FINAL PLAN OF REMEDIAL ACTION

HESSLER PROPERTY SITE (OPERABLE UNIT 1)

401 Garasches Lane Wilmington, Delaware

March 2018 DNREC Project No. DE-1203

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 Hessler Property Operable Unit 1 Site.

DNREC issued public notice of the Proposed Plan of Remedial Action (Proposed Plan) for the Site on February 12, 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

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othy T. Ratsep, Progra Administrator Site Investigation and Restoration Section

Date

PROPOSED PLAN OF REMEDIAL ACTION

Hessler Property Site Operable Unit 1

Wilmington, Delaware DNREC Project No. DE-1203

February 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: 1 - 4

• Glossary of Terms

PROPOSED PLAN OF REMEDIAL ACTION

Approval:

Hessler Property Site Operable Unit- I

Wilmington, Delaware DNREC Project No. DE-1203

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

Approved by:

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PROPOSED PLAN Questions &Answers Hessler Property Site

Operable Unit-1

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 Hessler Property Site, Operable U nit-1?

The entire Hessler Property site investigation area consists of two tax parcels (26-057.00-011 and 26-057.00-005) totaling approximately 8.5-acres along the eastern edge of South Walnut Street, north of Garasches Lane, and south of Diamond Chemical & Supply Co. in Wilmington, Delaware (Figure 2). The property is zoned 26M-1 Light Manufacturing. The addresses for the parcels are 401 Garasches Lane and 610 South Market Street.

For the purposes of this Proposed Plan, the Site will be administratively divided into two (2) Operable Units. This Proposed Plan will address the environmental concerns and proposed cleanup activities for Operable Unit-1 (OU-1). A separate Proposed Plan for OU-2 will be developed and advertised for public comment in the future. OU-1 consists of a portion of tax parcel 26-057.00-01, a portion of tax parcel 26-057.00-005, the ditch portion of tax parcel 26-050.00-031, and certain right of way areas shown in Figure 3. The right of way areas included in OU-1 were previously included in the site investigation and Final Plan of Remedial Action for the Christina River Bridge Site (DE-0334) and are included in this Proposed Plan of Remedial Action for development purposes. OU-1 is approximately 6.5 acres and an exact acreage will be determined by a future survey.

The property is currently owned by the Riverfront Development Corporation. The property is vacant and is heavily vegetated with trees and shrubs. The property has historically been undeveloped dating back to the early 1900s.

What happened at the Hessler Property Site, Operable U nit-1?

Historical research indicates the Site was maintained as undeveloped marsh land and surrounded by commercial and industrial properties. Test pits and soil borings indicate the Site was heavily filled with construction waste and other debris (brick fragments, concrete, ash, wood, rubber, porcelain, and glass etc.) over a majority of the property to a depth of approximately 15 feet bgs. Amosite asbestos material was positively identified in one test pit location. Most recently the site was utilized as a lay-down and storage area for steel products.

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What is the environmental problem at the Hessler Property Site, Operable Unit-1?

Soil samples collected during a DNREC Brownfield Preliminary Assessment (BPA) conducted on September 6 and 7, 2000 indicated elevated levels of inorganic contaminants including arsenic, antimony, chromium VI, cobalt, copper, barium, manganese, cadmium, zinc, vanadium, and lead in addition to various P AHs. Groundwater water samples collected on October 3, 2000 indicated levels of total and dissolved arsenic and iron and petroleum-related TI Cs. Drums, 5-gallon buckets, coal, ash, slag, wood, wire, etc. was encountered during previous field activities.

A Brownfield Investigation was conducted in winter 2014 - spring 2015, a Supplemental Investigation was completed in spring 2015 and a Focused Feasibility Study was prepared in the summer 2015.

Metals (antimony, arsenic, total chromium, chromium VI, copper, iron, lead, and zinc), PAHs, and Total PCBs again were detected in the surface soil above DNREC's January 2015 screening levels in the soil samples analyzed according to HSCA protocols.

Metals (aluminum, antimony, arsenic, barium, cadmium, total chromium, chromium VI, cobalt, copper, lead, mercury, nickel, silver, and zinc), P AHs, and Total PCBs were again detected in the subsurface soil above DNREC's January 2015 screening levels in the soil samples analyzed according to HSCA protocols.

Due to the high concentrations of lead in the soil, 8 soil samples were analyzed at TestAmerica for TCLP lead to evaluate if the soil would be characterized as hazardous as defined by the EPA. TCLP lead was detected above RCRA hazardous waste criteria in two of the eight samples.

