| Action Date |
Action |
Description |
DEC Staff |
| 1/19/1989 |
Site Added to Database |
An unknown amount of Jet fuel leaked from two pin holes in the pipeline at this location. Leak detected during line pressure test. |
Former Staff |
| 7/2/1990 |
Update or Other Action |
To date 127.6 gallons of Jet A have been recovered from the recovery well. |
Robert Weimer |
| 4/24/1996 |
Site Ranked Using the AHRM |
Ranked by Shannon and Wilson. |
S&W |
| 12/8/1997 |
Site Ranked Using the AHRM |
Site reranked by staff. Changed Environmental/Recreation Area Value from 2 to 0. |
Bill Petrik |
| 12/10/1999 |
Update or Other Action |
Reviewed file to determine status and whether additional action is needed. CSRP will draft a letter requesting additional characterization. |
Eileen Olson |
| 1/28/2000 |
Meeting or Teleconference Held |
Met with Signature environmental representative to discuss site status and the need for characterization of groundwater and soil contamination. |
Eileen Olson |
| 9/6/2000 |
Site Characterization Workplan Approved |
Sent letter conditionally approving "Work Plan for Soil and Groundwater Sampling, 16th Avenue and C Street Pipeline Release." |
Eileen Olson |
| 1/8/2001 |
Update or Other Action |
Received "Report for Soil and Groundwater Sampling, 16th Avenue and C Street Pipeline Release" dated December 28, 2000. Up to 1,150 mg/l DRO, 66.8 mg/l GRO, and .109 mg/l benzene was found in the groundwater. Up to 2,300 mg/kg DRO and 0.115 mg/kg benzene was found in the soil. The report recommends monthly checks for product in the recovery well, installing additional groundwater monitoring wells to help define the extent of the groundwater contamination, and to collect upgradient soil data. |
Eileen Olson |
| 11/3/2004 |
Update or Other Action |
Formerly CS92.28
File number issued: 2100.38.439 |
Aggie Blandford |
| 2/17/2005 |
Update or Other Action |
Called RP's rep (LB) and discussed site status. She said that they have been checking for product, but no other work has been done. She will have her replacement submit by the end of March 2005 a workplan to install monitoring wells and collect soil and groundwater samples. |
Robert Weimer |
| 5/27/2005 |
Meeting or Teleconference Held |
Meeting to discuss future site work. To meet out at the site next week to discuss monitoring well locations. Recommend that monitoring wells be moved to the south and west.
Because of limited funding this year ASIG proposes to limit the work this year to the installation of 3 monitoring wells and groundwater sampling. They will submit a revised workplan for the installation of 3 monitoring wells. We discussed that they will need additional confirmation soil samples prior to closure of the site. We also discussed that additional release investigation and/or corrective action may be needed in the future. |
Robert Weimer |
| 6/9/2005 |
Meeting or Teleconference Held |
Meeting at the site to discuss location of monitoring wells. They are to install 2 just to the southwest of the middle and southern end of the trench, and two more monitoring wells in the trees about 30 feet southwest from the first two wells. The recovery well had a fuel odor. |
Robert Weimer |
| 7/8/2005 |
Update or Other Action |
ADEC approves workplan to install and sample 4 monitoring wells to help define the extent of the groundwater contamination. |
Robert Weimer |
| 9/14/2005 |
Update or Other Action |
Discussed site with ASIG. Reviewed site access documents for the downgradient church property. |
Robert Weimer |
| 9/15/2005 |
Meeting or Teleconference Held |
Meeting with downgradient church property owner to discuss site access for the placement of two monitoring wells on their property. |
Robert Weimer |
| 9/18/2006 |
Update or Other Action |
November 21, 2005 Groundwater Assessment Report. Two monitoring wells were installed on 9/29/05. Up to 10 ug/l benzene, 2.2 mg/l DRO, and 0.698 mg/l GRO in the groundwater. The highest contamination levels were found near the free product recovery well. Groundwater was encountered at 8 feet below ground surface. |
