SFUND RECORDS CTR ; 5211-00001

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SFUND RECORDS CENTER

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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IX

75 Hawthorne Street San Francisco, CA 94105 AR0013

May 5, 1999

ACTION MEMORANDUM

SUBJECT: Request for a Removal Action at the Gila River Indian Commun ;, Maricopa County, Arizona

FROM: Dan Shane, On-Scene Coordinator, Emergency Response Office (SFD ̂

THRU: Terry Bi-ubaker< Emergency Response Office (SFD-6)

TO: Keith Takata, Director, Superfund Programs (SFD-1)

I. PURPOSE

The purpose of this Action Memo is to request and document approval of the proposed CERCLA removal action described herein for the Gila River Indian Community Toxaphene Site (Site) located near the town of Chandler, Maricopa County, Arizona,.

II. SITE CONDITIONS AND BACKGROUND

Site Status: Non-NPL CERCLIS ID: AZSFN0905455 Site ID: FF Category of Removal: Time-Critical Nationally Significant or Precedent Setting: No

A. Site Description

1. Removal Site Evaluation

In the latter part of December 1998, during the excavation of a trench for a masonry wall at the Pima Chandler Power Substation (Substation), workers detected strong chlorine odors and evacuated the area. The Bureau Of Indian Affair's (BIA) San Carlos Irrigation Project (SCIP) was using an easement on Gila River Indian Community (GRIC) land to rebuild SCIP's existing Substation. The Substation serves the Lone Butte Industrial Park. The construction project was being conducted by BIA, and subcontracted to the Department of Energy, Western Area Power Administration (WAPA).

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On December 31, 1998, SCIP contracted with Environmental Management Systems, Inc (EMS) to conduct sampling and analysis in the trench excavation area. The trench was; approximately 50 feet long, 2-4 feet wide and 18 inches deep. It was! located outside and close to the west fence line of the Substation. 1 Six samples were collected in and around the trench. EMS analyzed the samples for chlorinated pesticides. The toxaphene concentrations in four of six samples were 15000, 20000, 22000 and 24000 milligrams per kilogram (mg/kg). The background sample was non-detect for toxaphene. The EPA Region 9 Preliminary Remediation Goal (PRG) for toxaphene is 0.4 mg/kg for residential areas and 2.7 mg/kg for industrial areas. Other chlorinated pesticides detected were dieldrin (0.08 mg/kg) and 4,4-DDE (0.48 mg/kg). ' j

The report from EMS noted the Site may have been a former pesticide aerial applicator operation. Upon notification of the results of the sampling and analysis, WAPA stopped construction work on the rebuild of the Substation.

The GRIC Department of Environmental Quality (GRIC DEQ) initially contacted the Arizona Department of Environmental Quality (ADEQ) and requested assistance to secure the site and assess the hazards. On January 25, 1999, ADEQ met with GRIC DEQ to assess the site. On January 28, 1999, an ADEQ contractor installed a security fence. In written correspondence dated February 8, 1999, ADEQ, on behalf of the GRIC, requested an EPA removal site evaluation.

On March 1, 1999, the EPA On-Scene| Coordinator and START contractor attended a meeting at the GRIC DEQ office in Sacaton. Representatives from BIA, SCIP and EMS were in attendance. At the meeting it was agreed that SCIP would conduct an assessment'inside the Substation and proposed work areas to assess the hazards to workers. SCIP would use the results of the sampling and analysis to ascertain the extent of contamination and the impact on the. current contract to rebuild the Substation. EPA would conduct a removal site evaluation of the suspected pesticide aerial applicator operation, airstrip and suspected disposal area.

On March 2, EPA obtained aerial photographs which confirmed the presence of a crop duster airstrip located in the area of the Substation. The oldest aerial photo of the airstrip was dated 1964. The airstrip may date back to 1958 according to an employee of the City of Chandler Public Works Department. The airstrip was about 2500 feet long and 40 feet wide. Wide aircraft turnaround areas were located at both ends of the runway. A 1981 aerial photo revealed the Substation was built on the western end of the runway. The area of high toxaphene concentrations is located on the south side of the former airstrip near the west end of the runway. Numerous interviews with various sources revealed little information about aerial applicator operations. It appears that the airstrip was used periodically by crop dusters. There were no fixed structures, tanks or other equipment. It was likely that pesticides were transported by truck to the airfield and loaded into the aircraft. At the end of the

