U.S. EPA Proposes Cleanup Plan for

Off-site Groundwater Contamination

Dover Chemical Site Dover, Ohio June 2015

Share your opinion The U.S. Environmental Protection Agency, working with the Ohio EPA, is U.S. EPA invites you to participate proposing a cleanup plan for contaminated groundwater associated with the Dover in the cleanup process at the Dover Chemical site. The mass, or plume, of contaminated groundwater extends off-site to Chemical site. Your input helps U.S. the southeast. (See site map, Page 3.) EPA determine the best way to clean up the off-site groundwater The contamination consists of volatile organic compounds, or VOCs – primarily contamination. chlorobenzenes – used in manufacturing. Dover Chemical Corp. will perform the cleanup under federal and state agency supervision. You may comment on the proposed plan from June 22 to July 22: The proposed cleanup consists of: • Orally or in writing at the public • Injecting oxygen-containing chemicals underground into an area near the meeting (see below). original off-site plume, where sand and gravel material may have absorbed • Fill out and mail the enclosed some contamination from the site. The sand and gravel continue to release comment form, or submit it at chemicals into the off-site groundwater, essentially acting as another source the meeting. of pollution. Injecting oxygen will help reduce the pollutants. • Online at www.epa.gov/ • Injecting oxygen and micronutrients into the plume. This will feed the region5/cleanup/dover. existing subsurface bacteria that breaks down the pollution. • Using natural means to prompt a variety of physical, chemical or biological Public meeting processes that reduce contaminants in the groundwater. There will be a public meeting Thursday, June 25, at 6 p.m.: All of the cleanup alternatives are explained, beginning on Page 2. Dover Public Library 525 N. Walnut St. Your comments are needed Dover U.S. EPA will review all comments received during the public comment period 1 before making a final decision on a cleanup plan. (See box, left, for ways you can Contact information participate in the decision-making process.) The Agency may modify the proposed If you need special accommodations cleanup plan or select another option based on new information or public comments, to attend the meeting or have so your opinion is important. questions, contact one of these team members: This proposed plan fact sheet gives you background information, describes cleanup options and explains U.S. EPA’s recommendation. You can find more details in a Ginny Narsete document called the Feasibility Study Addendum II, available on the Web and at the Community Involvement local information repository (see box, Page 8). We encourage you to review and Coordinator comment on the proposed cleanup plan. 312-886-4359 [email protected] U.S. EPA will respond to comments in a document called a “responsiveness summary.” This will be part of another document, the “record of decision,” that describes the final cleanup plan. The Agency will announce the final cleanup plan in Linda Martin the Times Reporter, place a copy in the information repository and post it on the Web. Remedial Project Manager 312-886-3854 [email protected] 1 Section 117(a) of the Comprehensive Environmental Response, Compensation, and Liability Act (CERLCA) requires publication of a notice and a proposed plan for the site cleanup. The Call U.S. EPA’s Chicago office proposed plan must also be made available to the public for comment. This proposed plan is a summary of information contained in the remedial investigation, feasibility study, the Feasibility toll-free at 800-621-8431, Study Addendum II and other documents in the administrative record for the Dover Chemical site. 9:30 a.m. – 5:30 p.m. weekdays. Please consult those documents for more detailed information. All official site documents can be found at the repository at the Dover Public Library, or online at www.epa.gov/region5/cleanup/dover. Proposed cleanup alternatives contamination levels by feeding the bacteria that break A total of four alternatives were considered: down the contamination. This alternative would be implemented in a phased approach. The initial phase Alternative 1: No action. would consist of the injections into the secondary source The “no action” alternative is always evaluated to area. This phase would include at least one round (or establish a baseline for comparison. Under this more if necessary) of injections and continued alternative, the federal agency would take no action to groundwater monitoring in the off-site plume. After a clean up the off-site groundwater plume. minimum of four rounds of quarterly monitoring, Estimated Cost: $0 conditions in the off-site plume would be reviewed in order to determine when to begin the injections of the Alternative 2: Monitored natural attenuation. oxygen and micronutrients into the heart of the plume. This alternative relies on natural processes to achieve Estimated Cost: $7.4 million site-specific cleanup objectives in a timeframe that is reasonable compared to other methods. Natural Alternative 3C – ISCO plus reductive dechlorination attenuation induces a variety of physical, chemical or followed by monitored natural attenuation. biological processes that act without human intervention This alternative is similar to Alternative 3B in that it to reduce the mass, toxicity, mobility, volume or combines Alternative 2 – monitored natural attenuation concentration of contaminants in groundwater. – with chemical injections at the secondary source area Estimated Cost: $1.8 million as described in Alternative 3A as well as injections into the plume. However, in this alternative, the injections Alternative 3A – In-situ chemical oxidation, or ISCO, into the heart of the plume would contain a hydrogen- within the injection grid, followed by monitored containing compound to enhance anaerobic conditions in natural attenuation in the heart of the plume. the groundwater to reduce the chlorinated benzene levels This combines Alternative 2 – monitored natural through anaerobic biodegradation. While oxygen helps attenuation – with injecting an oxygen-containing some bacteria break down contamination, other bacteria chemical in an area near the origin of the off-site plume work better without oxygen, in “anaerobic” conditions. where the subsurface sand and gravel has absorbed some Adding hydrogen helps these other bacteria break down contamination from the site. This contaminated sand and the contamination. gravel is continuing to contribute to the pollution of the off-site groundwater, essentially acting as a secondary This alternative would be implemented in a phased source of pollutants. This option involves injecting approach. The initial phase would consist of the oxygen into the sand and gravel to help reduce the injections into the secondary source area. This phase contamination at this subsurface location and ultimately would include at least one round (or more if necessary) throughout the plume as groundwater flows away from of injections and continued groundwater monitoring in the site. Oxygen feeds the bacteria that break down the the off-site plume. contamination. Additional injections would be performed as necessary until the sand and gravel pollution is no After a minimum of four rounds of quarterly monitoring, longer causing additional contamination of the conditions within the off-site plume would be reviewed groundwater. The remaining portion of the off-site plume in order to determine when to begin the injections of the would be degraded via monitored natural attenuation hydrogen into the plume. processes as explained in Alternative 2. Estimated Cost: $7.2 million Estimated Cost: $4.8 million Alternative 4 – Pump and treat by air stripping off- Alternative 3B – ISCO site. plus aerobic amendments U.S. EPA’s recommended This alternative includes the installation of three followed by monitored alternative pumping wells and a treatment building in a location off- natural attenuation. site near the plume and treating the contaminated water This alternative combines Alternative 2 – monitored with a process called air stripping. The treated water natural attenuation – with oxygen injections at the would then be discharged to Sugar Creek. Air stripping secondary source area as described in Alternative 3A as exposes contaminated water to air, causing contaminants well as injections of oxygen and micronutrients in the water to evaporate. The air is then treated with throughout the plume to enhance aerobic, or oxygenated, carbon filters before being released. conditions in the groundwater. This reduces the Estimated Cost: $12.5