Robert Weimer |
| 5/16/2007 |
Update or Other Action |
July 31, 2006 groundwater monitoring event. Two monitoring wells were installed on 9/29/05. Up to 9 ug/l benzene, 1.35 mg/l DRO, and 0.223 mg/l GRO in the groundwater. The highest contamination levels were found near the free product recovery well. Groundwater was encountered at 8 feet below ground surface during the previous sampling event. |
Robert Weimer |
| 5/16/2007 |
Update or Other Action |
Review and approve workplan for decommissioning the product recovery well. The two monitoring wells are to be sampled for BTEX, GRO,and DRO. |
Robert Weimer |
| 6/17/2008 |
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 |
| 7/23/2008 |
Update or Other Action |
June 12, 2007 groundwater monitoring event. Up to 9 ug/l benzene, 26.6 mg/l DRO, and 0.694 mg/l GRO in the groundwater. The highest contamination levels were found near the free product recovery well. These concentations increase over the previous monitoring event. Groundwater was encountered at 8 feet below ground surface during a previous sampling event. The site recovery well was abandoned on June 12, 2007. 40 pounds of ORC advanced was placed in the recovery well before it was capped with bentonite clay. |
Robert Weimer |
| 7/23/2008 |
Update or Other Action |
ADEC approves workplan to sample monitoring wells MW-4 and MW-5 on an annual basis for BTEX, GRO, and DRO. The next groundwater sampling event is scheduled for July 25, 2008. |
Robert Weimer |
| 9/15/2008 |
Document, Report, or Work plan Review - other |
July 25, 2008 groundwater monitoring event. Up to 11 ug/l benzene, 1.9 mg/l DRO, and 0.14 mg/l GRO in the groundwater. The highest contamination levels were found near the free product recovery well. The concentation of benzene increased but the DRO and GRO decreased from the previous monitoring event. Depth to groundwater was 4.48 to 5.18 feet below ground surface. |
Robert Weimer |
| 8/16/2010 |
Document, Report, or Work plan Review - other |
June 23, 2009 groundwater monitoring event. Up to 11 ug/l benzene, 1.66 mg/l DRO, and 0.24 mg/l GRO in the groundwater. The highest contamination levels were found near the free product recovery well. The concentation of DRO increased but the GRO decreased from the previous monitoring event. Depth to groundwater was 4.50 to 5.30 feet below ground surface. Because DRO was found in monitoring well MW-4 on June 23, 2009, the sample was re-analyzed in the lab and the monitoring well was resampled on September 4, 2009 and was found to be non detect. |
Robert Weimer |
| 10/6/2011 |
Site Characterization Report Approved |
June 16, 2010 groundwater monitoring event. Up to 30.1 ug/l benzene, 1.8 mg/l DRO, and 1.09 mg/l GRO in the groundwater. The highest contamination levels were found near the free product recovery well. The concentation of benzene, GRO, and DRO increased from the previous monitoring event. Depth to groundwater was 3.1 to 5.0 feet below ground surface. A strong fuel odor was noted in monitoring well MW-5. The consultant recommends continued annual groundwater monitoring. |
Robert Weimer |
| 3/12/2013 |
Site Visit |
Site visit to observe current site conditions. |
Robert Weimer |
| 7/1/2013 |
Document, Report, or Work plan Review - other |
July 27, 2012 groundwater monitoring event. Up to 13.6 ug/l benzene, 1.3 mg/l DRO, and 0.48 mg/l GRO in the groundwater. The highest contamination levels were found near the free product recovery well. The concentation of benzene, GRO, and DRO decreased from the previous monitoring event. Depth to groundwater was 4.49 to 5.42 feet below ground surface. A strong fuel odor and light sheen was noted in monitoring well MW-5. The consultant recommends continued annual groundwater monitoring. |
Robert Weimer |
| 9/16/2015 |
Document, Report, or Work plan Review - other |
