| Action Date |
Action |
Description |
DEC Staff |
| 12/21/1988 |
Interim Removal Action Approved |
(Old R:Base Action Code = SC - Site Control (Emergency Response)). Booms and pads placed around seep and across stream. An estimated 30,000 gallons of Jet A was released. |
Former Staff |
| 1/11/1989 |
Update or Other Action |
(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). Woodward Clyde sent to Butler an initial remediation report. Product recovery system initially to be recovery wells consisting of 42" culverts installed vertically 3' above water table and extending 2' below the water table. Groundwater liner installed to help keep fuel from discharging into creek. |
Former Staff |
| 5/18/1989 |
Interim Removal Action Approved |
(Old R:Base Action Code = REM - Removal / Excavation). Anchorage Sand and Gravel sent letter stating that 558.46 tons of fuel stained soil from Chester Creek spill were processed into non spec. black base material. |
Former Staff |
| 8/15/1989 |
Update or Other Action |
(Old R:Base Action Code = SI - Site Investigation). Hart Crowser data shows that high levels of petroleum hydrocarbons remain in soil. 132 gallons of product recovered from 5/2/89 to 11/13/89. Excavation of soils not recommended since it would require closing C Street. |
Former Staff |
| 7/2/1990 |
Update or Other Action |
To date 75.6 gallons of Jet A recovered at creek side recovery well and 66 gallons of Jet A has been recovered in the across 19th recovery well. |
Robert Weimer |
| 1/1/1992 |
Site Added to Database |
|
Former Staff |
| 6/15/1995 |
Site Ranked Using the AHRM |
Initial ranking. Action code added because it wasn't when the site was originally ranked. |
Eileen Olson |
| 12/8/1997 |
Site Ranked Using the AHRM |
Site reranked by staff. Changed Quantity Value from 1 to 2.1; Population Density Value from 8 to 10; Population Proximity Value from .5 to 1; Environmental/Recreation Area from 2 to 0, and multiple sources from "n" to "y". |
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 |
Staff met with Signature's environmental personnel to review the file and discuss site status. The Department notified Signature that it expects to request that Signature complete characterization of the site to determine whether soil and groundwater contamination is migrating or has diminished over time. |
Eileen Olson |
| 9/6/2000 |
Site Characterization Workplan Approved |
Sent letter conditionally approving plan dated August 31, 2000 "Groundwater Sampling, East 19th and C Street" |
Eileen Olson |
| 1/8/2001 |
Update or Other Action |
Received "Report for Soil and Groundwater Sampling, 19th Avenue and C Street Pipeline Release" dated December 28, 2000. The report documented up to 2,130 mg/l DRO and 1.8 mg/l GRO in groundwater and 378 mg/kg DRO in soil (but no soil sample was collected at the soil/water interface of the highest groundwater contamination location). The report recommends installing additional monitoring wells to help define the extent of the groundwater contamination. |
Eileen Olson |
| 11/3/2004 |
Update or Other Action |
Formerly CS92.22
File number issued: 2100.38.437 |
Aggie Blandford |
| 2/17/2005 |
Update or Other Action |
File review - RP needs to define the level and extent of the groundwater contamination and provide documentation on where the leak had occurred. Groundwater contamination has been documented on both sides of the creek, with the highest levels on the south side. |
Robert Weimer |
| 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 site work. Because of limited funding this year ASIG proposes to limit the work this year to the installation of 3 or 4 monitoring wells and groundwater sampling. They will submit a revised workplan for the installation of 3 or 4 monitoring wells. We discussed that they will need additional monitoring wells and soil samples prior to closure of the site. We also discussed that additional 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 place two along the southern edge of the creek and one to the southeast near the highest groundwater contamination area in 1999. Recovery wells are to remain for the time being. |
Robert Weimer |
| 6/17/2005 |
Update or Other Action |
Site ranked on ETM. |
Robert Weimer |
| 7/8/2005 |
Update or Other Action |
ADEC approves workplan to install and sample 3 monitoring wells to help define the extent of the groundwater contamination. The workplan also proposes to collect 1 soil sample near boring 19-SB5. |
Robert Weimer |
| 9/18/2006 |
