| Action Date |
Action |
Description |
DEC Staff |
| 6/16/2010 |
Update or Other Action |
On June 16, 2010 a Chevron contractor was conducting induction metal detection, magnetometry, and ground penetrating radar techniques in preparation for the proposed installation of a soil vapor extraction/air sparging remediation system on the Thrifty property when they detected large objects in the subsurface that appeared to be buried tanks. On June 18, 2010 a vac truck was used to clear soil at two locations, that confirmed the top of at least one buried tank at 5.5 feet below ground surface. |
Robert Weimer |
| 2/27/2012 |
Update or Other Action |
On October 18, 2011 Thrifty's consultant used a vac truck to advance test pits in the area that Chevron's consultant had found a buried tank. Thrifty's consultant found two tanks next to each other with the top of the tanks at 5.5 feet below ground surface, and associated piping in that area. Thrifty plans to removed the tanks and piping once the ground thaws in 2012. |
Robert Weimer |
| 8/7/2012 |
Document, Report, or Work plan Review - other |
Thrifty's consultant (EMI) provided a work plan for the planned assessment of the buried tanks and piping found on their property by Chevron in 2011. |
Robert Weimer |
| 8/24/2012 |
Document, Report, or Work plan Review - other |
DEC provided comments Thrifty's consultant's (EMI) provided a work plan for the planned assessment of the buried tanks and piping found on their property by Chevron in 2011. DEC requested a revised work plan with the changes requested. |
Robert Weimer |
| 8/28/2012 |
Document, Report, or Work plan Review - other |
May 22, 2012 semi-annual groundwater monitoring conducted by Chevron's consultant, which includes 10 monitoring wells currently being monitored on the Thrifty property. Up to 25 mg/l GRO, and 140 ug/l benzene. Concentrations increased in 5 of the 18 total project monitoring wells sampled by Chevron. Groundwater flows to the south by southwest. Depth to groundwater is 10.67 to 12.92 feet below ground surface. |
Robert Weimer |
| 9/13/2012 |
Update or Other Action |
Thrifty's consultant (EMI) update that they are having a structural engineer look at whether some of the tanks can't be removed because of nearby canopy supports. The plan to dig some test pits in mid-October 2012 to collected information for a revised assessment work plan. |
Robert Weimer |
| 4/2/2013 |
Document, Report, or Work plan Review - other |
DEC received a structural investigation report from a structural engineer that the removal of the two tanks are removed it might endanger the supports to the roof overhang. |
Robert Weimer |
| 4/9/2013 |
Document, Report, or Work plan Review - other |
DEC has reviewed March 26, 2013 draft work plan for the additional tanks and piping found on the Thrify property. DEC requests that a revised work plan be submitted for review and approval with the following modifications: 1. Tanks and piping that are to be closed must be removed from the ground if there is contamination, unless it is demonstrated to DEC that the removal would endanger existing structures. At least two of the tanks (west and east) are not near any structures. 2. All of the piping associated with the tanks will need to be removed and assessed. Any additional tanks identified will need to be register, properly closed, and assessed (field screening and analytical samples) as per 18 AAC 78. The piping samples must be collected within 2 feet below the depth of the piping. 3. All excavated and vacuumed removed soil will need to have field screening and analytical samples collected. See the UST Procedures manual for field screening and analytical sampling requirements that need to be in the work plan. 4. Because volatile samples need to be collected a vacuum truck is not allowed to be used within 4 feet horizontally or vertically of any sample location. 5. Need to add 1,2-DCA and PCBs to the analysis methods. 6. The assessment report needs to include complete copies of all field notes. 7. The DEC project manager, Robert Weimer must be notified at least 3 days prior to conducting field work. 8. Locations that appear to have been former dispenser areas (such as the end of piping runs) will need to be field screened and have analytical samples collected in accordance with the UST Procedures Manual and 18 AAC 78. |
Robert Weimer |
| 4/11/2013 |
Document, Report, or Work plan Review - other |