August 19, 2014 groundwater monitoring event. Up to 8.0 ug/l benzene, 1.0 mg/l DRO, and 0.28 mg/l GRO in the groundwater. The highest contamination concentrations were found near the free product recovery well. The concentation of benzene, GRO, and DRO decreased from the previous monitoring event. Depth to groundwater was 4.63 to 5.62 feet below ground surface. Product was noted in monitoring well MW-5, but was not measurable. The groundwater samples were collected with using peristaltic pump after purging. Because of the loss of volatiles using a peristaltic pump the BTEX and GRO results are considered biased low. Because the sample interval was not documented to be as close as possible to the soil/water interface as required the BTEX, GRO, and DRO results are considered biased low. |
Robert Weimer |
| 7/6/2016 |
Update or Other Action |
Based on the historical data at this site dating back to 2005, the sample results for Monitoring Well #4 (MW-4) have not indicated the presence of any contaminants of concern above method detection limits or were detected at levels well below the ADEC Table C Groundwater Cleanup Levels (18 AAC 75.345). Based on this information, groundwater monitoring from MW-4 is no longer required. MW-5 will remain under the August 13, 2014 requirements for biennial groundwater sampling and reporting. |
Darren Mulkey |
| 9/22/2016 |
Document, Report, or Work plan Review - other |
Received the July 19, 2016 groundwater monitoring report. MW-5 is the only well remaining that requires monitoring. During the sampling event no LNAPL was observed in MW-5. A sample and one duplicate were collected from MW-5 and tested for BTEX, GRO and DRO. Benzene was the only contaminant of concern that was detected exceeding ADEC Table C groundwater cleanup levels at 11.8 ug/L. |
Darren Mulkey |
| 7/12/2017 |
Meeting or Teleconference Held |
DEC staff met with ASIG A. Tuttle and consultant Ahtna Environmental, Inc. to discuss status and path forward. Biennial groundwater monitoring is currently conducted at this site. Currently this includes one well, MW-5. The last sampling event was conducted in 2016. Benzene was the only constituent above cleanup levels for the third consecutive event, at a concentration of 0.0115 mg/L with a stable trend indicated. The report, dated September 21, 2016, recommended monitoring be extended to every 5 years. ASIG needs to demonstrate that the nature and extent of contamination in the groundwater has been delineated to include VOCs and PAHs. A work plan will be submitted for 2017 to include sampling for VOCs and PAHs. |
Wendy Hansen |
| 10/17/2017 |
Document, Report, or Work plan Review - other |
DEC staff reviewed a work plan submitted by Ahtna Engineering Services, LLC to sample one onsite wells, MW-5 for GRO, DRO, fuel related VOCs, and PAH SIM using a bladder pump and low-flow techniques. One duplicate sample is planned. The sampling is scheduled to occur in October 2017. |
Wendy Hansen |
| 2/15/2018 |
Document, Report, or Work plan Review - other |
Staff provided comments to the 2017 groundwater monitoring report submitted on February 5, 2018, dated February 1, 2018. The report summarizes groundwater monitoring conducted in October 2017. Water level and LNAPL measurements were taken from MW-5. In addition, a sample and one duplicate were collected and tested for GRO, DRO, PAH, and petroleum-related VOCs. LNAPL was present in the well, measured at 1.44 inches using an interface probe. Samples were collected approximately one foot below the water column using low flow sampling techniques and a bladder pump. GRO (2.83 mg/l), DRO (13.1 mg/l), benzene (12.7 ug/l), ethylbenzene (48.7 ug/l), 1-methylnapthalene (104 ug/l), 2-methylnapthalene (117 ug/l), naphthalene (253 ug/l), and 1,2,4-trimethylbenzene (353 ug/l) were reported above Table C groundwater cleanup levels. Field duplicate precision was poor for several chemicals, potentially due to the presence of LNAPL. A Mann-Kendall analysis presented for DRO indicated a decreasing trend. DEC staff did not review the analysis at this time. The report recommended resampling MW-5 in 2018 and placement of a temporary well in the woods to the west or southwest to assess groundwater impacts. DEC staff also requested sampling MW-4 and verifying groundwater flow direction. |
