On-Site Incineration at the FMC Corporation - Yakima Pit Superfund Site Yakima, Washington 79 ------- Incineration at the FMC Corporation - Yakima Pit Superfund Site Yakima, Washington Site Name: FMC Corporation - Yakima Pit Superfund Site Contaminants: • DDD, DDE, DDT, dieldrin, endosulfan, ethion, malathion, parathion, cadmium, chromium, and zinc. • DDD concentrations of 76 mg/kg, DDE concentration of 210 mg/kg, and DDT concentrations of 210 mg/kg • The maximum concentrations of contaminants (mg/kg) detected in soil were DDD (76), DDE (28), DDT (210), dieldrin (40), endosulfan (7,000), ethion (180), malathion (170,000), parathion (3,300), cadmium (6), chromium (320), and zinc (1,020). Period of Operation: January 1993 - May 1993 Location: Yakima, Washington Cleanup Type: Remedial action Vendor: VESTA Technology Ltd. 1670 West McNab Road Ft. Lauderdale, FL 33309 Technology: On Site Incineration • Solids crushed and mixed with soil • Incineration system consisting of co-concurrent rotary kiln and secondary combustion chamber (SCC) • Enclosed twin screw conveyor transported soil and debris to the unit • Soil had a through part rate of 60 kg/min with kiln temperature of 650 °C, the SCC temperature of 1,107 °C. • Ash discharged onto conveyers,sampled and analyzed, and then landfilled. Cleanup Authority: CERCLA • ROD Date: 9/14/90 • EPA-lead SIC Code: 2879 (Pesticides and Agricultural Chemicals) Point of Contact: Lee Marshall U.S. EPA Region 10 1200 Sixth Avenue Seattle, Washington 98101 (206) 553-2723 80 ------- Incineration at the FMC Corporation - Yakima Pit Superfund Site Yakima, Washington (Continued) Waste Source: Type/Quantity of Media Treated: Pesticide production wastes Soil and Debris disposed of in an unlined pit • 5,600 cubic yards Purpose/Significance of Application: Initially, was estimated in the ROD that between 900 and 4,000 cubic yards of material were contaminated. However, contamination extended deeper than previously anticipated and, as a result, over 5,600 cubic yards of material was excavated for incineration. Regulatory Requirements/Cleanup Goals: • Destruction and Removal Efficiency (DRE) of 99.99 for all constituents of concern as required by Resource Conservation and Recovery Act (RCRA), 40 CFR Part 264 Subpart O. Results: • Monitoring and trial burn data indicate that all DRE and emission standards have been met. « Analytical data of residuals indicate that cleanup goals have been met Cost Factors: « The actual cost for remediation using the incineration system was approximately $6,000,000. Description: Between 1952 and 1969, wastes contaminated with pesticides were disposed of on the site in an unlined waste disposal pit. It was estimated that 2,000 pounds of material was disposed of on the site in the pit contaminating soil with 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), 1,1-dichloro-2,2-bis(p- chlorophenyl)ethylene (DDE), 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT), and dieldrin. A Record of Decision (ROD) signed in September 1990 specified on-site incineration as the remedial technology. Site cleanup goals and destruction and removal efficiency (DRE) standards were established for constituents of concern. On-site incineration began in January 1993 and was completed in May 1993. The treatment system consisted of a rotary kiln and an SCC. Enclosed twin screws moved the soil to the kiln for treatment. Ash was collected and flue gas was completely incinerated. Incineration has achieved the soil cleanup goals specified in the ROD. The actual cost for remediation using the incineration system was approximately $6,000,000. 