Metals (arsenic, barium, chromium, iron, lead, and manganese) were detected in the Site dissolved groundwater above DNREC's January 2015 screening levels. SVOCs (benzo[a]pyrene and benzo[b ]fluoranthene) and VOCs (TCE and vinyl chloride) were detected in one groundwater sample (HP-MW06-W001) at concentrations that exceed their respective DNREC's January 2015 screening levels.

Based on groundwater elevations measured in the Site's monitoring wells, the majority of the groundwater on the Site appears to flow east, toward the standing water body located along the eastern property boundary of the property. Metals (antimony, arsenic, cadmium, total chromium, copper, iron, lead, manganese, mercury, nickel, silver, and zinc,), cyanide, and PAHs were detected in the sediment sample collected from the ditch along the eastern edge of the Site above DNREC's January 2015 screening levels analyzed according to HSCA protocols. A human health risk assessment determined that potential unacceptable risk exists via direct contact with the contaminated sediments in the ditch along the eastern edge of the Site.

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What clean-up actions have been taken at the Hessler Property Site, Operable Unit-1?

No remedial actions, other than the 2000 and 2014/15 investigations, have occurred at the Site to date.

What is planned for the Hessler Property Site, Operable Unit-1?

The current redevelopment plan for the Hessler Property Site, OU-1 is a 140,000-square-foot, multi-purpose sports complex housing indoor basketball courts, and indoor and outdoor soccer fields, along with associated roadways and parking lots.

What additional clean-up actions are needed at the Hessler Property Site, Operable Unit-1?

DNREC proposes the following remedial actions for the Site, which needs to be completed before a Certificate of Completion of Remedy (COCR) can be issued:

DNREC proposes the following remedial actions for the Site, which needs to be completed before a Certificate of Completion of Remedy (COCR) can be issued:

1. Placement of an impervious cap across the Site to prevent storm water infiltration through the impacted subsurface soils. The impervious cap will reduce contaminant migration of impacted groundwater to the ditch along the eastern property boundary;

2. Implementation of a long-term groundwater monitoring program to assess the effectiveness of the impervious cap. In the event that the impervious cap does not sufficiently reduce metal and/or organic contaminant levels in groundwater below acceptable DNREC levels, implementation of an alternative remedy such as a Apatite II, Organoclay, zero-valent iron or other DNREC-Approved permeable reactive barrier will be required to be implemented. A pre-determined location sufficient for the construction of such alternate remedy along the eastern property boundary has been identified and will be reserved from development in the event the alternate remedy is required (Figure 4 );

3. Construction of a cap consisting ofhardscaping, such as a culvert or concrete liner, for the ditch portion of the Site that will prevent human contact to contaminated sediment, but not impede the drainage way of the existing ditch.

4. Record an Environmental Covenant, consistent with Delaware's Uniform Environmental Covenants Act (Title 7, Del. Code Chapter 79, Subtitle II) (UECA), in the office of the Recorder of Deeds within 60 days of DNREC approving the Long Term Stewardship Plan. The Environmental Covenant will include the following:

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[a.] Use Restriction. Use 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, constructing, earth moving, or any other land disturbing activities [at depths greater than 2 feet] on the Property [including any repair, renovation or demolition of the existing structures on the on the Property]without the prior written approval of DNREC-SIRS;]

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

[d.] Compliance with Long Term Stewardship Plan. Perform all work required by the Long Term Stewardship Plan ("L TS Plan"), as issued, approved, modified or amended by DNREC;]

5. All redevelopment work will be performed in accordance with a DNREC-approved Remedial Action Work Plan (RA WP), Contaminated Materials and Water Management Work Plan (CMMP), and the Site Specific Health and Safety Plan, and implement the CMMP upon DNREC approval;

The following timetable shall apply to the remedial actions listed above:

6. Submit a Remedial Action Work Plan for DNREC's approval within 60 days after the issuance of the Final Plan of Remedial Action.

7. Submit to DNREC a CMMP within 60 days of the issuance of a Final Plan of Remedial Action. The CMMP will allow construction workers to safely handle any potential contaminated soil and groundwater at the Site.

8. Submit a Long-Term Stewardship (LTS) Plan as per the schedule set in the DNREC approved Remedial Action Work Plan. The L TS plan will detail: 1) the groundwater monitoring requirements and schedule to be followed in order to monitor the attenuation of the groundwater COCs, and 2) the site-inspection schedule to be followed in order to ensure the long-term integrity of the remedy.

