About This Project
Abstract
Trap & Treat BOS 200® was used to remediate petroleum hydrocarbon impacted groundwater in shallow overburdened soil at a former retail gasoline site in Washington State. BOS 200® was surgically injected to successfully achieve the site cleanup goals. A No Further Action was issued in August 2017.
Challenges & Objectives
The site is a retail service station and convenience store. A release was discovered at the site in 1988 associated with the UST systems. Gasoline-range hydrocarbons were detected in soil exceeding the Model Toxic Control Act (MTCA) Method A Cleanup Levels (CULs) from nine (9) to 27 feet below land surface. Soils on-site have been identified as course-grained sands and gravels.
Project Snapshot
Key Dates
- Data analysis /design – (Fall 2013)
- Initial Injection of BOS 200® – (April 2014)
- 2nd Injection of BOS 200® – (January 2015)
- No Further Action – Washington DOE August 2017
- Treatment Areas (Total) – 1,145 sq. ft
- Depth to Groundwater – 8 to 19 feet BLS
- Contaminants – Gasoline-range hydrocarbons and associated constituents
Approach
Based upon historical analytical data, depths between 12 and 27n feet BLS were selectively targeted for treatment.
The selected technology for the remedial action was Trap & Treat BOS 200®. Four (4) areas of residual impact received a total of 34 injection points on 7.5 foot triangular-grid spacing. A second of in-situ BOS 200 injections was conducted near MW-9 on January 12, 2015. The second injection event specified an additional 10 injection points installed in the targeted area. The site met the requirements of Groundwater Model Remedies No. 5 and was issued a No Further Action in August 2017.
4,195 lbs BOS 200®, 2,150 lbs gypsum, 15 gallons of bacteria concentrate were applied to 44 injection points.
Reagent Price: $26,600
Results
Gasoline-range hydrocarbons were reduced by ∼77% immediately immediately following the initial injection. After a single sampling event spike in TPH-GRO, concentrations.