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EPA in Missouri

Syntex Facility National Priorities List (NPL) Superfund Site, Verona, Lawrence County, Missouri - Fact Sheet, November 2019

EPA Announces Public Availability Session


EPA is currently overseeing work conducted by the Potentially Responsible Party (PRP), required by the 2012 and 2017 Five-Year Reviews at the Syntex Facility National Priorities List (NPL) Superfund Site (site). Five-Year Reviews (FYRs) assess remedies to evaluate if they remain protective of human health and the environment. The 2012 Five-Year Review could not determine if the installed remedy remains protective. In 2016, EPA negotiated an agreement for the PRP to conduct additional investigations to make that determination. The conclusions of the next FYR in 2017 were similar to those in 2012, since the additional investigations were ongoing. EPA continues to oversee the work required to make this determination.

It is not uncommon for FYRs to require additional information before making a protectiveness determination, and it does not necessarily indicate an increased health risk for those living and working near the site. Data collected since the 2012 FYR, including limited private well sampling, does not indicate exposure to site contaminants above a level of health concern.


The U.S. Environmental Protection Agency (EPA) Region 7 is hosting a Public Availability Session to provide a site update. EPA will provide information about ongoing and current activities at the site and technical assistance resources. After an EPA presentation, federal and state agency representatives will be available to discuss the site and answer questions from the public.

The session will be held:

Monday, Nov. 18, 2019
6 to 8:30 p.m.
Verona High School Cafeteria 
101 E. Ella St.
Verona, MO 65769


EPA is committed to providing reasonable accommodations to individuals with disabilities. For reasonable accommodations at the Public Availability Session, please contact Jonathan Cooper by email at or toll-free at 1-800-223-0425. Speech- or hearing-impaired individuals should email or call using the local relay service.


The site covers approximately 180 acres and is located on 299 Extension Street in Verona, Lawrence County, Missouri. The site is currently divided into two areas, the East Area and the West Area, which are divided by the Spring River. In the past, Syntex and several companies produced Agent Orange (or hexachlorophene) at the site, contaminating groundwater and soil with dioxin and volatile organic compounds (VOCs).

Ongoing federal and Potentially Responsible Party actions have been taken to address and monitor contamination at the site. The eastern portion of the former Syntex facility is now owned and occupied by BCP Ingredients Inc.


Before industrial operations, the site was used for agricultural and recreational purposes. In the 1960s, Hoffman-Taff Inc. owned and operated the facility. Hoffman-Taff produced 2,4,5-trichlorophenoxy-acetic acid (2,4,5-T) for the U.S. Army, as part of the production of the defoliant commonly referred to as Agent Orange.

In 1969, Hoffman-Taff leased a portion of the facility to Northeastern Pharmaceutical and Chemical Company (NEPACCO) for the production of hexachlorophene. Between 1969 and 1972, NEPACCO operated a soap production facility on site.

In 1969, Syntex Agribusiness Inc. (Syntex) purchased the facility from Hoffman-Taff for chemical manufacturing and allowed NEPACCO’s lease to remain in effect.

Dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin), also known as or 2,3,7,8-TCDD, was created as an unwanted by-product in the production of 2,4,5-T and hexachlorophene, and dioxin residues were disposed of in several areas at the facility, contaminating soil and groundwater with dioxin and VOCs. Fish in the downstream Spring River were also contaminated.

Dioxin, a persistent organic pollutant, is considered by EPA to be an extremely toxic contaminant. Chlorinated dibenzo-p-dioxins (CDDs) are a family of 75 chemically-related compounds, commonly known as chlorinated dioxins. One of these compounds is 2,3,7,8-TCDD. It is one of the most toxic of the CDDs and is the one most studied.


EPA added the Syntex facility to the Superfund program’s National Priorities List (NPL) in 1983. The NPL is a list of the nation’s hazardous waste sites with the highest priority for cleanup.

In 1988, EPA selected the remedy for dioxin-contaminated soils and equipment. The remedy included excavation and off-site thermal treatment of dioxin-contaminated soil; dismantling and decontamination of equipment; capping and covering of the trench area; and backfilling and vegetating of contaminated areas. EPA removed contaminated soil and equipment, and capped and revegetated excavated areas.

In 1993, EPA selected a remedy of No Further Remedial Action for groundwater at the site, as off-site contamination was within the range of acceptable health-based standards. The groundwater assessment was based on water quality sampling from monitoring wells installed on the site. The remedy included continued groundwater monitoring and surface water sampling of the Spring River.

Additional information about the site, including site background, human and ecological impacts, and information on the contaminants of concern, is referenced in the Additional Information and About the Contamination sections below.


The Potentially Responsible Party (PRP), under the terms of the 2016 agreement, has submitted several workplans and received EPA approval to perform additional characterization of soil, sediment and groundwater at the site.

This includes the following:
  • Installation of new sampling wells
  • Groundwater sampling in the East and West Areas
  • Soil sampling in the East Area for dioxin and dioxin-like compounds
  • Sediment sampling of the Spring River

The workplans also include a reassessment of human health and ecological risk using current methodology, assumptions, and toxicity values.

In 2017, with oversight from EPA, the PRP began conducting the characterization described in the workplans. EPA will provide updates regarding the work being performed in subsequent fact sheets as more information becomes available.

On Jan. 9, 2019, an Environmental Covenant covering the East Area went into effect. The Covenant assures that any future construction or repair activities will be conducted in a manner that is protective of human health and the environment.

The Covenant also requires the property owner to sample and assess the soils for dioxin and dioxin-related compounds, as well as polychlorinated biphenyls (also known as PCBs), prior to excavation or disturbance. It requires proper maintenance of asphalt and concrete-covered areas. Additionally, it prevents groundwater use.


In an effort to help affected communities understand the technical information related to a Superfund site, EPA has established a Technical Assistance Grant (TAG) Program. The program provides up to $50,000 for a qualified citizens’ group to hire an independent technical advisor. The advisor can assist citizens in their interpretation of technical data, site hazards, and the different scientific technologies used to support site actions. (For more information, see EPA Contact Information.)


EPA has assessed the ability of the public to access the Administrative Record file and Five-Year Reviews through an internet‐based repository and has determined that the local community has this ability. As a result, site information is available on EPA’s website. Additional information regarding Five-Year Reviews is also available on EPA’s website.


For more information about dioxin health risks, visit the CDC/ATSDR ToxFAQs™. Learn more about dioxin on EPA’s website.


EPA and the state encourage members of the community to ask questions and report any concerns about the site. If you have questions about this Fact Sheet, need additional information about the site, and/or would like to receive site updates, please contact EPA:

Elizabeth Kramer
Community Involvement Coordinator
U.S. EPA Region 7
11201 Renner Boulevard
Lenexa, KS 66219
Phone: 913-551-7186
Toll-free: 1-800-223-0425
Brian Zurbuchen, Ph.D.
Remedial Project Manager
U.S. EPA Region 7
11201 Renner Boulevard
Lenexa, KS 66219
Phone: 913-551-7101
Toll-free: 1-800-223-0425