With a 40-year history of treating railroad ties with coal tar creosote, it was no surprise for the United States Army Corps of Engineers when studies revealed extensive levels of creosote contamination in the soil and groundwater at the GCL Tie and Treating Superfund site. Conti Federal's innovative approaches to excavation and groundwater management resulted in no lost time and cost savings of more than $250,000 despite increased quantities of soil requiring treatment.Back to All
The unconsolidated and bedrock aquifers were impacted with creosote including a large plume of DNAPL and bordering presence of dissolved BTEX and PAH compounds.
Conti Federal constructed and operated groundwater treatment at the Superfund site, including soil cleanup at Operable Unit 1 and groundwater cleanup at Operable Unit 2. Conti Federal successfully designed and built a 100 gallon per minute groundwater treatment system and appurtenances necessary for plume capture and regulated treatment. The team installed treatment components, such as DNAPL and oil-water separators, bag filters, an air stripper, vapor granular activated carbon (GAC), chemical feed and pH control, green sand filters and a liquid GAC filtration, in addition to removing sludge and sediment. Conti Federal developed and installed eight overburden and bedrock groundwater extraction wells. The team performed aquifer pumping tests, including step-drawdown tests and constant rate tests to determine pump sizing, hydrologic influence and plume capture. Initial investigations estimated 22,000 tons of impacted soil required treatment, however, when contaminated soil was discovered at increased depths, those quantities increased to 82,000 tons.
Conti Federal implemented a comprehensive Safety and Health Program for this project resulting in zero lost time accidents over two years of site work and heavy winter operations.
Key features of the project included: