Waste Oil Pits NPL Site
ENTACT performed in-situ stabilization of 45,000 cubic yards of hydrocarbon sludges at this former waste oil pits site. Additional site activities included relocation of half-mile of an existing stream away from the former waste pits; excavation of 10,000 cubic yards of impacted sediments from within a cypress swamp; installation a 3,100 linear foot perimeter slurry wall up to 80-feet in depth; construction of an 11.5-acre RCRA compliant capping system over the entire site; installation of an extensive underdrain network which serves as a stormwater collection system; and installation of a gas collection system.

Stabilization Detail: ENTACT designed the reagent program and methodology and performed in-situ stabilization of 45,000 cubic yards of hydrocarbon sludges/sediments using a Lang Mixer to deliver an average unconfined compressive strength of 100 psi, a maximum permeability of 1 x 10-6 cm/sec, and significant SPLP leachability reduction (VOC's, SVOC's, PCB's, and metals) in the treated product as measured for the highest concentration of the most toxic components including Antimony, Cadmium, Lead, Bis(2-ethylhexyl)phthalate, and Aroclor. A TCLP extract concentration for Lead below the hazardous level of 5 mg/l was also achieved. ENTACT employed a slurried reagent application (Portland cement & water) in order to provide the best end product and to preclude the generation of VOC/SVOC emissions and airborne particulates, routinely observed in pneumatic applications. No airborne emission exceedences (perimeter or otherwise) of VOC's/SVOC's/PCB's/Particulates were observed throughout the entire process. In fact, the measurable VOC concentrations were so low that a PPE downgrade from Level C to Level D was made after continuous, integrated air monitoring.

City Park Site Remediation
ENTACT completed remedial activities at this city park that was built atop a former municipal landfill. Site activities included clearing and grubbing 27 acres; management of lead and pesticide impacted soils; dewatering, excavation, on-site stabilization, and off-site disposal of impacted pond sediments, and installation of 1,000 lineal feet of cut-wall at the pond; construction of a 27-acre landfill cover system and installation of over 10,000 lineal feet of leachate gas collection trenches; excavation, rerouting, lining (164,000 square feet of 30-mil polyethelene) and reconstruction of over 2,700 lineal feet of channel; construction of 16 limestone block drop structures; construction of storm water and waste water improvements; and restoration of the park with native grasses and plants.