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Site Report: Portage Chevron Service Station 9-2609

Site Name: Portage Chevron Service Station 9-2609
Address: Mile 79 Seward Highway, Portage, Girdwood, AK 99587
File Number: 2110.38.007
Hazard ID: 2007
Status: Active
Staff: Rebekah Reams, 9074512144 rebekah.reams@alaska.gov
Latitude: 60.818090
Longitude: -148.978070
Horizontal Datum:WGS84

We make every effort to ensure the data presented here is accurate based on the best available information currently on file with DEC. It is therefore subject to change as new information becomes available. We recommend contacting the assigned project staff prior to making decisions based on this information.

Problems/Comments

Petroleum contamination of soils and groundwater was documented during a preliminary site assessment for ADOT in 1993. The on property drinking water well was found to be contaminated with benzene, it was properly abandoned and replaced on October 8, 2001 with a new drinking water well drilled to 100 feet below ground surface (bgs) that is currently not in use (which draws water from 43 to 49 feet bgs where the 6 inch steel casing was perforated) that was initially tested and found to be free of petroleum contamination, but has periodically had detectable contamination (DRO, RRO, and toluene) from 2012 to 2017. The depth to groundwater in the drinking water well has ranged between 8.88 to 11.02 feet below ground surface and the base of the well was measured at 78 feet below ground surface. Three groundwater monitoring wells were installed in 1995. Five additional monitoring wells were installed in 1998. In 1998 eleven soil borings were drilled at the site. Up to 2,490 mg/kg DRO, 5,970 mg/kg GRO, and 223 mg/kg BTEX was found in the soil borings. In the summer of 2000 four underground storage tanks, a septic tank, a log crib, and 3,500 cubic yards of contaminated soil was excavated and thermally treated, and 7,500 gallons of contaminated water was removed and treated. The depth of the excavation ranged from 4 to 16 feet below ground surface. Soil contamination remains at the site at the sidewalls of the excavation (up to 2,670 mg/kg GRO, 1,150 mg/kg DRO, and 32.9 mg/kg benzene), and the base of the excavation (up to 2,900 mg/kg GRO, 1,750 mg/kg DRO, and 9.6 mg/kg benzene). On June 2, 2008 six soil borings were drilled and a replacement monitoring well was installed (MW-14). Up to 2.2 mg/kg benzene, 3,800 mg/kg GRO, and 4,000 mg/kg DRO was found in the soil areas sampled. Groundwater monitoring of the monitoring wells and the currently not in use replacement drinking water well continues at the site. In 2009 soil borings SB09-1 and SB09-2 were advanced to a depth of 18 feet and converted to monitoring wells MW-15 and MW-16 were installed. In 2012 a soil vapor probe was installed north of an abandoned kiosk to evaluate vapor intrusion potential at the site. This soil vapor probe was not able to be sampled due to the screen being submerged.

Action Information

Action Date Action Description DEC Staff
1/21/1994 Update or Other Action (Old R:Base Action Code = SA1R - Phase I SA Review (CS/LUST)). Review of R&M Consultants report for ADOT proposed upgrade and channelization project at the junction of Portage Glacier Road. and Seward Highway. Former Staff
2/14/1994 Site Added to Database DRO. Former Staff
6/1/1994 Update or Other Action (Old R:Base Action Code = RPL1 - Initiate Dialog with RP). AG's office sent first of PRP letter series to Robert Hall (site owner) and Chevron USA Products Company. Response requested within 30 days of receipt. Former Staff
5/6/1998 Update or Other Action ADEC file review letter, including "Phase II Site Assessment" report dated November 7, 1995, subsequent groundwater monitoring reports, and the most recent groundwater monitoring report, "3rd Quarter 1997 Monitoring Report 970909-S-1". ADEC requested characterization of groundwater contamination and installation of monitoring wells. 1) Characterize soil and groundwater contamination: Eileen Olson
7/2/1998 Site Characterization Workplan Approved ADEC approval of "Work Plan for Assessment" dated June 15, 1998. Eileen Olson
12/1/1998 Document, Report, or Work plan Review - other ADEC review of "3rd Quarter 1998 Monitoring Report" and request for additional characterization of groundwater contamination. Eileen Olson
12/21/1998 Document, Report, or Work plan Review - other Submittal by Chevron of report "Installation of Monitoring Wells". Ongoing quarterly monitoring of wells. Eileen Olson
4/17/2000 Meeting or Teleconference Held Met with Chevron and SECOR representatives to discuss plans for summer 2000, which will include excavation of contaminated media and installation of additional monitoring wells. Eileen Olson
7/25/2000 Document, Report, or Work plan Review - other Partial approval of "Work Plan for a Method 3 Human Health and Method Ecological Risk Assessment and Additional Site Assessment." Approved proposed hot-spot excavation and installation of three additional monitoring wells. Requested additional MTBE sampling as one shallow groundwater monitoring well sample concentration of MTBE was 0.1 mg/l. Also noted that a copy of the work plan has been forwarded to the Department’s Risk Assessor, who will review and comment on the proposed human health and ecological risk assessments. Eileen Olson
8/30/2000 Meeting or Teleconference Held Meeting with SECOR representative regarding water treatment for 7,500 gallons of water primarily from tanks discovered during recent work. Also discussed site remediation options, and the fact that, so far (with work still in progress), at least ten times as much soil has been excavated as was expected to be contaminated. Eileen Olson
9/5/2000 Document, Report, or Work plan Review - other Review letter approving “Work Plan for the Treatment and Disposal of Petroleum Hydrocarbon Impacted Water.” The plan proposed the filtration of approximately 7,500 gallons of petroleum hydrocarbon contaminated water through a GAC filtration system into a holding tank. Filtered water was to be sampled and the results provided to the Department. If analytical results showed that the water does not exceed water quality standards, the Department would approve discharge of the water to the ground surface. Eileen Olson
8/18/2001 Document, Report, or Work plan Review - other Comments on RA work plan received from ADEC risk assessor Stephanie Pingree. Response from Chevron's consultant is that work plan is not complete and was submitted prematurely. A new one will be submitted in the future. Eileen Olson
12/12/2001 Document, Report, or Work plan Review - other Received Letter Report from Chevron's consultant documenting the drilling and groundwater sampling of a new domestic non-potable production water well on the subject property. This well was installed on October 8, 2001 at the current property owner's request and replaces a well condemned by ADEC due to high benzene concentrations. The 6 inch steel well casing is perforated at 43 to 49 feet below ground surface (bgs), and was drilled and cased 100 feet with an end cap. The drilling identified fill from 0 to 2.5 feet, silt from 2.5 to 7 feet, silty sands from 7 to 24 feet, gravelly sand from 24 to 54 feet, sand from 54 to 73 feet, and silty clay from 73 to 100 feet bgs. The soils were wet from 3 feet to 73 feet bgs. The static water level in the well after drilling was 3 feet bgs. Water production was estimated at 5 gallons per minute. The well was installed using an air rotary drill rig. From the well construction log it does not appear that the space on the outside of the casing was sealed at any depth. After drilling the well water was sampled and it was non-detect for BTEX, GRO, MTBE, 1,2-DCA, and 1,2-DBA. Eileen Olson
2/21/2002 Document, Report, or Work plan Review - other Received Second Semi-Annual Event of September 27, 2001 Special Event of October 5, 2001, Groundwater Monitoring and Sampling Report. Eileen Olson
4/17/2002 Document, Report, or Work plan Review - other Between August 21, 2000 and September 7, 2000 four underground storage tanks, a septic tank, a log crib, 3,500 cubic yards of contaminated soil was excavated and thermally treated, and 7,500 gallons of contaminated water was removed and treated. The depth of the excavation ranged from 4 to 16 feet below ground surface. Soil contamination remains at the sidewalls of the excavation (up to 2,670 mg/kg GRO, 1,150 mg/kg DRO, and 32.9 mg/kg benzene), and the base of the excavation (up to 2,900 mg/kg GRO, 1,750 mg/kg DRO, and 9.6 mg/kg benzene). Eileen Olson
