PUBLIC HEALTH ASSESSMENT
CENEX SUPPLY AND MARKETING, INCORPORATED
(a/k/a WESTERN FARMERS, INCORPORATED)
QUINCY, GRANT COUNTY, WASHINGTON
The Washington State Department of Ecology (Ecology) requested that the Washington State Department of Health (WDOH) evaluate available environmental sampling data and prepare a health assessment for the Cenex Supply and Marketing, Inc. (Cenex) site, located in Quincy, Washington. The site has been used for the storage and distribution of fumigants.
WDOH has reviewed and evaluated the results of environmental samples collected by the U.S. Environmental Protection Agency (EPA), Ecology, and Cenex from the soil, soil gas, air, and groundwater at the Cenex site. In addition, data from the Washington State Cancer Registry were evaluated to determine if there were more cases of cancer among Quincy area residents (i.e., ZIP code 98848) than would be expected. After careful review and evaluation of these data, WDOH concluded the following:
- WDOH evaluated potential past, present, and future exposure to contaminants detected in the soil at the Cenex site. Contaminants were not at levels expected to result in adverse noncancer health effects, and estimated increased cancer risks were low. For the evaluation, workers and residents were assumed to be chronically exposed to elevated levels of some herbicides, pesticides, and metals that were detected in soil at the Cenex site prior to removal and capping with clean gravel. Current soil contaminant levels are much lower, and do not represent a public health hazard.
- EPA's particulate emission model was used to evaluate potential past exposures to contaminants in dust generated at the Cenex site. The estimated health risks from these exposures was low.
- A low level of 1,2-dichloropropane (1,2-DCP) was detected in indoor air in one room at the Quincy high school during a February 1998 investigation. The detection was below a level expected to cause chronic health problems for most people. More comprehensive and sensitive follow-up indoor air sampling conducted inside the high school in August 2000 found no 1,2-DCP or other chemicals at levels of health concern. Additional indoor air sampling was conducted inside Quincy high school in November 2001, the results of which will be evaluated by WDOH in a separate health consultation.
- Past exposure of students and staff at the junior high school to overspray from the former Cenex rinsate pond spray system represents an indeterminate public health hazard. No air sampling of the overspray mist was conducted during its brief operation, so measurement of staff and student exposures is not possible. However, based on the concentrations and the limited number of chemicals detected in a rinsate pond sample, and the limited timeframe in which the exposures would have occurred, a long-term health risk is not expected.
- Contaminated groundwater from the Cenex site does not represent a public health hazard, as it is not being used for domestic (i.e., drinking and cooking) purposes.
- Based on WDOH's analysis of the 24 major types of cancer, using all 7 years of available data (1992-1998), overall, there were fewer total reported cases of cancer in Quincy during this time period than would be expected in a community in Washington of the same size and age structure. A more detailed discussion of this analysis is presented in the Health Outcome Data Evaluation section of this health assessment.
This public health assessment was prepared at the request of the Washington State Department of Ecology (Ecology) to evaluate potential exposures of workers and residents living near the Cenex Supply and Marketing, Inc. (Cenex) facility to hazardous substances released into the environment. Cenex and previous owners/operators at this location have a history of controlled and uncontrolled releases of fumigants and other pesticides to the environment that might have resulted in exposures of workers and residents. This assessment evaluates the potential past, present, and future health threats.
The Cenex site is located in the city of Quincy, Grant County, Washington, south of the Burlington Northern railroad tracks, on the north side of Division Street, between Fourth Avenue S.E. and Sixth Avenue S.E. (Figure 4). Quincy (population 3,715) is located in the east-central part of the state, in the northwest portion of the Columbia Basin Irrigation Project, at the southern base of the Beezley Hills (Figures 2 and 3). Cenex employs approximately 27 people at the Quincy facility. Adjacent facilities include other agri-chemical and fertilizer businesses, and seed, grain, and fresh-pack potato processing facilities. The nearest residential area is approximately 160 yards southeast of the site.2
Quincy has five municipal supply wells; three online and two standby wells, that draw water from a deep (from 381 to 409 feet below ground surface) basalt aquifer (Figure 8). The closest municipal well (Well # 5) is approximately one-half mile east-southeast of the Cenex site. The nearest known domestic wellis a closed well at the railroad depot, approximately 170 yards from the site. Apublic high school and a junior high school are located 195 yards and 225 yards from the site, respectively.2 Population demographics within a quarter-mile radius of the site are presented in Figure 1, Appendix B.