Document, Report, or Work plan Review - other |
November 21, 2005 Soil and Groundwater Assessment Report. Three monitoring wells were installed on 9/29/05. Up to 4 ug/l benzene, 1.62 mg/l DRO, and 0.929 mg/l GRO in the groundwater. The highest contamination levels were found near the northern free product recovery well. Groundwater was encountered at 3.70 to 7.48 feet below ground surface. Groundwater flow direction is to the northwest toward Chester Creek. |
Robert Weimer |
| 5/16/2007 |
Update or Other Action |
July 31, 2006 groundwater monitoring event. Three monitoring wells were installed on 9/29/05. Up to 2 ug/l benzene, 5.02 mg/l DRO, and 0.85 mg/l GRO in the groundwater. The highest contamination levels were found near the northern free product recovery well. Groundwater was encountered at 3.88 to 7.72 feet below ground surface. Groundwater flow direction is to the northwest toward Chester Creek. |
Robert Weimer |
| 5/16/2007 |
Update or Other Action |
Review and approve workplan for decommissioning the two product recovery wells. The three monitoring wells are to be sampled for BTEX, GRO,and DRO. |
Robert Weimer |
| 6/23/2008 |
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 3 ug/l benzene, 3.55 mg/l DRO, and 0.64 mg/l GRO in the groundwater. The highest contamination levels were found near the north free product recovery well. These concentations have decrease over the previous monitoring event. Depth to groundwater was 3.88 to 7.72 feet below ground surface. The two product recovery wells were abandoned on June 12, 2007. 30 to 100 pounds of ORC advanced was placed in each recovery well before it was capped with bentonite clay. Groundwater results may be biased low due to elevated temperature in samples. |
Robert Weimer |
| 7/23/2008 |
Update or Other Action |
ADEC approves workplan for annual groundwater monitoring of monitoring wells MW-1, MW-2, and MW-3 for BTEX, GRO, and DRO. |
Robert Weimer |
| 4/23/2009 |
Document, Report, or Work plan Review - other |
July 25, 2008 groundwater monitoring event. Up to 2 ug/l benzene, 2.11 mg/l DRO, and 0.77 mg/l GRO in the groundwater. The highest contamination levels were found near the north free product recovery well. These concentations have decrease over the previous monitoring event. Depth to groundwater was 3.67 to 7.55 feet below ground surface. The two product recovery wells were abandoned on June 12, 2007. 30 to 100 pounds of ORC advanced was placed in each recovery well before it was capped with bentonite clay. |
Robert Weimer |
| 8/16/2010 |
Document, Report, or Work plan Review - other |
June 23, 2009 groundwater monitoring event. Up to 0.09 ug/l benzene, 1.51 mg/l DRO, and 2.08 mg/l GRO in the groundwater. The highest contamination levels were found near the free product recovery well. The concentation of GRO increased but the DRO amd benzene decreased from the previous monitoring event. Depth to groundwater was 3.82 to 7.85 feet below ground surface. Because DRO was found in monitoring well MW-2 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 still contaminated. |
Robert Weimer |
| 10/4/2011 |
Site Characterization Report Approved |
June 15, 2010 groundwater monitoring event. Up to 1.5 ug/l benzene, 1.5 mg/l DRO, and 1.71 mg/l GRO in the groundwater. The highest contamination levels were found near the free product recovery well. The concentation of GRO and benzene increased but the DRO decreased from the previous monitoring event. Depth to groundwater was 3.7 to 7.7 feet below ground surface. The groundwater flow direction was to the northwest toward Chester Creek. A petroleum odor was noted in monitoring well MW-2. The consultant recommends sampling all of the monitoring wells again in 2011. |
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 26, 2012 groundwater monitoring event. Up to 1.4 ug/l benzene, 1.23 mg/l DRO, and 1.39 mg/l GRO in the groundwater. The highest contamination levels were found near the free product recovery well. The concentations increased in 0 of the 3 monitoring wells sampled. Depth to groundwater was 3.66 to 7.84 feet below ground surface. The groundwater flow direction was to the northwest toward Chester Creek. |
Robert Weimer |
| 9/16/2015 |
Document, Report, or Work plan Review - other |