9. Implement the L TS Plan within 60 days upon DNREC approval.

10. Submit Remedial Action Completion Report to DNREC within 60 days of the completion of the remedial actions required in this Proposed Plan.

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11. Request a COCR within 60 days ofDNREC'S approval of the Remedial Action Completion Report.

What are the long term plans for the Hessler Site, Operable Unit-1 after the cleanup?

The Site is planned to be used as a basketball arena and indoor and outdoor soccer fields, along with associated roadways and parking lots. DNREC plans to issue a Certification of Completion of Remedy for the site after the completion of clean-up, and the redevelopment of the property.

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

The complete file on the Site including the Brownfield Investigation Report, Supplemental Investigation Summary, Focused Feasibility Report and the various other documents 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 February 12, 2018 and ends at close of business (4:30 pm) on March 5, 2018. Please send written comments to the DNREC office at 391 Lukens Drive, New Castle, DE 19720 to Kristen Thornton, Project Officer or Paul Will, Program Manager or via email to Kristen.Thomton@state.de.us or Paul.Will@state.de.us .

Figure 1: Site Location Figure 2: Site Location with Boundary Figure 3: Operable Units Figure 4: Proposed Location of Remedy On-Site

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Figure 1

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Brightfields, Environmental Evalua t ion

Investigation, and Remediation

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Figure 2

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Wilmington, Delawa re 19601 302-656-9700 fa x

Site Layout and Surrounding Land Use Hessler Property (DE-1169)

Wi imington . Delaware

125 250 ----===~Feet

Figure 3

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BrightFields, Inc. Environmental Evaluation

Investigation. and Remediation

312-656-9600 312-656-9700 fax

Option 1 OU Layout - Hessler Property Hessler Property (DE-1169)

'Mlm1ngton. Delaware

2n12010 Fig. No 0992 .34 .52 Figure 1

75 150 ----===:Jfeet

D Surveyed Property Boundary

• Available Well Location Area Source: DEMAC -Aerial 2012;

Tax Parcels Delaware DataMIL - Tax Parcels; Site Plan provided by BPGS.

Environmental Evaluation Investigat ion , and Remediation

801 Industrial Street 302-656-9600 Wilmington, Delaware 19801 302-656-9700 fax

Available Well Location Areat - Hessler Property Hessler Property (DE-1203)

Wilmington , Delaware

0 75 150

•••-===:::::::i Feet

File Name:

Fig 1 AvailWell. mxd

Glossary of Terms Used in this Proposed Plan

Area of Concern (AOC) A discrete section of the Site representing the local Bounds of contamination in soil or ground water.

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.

Certified Brownfield A Brownfield that DNREC has determined is eligible for partial funding through the Delaware Brownfields Program

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. Contaminant of Concern (COC) Potentially harmful substances at concentrations above

Acceptable levels. 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. Groundwater Management Zone A geographical area where DNREC restricts drilling for

ground water because it is contaminated Hazardous Substance Cleanup Act Delaware Code Title 7, Chapter 91. The law that enables (HSCA) DNREC to identify parties responsible for hazardous

substances releases and requires cleanup with oversight of the Department.

Human Health Risk Assessment An assessment done to characterize the potential human (HHRA) Health risk associated with exposure* to site related

chemicals. Poly chlorinated biphenyls (PCBs) A synthetic, carcinogenic chemical formerly used in a wide

Variety of industrial applications but banned from most uses by the US EPA in 1979.

Preliminary Risk Assessment A quantitative evaluation of only the most obvious and likely risks at a site

Risk Likelihood or probability of injury, disease, or death. Risk Assessment Guidance for An EPA guidance document for superfund sites Superfund (RAGS) Restricted Use Commercial or Industrial setting Site Inspection (SI) Environmental study of a site which includes the sampling

of soils, groundwater, surface water, sediment and/or

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wastes on the property, as appropriate. This evaluation is performed on behalf of the United States Environmental Protection Agency (U.S. EPA).

SIRS Site Investigation Restoration Section of DNREC, which oversees cleanup of sites that were contaminated as a result of past use, from dry cleaners to chemical companies

Toxic Substance Cleanup Act (TSCA) The federal statute requiring and regulating the cleanup of PCBs.

Uniform Risk-Based Remediation A set of concentration criteria for various contaminants Standards (URS) potentially present in site media that are developed for

protection of human health and the environment US EPA United States Environmental Protection Agency

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