FINAL PLAN OF REMEDIAL ACTION

14028 Sussex Highway Greenwood, Delaware

14028 Sussex Highway

June 2018 DNREC Project No. DE-1651

This Final Plan of Remedial Action (Final Plan) presents clean-up actions required by the Department of Natural Resources and Environmental Control (DNREC) to address environmental contamination at the 14028 Sussex Highway Site.

DNREC issued a public notice of the Proposed Plan of Remedial Action (Proposed Plan) for the Site on May 6, 2018 and opened a 20-day public comment period. The Proposed Plan is attached. There were no comments from the public; therefore, the Proposed Plan is adopted as the Final Plan.

Approval: This Final Plan meets the requirements of the Hazardous Substance Cleanup Act.

KAD:gpb KAD 18020.doc DE 1651 II B 9

Date

inistrator Section

PROPOSED PLAN OF REMEDIAL ACTION

14028 Sussex Highway Greenwood, Delaware

DNREC Project No. DE-1651

May 2018

Delaware Department of Natural Resources and Environmental Control Division of Waste and Hazardous Substances

Site Investigation & Restoration Section 391 Lukens Drive

New Castle, Delaware 19720

CONTENTS

• Figures: I - 3

• Glossary of Terms

PROPOSED PLAN OF REMEDIAL ACTION

Approval:

14028 Sussex Highway Greenwood, Delaware

DNREC Project No. DE-1651

This Proposed Plan meets the requirements of the Hazardous Substance Cleanup Act.

Approved by:

Administrator

PROPOSED PLAN Questions & Answers 14028 Sussex Highway

What is the Proposed Plan of Remedial Action?

The Proposed Plan of Remedial Action (Proposed Plan) summarizes the clean-up (remedial) actions that are being proposed to address contamination found at the Site for public comment. A legal notice is published in the newspaper for a 20-day comment period. DNREC considers and addresses all public comments received and publishes a Final Plan of Remedial Action (Final Plan) for the Site.

What is the 14028 Sussex Highway Site?

The 14028 Sussex Highway site is located at 14028 Sussex Highway in Greenwood, Delaware, and consists of one tax parcel (530-14.00-12.00), totaling approximately 4.4 acres (Figure 1 ). The nearest intersection to the Site is Cart Branch Road and Sussex Highway. The Site consists of six ( 6) vacant structures (including a former automobile service/filling station/office building, a shop, a residential dwelling, and two storage buildings), asphalt paved surfaces, concrete covered surfaces, grass covered areas, and wooded areas. The Site is zoned commercial (Figure 2).

What happened at the 14028 Sussex Highway Site?

The Site has been developed since the early 1900s, and historically has been used as a residence, an automobile/filling station, and most recently for storage and distribution of steel building materials . The Site has been vacant since 2014. Previous investigations indicated that underground storage tanks (USTs) were historically present on the Site, and had been removed. The investigations also indicated the presence of organic compounds typical of a petroleum related release in soil and groundwater.

What is the environmental problem at the 14028 Sussex Highway Site?

A Brownfield Investigation performed in 20 17 at the Site found that the shallow groundwater (which ranges from approximately 2 feet below ground surface to approximately 8.5 feet below ground surface) contained contamination of volatile organic compounds (VOCs) including benzene, ethylbenzene, isopropyl benzene, toluene, xylene, and 1,2,4-trichlorobenzene; semi­volatile organic compounds (SVOCs) including naphthalene and 2-methylnaphthalene; pesticides including heptachlor epoxide; and, inorganic compounds including aluminum, arsenic, chromium, cobalt, iron, lead, manganese, and vanadium. Deep groundwater (approximately 160 feet below ground surface) contained contamination of vinyl chloride and dissolved lead. There is a potential risk to residential users, as well as indoor commercial workers due to possible ingestion of groundwater if cleanup actions are not taken. The vapor intrusion pathway for both residential users and indoor commercial workers was evaluated. The results determined an

unacceptable risk for residential and commercial use due to vapor intrusion in the area of Operable Unit 2 (OU-2) (Figure 3). However, further investigation was performed on the buildings within the footprint of OU-2, and it was determined that they do not pose an unacceptable risk for commercial use. Once the groundwater consumption pathway is removed or treated , Operable Unit I (OU-I) of the Site passes for a resident, indoor commercial worker, outdoor commercial worker, composite worker, excavation worker, recreational, and trespasser use scenano.