2

Evaluation of alternatives U.S. EPA is required to evaluate these alternatives against nine and 2 would not comply in the foreseeable future as the current criteria (see box, Page 4). The criteria are used to help compare contaminant levels would remain. Alternative 3A would how the options will meet cleanup goals. The table on Page 4 achieve compliance more quickly than Alternative 2 because of compares each alternative against the nine criteria. the injections. Alternatives 3B and 3C would comply in about five to 10 years following the completion of injections because Alternatives 3A, 3B, 3C and 4 would protect human health and of the additional injections. Alternative 4 is expected to comply the environment, while Alternative 1 would not as it would do in 20 to 144 years. nothing to treat, remove, or isolate the contaminated groundwater and would not be monitored. Alternative 2 may U.S. EPA’s recommended alternative protect human health and the environment. However, it is U.S. EPA, in consultation with Ohio EPA, uncertain how long it would take to achieve cleanup objectives recommends Alternative 3B because it provides and it is unlikely it would do so in a reasonable amount of time. the best balance of eight of the nine criteria. While there are no current human exposures identified with the Community acceptance will be evaluated after the groundwater, Alternatives 1 and 2 could produce exposure public comment period. issues in the future. Alternative 3B provides the best, cost-effective Alternatives 3A, 3B and 3C all would comply with applicable cleanup solution and the best protection of people or relevant and appropriate requirements. However, time and the environment. It will take the least amount periods required to meet the requirements vary. Alternatives 1 of time to reach the cleanup goals. And, the alternative satisfies U.S. EPA’s preference for using treatment to clean up a site.

3 Alternative 1 would not meet the long-term effectiveness destruction of contaminants within the treated portions and permanence criterion. Alternatives 3A, 3B and 3C of the plume. Evidence shows the plume is not growing, would achieve long-term effectiveness and permanence so mobility is not a significant factor. Alternative 4 through eventual complete destruction of the would reduce the volume of contaminated groundwater contaminants within the off-site plume. Alternatives 2 because it will be extracted and treated. Alternatives 3A, and 4 would eventually achieve long-term effectiveness 3B, 3C and 4 satisfy U.S. EPA’s preference for using and permanence, but it would take longer than with treatment to clean up a site. Although, 3A only uses Alternatives 3A, 3B and 3C. treatment in the secondary source area.

