1.1.2.1 Location

The Site includes approximately 164 acres located in southeast Newark, generally west of Route 72 (South Chapel Road), between Bellevue Road and Route 4 (East Chestnut Hill Road) in New Castle County, Delaware. 

1.1.2.2 Description of Threat

EPA’s Removal Program will evaluate the potential for vapor intrusion at the Site. Vapor intrusion (VI) is the term used to describe the migration of volatile chemicals from subsurface contaminated soils and groundwater into the indoor air spaces of overlying buildings through openings in the building foundation.  The chemicals may present health risks to residents if they accumulate in buildings.  Common sources of VI include petroleum products, dry cleaning solvents, and other industrial solvents and degreasers including those found at the Site. 

1.1.3 Preliminary Removal Assessment/Removal Site Inspection Results

While EPA is considering the Site for potential inclusion on the NPL, EPA Region 3 management asked the Removal Program evaluate whether VI is a concern at the Site.  The OSC subsequently reviewed available information and environmental sampling data included in DNREC's 2015 Site Investigation (SI) report. 

As part of the SI, 68 groundwater samples were collected from multiple depths at 15 locations.  Permanent monitoring wells were installed at eight of the locations.  PCE was detected in seven of the eight monitoring wells.  During the SI, Delaware’s Division of Public Health Office of Drinking Water sampled three municipal wells and confirmed low levels of groundwater contamination in the untreated/raw groundwater.  The SI summarizes the Preliminary Assessment (PA) that was conducted at the Site by DNREC.  The PA identified multiple areas of potential environmental concern in the area. 

The OSC initiated a removal site evaluation in accordance with Section 300.410 of the National Oil and Hazardous Substances Pollution Contingency Plan (NCP).  As part of the preliminary assessment activities, the OSC conducted several site visits, met with DNREC representatives and EPA site assessment staff.  The OSC also met with the EPA Region 3 vapor intrusion team and the Agency for Toxic Substances and Disease Registry (ATSDR) to review existing groundwater sampling data and discuss the potential for VI occurring at the Site.  

In October 2016, to assist with conducting the removal site evaluation, the OSC issued a work assignment to EPA's Superfund Technical Assessment and Response Team (START) contractor, Weston Solutions, Inc. (Weston). 

In November 2016, the OSC conducted a site visit with a Weston representative.  Later the same day, the OSC attended a public meeting held by DNREC.  DNREC held the meeting to provide information regarding site investigations and to let the community know that Delaware has requested assistance from EPA in addressing the contamination at the Site.    

In January 2017, EPA mailed fact sheets to the surrounding community to let them know about EPA's upcoming activities.

Beginning the week of January 30, 2017, with EPA's oversight, Weston and a drilling subcontractor (Eichelbergers Inc.) installed and developed 9 new groundwater monitoring wells in the Brookside Park and Scottfield residential developments located east of South Chapel Street (Route 72).  With the permission of the Delaware Department of Transportation (DelDOT), the wells were installed in State right-of-ways.  The soil borings from the wells were logged and screened in the field for the presence of volatile organic compounds (VOCs). EPA and DNREC also collected soil samples from the borings which were further screened for VOCs at DNREC's laboratory.  No significant detections of VOCs were found in any of the soil samples.   

On February 14 and 15, 2017, with EPA's oversight, Weston collected water samples from the new monitoring wells.  With the permission of the property owner, EPA and Weston also sampled an existing monitoring well previously installed by DNREC on a commercial property located west of Route 72.  The samples were sent to a lab and analyzed for the presence of VOCs.  Weston also collected water level data from new and existing monitoring wells.    

While homes in these developments do not rely on private drinking water supply wells, the groundwater data was collected to evaluate whether contamination could contribute to vapor intrusion (VI).  

In March, EPA received and reviewed the final validated results of the monitoring well sampling.  All of the wells sampled had either no detections of VOCs or very low concentrations of VOCs that are below EPA vapor intrusion screening levels.  The results of the groundwater sampling indicate that VI is not a concern at this time. 

2.1.2 Response Actions to Date

2.1.3 Enforcement Activities, Identity of Potentially Responsible Parties (PRPs)

2.1.4 Progress Metrics

Given the groundwater sampling results, EPA does not plan to conduct in-home vapor intrusion testing at this time.  To confirm the results and evaluate possible changes in VOC groundwater concentrations, EPA plans to resample the new wells, along with wells previously installed by DNREC in nearby commercial areas, later this year.  EPA will re-evaluate the need for additional investigation, including vapor intrusion testing at that time.   

2.2.1.1 Planned Response Activities

2.2.1.2 Next Steps

EPA will notify area residents of the results of the groundwater sampling. 

The OSC will continue to work with DNREC during the removal site evaluation.   

2.2.2 Issues