The 8-acre Superfund Site is adjacent to a major river at an active petroleum storage facility. Envirocon performed remedial activities at the inactive terminal contaminated by tank bottom material, spent cracking and reforming catalysts, oil and water separator material, oil solids, demolition debris, and asphalt-containing soil.
- Installed 1,600 linear feet of 52-foot long sheetpile from barges on the nearby river to create four cofferdam sections
- Dewatered cofferdam sections and excavated 30,000 cubic yards of upland, bank, and river soils
- Stabilized lower river bank using common fill, geotextile, reactive core mat, gravel, bedding stone, rip rap, and topsoil along with wetlands plantings
- Constructed a 3,350-linear foot soil-bentonite slurry wall up to 35-feet deep to prevent future groundwater migration into the river
- Constructed final cap and restoration features that included soil, geotextile, granular clay layer (GCL), native fill, and asphalt in specific tank berm areas
The initial sheetpiled section had a high water recharge rate from the riverbank infiltration, and the 250-gallon per minute (GPM) water treatment system required in the initial design was not sufficient. Envirocon’s technical team evaluated water infiltration and proposed a solution, approved by the city, with a maximum discharge of 1,750 GPM that saved significant costs for the client.