Geotechnical Construction

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

LNG EXPORT TERMINAL GROUND IMPROVEMENT

ENTACT performed soil improvement at this 1,000-acre site in preparation for the development of a Liquefied Natural Gas (LNG) export terminal. The project site is at an ideal location, situated on a ship channel that connects with the Gulf of Mexico. It features deep-water access, proximity to plentiful gas supplies, and ease of transport for buyers. The scope of work included soil improvement of 411,000 cubic yards of soft saturated clay to depths ranging from 4.0 to 8.5 feet, within

LNG LIQUEFACTION SOIL STABILIZATION

The Client’s project included expanding a liquefied natural gas (LNG) terminal to accommodate three LNG trains, a typical gas pretreatment unit, and a dock. Before construction could begin, the ground needed to be reinforced to support the complete turnkey LNG facility. ENTACT performed mass stabilization of over 2.3 million cubic yards of soft dredged sediment and fill soils. We accomplished in-situ stabilization with 16 excavators working atop timber mats, and the pneumatic delivery of Portland cement via custom-fabricated conveyance boxes.

LNG EXPORT FACILITY SOIL IMPROVEMENT

In preparation for future construction at this liquefied natural gas (LNG) export facility, ENTACT improved the soil in the expansion area to facilitate equipment access and support perimeter storm protection and levee system construction. ENTACT’s scope included soil improvement of approximately 1.7 million cubic yards of soft saturated dredged clay, filled to depths ranging from 3.0 to 6.0 feet within various areas of this site. We utilized Type I-II Portland cement to achieve a shear strength of 1,800 psf for

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

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

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

ACTIVE REFINERY PROCESS UNIT PROPOSED LOCATION

ENTACT Addresses Low-pH Soils At Refinery Caused By A Sulfuric Acid Spill 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

BROWNFIELD REDEVELOPMENT AREA REMEDIATION

ENTACT performed remediation activities at several blocks and lots at this site, representing a larger-area brownfield redevelopment project for future residences. Multiple industrial operations impacted the soil with the following contaminants of concern: polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs), polychlorinated biphenyls (PCBs), hexavalent chromium, chromium ore process residue (COPR), extractable petroleum hydrocarbon (EPH), pesticides, various metals and lead. Scope of work included design, procurement, and installation of a 1,600-linear-foot, 40-foot-deep permanent vertical hydraulic control system; dewatering, water treatment,

ACTIVE REFINERY TANK FOOTPRINT SUBSURFACE GROUND IMPROVEMENT

As part of a larger capital program, an active refinery sought to expand its footprint to accommodate 14 tanks and four pump pads. Before construction could start on the new structures, ENTACT performed subsurface soil treatment of soft saturated soils to minimize future tank foundations and pump pads settlement. The ground improvement treatment consisted of installing a series of 8-foot diameter soil-cement columns on an 11-foot by 11-foot grid underneath the planned footprint of each tank foundation. A series of