6/7/2002 Update or Other Action ADEC sent letter requested additional information regarding Excavation of USTs and Petroleum Impacted Soils report to RP and consultant. Beatrice Egbejimba
2/13/2003 Document, Report, or Work plan Review - other Staff received the Site Assessment Report, prepared by SECOR International, Inc., November 13, 2002. The report documented the installation of four groundwater monitoring wells and collection and analysis of four soil and four groundwater samples. Maximum soil contamination was 464 mg/kg DRO and 0.426 mg/kg benzene in MW-11. Maximum groundwater contamination was 20 mg/L DRO in MW-11 and 0.05 mg/L benzene in MW-9. Since these samples exceed the approved cleanup levels for this site, the Department recommends continued semi-annual groundwater monitoring. The analysis detection limits for benzene exceeded the reporting limits, and hence, the applicable cleanup level, in four soil samples and one groundwater sample. It is recommended SECOR work with the laboratory to remedy this issue prior to the next monitoring event. ADEC requested Chevron provide information on the disposal of investigation derived waste from this investigation. The Department requested the following information as previously requested in the Department’s letter dated June 7, 2002: a) On September 20, 2000 SECOR, on behalf of Chevron, requested authorization to transport and dispose of treated water for secondary treatment and disposal at Energy Recovery Services (ERS) in Anchorage. Activated carbon was used to treat contaminated water. Analytical results of the treated water indicate that benzene was still present at 0.0325 mg/L, toluene at 0.125 mg/L, ethylbenzene at 0.0208 mg/L, P & M xylenes at 0.0775 mg/L and o-xylene at 0.0289 mg/L. The ADEC granted approval via e-mail for the transport and disposal of treated water at ERS. The Excavation of UST’s and Petroleum Impacted Soils report indicates that treated water was discharged to the ground following successful treatment. Requested clarification how treated water, sludge from water treatment and spent activated carbon were disposed. b) Approximately 3,500 cubic yards of excavated soil was transported to Alaska Soil Recycling for treatment and treated water may have been transported to ERS during the 2000 cleanup event. Requested Chevron provide certificates of disposal for this, and any other, transported material, as is required by ADEC. Elizabeth Stergiou
7/21/2003 Document, Report, or Work plan Review - other ADEC received groundwater monitoring and sampling report. Beatrice Egbejimba
9/4/2003 Update or Other Action ADEC sent letter to Robert Cochran regarding Groundwater Monitoring and Sampling report received July 23. 2003. The report was approved subject to the sampling of all existing wells in the future. A review of file information shows that monitoring well MW-4 has missed 3 sampling events, MW6 has missed 6 sampling events, MW-7 has missed 2 sampling events and MW-12 has missed 3 sampling event. Elevated levels of DRO and GRO are still been reported with a maximum of 11mg/kg GRO and 6.4mg/kg DRO. Beatrice Egbejimba
12/4/2003 Meeting or Teleconference Held ADEC met with representatives of Chevron (RP) and Robert Hall (current property owner) to discuss future cleanup actions at the site. During the meeting it was discussed that it may not be practical to excavate all of the remaining soil contamination at the site. A verbal proposal to apply method three cleanup levels at the site was made by the RP. ADEC requested a work plan identifying pathways to be evaluated. Any conditional closure status would be contingent on the approval on a soil cleanup level and groundwater monitoring results. Other issues discussed at the meeting were the use of groundwater as a drinking water source, the presence of methane gas in formations beneath the site, previous site conditions as well as possible soil and groundwater impacts from off-site sources. Beatrice Egbejimba
4/5/2004 Conceptual Site Model Submitted ADEC received a draft conceptual site model dated March 31, 2004 for the Chevron site. Phone calls were made to Brian Silva of SECOR to make sure that the land owner received a copy. Staff called land owner and encouraged him to review the document and comment when he receives his copy. A copy was e-mailed to him at the address he provided. The draft conceptual site model would be used prepare a Risk Assessment workplan for the site. Beatrice Egbejimba
4/6/2004 Document, Report, or Work plan Review - other ADEC reviewed the Second Semi-Annual-Event of October 3, 2003 Groundwater Monitoring and Sampling by Gettler-Ryan Inc. The report was received November 14, 2003. Based on the information provided, ADEC determined that the report was inadequate because several wells had not been sampled during this event and previous event. Data gaps exist and it is uncertain what contaminant levels are in specific areas of the site, and whether levels are increasing, decreasing or are stable in those areas. ADEC did not approve the report and an addendum was requested. Beatrice Egbejimba
4/26/2004 Update or Other Action Project Manager received e-mail from Brian Silva of SECOR indicating that the supplemental monitoring and sampling that was requested due to the second semi-annual event of 2003 being inadequate, was completed on April 3, 2004. All 10 of the wells were monitored and sampled. A report will be produced and sent to ADEC once analytical were available. Beatrice Egbejimba
5/12/2004 Update or Other Action ADEC received letter from RP (Chevron) stating that in response to ADEC's April 6, 2004 letter, MWH would conduct another monitoring event in April. Gettler-Ryan conducted previous monitoring events at the site. Beatrice Egbejimba
6/2/2004 Update or Other Action ADEC reviewed analytical results provided via e-mail by Brian Silva of SECOR. A report will be provided at a later date. ADEC will respond after review of the report. Analytical results indicated that all on-site wells were located and sampled. Beatrice Egbejimba
6/15/2004 Document, Report, or Work plan Review - other Addendum Second Semi-Annual Groundwater Monitoring Report received. Beatrice Egbejimba
8/19/2004 Document, Report, or Work plan Review - other Groundwater monitoring report received and reviewed. Eric Henry
1/7/2005 Document, Report, or Work plan Review - other ADEC receives a Method 4 Human Health and Ecological Risk Assesment Work Plan for this site. This work plan is spposedly based on discussions between Chevron, ADEC, and Robert Hall in Decemeber 2003. The Work Plan is currently under review by the ADEC risk assessor. Eric Henry
2/15/2005 Document, Report, or Work plan Review - other ADEC provides 12 comments to RP's consultant (Secor) regarding the proposed risk assessment work plan. Eric Henry
2/9/2006 Meeting or Teleconference Held Meeting with Chevron to discuss future site work. They are waiting on ADEC comments on the proposed risk assessment. We discussed that soil contamination remains not just near the highway but also at the base and other sidewalls of the former excavation. We also discussed that if the downgradient monitoring wells show levels exceeding cleanup levels, additional monitoring wells may be required to define the extent of the groundwater contamination at the site. Robert Weimer
2/24/2006 Document, Report, or Work plan Review - other Reviewed the monitoring report for the June 13, 2005 groundwater sampling. Up to 15 mg/l DRO and 8.1 mg/l GRO in the groundwater. The depth to groundwater was 4.00 to 8.93 feet below ground surface. The contamination concentrations are decreasing in some wells and increasing in others. Robert Weimer
2/27/2006 Document, Report, or Work plan Review - other Reviewed the monitoring report for the October 11, 2005 groundwater sampling. Up to 0.61 mg/l DRO and 0.19 mg/l GRO in the groundwater. The depth to groundwater was 1.39 to 5.62 feet below ground surface. Groundwater flow direction was to the northeast. The drop in contaminant concentrations appears to be related to the groundwater fluctuations at the site. When depth to groundwater is shallow the contamination is lower (as it was on this monitoring event), but when the groundwater drops the contamination concentrations are higher (up to 15 mg/l DRO, and 8.1 mg/l GRO on 6/13/05 when groundwater was about 2 feet deeper). Robert Weimer
