FINAL PLAN OF REMEDIAL ACTION

FORMER WILMINGTON PIECE DYE OPERABLE UNIT 2

0 Riddle Avenue Wilmington, Delaware

June 2017 DNREC Project No. DE-1304

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 Former Wilmington Piece Dye OU-2 Site.

DNREC issued public notice of the Proposed Plan of Remedial Action (Proposed Plan) for the Former Wilmington Piece Dye OU-2 Site 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.

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DE-1304 II 89

DNREC-Site Investigation and Restoration Section (DNREC-SIRS)

LEGAL NOTICE

FINAL PLAN OF REMEDIAL ACTION FOR THE FORMER WILMINGTON PIECE DYE SITE OU-2 (DE-1304)

The Department has adopted a plan regarding the clean-up of Operable Unit 2 of the Former Wilmington Piece Dye Site located in Wilmington. The Site, once used as a textile mill from the 1830’s to early 2000’s required the removal of contaminated soil, the creation and adherence of a Contaminated Materials Management Plan, and restrictions of groundwater withdraw. DNREC issued public notice of the Proposed Plan for Operable Unit 2 of the Former Wilmington Piece Dye Site on June 4, 2017. There were no comments or questions from the public regarding the Proposed Plan. Details of the Final Plan, at the office of DNREC-SIRS (391 Lukens Drive, New Castle, DE, 19720) or online at:

http://www.dnrec.delaware.gov/whs/awm/SIRB/Pages/SIRBPlans.aspx

The public may appeal this Final Plan for a period of, twenty (20) days from the date of this notice. In the event the twentieth day falls on a weekend or holiday the final date to appeal will be the next business day. For additional information, please contact Patrick Boettcher, Project Manager at (302) 395-2600 or email Patrick at Patrick.Boetttcher@state.de.us.

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DE-1304 II B9

THIRD AMENDED PROPOSED PLAN OF REMEDIAL ACTION

Former Wilmington Piece Dye OU-2

Wilmington, Delaware DNREC Project No. DE-1304

JUNE 2017

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, 2, 3, & 4 • Glossary of Terms

THIRD AMENDED PROPOSED PLAN OF REMEDIAL ACTION

Approval:

Former Wilmington Piece Dye Operable Unit 2 (Upper Parcel)

Wilmington, Delaware DNREC Project No. DE-1304

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

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PROPOSED PLAN Questions & Answers

Former Wilmington Piece Dye

Site, OU-2

What is the Third Amended 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. When new information regarding the release of contamination is identified at a Site after the Proposed Plan or Final Plan has been issued, an Amended Proposed Plan must be issued to once again solicit public comment. DNREC uses a comprehensive assessment process, which includes the additional data, to develop the new proposal for remedial action at the Site. What is the Former Wilmington Piece Dye Site, OU-2? The entirety of the Former Wilmington Piece Dye Site currently occupies four tax parcels within New Castle County, Wilmington, Delaware. Three tax parcels are contiguous and one parcel is located approximately 900 feet west of the others. Figure 1 depicts the entire land mass that constitutes the Former Wilmington Piece Dye Site. Tax Parcels 260062041, 2600620045, and 260023009 are located on the Brandywine River and have historically been referred to as Operable Unit 1 (OU-1). For the purpose of the December 2016 Amended Remedial Investigation, the May 2017 Amended Remedial Investigation Report for OU-2 and this Third Amended Proposed Plan of Remedial Action, contiguous parcels 260062041 and 2600620045 will be considered OU-1, or informally as the Lower Parcel. Historically, OU-2 was considered tax parcel 2600620046 (Figure 2). It will remain as OU-2 and informally as the Upper Parcel. This PPRA only addresses OU-2. The standalone parcel, New Castle County parcel 260023009, is now considered OU-3. This PPRA does not address OU-3, nor does it address OU-1. This PPRA only addresses OU-2. OU-2 is located at 0 Riddle Avenue and is bounded to the north and east by the OU-1 of the Former Wilmington Piece Dye Site and residential properties to the south and west. OU-2 includes approximately 6.27 acres. OU-2 formerly housed five (5) Aboveground Storage Tanks (ASTs) which stored fuel oil used for operations on OU-1. OU-2 also formerly housed one building that was used to store dry goods. The remedial investigation only focused on soil on the Site and this PPRA only addresses soil on OU-2.

