Scope included excavation, stockpiling, and reuse of over 75,496 cubic yards of overburden; on-site crushing and reuse of over 30,000 tons of concrete; excavation, stockpiling and off-site disposal via rail of 205,000 tons of petroleum impacted material; demolition of over 75,000 square feet of on-site structures; installation of an 8-inch water line; cleaning and removal or in-place abandonment of underground piping that ran through the site, as well as an additional 5 miles that ran beneath city streets to the formal terminals; management of recovered product; backfilling and restoration of city streets; and site backfill and restoration. Due to the proximity to the bay (more than 500 feet) and the depth of excavation (up to 21 feet bgs), a perimeter dewatering and sump system consisting of sixty-four (64) temporary dewatering wells and six (6) mobile sumps was installed around the perimeter of the excavation zone to minimize water infiltration. Over 48 million gallons of water was collected and treated for petroleum hydrocarbons and suspended solids at a rate of up to 1,000 GPM prior to discharge into the sanitary sewer.
Project scope includes the excavation, handling, transportation and disposal of 800,000 tons of PCB impacted materials and total material handling of over 1,200,000 tons. ENTACT is additionally responsible for the construction of a 40-acre onsite landfill. Other remediation activities include the complete excavation and restoration of ancillary runoff tributaries from the plant. Remediation activities include extensive construction of access/haul roads in and around creek and flood plain areas to enable ingress and egress to the removal areas; the construction of loadout areas ranging in size from 3.5 acres to 6.5 acres to expedite the transport of impacted material; and the construction of diversion channels, 2 miles in total length, to enable sediment removal from the creek bed and flood plain. Water management is a 24 hours a day, 7 days a week activity that includes containment and treatment of millions of gallons of water in contact with the impacted areas. Two (2) 1,000 GPM water treatment systems were designed and installed by ENTACT, and operated simultaneously. The systems involved initial settlement through an interconnected series of ten or more baffled 20,000 gallon frac tanks, skimmer removal of free product, polymer injection to promote settling, solids removal via sand vessels and bag filters, and removal of dissolved organics via carbon adsorption vessels.