What clean-up actions have been taken at the 14028 Sussex Highway Site?

None.

What does the owner want to do at the 14028 Sussex Highway Site?

The Site will be redeveloped for mixed residential and commercial use.

What additional clean-up actions are needed at the 14028 Sussex Highway Site?

DNREC proposes the following remedial actions for Operable Unit 1 (OU-1) of the Site, which need to be completed before a Certificate of Completion of Remedy (COCR) can be issued.

I. A Remedial Action Work Plan must be submitted to DNREC for approval within 60 days of the issuance of the Final Plan of Remedial Action.

2. The deep groundwater well must have a treatment system installed and periodic monitoring pursuant to the schedule indicated in the DNREC approved Remedial Action Work Plan.

3. A proposed Environmental Covenant must be submitted to DNREC for approval within 60 days of the issuance of the approved Long Term Stewardship (LTS) Plan.

4. An Environmental Covenant, consistent with Delaware 's Uniform Environmental Covenants Act (7 Del.C. Chapter 79, Subchapter II) must be recorded in the Office of the Sussex Recorder of Deeds within 60 days of the issuance of the Long Term Stewardship Plan. The Environmental Covenant must include the following activity and/or use restrictions :

[a.] Limitation of Groundwater Withdrawal. No shallow groundwater wells shall be installed and no groundwater shall be withdrawn from any shallow well on the Property without the prior written approval ofDNREC-SIRS and DNREC Division of Water;

[b.] Compliance with the Long Term Stewardship Plan. All work required by the Long Term Stewardship Plan must be performed to DNREC's satisfaction in accordance with the Plan ; and

[c.] Compliance with Contaminated Materials Management Plan. All work required by the Contaminated Materials Management Plan must be performed to DNREC's satisfaction in accordance with the Plan.

5. A Contaminated Materials Management Plan (CMMP) must be submitted to DNREC within 60 days of the issuance of the Final Plan of Remedial Action. The CMMP will provide guidance to enable construction workers to safely handle any potential groundwater at the Site.

6. The CMMP will be implemented upon its approval by DNREC.

7. A Long-Term Stewardship Plan shall be submitted to DNREC for approval in accordance with the schedule set forth in the approved Remedial Action Work Plan. The LTS plan will detail the groundwater monitoring requirements and schedule to be followed in order to monitor the treatment of the groundwater Contaminants of Concern (COC).

8. The L TS Plan must be implemented within 60 days of its approval by DNREC.

9. A Remedial Action Completion Report must be submitted to DNREC within 60 days of the completion of the remedial actions required in this Proposed Plan.

IO. A request for a Certification of Completion of Remedy (COCR) must be submitted to DNREC within 60 days of approval of the Remedial Action Completion Report.

DNREC proposes the following remedial actions for Operable Unit 2 (OU-2) of the Site, which need to be completed before a Certificate of Completion of Remedy (COCR) can be issued.

I. A Remedial Action Work Plan must be submitted to DNREC for approval within 60 days of the issuance of the Final Plan of Remedial Action.

2. An additional shallow groundwater well must be installed along the southern edge of OU-2 as part of the groundwater monitoring pursuant to the schedule indicated in the DNREC approved Remedial Action Work Plan.

3. A proposed Environmental Covenant must be submitted to DNREC for approval within 60 days of the issuance of the approved Long Term Stewardship (LTS) Plan.

4. An Environmental Covenant, consistent with Delaware' s Uniform Environmental Covenants Act (7 Del.C. Chapter 79, Subchapter II) must be recorded in the Office of the Sussex Recorder of Deeds within 60 days of the issuance of the Long Term Stewardship Plan. The Environmental Covenant must include the following activity and/or use restrictions:

[a.] Use Restriction. Use of Operable Unit 2 (OU-2) of the Property shall be restricted solely to those non-residential type uses

permitted within Commercial, Manufacturing, or Industrial Districts;

[b.] Interference with Remedy. There shall be no digging, drilling, excavating, grading, constmcting, earth moving, or any other land disturbing activities on OU-2 without the prior written approval of DNREC;

[c.] Limitation of Groundwater Withdrawal. No shallow groundwater wells shall be installed and no groundwater shall be withdrawn from any shallow well on the Property without the prior written approval ofDNREC-SIRS and DNREC Division of Water;

[d.] Compliance with the Long Term Stewardship Plan. All work required by the Long Term Stewardship Plan must be performed to DNREC's satisfaction in accordance with the Plan; and

[e.] Compliance with Contaminated Materials Management Plan. All work required by the Contaminated Materials Management Plan must be performed to DNREC's satisfaction in accordance with the Plan.