3/21/2006 Update or Other Action Faxed copy of the 1/27/05 ADEC risk assessment comments to Chevron. It appears that they were emailed to Chevron consultant back on 2/15/05. Robert Weimer
9/6/2006 Document, Report, or Work plan Review - other Reviewed the monitoring report for the May 8, 2006 groundwater sampling. Up to 3.4 mg/l DRO and 0.35 mg/l GRO in the groundwater. The depth to groundwater was 1.41 to 5.66 feet below ground surface. Groundwater flow direction was to the northwest on the west side and the southeast on the east side. The increase in contaminant concentrations appears to be related to the groundwater fluctuations at the site. When depth to groundwater is deeper the contamination is greater(as it was on this monitoring event), but when the groundwater rises the contamination concentrations are lower. Robert Weimer
9/6/2006 Update or Other Action ADEC approves reduction in groundwater monitoring to suspend sampling of MW-1, MW-4, MW-8, and MW-10. Robert Weimer
3/30/2007 Document, Report, or Work plan Review - other Reviewed the monitoring report for the September 15, 2006 groundwater sampling. Up to 0.28 mg/l DRO and 0.022 mg/l GRO in the groundwater. The depth to groundwater was 1.70 to 6.05 feet below ground surface. Groundwater flow direction was to the north on the north side and the southwest on the south side. The decrease in contaminant concentrations appears to be related to the groundwater fluctuations at the site. When depth to groundwater is shallower the contamination is lower (as it was on this monitoring event), but when the groundwater drops the contamination concentrations are generally higher. Robert Weimer
4/2/2007 Meeting or Teleconference Held Meeting with Chevron and its consultants to discuss numerous site. Denied request to supend sampling of monitoring well MW-3. Discussed that they needed to locate monitoring well MW-13 or install a replacement well at that location. We discussed that following the excavation work there still was a large amount of soil contamination remaining in-situ at the site that still needs to be addressed. Robert Weimer
12/7/2007 Document, Report, or Work plan Review - other Reviewed the monitoring report for the May 15, 2007 groundwater sampling. Up to 0.73 mg/l DRO, and non-detect GRO, benzene, EDB, and 1,2-DCA in the groundwater. The depth to groundwater was 2.52 to 9.08 feet below ground surface. Groundwater flow direction was to the north on the north side and the southwest on the south side. DRO contamination increased in 2 of the 3 monitoring wells sampled. Robert Weimer
1/25/2008 Document, Report, or Work plan Review - other Reviewed the monitoring report for the August 8, 2007 groundwater sampling. Up to 4.8 mg/l DRO and 6.5 mg/l GRO in the groundwater. The depth to groundwater was 6.55 to 11.37 feet below ground surface. Groundwater flow direction was to the southwest. Groundwater contamination increased in all of the monitoring wells sampled. Robert Weimer
1/25/2008 Conceptual Site Model Submitted Reviewed submitted conceptual site model. Completed exposure pathways identified were incidental soil ingestion, ingestion of groundwater, inhalation of outdoor air, and inhalation of indoor air. Robert Weimer
3/5/2008 Meeting or Teleconference Held Meeting with Chevron and their consultants. Chevron to conduct and indoor air evaluation for this site. They will evaluate corrective action options for this site and submit a corrective action plan in the future. Robert Weimer
5/15/2008 Exposure Tracking Model Ranking Site ranked on the new Exposure Tracking Model (ETM). The ETM is a new site ranking system that looks at, based on available data, the potential exposure pathways for the contamination remaining at the site. Robert Weimer
5/27/2008 Site Characterization Workplan Approved ADEC conditionally approves release investigation workplan that proposes drilling 6 soil borings and installing a replacement monitoring well (MW-13R). Robert Weimer
6/17/2008 Site Visit At the request of the ADEC project manager the quality assurance officer was onsite on June 17, 2008 to observe groundwater sampling by CRA consulting. No deviaitons from the work plan were noted while onsite. Brenton Porter
8/4/2008 Offsite Soil or Groundwater Disposal Approved ADEC approves thermal treatment of 3 drum of contaminated soil, and treatment of 1 drum of contaminated purge water. Robert Weimer
9/25/2008 Offsite Soil or Groundwater Disposal Approved ADEC approves treatment of contaminated purge water. Robert Weimer
1/21/2009 Document, Report, or Work plan Review - other Reviewed subsurface investigation and well installation report. On June 2, 2008 six soil borings were drilled and a replacement monitoring well was installed (MW-14). Up to 2.2 mg/kg benzene, 3,800 mg/kg GRO, and 4,000 mg/kg DRO was found in the soil areas sampled. Because of lab QA/QC problems the benzene detection limit exceeded cleanup levels in 4 samples and the DRO results may be biased low. Groundwater was encountered between 4.5 and 11 feet below ground surface in the soil borings, and 8 feet below ground surface in monitoring well MW-14. Soil sample CB6-5.0 is biased low due to elevated temperature in the cooler. Robert Weimer
1/22/2009 Document, Report, or Work plan Review - other Reviewed the monitoring report for the June 17, 2008 groundwater sampling. Up to 29 mg/l DRO, 40 mg/l GRO, and 0.07 ug/l benzene in the groundwater. The depth to groundwater was 4.88 to 11.72 feet below ground surface. Groundwater flow direction was to the north on the north side, west on the west side, and southeast on the southeast side. DRO contamination increased in 5 of the 8 monitoring wells sampled. Robert Weimer
2/25/2009 Meeting or Teleconference Held Meeting with Chevron and their consultants. They are to conduct an evaluation of indoor air pathway at this site. Chevron will look at the installation at monitoring wells downgradient of monitoring well MW-3. Chevron will also check the status of the replacement drinking water well. Chevron plan to have their consultant collect monitoried natural attentuation data in 2009. ADEC may request active remediation of this site after consultantion with land owner. Robert Weimer
4/9/2009 Document, Report, or Work plan Review - other Reviewed the monitoring report for the August 29, 2008 groundwater sampling. Up to 25 mg/l DRO and 14 mg/l GRO in the groundwater. The depth to groundwater was 6.39 to 11.77 feet below ground surface. Groundwater flow direction was to north west on the west and north west side, and east on the east side. Contamination increased in 5 of the 8 monitoring wells sampled. Robert Weimer
4/15/2009 Meeting or Teleconference Held Meeting with property owner regarding the progress of the cleanup on this site. He is requesting timely treatment of his property. Based on current groundwater contamination tends it does not appear that natural attenuation will be able to remediate the site in a timely matter that is compatible with the property owners planned use of their property. The property owner confirmed that the replacement drinking water well has not been used yet, but they plan to in the future. The property owner requests that the drinking water well be sampled for contamination. Robert Weimer
4/27/2009 Update or Other Action ADEC approves request to transport one drum of monitoring well purge water to 1441 C Street for secure storage. Robert Weimer
6/18/2009 Offsite Soil or Groundwater Disposal Approved ADEC approves request for treatment of one drum of monitoring well purge water. Robert Weimer
7/1/2009 Document, Report, or Work plan Review - other ADEC approves workplan for the installation and sampling of two additional monitoring wells downgradient to monitoring well MW-3. Robert Weimer
7/1/2009 Update or Other Action ADEC letter requests that the RP submit by August 15, 2009 a corrective action workplan for the active remediation of the remaining soil and groundwater contamination at this site. ADEC also requests that the replacement drinking water well be sampled for BTEX (by method 524.2), GRO, DRO, and RRO during future groundwater monitoring events. Robert Weimer
