| Action Date |
Action |
Description |
DEC Staff |
| 7/23/2010 |
Document, Report, or Work plan Review - other |
ADEC received the Class V Injection Well Sampling ADOT&PF Maintenance Facilities, Various Locations submitted by Shannon & Wilson and dated July 23, 2010. This report discusses preliminary sampling at multiple DOT maintenance shops including Chulitna, Homer, and Silvertip. Two discharge points were evaluated at Chulitna and Homer while only one discharge point was evaluated at Silvertip. The depth of borings ranged as follows: 10 feet Silvertip (two soil samples collected at 8 to 10 feet bgs), 20 feet Chulitna (soil samples collected at 13 to 15 feet bgs and 18 to 20 feet bgs), and 11 feet Homer (soil samples collected 4.5 to 6.5 feet bgs and 7 to 9 feet bgs). Soil samples were analyzed for VOCs, SVOCs, and metals. Silvertip, Chulitna, and Homer all contained Chromium and arsenic above clean up levels(which could be attributed to background). Silvertip did not contain any other contaminant concentrations above cleanup levels. Chultina contained naphthalene up to 0.830 mg/kg, 1,2,4-trimethylbenze up to 1.51 mg/kg, 1,3,5-trimethylbenzene up to 1.51 mg/kg, and 2-methylnaphthalene up to 8.67 mg/kg above cleanup levels. Homer contained TCE up to 0.0626 mg/kg above the cleanup level. |
Grant Lidren |
| 6/15/2016 |
Update or Other Action |
On this date, ADEC received the “CLASS V INJECTION WELL CLOSURE REPORT CHULITNA MAINTENANCE STATION” submitted by R&M dated June 2016. The Class V injection well seepage pit which was located approximately 6 to 7 feet bgs. The top of the seepage pit was approximately 7 feet bgs and the bottom was approximately 15 feet bgs. The Class V injection well consisted of the cast iron pipe feeding into an 8-foot by 8-foot by 8-foot deep spruce-log crib topped with decking boards, plastic foam insulation, and plywood. Soil removed from the pipe run and from above the seepage pit did not have observed odor or soil discoloration. Soil from the bottom of the seepage pit to the bottom of the excavation (15 to 26 feet bgs) had a strong petroleum or solvent odor along with distinct soil discoloration. Typically, site soils were brown to grayish brown and soils from around and below the seepage pit were gray to metallic gray. A heavy, iridescent petroleum sheen was observed on groundwater, which was encountered at 24 feet bgs. Excavation was limited vertically (26 feet bgs) by the reach of the excavator and the presence of groundwater which caused the excavation side walls to begin caving. Elevated field screening results were detected in the seepage pit excavation to the final depth reached. Based off the presence of contamination, two trenches were extended 12 feet from the south and west sides of the seepage pit excavation to determine lateral extent of elevated pid readings and visual and olfactory presence of contamination. The south trench was advanced 15 to 17 feet bgs, the west trench was advanced 21 feet bgs. Soil was segregated into cell C for presumed clean soil and cell D was for presumed dirty soil based off location to the UIC and elevated field screen results. Stockpile D contained contaminant concentrations above cleanup levels, however stockpile C did not. A total of 10 soil samples were collected. Soil samples collected from the discharge point at 15 feet bgs contained benzene up to 0.151 mg/kg, 1,2,4-trimethylbenzene up to 40.8 mg/kg, 1,3,5-trimethylbenzene up to 23.5 mg/kg, 1-methylnapthalene up to 95.7 mg/kg, 2-methylnapthalene up to 106 mg/kg, bis(2-ethylhexyl)phthalate up to 42.7J mg/kg, napthalene up to 37.4J mg/kg, PCE up to 0.0162J, arsenic up to 28 mg/kg, cadmium up to 33.2 mg/kg, lead up to 1,080 mg/kg and chromium up to 223 mg/kg. Soil samples collected from the bottom of the seepage pit at 26 feet bgs and the northeast excavation sidewall at 18 feet bgs contained DRO between 4.090 mg/kg and 5,030 mg/kg. |
Grant Lidren |
| 6/28/2016 |
Site Added to Database |
A new site has been added to the database |
Mitzi Read |
| 12/8/2016 |
Update or Other Action |
On this date, ADEC received the Stockpiled Soil Sampling and Analysis Report Chulitna Maintenance Shop submitted by Nortech, dated December 5, 2016. A total of eight soil samples were collected from Stockpiles C (118 cy) and D (140cy). Soils samples from stockpile D contained contamination above ADEC 2016 cleanup levels including hexavalent chromium up to 0.35J, DRO up to 9,600 mg/kg, RRO up to 16,700 mg/kg, and xylenes up to 3.07 mg/kg. Soils samples collected from stockpile sample C contained detectable levels of contaminants but below cleanup levels. Note: these soils samples were only analyzed for GRO, DRO, RRO, BTEX, TCLP metals, TCLP VOCs, and Cr6+. |
Grant Lidren |
| 1/12/2017 |
Update or Other Action |
On this date, ADEC sent a Compliance Letter to DOT. This letter was sent to DOT due to work being completed without approved work plans for both Chulitna (file: 2269.38.0053) and Silvertip (file: 2315.38.004) Class V Injection Wells and due to the transport of stockpiles without EPA or ADEC approval at the Quartz Creek Injection Well (file: 2308.38.005). |
Grant Lidren |
| 3/14/2017 |
Update or Other Action |
On this date, EPA closed the injection well |
Grant Lidren |
| 7/11/2017 |
Update or Other Action |
The clean stockpile C was land spread on site to fill in the low spots. |
Grant Lidren |
| 11/2/2017 |
Update or Other Action |
On this date, ADEC received an email from DOT with Disposal tickets for Chulitna Station Contaminated Soil (assumed stockpile D). This soil was disposed of at the Columbia Ridge Landfill in Oregon. However, ADEC never received/approved an approval to transport form for these soils from the Chulitna Maint. Station to Columbia Ridge Landfill. |
Grant Lidren |
| 11/28/2017 |
Offsite Soil or Groundwater Disposal Approved |
On this date, ADEC post approved transport of soils. On November 2, 2017, DEC received disposal tickets. the soil was transported by NRC and disposed of at the Columbia Ridge Landfill in Oregon. |
Grant Lidren |
| 1/16/2019 |
Update or Other Action |
On this date, DOT confirmed the onsite drinking water well located on the east side of the building is used for non-potable uses. The Maintenance Station is supplied with bottled water for drinking. The drinking water well was sampled in 2008 and 2010 with results below Table C Groundwater Cleanup Levels. |
Grant Lidren |
| 7/11/2024 |
Site Characterization Workplan Approved |
Approved workplan for contaminated site characterization through installation of monitoring wells and soil borings. |
Michael Hooper |
| 2/24/2025 |
Site Characterization Report Approved |
Approved report. Site characterization occurring in 2024 indicates that contamination has reached the groundwater table near the former UIC. Down-gradient monitoring wells were below the cleanup levels. DEC Agreed with recommendation to conduct additional groundwater monitoring in the future. |
Michael Hooper |
| 4/24/2025 |
Site Characterization Report Approved |
Reviewed Groundwater Monitoring report. Diesel range organics, residual range organics, and naphthalene exceed the cleanup levels near the former injection well. DEC agrees with the recommendation for additional groundwater monitoring in three years time. At the time of the next monitoring event a groundwater gradient should be calculated. |
Michael Hooper |
