The Neal's Radiator Site (the Site) is located in a residential neighborhood. Buildings on the property include a single family house, a well house, a free-standing enclosed garage, and a shop building. Property boundaries are marked by US-21 to the northwest, a fence to the northeast, and the near edge of gravel roads to the southeast and southwest. The property is bordered to the northeast, southeast, and southwest by single-family residences. Ebenezer Elementary School is located on a hill on the other side of Turnersburg Highway (US-21) to the northwest. Storm water flow on the property is from the north to the south; storm water from the shop area appears to flow south across Ray Lane to an unused pasture and a small stream approximately 200 feet down gradient of the shop. Mr. Neal’s residence is on a private water supply well system. Property owners immediately adjacent are on county water supply. The Site is contaminated with high concentrations of lead, arsenic, iron, chromium, antimony and vanadium from Mr. Neal’s radiator repair business dating back to 1968-69 time-frame.
Mr. Neal purchased the property in 1954 and began a radiator repair business in 1968-69. The repair process involved cleaning (metal) radiators in a caustic dip tank heated to 180 degrees Fahrenheit, rinsing the radiators in a large metal basin, and then placing the radiator in the leak test tank to identify leaks. The caustic rinse water from the metal basin was then collected in a sump and pumped into a 250-gallon above ground storage tank (AST) outside the main shop building. According to Mr. Neal, he removed the radiators on-site and stopped repairing radiators in the shop in July 2004 after a NCDENR investigation. Currently, the shop is used by Mr. Neal’s sons to perform contract metal work.
1. Removal Site Evaluation
NCDENR Division of Waste Management staff performed a compliance inspection of the shop facility on June 24, 2004. Several waste areas and spills were identified during the inspection including:
Rinse water from the caustic bath. Mr. Neal apparently used the rinse water to water outdoor plants and vegetables around his home. Evidence of spills or leaks under the 250-gallon waste tank was observed during the compliance inspection.
Caustic dip tank sludge stored in containers inside the shop.
A pile of radiators near the front of the shop that was deemed a concern for heavy metal soil contamination.
As a result of their investigation, NCDENR staff conducted environmental sampling at the site on July 7, 2004. Elevated total lead concentrations were reported in soils near the shop (921-2600 mg/kg) and near the 250-gallon waste tank (26,558-133,002 mg/kg). Based on this information, NCDENR referred the site to the U.S. EPA Emergency Response and Removal Branch for further review and action.
On December 4, 2004, EPA OSC Barbara Scott and START-2 conducted a site reconnaissance at Neal’s Radiator Service. Subsequently, on December 20, 2004, START-2 along with OSC Scott conducted a removal assessment sampling event. NCDENR staff were also present during this event and helped conduct on-site screening of the surface soils at sampling locations for lead using a portable x-ray fluorescence spectrometer (XRF). On-site XRF measurements were made of soil from locations previously sampled by NCDENR and were approximately within 20% of the reported analytical results from these locations. A total of eight (8) surface soil samples were collected from the site, four from the front of the property and three from the back. A background sample was also collected. A total of six (6) subsurface samples were collected from the site; two from the front, three from the back and one background. As well, one (1) sediment sample was collected down gradient of the shop building from a small stream on the adjacent property to the south of the site. A total of four (4) waste samples were collected for waste characterization. These waste samples were collected from the leak test tank, the caustic dip tank, the 250-gallon waste tank and solid waste from the sludge removed from the caustic dip tank.
The surface soil, subsurface soil, and sediment samples were analyzed by the Contract Laboratory Program (CLP) for total Target Analyte List (TAL) metals. These samples were then compared to the October 2004 version of the EPA Region 9 Preliminary Remediation Goals (PRGs) for residential soil exposure. Surface and subsurface soil samples were also analyzed for pH by Pace Analytical Services (Pace) to determine potential metal solubility and mobility on the site. Waste samples were analyzed by Pace for Toxic Characteristic Leachate Procedure (TCLP) analyses for waste characterization purposes.
In summary, surface soils, iron and arsenic were detected at concentrations exceeding PRGs in all samples. Antimony, total chromium, lead, vanadium were detected at concentrations exceeding PRGs in one or more samples. In subsurface soils, iron and arsenic were detected at concentrations exceeding PRGs in all samples collected. In the sediment sample, arsenic exceeded its PRG. Based on these sample results, surface soils less than 12 inches below ground surface contain lead at concentrations exceeding the PRG of 400 mg/kg in the front and back of the shop.
In the RAT Notification and Priority Recommendation Memorandum from OSC Barbara Scott to Matt Taylor, Chief, Removal Operations Section, dated April 11, 2005, OSC Scott recommended a high priority for the Site.
As a result of the results of the site assessment and the RAT, OSC Williamson mobed with ERRS and START contractors to the site on January 10, 2007 and began removal of lead-contaminated soil. The removal action was concluded on February 7, 2007.