7/28/2009 Meeting or Teleconference Held Talked with RP's consultant. They will be contacting the property owner to get access to the replacement drinking water well. They also plan to request an extension to October 1, 2009 to submit a corrective action plan for the active remediation of the remaining contamination at this site. We discussed that based on recent trends and remaining concentrations, natural attenuation alone would not be able to remediate this site in a timely fashion. Robert Weimer
8/10/2009 Update or Other Action ADEC approves request for extension to November 30, 2009 to submit corrective action plan. Robert Weimer
8/20/2009 Offsite Soil or Groundwater Disposal Approved ADEC approves request for thermal treatment of 2 drums of contaminated soil generated during the July 2009 Subsurface Investigation. Robert Weimer
10/20/2009 Document, Report, or Work plan Review - other Reviewed the monitoring report for the May 13, 2009 groundwater sampling. Up to 7.6 mg/l DRO, 45 mg/l GRO, and 58 ug/l benzene in the groundwater. The depth to groundwater was 4.00 to 9.13 feet below ground surface. Groundwater flow direction was to west on the west side, and east on the east side. Contamination increased in 4 of the 8 monitoring wells sampled. BTEX and GRO results may be biased low because analysis was outside of holding times. Robert Weimer
10/26/2009 Offsite Soil or Groundwater Disposal Approved ADEC approves request for treatment of two drums of monitoring well purge water. Robert Weimer
2/3/2010 Document, Report, or Work plan Review - other Reviewed subsurface investigation report. On July 16, 2009 two additional monitoring wells were installed to the north by north west and to the northwest of monitoring well MW-3. Soil samples were collected from each boring at 5 feet below ground surface. Up to 0.02 mg/kg benzene and 57 mg/kg RRO in the soil samples collected. The GRO and DRO samples were non-detect. Groundwater was encountered at 7.80 to 8.20 feet below ground surface. Robert Weimer
2/3/2010 Update or Other Action RP's consultant provided a list of 3 proposed remedial alternatives to address the remaining contamination at this site. They were Dissolved Oxygen Enhancement, In-Situ Chemical Oxidation, and Excavation. They plan to discuss these in the March 10, 2010 Chevron/Texaco sites meeting and provide a corrective action plan by April 15, 2010, and to conduct the work in 2010. Robert Weimer
2/4/2010 Document, Report, or Work plan Review - other Reviewed the monitoring report for the September 9, 2009 groundwater sampling. Up to 84 mg/l DRO and 56 mg/l GRO in the groundwater. The depth to groundwater was 4.73 to 10.28 feet below ground surface. Groundwater flow direction was generally to the north. Contamination increased in 5 of the 10 monitoring wells sampled. Sample results in monitoring well MW-9 may be biased low because it was not preserved with a pH <2. The on-site replacement drinking water well was not sampled as requested in the ADEC letter of July 2, 2009. Robert Weimer
3/4/2010 Meeting or Teleconference Held Meeting with property owner regarding the progress of the cleanup on this site and the three remedial alternatives proposed by Chevron's consultant in their 11/11/09 letter. He is requesting timely treatment of his property. The property owner also requests that the drinking water well be sampled for contamination. Robert Weimer
3/16/2010 Meeting or Teleconference Held Meeting with Chevron and their consultants on 3/10/10. Monitoring wells MW13 and MW14 are to be sampled for PAHs the next monitoring event. Chevron will submit a work plan active remediation of the remaining contamination at the site by April 15, 2010. Chevron will get access to the replacement drinking water well point that has a welded cap over it to collected the requested drinking water well sample. We discussed that groundwater samples for volatiles should not be collected with bailers or peristaltic pumps due to the loss of volatiles, Chevron is to provide a work plan specifying how groundwater samples will be collected in the future. Robert Weimer
5/12/2010 Meeting or Teleconference Held Teleconference with DEC, Chevron, and their consultant (CRA) to discuss the April 15, 2010 Corrective Action Plan. The plan evaluated Dissolved Oxygen Enhancement (DOE), In-Situ Chemical Oxidation (ISCO), Excavation, and Monitoried Natural Attenuation (MNA). We discussed that the estimated treatment time for DOE (26 years) and MNA (50 years) was too long. We discussed that the estimated 22,000 to 44,000 tons of soil that would need to be treated seemed much higher than the site data indicated (around 3,000 tons) so the estminated costs for excavation appears be too high. CRA will provide copies of their cost calcuations for review. We discussed that in the almost 10 years since the last site excavation work was done (2000), the groundwater concentrations have shown little natural attenuation. Robert Weimer
5/20/2010 Update or Other Action Approved, until further notice, no-purge groundwater sampling at this site. Robert Weimer
5/27/2010 Document, Report, or Work plan Review - other ADEC approved transport to 1441 C Street secure storage area of 1 drum of purge water generated during the 1st semiannual groundwater sampling event in June 2010. Robert Weimer
8/27/2010 Offsite Soil or Groundwater Disposal Approved ADEC approves treatment of contaminated purge water. Robert Weimer
2/22/2011 Update or Other Action Groundwater monitoring reports note that monitoring well MW-14 was not sampled due the presence of product on the groundwater. They measured 1.5 inches of product on 6/2/10 (groundwater at 6.9 feet below ground surface) and 3.36 inches of product on 8/3/10 (groundwater at 7.85 feet below ground surface). Chevron needs to submit a work plan for defining the extent of the product on the groundwater and recovery of the product. Robert Weimer
3/2/2011 Update or Other Action ADEC approves temporary storage of any purgewater generated in 2011 at the secure area at 1441 C Street. Robert Weimer
3/16/2011 Document, Report, or Work plan Review - other Reviewed the monitoring report for the June 2, 2010 groundwater sampling. Up to 1.5 mg/l DRO, 0.18 mg/l GRO, and 0.9 ug/l benzene in the groundwater. The depth to groundwater was 4.06 to 8.35 feet below ground surface. Groundwater flow direction was to the north by northwest. Contamination increased in 2 of the 8 monitoring wells sampled. 0.125 feet of product was measured in monitoring well MW-14. The on-site replacement drinking water well was not sampled as requested in the ADEC letter of July 2, 2009. Robert Weimer
3/21/2011 Document, Report, or Work plan Review - other Reviewed the monitoring report for the August 3, 2010 groundwater sampling. Up to 4.4 mg/l DRO and 11 mg/l GRO in the groundwater. The depth to groundwater was 5.11 to 10.22 feet below ground surface. Groundwater flow direction was to the northwest. Contamination increased in 3 of the 8 monitoring wells sampled. 0.28 feet of product was measured in monitoring well MW-14. The on-site replacement drinking water well was not sampled as requested in the ADEC letter of July 2, 2009. Robert Weimer
7/22/2011 Offsite Soil or Groundwater Disposal Approved ADEC approves treatment of contaminated purge water. Robert Weimer
9/8/2011 Document, Report, or Work plan Review - other ADEC approves temporary storage of drill cuttings and decon water at the secure area at 1441 C Street. Robert Weimer
9/8/2011 Site Characterization Workplan Approved ADEC reviews and approves soil vapor assessment work plan. The work plan proposes to install a soil vapor well and collect air samples to help assess the soil vapor concentrations near the current on-property building. Robert Weimer
9/8/2011 Update or Other Action ADEC again requests that the replacement drinking water well be sampled for BTEX (by method 524.2), GRO, DRO, and RRO during the next groundwater monitoring event at the site this fall. Robert Weimer