The site was occupied by a livestock operation in the 1950sthat later closed, and then was vacant until 1974. At that time, a liquid fertilizer and soil fumigant storage and distribution facility was established by Western Farmers Cooperative. A storage area at the site, consisting of multiple tanks, was constructed on a concrete slab and surrounded by an earthen berm. Fumigants stored at the site included DD (dichloropropane, 1,3-dichloropropene), DD with chloropicrin (dichloropropane, 1,3-dichloropropene, and trichloronitromethane), Telone (1,3-dichloropropene and related C3 hydrocarbons), and Telone C-17 (1,3-dichloropropene, trichloronitromethane). Several fertilizers were also stored at the site. The tanks were plumbed to an electric pump within the earthen dike, and from the pump to hoses which were located beyond the dike for loading and unloading trucks, nurse tanks, and application apparatus at street level outside the containment area. Spillage from these hoses onto the soil outside the earthen berm might have occurred on the south side of the containment facility.3, 4
The facility was taken over by Cenex in 1982, and used for storage and distribution of fumigants including Telone, Telone II, Telone C-17, and Metham-Sodium (sodium N-methyldithiocarbamate). Some tanks were used for liquid fertilizer storage until 1985 and included UAN 32-0-0 (urea ammonia nitrate, 32% free ammonia, 0% ammonium nitrate, 0% urea), Aqua Ammonia, and 9-30-00 (9% nitrogen, 30% phosphorous and 0% potassium).3
The extent of pastreleases by Western Farmers Cooperative and Cenex is unknown. In 1986, fumigant hoses were fitted with dry connections to prevent releases into the environment. Once the dry connections were fitted in 1986, the potential for release from the hoses was significantly reduced. No record exists of other herbicides being handled or stored on the site prior to 1986.3, 4
Interviews with Cenex employees suggest that an undocumented fumigant spill occurred shortly before Cenex acquired the site property in 1982.4, 5 Reportedly, approximately 2,000 gallons of Telone were released during that incident. Although the product was contained within the bermed area, it reportedly soaked into the ground under the fumigant storage facility. No known effort was made to recover the product.4
In 1986, Cenex installed a rinsate collection system to contain herbicide, pesticide, and fertilizer rinsate water generated while cleaning and rinsing application equipment and pesticide containers prior to disposal. The collection system consisted of an elevated concrete containment pad which drained to a concrete containment pond. The rinsate pond was located directly west of the fumigant storage facility and had a capacity of approximately 55,000 gallons. No records exist of any disposal activities for tank residual mixtures or rinsate waters prior to the installation of the rinsate collection pad and evaporation pond.3, 4 Release of rinsate water might have occurred at the pond location prior to construction of the containment facility. The method of sealing the joints between the walls and floor of the pond is unknown. The pond was fenced, with a gate on the south side for cleanout.
After application equipment and pesticide containers were washed, contents of the pond were allowed to evaporate. However, because evaporation rates were slower than the fill rates, an aeration system was installed in 1986 to enhance evaporation. The system operated for about 6 months, but was ineffective. It was replaced by a spray system to enhance evaporation. The effectiveness of the spray evaporation system was marginal, and rinsate collection continued until 1988, when use of this facility ceased. In spring 1990, contents of the pond were tested and applied to a 100-acre Cenex-leased agricultural field, located outside of Quincy. Approximately 30,000 gallons of pond sludge were applied.4, 6, 7 Rinse water used to clean the pond was also applied to the Cenex-leased field. The concrete walls were then pushed over and onto the rinsate pond floor, and surface soil surrounding the pond was used to fill it to grade. Operation of the fumigant storage facility ceased in 1991. Shortly thereafter, some of the tanks were moved from the containment area to an area just west of the rinsate pond site pending decontamination and salvaging. The site was fenced in 1996 to prevent access by nonemployees.
