K-1435 Wastewater Treatment System for the Toxic Substances Control Act Incinerator Wastewater at the East Tennessee Technology Park, Oak Ridge, TN

This paper discusses the design and performance of a wastewater treatment system installed to support the operation of a hazardous waste incinerator. The Oak Ridge Toxic Substances Control Act Incinerator (TSCAI), located at the East Tennessee Technology Park (ETTP), is designed and permitted to treat Resource ConservatioN and Recovery Act (RCRA) wastes including characteristic and listed wastes and polychlorinated biphenyl (PCB)-contaminated mixed waste. the incinerator process generates acidic gases and particulates which consist of salts, metals, and radionuclides. These off-gases from the incinerator are treated with a wet off-gas scrubber system. The recirculated water is continuously purged (below down), resulting in a wastewater to be treated. Additional water sources are also collected on the site for treatment, including storm water that infiltrates into diked areas and fire water from the incinerator's suppression system. To meet regulatory requirements for discharge, a wastewater treatment system (WWTS) was designed, constructed, and operated to treat these water sources. The WWTS was designed to provide for periodic fluctuation of contaminant concentrations due to various feed streams to the incinverator. Blow down consists of total suspended solids (TSS) and total dissolved solids (TDS), encompassing metals, radionuclide contamination and trace organics. The system design flow rate range is 35 to 75 gallons per minute (gpm). The system is designed with redundancy to minimize time off-line and to reduce impacts to the TSCAI operations. A novel treatment system uses several unit operations, including chemical feed systems, two-stage chemical reaction treatment, microfiltration, sludge storage and dewatering, neutralization, granular activated carbon, effluent neutralization, and a complete programmable logic controller (PLC) and human-machine interface (HMI) control system. To meet the space requirements and to provide portability of the WWTS to other applications, the system was installed in three, over-the-road semi trailers, and interconnected with piping and power. Trailers were oriented on a small site footprint to facilitate ease of installation. A remote sump pump skid was provided to convey water from two holding sumps adjacent to the treatment process. An accumulation tank and pump were also provided to receive miscellaneous wastewaters for treatment if they meet the waste acceptance criteria. The paper includes details of the technology used in the design, the requirements for compliance, and the initial performance demonstration and jar testing results. The WWTS successfully allowed for highly efficient, high-volume treatment with compliant discharge to off-site surface water