9/21/2011 Update or Other Action Update from CRA on recent site work. Vapor probe was installed at 2.5 ft below ground surface (bgs) with depth to groundwater at 3 ft bgs. They could not collect vapor samples because heavy rains overnight had raised groundwater and submerged the screened interval in the probe. CRA intends to collect the vapor sample and the drinking water well sample in October or November 2011. Robert Weimer
10/26/2011 Offsite Soil or Groundwater Disposal Approved ADEC approves treatment of contaminated purge water. Robert Weimer
11/9/2011 Meeting or Teleconference Held Meeting with RP's consultant CRA. The recently installed vapor probe has been submerged. They plan to sample when the groundwater drops in the winter. Robert Weimer
2/24/2012 Document, Report, or Work plan Review - other Reviewed the monitoring report for the May 17, 2011 groundwater sampling. Up to 130 mg/l DRO and 17 mg/l GRO in the groundwater. The depth to groundwater was 4.63 to 9.30 feet below ground surface. Groundwater flow direction was to the north by northeast. Contamination increased in 3 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The on-site replacement drinking water well was not sampled as requested in the ADEC letter of July 2, 2009. Robert Weimer
2/27/2012 Update or Other Action Since no product was measured in any of the site monitoring wells in 2011 ADEC approves request to submit a LNAPL Abatement Workplan when/if product is found in the future. Robert Weimer
3/7/2012 Meeting or Teleconference Held Meeting with Chevron and their consultants on 2/28/12. Chevron is to submit a corrective action plan for the timely cleanup of the site. They are to continue semi-annual groundwater and drinking water well monitoring and collect soil gas samples. They are to find the drinking water well log, and to conduct a pump test on the drinking water well to see if it causes any draw down in the site monitoring wells. The ADEC is to contact the property owner for input regarding timely cleanup of the property. Robert Weimer
8/20/2012 Offsite Soil or Groundwater Disposal Approved ADEC approves offsite treatment of contaminated purge water. Robert Weimer
10/23/2012 Document, Report, or Work plan Review - other Reviewed the monitoring report for the September 14, 2011 groundwater sampling. Up to 150 mg/l DRO, 3.2 mg/l GRO, and 6.2 ug/l benzene in the groundwater. The depth to groundwater was 1.56 to 7.40 feet below ground surface. Groundwater flow direction was to the northwest. Contamination increased in 3 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The on-site replacement drinking water well was sampled and it was non-detect for DRO, GRO, and BTEX. The depth to groundwater in the drinking water well was 9.88 feet below ground surface. The base of the well was measured at 78 feet below ground surface. When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. Robert Weimer
10/23/2012 Update or Other Action Update from RP's consultant. The pump test work plan is to be submitted by November 15, 2012 for a pump test to be conducted on the drinking water well in 2013. The soil gas probe CRA installed in 2011 at 2.5 fbg has been submerged in water since its installation. Soil gas sampling has not been possible due to the submerged probe. CRA is currently evaluating alternative options for a vapor assessment. Robert Weimer
10/25/2012 Document, Report, or Work plan Review - other Reviewed the monitoring report for the May 31, 2012 groundwater sampling. Up to 38 mg/l DRO, 14 mg/l GRO, and 59 ug/l benzene in the groundwater. Some of the results may be biased low due to some of the water samples not being preserved properly in the field. The depth to groundwater was 2.51 to 9.39 feet below ground surface. Groundwater flow direction was to the northwest. Contamination increased in 9 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The on-site replacement drinking water well was sampled and had 0.32 mg/l DRO, 0.1 ug/l toluene, and non-detect for benzene and GRO. The depth to groundwater in the drinking water well was 9.39 feet below ground surface. The base of the well was measured at 78 feet below ground surface (bgs). When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. Robert Weimer
10/31/2012 Meeting or Teleconference Held Meeting with property owner regarding the progress of the cleanup on this site and other site work. He is requesting timely treatment of his property, vapor monitoring, and drinking water well pump testing. Robert Weimer
11/8/2012 Update or Other Action Chevron to contact the property owner within the next two weeks to initiate discussions regarding alternatives for the site. These alternatives could involve an agreement with property owner to compensate him while the site is undergoing monitoring or remediation. Robert Weimer
11/13/2012 Meeting or Teleconference Held Alexis Fischer of Chevron talked to Robert Hall (property owner) today to discuss his concerns and alternatives for the Portage property. Chevron will be following up with Robert Hall after Chevron has some internal discussions and follow up on some issues that Robert brought up during the call. Chevron is hopeful that they can come to a favorable resolution of Robert Hall’s concerns. Chevron will keep DEC informed going forward. Robert Weimer
2/27/2013 Meeting or Teleconference Held Meeting with Chevron and their consultants on 2/26/13. Chevron proposes to continue to conduct semi-annual groundwater monitoring to monitor for natural attenuation and trends, drinking water well sampling, and conduct pump test on drinking water well to see if it is drawing water from the shallow contaminated aquifer. Chevron said they are still in discussions with the property owner regarding the rate of the cleanup of this site. The next groundwater sampling event they will sample both using no purge and purge help evaluate that the past no purge results were providing comparable data. We discussed that all semi-annual monitoring events need to be at least 120 days apart. We also discuss that in 2013 the property may be used as a camp with an on-site septic system or holding tank. Robert Weimer
3/26/2013 Update or Other Action ADEC conditionally approves the use of a portable activated carbon (gac) filter system for this site to treat water generated during groundwater monitoring. The storage of water at the site or the secure storage area at 1441 C Street is also approved. Robert Weimer
3/27/2013 Update or Other Action ADEC drinking water program forwarded a copy of the replacement drinking water well log to DNR so it can be included in the on-line well log tracking system (WELTS). The driller of the well in 2001 had not submited a copy of the well log to DNR as required. Robert Weimer
2/4/2014 Document, Report, or Work plan Review - other Reviewed the monitoring report for the May 18-19, 2013 groundwater sampling. Up to 3.4 mg/l DRO, 2.2 mg/l GRO, and non-detect (<0.24 ug/l) benzene in the groundwater. The depth to groundwater was 2.02 to 9.78 feet below ground surface. Groundwater flow direction was to the northwest. Contamination increased in 2 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The on-site replacement drinking water well was sampled and it had 0.12 ug/l toluene, and non-detect GRO, DRO, and benzene. The depth to groundwater in the drinking water well was 9.78 feet below ground surface. The base of the well was measured at 78 feet below ground surface (bgs). When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. Samples were collect by both no-purge (Hydrasleeve) and purge (bladder pump) methods. The sampling interval for the bladder pump was not documented in the field notes. The hydrasleeve sampling was from the top of the water column. Robert Weimer
2/27/2014 Meeting or Teleconference Held Meeting with Chevron and their consultants on 2/27/2014. They plan to continue semi-annual groundwater and drinking water well monitoring. Because of problems with last year’s purge/no-purge sampling the next groundwater sampling event they will sample both using no purge and purge help evaluate that the past no purge results were providing comparable data or they will switch to no purge for future sampling events. We discussed that the groundwater samples needs to be collected as close as possible to the soil/water interface, with the pump intake within a foot of the soil/water interface at the time of the sampling. They still need a frozen and non-frozen ground soil gas sampling events to help evaluated the vapor intrusion pathway when the groundwater drops enough to take a vapor sample. In the future they will need to evaluate for a diving plume on the monitoring wells far from the release point. The consultant will make sure that their site reports are complete in accordance with DEC’s 9/23/2009 Site Characterization Work Plan and Reporting Guidance for Investigation of Contaminated Sites. Chevron is currently in discussions with the property owner regarding the rate of cleanup of the site. The requested pump test is on hold pending the use or abandonment of the on-property drinking water well. If not resolved the pump test will need to be conducted before the end of 2014. Robert Weimer
