The GAO 150 site is a former vermiculite expansion facility that began operations under the ownership of the Universal Zonolite Insulation Company (later changed to the Zonolite Company). Vermiculite ore was received for dry ore processing and expanding at the GAO 150 site from mines located in Tigerville and Ignore, South Carolina from 1946 to 1956. In 1956, a more efficient wet ore processing plant was opened in Enoree, South Carolina and ore processing at the GAO 150 site ceased. Vermiculite concentrate continued to be expanded at the GAO 150 site, however, with shipments of concentrate mainly coming from the Enoree ore processing facility. W.R. Grace bought the Zonolite Company in 1963, and the purchase included the GAO 150 site. Aside from receiving local vermiculite ore and concentrate, W.R. Grace records indicate that as much as 11,203 tons of vermiculite concentrate were shipped from the W.R. Grace (formerly Zonolite) vermiculite mine in Libby, Montana to the GAO 150 site from 1956 to 1981. Vermiculite from the Libby, Montana mine is known to contain a percentage of asbestos.  At the time of the September 2009 field event at the GAO 150 site, the facility was closed and the equipment used for vermiculite expansion had been removed.

The GAO 150 site is located about 6.5 miles north-northwest of downtown Greenville, South Carolina, in a mainly rural area interspersed with residences and residential communities. Furman University is located approximately one mile south of the GAO 150 site. A few industrial facilities border the GAO 150 site to the north. A retirement community adjoins the GAO 150 site along its southern perimeter. Residential properties adjoin the GAO 150 site along its southeastern perimeter, and many other residences and residential communities are located in the immediate vicinity of the site.

On September 22 and 23, 2009, and February 15, 2011, Tetra Tech, EPA, and REAC personnel conducted aggressive air sampling, ABS sampling, and bulk material sampling at the GAO 150 site.

On February 15, 2011, during a follow-up assessment by OSC Stilman and START, additional bulk sampling was conducted.  The follow-up assessment was conducted to determine the need for additional action based on previous sampling and the demolition of Site buildings.  Particular attention was focused on the biking/running trail.  During that follow-up assessment suspected vermiculite material was observed within several feet of the trail. 

Material that appeared to be vermiculite concentrate was noticed on the ground along the west side of the bike trail and in at least one place along the east side of the trail. 

The coverage of this material was especially heavy on and around a concrete slab located near the trail and just south of what is thought to have been the southern boundary of the building complex formerly located on the west side of the bike trail. This material did not appear to be contained within silt fencing, and potentially at risk of being spread both through wind transport and as a result of rain event-related surface water flow. The majority of the bike trail appeared to be unpaved and consisted of gravel and bare dirt. Walkers, runners, and bicyclers were observed on the trail throughout the EPA/START site visit.  Two bulk material samples were collected from the GAO 150 site during the site visit. 

Analytical results conducted by visual estimate indicated that levels as high as 5 percent asbestos identified as tremolite were detected. 
 

Given the changes to the Site, proposed development of the property for residential or other use and recent discovery of high levels of asbestos containing vermiculite at land surface, OSC Stilman issued a Notice of Federal Interest to the land owner, W. R. Grace.

On 05/18/2011, EPA, START, W. R. Grace and W. R. Grace's contractor arrived on-scene to conduct extent of contamination sampling in anticipation of a removal action.  36 bulk sampling location were selected adjacent to the bike/running trail.  An additional 8 locations were selected at suspect areas around the Site.  EPA provided oversite, sampling assistance and split samples with W R Grace.  Sampling activities were complete and the site was demobed on 05/19/2011.

Based on analytical results, additional excavation areas, adjacent to the trail, were added to the scope of the removal action.

2.1.1 Narrative

2.1.2 Response Actions to Date

WR Grace provided EPA, with a removal action plan for conduct of the clean-up.  Upon review and approval of the plan and based on the analytical, excavation occured at three separate areas at the Site.

