Infrastructure Alternatives conducted a successful feasibility trial which lead into full-scale remediation of creosote-contaminated industrial waste ponds. A wood-treating facility had previously been located on the project site; each of two ponds contained a layer of thick, black oily sludge. The sludge was contaminated with creosote, various polyaromatic hydrocarbons (PAHs) and metals.
To remediate the ponds, the sludge was removed with utilization of a suspended pump and dewatered in geotextile tubes. Infrastructure Alternatives and its subcontractors constructed a dewatering pad by leveling a large area, building berms around it and lining it with high-density polyethylene (HDPE) to prevent groundwater contamination.
A centrifugal pump was used to pull the loose sludge from the ponds and deliver it to geotextile tubes which had been placed around the circumference of the dewatering pad. The remaining portion of the sludge from the ponds was removed mechanically and placed in the center of the dewatering pad to air dry. Filtrate from the geotextile tubes and separated water from the mechanically-excavated sludge was collected and treated in temporary (mobile) water treatment units before being discharged back into the ponds.
Due to the contamination in the pond sediment, all operations were covered under OSHA standard 1910.120 (the Hazardous Waste Operations and Response or HAZWOPER standard).