydrocarbons enc unt.red in soils during confirmation sampling.
<br />Response to Non -Compliance by Straus: The newly adopted [at the time] Low.Threat Closure policy stales
<br />evaluation of the potential petroleum vapor intrusion to indoor air is not required at active commercial
<br />March 29 2013
<br />Workplan for Shallow Soil
<br />Stratus Environmental, Inc.
<br />petroleum fueling facilities, lithology of subject site indicated release characteristics do not pose a threat to
<br />Vapor Survey
<br />pen gency's request, prepare a
<br />human health. To res d to a t, however, Straus will Work Plan to conduct a risk
<br />ent and a shallow sell vapor survey In general accordance with the DTSC Advisory
<br />Work Plan Approved, but all hydrocarbon related compounds with established screening levels must be
<br />quantified to sufficiently low limits to allow for comparison against California Human Health Screening Levels
<br />May 23 2013
<br />Staff Letter
<br />Santa Ana Water Board
<br />(CHHSL.). Due to the very close proximity of adjacent residential structures, the resulting site data must be
<br />valuated under both commercial and residential exposure scenario
<br />Responsibility of the Arco Site had transferred from Atlantic Richfield Company to Tesoro Refining and
<br />July 3 2013
<br />Owner Letter
<br />Tesoro Refining & Marketing, LLC
<br />Marketing, LCC effective June 1, 2013
<br />Workplan for Additional
<br />Two (2) hand -auger borings be advanced In the vicinity of the current and former waste ell lank, In order to
<br />April 30 2014
<br />Site Assessment
<br />Stratus Environmental, Inc.
<br />collect more detailed information on subsurface conditions near this potential area of concern.
<br />Additional Site
<br />In order to assess the presence of petroleum hydrocarbons In the vicinity of the existing waste oil tank, two soil
<br />August 22 2014
<br />Assessment Report
<br />Stratus Environmental, Inc.
<br />borings (HA-1 andHA-2) ware advanced and results were presented.
<br />Regional Board staff has determined this environmental cleanup case eligible for site closure. Groundwater
<br />October 30 2014
<br />Determination of
<br />Santa Ana Water Board
<br />monitoring and sampling activities may be reduced to an annual frequency (performed 2nd Quarter) pending site
<br />Eligibility for Closure
<br />closure
<br />Work Plan to perform additional soil sampling associated with the removal of the underground storoge tanks
<br />Work Plan fo r Soil
<br />(USTs), waste oil tank, hydraulic hoist, fuel dispensers and product piping.
<br />May 7 2079
<br />Borings and oil
<br />Stratus Environmental, Inc.
<br />Sampling of fourteen soil borings associated with USTs, waste oil tank, and hydraulic lifts and the collection of
<br />Piping Sampling
<br />oil samples along the product piping and fuel dispense -
<br />Destruction of eleven onsite groundwater monitoring wells (BN-1 through BN-4, BN-6, BN-8, and BN-13 through
<br />September 6 2019
<br />Well Destruction Report
<br />Stratus Environmental, Inc.
<br />BH-11 antl two o site dual nested air-sparge wells (AS-1 and AS-2) The wells were removed to facilitate site
<br />tlemolition asset ated with the City of Santa Ana's street widening project
<br />Communications on October 8 and 21, 2019 and January T, 2020 between Regional Water Board staff and State
<br />Revised Review
<br />Water Boartl staff, the following scope was disco ... d and agreed upon: The Site meets LTCP criteria for current
<br />January 23 2020
<br />Summary Report -
<br />State Water Resources Control
<br />relal land use, It Is reasonable to re-evaluate Site conditions against the Policy when the future property
<br />Concur with Closure
<br />Board
<br />us.has been determined, Responsible party should contact the Department of Water Resources to
<br />onfirm/verify the location of the supply well, supposedly located less than 500 feet east of the Site.
<br />Concurrence of Site
<br />Closure Recommendation
<br />Evaluated nearby water -supply walls and confirmed that the walls do not exist. No further groundwater sampling
<br />May 6 2020
<br />8 Cancellation of Annual
<br />Stanlee Consulting Services Inc.
<br />of the six off -site street groundwater monitoring wells was needed
<br />Groundwater Sampling
<br />Notification of Case
<br />Based on available data, the gasoline contamination in soil and/or groundwater beneath the site appears to have
<br />May 4 2021
<br />Closure
<br />Santa Ana Water Board
<br />been adequately d and mitigated and environmental ease closure may appropriate be a late at this time.
<br />qua y assess. ga
<br />Well Destruction
<br />Removal and/or abandonment of all walls and other site improvements related to the underground storage tank
<br />September 9 2021
<br />Directive
<br />Santa Ana Water Board
<br />cleanup must be done before a final case closure summary
<br />The destruction of six off -Site groundwater monitoring well. (BH-T, BH-9 through BH-12, and BH-18) part ormea
<br />November 23 2021
<br />Well Destruction Report
<br />Stantec Consulting Services Inc.
<br />November 8 through 10, 2022
<br />Agency finds that the site investigation and corrective action carried out at the above-r.f.r.n..d UST site is in
<br />March 23 2022
<br />Closure Letter and Final
<br />Santa Ana Water Board
<br />c mpliance with the requirements and with corrective action regulations set and that no further action related
<br />Gas¢ Summary
<br />to the petroleum releases(.) at the site is required.
<br />40 A -Tech Consulting, Inc.
<br />
|