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1. Introduction
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1.1 Background
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Site Number: |
B4B8 |
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Contract Number: |
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D.O. Number: |
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Action Memo Date: |
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Response Authority: |
CERCLA |
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Response Type: |
Emergency |
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Response Lead: |
EPA |
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Incident Category: |
Removal Action |
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NPL Status: |
Non NPL |
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Operable Unit: |
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Mobilization Date: |
9/21/2010 |
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Start Date: |
9/21/2010 |
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Demob Date: |
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Completion Date: |
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CERCLIS ID: |
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RCRIS ID: |
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ERNS No.: |
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State Notification: |
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FPN#: |
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Reimbursable Account #: |
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1.1.1 Incident Category - Emergency
1.1.2 Site Description - Unmitigated methane which is congregating in utility boxes and sewer pipes discovered in Atlanta neighborhood.
1.1.2.1 Location - 241 Maynard Terrace, Atlanta, GA
1.1.2.2 Description of Threat - explosive
1.1.3 Preliminary Removal Assessment/Removal Site Inspection Results - Explosive vapors are detected subsurface and in the water meter boxes, cracks in concrete surrounding a relatively new (2007) town house development and surrounding soils throughout the property
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2. Current Activities
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2.1 Operations Section
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2.1.1 Narrative - ATL Fire requested federal assistance in identifying source and required action to mitigate explosive threat of uncontained methane gas emanating from subsurface of a residential development. Methane is theorized to be coming from unpermitted burial of organic debris prior to the development of the project.
2.1.2 Response Actions to Date - Unified Command ended at 1000 9/24/2010 and EPA, using CERCLA 104 response authorities took lead on the site response activities. EPA is still working closely with the City of Atlanta Fire Department and GA EPD. - Screened the interior of a total of 10 town homes at the request of owners/tenants for LEL, and VOCs (using FID); no LEL concentrations were identified and only 2 townhomes indicated elevated VOC readings:
- Unit 29: VOC readings up to 178 ppm in a crack on the floor (bottom level)
- Unit 30: VOC readings up to 137 ppm in a crack on the floor (bottom level)
- Used AreaRAE units to monitor shallow (approximately 4 feet deep) borings installed inside each water meter box in front of town home garages; readings exceeding instrument limits for LEL were detected at virtually all locations greater than 1 foot bgs and methane concentrations up to 12% were identified in the boreholes. No LEL readings detected in breathing zone.
- Collected 7 air samples (tedlar bags) on 9-23-10 for VOC analysis (methane not included because of laboratory limitations) – no detections were identified in laboratory results; samples were collected from the following locations:
- Water meter boxes in front of town home garages (Units 10, 30, 43)
- Sanitary sewer manhole in southeast corner of property
- Water meter box along sidewalk adjacent to Maynard Terrace SE
- Water vault box in northeast corner of property
- Gas check valve in northeast corner of property
- ER advanced 5 soil borings in the southern (undeveloped) portion of the property using a Geoprobe (borings indicated wood and organic debris from approximately 10 to 20 feet bgs); air monitoring of each boring conducted for percent methane in air using a LandTec GA 90 landfill gas analyzer:
- B-1: maximum concentration detected = 47% methane in air
- B-2: maximum concentration detected = 60% methane in air (vapors observed coming out of the PVC tubing)
- B-3: maximum concentration detected = 27% methane in air (piece of carpet observed at approximately 20 feet)
- B-4: maximum concentration detected = 16.9% methane in air
- B-5: maximum concentration detected = 55% methane in air (vapors observed coming out of the PVC tubing); GW at approximately 22 feet; piece of metal
- Collected 4 air samples (summa canisters) on 9-24-10 for VOC analysis (including methane) – analytical results expected on Monday 9-27-10); samples were collected from the following locations:
- A-08 collected from boring B-1
- A-09 collected from boring B-2
- A-10 collected from boring B-3
- A-11 collected from boring B-5
- ERM began installing PVC monitoring points throughout the site to depths of approximately 5 feet bgs – methane concentrations up to 70% were identified (highest reading in the eastern portion of the site (in undeveloped portion).
- ERM began distributing methane home monitors as part of the indoor air monitoring program
2.1.3 Enforcement Activities, Identity of Potentially Responsible Parties (PRPs) - EPA has been granted written access and has delivered a Federal Notice of Interest. EPA's ORC, RCRA and Superfund will be looking at appropriate measures to enforce removal activities.
2.1.4 Progress Metrics
| Waste Stream | Medium | Quantity | Manifest # | Treatment | Disposal | | | | | | | | | | | | | | | | | | | | | |
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2.2 Planning Section
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2.2.1 Anticipated Activities - EPA will work with GA EPD and the City of Atlanta Fire Department until the appropriate responsible party is identified and is capable of proceeding with the necessary removal actions to mitigate the threat to human health and the environment.
2.2.1.1 Planned Response Activities - EPA and START will resume monitoring activities Monday (9/27/2010) and will begin receiving results from the sampling efforts.
2.2.1.2 Next Steps - EPA working with GA EPD will continue to provide site over site during the enforcement process
2.2.2 Issues - Maintaining the indoor air monitoring program while the remedy is designed and implemented.
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2.3 Logistics Section
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No information available at this time.
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2.4 Finance Section
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No information available at this time.
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2.5 Other Command Staff
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No information available at this time.
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3. Participating Entities
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No information available at this time.
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4. Personnel On Site
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1 EPA (OSC) 1 EPA (CIC) 1 ATSDR 2 GA EPD 10+ City of Atlanta FD 7 EPA Contractors (2 START - Tetra Tech, 5 ERRS - ER) 5 PRP Contractors (ERM)
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5. Definition of Terms
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No information available at this time.
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6. Additional sources of information
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No information available at this time.
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7. Situational Reference Materials
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No information available at this time.
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