| Action Date |
Action |
Description |
DEC Staff |
| 4/1/2016 |
Update or Other Action |
Draft UFP-QAPP SC WP received for review and comment for several sites which also includes this one.
Site CG114 – 22nd Street is located on Joint Base Elmendorf-Richardson (JBER) at the former Elmendorf Air Force Base property (JBER-E), in Anchorage, Alaska. CG114 is located northeast of Site TU100, which is the former location of a steel, single-walled, 250-gallon regulated underground storage tank (UST 911) that contained diesel fuel (Figure 1). During the 2013 TU100 site investigation, a possible upgradient petroleum source area was identified and is being investigated as Site CG114.
Soil samples for TU100 were analyzed for GRO, DRO, RRO & PAHs for soil and DRO, BTEX for groundwater.
Soil borings will be drilled and soil samples will be collected from each of the borings at CG114.
Groundwater samples will be collected at three of the boring locations. One suspected source area boring (CG114-SB01) will be drilled in the known contaminated area near previous sample location 13TU100-SB11 to collect soil samples for gasoline-range organics (GRO), diesel range organics (DRO), residual-range organics (RRO), volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), volatile petroleum hydrocarbon (VPH), extractable petroleum hydrocarbon (EPH), and lead analysis.
Four soil borings (CG114-SB02, CG114-SB03, CG114-SB04, and CG114-SB05) will be drilled northwest, southeast, southwest, and northeast of the suspected source area to evaluate the lateral and vertical extent of contamination. Samples will be analyzed for GRO, DRO, RRO, petroleum-related VOCs, PAH, and lead.
Groundwater samples will be collected from the source area boring CG114-SB01, and the borings
southwest and northeast of the source area boring (CG114-SB04 and CG114-SB05), to investigate if
groundwater has been affected.
Groundwater samples will be analyzed for GRO, DRO, RRO, petroleum-related VOCs, PAHs, and lead.
Groundwater samples from within the expected source area will also be analyzed for the full suite of VOCs, EPH and VPH. The results of the groundwater sample analyses will determine if monitoring well installation is necessary.
See site file for additional information. |
Louis Howard |
| 4/11/2016 |
Site Added to Database |
A new site has been added to the database |
Mitzi Read |
| 4/13/2016 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed for source area id: 79902 name: CG114 22nd Street |
Louis Howard |
| 9/21/2017 |
Update or Other Action |
Site characterization report received for review & comment. The unknown DRO source identified during the 2013 TU100 investigation at soil boring 13TU100-SB11 was further investigated & the location of the source area was confirmed. The highest DRO at CG114-SB01 was in the surface, between 0 & 5 feet bgs at 19,000 milligrams per kilogram (mg/kg). DRO was also above the screening level from 5 to 10 feet bgs at 500 mg/kg, & from 10 to 15 feet bgs at 1,000 mg/kg.
Based on the results from borings surrounding CG114-SB01, the DRO contamination does not cover a large area, & for purposes of assessing risk from the site, the horizontal & vertical extent of DRO in soil has been delineated. Based on data collected in 2016, the soil source area (defined as the 3D soil volume with DRO greater than 250 mg/kg) begins at approximately ground surface (0 feet bgs), extends vertically to approximately 15 feet bgs, & covers an area approximately 22 by 30 feet (for an approximate volume of 9,900 cubic feet, or 370 cubic yards).
Using the ADEC Petroleum Cleanup Levels Calculator for contaminated soil, DRO does not meet Method Three criteria for ingestion & migration to groundwater. DRO also exceeds the ADEC Table B2 maximum allowable concentration. Therefore, DRO is a COC in soil.
Using the ADEC Cleanup Levels Calculator for contaminated soil, naphthalene does not meet the Method Three criteria for migration to groundwater & is a COC in soil. Because concentrations exceeds the minimum ADEC Method Two CULs, naphthalene is also a COC because of potential risk to future receptors through the vapor intrusion pathway.
DRO was not detected in the three groundwater samples collected. PAHs were not detected in groundwater samples either.
See site file for additional information. |
Louis Howard |
| 10/11/2017 |
Document, Report, or Work plan Review - other |
Staff commented on the draft site characterization report. The main comments were regarding updating the cleanup levels to reflect current ADEC 18 AAC 75 and the June 2017 EPA soil regional screening levels (RSLs). Finally, comments were made regarding the rejection of EPA's 2002 guidance document and the approach for statistically calculating groundwater exposure point concentrations using the upper confidence limit. Regulations require compliance with groundwater cleanup levels be based on the maximum detected level of contamination in groundwater and not based on statistics which are appropriate for trend concentration reviews. Staff concurred with the recommendation to excavate until soil cleanup levels are met to obtain a cleanup complete determination per 18 AAC 75.380(d)(1).
See site file for additional information. |
Louis Howard |
| 11/15/2019 |
Update or Other Action |
Draft decision document received which identifies dig and haul of diesel range organic contaminated soil above 10,250 mg/kg for treatment/disposal. No other contaminants were identified in soil or groundwater. There are no detected contaminants in groundwater.
See site file for additional information. |
Louis Howard |
| 1/8/2020 |
Document, Report, or Work plan Review - other |
Staff commented on the draft decision document for remedial action. Petroleum-related polynuclear aromatic hydrocarbons (PAHs) which exceed the migration to groundwater (MTGW), but fail to exceed the EPA regional screening levels (RSLs), should be carried forward as contaminants of potential concern. Especially since this is a State regulated petroleum site, the Air Force shouldn't be off-ramping anything because of how it compares to the EPA RSLs where exceedances of the promulgated MTGW cleanup levels as listed in 18 AAC 75.341(c) Table B1 Method Two – Soil Cleanup Levels Table.
ADEC expects that in addition to comparing to EPA RSLs, that soil results will be compared to 1/10 the Table B 1 Method Two human health soil cleanup levels or MTGW soil cleanup levels, whichever is most stringent. This will determine if additional action must be considered under state law for CG114. The remedial action objective needs to be: “reduce contaminant concentrations to the migration to groundwater (MTGW) cleanup level or an alternative cleanup level developed in accordance with 18 AAC 75.
See site file for additional information. |
Louis Howard |
| 4/12/2021 |
Document, Report, or Work plan Review - other |
DEC submitted comments on Draft JBER Basewide UFP-QAPP dated February 2021. |
William Schmaltz |
| 5/19/2021 |
Document, Report, or Work plan Review - other |
DEC Reviewed and approved of Basewide Uniform Federal Policy - Quality Assurance Project Plan. QAPP summarizes general activities for a 5 year period on JBER. |
William Schmaltz |
| 10/8/2021 |
Document, Report, or Work plan Review - other |
DEC provided comments on CG114 Draft Remedial Action Work Plan. |
William Schmaltz |
| 12/1/2021 |
Site Characterization Workplan Approved |
DEC reviewed and approved Final CG114 - 22nd street Remedial Action Work Plan. The work plan describes steps and processes to be conducted to excavate soil with DRO concentrations greeter than 250 mg/kg, the collection of soil confirmation samples from the associated excavation, and the associated disposal of DRO-contaminated soils at site CG114 located at Joint Base Elmendorf-Richardson (JBER). |
William Schmaltz |