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day, the aircraft and/or transport tanks may have been emptied and

rinsed. The pesticide rinsate may have been dumped by the runway near

the west turnaround area. N

On March 22, 1999, EPA received the sampling and analysis results from the EMS soils investigation. EMS collected 57 samples from various depths within the Substation and adjacent work areas. The maximum toxaphene concentration was 12 mg/kg. Additionally, EMS had collected samples from the trench excavation area for organophosphorus pesticide analysis. Methyl parathion, malathion and guthion (methyl azinphos) were detected in the samples at maximum concentrations of 610 mg/kg, 270 mg/kg and 39 mg/kg, respectively. The PRG for soil contaminated with methyl parathion and malathion is 14 mg/kg and 1100 mg/kg in residential areas, 270 mg/kg and 21000 mg/kg in industrial areas, respectively. Currently, there is no PRG for the organophosphorus insecticide guthion.

On March 26, 1999, the GRlC DEQ procured the services of Dust Pro, Inc, a soil stabilization company. Dust Pro applied ammonium lignosulfonate dust sealant to the airstrip areas which would minimize human exposure to dust emissions for several months.

On March 29, 1999, EPA and START conducted sampling and analysis to determine the horizontal and vertical extent of pesticide contamination in soils within the trench excavation area. Additionally, sampling was conducted in the former airstrip area which included the half mile long runway, east and west aircraft turnaround areas at the ends of the runway. A random systematic grid system was developed for each area and samples were collected at various depths within the grids. A total of 226 soil samples, including 10 background samples, from 114 locations were collected and screened using the Enviroguard Toxaphene Immunoassay Test Kits. A total of 57 soil samples were selected for laboratory analysis to confirm organochlorine compound concentrations. A total of 24 soil samples were screened using the InQuest OP (Organophosphate/Carbamate Screen) and three samples were selected for confirmation laboratory analysis.

2. Physical Location

The Site is located on the GRIC reservation and is less than. 1/4 mile from from the City limits of Chandler. The Site is located just south of Kyrene Road and the E. Pecos Road alignment. The Pima-Chandler Substation is located on the west end of the airstrip. The suspected pesticide disposal area is located adjacent to the west fence line of the substation.

A residential housing development is located about 3/10 of a mile to the north. A cattle auction facility is located to the east and a Waste Management, Inc. solid waste transfer station to the west. Twelve trailer homes are located about a 1/4 mile to the southeast. Areas to the south are mostly open desert lands. There is current and proposed construction activity in close proximity to the Site. Commercial facilities are being built in the Lone Butte Industrial

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Park to the west. Water pipelines, irrigation and drainage systems are being built and the San Tan Freeway is proposed to be built to.the north. The unpaved airstrip has been used for years by local residents as a primary roadway to access Kyrene Road, a paved city street.

3. Site Characteristics

The Site is the former location of a pesticide aerial applicator's airstrip. The Site has been divided into discrete sampling areas for the purpose of the assessment. The suspected pesticide disposal area (substation trench area) is approximately 1600 square feet. The runway is approximately 2500 feet by 40 feet or 100000 square feet. The east turn-around area is approximately 10000 square feet and the west turn-around area is 30000 square feet. The total size of the Site is approximately 141600 square feet or 3.25 acres. The following is a summary of the March 29, 1999 EPA soils investigation:

Background Areas:

Laboratory analytical results for toxaphene concentrations in background samples (BG-2 and BG-5) were non-detect at the specified detection limits of 3.0 mg/kg and 0.5 mg/kg, respectively. Background concentrations for 4,4-DDE ranged from 0.009 mg/kg to 0.19 mg/kg. No other chlorinated pesticides were detected.

Substation Trench Area:

Generally, the highest concentrations of organochlorine pesticide contamination was found in this area. Laboratory analytical results revealed toxaphene concentrations ranging from 6.6 mg/kg to 280 mg/kg at 6 inches below ground surface (bgs), non-detect to 58 mg/kg at 18 inches bgs, and 69 mg/kg to 520 mg/kg at 60 inches bgs. The only other chlorinated pesticide detected was 4,4-DDE. The maximum concentration for 4,4-DDE was 0.34 mg/kg. No organophosphate pesticides were detected in samples.

The Airstrip Runway:

Generally, this area had the lowest concentrations of organochlorine pesticide contamination. Laboratory analytical results revealed toxaphene concentrations ranging from 0.002 mg/kg to 2.6 mg/kg at 6 inches bgs, 0.0026 mg/kg to 0.37 mg/kg at 18 inches bgs, and non-detect at 54 inches bgs. Samples were not analyzed for organophosphate pesticide compounds.

The Airstrip West Turn-Around Area:

Most of the sampling results revealed elevated toxaphene concentrations above the PRGs at 6 inches bgs. Laboratory analytical results revealed toxaphene concentrations ranging from 6.1 mg/kg to 390 mg/kg. The concentration of toxaphene in a sample collected at 18 inches bgs was 1.2 mg/kg: The maximum concentrations of other

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J chlorinated pesticides were 15.0 mg/kgjfor 4,4-DDE, 3.2 mg/kg for dieldrin, 1.6 mg/kg for 4,4-DDT and 1.2 mg/kg for 4,4-DDD. No samples were analyzed for organophosphate pesticide compounds.

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The Airstrip East .Turn-Around Area:

The analytical laboratory results revealed several hot-spot areas. The concentration of toxaphene ranging from non-detect to 160 mg/kg at 6 inches bgs and non-detect to 8.7 mg/kg at 18 inches bgs. The maximum concentrations of other chlorinated pesticides detected were 750 mg/kg for 4,4-DDE, 160 mg/kg for alpha-chlordane, 4.0 .mg/kg for 4,4-DDT and 0.089 mg/kg for gamma-chlordane. No samples were analyzed for organophosphate pesticide compounds.

4. NPL Status

This site was not on the NPL.

III. THREATS TO PUBLIC HEALTH AND WELFARE OR THE ENVIRONMENT

A. Threats to Public Health or Welfare or the Environment

Toxaphene and methyl parathion are the hazardous substances of greatest concern due to their concentration and toxicity. Toxaphene is an organochlorine compound. .Toxaphene was a major broad-spectrum insecticide that was primarily used to control pests on cotton and other food crops and ectoparasites on livestock. Toxaphene. can persist in soils for years and, because of its persistence and toxicity, was banned and taken off the market in the United States in 1982. Toxaphene can be highly toxic following inhalation, ingestion and skin contact. Toxaphene is a respiratory depressant and may cause irritation to the eyes, skin and mucous membranes. Symptoms of exposure may include salivation, nausea, vomiting, muscle cramps or spasms, agitation, -CNS depression, tremors, seizures and respiratory failure. Toxaphene can cause reproductive damage and is a teratogen. High or repeated exposures may cause kidney and liver damage.

Methyl parathion is an organophosphate compound. Methyl parathion may be highly toxic following inhalation,' ingestion, and dermal or eye contact. Methyl parathion may damage the developing fetus and-is a mutagen. In generel, symptoms of exposure are due to the anticholinesterase activity of this class of compound. Organophosphate poisoning include nausea, vomiting, abdominal cramps, diarrhea, headache, eye and vision problems, profound weakness, mental confusion, slurring of speach, difficulty in breathing, seizures and respiratory arrest.

Toxaphene, methyl parathion, malathion, guthion, dieldrin, chlordane (alpha and gamma isomers), 4,4-DDT, 4,4-DDE, and 4,4-DDD are hazardous substance as defined in CERCLA Section 101(14). Pursuant to section 300.415(b)(2) of the National Contingency Plan ("NCP") the following factors were assessed in determining threats to public health or.-.welfare or the environment.

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1. Actual or potential exposure to hazardous substances or

pollutants or contaminants by nearby populations or the food chain.

There was evidence of actual exposure to-these hazardous substances. According to SCIP, eight workers reported symptoms of pesticide poisoning after working in the trench excavation area.

The Site continues to pose a significant threat to the public due to the potential for exposure to hazardous substances. The primary exposure pathways are direct contact and/or inhalation of toxic pesticide dusts and vapors. The Site is in very close proximity to several current and planned construction projects where workers could be exposed to hazardous substances. The runway is used as a main access road to city streets. Children have been observed walking or playing in the fields near the substation area. A school bus was observed on the dirt road paralleling the runway.

2. Actual or potential contamination of drinking water supplies.

There were no nearby surface waters that would be impacted by the contamination. Generally, these compounds are not a threat to ground water supplies because they tend to bin'd very tightly to soil.

3. Hazardous substances or pollutants or contaminants in drums, barrels, tanks, or other bulk storage containers that may pose a threat of release.

No surface or buried pesticide containers have been located to date.