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The Former Wilmington Piece Dye Site has also been known as the Bancroft Mill-Pre Remedial Site as wells as Bancroft Mills Site with alternative Site numbers of DE-1101 and DE-1130, respectively. What happened at the Former Wilmington Piece Dye Site, OU-2? Up until 2003, the Site has been in continuous operation since the early 1800’s. Historical businesses that operated on the lower parcel, OU-1, at the Site reportedly centered on the manufacture and dying of woolen and cotton fabrics as well as bleaching and waterproofing of fabrics. OU-2 housed several petroleum Aboveground Storage Tanks (ASTs) used to either fuel the boiler plant or equipment located on the lower parcel. The ASTs formerly located on OU-2 are registered with the DNREC-Tank Management Section (DNREC-TMS) under Facility identification number 7-000519. What is the environmental problem at the Former Wilmington Piece Dye Site, OU-2? In 1997, the DNREC-SIRS conducted a Brownfield Preliminary Assessment II of the upper and lower parcels of the site (Currently considered OU-1 and OU-2). Results of the BPA II indicated that a comprehensive Remedial Investigation (RI) was required. An RI was completed, with the final Report issued, in May 1999 and a Final Plan of Remedial Action was issued in April 2000. In 2004, the property was sold with the intention of changing the use of the site from nonresidential to residential. The commercial restriction required in the April 2000 Final Plan was removed and further investigation was required in the Second Revision to the Final Plan dated May 2005. In June 2006, a release from two ASTs, one 282,000-gallon and one 110,000-gallon number 6 fuel oil, formerly located on OU-2 was discovered at the boiler house on OU-1. The release was managed in emergency response actions. The 282,000-gallon and 110,000-gallon number 6 fuel oil ASTs were emptied and investigated in July 2007, resulting in the issuance of a Conditional No Further Action Letter from the DNREC-TMS. Between September 2016 and March 2017, several phases of a Remedial Investigation have been conducted to adequately characterize OU-2. Soil samples were collected from areas with recognized environmental conditions, including ASTs, electrical transformers, and drum storage areas. In addition, soil samples were collected beneath the road way and from multiple areas that will be developed. The investigative activities of 2016 and 2017 generated the information needed to amend the 1999 Remedial Investigation and evaluate OU-2 for future residential use. The May 2017 Amended RI report for OU-2, which combined the historic data sets generated by DNREC and RMT and the new data set generated by WESTON presented risk calculations that were performed for residential direct exposure to contaminants of concern (COCs) in soil within the OU-2. The COCs evaluated in either surface soils or deep soils were: benzo[a]anthracene,

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benzo[a]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, dibenzo(ah)anthracene, indeno[1,2,3-cd]pyrene, arsenic, copper, and lead. Residential risk from soil was evaluated under three different exposure scenarios. The first exposure scenario was residential exposure to surface soil as the property sits today. The cumulative carcinogenic risk estimates to current surface soil is 6E-06 and a child non-cancer hazard index of 0.04. Due to the topographic variations of OU-2, soil grading will have to be conducted to make room for future development. Because of the anticipated grading activities, residential exposure to total combined soil was evaluated. Total combined soil assumes a mix of shallow surface soil and deeper soil. The cumulative carcinogenic risk estimates to total combined soil is 1E-05 and a child non-cancer hazard index of 0.07. Lastly, residential exposure to only deep soil was also considered. This is a highly unlikely scenario once a community is developed, but has a slim potential during development activities. The cumulative residential carcinogenic risk estimates to deep soil is 4E-05 and a child hazard index of 0.2. In each scenario non-carcinogen child risk is below DNREC-SIRS acceptable risk standard of 1. Carcinogenic risk to current surface soil is below the DNREC-SIRS acceptable risk standard, while residential carcinogenic risk to total combined soil meets the DNREC-SIRS acceptable risk standard of 1E-05. Residential carcinogenic risk to only deep soil exceeds an acceptable risk. Soil exposure to future excavation workers does not exceed an acceptable risk in any scenario. Residential exposure to groundwater was not evaluated during the Remedial Investigation. What clean-up actions have been taken at the Former Wilmington Piece Dye Site, OU-2? After reviewing analytical results from samples collected from around the former ASTs, Weston conducted soil removal activities around sample RFUP-P-2, a sample associated with piping from AST #1 (Figure 3), and around AST #4 and #5 and the pump house (Figure 4). Elevated concentrations of Polynuclear Aromatic Hydrocarbons (PAHs) were detected in each location. Approximately one cubic yard of contaminated soil was removed from around RFUP-P-2 in October 2016. Confirmation sample collected following the excavation indicated that the extent of the release was removed. Approximately 180 yards of contaminated soil was removed from the area of ASTs #4 and #5 in October 2016. Confirmation samples indicated that high levels of PAHs remained in the soils. An additional 140 yards of contaminated soil was removed from the area in November 2016. Confirmation sample indicated that high levels of PAHs remained at the northern extent of the excavation. Weston submitted a Sampling and Analysis plan for additional delineation and soil removal on March 10, 2017 to DNREC-SIRS. The SAP called for pre-delineation of the extent of the contamination and removal up until a point deemed acceptable. In April 2017 additional contaminated soil was removed. On April 27, 2017 lead impacted soil was removed from test pit locations TP-9 and TP-11 (Figure 3). Samples collected from a depth of six to eight feet below grade reported

