Incineration at the MOTCO Superfund Site, Texas City, Texas

Site Name:

MOTCO Superfund Site

Location:

Texas City, Texas

Period of
Operation:

May 1990 to December 1991

Cleanup
Type:

Remedial Action

Vendor:

IT Corporation
312 Directors Drive
Knoxville, TN 37923
(423) 690-3211

Technology:
- 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

Cleanup Authority:
CERCLA and State: Texas
- ROD signed 3/15/85
- RP-lead; EPA oversight

SIC Code:
2865 (Industrial organic chemicals)
Point of Contact:
Ashby McMullan
Texas Natural Resources Conservation Commission
(512) 239-1000

Contaminants:
Styrene tars, VOCs, PCBs, and metals:
benzene, vinyl chloride, 1,1,2-trichloroethane, lead, cadmium, mercury, and chromium

Waste Source:
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

Results:
Emissions and performance data indicate that all DRE and emissions standards have been met

Description:
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.