4. High levels of hazardous substances or pollutants or contaminants in soils at or near the surface, that may migrate.

Sample results indicated significant pesticide contamination in surface soils.- These pesticide compounds may migrate off-site by rainwater runoff, erosion and mechanical movement(i.e., grading). Sample results indicated that pesticides have migrated into subsurface soils to a depth of at least five feet bgs in the substation trench area. TCLP analysis of soil samples collected from areas that had the highest toxaphene concentrations indicated the soils could be classified as Non-RCRA Hazardous Wastes which can be landfilled at an approved RCRA Subtitle D Land Disposal Facility. The following table lists maximum contaminant concentrations and EPA Region 9 PRGs.

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Contaminant Maximum Concentration Residential PRG Industrial PRG

Toxaphene 24000 mg/kg 0.4 mg/kg 2.7 mg/kg

4,4-DDT 4 . 0 mg/kg 1.7 mg/kg 13 mg/kg

4,4-DDE 750 mg/kg 1. 7 mg/kg 13 mg/kg

4,4-DDD 1.2 mg/kg 2.4 mg/kg 19 . mg/kg

Dieldrin 3.2 mg/kg

00 <N O

o mg/kg 0.19 mg/kg

Chlordane,alpha 160 mg/kg 1. 6 mg/kg 12 mg/kg

Chlordane, gamma 0.089 mg/kg 1. 6 mg/kg 12 mg/kg

Methyl Parathion 610 mg/kg 14 mg/kg 270 mg/kg

Malathion 270 mg/kg 1100 mg/kg 21000 mg/kg

Guthion 39 mg/kg not listed not listed

5. Threat of fire or explosion.

This factor was not applicable.

6. Availability of other appropriate Federal or State response mechanisms to respond to the release.

The total estimated cost for this removal action was greater than could be immediately funded through BIA, ADEQ or the GRIC DEQ. Although these entities cannot provide the funding necessary to mitigate the releases, they have committed resources in conducting the initial assessment, providing security measures, applying a dust sealant to roadways and providing EPA with phone and power services. The GRIC and BIA will continue to provide support to EPA during the removal action. Additionally, the GRIC has approved a site on the reservation that EPA could use to conduct anaerobic bioremediation of toxaphene contaminated soils.

IV. ENFORCEMENT

This section is enforcement confidential and is presented in Attachment A.

V. ENDANGERMENT DETERMINATION

Actual or threatened releases of hazardous substances from this site, if not addressed by implementing the response action selected in this Action Memorandum may present an imminent and substantial endangerment to public health, or welfare, or the environment.

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VI. PROPOSED ACTIONS AND COST

A. Proposed Action

The primary objective of the removal action will be to remove highly toxic organochlorine and organophosphate pesticide compounds in soils to levels that are protective of human health, welfare and the environment. .

In general, one foot of soil will be excavated from the surface within the east and west aircraft turnaround areas. No surface soils need to be removed from the. airstrip runway. Contaminated soils in the substation trench area will be excavated to various depths but not exceeding six feet bgs. An estimated 1700 cubic yards of contaminated soil may excavated, directly loaded onto trucks and transported to an approved off-site land disposal facility.

An alternative to off-site disposal in a landfill is anaerobic bioremediation technology. CERCLA and the NCP explicitly promote the use of alternative technologies to effect permanent cleanups. This alternative would involve the excavation of several treatment pits in a remote area of the reservation, the addition of soil amendments and biologically seeded soil, installation of an HDPE liner cover and. periodic monitoring for up to one year. The GRIC has approved this treatment process and has selected a site on the reservation that could be used by EPA to construct and operate the treatment system.

1. Scope of the Proposed Action. The proposed action will involve the following activities:

• Provide site security during the removal action • Develop and implement a Health & Safety Plan • Develop and implement an air surveillance program • Conduct dust suppression actions to reduce airborne dust

emissions • Excavate and stockpile contaminated soils • Conduct off-site transportation and disposal and/or

anaerobic bioremediation activities on the reservation • Utilize field immunoassay test kits and fixed laboratory

analysis for cleanup confirmation analysis • Perform restoration activities • Coordinate all removal activities, including community

relations, with the GRIC and BIA

2. Long-Term Remedial Action

The proposed removal action should preclude the need for any long-term remedial actions at this Site.