September 20, 2012 semi-annual groundwater monitoring conducted by Chevron's consultant, which includes 10 monitoring wells currently being monitored on the Thrifty property. Up to 130 mg/l GRO, and 320 ug/l benzene. Concentrations increased in 12 of the 19 total project monitoring wells sampled by Chevron. Groundwater flows to the south by southwest. Depth to groundwater is 10.43 to 12.73 feet below ground surface. Groundwater sampling was conducted with no purge using bailers. Since bailers were used the BTEX and GRO results may be biased low. |
Robert Weimer |
| 2/10/2014 |
Document, Report, or Work plan Review - other |
May 13, 2013 semi-annual groundwater monitoring conducted by Chevron's consultant, which includes 10 monitoring wells currently being monitored on the Thrifty property. Up to 79.7 mg/l GRO, and 1,610 ug/l benzene. Concentrations increased in 6 of the 17 total project monitoring wells sampled by Chevron. Groundwater flows to the south west. Depth to groundwater was 11.05 to 13.09 feet below ground surface. Samples were collect by both no-purge (Hydrasleeve) and purge (bladder pump) methods. The sampling interval for the hydrasleeve and bladder pump was not documented in the field notes. The sample results between to the two methods were not consistent (for example MW-11 was non detect (<0.1 mg/l) GRO and non detect (<1.0 ug/l) benzene with the no-purge hydrasleeve but was 6.19 mg/l GRO and 19.4 ug/l benzene with the purged bladder pump sampling). |
Robert Weimer |
| 4/25/2014 |
Document, Report, or Work plan Review - other |
September 23, 2013 semi-annual groundwater monitoring by Chevron's consultant, which includes 10 monitoring wells currently being monitored on the Thrifty property. Up to 218 mg/l GRO, and 594 ug/l benzene. Concentrations increased in 5 of the 19 total project monitoring wells sampled by Chevron. Groundwater flows to the south west. Depth to groundwater was 10.06 to 12.31 feet below ground surface. Samples were collect by no-purge (Hydrasleeve) method. Because the sampling interval for the hydrasleeve was not documented in the field notes the results are considered biased low. |
Robert Weimer |
| 5/7/2014 |
Document, Report, or Work plan Review - other |
ADEC receives a revised work plan for conducting the in-place closure assessment of tank 3&4 systems. |
Robert Weimer |
| 5/9/2014 |
Document, Report, or Work plan Review - other |
ADEC conditionally approves the revised work plan for conducting the in-place closure assessment of tank 3&4 systems. The conditions are: 1. The assessment report is to include complete copies of field notes.
2. The ADEC project manager Robert Weimer is to be notified at least 3 days prior to conducting the field work if the field work is to begin on a Saturday - Monday, or 24 hours prior to field work beginning on a Tuesday - Friday .
3. The entire length of all piping (including the one running to the northeast) need to be located and assessed. The length and end of each piping run must be identified and assessed. This includes locating and assessing the portions of the piping on the other side of the porte corche. Any portions of the piping that can be safely removed need to be removed.
4. If a vacuum truck or air knife is used, it is not to be used within 4 feet horizontally or vertically of any volatile sample location if safely possible.
5. If any portion of the Underground Storage Tank (UST) system (which includes all piping, tanks, and potential dispenser locations) extend outside of the property boundaries and are not assessed as part of this work they will need to be assessed to complete the site assessment as required in 18 AAC 78.090 at a later date no later than August 1, 2014. If there are problems with getting access to those properties the DEC will be contacted to see if they can assist in helping to get access to those properties.
6. Because dispenser islands typically contain multiple dispensers, multiple field reading locations and depths (including beneath the individual dispenser locations) are required to assess those areas. The end of each piping run and potential dispenser areas identified on air photos need field readings. At least one analytical sample is to be collected based on field readings and observations. If field readings or observations indicate that a release may have occurred at multiple dispenser locations then analytical samples need to be collected at each of those locations.
7. If field readings or observations indicate that a release may have occurred at multiple piping locations then analytical samples need to be collected at each of those locations.
8. Suspected clean soils are not to be used as backfill within the groundwater.
9. 8260B analysis needs to include 1,2-DCA.
10. Check with the lab if the EDB analysis needs to be by method 8011 to get the needed detection limit. EDB analysis is not required for all samples, just at the most likely contaminated location per source area.
