Single Auger Mixer (8 feet to 14 feet)
Blending Rakes (6 feet to 15 feet lengths)
Pugmill (up to 75 tons per hour)
Bucket Mixing (RECON owns 21 excavators)

RECON uses the mechanical mixing tools listed above to combine chemical oxidants or stabilizing reagents with the contaminated medium. Stabilizing reagents are the most common because of the added benefit of solidification. Our experience has included the following reagents and oxidants:

Fly Ash
Fluidized Bed Ash
Cement or Cement Kiln Dust
Lime or Lime Kiln Dust
Blast Furnace Slag Cement
Potassium Permanganate
Chlorine

Triple Super Phosphate
Impermix Grout
Cement Based Grouts
Chemical Grouts
Muck Mix (Patented Reagent Blend)
Hydrogen Peroxide
Sodium Percarbonate

Additional information on the stabilization of sludge can be found at www.sludgestabilization.com

Solidification - StabilizationCase Studies

SLUDGE STABILIZATION
SWIB/WWTS CLEANOUT PROJECT
Norco, Louisiana

Remedial Construction Services, L.P. (RECON) was contracted by ERM EnviroClean-Southwest to solidify sludge from the Storm Water Impoundment Basin/Wastewater Treatment System (SWIB/WWTS) at the Shell Chemical Company/Motiva Enterprises Norco Manufacturing Complex in Norco, Louisiana.

Work consists of constructing a temporary earthen dam in the northern SWIB, dewatering the southern SWIB/WWTS and a portion of the northern SWIB/WWTS south of the temporary earthen dam, installing a silt curtain to contain solids during dewatering, raising the North Dike, solidifying sludge in the southern SWIB/WWTS, removing and backfilling piles from the sampling pier, and demolishing the cellular interlocking concrete block overflow weir and concrete wall.

The primary goal of the solidification project was to reconfigure the southern portion of the SWIB/WWTS into three inlet bays of roughly equal capacity. This was accomplished by solidifying the sludge insitu (approximately 35,000 cubic yards) from the base of the dikes using solidification reagents and using approximately 20,000 cubic yards of sludge to construct the two Separator Dikes to grade in the Southern SWIB/WWTS. Solidified sludge was also used to raise the elevation of the existing dike at the northern side of the Southern SWIB/WWTS (the North Dike) that divides the northern and southern portions of the SWIB/WWTS. The solidification reagents were injected into the sludge using excavator mounted injection rakes equipped with dust control misters.

RECON also constructed the access roads on top of the two separator dikes.

SURFACE IMPOUNDMENT CLOSURE
Edgemoor, Delaware

Closure of four surface impoundment ponds at a Delaware facility involved the neutralization and stabilization of 70,000 cubic yards of ferric chloride sludge. The pH of the waste material was less than two standard units, and in the case of one pond less than 0.5. The primary objective for Remedial Construction Services, L.P. (RECON) was to provide sufficient bearing capacity to support a geosynthetic cover system over the sludge material in the future. A second objective of the remediation program was to further control leaching of the impoundment material to ensure that contaminant levels were below the maximum levels mandated by the Federal Safe Drinking Water Act (SDWA).

Stabilization Program
The unconfined compressive strength (UCS) of the stabilized sludge was required to be 15 to 20 psi, in order to support a cap without deformation. To achieve this, as well as meet the leachate and toxicity requirements, RECON used a reagent composed of 20% hydrated lime, 10% Portland cement and 10% water. The dry reagent components were pneumatically discharged into dust suppressant devices. Where additional dust control was deemed necessary, lime slurry was used in lieu of hydrated lime, and discharged from tanker trucks. The reagent was then mixed with the sludge using a trackhoe.

Testing
During the work, samples of the treated material were retrieved and analyzed using the Toxicity Characteristics Leaching Procedure (TCLP), and the Synthetic Precipitation Leaching Procedure (SPLP) established by the EPA to determine contaminant migration levels in groundwater. Results confirmed that the neutralization and stabilization program had met both the RCRA toxicity characteristics requirements and the Federal SDWA acceptable contaminant levels.

In addition to the sludge remediation work, RECON installed a gravity drain system to allow rainwater from three ponds to collect in the fourth pond in preparation for channeling to the facility´s water treatment unit.

TEX TIN SUPERFUND SITE
Texas City, Texas

Remedial Construction Services, L.P.´s (RECON´s) closure of the Tex Tin Superfund site was being accomplished in five stages. Critical aspects of this extremely challenging project include:

Engineering/design of complex, site-wide remedy within 18 months of Notice to Proceed
Implementation of project using innovative staged approach
Management of over 1000 organic and inorganic waste streams
Compliance with stringent government reporting requirements

Stage 1: Demolition, debris disposal, lab packing, asbestos abatement, tank cleaning and demolition, and implementation of a storm water management system.

Stage 2: Management of more than 8, 000 drums and consolidation/stabilization of stockpiled materials, principal threat soils, and Wah Chang Ditch sediments.

Stage 3: Implementation of an acid water treatment system, solidification/stabilization of acid sludge, consolidation/stabilization of NORM and non-NORM slag, and backfill and impermeable capping of the acidic surface impoundment.

Stage 4: Consolidation/stabilization of all non-slag materials, installation of the barrier (slurry) wall, and backfill/compaction of the clay cover.

Stage 5: Backfill and compaction of all surface impoundments, installation of RCRA equivalent cap, capping of the NORM disposal cell, installation of evapotranspiration system, and installation of ground water monitoring system.

TEX TIN SUPERFUND SITE

Closure Specifics

Stabilization and consolidation of 6,500 drums of ash, catalyst and IDW
Stabilization and consolidation of 21,000 tons of ash piles and super sacks
Treatment of 15,500,000 gallons of heavy metal contaminated acid water (<1 pH)
Solidification of 65,000 tons of acid sludge (<1 pH)
Stabilization of 9,500 tons of highly impacted soils
Consolidation and capping of 20,000 yd3 of NORM slag
Consolidation and capping of 80,000 tons of hazardous slag
Excavation and consolidation of 11,000 yd3 of impacted ditch sediments
Demolition of 18 acres of warehouse, laboratory and office buildings and 250-foot tall concrete smoke stack
Lab packing of 1100 chemicals
Cleaning and demolition of 156 tanks
Re-grading and consolidation:
Non-hazardous slag (44,000 yd3)
Non-hazardous non-slag (28,500 yd3)
Pond berms (88,000 yd3)
Clay cap construction (2,750,000 ft2)
Design and installation of engineered geosynthetic cap system including:
Flexible membrane liner (550,000 ft2 )
Geogrid (223,000 ft2)
Geotextile (233,000 ft2)
Geosynthetic composite liner (550,000 ft2)
Closure of 22 acres of ponds including dewatering and capping with a clay cap
Design, construction and closure of a two acre NORM cell
Design and construction of a cap system on a Low Level Radioactive Landfill
Design, construction and closure of a RCRA equivalent cell for on-site waste consolidation
Construction of a 121,000 ft2 soil-bentonite slurry wall

Solidification-Stabilization

Solidification - StabilizationCase Studies

SLUDGE STABILIZATION SWIB/WWTS CLEANOUT PROJECT Norco, Louisiana

SURFACE IMPOUNDMENT CLOSURE Edgemoor, Delaware

TEX TIN SUPERFUND SITE Texas City, Texas

SLUDGE STABILIZATION
SWIB/WWTS CLEANOUT PROJECT
Norco, Louisiana

SURFACE IMPOUNDMENT CLOSURE
Edgemoor, Delaware

TEX TIN SUPERFUND SITE
Texas City, Texas