9/5/2014 Document, Report, or Work plan Review - other Reviewed the monitoring report for the September 15, 2013 groundwater sampling. Up to 13.2 mg/l DRO, 0.45 mg/l GRO, and non-detect (<0.24 ug/l) benzene in the groundwater. The depth to groundwater was 2.56 to 10.01 feet below ground surface. Groundwater flow direction was to the northwest. Contamination increased in 4 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The on-site replacement drinking water well was sampled and had 0.44 mg/l DRO, and non-detect GRO and BTEX. The depth to groundwater in the drinking water well was 10.01 feet below ground surface. The base of the well was measured at 77.43 feet below ground surface (bgs). When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. Samples were collect by no-purge (Hydrasleeve). The hydrasleeve sampling was from the top of the water column. Robert Weimer
11/10/2014 Update or Other Action Update from Chevron's consultant CRA. The report for the 1st semi-annual 2014 groundwater monitoring event should be submitted soon. The 2nd semi-annual 2014 groundwater monitoring event was conducted on October 2, 2014. They did not encounter any measureable product during either monitoring event. Discussions between the property owner and Chevron continue. Currently they have not completed the soil gas sampling or the groundwater pump test. Robert Weimer
11/10/2014 Meeting or Teleconference Held Meeting with property owner to discuss current site status. Discussions between the property owner and Chevron continue regarding the sale of the property. Robert Weimer
2/23/2015 Document, Report, or Work plan Review - other Reviewed the monitoring report for the May 3, 2014 groundwater sampling. Up to 261 mg/l DRO, 11.2 mg/l GRO, and 3.4 ug/l benzene in the groundwater. The depth to groundwater was 4.61 to 10.48 feet below ground surface. Groundwater flow direction was to the north. Contamination increased in 7 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The on-site replacement drinking water well was sampled and had 0.63 mg/l RRO, and non-detect for BTEX, GRO, and DRO. The depth to groundwater in the drinking water well was 10.48 feet below ground surface. The base of the well was measured at 77.43 feet below ground surface (bgs). When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. Samples were collect by no-purge (hydrasleeve), with no-purge DRO samples collected with a Teflon bailer, and purge (bladder pump). The hydrasleeve sampling was from the top of the water column. Because the intake for the purge sampling for four of the monitoring wells (MW-7, MW-9, MW-15, and MW-16) was not at the soil/water interface was required (it was up to 1.93 feet below the soil/water interface) the results for those monitoring wells is considered biased low. The groundwater sample collected from monitoring well MW-14 which has show measureable product in the past (2010) had 261 mg/l DRO for no-purge vs. 11.7 mg/l for purge, and 2.8 mg/l GRO for no-purge vs. 11.2 mg/l for purge. Robert Weimer
6/11/2015 Document, Report, or Work plan Review - other Reviewed the monitoring report for the October 2, 2014 groundwater sampling. Up to 2.2 mg/l DRO, 3.1 mg/l GRO, and 1.8 ug/l benzene in the groundwater. The depth to groundwater was 3.9 to 11.02 feet below ground surface. Groundwater flow direction was to the north. Contamination increased in 4 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The on-site replacement drinking water well was sampled and had 0.11 mg/l DRO, non-detect (<0.05 mg/l) GRO, non-detect (<0.3 mg/l) RRO, and non-detect (<0.073 ug/l) benzene. The depth to groundwater in the drinking water well was 11.02 feet below ground surface. The base of the well was measured at 77.43 feet below ground surface (bgs). When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. The samples were collected by and after purging with a bladder pump. Because the intake for the purge sampling for 7 of the monitoring wells (MW-9, MW-11, MW-12, MW-13, MW-14, MW-15, and MW-16) was not at the soil/water interface was required (it was up to 2.52 feet below the soil/water interface) the results for those monitoring wells is considered biased low. The sample collected from the drinking water well is also considered biased low since the intake was not at the top of the water column (it was 1.98 feet below the soil/water interface) and only 1.3% of the well volume was purged prior to sampling. Robert Weimer
5/2/2016 Document, Report, or Work plan Review - other October 2, 2014 groundwater sampling. Up to 0.66 mg/l DRO, 0.15 mg/l GRO, and non-detect benzene in the groundwater. The depth to groundwater was 3.72 to 10.45 feet below ground surface. Groundwater flow direction was to the north. Contamination increased in 4 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The on-site replacement drinking water well was sampled and had non-detect DRO, GRO, and BTEX. The depth to groundwater in the drinking water well was 10.45 feet below ground surface. The base of the well was measured at 77.43 feet below ground surface (bgs). When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. The samples were collected by and after purging with a bladder pump in monitoring wells MW-11, MW-13, and MW-14. The rest of the wells were sampled with a Hydrasleeve without purging. All of the samples were collected at the top of the water column as required. Robert Weimer
10/13/2016 Document, Report, or Work plan Review - other October 15, 2015 groundwater sampling. Up to 0.70 mg/l DRO, 0.014 mg/l GRO, and non-detect benzene in the groundwater. The depth to groundwater was 2.99 to 9.06 feet below ground surface. Groundwater flow direction was to the north by northwest. Contamination increased in 2 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The on-site replacement drinking water well was sampled and had non-detect DRO, GRO, and BTEX. The depth to groundwater in the drinking water well was 9.06 feet below ground surface. The base of the well was measured at 77.43 feet below ground surface (bgs). When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. The samples were collected by and after purging with a bladder pump in monitoring wells MW-11, MW-13, and MW-14. The rest of the wells were sampled with a Hydrasleeve without purging. All of the samples were collected at the top of the water column as required. Robert Weimer
1/23/2017 Document, Report, or Work plan Review - other May 20, 2016 groundwater sampling. Up to 1.3 mg/l DRO, 0.61 mg/l GRO, and 0.6 ug/l benzene in the groundwater. The depth to groundwater was 3.96 to 8.28 feet below ground surface. Groundwater flow direction was to the north by northwest. Contamination increased in 8 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The on-site replacement drinking water well was sampled with Hydrasleeve without purging and had non-detect RRO, DRO, GRO, and BTEX. Because the depth to groundwater in the drinking water well was not measured it was not documented that the sampling was conducted at the correct sampling interval, so those results may be biased low. The base of the well was measured at 77.43 feet below ground surface (bgs). When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. The samples were collected by and after purging with a bladder pump in monitoring wells MW-11, MW-13, and MW-14. The rest of the wells were sampled with a Hydrasleeve without purging. Because the Hydrasleeve samples were not collected at the top of the water column as required those results may be biased low. Robert Weimer