During the reporting period the following occurred (OSC Stilman, OSC Harper and START conducting oversite):

Concrete Pad activities:

From 7/8/11 until 7/12/11, JBR Environmental Services continued removal activities on and in the vicinity of the concrete pad that formerly housed the silos.  Additional activities included:

• Use of vacuum truck and brooms to remove visible vermiculite and clean the concrete pad.  Areas addressed included the concrete pad as well as the adjacent shallow trench that was excavated along the eastern edge of the pad (between the pad and the walking path).
• A total of 5 rolloff containers (total of approximately 50 cubic yards) and 1 vacuum truck (estimated 3 to 5 cubic yards) were generated during pad cleaning activities and were shipped offsite for disposal.

On 7/13/11, Rogers & Callcott conducted ABS air sampling (walking scenario) on the concrete pad using 3 personnel (each with a 3 liter per minute pump and a 10 liter per minute pump).  Walking activities were conducted with sampling pumps running for a total of 60 minutes.

Backfill and Restoration Activities:

On 7/19/11, JBR personnel returned to the site to backfill, seed, and hay the areas of excavation.  Areas addressed during these activities include the excavations at N300 and S250 (former sampling locations) as well as the shallow trench that was excavated along the eastern edge of the concrete pad (between the pad and the recreational path).  Each area was backfilled with material that was previously cleared via sampling by Rogers & Callcott personnel (laboratory analytical for BTEX, PAHs, lead and PCBs).  Prior to demobilizing, JBR personnel also removed the high-visibility fencing from along both sides of the recreational path.

Site-Specific Action Levels and Clean-up Goals: 

The removal action level and clean-up goal for the Vermiculite Exfoliation Site GAO 150 are listed below. The clean-up goal was based on a college student scenario, which was the most conservative exposure scenario evaluated by EPA.

Action Level: 0.25% Libby amphibole asbestos
Clean-up Goal: 0.02 fibers/cubic centimeter (f/cc), for ABS

Conformation Bulk Sampling:

On 7/6/11 and 7/7/11 during the removal action, thirteen conformation bulk soil samples were collected by Rogers and Callcott. Four samples were collected from the northern excavation at N300, four samples were collected from the southern excavation at S250 and five samples were collected from the around the silo pad. All analytical results reported were below the site-specific action limit of 0.25% asbestos. The analytical results for the four samples at S250 were all reported as no asbestos detected, two samples at N300 were less than 0.25% asbestos and two were reported as no asbestos detected. Two samples collected adjacent to the silo concrete pad were reported as no asbestos detected and the other three sample adjacent to the silo concrete pad were reported as less than 0.25% asbestos.

Conformation Air Sampling:

On 7/7/11 and 7/13/11 during the removal action, thirteen conformation air samples were collected by Rogers and Callcott, nine ABS air samples and four background air samples. Of the nine ABS, three were collected in the excavation at S250, three in the excavation at N300 and three in the area of the silo pad. All air samples results reported were below the site-specific clean-up goal of 0.02 fiber per cubic centimeter (f/cc). The four background air samples results were reported less than detection limits of 0.001 structure per cubic centimeter (S/cc). Six of the nine ABS air samples reported results were less than 0.001 S/cc the remaining three ABS reported detectable levels of asbestos, S250 5 at 0.004 S/cc, Silo Pad 15 at 0.012 S/cc and Silo Pad 19 at 0.01 S/cc.

EPA co-located one ABS air sample with Rogers and Callcott ABS at the Silo Pad location. The co-located sample was to confirm WR Graces sample results. EPA sample GAO150-TT-AH-01 was collected by START and analyzed by a contract laboratory program (CLP) laboratory. The result was reported as no structures detected.

Final Site Visit:

On 9/14/2011, OSC Stilman and OSC Harper conducted a final site visit. The entire length of the Swamp Rabbit Trail located on the site had been graded, gravel placed on the trail, the trail was paved with asphalt and both sides of the trail have been graded smooth to the existing landscape.

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

W R Grace is the present owner of the property and the former operator of the facility and conducted the action under EPA oversite.

2.1.4 Progress Metrics