Public Comment Period for Proposed Remedy

INTRODUCTION

The U.S. Environmental Protection Agency (EPA) Region 7 invites the public to comment on the Proposed Remedy for the Deeter Foundry Facility in Lincoln, Nebraska. The Proposed Remedy includes institutional controls in the form of site activity and use limitations, a Soil Management Plan, and a Health and Safety Plan to prevent exposures during future excavations on-site.

The public comment period runs from May 8, 2018, through June 6, 2018.

Written comments on the Proposed Remedy must be submitted no later than June 6, 2018, and must be sent to:

The site is surrounded by commercial property on the north, east, southeast, south and southwest, and by open fields or agricultural property to the northeast, west and northwest.

The site has been in operation as a foundry since 1964, and was undeveloped land prior to 1964. As early as June 1987, inspection reports indicate that wastewater including fine sediment was discharged from the cupola furnace scrubber to a former on-site surface impoundment.

A draft Resource Conservation and Recovery Act (RCRA) Facility Assessment (RFA) report, based on the Preliminary Assessment/Visual Site Inspection, was completed in 2002. The RFA report indicated that hazardous baghouse dust, wet scrubber sludge, or similar waste had been disposed of by mixing it with foundry sand and distributing it as fill material around the site.

A limited site screening/investigation conducted in 2011 evaluated the solid waste management units and areas of concern identified in the draft RFA. The intent of the screening/investigation [later referred to as the Phase I RCRA Facility Investigation (RFI)] was to determine whether historical foundry practices had resulted in environmental contamination. The corresponding report identified contamination and recommended more in-depth investigation.

The main part of the RFI was conducted in 2015 and 2016 in the following phases:

• Phase II – April 2015: on-site investigation along the western property boundary
• Phase III – April through November 2016: off-site investigation and sampling to address on-site data gaps from RFI Phases I & II

Data from the RFI were used to develop a conceptual site model that characterized the nature and extent of contaminants in soil and groundwater, evaluated potential exposure pathways, and identified potential receptors.

Interim Remedial Measures conducted in May 2017 included the following:

• Excavation of arsenic- and lead-impacted soils along the western and southern property boundaries
• Placement of limestone along the raised perimeter of the concrete pad along the northern half of the western property boundary to prevent stormwater from potentially eroding under the edges of the concrete pad

SOIL: Ethylbenzene and xylenes were detected in one on-site boring; otherwise, no volatile organic compounds (VOCs) were detected above EPA Regional Screening Levels (RSLs) in soil samples. Metals contamination observed in soils was generally associated with two conditions at the site:

• Fill material directly underlying the concrete slab or at the ground surface, if no concrete was present
• Historic drainage of surficial runoff to localized ditches and swales along the southern and western property boundaries

Lead contamination was observed; however, the elevated concentrations were only found in the shallow soils and decreased with depth into the native soil profile. Cadmium concentrations exceeded EPA residential RSLs, but were below industrial RSLs in three soil samples collected during the 2011 investigation. Additionally, while some arsenic concentrations were detected at levels exceeding industrial RSLs, they were relatively close to published background levels. Off-site soil samples collected west of the site, in the area of the soccer field, showed no metals concentrations exceeding EPA residential soil RSLs, except naturally-occurring arsenic.

GROUNDWATER: Federal Maximum Contaminant Levels (MCLs) are standards that are set by EPA for drinking water quality. An MCL is the legal threshold limit on the amount of a substance that is allowed in public water systems under the Safe Drinking Water Act.

Groundwater sampling and analysis detected chlorinated VOCs at concentrations exceeding MCLs at the site, as well as off-site to the west. However, the investigation concluded this contamination was not caused by Deeter’s operations. A follow-up investigation for that contamination is being overseen by the Nebraska Department of Environmental Quality.

Other groundwater VOC contamination was detected on-site, but only in a localized area. Arsenic was detected in groundwater at concentrations exceeding its respective MCL at one location on the site, but is also expected to be limited to a localized area.

CLEANUP GOALS

Cleanup levels for individual chemicals of concern in soil are the November 2017 EPA RSLs for industrial soil. Each cleanup goal is based on no greater than a one-in-a-million chance of cancer, and is also protective of non-cancer health effects. Activity and use limitations, and a Soil Management Plan and Health and Safety Plan, are under development to eliminate or reduce exposure to any residual contamination at concentrations above these cleanup goals. Cleanup levels for individual contaminants of concern in groundwater are EPA’s MCLs or, if MCLs are unavailable for a given contaminant, the November 2017 EPA RSLs for tap water.

CONTAMINANT RISKS

The Deeter Foundry did not conduct a site-specific risk assessment for the site. However, there is a potential for unacceptable non-cancer risk, based on a streamlined risk screening using default exposure factors for a hypothetical construction worker exposed to subsurface soils below the existing concrete or gravel cover on-site.

PROPOSED REMEDY

The Proposed Remedy entails implementation of institutional controls consisting of activity and use limitations for the site. These limitations will ensure that future land use remains industrial only, and will limit access to groundwater to prevent exposure to any contaminants of concern. No groundwater monitoring will be required.

The Proposed Remedy also includes the implementation of an on-site Soil Management Plan (SMP) to protect potential receptors from direct contact with contaminated soils or groundwater. The SMP will prescribe the required procedures for the identification, handling, transportation, and disposal of potentially-contaminated media (soil and groundwater) at the site that may be encountered during any excavation or subsurface activities.

FOR MORE INFORMATION

EPA encourages the public to review the Administrative Record and comment on the Proposed Remedy.

Comments or requests for information must be submitted prior to the expiration of the public comment period, which ends June 6, 2018.

• Explain your views.
• Tell us if you support or disagree with the Proposed Remedy. Please be specific.
• Provide potential alternatives to the Proposed Remedy.

The Administrative Record is available during normal business hours at the following locations:

EPA Region 7 Records Center
11201 Renner Boulevard
Lenexa, KS 66219
Toll-free: 1-800-223-0425

Requests for a public availability session must be made in writing to the EPA contact at the address listed above, and must state the nature of issues to be raised. EPA will evaluate any requests and hold an availability session if it finds that it will contribute to the decision-making process by clarifying significant issues affecting the Proposed Remedy.

EPA will make a Final Decision on the Proposed Remedy only after the public comment period ends and all comments are reviewed. EPA may modify the Proposed Remedy based on any new information and comments from the public.

Individuals may write to EPA contacts below to join the mailing list. Joining the mailing list will allow an individual to receive any updated information directly throughout the remedy selection process.

If you have questions or want to receive further information, please contact: