- Two incineration systems: the Hybrid Thermal Treatment System® HTTS-2 and HTTS-3; HTTS-2 designed to process solids, sludges, tars, aqueous wastes, and organic liquids; and HTTS-3 designed to process aqueous wastes and organic liquids
- Solids transferred to feed preparation building where materials were mixed and screened
- The HTTS-2 consisted of two chambers (the kiln and SCC) and a gas cleaning system consisting of a quench system, gas conditioner, wet scrubber system, and a vane separator; the HTTS-3 consisted of a combustion chamber and a gas cleaning system
- Solids, sludges, and aqueous wastes fed to the HTTS-2 kiln by a screw conveyor; organic liquid wastes used as primary fuels in the kiln
- Residual ash from kiln collected, landfilled, and capped on site
CERCLA and State: Texas
- ROD signed 3/15/85
- RP-lead; EPA oversight
2865 (Industrial organic chemicals)
|Point of Contact:|
Texas Natural Resources Conservation Commission
Styrene tars, VOCs, PCBs, and metals:
benzene, vinyl chloride, 1,1,2-trichloroethane, lead, cadmium, mercury, and chromium
On site pits - styrene tars and chemical wastes - wood preserving wastes
Type/Quantity of Media Treated:
Soil, sludge, organic liquids, and aqueous wastes
- 10,471 tons aqueous wastes
- 7,568 tons organic liquids
- 283 tons sludges and tars
- 4,699 tons soil
Purpose/Significance of Application:
Mechanical problems were encountered, caused in part by lack of accurate waste characterization; onsite incineration halted in December 1991 because of dispute between the contractor and RP; remedy changed to off-site incineration in part because of dispute and mechanical problems
Regulatory Requirements/Cleanup Goals:
Destruction and Removal Efficiency (DRE) of 99.99% for each principal organic hazardous constituent as required by Resource Conservation and Recovery Act (RCRA) incinerator regulations in 40 CFR part 264, subpart O; 99.9999% DRE for PCBs as required by Toxic Substances Control Act (TSCA) regulations in 40 CFR part 761
Emissions and performance data indicate that all DRE and emissions standards have been met
The MOTCO site was established in 1959 for the recycling of styrene tars. From 1961 to 1968, on-site pits that held styrene tars were used for the disposal of chemical wastes from local industries. In March 1985, a Record of Decision (ROD) that required source control was signed, and in September 1989, a ROD that addressed off-site migration of contaminants was signed.
The remedy selected for the first Operable Unit (OU-1) was off-site treatment and disposal of contaminated material; however, the ROD specified that on-site incineration was a viable alternative to be evaluated during the design phase. A later Consent Decree required on-site incineration and established incinerator requirements.
The site operated two incineration systems. The first system was called the Hybrid Thermal Treatment System® 2 (HTTS®-2), and the second system was referred to as HTTS-3. The HTTS-2 consisted of a rotary kiln, a secondary combustion chamber (SCC), and a gas cleaning system. This incineration system processed solids, sludges, tars, aqueous wastes, and organic liquids. The HTTS-3 consisted of a combustion chamber and gas cleaning system identical to the SCC and gas cleaning system of the HTTS-2. The HTTS-3 processed only aqueous wastes and organic liquids.
In December 1991, the HTTS-3 had passed the trial burn and was performing under interim operating conditions, and the HTTS-2 was in the process of conducting a trial burn when the contractors stopped incineration and filed a lawsuit against the responsible party (RP) for breach of contract. Due to the dispute and several technical problems (including slagging), on-site incineration did not resume.
In January 1993, an Explanation of Significant Differences (ESD) specified off-site incineration of the remaining sludges, tars and organic liquid. The remaining soil was to be capped on site.
The cost incurred during the on-site incineration was approximately $76 million consisting of $20 million in capital costs and $56 million in operating costs.