11. PAH analysis is not required for just 10% of the total number of samples, it is required at the most likely contaminated location per source area.
12. Stockpile field screening locations need to be a minimum of 18 inches into the stockpile and from throughout the stockpile.
13. Field readings and observations need to be conducted along the entire depth of the sidewall to determine the most likely contaminated depth for the collection of sidewall samples.
14. On page 6 for the excavation pit surfaces and test pits the test method needs to be the full 8260B instead of the 8021B listed.
15. On page 7 for the common dispenser location, see item 6 above.
16. For the tanks there needs to be assessment test pits or borings near the ends of the tanks in addition to the south side.
|
Robert Weimer |
| 6/17/2014 |
Site Visit |
Site visit to observe closure in-place of two 1,000 gallon USTs. High field reading found at the vent piping. Sections of piping were left in place and former dispenser island was not sampled at this time because it was in the road right of way and they did not have a permit to excavated soil there. Discussed with consultant that additional assessment work would be required. |
Robert Weimer |
| 12/10/2014 |
Document, Report, or Work plan Review - other |
June 17, 2014 in-place closure of two 1,000 gallon USTs. High field reading found at the vent piping. Sections of piping to a former dispenser island were left in place and not sampled at this time because it was in the road right of way and they did not have a permit to excavated soil there. Discussed with consultant that additional assessment work would be required to define the extent of the contamination and to complete the assessment of the piping/dispensers in the road right-of-way. The east end of the tanks did not have a test pit assessment as required in the conditional approval letter. Up to 530 mg/kg GRO, 450 mg/kg DRO, 0.0826 mg/kg benzene, 2.76 mg/kg ethylbenzene (0.13 mg/kg MTGW cleanup level), 36.9 mg/kg total xylenes (1.5 mg/kg MTGW cleanup level), 6.16 mg/kg naphthalene (0.038 mg/kg MTGW cleanup level), 3.75 mg/kg 1-methylnaphthalene (0.41 mg/kg MTGW cleanup level), 7.5 mg/kg 2-methylnaphthalene (1.3 mg/kg MTGW cleanup level), 43 mg/kg chromium, and 8.7 mg/kg arsenic left in-place in the areas sampled. The 45 cubic yards of excavated soil had up to 0.143 mg/kg benzene, and 0.0411 mg/kg PCBs and was placed back in the excavation on a liner. |
Robert Weimer |
| 1/5/2015 |
Document, Report, or Work plan Review - other |
May 14, 2014 semi-annual groundwater monitoring by Chevron's consultant, which includes 10 monitoring wells currently being monitored on the Thrifty property. Up to 7.99 mg/l GRO, and 160 ug/l benzene. Higher concentrations may exist because some samples arrived frozen/broken at the lab and were not analyzed. Two samples were not properly preserved in the field. Three samples were analyzed outside holding times. Concentrations increased in 9 of the 18 total project monitoring wells sampled by Chevron. Groundwater flowed to the south west. Depth to groundwater was 10.64 to 12.74 feet below ground surface. Samples were collect by purge method using a bladder pump. Samples were collected from within the top foot of the water column. |
Robert Weimer |
| 5/27/2015 |
Site Added to Database |
A new site has been added to the database |
Mitzi Read |
| 5/27/2015 |
Leaking Underground Storage Tank Release Confirmed - Petroleum |
LUST site created in CSP database for source area Two 1,000-Gallon Gasoline USTs 3 & 4, 79774 |
Mitzi Read |
| 5/27/2015 |
Potentially Responsible Party/State Interest Letter |
Potentially Responsible Party / State Interest Letter sent to Floyd Family Investments. Letter requests a release investigation work plan by July 1, 2015 for east end of tank and dispenser area in right-of-way and requests corrective action plan by September 15, 2015 for contaminated backfill and any other remaining contamination. |
Robert Weimer |
| 5/27/2015 |
Document, Report, or Work plan Review - other |
October 15, 2014 semi-annual groundwater monitoring by Chevron's consultant, which includes 10 monitoring wells currently being monitored on the Thrifty property. Up to 52.3 mg/l GRO, and 436 ug/l benzene in those monitoring wells. The highest concentrations were on the Thrifty property. Concentrations increased in 8 of the 19 monitoring total project wells sampled by Chevron. Groundwater flowed to the southwest. Depth to groundwater was 10.44 to 12.55 feet below ground surface. Samples were collect by no-purge method using Hydrasleeves. Samples were collected at the top of the water column as required. |
