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Congressional District # 18


EPA ID# OHD004210563
Last Updated: April, 2015

Site Description

The Dover Chemical Corporation is located just off of Interstate 77 (I-77) at Davis Street and West 15th Street, Tuscawaras County, Dover, Ohio. Dover Chemical owns three parcels of land near the Dover city limits that total approximately 60 acres. The chemical manufacturing facility, located on the 20-acre main parcel, is bounded on the west by I-77, on the south by industrial property, on the east by a railroad line, and on the north by an open field. The remaining parcels owned by Dover Chemical are undeveloped property in the residential area to the east of the facility, and undeveloped property between I-77 and Sugar Creek. The property west of I-77 contains an 8-acre pond (referred to as the "lagoon"), which is up to 28 feet deep and was formerly a borrow pit used during the construction of I-77.

Dover Chemical has operated a manufacturing facility at the site since 1950. The facility produces products that are used to manufacture extreme pressure lubricants, plasticizers, and flame retardants for vinyl products. Site activities from the 1950s to the early 1970s introduced contaminants into soil and ground water in the vicinity of the Dover Chemical plant. The contaminants entered the environment through a low-lying area in the southwest corner of the facility (also known as Area H), through the temporary storage of chemicals on the ground next to Building 21, and through unintentional process spills and leaks. Area H is believed to have been the principal source of contaminants in soils and ground water at the facility.

Since the mid-1980s , the on-site groundwater contamination has been contained by the pumping of on-site production wells, which generate more than 1 million gallons per day of non-contact cooling water for the plant. Until 1987, waste water from the plant was discharged via a ditch known as the "canal" through the lagoon, which ultimately discharged to Sugar Creek. Actions were taken in 1987 and 1988 under the direction of Ohio EPA Pollution Discharge Elimination System (PDES) to improve waste-water treatment. In 1987, as part of treatment system upgrades, treated water was redirected through a pipe directly to Sugar Creek, thus bypassing the canal and lagoon. The lagoon water was pumped and treated on-site prior to discharge to the Sugar Creek. As a result, site contaminants previously found in the lagoon surface water and the adjacent shallow ground water at low concentrations are no longer present.

Several environmental investigations were conducted at Dover Chemical to assess the extent and potential impact of contaminants that were inadvertently released to the environment. A number of interim clean-ups and other steps have been taken at the site to reduce the risk posed by the contaminants. These investigations and actions have been conducted with the concurrence and oversight of  EPA Region 5 and the Ohio EPA.

Site Responsibility

This site is being addressed by Dover Chemical under Federal Administrative Order on Consent. 

Threats and Contaminants

Investigations conducted at the site confirmed the presence of volatile organic compounds (VOCs) in soil and ground water, and also identified the presence of additional site-related constituents such as carbon tetrachloride, 1,4-dichlorobenzene, hexachlorobenzene, tetrachloroethene, dibenzofurans (furans), and polychlorinated dibenzodioxins (more commonly known as dioxin). Although these and other chemicals have been found at the site, dioxin contamination poses the greatest risk.

Information gathered from all of the investigations conducted at this site have identified four areas of concern. These areas are: Plant area soil--includes all soil located in the production area as well as soil in the unused portions of the immediate plant area. Lagoon and canal area soil and sediment--the area west of I-77, where the plant lagoon is located. Plant area ground water--a plume of ground-water contamination currently found underneath the plant area. As mentioned above, this contamination is currently being contained and removed by the existing production wells and waste-water treatment system.

Off-site ground water plume--contamination that separated from the plant area groundwater plume. The primary contaminate of concern in the off site groundwater plume is chlorobenzene contamination. The Agency is currently reviewing options and will propose an alternative to address this problem in the summer of 2015.  

Cleanup Progress

Based on the Remedial Investigation/Feasibility Study (RI/FS) investigation results in 1991, EPA requested that Dover Chemical take interim actions to reduce the mobility and potential for contact with soil containing dioxin and furans. This action was taken to reduce the potential risk to workers from direct contact with on-site soils contaminated with dioxin and furans at the site.

The interim soil clean-up action taken to reduce direct human exposure included removing contaminated soil above residential clean-up levels, restricting access to portions of the site, and removing dioxin/furan contaminated soil in all off-site areas. The final removal action to remove contaminated soils onsite was completed in September 2010.  

Dover Chemical has completed the installation of additional groundwater monitoring wells to better define the off-site groundwater plume associated with activities at the Site. These wells are being sampled on a quarterly basis. This data is being used to evaluate remedial options for addressing the off site plume.  A Feasiblity study addendum was completed in May 2013.  The Agency is currently working on a Proposed Plan/ROD to determine what action should be taken to address the off site groundwater plume.

The current groundwater extraction system that is addressing the on site groundwater contamination, was enhanced with the addition of three new extraction wells to help improve cleanup times.  Excavation and off-site disposal of Lagoon Area Soils and Canal Sediments. Soils are being cleaned to 10 parts per billion (ppb) TEQ dioxin/furan. The installation of a barrier around the lagoon area and implementation of institutional controls were also completed for the site as part of the response action. The institutional controls provide for access restriction, and limit the future use of the site to industrial activities only. Further optimazation of this on site groundwater system is being evaluated at this time. Additional monitoring wells have been installed and the groundwater on site is currently captured and is not longer moving off site and contributing to the off site groundwater contamination problem.  

Property Reuse

The property is currently an active chemical manufacturing facility.


Remedial Project Manager, U.S. EPA
linda martin (martin.lindab@epa.gov)
(312) 886-3854

Community Involvement Coordinator, U.S. EPA
susan pastor
(312) 353-1325




Site Profile Information

This profile provides you with information on EPA's cleanup progress at this Superfund site.


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