August 19, 2014 groundwater monitoring event. Up to 0.7 ug/l benzene, 1.0 mg/l DRO, and 0.83 mg/l GRO in the groundwater. The highest contamination levels were found near the free product recovery well. The concentrations increased in 0 of the 3 monitoring wells sampled. Depth to groundwater was 3.67 to 7.84 feet below ground surface. The groundwater flow direction is generally to the northwest toward Chester Creek. All three wells were purged prior to sampling. Monitoring wells MW-1 and MW-2 were sampled using a peristaltic pump and monitoring well MW-3 was sampled using a bailer. The sampling intervals were not documented in the report or field notes. Since a peristaltic pump and a bailer were used to collect the water samples the BTEX and GRO sample results are considered biased low due to the loss of volatiles using those collection methods. Also since the sample interval was not documented as being as close as possible to the soil/water interface the results for BTEX, GRO, and DRO are considered biased low. |
Robert Weimer |
| 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. The last round of sampling occurred in 2014. Concentrations of petroleum constituents have been below cleanup levels in three wells being sampled for the past four monitoring events, with apparent stable or decreasing trends. The last monitoring report, dated March 4, 2015, recommended site closure with Cleanup Complete status. ASIG needs to demonstrate that the nature and extent of contamination in groundwater has been fully delineated to include volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) consistent with current ADEC 18 AAC 75.345 Table C cleanup levels. ASIG will provide an updated work plan for sampling in 2017 to include VOCs and PAHs in accordance with ADEC sampling guidance. |
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 the three onsite wells, MW-1, MW-2, and MW-3 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 |
| 2/21/2018 |
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-1, MW-2, and MW-3. In addition, samples were collected and tested for GRO, DRO, PAH, and petroleum-related VOCs. One field duplicate was collected. No LNAPL was measured in the wells. Samples were collected approximately one foot below the water column using low flow sampling techniques and a bladder pump. No chemicals were detected in MW-1, and no exceedances of Table C groundwater clean up levels in MW-3. Benzene (6.46 ug/l), 1-methylnapthalene (40.7 ug/l), 2-methylnapthalene (36.5 ug/l), naphthalene (44.6 ug/l), and 1,2,4-trimethylbenzene (131 ug/l) were reported above Table C groundwater cleanup levels in MW-2. Alaska Water Quality Standards are applicable for MW-2. A Mann-Kendall analysis presented for DRO indicated a decreasing trend. DEC staff did not review the analysis at this time. The report recommended continued biennial sampling. Delineation of VOC and PAH constituents is needed. |
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 |
Update or Other Action |
DEC staff issued a letter documenting path forward based on April 3, 2018 meeting and subsequent discussions. The letter requests 2018 activities include sampling well MW-2 and collecting three pore water samples adjacent to Chester Creek (one near MW-2 and one each downgradient and upgradient of MW-2) to help determine the extent of contamination. The pore water samples are to be collected when groundwater is most likely to be recharging surface water in the creek. Placement of at least one monitoring well on the north side of Chester Creek was also requested. |
Wendy Hansen |
| 7/5/2018 |
Document, Report, or Work plan Review - other |
Staff provided comments to draft work plan. The work plan was titled "Monitoring Well Installation, Groundwater Sampling and Pore Water Sampling Draft Work Plan, 19th Avenue and C Street, Anchorage, Alaska", and is dated June 28, 2018. The installation of one monitoring well is planned to the north of Chester Creek. Soil samples will be collected during installation. The newly installed well (MW-7) and two of the existing wells (MW-2 and MW-3) will be sampled. In addition, three pore water samples will be collected along the south edge of Chester Creek. |
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 |
| 8/11/2018 |
Document, Report, or Work plan Review - other |
DEC received the final letter work plan for 2018 activities. The work plan was titled "Monitoring Well Installation, Groundwater Sampling and Pore Water Sampling Final Work Plan, 19th Avenue and C Street, Anchorage, Alaska". It is dated August 11, 2018. The sampling is planned for early August. |