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3. Project Schedule

Removal activities could begin in late May 1999. It is expected that the initial removal activities involving the excavation and stockpiling of soils would be completed in one week. In the case of anerobic bioremediation, the soil screening and treatability study could be completed by July 1, 1999. The construction of the treatment system could begin July 15, 1999. Placement of soils into the treatment units, addition of soil amendments, installation of vents and covering would take about one week. The treatment process could take anywhere from three months to a year to complete. Periodic monitoring including sample collection would be conducted to ensure the treatment was proceeding within established parameters. In the case of off-site disposal, the removal action could begin in late May 1999 and be completed in about two weeks.

4. Alternative Actions Considered

Anaerobic bioremediation technology has proven to be effective in removing toxaphene from soils. An anaerobic process was developed during the Navajo Sheep Dip Vat project where rapid removal of toxaphene from contaminated soils was demonstrated. The process has shown excellent performance at different sites having initial toxaphene levels ranging from 14 to 1500 mg/kg. Degradation levels ranged from 58 to 95 percent in 3 to 12 months. Biologically active soils from existing Navajo sites could be used to augument the degradation process and increase the effectiveness of the treatment. The treatment system would require the excavation of three treatment pits measuring 100 feet long, 20 feet wide and 7 feet deep.

B. Estimated Costs

The costs for the site were approximated as follows:

Cleanup Contractor Costs (ERCS) $ 200,000 Contingency 40,000 Cleanup Contractor Total 240,000

Total Federal Agency Costs 20,000 Total START Costs 60,000 Extramural Subtotal 320,000

Project Contingency 60,000 Total Extramural 380,000

EPA Total 20,000

Total Project Ceiling $ 400,000

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VII. IMPORTANT POLICY ISSUES

A. ARARs

In accordance with 40 CFR 300.415(i), this removal shall, to the extent practicable considering the exigencies of the situation, attain applicable or relevant and appropriate requirements under federal and state environmental laws.

Federal ARARs:

Potential federal ARARs include RCRA Land Disposal Restrictions (LDRs) and the Off-Site Disposal Policy. Although there are no federal ARARs that specify the cleanup level for toxaphene spills in soils, EPA Region 9 developed a risk-based soil cleanup goal of between 0.4 mg/kg and 40 mg/kg for the Navajo toxaphene removal sites. A treatment and cleanup goal of less than 25 mg/kg above 4 four feet in depth was achieved through treatability studies and established through a treatability variance. This cleanup goal was determined to be protective of public health and the environment.

EPA's Preliminary Remediation Goals (PRGs) can. be used to screen contaminants in evironmental media, trigger further investigation, and provide an initial cleanup goal if applicable. The PRG for toxaphene is 2.7 mg/kg in soil (industrial PRG) which would be a very conservative cleanup goal.

State ARARs:

The Arizona State Soil Remediation Standards Rule is not applicable to this site but may be appropriate for consideration. The soil remediation levels (SRLs) for toxaphene are 17 mg/kg (non­residential areas) and 4 mg/kg (residential, areas) . The SRL for toxaphene in residential soils would not appear to be applicable to this Site. EPA believes that the application of the industrial SRL . would be sufficiently protective of human health and the environment for current and future plan uses of the Site.

Clean-up Goal:

Although there is not a applicable federal or state ARAR which sets a clean-up standard for toxaphene-contaminated soils at this site, EPA believes the Arizona State SRL for toxaphene and other contaminants to be an achievable cleanup goal. For the contaminant of primary concern, toxaphene, EPA believes that most of the contaminated areas will be cleaned up to below 17 mg/kg, but any area with concentrations at 25 mg/kg or above will be re-excavated to reduce the concentration to below 25 mg/kg toxaphene. The following is a summary of Arizona SRLs for the pesticides of concern:

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Contaminant Arizona's Non-

Residential SRL

Contaminant Arizona's Non-

Residential SRL

Toxaphene 17 mg/kg Chlordane 15 mg/kg

4,4-DDT 56 mg/kg Methyl Parathion 170 mg/kg

4,4-DDE 56 mg/kg Malathion 14,000 mg/kg

4,4-DDD 80 mg/kg Guthion not listed

Dieldrin 1.2 mg/kg

In general, one foot of soil will be removed from the surface within the east and west aircraft turn-around areas. No surface soils need to be removed from the airstrip runway. Contaminated soils in the substation trench area will be excavated to various depths but not exceeding six feet in depth. EPA believes that this clean-up strategy will be sufficiently protective of human health, welfare and the environment.