81 ------- FMC Corporation - Yakima Pit Superfund Site Executive Summary This report presents cost and performance data for the application of on-site incineration at the FMC Corporation - Yakima Pit (Yakima) Superfund site in Yakima, Washington. A rotary kiln incinerator was operated from January 1993 through May 1993 as part of a remedial action. Contaminants of concern at the site included pesticides and metals. The Yakima site was the location of a former pesticide manufacturing plant which operated from 1951 until its closure in 1986. Between 1952 and 1969, wastes contaminated with pesticides were disposed of on the site in an unlined waste disposal pit. It was estimated that 2,000 pounds of material was disposed of on the site in the pit. Soil at Yakima was contaminated with 1,1-dichloro-2,2-bis(p-chlorophenyl)ethane (DDD), 1,1-dichloro-2,2-bis(p- chlorophenyl)ethylene (DDE), 1,1,1 -trichloro-2,2- bis(p-chlorophenyl)ethane (DDT), dieldrin, endosulfan, ethion, malathion, parathion, cadmium, chromium, and zinc. During the remedial investigation, the maximum concentrations of these contaminants in mg/kg detected in the soil were DDD (76), DDE (28), DDT (210), dieldrin (40), endosulfan (7,000), ethion (180), malathion (170,000), parathion (3,300), cadmium (6), chromium (320), and zinc (1,020). A Record of Decision (ROD) signed in September 1990 established a Destruction and Removal Efficiency (DRE) of 99.99% for constituents of concern. In 1991, a Consent Decree was entered in the Eastern District of Washington in which the Responsible Party (RP) for the site agreed to implement the remedial action proposed in the ROD. The RP conducted remedial activities including the operation of a rotary kiln incinerator to dispose of the contaminated soil. The incineration system at Yakima was comprised of a solid waste feed system; a co-current rotary kiln; a secondary combustion chamber (SCC); and an air pollution control system (APCS). The incineration equipment was located on six flat bed trailers and several skids. Contaminated material was fed to the incinerator by a jacketed, twin-screw conveyor. The incinerator volatilized and partially destroyed organic compounds from the contaminated material. Resulting ash from the incinerator was removed by a submerged drag conveyor while the off-gas was drawn into the SCC. The SCC was a down-fired steel shell that provided further combustion of contaminants in the gas. Off-gas from the SCC was then drawn into the APCS, which was divided into three stages. The first stage, which consisted of a quench tank and two Venturis, trapped and collected particulate matter. The second stage, which consisted of a packed bed adsorber and cooling tower, removed acid gases. The third stage, which consisted of an ionized wet scrubber, provided further removal of particulate matter. Ash collected from the incinerator and APCS was sampled and analyzed to determine if it was in compliance with site-specific land disposal requirements, at which time it was either re- incinerated or landfilled on the site. During the five months of operation, the incinerator processed approximately 5,600 cubic yards of contaminated material. Treatment performance and emissions data collected during this application indicated that all performance standards and emissions requirements were achieved. The actual cost for remediation using the incineration system was approximately $6,000,000. U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Solid Waste and Emergency Response Technology Innovation Office 82 ------- FMC Corporation - Yakima Pit Superfund Site Site Information Identifying Information FMC Corporation - Yakima Pit Superfund Site Yakima, Washington CERCLIS #: WAD000643577 ROD Date: September 14, 1990 Treatment Application Type of Action: Remedial (on-site rotary kiln incineration) Period of operation: January 1993 - May 1993 Quantity of material treated during application: 5,600 cubic yards of soil and debris Background Historical Activity that Generated Contamination at the Site: Manufacture of pesticides Corresponding SIC Code: 2879 (Pesticides and Agricultural Chemicals Waste Management Practice That Contributed to Contamination: Waste disposal in an unlined pit Site History: The site operated from 1951 until its closure in 1986. The site has remained vacant since its closure. From 1952 until 1969 wastes containing pesticides were disposed of in an on-site, unlined waste pit and covered with soil. The waste material included raw material containers, soil contaminated by leaks or spills from process equipment, broken bags, and off-specification materials [1], In the 1970s, liquid products were formulated on-site using solvents, emulsifiers, and stabilizers. Spills and leaks of these materials were