10/3/2017 Document, Report, or Work plan Review - other September 29-30, 2016 groundwater sampling. Up to 0.39 mg/l DRO, 0.84 mg/l GRO, and non-detect benzene in the groundwater. The depth to groundwater was 3.29 to 8.01 feet below ground surface. Groundwater flow direction was to the north by northwest. Contamination increased in 3 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The on-site replacement drinking water well was sampled with Hydrasleeve without purging and had 0.077 mg/l DRO, non-detect RRO, GRO, and BTEX. Because the depth to groundwater in the drinking water well was not measured it was not documented that the sampling was conducted at the correct sampling interval, so those results may be biased low. The base of the well was measured at 77.43 feet below ground surface (bgs). When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. The samples were collected by and after purging with a bladder pump at the top foot of the water column as required. Robert Weimer
11/21/2017 Document, Report, or Work plan Review - other May 10, 2017 groundwater sampling. Up to 0.19 mg/l DRO, non-detect GRO, and non-detect benzene in the groundwater. Full VOCs analysis by method 8260 was run and all of the samples were non-detect. The depth to groundwater was 2.79 to 7.38 feet below ground surface. Groundwater flow direction was to the north by northwest. Contamination increased in 1 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The on-site replacement drinking water well was sampled with Hydrasleeve without purging and had 0.37 mg/l DRO, 0.02 ug/l Toluene, and non-detect RRO, GRO, and benzene. The base of the well was measured at 77.43 feet below ground surface (bgs). When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. The samples were collected by and after purging with a bladder pump in monitoring wells. Robert Weimer
1/31/2018 Document, Report, or Work plan Review - other October 9, 2017 groundwater sampling. Up to 0.13 mg/l DRO, non-detect GRO, and non-detect benzene in the groundwater. Full VOCs analysis by method 8260 was run and all of the samples were non-detect. The depth to groundwater was 2.20 to 7.07 feet below ground surface. Groundwater flow direction was to the north by northwest. Contamination increased in 0 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The on-site replacement drinking water well was sampled with Hydrasleeve without purging and it was non-detect for DRO, RRO, GRO, and BTEX. The base of the well was measured at 77.43 feet below ground surface (bgs). When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. The samples were collected by and after purging with a bladder pump in monitoring wells. Robert Weimer
1/9/2019 Document, Report, or Work plan Review - other June 11-12, 2018 groundwater sampling. Up to 6.8 mg/l DRO, 20 mg/l GRO, 1,000 ug/l ethylbenzene, 4,300 ug/l xylenes, 77 ug/l toluene, and 4 ug/l benzene in the groundwater. Monitoring well MW-11 (the well with the highest concentration) had the highest DRO concentration since 2008 and the highest GRO, ethylbenzene, and xylenes concentrations since the monitoring well was installed in 2001. Full VOCs analysis by method 8260 was run and besides BTEX the other detectable VOC compounds were below Table C cleanup levels. The depth to groundwater was 4.36 to 10.43 feet below ground surface. Groundwater flow direction was to the north by northwest. Contamination increased in 9 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The on-site replacement drinking water well was sampled with Hydrasleeve without purging and it was non-detect for DRO, RRO, GRO, and BTEX. The base of the well was measured at 77.43 feet below ground surface (bgs). When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. The samples from the monitoring wells were collected after purging using a bladder pump from the top foot of the water column. Robert Weimer
1/30/2019 Exposure Tracking Model Ranking A new updated ranking with ETM has been completed for source area 72985 1993 Contamination. Robert Weimer
4/2/2019 Document, Report, or Work plan Review - other September 10, 2018 groundwater sampling. Up to 3.5 mg/l DRO, 3.0 mg/l GRO, 68 ug/l ethylbenzene, 320 ug/l xylenes, 190 ug/l toluene, and 0.8 ug/l benzene in the groundwater. Full VOCs analysis by method 8260 was run and besides BTEX the other detectable VOC compounds were below Table C cleanup levels. The depth to groundwater was 5.61 to 11.16 feet below ground surface. Groundwater flow direction was to the northeast. Contamination increased in 4 of the 10 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The samples from the monitoring wells were collected after purging using a bladder pump from the top foot of the water column. The on-site replacement drinking water well was sampled with Hydrasleeve without purging and it was non-detect for DRO, RRO, GRO, and BTEX, these results of the sampling may be biased low since the sample interval was not documented. The base of the well was measured at 77.43 feet below ground surface (bgs). When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. Robert Weimer
8/29/2019 Meeting or Teleconference Held Meeting with property owner. DOT is looking a purchasing an easement, portion of the property, or the whole property. From the DOT design it looks like the road may only cover the furthest downgradient monitoring wells (MW-15 and MW-16) which would need to be decommissioned by Chevron. The road work may also cover closer monitoring wells (MW-3, MW-6, and MW-7) that would need to be decommissioned and replaced by Chevron. The property owner is still interested in developing the property and getting the active remediation of the site conducted. Robert Weimer
9/23/2019 Update or Other Action ADEC requests for this site that the monitoring wells are purged prior to sampling, and that the intake of the bladder pump/in-well pump be documented in the field notes to be within the top foot of the water column at the time of the sampling. Also VOC sampling needs to include the full 8260 VOC list including naphthalene. Robert Weimer
12/12/2019 Offsite Soil or Groundwater Disposal Approved ADEC approves request for treatment at NRC of 5 gallons of purge water generated during the 5/6/2019 groundwater monitoring event Robert Weimer
1/16/2020 Document, Report, or Work plan Review - other May 11, 2019 groundwater sampling. Up to 2.0 mg/l DRO, 12.0 mg/l GRO, 3 ug/l benzene, 41 ug/l toluene, 450 ug/l ethylbenzene, 1,900 ug/l xylenes, and 2.1 mg/l RRO in the groundwater. The depth to groundwater was 4.41 to 10.97 feet below ground surface. Groundwater flow direction was to the northwest. Contamination increased in 3 of the 9 monitoring wells sampled. No product was measured in any monitoring wells this monitoring event. The samples from the monitoring wells were collected after purging using a bladder pump. The results may be biased low in 7 of the 9 monitoring wells sampled because they were not document as being collected from the top foot of the water column (monitoring well 3, 7, 9 were too deep, and 11, 12, 14, 15 were not documented). The on-site replacement drinking water well was sampled with a bladder pump after purging and it was non-detect for DRO, RRO, GRO, and BTEX, these results of the sampling may be biased low since the sample interval was not within the top foot of the screened interval. The base of the well was measured at 80.75 feet below ground surface (bgs). When the well was installed in 2001 it was cased to 100 feet bgs and perforated at 40 to 43 feet bgs. For this monitoring event there was no PAH analysis and only BTEX was reported for the VOC analysis. Robert Weimer
3/12/2020 Update or Other Action ADEC requests for this site that the monitoring wells are purged prior to sampling, and that the intake of the bladder pump/in-well pump be documented in the field notes to be within the top foot of the water column at the time of the sampling. Also all BTEX and VOC sampling needs to include the full 8260 VOC list including naphthalene. ADEC is also requesting that all reports be submitted within 60 days of the sampling and the groundwater monitoring figure include a diagram showing historic groundwater flow directions. For the on-site replacement drinking water well the intake of the pump needs to be within the top foot of the perforated interval (40 to 43 feet below ground surface) in the well, which means the intake should be between 40 to 41 feet below ground surface. Robert Weimer