No reduction of toxicity, mobility or volume would be Alternatives 1 and 2 would not be effective in the short provided by Alternative 1 as the off-site plume would term as no action would be taken to alter current remain. Alternative 2 would provide for the reduction of conditions. Alternative 2 includes monitoring the toxicity and volume of contaminants through natural groundwater to document the progress of naturally processes in the groundwater and would be monitored. occurring attenuation. Alternatives 3A, 3B and 3C will Alternatives 3A, 3B and 3C would reduce toxicity and provide effectiveness in a shorter amount of time. volume of contaminated groundwater due to the

4 Public Comment Sheet

Use this space to write your comments U.S. EPA is interested in your comments on the proposed cleanup plan for off-site groundwater contamination at the Dover Chemical site. You may use the space below to write your comments. Submit them at the June 25 public meeting, or detach, fold, stamp and mail to U.S. EPA Community Involvement Coordinator Ginny Narsete. Comments must be postmarked by July 22. If you have questions, contact Ginny at 312-886-4359, or toll-free at 800-621-8431, Ext. 64359, 9:30 a.m. – 5:30 p.m., weekdays. You may also comment at www.epa.gov/region5/cleanup/dover.

Name: Affiliation: Address: City: State: Zip:

Dover Chemical Site – Comment Sheet

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Detach this page, fold on dashed lines, staple, stamp, and mail ------

Name Address City State Zip

Ginny Narsete Community Involvement Coordinator U.S. EPA Region 5 Superfund Division (SI-7J) 77 W. Jackson Blvd. Chicago, IL 60604-3590

Alternative 4 would take longer to install and Chemical are undeveloped property in the residential implement. It would be less effective in the short term. area to the east of the facility, and undeveloped property between I-77 and Sugar Creek. The property west of I- All the alternatives are implementable. Alternatives 1 77 contains an 8-acre pond – referred to as the “lagoon” and 2 would be the most readily implementable. – which is up to 28 feet deep and was formerly a borrow Alternative 3A would be a little more difficult to pit used during the construction of I-77. implement as an access agreement would be required for activities outside the Dover Chemical Plant boundaries. Dover Chemical has operated a manufacturing facility at Alternatives 3B and 3C would be slightly more difficult the site since 1950. The facility produces extreme to implement relative to Alternative 3A as more access pressure lubricants, plasticizers and flame retardants that agreements would be required. Alternative 4 would be go into vinyl products. Site activities from the 1950s to the most difficult to implement because, in addition to the early 1970s introduced contaminants into soil and numerous access agreements, this alternative requires groundwater in the vicinity of the Dover Chemical plant. permitting and construction activities. Investigations at the site confirmed the presence of The costs are listed in the table on Page 4. The state of VOCs, as well as dibenzofurans, or furans, and Ohio supports U.S. EPA’s recommended alternative. polychlorinated dibenzodioxins, more commonly known Community acceptance will be evaluated after the public as dioxin, in on-site soil and groundwater. comment period. Soil and sediment cleanup Off-site groundwater investigation Based on the results of a 1991investigation called a The off-site groundwater plume is contamination that remedial investigation/feasibility study, U.S. EPA asked separated from the plant-area groundwater plume. It is Dover Chemical to reduce the potential movement of the focus of this cleanup. The contamination in the off- contamination and the potential for contact with soil site groundwater consists of VOCs, primarily containing dioxin and furans. The soil cleanup included chlorobenzenes. removing contaminated soil above levels considered acceptable for a residential area, restricting access to Between 2000 and 2008, Dover Chemical worked with portions of the site, and removing dioxin/furan U.S. EPA and Ohio EPA to better define the off-site contaminated soil in all off-site areas. The cleanup of groundwater plume with the addition of more contaminated soils on-site was completed in September groundwater monitoring wells and the negotiation of a 2010. long-term groundwater monitoring plan to collect groundwater samples quarterly. The work completed by On-site groundwater cleanup Dover Chemical indicates that: A plume of contaminated groundwater underneath the • The off-site groundwater plume is stable and not actual plant area is being cleaned up by a pump-and-treat expanding. system that has been in operation since 1988. Over the • Contaminated groundwater is no longer moving years, the groundwater pump-and-treat system has been off-site. enhanced with the addition of new extraction wells to • Natural attenuation is occurring in the help capture the VOC- and dioxin-contaminated on-site groundwater. groundwater. The extracted groundwater is treated by air • Modification of conditions in the off-site plume stripping to remove VOCs before discharge to Sugar could speed up the natural processes and help Creek in accordance with a National Pollution Discharge reduce contaminant concentrations within the Elimination System permit. plume. In 2012, Dover Chemical installed groundwater Background monitoring wells to verify the existing groundwater The Dover Chemical Corp. is just off of Interstate 77 at pumping is effectively preventing contaminated Davis Street and West 15th Street. The company owns groundwater from leaving the site. The results of this three parcels of land near the Dover city limits that total monitoring has shown it is working. 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 7

For more information You may review site-related documents at:

Dover Public Library 525 N. Walnut St. Dover

On the Web, visit: www.epa.gov/region5/cleanup/dover An administrative record, which contains detailed information that will be used in the selection of the cleanup plan, is also located at the library.

Contamination Groundwater site - Off for Plan Cleanup Proposes EPA U.S.

SITE: CHEMICAL DOVER