believed to have been a source of concrete and soil contamination [1]- Contamination at the site was found within a 58,000-square-foot area on the northeastern portion of the 10-acre site. Soil at Yakima was contaminated with pesticides and metals including DDD, DDE, DDT, dieldrin, endosulfan, ethion, malathion, parathion, cadmium, chromium, and zinc. A remedial investigation conducted in 1988 showed elevated concentrations of DDT and other pesticide constituents in the former disposal pit. Removal actions in 1988 and 1989 included excavation, removal, and disposal of 850 tons of contaminated soil from the waste pit [1], A ROD signed in 1990 addressed the contamination that remained in and around the waste pit. The ROD called for on-site incineration of contaminated soil and debris. U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Solid Waste and Emergency Response Technology Innovation Office 83 ------- FMC Corporation - Yakima Pit Superfund Site Site Information (Cont.) Background (Cont.l In April 1992, site mobilization began. By December 1992, incinerator shakedown had begun using contaminated soil. The trial burn scheduled for December 1992 was canceled due to delays in completing incinerator instrumentation installation and checkout. The trial burn was re-scheduled for January 1993. In January 1993, the re-scheduled trial burn was canceled due to mechanical difficulties with the incinerator. After extensive incinerator modifications, the shakedown period was extended. Later in the month an EPA-mandated 72-hour demonstration test of the incinerator using clean soil was completed. Incineration of contaminated soil resumed under operational guidelines and limits established in an extended shakedown plan. In March 1993, the extended shakedown activities were completed. The trial burn was conducted and successfully completed later in the month. Between January 1993 and May 1993, approximately 5,600 cubic yards of contaminated material were incinerated. This amount included the material which was incinerated during the shakedown period. Incinerator ash was disposed of on the site. Backfilling of the ash was completed in June 1993. Site demobilization activities were completed in July 1993. Regulatory Context: In 1983 the Yakima site was placed on the National Priorities List (NPL). The selected remedy was implemented under the provisions of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), as amended by the Superfund Amendments and Reauthorization Act of 1986 (SARA), and the National Contingency Plan (NCP) in 40 CFR part 300 [6]. The DREs were set in accordance with Resource Conservation and Recovery Act (RCRA) incinerator regulations in 40 CFR part 264, subpart O. Remedy Selection: On-site incineration was selected as the remedy for contaminated soil and debris at the Yakima Pit Superfund site based on treatability study results, its ability to be protective of human health and the environment, and its ability to comply with Applicable or Relevant and Appropriate Requirements (ARARs). U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Solid Waste and Emergency Response Technology Innovation Office 84 ------- FMC Corporation - Yakima Pit Superfund Site Site Information (Cont.) Timeline Table 1. Timeline [ 1, 2] Date Activity 1951 - 1986 Pesticides were manufactured at the Yakima site 1952- 1969 Wastes from pesticide manufacturing were disposed of in an on-site unlined pit 1983 Yakima site placed on NPL 1988 Remedial Investigation 1988 First Removal Action 1989 Second Removal Action September 1990 ROD signed specifying on-site incineration April 1992 Site mobilization begins January 1993 72-hour demonstration test completed March 1993 Incineration Performance Test completed May 1993 Incineration completed June 1993 On-site backfilling of ash completed July 1993 Site was demobilized August 1993 Remedial Completion Inspection of the site Site Loaistics/Contacts Site Management: RP-lead Oversight: EPA Remedial Project Manager: Lee Marshall U.S. EPA Region 10 1200 Sixth Avenue Seattle, WA 98101 (206) 553-2723 Treatment System Vendor: VESTA Technology Ltd. 1670 West McNab Road Ft. Lauderdale, FL 33309 U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Solid