Sampling Results in Eastern Heights, Grenada, MS

Overview

In June 2015, EPA directed the Grenada Manufacturing, LLC, facility (Facility, commonly known as Grenada Stamping and currently operated by Ice Industries) to conduct environmental sampling in and around the Eastern Heights neighborhood. EPA oversaw investigations in September 2015 and March 2016, which included two rounds of indoor and outdoor air sampling and one round of groundwater and soil sampling in the Eastern Heights neighborhood.

Since then, EPA has performed its own sampling for contaminants in indoor and outdoor air, groundwater, surface water and soil in the Eastern Heights neighborhood, at the Facility property and surrounding areas.

All sampling from the Eastern Heights neighborhood results are posted as they become available below. Based on results received to date, EPA has determined that there is no immediate threat to public health in the Eastern Heights neighborhood due to trichloroethene (TCE).

EPA has also directed the Facility to conduct environmental sampling inside the manufacturing building.

Facility sampling results are posted as they become available.

EPA will use the results of all the sampling events to inform the ongoing Resource Conservation and Recovery Act (RCRA) cleanup of the contamination from the Facility.

Results Summary

Residential Indoor Air and Sub-Slab Air

Sampling is being performed in homes to evaluate whether TCE may be entering structures in the form of vapor from contamination below ground (also referred to as “vapor intrusion”).

Six homes have been tested twice, in September 2015 and March 2016 by the Facility’s contractor with EPA oversight. During the September 2015 sampling event, TCE was detected above screening levels in the indoor air of some of the homes, but below levels that require a response action. TCE was not detected in any of the indoor air samples during the March 2016 sampling event. TCE was not detected in the sub-slab air (the air beneath the foundation slab) in samples collected during September 2015 and March 2016. These results indicate that TCE is not likely entering the homes from a below-ground source, such as groundwater. (See sampling report dated June 1, 2016.)

In May 2016, EPA tested another 17 homes in the south and southeast area of the neighborhood closest to the area of groundwater contamination (based on additional groundwater data collected when the original six homes were tested). EPA also used its mobile laboratory, the Trace Atmospheric Gas Analyzer (or TAGA bus), to screen the air inside of each home and conduct real-time analyses to assist the sampling team with making field decisions. TCE was not detected in any indoor air samples. Sub-slab air was also monitored, and TCE was detected below screening levels in two homes. The results indicate that TCE is not likely entering the homes from a below-ground source, such as groundwater. (See sampling report dated August 19, 2016.)

In November/December 2016, EPA conducted a second round of vapor intrusion testing in the same 17 homes. TCE was detected in the indoor air of one residence at a level below the screening level. TCE was also detected in sub-slab air in two homes at levels far below the screening level. Consistent with previous results, EPA did not find that chemicals present in the groundwater were entering homes via vapor intrusion. (See sampling report dated March 17, 2017.)

Residential Outdoor Air

Outdoor air sampling results have been varied. In the fall of 2015, TCE was detected above screening levels but below levels that require a response action near six residences in Eastern Heights where indoor air sampling was performed. (See sampling report dated June 1, 2016.)

In January 2016, EPA tested outdoor air from five locations in Eastern Heights and TCE was not detected in any of the samples. (See sampling report dated April 5, 2016.)

In May 2016, EPA collected outdoor air samples from four air monitoring stations in Eastern Heights during 24-hour periods over three days. TCE was detected in 1 of the 15 samples at a level below the screening level. (See sampling report dated August 19, 2016.)

EPA’s mobile laboratory, the TAGA bus, also monitored outdoor air throughout the Eastern Heights neighborhood, at the Facility and in nearby areas. The TAGA bus did not detect any TCE or TCE-related chemicals in outdoor air in Eastern Heights. At the Facility, EPA detected low levels of TCE and TCE-related chemicals in the outdoor air near the plant building and a drainage ditch. (See sampling report dated August 1, 2016.)

In September 2016, EPA tested outdoor air from five locations in Eastern Heights and TCE was detected in all samples. TCE was detected above screening levels but below levels that require a response action. (See sampling report dated December 20, 2016.)

In November/December 2016, EPA tested outdoor air from four locations in Eastern Heights over three days. TCE was detected in the west air monitoring station near Highway 332 at a low level below the screening level. (See sampling report dated March 17, 2017.)

Throughout the sampling events, chemicals related to gasoline—like benzene—were detected in the outdoor air in and around Eastern Heights and the Facility. These chemicals are common in the environment due to vehicle exhaust.

Residential Groundwater

During the fall of 2015, the Facility’s contractor collected groundwater samples with EPA oversight throughout Eastern Heights. These samples showed TCE contamination 15 to 50 feet below ground (generally within the southern part of the neighborhood). (See sampling report dated June 1, 2016)

Due to the potential for contaminants in the shallow groundwater in Eastern Heights to form vapors that can lead to air contamination, EPA has been conducting an extensive outdoor air and vapor intrusion study (indoor air) in Eastern Heights and the surrounding area (see sections on indoor air and outdoor air above).

Local Surface Water

In January 2016, EPA collected two surface water samples from Riverdale Creek (west of the Facility) and two surface water samples from a stormwater retention pond (former equalization lagoon) on the Facility property. Concentrations of TCE were detected above EPA maximum contamination levels (MCLs) in the two samples collected from Riverdale Creek. No contaminants were detected in either of the other two surface water samples from the on-site pond. (See sampling report dated April 5, 2016)

On October 26, 2015, the Mississippi Department of Environmental Quality (MDEQ) issued a water contact advisory for the lower segment of Riverdale Creek. ExitPeople are advised to avoid swimming, wading, drinking, fishing or eating fish from these waters. MDEQ is continuing to conduct sampling of Riverdale Creek and has issued two separate fact sheets, in January 2016 Exitand October 2016,Exit summarizing the findings. The advisory will last until sampling results show conditions at the creek no longer pose a human health risk.

Residential Soil and Soil Gas

EPA directed the Facility to conduct two rounds of soil gas sampling in Eastern Heights during the fall of 2015 and spring of 2016. EPA oversaw the installation of soil gas vapor ports by the Facility’s contractor along the south and southeast perimeter of the Eastern Heights neighborhood. No Facility-related chemicals were detected above screening levels. (See sampling report dated June 1, 2016.)

In May 2016, EPA collected soil samples from the playground on Tallahoma Drive from areas where children are most likely to come into contact with the soil (e.g., beneath the swings and at the bottom of the slide). No TCE or TCE-related chemicals were detected in the soil at the playground. (See sampling report dated August 26, 2016.)

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