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Coronet Industries


Aerial photo of Coronet site.

Additional Resources
Site Summary Profile
EPA ID: FLD001704741
Location: Plant City, Hillsborough, FL
Lat/Long: 27.979586, -082.077685
Congressional District: 09
NPL Status: Superfund Alternative Site
Affected Media: Ground water, surface water, sediment, soil
Cleanup Status: Iinvestigation is underway
Human Exposure Under Control: NA
Groundwater Migration Under Control: NA
Sitewide Ready for Anticipated Use: NA
Site Reuse/Redevelopment: Portions of site in continued use, other portions not currently in use – potential redevelopment options for these areas are being evaluated
Site Manager: Brad Jackson (jackson.brad@epa.gov)

Current Site Status

The Coronet Industries site includes a large area affected by mining and chemical plant operations. Mining operations ended around 1940 and chemical plant operations ended in 2004. EPA did not list the site on the National Priorities List (NPL) but considers it an NPL-caliber site and is addressing the site through the Superfund Alternative Approach because of contaminated ground water, surface water, sediment and soil resulting from past plant operations. EPA, the Florida Department of Environmental Protection (FDEP) and Coronet Industries, Inc., a potentially responsible party (PRP), have investigated site conditions and taken steps to clean up the site in order to protect people and the environment from contamination. Site contamination does not currently threaten people living and working near the site. Both residents and businesses use the public water system for drinking water. By investigating site conditions and cleaning up the site, EPA, FDEP and the site’s PRP continue to protect people and the environment from site contamination.

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Site Location and Background

The 2,500-acre site is located east of Plant City, Florida, and includes a 980-acre parcel, a 1,365-acre parcel and a handful of smaller parcels occupied by operating businesses. The site also includes a former phosphate rock mine and chemical plant. The site’s surroundings include U.S. Highway 92 to the north, Park Road to the west, Coronet Road to the south and Lexie Lane to the east. A farm is located east of the site. Scattered rural residences and commercial businesses are located to the north. Higher-density urban areas are located to the west and immediately south of the site and include low-income and minority residents.

The Coronet Phosphate Company (separate from Coronet Industries, Inc.) began mining operations at the site in 1906 and conducted phosphate mining operations on portions of the site until about 1940. The company deposited mining wastes that contained smaller particles of phosphate rock, sand and clay on several areas at the site, including the land surface, pond bottoms and construction sub-base. A chemical plant added in 1946 produced a nutritional animal feed supplement (coronet defluorinated phosphate, or CDP). The company added another product line (potassium fluoroborate, or KBF4) in 1958. Coronet Industries, Inc. purchased 980 acres of the site in 1993, which consisted mainly of the chemical plant and wastewater management system. Operations at the chemical plant ended in 2004. Parties eventually removed several large industrial structures associated with the chemical plant.

EPA did not list the site on the NPL, but considers it an NPL-caliber site and is addressing the site through the Superfund Alternative Approach. This approach uses the same investigation and cleanup process and standards used for sites listed on the NPL. Active businesses continue to operate on site. Parties are evaluating redevelopment opportunities for portions of the site that are not in use.

View site map.

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Threats and Contaminants

Site investigations identified contamination in ground water, surface water, sediment and soil that could potentially harm people in the area. Contamination resulted from manufacturing and mining practices at the site. Contaminants of concern identified at the site include arsenic, boron, fluoride and sodium, as well as radiological contaminant (radionuclides, or unstable radioactive material) radium-226, potassium-40 and polonium-210.

The PRP found several inorganic and radioactive substances in ground water at the site, including acidic ground water in the former chemical plant area. The PRP found site-related contaminants in surface water, pond sediments and, to a lesser extent, in nearby English Creek. It is possible that a trespasser or worker could come in contact with soil-related contamination. However, most of the site is fenced and secured.
Residents and workers use the public water supply for drinking water, which is not affected by site contamination. Vapor intrusion is not a threat.