Waste and Emergency Response Technology Innovation Office 85 ------- FMC Corporation - Yakima Pit Superfund Site Matrix Identification Type of Matrix Processed Through the Treatment System: Soil and debris from an unlined waste disposal pit Contaminated concrete from the manufacturing plant Contaminant Characterization Primary Contaminant Groups: Pesticides and • The maximum concentrations of Metals contaminants (mg/kg) detected in soil The contaminants of greatest concern were: DDD, DDE, DDT, dieldrin, endosulfan, ethion, malathion, parathion, cadmium, chromium, and zinc. were DDD (76), DDE (28), DDT (210), dieldrin (40), endosulfan (7,000), ethion (180), malathion (170,000), parathion (3,300), cadmium (6), chromium (320), and zinc (1,020). Matrix Characteristics Affecting Treatment Costs or Performance Information on matrix characteristics, such as soil classification, moisture content, and density, was not available. Primary Treatment Technology Supplemental Treatment Technology VESTA Technology, Ltd. Model 200 Transportable Hazardous Waste Incinerator (incineration system) including: Pretreatment (solids): Crushing Mixing Solid waste feed system Co-current, rotary kiln Secondary combustion chamber Post-Treatment (air): Quench tank Venturi scrubber Cooling tower Packed bed absorber Ionized wet scrubber Post-Treatment (water): Surge tank Particulate filters Carbon filter U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Solid Waste and Emergency Response Technology Innovation Office 86 ------- FMC Corporation - Yakima Pit Superfund Site Treatment System Description (Cont.) System Description and Operation In addition to the soil, approximately 10 cubic yards of concrete and a limited amount of decontamination fluid was incinerated. The concrete was crushed to 1 inch pieces and mixed with the soil for incineration. Decontamination fluid, generated from cleaning concrete and personal protective equipment was collected and also mixed with soil for incineration. The main components of the incineration system included the rotary kiln, the SCC, and the APCS. The equipment was located on flat bed trailers and skids. The final system consisted of six trailers in a 100-foot by 120- foot work area [3]. The waste feed system consisted of a variable speed J.C. Steele Feeder, a weigh belt conveyor, an inclined drag conveyor and a twin 6-inch screw feeder. The J.C. Steele Model 88C Even Clay Feeder was a multi- shafted conveyor which included a hopper and hopper extension to hold soil fed to it by a mechanical loader. The rate of discharge from the feeder was controlled by adjusting the rate at which the screws turned [3]. Solids from the Steele feeder fell onto a Model MD-24T Thayer weigh belt conveyor. The belt passed over an isolated frame connected to a load cell, which measured the deflection caused by the weight of the soil. It then transmitted a signal to a controller which governed the rate at which the Steele feeder discharge soil to the feed system [3]. Solids fell from the weigh belt to a bottom carry drag conveyor manufactured by Taunton Engineering. The drag conveyor was 25 feet long and had a 12 foot high discharge flange. The conveyor was driven by a 2 horsepower (hp) motor [3]. Soils fell from the drag conveyor onto a water-jacketed twin screw conveyor, which fed the soils into the kiln. The conveyor was driven by a 6.7-hp drive motor. Water was circulated in the jacket to protect the conveyor components from the high temperatures generated by the kiln. The co-current kiln was 25 feet in length, had an inside diameter of 5.9 feet, and was lined with high-temperature refractory. The kiln was designed to operate with excess air or oxygen and to handle a maximum throughput rate of 10,000 pounds per hour. The average throughput of waste feed was 60.6 kg/min. The kiln was rated at 10.5 million BTU/hr and operated at 650°C. Residual ash from the kiln fell from the discharge end of the conveyor into the ash drag conveyor. The bottom end of the conveyor was completely submerged in water to cool the hot ash. The conveyor discharged the ash into a hopper. The ash was then sampled and analyzed to determine if it met