5. A Contaminated Materials Management Plan (CMMP) must be submitted to DNREC within 60 days of the issuance of the Final Plan of Remedial Action. The CMMP will provide guidance to enable construction workers to safely handle any potential contaminated soil and groundwater at the Site.

6. The CMMP will be implemented upon its approval by DNREC.

7. A Long-Tenn Stewardship Plan shall be submitted to DNREC for approval in accordance with the schedule set forth in the approved Remedial Action Work Plan. The LTS plan will detail: l) the groundwater monitoring requirements and schedule to be followed in order to monitor the attenuation of the groundwater Contaminants of Concern (COC); and 2) the site-inspection schedule to be followed in order to ensure the long-term integrity of the remedy.

8. The LTS Plan must be implemented within 60 days of its approval by DNREC.

9. A Remedial Action Completion Report must be submitted to DNREC within 60 days of the completion of the remedial actions required in this Proposed Plan.

10. A request for a Certification of Completion of Remedy (COCR) must be submitted to DNREC within 60 days of approval of the Remedial Action Completion Report.

What are the long term plans for the Site after the cleanup?

The Brownfield Developer plans to redevelop the Site for mixed residential and commercial use. There will be one of each of the following for the entire Site (OU-1 and OU-2): Remedial Action Work Plan, LTS Plan, CMMP, Environmental Covenant, Remedial Action Completion Report, and COCR. The CMMP will be completed and available for the Site.

How can I find additional information or comment on the Proposed Plan?

The complete file on the Site including the Brownfield Investigation and the various reports are available at the DNREC office, 391 Lukens Drive in New Castle, 19720. Most documents are also found on:

http://www.nav.dnrec.delaware.gov/DEN3/

The 20-day public comment period begins on May 6, 2018 and ends at close of business ( 4 :30 pm) on May 29, 2018. Please send written comments to the DNREC office at 391 Lukens Drive, New Castle, DE 19720 to Kathryn Durant, Project Officer or via email to kathryn.durant@state.de. us.

Figure l : Site Map Figure 2: Site Location Map Figure 3: Operable Unit Map

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FIGURE 1 14028 SUSSEX HIGHWAY

SITE MAP USGS 7.5 MIN TOPO GREENWOOD, DE

FIGURE 2 14028 SUSSEX HIGHWAY

SITE LOCATION MAP 2012 AERIAL

GREENWOOD, DE

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FIGURE 3 14028 SUSSEX HIGHWAY

OPERABLE UNIT MAP 2012 AERIAL

GREENWOOD, DE

Glossary of Terms Used in this Proposed Plan

Brownfield Development Agreement This legal agreement is between a potential developer of a (BDA) Delaware-certified Brownfields Site and the DNREC. The

developer agrees to investigate and cleanup a Brownfields property under the oversight of the Department in exchange for liability protection.

Brownfield Investigation (BFI) Thorough environmental study of a site which includes 1) sampling of site environmental media and/or wastes on the property and 2) conducting a preliminary risk assessment using the data collected to determine the risk posed to human health and the environment.

Certification of Completion of Remedy A formal determination by the Secretary of DNREC that (COCR) remedial activities required by the Final Plan of Remedial

Action have been completed. Contaminated Materials Management A written plan specifying how potentially contaminated Plan material at a Site will be sampled, evaluated, staged,

transported and disposed of properly. Exposure Contact with a substance through inhalation, ingestion, or

direct contact with the skin. Exposure may be short term (acute) or long term (chronic).

Final Plan of Remedial Action DNREC's adopted plan for cleaning up a hazardous site. Risk Likelihood or probability of injury, disease, or death. Restricted Use Commercial or Industrial setting SIRS Site Investigation Restoration Section ofDNREC, which

oversees cleanup of sites that were contaminated as a result of past use, from dry cleaners to chemical companies