Robert Weimer |
| 5/27/2015 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed for source area id: 79774 name: Two 1,000-Gallon Gasoline USTs 3 & 4 |
Mitzi Read |
| 6/30/2015 |
Leaking Underground Storage Tank Cleanup Initiated - Petroleum |
Administrative action addition for grant reporting purposes. |
Evonne Reese |
| 8/4/2015 |
Update or Other Action |
By August 14, 2015 they plan to excavate the 45 cubic yard contaminated soil stockpile that was used as backfill on top of the tanks during the in-place tank closure in 2014. The 45 cubic yard stockpile is to be transported to the Anchorage Regional Landfill for disposal. They plan to submit a work plan by August 31, 2015 to conduct the requested release investigation near the Porte Corche and the former dispenser area. The plan to conduct that work in October 2015. |
Robert Weimer |
| 8/4/2015 |
Offsite Soil or Groundwater Disposal Approved |
ADEC approves request to transport the 45 cubic yard contaminated soil stockpile that was used as backfill on top of the tanks during the in-place tank closure in 2014 to the Anchorage Regional Landfill for disposal. The soil it scheduled to be excavated by August 14, 2015. |
Robert Weimer |
| 9/18/2015 |
Document, Report, or Work plan Review - other |
ADEC provided comments on the August 31, 2015 supplemental site assessment release investigation work plan. The work plan is for the assessment at the east ends of the tanks, the contamination found at 2.5 feet below ground surface at the Lab 03 location, and the assessment of the piping and dispensers in the right-of-way along Spenard Road. |
Robert Weimer |
| 10/6/2015 |
Document, Report, or Work plan Review - other |
ADEC provided additional comments for the dispenser and piping assessment portion of the work plan:
1. Each joint, 10 foot length, and ends of the piping needs to be located, assessed, and removed.
2. Dispenser/piping samples to be analyzed for VOC (method 8260), GRO, DRO, lead with the most likely contaminated location also analyzed for EDB (method 8011) and PAH.
3. Stockpile samples to be analyzed for VOC (method 8260), GRO, DRO, lead with the most likely contaminated location and duplicate also analyzed for EDB (method 8011) and PAH.
4. Stockpile field screening locations need to be collected from the areas of most likely contamination based on field observations (if shallower) and from locations a minimum of 18 inches from the exposed surface throughout the stockpile. For stockpiles up to 50 cubic yards a minimum of 5 field screening locations. The excavated soil needs to be secured on a liner and covered as per 18 AAC 78.
5. If the sample jars are not filled just before collecting the field screening soil, the analytical samples are to be collected within 1 hour after reviewing the field screening readings from freshly exposed soil from a similar depth/soil type/observations 6 to 12 inches away from the field screening location.
6. Complete copies of field notes are to be included with the report.
|
Robert Weimer |
| 10/7/2015 |
Site Visit |
Site visit to observe the assessment of the dispenser area near Spenard road. |
Robert Weimer |
| 10/21/2015 |
Document, Report, or Work plan Review - other |
ADEC approves the October 15, 2015 Supplemental Site Assessment / Release Investigation Work Plan under the condition that the drill cuttings and decontamination water are properly stored on property until approved by ADEC under a separate request for treatment/disposal. The work plan proposes to collected soil samples from two soil borings (one at east end of the tanks, and one near the vent piping release area near the porte corche. |
Robert Weimer |
| 10/26/2015 |
Document, Report, or Work plan Review - other |
ADEC approves the October 15, 2015 Supplemental Site Assessment / Release Investigation Work Plan with modifications proposed on October 23, 2015. The decontamination water is to be disposed of in the on-property wash bay drain unless the water has a sheen or free product (in which case it will be properly stored on property until approved by ADEC under a separate request for treatment/disposal).