VIII. RECOMMENDATION

This decision document represents the selected removal action for the Gila River Indian Community Toxaphene Site, near the City of Chandler, Arizona, developed in accordance with CERCLA as amended, and not inconsistent with the NCP. This decision is based on the Administrative Record for the Site.

Conditions at the Site meet the NCP Section 300.415(b) (2) criteria for a removal and I recommend your approval of the proposed removal action. The total project ceiling if approved will be $400,000. Of this, an estimated $24.0,000 comes from the Regional-removal allowance for extramural cleanup contractor costs.

felti -fak-r—- 5-13-^ Approval Signature . Date l~'

Disapproval Signature Date

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ATTACHMENT A

ADDENDUM TO THE ACTION MEMORANDUM

CONFIDENTIAL DO NOT RELEASE ENFORCEMENT SENSITIVE

1. PRP Search

On March 1, 1999, EPA began an investigation to determine who were the PRPs with regard to the pesticide contamination discovered at the Gila River Indian Community Toxaphene Site. Aerial photographs from the 1960's to 1990's clearly indicate an airstrip runway surrounded by farm land, open desert and encroaching residential and commercial development. The property where the Site is located is owned by the GRIC. The federal Trustee that administers this land is the Department of Interior Bureau of Indian Affairs. The BIA has an easement through GRIC land to re-build the Pima-Chandler electrical substation. The pesticide aerial applicator companies or individual crop dusters that may have been responsible for the pesticide contamination and the farmers who may have leased the land and given permission to these entities to construct and operate the airstrip have not been identified to date.

According to the BIA, there would be no records of permits, licenses or leases to pesticide aerial applicators for the airstrip operation during the suspected years of operation from the late 1950's to the early 1980's. BIA began to lease land to crop dusters in the mid 1980's. BIA may have records of business leases to farmers on alloted lands in the area. These records may be stored in the BIA Realty Office. These farmers, if they can be identified and are still alive, may have personal knowledge of crop dusters who used the airstrip and their operational practices. Tribal governmental officials have no knowledge of PRPs or the operational history of this airstrip.

It was common practice for farmer(s) in the area to give permission to local crop dusters to construct airfields near agricultural farm land to reduce the distance the aircraft would have to travel to refuel and reload. This practice resulted in lower fuel costs which translated into reduced costs for pesticide aerial application. Many of the crop duster companies were stationed at the local municipal airports and it made economic sense to relocate fueling, mixing and loading facilities near the application sites. Many of these were mobile operations that involved dispatching tank pump trucks containing fuel and pesticides to the airstrip sites when needed. According to officials at the Chandler Municipal Airport, San Tan Dusters and K&K Applicators had facilities at the airport. Other local crop dusters that may have used the airstrip were Sanders Aviation and T&G Aviation. Large land owners and farmers in the area included the Thude and Dobson families.

During the investigation, EPA interviewed the following entities:

1. Michael Smith, Airport Operations Specialist, Chandler Municipal Airport (602)786-2864

2. Jim Weis, Environmental Coordinator, City of Chandler (602) 786-2303

3. Elbert Burns and Jim Garcia, Department of Public Works, City of Chandler (602) 786-2483

4. Ken Davis, Arizona Department of Agriculture (602) 542-4373

5. Pete Overton, BIA (520) 562-3372

6. Dale Anderson, Arizona Department of Environmental Quality (602) 207-4104

7. Dan Marsin, GRIC Department of Environmental Quality (520) 562-2234

8. Kris Carr, EPA Pesticide Project Officer for GRIC (415) 744-1099

9. Steve Lueck, Pacific Livestock Auction (602) 839-2938

10. Loretta Martinez, local resident (lives in trailer south of Site)

2. Notification of PRP Liability

EPA has not identified any PRPs to date. EPA believes that it is unlikely that any PRPs will be identified prior to initiation of the removal action. If PRPs are identified during the removal action, EPA will send a Notification of PRP liability and give them the opportunity to perform the removal action.

3. Decision Whether to Issue an Order

To date, EPA's investigation has not uncovered sufficient evidence that would warrant and substantiate the issuing of a Unilateral Administrative Order. Presently, EPA has requested the BIA to continue searching for records on farm leases in an attempt to locate a farmer with willingness to cooperate with EPA officials and provide names of individuals and companies that may have been involved with pesticide aerial application operations at the Site.

4. Enforcement and Cost Recovery

EPA believes it to be improbable that PRPs will be identified for possible enforcement action and cost recovery.