TranslateEastern PA Manufacturing Facility
The site has historically had soil and groundwater impacted by the use of the degreasing agents, tetrachloroethene (PCE) and trichloroethene (TCE). The in-situ pilot injection program targeted these compounds and their anaerobic daughter products.
A total of 19 injections were made in May and June 2009 over 2 days using an infiltration gallery, direct push points, and a deep injection well targeting specific zones with a straddle packer. The injections were made at 55-70 feet bgs in the deep bedrock zone, at 3-7 feet bgs using the infiltration gallery, and at 8-12 feet bgs in the direct push area.
The injection program utilized direct-push technology to apply blue green algae and kelp, essential nutrients (o-PO₄⁺ and NH₄⁺), sodium sulfite, calcium propionate, yeast extract, zero-valent iron (ZVI), EHC, and hydrogen release compounds (HRC-X and HRC).
The objectives of the program were to establish and maintain a stable dissolved hydrogen level, provide micro-nutrients, maintain pH, provide for optimal competitive conditions for the desired microbial consortia while minimizing the impact to the day-to-day operations of the facility (U.S. Patent 7,129,388).
Blue green algae and kelps were added in conjunction with organic hydrogen donors to provide necessary volatile fatty acids, as well as essential vitamins and nutrients for biological activity.
Deep Well Results:
- Only 1,1-DCE above detection limit, below PA standard
- Downgradient well: 42% total CVOC reduction
- Large increases in volatile fatty acids and dissolved gases
Direct Push Area (MW-9):
- TCE: 99.99% reduction (24 mg/L to 4.6 µg/L)
- Total CVOC: 84% reduction
- Most immediate and dramatic results
Infiltration Gallery Area (MW-6S):
- 70% or greater CVOC reduction in most wells
- Biologically-dominated reductive dechlorination
