| Action Date |
Action |
Description |
DEC Staff |
| 10/21/2009 |
Site Added to Database |
A new site has been added to the database |
Mitzi Read |
| 10/21/2009 |
Leaking Underground Storage Tank Release Confirmed - Petroleum |
LUST site created in CSP database for source area Two 10,000-gallon Gasoline USTs - Tanks 1 & 2, 78819 |
Mitzi Read |
| 10/21/2009 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed for source area id: 78819 name: Two 10,000-gallon Gasoline USTs - Tanks 1 & 2 |
Mitzi Read |
| 11/2/2009 |
Potentially Responsible Party/State Interest Letter |
DEC staff issued a letter on November 2nd to Kathleen Stadem, following a telephone conversation with her regarding her potential responsible party status. Ms. Stadem was informed that she is a potential responsible party and that DEC will recover the costs associated with our oversight work from the responsible party/parties (AS 46.03.010 and AS 46.08.070). In the letter, DEC requested that Ms. Stadem hire a qualified person to conduct a release investigation in accordance with 18 AAC 78.090. Your consultant will need to draft a release investigation work plan for CSP review and approval prior to conducting any additional work. The deadline for submittal of this work plan is December 31, 2009. |
Todd Blessing |
| 11/16/2009 |
Update or Other Action |
DEC staff reviewed Alaska Chem Engineering’s “Underground Storage Tank Site Assessment Report Phase I”, dated November 5, 2009. In this report, Alaska Chem Engineering (AlaskChem) documented the removal of two 10,000-gallon gasoline underground storage tanks (Tank Nos. 1 & 2) in October 2009. Soil samples collected from the excavation pit revealed elevated levels of gasoline constituents; in particular, benzene and toluene were detected at levels that exceed 18 AAC 75.341 migration to groundwater cleanup levels. Contaminated soil was observed in soil to 16.5 feet below ground surface where groundwater was encountered. Clean soil was brought in to backfill the excavation pit and bring the area up to grade.
AlaskChem constructed a landfarming cell on the northeast corner of the subject site and deposited 415 cubic yards of contaminated soil with an average depth of 14 inches. AlaskChem informed the CSP program that the landfarmed soil was not placed on a liner which is required under 18 AAC 78.274(a)(3). Please note that CSP is concerned that the leaching of contaminated soil from the landfarm cell may impact groundwater and consequently, CSP will require a groundwater monitoring well to be installed downgradient of the landfarmed cell to confirm that groundwater is not impacted. Additionally, CSP will require that your consultant develop a site control plan in accordance with 18 AAC 78.250(e)(8).
AlaskChem notified CSP in an email dated November 9, 2009 that three groundwater monitoring wells were installed at the subject site and analyzed for GRO/BTEX according to methods AK101 and SW 8021B. One groundwater monitoring well was installed in the former footprint of the underground storage tanks; a second well was installed south of the first well and a third well was installed in between the second and first well. |
Todd Blessing |
| 11/16/2009 |
Leaking Underground Storage Tank Cleanup Initiated - Petroleum |
|
Todd Blessing |
| 12/2/2009 |
Update or Other Action |
DEC staff reviewed Alask Chem Engineering's Underground Storage Tank Phase II, Groundwater Assessment”, dated November 2009. Alask Chem Engineering (AlaskChem) documented the installation and sampling of three groundwater monitoring wells and the on-site drinking water well. One groundwater monitoring well (A) was installed within the footprint of the former Underground Storage Tank Array. The second well (B) was installed roughly 100 feet south of well A and a third well (C) was installed roughly 25 feet southwest of well (A). Groundwater was found to be roughly 15 feet below ground surface. Collected groundwater samples were analyzed for GRO/BTEX by a DEC approved laboratory. Contaminants of concern were not detected above CSP cleanup levels defined in 18 AAC 75.345 Table C in wells B, C, and the drinking water well. In well A, benzene was detected in groundwater at a level of 14 µg/L, which exceeds the CSP cleanup level of 5µg/L. Groundwater elevation data suggests groundwater flows south to south east.
|
Todd Blessing |
| 9/20/2010 |
Update or Other Action |
DEC staff reviewed and commented on Alaska Chem Engineering’s “Former Mom & Pop Store, UST No. 2409, File 2245.26.032; Status and Work Plan”, dated September 4, 2010. In this report, Alaska Chem Engineering (AlaskChem) documented the results of 2010 summer field activities which included: groundwater monitoring and landfarming of contaminated soil. Groundwater samples were collected from Well Number A and tested for GRO and BTEX. Groundwater samples were not collected from the other three on-site wells during the August 2010 sampling event. Benzene and o-xylene were the only parameters detected in collected samples. Benzene and o-xylene were detected at levels of 3.24 and 3.48 µg/L; respectively. DEC has reviewed this data package and determined that the analytical results are biased low estimates due to the measurement of cooler temperatures above 6 degrees centigrade. Since benzene was detected at levels close to the cleanup level of 5 µg/L, further groundwater monitoring of Well A will be required.
