| Action Date |
Action |
Description |
DEC Staff |
| 3/18/2011 |
Site Added to Database |
A new site has been added to the database |
Mitzi Read |
| 3/18/2011 |
Leaking Underground Storage Tank Release Confirmed - Petroleum |
LUST site created in CSP database for source area Diesel UST Dispenser, 79058 |
Mitzi Read |
| 3/21/2011 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed for source area id: 79058 name: Diesel UST Dispenser |
Mitzi Read |
| 3/22/2011 |
Underground Storage Tank Site Characterization or Assessment |
A 2000-gallon diesel tank, a 2000-gallon unleaded gasoline tank, and their associated piping and dispensers were removed on 10/16/10. Fuel stained soil was found below the diesel dispenser and along the side of the diesel tank. 120 cubic yards of contaminated soil was excavated and placed in a treatment cell (28 foot by 30 foot by 4 foot thick with 8 inches of clean gravel cover) in the former tank excavation. The bottom and sides of the flush with the ground surface treatement cell consist of a Typar liner. All excavation samples meet default cleanup levels. The highest contaminated stockpile sample collected was 362 mg/kg DRO, but the stained soil that was also put in the treatment cell and the soils deeper than the top 6 inches were not sampled. Only 10 field screening samples were collected 6 inches below the surface for the 120 cubic yards of contaminated soil. Need a work plan for properly characterizing the soil in the treament cell. Since the stained soil and the soil that was deeper than the top 6 inches in the cell was not sampled, some of the soil in the cell may also contain BTEX, GRO, and PAH's above cleanup levels. Based on results of the future characterization sampling further corrective action may be required. |
Robert Weimer |
| 3/22/2011 |
Leaking Underground Storage Tank Cleanup Initiated - Petroleum |
120 cubic yards of contaminated soil was excavated and placed in a treatment cell (28 foot by 30 foot by 4 foot thick with 8 inches of clean gravel cover) in the former tank excavation. |
Robert Weimer |
| 3/29/2011 |
Update or Other Action |
PRP letter sent to MEA. The letter includes cost recovery notification and requests a workplan by May 15, 2011 for characterizing the current contamination levels of the 120 cubic yards of contaminated soil that was excavated and placed in a treatment cell (28 foot by 30 foot by 4 foot thick with 8 inches of clean gravel cover) in the former tank excavation. Since the stained soil and the soil that was deeper than the top 6 inches in the cell was not sampled, some of the soil in the cell may also contain BTEX, GRO, and PAH's above cleanup levels in addition to DRO. |
Robert Weimer |
| 4/1/2011 |
Meeting or Teleconference Held |
Teleconference with Matthew Reisterer and Todd McCracken of MEA, and Ralph Hulbert of AlaskChem Engineering. We discussed that, as described by your consultant, “quite a few yards” of soil with visible petroleum contamination was not segregated from other excavated soils as required in regulation (18 AAC 78). We also discussed that the field screening and collection of analytical samples from the excavated soil was not done as required in regulation. We discussed the importance of characterizing the contaminated soil in accordance with the regulations so it can be determined whether those soils meet applicable cleanup levels. We also discussed that the “quite a few yards” of soil with visible petroleum contamination that was not segregated from the other excavated soils would likely exceed the direct contact cleanup levels and maximum allowable cleanup levels.
We further discussed that because the field screening, soil segregation, and analytical sampling of the 120 cubic yards of contaminated soil was not done as required in regulations, ADEC is requesting supplemental assessment work so we can evaluate the concentrations of contaminants in those soils and determine whether they will need or what portions will need further corrective action. The ADEC letter of March 29, 2011 requested a workplan by May 15, 2011 for characterizing the current contamination levels of the 120 cubic yards of contaminated soils.
ADEC shared MEA's concerns that because the field screening, soil segregation, and analytical sampling work was not done as required in regulations that there will be additional costs that could have been avoided. ADEC looks forward to assisting MEA in completing the necessary site work in the most cost-effective manner.
In the meeting it was requested that ADEC provide a follow up letter to provide more detail on what site work was not done in accordance with the regulations. ADEC will provide this information along with the reference to the applicable the section of the UST Procedures Manual (adopted by reference in regulation in 18 AAC 78.090(e)).
|
Robert Weimer |
| 4/5/2011 |
Update or Other Action |
ADEC follow up letter to provide more detail on what site work was not done in accordance with the regulations. We have provided this information below along with the reference to the applicable the section of the UST Procedures Manual (adopted by reference in regulation in 18 AAC 78.090(e)).
1. Field screening readings were not conducted as required. The report states that field screening readings were conducted with a PID using a “probe method” at 25 degrees F (the temperature documented in the field notes) without using a clean jar or clean ziplock bag for headspace readings as required in Section 4.4.2 of the UST Procedures Manual for PID field screening readings.
2. Only 10 field screening readings were recorded in the field notes for the 120 cubic yards of contaminated soil that was put in the treatment cell. Section 4.4.2 (8) of the UST Procedure Manual requires that “all field screening results must be documented in the field record or log book”.
3. Only 10 field screening readings were collected from the 120 cubic yards of contaminated soil to determine the locations where analytical samples are to be collected. For 120 cubic yards of soil a minimum of 12 field screening samples are required. Section 4.5.1 (1) of the UST Procedures Manual requires “at least one soil sample must be obtained from each 10 cubic yards of stockpiled soil for field screening purposes.”
4. Field screening readings were only collected 6 inches into the 120 cubic yards of contaminated soil that was put in the 4 foot deep treatment cell. Section 4.5.1 (1) of the UST Procedure Manual requires that “samples must be obtained from various depths in the pile, but none less than 18 inches beneath the exposed surface of the pile”.