Wendy Hansen |
| 4/3/2018 |
Meeting or Teleconference Held |
DEC staff met with ASIG (now Menzies) and Ahtna Environmental, Inc. to discuss site status and path forward. |
Wendy Hansen |
| 4/24/2018 |
Workplan Requested |
DEC staff issued a letter documenting path forward based on April 3, 2018 meeting and subsequent discussions. The letter requests 2018 activities include sampling wells MW-4 and MW-5, placement and sampling of a 3rd well to the west or southwest, and confirming groundwater gradient. |
Wendy Hansen |
| 7/5/2018 |
Document, Report, or Work plan Review - other |
Staff provided comments to draft work plan. The work plan was titled "Draft Work Plan Monitoring Well Installation, and Groundwater Sampling, 16th Avenue and C Street, Anchorage, Alaska" and dated June 28, 2018. The installation of one monitoring well is planned to the west of MW-4 and MW-5. Soil samples will be collected during installation. The newly installed well and the two of the existing wells (MW-4 and MW-5) will be sampled. |
Wendy Hansen |
| 7/30/2018 |
Document, Report, or Work plan Review - other |
Staff accepted responses to comments provided for the 2018 work plan. |
Wendy Hansen |
| 8/24/2018 |
Document, Report, or Work plan Review - other |
Staff received final 2017 Groundwater Monitoring Report. All DEC comments were satisfactorily addressed in the final report. |
Wendy Hansen |
| 3/1/2019 |
Document, Report, or Work plan Review - other |
Staff provided comments to the 2018 groundwater monitoring report submitted on January 31, 2019. The report summarizes well installation, soil sampling, and groundwater monitoring conducted in October 2018. One well (MW-6) was installed to the west to help determine groundwater flow direction and delineate groundwater contamination at the site. One soil sample was collected in duplicate from the soil/groundwater interface at 4-5 feet below ground surface and analyzed for GRO, DRO, PAH, and petroleum-related VOCs. The new well (MW-6) and existing wells MW-4 and MW-5 were sampled for GRO, DRO, PAH, and petroleum-related VOCs. Groundwater was determined to be flowing to the south/southeast. No contaminants were detected in the soil sample above cleanup levels. Groundwater samples were collected from the middle of the water column using low flow sampling techniques and a bladder pump. DRO (4.44 mg/l), benzene (6.01 ug/l), 1-methylnapthalene (33.8 ug/l), 2-methylnapthalene (41.2 ug/l), naphthalene (47.1 ug/l), and 1,2,4-trimethylbenzene (84.4 ug/l) were reported above Table C groundwater cleanup levels at MW-5. A Mann-Kendall analysis presented for DRO and benzene indicated no trend. DEC staff did not review the analysis at this time. The report recommended that groundwater depth measurements be collected and gradient calculated over time to determine if groundwater flow is consistent. It also recommended sampling all three site wells in the fall of 2019 to confirm results. |
Wendy Hansen |
| 4/19/2019 |
Document, Report, or Work plan Review - other |
Staff approved the final 2018 Groundwater Monitoring Report, dated April 1, 2019. A draft report was submitted on January 31, 2019. The final report incorporated responses to DEC comments that were provided March 1, 2019. |
Wendy Hansen |
| 8/13/2019 |
Update or Other Action |
Staff reviewed and approved 2019 field work plan to sample MW-4, MW-5, and MW-6 for petroleum related VOCs, GRO, PAH, and DRO, and measure groundwater elevations at all site monitoring wells in August and October. Sampling will be conducted in accordance with the 2018 work plan. |
Wendy Hansen |
| 6/24/2020 |
Update or Other Action |
Staff commented on draft 2019 groundwater report and approved of decommissioning well MW-6. The following comments were provided for the draft 2019 report:
1). Table 1-1 – All results were not converted from µg/l to mg/l (e.g., MW-4 benzene). The table
should include volatile organic compounds and polycyclic aromatic hydrocarbons that have
been detected.