requirements for on-site land disposal. The TCLP analyses of the ash confirmed that it was not a RCRA characteristic waste, and therefore could be landfilled on site. Flue gas from the kiln was routed to the SCC to ensure complete combustion of volatilized contaminants. The SCC operated at approximately 1,107°C and was equipped with an excess air burner. Air flow in the SCC was co-current to the flue gas flow. The burner was rated at 12.5 million BTU/hr. The SCC was 30 feet long and had an inside diameter of 6.5 feet. U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Solid Waste and Emergency Response Technology Innovation Office 87 ------- FMC Corporation - Yakima Pit Superfund Site Treatment System Description (Cont.) The exhaust gas from the SCC was then routed to the system's APCS. TheAPCS contained three distinct units. The first stage consisted of a quench tank and a venturi scrubber to reduce flue gas temperature and remove particulates. Acid gas was neutralized by a pH-controlled spray in the venturi. Solids were removed from the process water by a clarifier. The clarifier used a filter press to remove solids, and the treated water was recycled to the venturi. The second stage of the APCS consisted of a packed bed absorber and a cooling tower to subcool the off-gas. The process water for the absorber was pH controlled to ensure sufficient removal efficiency of acid gas. The subcooling of the off-gas was in a closed loop through a heat exchanger to reduce heavy metal emissions. Blowdown from the second stage was treated and then used as makeup water for the first stage [3]. The third step consisted of a two-stage ionized wet scrubber to remove particulates. The scrubber used high voltage ionization to electrostatically charge particulates in the gas stream before they entered the scrubber section. Particles greater than 3 microns were collected by inertial impaction. Smaller particles were attracted to the neutral surfaces of the scrubber due to the electrostatic charge which had been imparted on them. Blowdown from the scrubber was treated and then used as makeup water for the first stage [3]. The blowdown from the second and third stages was treated in a system which consisted of a 1,000 gallon surge tank, a three-stage particulate filter, an activated carbon filter, and a particulate post filter. The surge tank acted as a primary settling tank for particulate removal and provided capacity to handle excess flow conditions. The three-stage particulate filter was designed to remove particulates larger than 1 micron. The carbon filter was designed to remove organic compounds that were present. The post filter removed any particulate larger than 0.5 microns. The solids collected by the filters were collected and sampled prior to disposal [3]. Combustion gases were drawn through the kiln system and APCS by an induced draft fan and were exhausted through a 30-foot fiberglass reinforced plastic stack. Typical flue gas velocity was 85 m3/min. Parameter Value Residence Time NA System Throughput 60.6 kg/min Kiln Temperature 650°C Operating Parameters Affecting Treatment Cost or Performance Table 2. Summary of Operating Parameters U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Solid Waste and Emergency Response Technology Innovation Office 88 ------- FMC Corporation - Yakima Pit Superfund Site Treatment System Performance Cleanup Goals/Standards The cleanup goals and standards were specified in the ROD. The DRE standards were set based on RCRA incinerator regulations in 40 CFR part 264, subpart O. A DRE of 99.99% was required for each constituent of concern. Ash residuals were tested using the Toxicity Characteristic Leaching Procedure (TCLP) prior to on-site disposal. Cleanup standards in mg/kg were set for the following constituents in soil: DDD (5.1), DDE (3.6), DDT (3.6), Dieldrin (0.076), cadmium (8.0), hexavalent chromium (1.0), endosulfan (4.2), ethion (42.4), malathion (1,695), parathion (11.0), zinc (500). Cleanup standards in mg/100 cm2 were set for the following constituents in concrete and other surfaces: DDD (0.0065), DDE (0.0046), DDT (0.0046), dieldrin (0.0001), endosulfan (0.010), ethion (0.270), malathion (8.2), and