In August 1991, the Washington State Department of Ecology inspected the Cenex facility and, in April 1992, issued Cenex an Administrative Order requiring development and implementation of a site assessment plan (SAP) for the area in and around the former rinsate pond.4, 5
The U.S. Environmental Protection Agency conducted a site assessment of the former rinsate pond area on May 10-11, 1993, to determine whether there had been violations of the Resource Conservation and Recovery Act (RCRA) and/or the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA). Results of the site assessment investigation were also used to derive a Hazard Ranking System (HRS) score for possible National Priorities List (NPL) ranking.8 The site assessment included collection of four on-site surface soil samples, one background surface soil sample, and five sludge/soil samples from the excavated rinsate pond and from the perimeter of the pond. Samples were analyzed by standard EPA methods for the 45 herbicides present or previously used at the site, and for 63 volatile organic compounds (VOCs). One sample was also submitted for target analyte list (TAL) metals. Sample results are presented in Appendix A. Based on the soil and sludge sampling results, EPA determined that no further involvement was necessary. Since 1993, EPA has not been involved at the Cenex site.
On May 19, 1993, Ecology requested that Cenex properly dispose of the fumigant tanks and the sludge contained within the tanks. From August 1994 to February 1995, Cenex contractors, with Ecology oversight, decontaminated and removed all tanks of the former fumigant storage facility. A revised SAP that included the fumigant storage facility area and adjacent soil was completed on April 7, 1995.9 On June 6, 1995, soil sampling was conducted at the site to address requirements of the SAP. Sampling locations included the rinsate pond, comprising soil above and below the concrete floor, the rinsate pond concrete floor and walls, concrete and soils within the fumigant storage facility containment area, soils surrounding the rinsate pond, and fumigant storage facility. A total of 85 soil samples were collected. Samples were analyzed for site-related herbicides, fumigants, and metals.3, 5 The results are presented in Appendix A.
A total of 360 tons (277 cubic yards) of soil and concrete removed from the rinsate pond was stockpiled onsite, then transported to the Rabanco Landfill (a permitted hazardous waste facility) in Roosevelt, Washington, on May 1 and 2, 1997. The site was then wet down with a water truck, and clean gravel was placed over the site to suppress dust emissions.3, 4, 5 In September 1998, Ecology and Cenex signed an Agreed Order, which required Cenex to install and operate a soil vapor extraction (SVE) system, institute a supplementary site investigation and pilot study, and perform groundwater monitoring to evaluate both the effectiveness of the air sparging technology and gather information on the nature and extent of chemicals in the groundwater. Between August and December 1998, all of the interim actions were completed (the installation of five additional monitoring wells, an SVE system, and an air sparging system). In November 1998, the SVE and air sparging systems began operating. These systems are intended to help remove contaminants from the shallow soils and to expedite degradation of contaminants in the groundwater underneath the site. To date, Cenex has installed and sampled 29 on-site and off-site groundwater monitoring wells, collected site and background soil samples, on-site and off-site subsurface soil gas samples, and on-site and off-site air samples. A Feasibility Study was finalized in May 2000 that describes the various cleanup alternatives. In early 2001, Ecology selected the final cleanup action based upon MTCA criteria. Ecology and Cenex Harvest States Cooperative entered into a Consent Decree to implement the clean-up action.
WDOH has conducted numerous site visits, has attended numerous public meetings, and has mailed periodic community update notices since becoming involved in 1997. WDOH has met with concerned residents, Quincy officials, Cenex environmental consultants, and agency representatives to share and discuss information relevant to the site. In 1998, update letters were mailed to area residents summarizing the preliminary findings of the health assessment. At a public meeting in Quincy in August 1998, WDOH summarized the preliminary results of the health assessment. A press release announcing the availability of the draft health assessment, and copies of the draft health assessment were distributed for public review and comment in spring 2000. WDOH was available to address health-related questions at a Quincy concern-sponsored public meeting in April 2000. A more detailed list of activities conducted by WDOH and other agencies is located in the public health action plan section at the end of this report.