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 monitoring well installation, groundwater sampling and pore water sampling report dated January 31, 2019. The report summarizes activities conducted in August 2018. One new groundwater well (MW-7) was installed north of Chester Creek. Two soil samples were collected during installation, one at 5-6 feet bgs and one at the soil/water interface (7-8 feet bgs). The soil samples were analyzed for GRO, DRO, PAH, and petroleum related VOCs. The new well and existing well MW-2 were sampled for GRO, DRO, PAH, and petroleum related VOCs. In addition, three pore water samples were collected from the bank of Chester Creek and analyzed for PAH and BTEX (TAH/TAqH). DRO was the only contaminant detected in the soil samples. The DRO concentration was below the most stringent cleanup level of 250 mg/kg. No chemicals were detected in MW-7, except for DRO which was below the cleanup level of 1.5 mg/l. 1-methylnapthalene (39 ug/l), naphthalene (150 ug/l), ethylbenzene (24 ug/l), total xylenes (230 ug/l), and 1,2,4-trimethylbenzene (270 ug/l) were reported above Table C groundwater cleanup levels in MW-2 and TAH/TAqH were above Alaska Water Quality Standards. Results for all three pore water samples were below Alaska Water Quality Standards for TAH/TAqH. Water samples were analyzed outside of holding time for PAH by one day. A Mann-Kendall analysis presented for DRO indicated a decreasing trend. DEC staff did not review the analysis at this time. The report recommended continued biennial sampling at MW-2 until concentrations are below cleanup levels. |
Wendy Hansen |
| 4/1/2019 |
Document, Report, or Work plan Review - other |
Staff received the final 2018 monitoring well installation, groundwater sampling and pore water sampling report dated April 1, 2019. All comments were satisfactorily addressed. The report recommended biennial sampling at MW-2. |
Wendy Hansen |
| 8/13/2019 |
Update or Other Action |
Staff reviewed and approved 2019 field work plan to sample wells MW-2 and MW-7 for petroleum related VOCs, GRO, PAH, and DRO. Sampling will be conducted in accordance with the 2018 work plan. |
Wendy Hansen |
| 3/24/2020 |
Document, Report, or Work plan Review - other |
Staff provided comments to the 2019 groundwater sampling report dated January 31, 2020. The report summarizes activities conducted in August 2019. Monitoring wells MW-7 and MW-2 were sampled. No chemicals were detected in MW-7, except for DRO and naphthalene which were well below the cleanup levels. DRO (1.52 mg/l), 1-methylnapthalene (69.2 ug/l), 2-methylnapthalene (61.2 ug/l), naphthalene (115 ug/l), and 1,2,4-trimethylbenzene (258 ug/l) were reported above Table C groundwater cleanup levels in MW-2 and TAH/TAqH were above Alaska Water Quality Standards. A Mann-Kendall analysis presented for DRO indicated a decreasing trend. The report recommended continued biennial sampling at MW-2 until concentrations are below cleanup levels. |
Wendy Hansen |
| 5/7/2020 |
Update or Other Action |
Staff reviewed RTCs and approved them with the caveat that ADEC may request further evaluation of the surface water/sediment pathway after reviewing the full report and site history. |
Todd Blessing |
| 6/4/2020 |
Update or Other Action |
Staff reviewed file and 2019 groundwater sampling report. A letter was submitted to Menzies Aviation to request sediment sampling in Chester Creek. Staff requested a work plan be developed to sample sediment in Chester Creek to evaluate the ecological pathway. |
Todd Blessing |
| 10/14/2020 |
Site Characterization Workplan Approved |
Staff reviewed and approved the Draft Work Plan for Sediment Sampling, 19th Avenue and C Street, Anchorage, AK (ADEC File No. 2100.38.437), and dated October 6, 2020. The work plan describes the collection of three sediment samples in the bed of Chester Creek in order to evaluate potential ecological risks. This work plan is approved. |
Todd Blessing |
| 2/22/2021 |
Site Characterization Report Approved |
DEC staff reviewed and approved of a AFSC 2020 Sediment Sampling Report. Three sediment samples were collected in Chester Creek and analyzed for PAHs. Detected PAHs were compared to NOAA SQuiRT screening values. Benz(a)anthracene, Benzo[a]pyrene, Chrysene, Fluoranthene, and Phenanthrene exceeded threshold effects levels. Naphthalene exceeded probable effects level. AHTNA communicated with AK Fish and Game and they determined the sediments impacted in Chester Creek from this release is not a high quality spawning or rearing habitat but does support some salmon rearing, more likely of the transient variety.