parathion (2.4). The soil cleanup criteria were established according to a risk assessment which allowed a 5 x 10~6 excess lifetime cancer occurrence. A cumulative hazard index was set at less than or equal to 1 for all noncarcinogenic substances. Treatment Performance and Compliance A trial burn conducted at Yakima was designed to operate the incineration system at conditions that would reflect worst-case destruction and removal of all constituents of concern. Hexachlorobenzene was selected as the POHC. The reported DRE for this POHC is included in Table 3. The incinerator at Yakima operated within the operating limits established during the trial burn, signifying that all cleanup requirements established in the ROD were met. The AWFCOs limits used during the operation of the incinerator are shown in Table 4. Information about the frequency of AWFCOs was not available. Available trial burn and typical operating parameters are shown in Table 5. The residual ash was sampled and analyzed using the Toxicity Characteristic Leaching Procedure (TCLP) to determine if it was in compliance with on- site disposal requirements. These data are presented in Table 6. Table 3. Average Destruction and Removal Efficiencies from Trial Burn [4] Contaminant Average Contaminant Feed Rate in Soil (Ib/hr) Average Contaminant Rate in Stack Gas Emissions (Ib/hr) Average Contaminant Concentration in Residual (Mq'kq) DRE(%) Hexachlorobenzene 3.0 2.46 x 10"7 0.130 99.999992 U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Solid Waste and Emergency Response Technology Innovation Office 89 ------- FMC Corporation - Yakima Pit Superfund Site Treatment System Performance (Cont.) Table 4. Automatic Waste Feed Cutoffs Parameter Cutoff Limit Maximum contaminated soil feed rate1 67 kg/min Maximum kiln temperature 1,000°C Minimum kiln temperature 600 °C Minimum SCC outlet temperature 1,093°C Maximum quench outlet temperature 100°C Minimum recycle to venturi 150 Lpm Minimum venturi differential pressure 750 mm w.c. Minimum absorber recycle flow 1,000 Lpm Minimum absorber flow water pH 6 Maximum cooling tower inlet temperature 80°C Minimum ionized wet scrubber #1 recycle water flow 1,000 Lpm Minimum ionized wet scrubber #2 recycle water flow 1,000 Lpm Minimum ionized wet scrubber #1 voltage 12 kV Minimum ionized wet scrubber #2 voltage 12 kV Maximum exhaust stack CO concentration 500 ppm Maximum exhaust stack average CO concentration1 100 ppm Maximum exhaust stack 02 4% Maximum exhaust stack flow 175 m3/min Minimum kiln 02 level 6% Minimum SCC outlet 02 level 3% Maximum kiln pressure -1.3 mm w.c. Bypass stack not closed Open 1One hour rolling average U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Solid Waste and Emergency Response Technology Innovation Office 90 ------- FMC Corporation - Yakima Pit Superfund Site Treatment System Performance (Cont.) Table 5. Operating Parameters [4, 7] Parameter Actual Value1 Trial Burn Value Contaminated Soil Feed Rate 60.6 kg/min 81.8 kg/min Fuel Fired Feed Rate 10.5 million BTU/hr 10.5 million BTU/hr Emission Rate Particulate NA 0.0014 gr/dscf HCI NA 0.004 kg/hr Cl2 NA <0.001 kg/hr S02 NA 6.18 ppm NOx (@ 7% 02) NA 1,123.83 ppm Operating Conditions CO concentration in gas 10 ppm 18.44 ppm Exhaust stack 02 concentration 10% 12.97% Kiln temperature 650 °C NA SCC outlet temperature 1,107°C NA Stack gas flow rate 85 m3/min NA Quench outlet temperature 85°C NA 'Anticipated values as reported in the Incineration Work Plan. Table 6. TCLP Comparison for Residual Regulatory Threshold Constituent Concentration (mq/L)" Averaqe TCLP Concentration (mq/L)1, Metals Arsenic 5 0.016 Barium 100 0.19 Cadmium 1 0.0028 Chromium 5 0.011 Lead 5 0.020 Mercury 0.2 0.00012 Selenium 1 0.0099 Silver 5 0.0046 Organochlorine Pesticides Chlordane 0.03 0.00037 Endrin 0.02 0.000082 Heptachlor (and epoxide) 0.008 0.00018 Lindane 0.4 0.000037 Methoxychlor 10 0.00011 Toxaphene 0.5 0.0012 Note: Only pollutants that were detected are included in this table. "Excerpted from 40 CFR § 261.24 Table 1. bGeometric mean value of reported ash samples. U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Solid Waste and Emergency Response Technology Innovation Office 91 ------- FMC Corporation - Yakima Pit Superfund Site Treatment System Performance (Cont.) Performance Data Completeness Data are available for concentrations of contaminants in the soil before treatment. Data are also available for concentrations of contaminants in the incinerator residue. These data were periodically collected prior to on-site land disposal. Performance Data Quality According to site personnel, the QA/QC program used throughout the remedial action met the EPA and the State of Washington requirements. All monitoring was performed using EPA-approved methods, and the vendor did not note any exceptions to the QA/QC protocols. Treatment System Cost Procurement Process The RP contracted with VESTA Technology Ltd. to provide and operate the incinerator at the site. Cost Data Quality Actual capital and operations and maintenance cost data are available from the treatment vendor for this application. Cost Data The estimated treatment cost of $6,000,000 was reported by Bechtel Environmental, Inc. A total of 7,840 tons of soil were incinerated. This corresponds to a total unit cost of $770 per ton. A detailed breakdown of these costs was not available. U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Solid Waste and Emergency Response Technology Innovation Office 92 ------- FMC Corporation - Yakima Pit Superfund Site Observations and Lessons Learned Observations and Lessons Learned It was estimated in the ROD that between 900 and 4,000 cubic yards of material were contaminated. However, contamination extended deeper than previously anticipated and, as a result, over 5,600 cubic yards of material was excavated for incineration. Samples from 7 feet below ground surface taken during excavation contained contaminant concentrations above the cleanup goals. EPA determined that excavation below 7 feet was technically impracticable, and that the material did not pose an exposure risk because soil at this depth was constantly submerged below water. Additionally, EPA felt that the groundwater was not at risk due to the excavation of material which had already taken place. Groundwater monitoring was scheduled to take place for five years following the completion of the incineration project [5]. Many problems occurred while trying to get the incinerator operational. Shakedown activities were scheduled for the winter months with average temperatures around 25°F. The cold weather caused many delays in setting up the incinerator. Additionally, the incinerator contractor did not anticipate the amount of monitoring that would occur on-site, which caused further delays [6]. Excavation of contaminated soil at the site was complicated by environmental factors. The water table at the site is at its seasonal low of 7 feet below ground surface during the winter months. Excavation of soil with the water table at this level is preferred but harsh winter conditions in Washington introduced other problems. During the warmer summer months, the water table at the site is at its seasonal high of 6 inches to 1 foot below ground surface. While the warmer temperatures make outdoor operations easier, the high water table hampers soil excavation. 1) Superfund Record of Decision. FMC Corporation Yakima Pit, Yakima, Washington, September 14, 1990. 1) Remedial Action Completion Report. Bechtel Environmental, Inc., May 16, 1994. 1) Performance Demonstration Test Plan: Section 2. VESTA Model 200 Incinerator Engineering and Design Specifications. VESTA Technology, November 1992. 1) Final Results of the Trial Burn Demonstration Test of the VESTA technology. Ltd. Model 200 Incinerator at the Former FMC Pesticide Formulating Facility in Yakima. Washington. Environmental and Risk Management, Inc., April 1993. 1) Explanation of Significant Differences - FMC Corporation Yakima. Washington. U.S. EPA Region X, April 1993. 1) Personal Communication, Mr. Kevin Rocklin, May 19, 1997. 1) Incineration Work Plan - Revision 3. Addendum 2. VESTA Technology, Ltd., January 1993. 1) Cleanup Summary for Incinerator Ash and Waste. Beehtel Environmental, Inc., June 1993. U.S. ENVIRONMENTAL PROTECTION AGENCY Office of Solid Waste and Emergency Response Technology Innovation Office 93 ------- |