5. Visibly contaminated soil was not segregated from the other excavated soil as required in Section 4.4 of the UST Procedures Manual that requires “If instruments or other observations indicate contamination, soil must be separated into stockpiles based on apparent degrees of contamination. At a minimum, soil suspected of contamination must be segregated from soil observed to be free of contamination.”
The ADEC again requests that MEA submit a workplan by May 15, 2011 for characterizing the current contamination levels of the 120 cubic yards of contaminated soil in a treatment cell. This needs to include the collection of field screening and analytical samples in accordance with ADEC regulations, from throughout the 4 foot thickness of contaminated soil in the treatment cell, including the soil with visible petroleum contamination.
|
Robert Weimer |
| 5/10/2011 |
Update or Other Action |
Letter from MEA's consultant responding to the DEC's April 5, 2011 letter that identified what site work was not done in accordance with the regulations. The response provided additional photos and described field readings and observations that were not documented in the field notes. The consultant estimated that there were 30 cubic yards of excavated soil that contained visible fuel staining and fuel odors. The response did not provide the requested work plan for characterizing the current contamination concentrations of the 120 cubic yards of soil placed in the treatment cell. The response instead requested closure for the site without further characterization. |
Robert Weimer |
| 9/19/2011 |
Update or Other Action |
Via email DEC informed MEA and their consultant that DEC would be conducting a peer review of the how the field screening, analytical sampling, and soil segregation of the 120 cubic yards of excavated soil generated during the UST removals was conducted, and MEA's request for site closure without further site work. Once the peer review has been completed DEC will issue a written response to MEA regarding the findings and what follow work will be required for this site. |
Robert Weimer |
| 10/14/2011 |
Update or Other Action |
Via email DEC informed MEA and their consultant that based on the peer review of the how the field screening, analytical sampling, and soil segregation of the 120 cubic yards of excavated soil generated during the UST removals was conducted, and MEA's request for site closure without further site work is denied. The results of the peer review are the following:
1) AlaskChem did not follow specific requirements stated in the UST Procedures Manual as referenced in 18 AAC 78 regarding segregation of contaminated soils, field screening practices, and analytical sampling of the excavated soil. DEC earlier letters had correctly identified these problem areas.
2) Sampling performed on the 120 cubic yard stockpile (i.e., placed into a cell on site where it was sampled), which included 30 cubic yards of contaminated soil with visible contamination with 90 cubic yards of soil that was not visibly contaminated, was not representative of the contaminated soils in the cell.
The DEC requests
1) Under a DEC site specific approved plan, further sampling of the cell is necessary to obtain data that is representative of the excavated contaminated soils that is in the cell currently on site.
2) DEC offers three options:
a) Remove all of the soil from the cell, segregate the visibly contaminated soil from the non visibly contaminated soil, and then sample the visibly contaminated soil pile and the non visibly contaminated soil pile by using approved field screening practices and collecting analytical laboratory data per the UST Procedures Manual; or,
b) Sample the cell using test pits (at least four) excavated to the base of the cell by performing field screening throughout the cell’s depth and based upon the highest two field screening per test pit, submit two discrete grab samples for laboratory analytical analysis per test pit plus one duplicate per every 10 analytical samples. A statistical method may be possible using a 95% UCL based upon the samples, although additional samples could be proposed. This approach is similar to what AlaskChem suggests in their May 9th response (page 4); or,
c) There is no need for re-sampling if the all of soil within the cell is removed to an approved off site treatment facility such as for thermal remediation. A request needs to be submitted for approval for transportation of the contaminated soil.
Based on the peer review comments and review of the file, DEC requests that a work plan be submitted by November 30, 2011 to adequately characterize the contaminated soil in the cell. Samples need to be analyzed for DRO using AK102, BTEX/GRO using AK 101, and at least one sample based upon the highest field screening result or the most visible contamination needs to be analyzed for PAHs using EPA Method 8270. |
Robert Weimer |
| 12/1/2011 |
Update or Other Action |
ADEC grants MEA an extention until January 31, 2012 for submitting a work plan for the confirmation sampling or treatment of the 120 cubic yards of soil in the treatment cell at the site. |
Robert Weimer |
| 8/30/2012 |
Document, Report, or Work plan Review - other |
DEC issues conditional approval letter for work plan to collect confirmation samples from the 120 yards of soil placed in the treatment cell at the site. The conditionally approved plan calls for digging 4 test pits to the base of the cell with 3 field screening samples collected from each test pit. Five analytical samples are to be submitted to the lab from visibly stained soil or highest field readings if visibly stained soil is not observed. The samples are to be analyzed for BTEX, GRO, and DRO with any sample exceeding a total of 500 mg/kg to be analyzed for PAHs. The work plan also contained other items/requests outside of the scope of the sampling plan requested by DEC, these were not approved. They included removing the migration to groundwater pathway, risk reduction, increasing the relative percent difference (RPD) for field duplicates, and how the sample results will be reviewed for Cleanup Complete detemination. |
Robert Weimer |
| 9/14/2012 |
Site Visit |
DEC staff conducted a site visit to observe the collection of the confirmation soil samples from the on-site soil treatment cell. |
Robert Weimer |
| 3/1/2013 |
Site Characterization Report Approved |
On September 14, 2012 six confirmation soil samples were collected from the soil in the onsite treatment cell. Up to 0.024 mg/kg toluene, and 50.6 mg/kg DRO in the samples collected. All sample met most stringent cleanup levels. Site recommended for Corrective Action Complete status. |
Robert Weimer |
| 3/1/2013 |
Exposure Tracking Model Ranking |
A new updated ranking with ETM has been completed for source area 79058 Diesel UST Dispenser. |
Robert Weimer |
| 3/4/2013 |
Cleanup Complete Determination Issued |
|
Robert Weimer |