3/17/2020 Document, Report, or Work plan Review - other DEC reviewed 2020 groundwater sampling plan and provided the following comments: For all future monitoring events please make sure that the field notes document the measurement of the pump intake that is within the top foot of the water column at the time of the sampling unless the top of the well screened interval is deeper, then in that case from the top foot of that screened interval. For all future monitoring events any monitoring well where BTEX or HVOC sampling is proposed it needs to be the full VOC (method 8260) list, including naphthalene. The field QC samples are per day of sampling at a site. For all future monitoring events all reports be submitted within 60 days of the sampling and the groundwater monitoring figure include a diagram showing historic groundwater flow directions. For all future monitoring events if a monitoring well is low yield and purges dry then a sample will still need to be collected that monitoring event once the monitoring well has recharged to approximately 80% of its pre-purge volume. If it has not returned to 80% of its pre-purged volume during that sampling day DEC requests that you return to the site early the next day to attempt to collect the water sample. DEC also requested for the on-site replacement drinking water well the intake for the pump needs to be in the top foot of the perforated interval (40 to 43 feet below ground surface in the well. Robert Weimer
1/15/2021 Meeting or Teleconference Held DEC staff met with Chevron Environmental Management Company (CEMC) and Arcadis to discuss Chevron sites located in Alaska during the Annual Portfolio Meeting on January 14th and 15th, 2021. Rebekah Reams
7/9/2021 Document, Report, or Work plan Review - other 2020 First Semi-Annual Groundwater Monitoring event was conducted on April 20th and 21st, 2020. Groundwater samples were collected from monitoring wells MW-3, MW-6, MW-7, MW-9, MW-11 through MW-16, and drinking water well DWW-1. Samples were submitted to the analytical laboratory for GRO, DRO, RRO, and VOCs. Groundwater flow direction was to the northwest and depth to groundwater was 1.71 to 9.55 feet below ground surface. Rebekah Reams
7/12/2021 Document, Report, or Work plan Review - other 2020 Second Semi-Annual Groundwater Monitoring event was conducted on October 21st and 22nd, 2020. Groundwater samples were collected from monitoring wells MW-3, MW-6 through MW-16, and DWW-1. Samples were submitted to the analytical laboratory for GRO, DRO, RRO, and VOCs. Groundwater flow direction was to the west-northwest and depth to groundwater was 3.41 to 9.98 feet below ground surface. Rebekah Reams
7/13/2021 Document, Report, or Work plan Review - other 2021 First Semi-Annual Groundwater Monitoring event was conducted on April 26th and 27th, 2021. Groundwater samples were collected from monitoring wells MW-3, MW-6, MW-7, MW-9, MW-11 through MW-16, and drinking water well DWW-1. Samples were submitted to the analytical laboratory for GRO, DRO, RRO, and VOCs. Groundwater flow direction was to the west-northwest and depth to groundwater was 3.45 to 9.37 feet below ground surface. Rebekah Reams
7/13/2021 Update or Other Action Monitoring wells MW-15 and MW-16 were decommissioning in support of road construction activities near the site. Rebekah Reams
4/7/2022 Document, Report, or Work plan Review - other 2021 Second Semi-Annual Groundwater Monitoring event was conducted on September 13, 2021. Groundwater samples were collected from monitoring wells MW-3, MW-7, MW-11, MW-12, and MW-14 through MW-16 and from drinking water well DWW-1. Monitoring wells MW- 6, MW-9, and MW-13 could not be located. MW-15 and MW-16 were removed due to construction. Samples were submitted to the analytical laboratory for GRO, DRO, RRO, and VOCs. Groundwater flow direction was to the northwest and depth to groundwater was 6.85 to 10.95 feet below ground surface. Rebekah Reams
4/27/2022 Meeting or Teleconference Held DEC met with Chevron and Arcadis personnel to discuss the recommended path forward at this site. Rebekah Reams
7/22/2022 Long Term Monitoring Workplan or Report Review 2022 First Semi-Annual Groundwater Monitoring event was conducted on May 9, 2022. Groundwater samples were collected from monitoring wells MW-3, MW-7, MW-12, and from drinking water well DWW-1. MW-1 and MW-8 were not sampled. MW-6 was destroyed from construction. MW-9, MW-10, MW-11, MW-13, and MW-14 were unable to be located. MW-15 and MW-16 were removed due to construction. Samples were submitted to the analytical laboratory for GRO, DRO, RRO, and VOCs. Groundwater flow direction was to the east and depth to groundwater was 4.02 to 10.85 feet below ground surface. Rebekah Reams
9/29/2022 Document, Report, or Work plan Review - other ADEC provided comments on the Treatment of Purge Water Utilizing Granular Activated Carbon (GAC) at Chevron Environmental Management Company Sites which includes standard operating procedures and breakthrough estimates proposed for use at this site. Rebekah Reams
11/4/2022 Document, Report, or Work plan Review - other DEC provided comments on the Conceptual Site Model Report which summarizes the site history, evaluates potential exposure pathways, identifies data gaps, and recommends next steps for the site. Remaining data gaps to be addressed at this site prior to closure include demonstrating a stable or decreasing trend in groundwater contaminant concentrations, evaluating additional Contaminants of Potential Concern (COPCs), and addressing Maximum Allowable Concentration (MAC) exceedances remaining at the site. Rebekah Reams
11/10/2022 Exposure Tracking Model Ranking A new updated ranking with ETM has been completed for source area 72985 1993 Contamination. Rebekah Reams
12/23/2022 Offsite Soil or Groundwater Disposal Approved DEC approved transport of one 55-gallon drum of purge water for offsite disposal Rebekah Reams
7/27/2023 Meeting or Teleconference Held Met with consultant to discuss proposed institutional controls and the path to site closure. ADEC highlighted the need for additional confirmation sampling of former maximum allowable concentration exceedances where site infrastructure allows, evaluation of additional COPCs, and the need to consider vapor intrusion potential for the buildings that have recently been constructed over areas with remaining contamination at the site. Once the proposed institutional controls have been shared with DOT, a meeting will be scheduled with all stakeholders to discuss the potential for closure with institutional controls. Rebekah Reams
11/7/2023 Document, Report, or Work plan Review - other 2023 Second Semi-Annual Groundwater Monitoring event was conducted on September 18, 2023. Groundwater samples were collected from monitoring wells MW-3 MW-7, MW-9, and from drinking water well DWW-1. Monitoring wells MW-10, MW-11, MW-12, MW-13, and MW-14 could not be located due to construction staging on site. Monitoring well MW-6 was not sampled due to casing and vault damage. Samples were submitted to the analytical laboratory for GRO, DRO, RRO, and VOCs. Groundwater flow direction was to the east and depth to groundwater was 1.36 to 9.06 feet below ground surface. All analytes were below cleanup levels during this sampling event. Rebekah Reams
4/23/2024 Meeting or Teleconference Held DEC met with the responsible party, environmental consultant, and landowner to discuss the path to site closure, anticipated land use, and the potential for applying an environmental covenant with land use controls to support site closure. This site is currently used as a road construction temporary project office and this use is anticipated to continue until November 1, 2024. Rebekah Reams
9/25/2024 Meeting or Teleconference Held ADEC staff met with Chevron and their consultant for an annual portfolio meeting to discuss site status, upcoming document submittals, pending reviews, and general updates for Chevron's contaminated sites throughout the state. Rebekah Reams
10/17/2024 Offsite Soil or Groundwater Disposal Approved ADEC approved transport of 55 gallons of purge water generated during 2024 groundwater monitoring events Rebekah Reams

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