FPN: E043Z1
EPA Site ID: Z3GE
Response Authority: Clean Water Act §311
Removal Funding Authority: OPA 90
State Notification: Maryland Department of Environment
Date OSLTF Opened: 04/08/04
Mob Date: 04/09/04
Current Project Ceiling: $670,000
Demobilization Date: August, 13, 2013
Completion Date: September 23, 2014
Incident Category: Medium
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During this reporting period the Responsible Party submitted its Final Closure Report on August 29, 2014. This report provides specifics regarding all activities performed by the Responsible Party under Administrative Order on Consent (CWA -03-2005-0150CW) signed on April 28, 2005. Three areas of concern included soil contamination, presence and migration of free product and site recovery and restoration.
The area where the former AST (source) was located was reported to have been a ravine which had been backfilled over time with construction debris. Therefore bioventing of contaminated soils was selected as the remedy due to depth of contamination (up to 30ft bgs) and areal extent. The goal of the bioventing was to introduce air into the subsurface to enhance microbial degradation of the petroleum hydrocarbons. This approach was largely successful however elevated levels of TPH DRO remain. Due to the depth, 15 to 30 ftbgs of these pockets of contamination it is assumed that threat to health and welfare of people is minimal. However the bioventing process will continue under the oversight of the Maryland Department of the Environment. Oversight by EPA will no longer be required.
Free product recovery occurred, under this order, at the nearby unnamed creek. A total of 4561 gallons of diesel fuel was recovered thru product recovery efforts at the seep area since this order was implemented. In addition various measures were implemented to protect any releases to the creek including the construction and maintenance of an underflow dam in the creek itself. As time elapsed less and less product accumulated in the sumps thereby indicating a drying out of the subsurface contamination to the point where after a few wet springs little to no product was collected. The OSC approved the Seepage Area Closure Report via email dated April 12, 2013. On August 13, 2013 the underflow dam was officially removed signifying site demobilization. However monitoring of the source area subsurface bioventing operation continued.
Site recovery and restoration included working with the property owner, EMA Inc. An Abatement Plan included the re-vegetation of the seep area with native trees via a two phased approach. The property owner, EMA was consulted and provided final approval on all work. In addition all wells, piezometers and sumps were removed and abandoned reports filed with MDE. All PVC associated with the recovery trench and materials associated with the underflow dam were removed. MDE has approved all abatement activities via its site status letter dated March 18, 2013.
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Actual product removal activities were terminated on August 13, 2013 when the underflow dam was removed. Total volume of product captured during this action is 4561 gallons of diesel. The total volume of contaminated water removed was 52,365 gallons.
Final site Closure Report was submitted to EPA dated August 29, 2014. Notice of Completion letter signed by the EPA OSC dated September 23, 2014.
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