The Agency for Toxic Substances and Disease Registry (ATSDR) conducted multiple studies during 2003 and 2004 to evaluate potential health effects of site contamination. The studies evaluated health effects through analysis of urine samples, drinking water samples, soil samples, fish samples and air samples. ATSDR also evaluated cancer data from 1990 to 2000. ATSDR concluded that, based on the study results, the site’s contamination posed “no apparent public health hazard.” Because of limited data, ATSDR could not make a determination regarding potential health effects from people’s potential past contact with site-related contamination

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Investigation and Cleanup Responsibility / Oversight

The site’s PRP leads investigation and cleanup activities for a portion of the site, with oversight provided by EPA and FDEP.

EPA conducted studies at the remaining portion of the site and is currently identifying additional PRPs to undertake the remaining work.

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Site Cleanup Plan

Site investigations and cleanup activities have focused on two areas, which EPA refers to as operable units, or OUs. These areas include OU-1: Coronet Industries, Inc.; and OU-2: Lakeside Station.

OU-1 includes the 980-acre area in the southeast portion of the site; the former chemical plant, several ponds and ditches, and a former golf course are located in OU-1.

OU-2 includes a 1,365-acre parcel of formerly mined land along the northern and western portions of the site; several water-filled mine pits, mine spoil disposal areas and areas disturbed by former mining operations are located in OU-2.

The draft August 2010 Remedial Investigation (RI) Report for OU-1 summarized findings for ground water, soil, surface water and sediment as well as the results of human health and ecological risk assessments. The report was reviewed and revised based on comments from EPA and FDEP.  The RI Report was approved in December 2013 and the next step in the process is the evaluation of potential cleanup options.

In January 2011, EPA conducted a study of OU-2 that used an innovative radiation survey reliant on remote sensing instead of traditional soil sampling to identify areas impacted by past mining activities. The study approach enabled EPA to examine a large area (approximately 1,500 acres) over a two-week period. Following the study, however, EPA concluded that no further work under CERCLA was need at this time. EPA advised the property owner that future development of the property should be conducted in accordance with applicable State and local regulations.

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Cleanup Progress

In 2007, Coronet Industries, Inc., the PRP for OU-1, completed the closure of Pond 6, which was in danger of overflowing. The PRP drained the pond of acidic wastewater, consolidated waste material in the pond and installed an engineered cap. The PRP also installed a ground water collection and disposal system, as ordered by FDEP. The system collects ground water via a horizontal well around the edge of the pond and pumps it to on-site ponds.  Water is treated and discharged to English Creek as authorized by a Florida Industrial Wastewater Facility Permit (FL0034657).  

With the approval of the RI Report, the next step in the cleanup process will be the evaluation of potential cleanup options.

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Enforcement Activities

EPA negotiated legal agreements with the site PRP for OU-1 to investigate and clean up OU-1. The PRP continues to fund site cleanup, monitoring and oversight activities for OU-1. EPA is currently working to identify potentially responsible parties for OU-1.

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Community Involvement

EPA is working with the community and its state partner to develop a long-term cleanup plan for the site, reflecting the Agency’s commitment to safe, healthy communities and environmental protection. Community engagement and public outreach are core components of EPA program activities.

EPA has conducted a range of community involvement activities to solicit community input and to make sure the public remains informed about site activities throughout the cleanup process. Outreach efforts have included public notices and information meetings on cleanup progress and activities.

A Technical Assistance Plan (TAP) for the site supports community outreach and engagement. PRPs fund TAPs as part of negotiated settlement agreements. In 2010, the Improvement League of Plant City (ILPC) received a TAP grant to support the community’s participation in the OU-1 cleanup process. EPA has met regularly with the ILPC to provide project updates and obtain input from the community.

EPA has hosted public meetings to discuss investigation and cleanup activities for both OUs. EPA may host additional meetings in the future to keep the public updated regarding ongoing Superfund activities at the site.

Fact Sheets

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Future Work

The PRP will conduct the feasibility study for OU-1 after completing the RI Report.


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Additional Information

EPA keeps additional site documents and information in a site information repository at the location below. EPA also posts site documents, when available, on EPA’s CERCLIS Site Profile page. For documents not available on the website, please contact the Region 4 Freedom of Information Office.

Site Repository

Bruton Memorial Library
302 W. McLendon Street
Plant City, Florida  33563

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