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concentrations of lead at 2,590 mg/kg and 635 mg/kg in sample locations TP-9 and TP-11, respectively. Delineation samples were collected but were not reported in the Remedial Investigation Report. What does the owner want to do at the Former Wilmington Piece Dye Site, OU-2? The Site will be redeveloped for residential use as a townhome community. What additional clean-up actions are needed at the Former Wilmington Piece Dye Site, OU-2? DNREC proposes the following remedial actions for the Site, which need to be completed before a Certificate of Completion of Remedy (COCR) can be issued.

1. 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. Soil removed from basement excavations and excavations below two feet must be incorporated as deeper onsite fill in accordance with the Remedial Action Work Plan and the CMMP.

3. A proposed Environmental Covenant must be submitted to DNREC for approval within 60 days of the issuance of the Final Plan of Remedial Action.

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 New Castle County Recorder of Deeds within 120 days of the issuance of the Final Plan of Remedial Action. The Environmental Covenant must include the following activity and/or use restrictions:

[a.] 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;

[b.] 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 30 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.

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

7. 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.

8. A completion report for the interim remedial action to removed lead hot spots from soil sample locations TP-9 and TP-11 must be submitted within fifteen (15) days of the issuance of a Final Plan of Remedial Action. Interim remedial action will only be considered successful if confirmation samples are under 400 mg/kg.

9. Lead reported in historic surface sample location TP-2s was not addressed during the April 2017 interim remedial action despite having a reported concentration of lead over 1,000 mg/kg. A confirmation sample must be collected from the location of TP-2s and if lead is identified over 1,000 mg/kg soil delineation and removal must occur.

What are the long term plans for the Site after the cleanup? The Site will be developed for residential use. How can I find additional information or comment on the Proposed Plan? The complete file on the Site including the Remedial 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 June 4, 2017 and ends at close of business (4:30 pm) on June 26, 2017. Please send written comments to the DNREC office at 391 Lukens Drive, New Castle, DE 19720 to Patrick Boettcher, Project Officer or via email to Patrick.Boettcher@state.de.us.

Figure 1: Tax Parcel Map of OU-1, OU-2, and OU-3 Figure 2: OU-2 Figure 3: OU-2 Sampling Plan

Figure 4: Interim Action Around AST #4 and #5 PRB:mm PRB17043.doc; DE-1304 II B8

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Glossary of Terms Used in this Proposed Plan

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 (COCR)

A formal determination by the Secretary of DNREC that 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 Plan

A written plan specifying how potentially contaminated 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. Hazardous Substance Cleanup Act (HSCA)

Delaware Code Title 7, Chapter 91. The law that enables DNREC to identify parties responsible for hazardous substances releases and requires cleanup with oversight of the Department.

Human Health Risk Assessment (HHRA)

An assessment done to characterize the potential human 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 Superfund (RAGS)

An EPA guidance document for superfund sites

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 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

US EPA

United States Environmental Protection Agency