FORMER WOOD TREATING SITE CORRECTIVE MEASURES IMPLEMENTATION
ENTACT implemented corrective measures at a 52-acre former wood-treating facility that produced creosote-treated railroad crossties. We installed a 2,200 linear foot soil-bentonite slurry wall to a depth of 45 feet below surface grade and permeability of 1×10-7 cm/sec to contain the source area and control groundwater migration from it. ENTACT also excavated and consolidated 17,000 cubic yards of polycyclic aromatic hydrocarbon and phenol-impacted surface soils, subsurface soils, and sediments and dewatered and backfilled a former water supply pond located in
PICKLE POND REMEDIAL AND HABITAT CONSTRUCTION
Pickle Pond is a nine-acre urban pond created by the construction of a railroad embankment that cut off part of Barker’s Bay. The pond is in the St. Louis River lower estuary, sheltered from the main bay, and provides habitat to waterfowl, beavers, otters, and other wildlife. White Lake Dock & Dredge, Inc., a division of ENTACT, LLC, was responsible for dredging more than 16,000 cubic yards of contaminated sediments consisting of fine-grained silty clays from a shallow draft area
FORMER CHROMIUM ALLOY AND RADIOLOGICAL SUPERFUND SITE
ENTACT was engaged to perform a four-phased remedial action project to support the decommissioning of this former glass and super alloy additives manufacturing facility. Due to historical and metallurgical operations conducted at the site, metals and radiological impacts were present in soil and sediment on the property and off-site, consisting of wetlands, a stream channel, and wooded upland areas. Phase 1 of the project addressed the impacted materials on the property limits, and Phases 2, 3, and 4 addressed the
CHEMICAL/ RADIOLOGICAL REMEDIATION AND WETLAND RESTORATION
ENTACT is performing an ecological restoration of 100+ acres, including creating a 14-acre open-water pond, 40 acres of wetland mitigation, 55 acres of upland enhancement, and close to two miles of public walking trails and boardwalks. We have completed the first two phases and are working on the third one. The first phase was the remediation of impacted sediments from a 4.9-acre lake on the site. Lake sediments ranged from 0.5 to 7 feet and were underlain by a continuous
ACTIVE STEEL MILL CREEK AND DITCH PCB SEDIMENT REMOVAL
ENTACT partnered with our Client to implement a phased solution to remove the impacted sediment and restore the river and its surroundings for a nearby community. Work included remediating 3,000 linear feet of ditch line and 5,600 linear feet of creek channel; transporting 178,500 tons of polychlorinated biphenyl-impacted sediment, clay, and native materials off-site for disposal; and treating and filtering 4 billion gallons of water using an onsite water treatment system. In addition to meeting our Client’s objectives, we managed
FORMER PHOSPHATE FERTILIZER SITES REMOVAL ACTION
ENTACT performed remediation of nine former phosphate fertilizer production and manufacturing sites to address lead- and arsenic-impacted soils, sediment, and groundwater. ENTACT partnered with our Client to navigate the complexities and requirements of this multi-facet remediation project. Sites were in commercial, residential, and industrial zones. Tidally influenced areas were located adjacent to navigable waterways, marshes, uplands, and active rail lines and major highways. While scopes varied in magnitude at each site, work typically involved excavation and off-site disposal activities, sediment
AGGREGATE MINER AND SUPPLIER SLURRY WALL PROGRAM
ENTACT originally served this major aggregate miner and supplier by replacing a cutoff wall over 9,000 feet high. This successful job and the relationship formed during the project established ENTACT as the Client’s dedicated slurry wall contractor. Following the successful completion of the first project, we constructed a 7,438-foot-long, 30-inch-wide soil-bentonite slurry wall to minimize dewatering efforts and facilitate dry mining operations. In addition to constructing a new slurry wall, our responsibilities included identifying and protecting many subsurface utility lines
TAR PONDS AND COKE OVENS SITE SOLIDIFICATION AND STABILIZATION
The tar ponds were filled with waste from a steel mill and coke oven, transforming the nearby tidal estuary with impacted sediments and sludge. The governments of Canada and Nova Scotia announced a plan to clean up the site and establish Open Hearth Park, a community gathering place. ENTACT developed solidification and stabilization mix designs in our treatability lab and confirmed the recommended formula through a successful field pilot program. We solidified and stabilized approximately 745,000 cubic yards of impacted
WET ASH IMPOUNDMENT CLOSURE
ENTACT completed the closure of a 140-acre wet fly ash impoundment containing approximately 13.4 million cubic yards of coal combustion residual (CCR). The project required draining the surface water via pumping and temporary drainage channels in the deposited ash and directing it to an area behind the main dam where a permitted outfall was located. The overall scope of work for the project involved lowering the main dam, removing the saddle dam, and constructing a new spillway for both dams;
INTEGRATED ENERGY COMPANY KEY SUPPLIER PROGRAM
ENTACT regularly performs remedial construction, geotechnical construction, and civil construction activities throughout the U.S. and select international locations for a major integrated energy company. Our 20+ year relationship demonstrates our commitment and partnership to our Client. We work with the Client’s team, assisting with preliminary design evaluations, site engineering, remedy selection, and cost budgeting in the planning phase of its many projects. We perform safe, effective, and cost-sensitive solutions at active and closed refineries, terminals, retail sites, oil field production
FORMER WASTE OIL RECOVERY FACILITY NATIONAL PRIORITIES LIST (NPL) SITE
The NPL Superfund site required remediation and geotechnical construction services to remove contaminants impacting its 150 acres. The former waste oil recovery facility site included numerous aboveground storage tanks; two API separators; a large, elevated sludge impoundment; and a small cemetery. The location is bordered by a bay, a closed waste disposal site, a city landfill, and undeveloped marsh and wetlands. ENTACT implemented a phased approach to reduce the overall schedule, allowing construction to occur concurrently with design submittals and
FLY ASH IMPOUNDMENT CLOSURE AND DAM MODIFICATION
For this 300-acre wet fly ash impoundment closure, ENTACT conducted a multiyear phased approach for the project. Closure construction started with draining surface water via pumping or digging temporary drainage channels in the deposited ash to direct water to an area immediately behind the main dam. As we managed the surface water, we excavated the exposed fly ash and relocated and/or regraded the surface to meet subgrade elevations across the site. Work progressed from the highest to lowest elevations across