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;
PCB SITE RESIDENTIAL REMEDIATION AND RESTORATION
This active industrial facility’s surrounding area contained polychlorinated biphenyls (PCBs) that needed to be removed because of nearby residential and community spaces. ENTACT used its residential remediation expertise to develop a field approach that prioritized the community’s safety, communication with the impacted neighbors, and an efficient schedule to complete this multiyear remediation and restoration project. Site activities included remediation and restoration of 676 PCB-impacted residential properties; transportation and placement of removal soils to either an onsite staging area or an
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 MGP SITE
ENTACT implemented in-situ solidification and stabilization at this former manufactured gas plant (MGP) to address the impacted materials. Through two phases of work, we successfully managed environmental conditions and prepared the site for redevelopment, while meeting our Client’s schedule and budget objectives. ENTACT performed various activities, including demolition and removal, off-site disposal and recycling of building slabs and subsurface structures. We performed collection, management, treatment and discharge of MGP contact water; removal, reinstallation or protection of utilities; plugging and grouting
FORMER FACTORY REMEDIATION AND REDEVELOPMENT
ENTACT remediated a former factory site – slated for residential and retail redevelopment – that was impacted by multiple contaminants, including arsenic and lead. The property is in a dense urban area, divided by a city street and bordered by city transit and right of ways (ROWs). The scope of work included onsite treatment and off-site disposal of 44,000 tons of non-hazardous material; onsite stabilization and off-site disposal of arsenic, volatile organic compound, and contaminant-impacted soils as much as 16 feet
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
INDUSTRIAL COMPLEX REMEDIATION AND REDEVELOPMENT
ENTACT performed remedial activities at this 2,200-acre industrial complex in preparation for mixed-use redevelopment. Using our internal technical and treatability skills, we developed a remedial solution to reduce the site’s high moisture levels to target objectives. This process included geotechnical evaluations, soil mixing, free draining, dewatering, and reagent evaluations of source materials. We performed critical items concurrently throughout our phased, multiyear site approach to maintain an efficient schedule. Major scope items included the removal of 3.9 million cubic yards of
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
ACTIVE REFINERY PROCESS UNIT PROPOSED LOCATION
ENTACT performed soil remediation and ground improvement to address low-pH soils because of a sulfuric acid spill at the refinery. The ground needed to be stabilized to support the construction of a new process unit at the site. Subsurface soils consisted of saturated, soft, and sandy clay on top of very soft clay. ENTACT performed ISS on approximately 86,000 cubic yards from 22 to 24 feet below ground to strengthen this area. Using a combination of granulated ground blast furnace
FORMER WOOD PRESERVING SITE REMEDIAL ACTION
This 84-acre wood preserving site was added to the National Priorities List in 1997, due to contaminated groundwater, soil, and sediment from over 30 years of wood treating operations. While multiple cleanup phases had occurred over the years, the prior remedy was deemed inadequate, and ISS was selected as the revised remedy. The scope of work included conducting an ISS demonstration before full-scale implementation; removing, stockpiling, and replacing clean, overburden soils; ISS of 15,400 cubic yards of non-aqueous phase liquids