|
Todd Blessing |
| 2/23/2021 |
Workplan Requested |
Staff issued a letter to AFSC requesting submittal of a work plan for review to sample Chester Creek sediments a second time. |
Todd Blessing |
| 5/28/2021 |
Document, Report, or Work plan Review - other |
DEC reviewed the work plan, titled draft Work Plan for Groundwater and Sediment Sampling, 19th Avenue and C Street, Anchorage, Alaska was prepared by Ahtna Engineering Services, LLC. It describes the monitoring of groundwater contaminant levels and sediment contaminant levels in Chester Creek near 19th Avenue and C street. The work plan is approved and no comments were provided. |
Todd Blessing |
| 4/28/2022 |
Document, Report, or Work plan Review - other |
DEC reviewed the Draft Report for Groundwater and Sediment Sampling, 19th Avenue and C. MW-2 was sampled and had a DRO of 1580 ug/L, slightly higher than groundwater cleanup levels and slightly higher than the DRO concentration in that well sampled in 2019.
Sediment samples were collected in four locations along Chester Creek in close proximity to the pore water sampling locations of 2019. The sediment concentrations were compared to National Oceanic and Atmospheric Administration (NOAA)Screening Quick Reference Tables (SQuiRTs) Dutch Sediment Target Screening Value (DST),Threshold Effects Levels (TEL), and Probable Effects Levels (PEL).No results were above the PELs. Several polyaromatic hydrocarbons were above DSTs and TELs in SS-1, SS-2, and SS-4. SS-1 was located upgradient of the site on the east side of C-street and likely represents contamination from an upgradient source.
Monitoring Well MW-7 was decommissioned. |
Shawn Tisdell |
| 7/18/2023 |
Site Characterization Workplan Approved |
DEC reviewed and approved the groundwater sampling work plan to proceed for a late July 2023 sampling event. MW-2 will be gauged, purged, and sampled for fuel related chemicals (VOCs, GRO, DRO and PAHs). A groundwater sampling report will be prepared and submitted six weeks after receipt of the laboratory report. |
Shawn Tisdell |
| 12/8/2023 |
Site Characterization Report Approved |
The 2023 Biennial Groundwater Monitoring Report was reviewed and approved. MW-2 was sampled on 7/27/2023 and results indicate that it continues to have contaminant concentrations above DEC groundwater cleanup levels. this well is located next to Chester Creek and is adjacent the former excavation area. Dissolved concentrations of 1,2,4-trimethylbenzene, naphthalene, and 1-methylnaphthalene were above their respective CULs. Contaminant concentration trends for DRO were evaluated by Mann-Kendall analysis. Results of the trend analysis indicate a decreasing trend with a confidence level of greater than 95%. Ahtna recommends continuing the biennial sampling of MW-2 for diesel range organics, fuel related volatile organic compounds and polyaromatic hydrocarbons until all analytes are below cleanup levels or a risk assessment is completed. |
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 (Haz ID 593) and 19th Avenue and C Street (this site) was transported and disposed at US Ecology Viking Facility in Anchorage. |
Shawn Tisdell |