AlaskChem and provided a work plan for evaluating contaminant concentrations in landfarmed soil on-site. AlaskChem has previously notified DEC that 415 cubic yards of contaminated soil has been spread on the northeast corner of the property to a depth of 14 inches. Fertilizer has been applied to the landfarm cell to promote natural biodegradation. AlaskChem proposed to mark out 42 rectangular plots in the 80 foot by 120 foot landspread cell. Each plot will be field screened by driving a probe 1 foot deep in the center of each plot and tested with a photoionizing detector (PID). Five locations with the greatest PID readings will be sampled at either 1 foot or two foot depths and tested for GRO/BTEX according to CSP approved methods.
AlaskChem and provided a work plan for evaluating contaminant concentrations in landfarmed soil on-site. AlaskChem has previously notified DEC that 415 cubic yards of contaminated soil has been spread on the northeast corner of the property to a depth of 14 inches. Fertilizer has been applied to the landfarm cell to promote natural biodegradation. AlaskChem proposed to mark out 42 rectangular plots in the 80 foot by 120 foot landspread cell. Each plot will be field screened by driving a probe 1 foot deep in the center of each plot and tested with a photoionizing detector (PID). Five locations with the greatest PID readings will be sampled at either 1 foot or two foot depths and tested for GRO/BTEX according to CSP approved methods.
|
Todd Blessing |
| 9/20/2010 |
Update or Other Action |
DEC staff issued a letter on September 20, 2010 commenting on Alaska Chem Engineering’s “Former Mom & Pop Store, UST No. 2409, File 2245.26.032; Status and Work Plan”, dated September 4, 2010. DEC requested that Ms. Stadem hire a qualified person to conduct an additional groundwater investigation. Groundwater samples shall be collected from wells A and D and analyzed for GRO/BTEX to confirm the following:
• The levels of GRO/BTEX in groundwater beneath the former leaking underground storage tank do not exceed CSP cleanup criteria;
• That GRO/BTEX in landfarmed soil is not leaching into groundwater and migrating in a south or southeasterly direction.
DEC also approved of AlaskChem’s landfarming closure sampling work plan, dated September 4, 2010.
|
Todd Blessing |
| 2/18/2011 |
Document, Report, or Work plan Review - other |
DEC reviewed and approved of AlaskChem's titleed "Former Mom & Pop Store, UST no. 2409, File 2245.26.032", dated January 24, 2011. Alaskchem proposed to sample wells A and D with disposal bailers to be analyzed for GRO/BTEX. DEC approved of the work plan provided groundwater is sampling in accordance with DEC's May 2010 Field Sampling Guidance. |
Todd Blessing |
| 5/23/2011 |
Document, Report, or Work plan Review - other |
DEC staff reviewed AlaskChem Engineering's "Former Mom & Pop Store, UST No. 2409, File 2245.26.032; Groundwater report." This report discusssed the February 2011 sampling of on-site wells A and D for GRO and BTEX. In these samples, benzene was the only contaminant of concern detected; benzene was detected at a level of 0.876 mg/L in well A. No contaminants of concern where detected in monitoring well D samples. |
Todd Blessing |
| 5/25/2011 |
Document, Report, or Work plan Review - other |
DEC staff reviewed and approved of AlaskChem's well decommissioning work plan dated, May 25, 2011. Groundwater monitoring wells A,B, and C will be decommissioned by cutting the casing 3 feet below ground surface, filling each well casing voids with a slury of bentonite chips and sand, and capping the well casing with a slurry of bentonite chips. |
Todd Blessing |
| 7/8/2011 |
Update or Other Action |
DEC staff reviewed and approved of AlaskChem Engineering's well decommissing report dated June 1, 2010. Monitoring wells A, B, anc C were decommissioned according to AlaskChem's May 2011 work plan. |
Todd Blessing |
| 7/21/2011 |
Cleanup Complete Determination Issued |
Based on a review of the administrative file, contaminated soil (above 18 AAC 75.341 Table B1 migration to groundwater values) remains in place in the footprint of the former 10,000 gallon USTs at roughly 16 feet below ground surface. However, the levels of contaminants in on-site groundwater do not exceed 18 AAC 75.345 Table C values. Remaining contaminated soil is de-minimis in volume, completed exposure pathways are believed to pose an insignificant exposure risk. In summary, ADEC has determined there is no unacceptable risk to human health or the environment, and this site will be granted a Corrective Action Complete determination.
Although a Corrective Action Complete determination has been granted, ADEC approval is required for off-site soil disposal in accordance with 18 AAC 78.600(h). It should be noted that movement or use of potentially contaminated soil in a manner that results in a violation of 18 AAC 70 water quality standards is unlawful.
This determination is in accordance with 18 AAC 78.276(f) and does not preclude ADEC from requiring additional assessment and/or cleanup action if future information indicates that this site may pose an unacceptable risk to human health or the environment.
|
Todd Blessing |
| 7/10/2012 |
Update or Other Action |
DEC issued a state letter of interst to Mr. Tzou, the current owner. |
Todd Blessing |
