• Cofferdams
• Retaining Walls
• Containment Walls
• Cut and Cover Tunnels
• Bulkheads and Seawalls
• Weir Walls
• Baffle Walls

• An excavation is not required, which minimizes waste disposal problems;
• Sheet piling can be removed later, if required or desired;
• Topography and depth to groundwater have little impact;
• Irregular enclosure shapes are possible; and
• Sheet piles can be installed off barges, which eliminates unnecessary site clearing.

Case Studies
GROUNDWATER CONTROL BARRIER
UNOCAL NORTH AREA CLOSURE
Nederland, Texas

• RECON utilized an excavator mounted on swamp pontoon tracks to install several drainage ditches in excessively soft sediment/ sludge. This coupled with simple sump dewatering techniques proved to lower the water elevation in the sludge, forming a two-foot thick crust. This allowed low-ground pressure dozers to traverse most of the area. Other very soft areas within the impoundment were stabilized using fly ash, a by-product generated from a local power plant. Long-stick excavators were used to mix the fly ash with the sludge. By excavating drainage ditches, RECON used 50% less fly ash during the project. In addition, we were able to use normal strength bi-axle geogrid in lieu of high-strength.
• Clean sand was to be placed above geogrid for purposes of serving as a pressure-relief layer and GCL bedding layer. Since the drainage ditches were installed, sand was no longer required to serve as a pressure-relief layer. RECON substituted a more readily available sandy clay [60-40] material in place of the sand. RECON crews installed both geogrid and GCL.
• In order to speed-up the construction schedule to receive a minimum of 200 loads of dirt per day, RECON developed and operated a borrow pit and purchased 17 dump trucks. With the help of local hauler, RECON was able to haul in excess of 400 loads per day to UNOCAL.
• Last but not least, our field crews make the difference. Much of our success on this UNOCAL project was directly attributed to their ingenuity and willingness to get the project done in a safe and quality manner, productively.

Case Studies
UNOCAL TANK FARM
Santa Fe Springs, California

Remedial Construction Services, L.P. (RECON) was retained by Bryan A. Stirrat & Associates to install a vertical barrier at the former Unocal Tank Farm facility, located in Santa Fe Springs, California. The vertical barrier was intended to mitigate offsite vapors from moving on the site, due to influences from an in-situ vapor extraction project that was occurring at the former Tank Farm.

The barrier was approximately 300 feet long, at a vertical depth of roughly 30 feet below grade. The barrier was a combination of soil-bentonite slurry wall construction and vinyl sheeting.

Soil conditions indicated that most of the soil along the creek was sand to the planned depth of the piling installation. Soil borings indicated a clay layer was available for keying into, at a range from 18 to 24 feet deep.

CONFIDENTIAL CLIENT
Sabine Dock Texas