2). Data Quality Review Sensitivity – This section should discuss whether the limits of detection are below screening/cleanup levels |
Todd Blessing |
| 1/13/2021 |
Document, Report, or Work plan Review - other |
Staff reviewed and approved of Draft Report for 2020 Monitoring Well Removal
16th Avenue and C Street, Anchorage, Alaska. The report documented the decommissioning of well MW-6 in accordance with ADEC guidance. |
Todd Blessing |
| 5/14/2021 |
Document, Report, or Work plan Review - other |
Staff reviewed and commented on a work plan to sample groundwater from the two existing wells. The work plan is dated April 29, 2021. |
Todd Blessing |
| 5/27/2021 |
Update or Other Action |
DEC staff reviewed Ahtna Solutions, LLC's response to DEC comments on the 2021 Groundwater Sampling work plan. All comments were accepted and a final work plan was requested. |
Todd Blessing |
| 8/2/2021 |
Site Characterization Report Approved |
On June 9, groundwater samples were collected from the two site wills MW-4 and MW-5. Results were consistent with previous findings, contaminants in MW-5 continue to exceed groundwater cleanup levels, DRO was 12.2 mg/L, 1-methylnaphthalene was 28.4 µg/L and naphthalene was 23.1 µg/L. DRO was detected in MW-4 at 0.688 mg/L. Continued biennial sampling was recommended. |
Shawn Tisdell |
| 1/24/2022 |
Workplan Requested |
Additional delineation requested for impacted media at the site. |
Shawn Tisdell |
| 6/27/2023 |
Meeting or Teleconference Held |
DEC project manager met with AFSC and Ahtna staff to discuss data gaps remaining at the site and identify a possible pathway towards site closure. |
Shawn Tisdell |
| 7/26/2023 |
Site Characterization Workplan Approved |
Scope of workplan is to advance three borings along the west side of the site near the fence and collect soil samples near the top of the smear zone where soil contamination is most likely to remain. Groundwater samples will also be collected from the two remaining monitoring wells. All sampling will be for petroleum contamination associated with Jet A fuel. |
Shawn Tisdell |
| 9/7/2023 |
Exposure Tracking Model Ranking |
A new updated ranking with ETM has been completed for source area 71572 1989 pipeline contamination. |
Shawn Tisdell |
| 9/26/2023 |
Site Characterization Workplan Approved |
This work plan replaces the 7/26/2023 work plan. The contractor was unable to collect soil samples using hand borings, so they decided to develop a new work scope that included using direct push technology. Boring locations for this new scope were moved 10 feet westward onto the neighboring property and to extend boring depth to 10 feet if contamination was observed at the 0-to-5-foot interval. Work is scheduled for October. |
Shawn Tisdell |
| 3/6/2024 |
Document, Report, or Work plan Review - other |
DEC received the draft 2023 AFSC Biennial Groundwater Sampling and Soil Data Gap Investigation Report. This report presents current contamination results in monitoring wells MW-4 and MW-5, located near the former pipeline, and the investigation into soil data gaps along the western portion of the site. |
Shawn Tisdell |
| 4/11/2024 |
Offsite Soil or Groundwater Disposal Approved |
One five gallon container of jet fuel contaminated soil from site characterization activities at both the 16th Avenue & C Street (this site) and 19th Avenue and C Street (Haz ID 419) was transported and disposed at US Ecology Viking Facility in Anchorage. |
Shawn Tisdell |
| 4/26/2024 |
Meeting or Teleconference Held |
Meeting was held with DEC, Ahtna, and AFSC staff in attendance. The discussion focused on the 2023 Soil Data Gap Investigation Report results and a plan to move forward with additional site characterization. |
Shawn Tisdell |
| 6/19/2024 |
Site Characterization Report Approved |
The 2023 AFSC Biennial Groundwater Sampling and Soil Data Gap Investigation Report has be reviewed and is approved. Results of this November 2023 investigation indicate soil contamination from the former pipeline extends further west than had previously been delineated. GRO, DRO, select VOCs and semi volatiles were observed above cleanup levels approximately 30 feet west of the pipeline location. The consultant recommended advancing additional soil borings and monitoring wells to the west, near the Cook Inlet Native Headstart building. The full report is available as an attachment. |
Shawn Tisdell |
| 8/30/2024 |
Meeting or Teleconference Held |
Teleconference held with Menzies Aviation and their new consultant from SLR to discuss the site history and path forward for additional site characterization of pipeline related contamination to the southwest, in the direction of the Cook Inlet Native HeadStart. Menzies plans to conduct additional soil and groundwater delineation of petroleum contamination toward the HeadStart building and will be preparing a workplan for this effort. |
Shawn Tisdell |