The drill cuttings will be placed back in the borings unless they appears to be grossly contaminated in which case it will be properly stored on property until approved by ADEC under a separate request for treatment/disposal). |
Robert Weimer |
| 10/29/2015 |
Site Visit |
Site visit to observe sampling of two soil borings as part of a release investigation. |
Robert Weimer |
| 11/16/2015 |
Document, Report, or Work plan Review - other |
April 21, 2015 semi-annual groundwater monitoring by Chevron's consultant, which includes 4 monitoring wells currently being monitored on the Thrifty property. Up to 56.0 mg/l GRO, and 1,900 ug/l benzene. The highest concentrations were on the Thrifty property. Concentrations increased in 2 of the 4 monitoring wells sampled on the property. Groundwater flowed to the south west. Depth to groundwater was 11.72 to 12.97 feet below ground surface. Samples were collect by no-purge method using Hydrasleeves. Samples were collected at the top of the water column as required. |
Robert Weimer |
| 12/21/2015 |
Offsite Soil or Groundwater Disposal Approved |
On August 13, 2015 the 45 tons of contaminated soil that generated during 2014 tanks closure and used as backfill in a lined area was re-excavated and transported to the Anchorage Regional Landfill for disposal in accordance with an approved plan. |
Robert Weimer |
| 12/22/2015 |
Document, Report, or Work plan Review - other |
On October 7, 2015 a test pit was dug near the former dispenser island along Spenard Road and soil samples were collected to help assess for contamination in that area. Two soil samples were collected from the excavation (plus one duplicate) and two soil samples were collected from the excavated soil (3 cubic yards). The excavation samples had up to 4.1 mg/kg GRO, 39 mg/kg DRO, 250 mg/kg RRO, 0.008 mg/kg benzene, 7.8 mg/kg lead, 0.011 mg/kg phenanthrene, 0.013 mg/kg fluoranthene, and 0.01 mg/kg pyrene. The other VOCs, PAHs, and EDB were non-detect. The two stockpile samples were both below migration to groundwater cleanup levels and that soil was used as backfill in the trench excavation. |
Robert Weimer |
| 12/23/2015 |
Document, Report, or Work plan Review - other |
On October 29, 2015 two soil borings were sampled. Boring 1 was placed near the east end of the closed in-place USTs and Boring 2 was placed near the location of the 2014 closure sample 03. In both soil borings groundwater was found at 13.5 feet below ground surface (bgs). Each boring was sampled at 10'-11.5' bgs and at the soil/water interface. The samples had up to 24 mg/kg GRO, 19 mg/kg DRO, and 130 mg/kg lead. The detectable VOCs and PAHs were below cleanup levels. EDB samples were non-detect. |
Robert Weimer |
| 6/22/2016 |
Site Visit |
Site visit to check on current site conditions. |
Robert Weimer |
| 6/9/2017 |
Document, Report, or Work plan Review - other |
June 27-28, 2016 semi-annual groundwater monitoring by Chevron's consultant, which includes 8 monitoring wells currently being monitored on the Thrifty property. Up to 56.0 mg/l GRO, 6,500 ug/l toluene, and 620 ug/l benzene. The highest concentrations were on the Thrifty property. Concentrations increased in 4 of the 8 monitoring wells sampled on the property. Groundwater flowed to the southwest this monitoring event. Groundwater flowed to the south west this monitoring event. Depth to groundwater was 11.36 to 13.15 feet below ground surface. Samples were collect by no-purge method using Hydrasleeves. Samples were collected at the top of the water column. |
Robert Weimer |
| 6/15/2017 |
Document, Report, or Work plan Review - other |
