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Kanawha River Site

EPA Region 3 (Mid-Atlantic)

Kanawha & Putnam Counties
In the Vicinity of Nitro, WV


2nd Congressional District

Last Update: January 2009

Other Names


Current Site Status

In late 2008 and early 2009, Monsanto collected what should be the last of the fish and sediment samples in its study of dioxin contamination in a 14-mile stretch of the Kanawha River extending from the mouth of the Coal River to the Winfield Dam. The work is being conducted with EPA and West Virginia Department of Environmental Protection (WVDEP) oversight. This spring, Monsanto will prepare a risk assessment, a summary of all of the data and develop various potential ways to address the dioxin contamination for EPA and WVDEP to evaluate.

The state has established a fishing advisory in this area due to elevated levels of dioxin in fish. The advisory addresses the Kanawha River from the Interstate 65 bridge near St. Albans to the Ohio River and in the lower two miles of the Pocatalico River and the Armour, Heizer and Manilla Creeks.

This work is being conducted under an EPA Consent Order signed by Monsanto and Pharmacia Corporation in March 2004. Pharmacia was formerly known as the Monsanto Company (referred to here as Old Monsanto). The Monsanto Company (or New Monsanto) conducting work at the site was formed in 2000 and was spun off from Pharmacia.

Site Description

The Kanawha River Site is contaminated with dioxin generated from the past production of 2,4,5-trichlorophenol. The compound was then used to make the pesticide 2,4,5-trichlorophenoxyacetic acid or 2,4,5-T. The 2,4,5-T was produced from 1948 to 1969 at Old Monsanto's Nitro, West Virginia, facility located along the banks of the Kanawha River.

In 1995, the operation and management of the Nitro facility were transferred to Flexsys America LP, a joint venture between Old Monsanto and Akzo Nobel. In 1997, Old Monsanto spun off its chemical businesses, including its interest in Flexsys and the Nitro facility to Solutia, Inc. ("Solutia"). Solutia became an independent company on September 1, 1997. On March 31, 2000, Old Monsanto changed its name to Pharmacia Corporation.

Solutia and Flexsys are currently undertaking a Corrective Action under the Resource Conservation and Recovery Act (RCRA) with oversight from EPA and WVDEP. The Corrective Action addresses soil and ground water contamination at the Nitro facility.

Although EPA is studying a 14-mile stretch of the Kanawha River from approximately Mile Point (MP) 46 to MP 32 near the Winfield Dam, dioxin contamination extends beyond the dam, at least in the surface water. The current study is focusing on the area near the Flexsys/Solutia plant because EPA believes it to be the greatest source of dioxin in the river.

Site Responsibility
This site is being addressed by Potentially Responsible Parties under an EPA Superfund Removal Order.
NPL Listing History
This Site is not on the National Priorities List (NPL).

Threats and Contaminants

Dioxin, mainly 2,3,7,8-tetrachlorodibenzo-p-dioxin (the most toxic form of dioxin), has been found in sediments, surface water and fish in the Kanawha River. The West Virginia Department of Natural Resources (WVDNR) has established a fishing advisory due to elevated levels of dioxin in fish in the Kanawha River (and backwaters) from the Interstate 64 (I-64) bridge at Dunbar (at or near the downstream end of the former Old Monsanto plant) to the Ohio River, and in the lower two miles of the Pocatalico River and the Armour, Heizer and Manilla Creeks. The advisory is a "do not eat" advisory for carp, catfish, suckers, and hybrid striped bass. In addition, there is a one meal/month limit on other species. The advisory is posted on websites for the West Virginia Department of Health & Human Resources and WVDNR.

A description of dioxin and its associated risk factors are available on the Agency for Toxic Substance and Disease Registry, an arm of the CDC, web site

Cleanup Progress

The Kanawha River, the Pocatalico River and Armour Creek were placed on the State of West Virginia's 303(d) list of water-quality impaired bodies for dioxin, and a Total Maximum Daily Load (TMDL) for dioxin was completed in September 2000. The applicable standards specify that the maximum allowable concentration of dioxin shall not exceed 0.014 picograms per liter (pg/L) in the Kanawha River, and 0.013 pg/L in the Pocatalico River and Armour Creek. The TMDL applies to the portion of the Kanawha River from where the Coal River enters the Kanawha River to the Ohio River, just over 45 miles downstream. The TMDL applies in the Pocatalico River and Armour Creek two miles upstream of where they each enter the Kanawha River.

As a result of the TMDL development, the EPA Region 3 Superfund program began evaluating potential dioxin sources and conducting further sediment sampling. Sediment sampling conducted in May 2000 showed dioxin hotspots in what is now the study area.

In March 2004, EPA, Monsanto and Pharmacia entered into an Administrative Order on Consent to conduct an Engineering Evaluation and Cost Analysis (EE/CA) on dioxin-contaminated sediment at the Kanawha River Site. The goal of the EE/CA is to characterize the nature and extent of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) contamination in the Kanawha River Site that has been and/or is currently being released from what is now the Flexsys plant. TCDD is the most toxic form of dioxin. The EE/CA will also evaluate removal alternatives, if necessary, that will protect public health, welfare, and the environment.

In October 2004, Monsanto began field work to study dioxin contamination in a 14-mile stretch of the Kanawha River extending from the mouth of the Coal River to the Winfield Dam, which EPA identifies as the Kanawha River Site. Catfish, bass and forage fish samples, as well as surface water and sediment samples, were collected. Monsanto also mapped the river bottom in the study area. Surface water samples were collected in the spring of 2005. In November 2007, Monsanto and its consultant Conestoga-Rovers & Associates (CRA) began Phase II of their Extent of Contamination activities for the Site, which included sediment sampling to further define areas of contamination.

EPA and WVDEP have also undertaken a number of activities that will help control releases of dioxin to the Kanawha River. These include work at the Heizer Creek and Manilla Creek landfills and a number of landfills in the State's Landfill Closure Assistance Program (LCAP).


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