September 13-14, 2016 semi-annual groundwater monitoring by Chevron's consultant, which includes 8 monitoring wells currently being monitored on the Thrifty property. Up to 78.0 mg/l GRO, 6,000 ug/l toluene, 3,200 ug/l ethylbenzene, 14,000 ug/l xylenes, and 520 ug/l benzene. The highest concentrations were on the Thrifty property. Concentrations increased in 4 of the 8 monitoring wells sampled on the property. Groundwater flowed to the southwest this monitoring event. Depth to groundwater was 10.98 to 12.85 feet below ground surface. Samples were collect by no-purge method using Hydrasleeves. Samples were collected at the top of the water column except for monitoring well MW-27. |
Robert Weimer |
| 1/16/2018 |
Document, Report, or Work plan Review - other |
September 11-13, 2017 semi-annual groundwater monitoring by Chevron's consultant. Up to 44 mg/l GRO, 3,800 ug/l toluene, 2,000 ug/l ethylbenzene, 10,000 ug/l xylenes, 2 ug/l MTBE, 5 ug/l 1,2-DCA, and 410 ug/l benzene. Concentrations increased in 4 of the 8 monitoring wells sampled on the Thrifty property. One of the monitoring wells (MW-27) was sampled for PAHs and had up to 36 ug/l Naphthalene, 0.33 ug/l Flurene, 0.67 ug/l Phenanthrene, 0.11 ug/l Acenaphthene, and 0.014 ug/l Acenapthylene. Groundwater flowed to the south west this monitoring event. Depth to groundwater was 10.89 to 12.72 feet below ground surface. Samples were collect after purging with a bladder pump at the top of the water column. |
Robert Weimer |
| 4/11/2019 |
Document, Report, or Work plan Review - other |
May 16-18, 2018 semi-annual groundwater monitoring by Chevron's consultant. Up to 88 mg/l GRO, 7,400 ug/l toluene, 3,800 ug/l ethylbenzene, 20,000 ug/l xylenes, 1 ug/l MTBE, 5 ug/l 1,2-DCA, and 460 ug/l benzene. Concentrations increased in 3 of the 9 monitoring wells sampled on the Thrifty property. Four of the monitoring wells were sampled for PAHs and had up to 110 ug/l Naphthalene (1.7 ug/l cleanup level). The other detected PAH compounds were below current cleanup levels. Groundwater flowed to the south west this monitoring event. Depth to groundwater was 10.97 to 12.79 feet below ground surface. Samples were collect after purging with a bladder pump at the top of the water column. Naphthalene results were missing from the VOC 8260 analysis. |
Robert Weimer |
| 5/16/2019 |
Document, Report, or Work plan Review - other |
September 26-28, 2018 semi-annual groundwater monitoring conducted by Chevron's consultant. Up to 77 mg/l GRO, 12,000 ug/l toluene, 3,800 ug/l ethylbenzene, 20,000 ug/l xylenes, 1 ug/l MTBE, 5 ug/l 1,2-DCA, and 800 ug/l benzene. Concentrations increased in 5 of the 10 monitoring wells sampled. Seven of the monitoring wells were sampled for PAHs and had up to 120 ug/l Naphthalene (1.7 ug/l cleanup level). The other detected PAH compounds were below current cleanup levels. Groundwater flowed to the south west this monitoring event. Depth to groundwater was 10.96 to 12.81 feet below ground surface. Samples were collect after purging with a bladder pump at the top of the water column. Naphthalene results were missing from the VOC 8260 analysis. |
Robert Weimer |
| 1/10/2020 |
Document, Report, or Work plan Review - other |
May 8-10, 2019 semi-annual groundwater monitoring conducted by Chevron's consultant. Up to 33 mg/l GRO, 4,200 ug/l toluene, 1,900 ug/l ethylbenzene, 11,000 ug/l xylenes, 0.7 ug/l MTBE, 5 ug/l 1,2-DCA, and 500 ug/l benzene. Concentrations increased in 3 of the 10 monitoring wells sampled on the Thrifty property. Some of the monitoring wells were sampled for PAHs and had up to 23 ug/l Naphthalene (1.7 ug/l cleanup level). The other detected PAH compounds were below current cleanup levels. Groundwater flowed to the south west this monitoring event. Depth to groundwater was 11.26 to 13.03 feet below ground surface. Samples were collect after purging with a bladder pump. Since the samples were not collected at the top foot of the water column as required the results may be biased low. Naphthalene results were missing from the VOC 8260 analysis despite it being requested on COC. |
Robert Weimer |
| 3/11/2020 |
Exposure Tracking Model Ranking |
A new updated ranking with ETM has been completed for source area 79774 Two 1,000-Gallon Gasoline USTs 3 & 4. |
Robert Weimer |
