LCP Chemicals Superfund Site

ARCO Neighborhood Soil Sampling Results
 

Overview

The “Data Report of Off-Site Soil Sampling, LCP Chemicals Superfund” dated April 2005, and an ATSDR Public Health Consultation based on the report were received for review. The Environmental Protection Agency Data Report document bears the warning legend: “DRAFT: Do not cite or quote” making it difficult to comment directly on the data or discussion contained within the report. Overall the report indicates there is no future cause for concern among residents. The testing shows no plumes of chemicals moving from on-site into the neighborhoods.

Background

The LCP Chemicals Superfund site was the location of several industrial chemical plants producing bleach, petroleum products, or paint. These operations left the area contaminated with known chemical toxins from ground, water and air pollution.  The 550-acre site of uplands, buildings and marsh front along the Turtle River in Glynn County Georgia is in the process of being cleaned with Federal and State oversight.

During an emergency cleanup several years ago soil testing data in the neighborhoods surrounding the site indicated a potential problem. Site chemicals appeared in a significant number of samples, although in amounts too low to be harmful. The Environmental Protection Agency promised residents at that time a more thorough study would be conducted to verify or eliminate the possibility of harmful levels off-site.

Various industries at the site used “stacks” and fans to vent waste chemicals into the air, and the ARCO neighborhood is in the pathway of any possible contamination. In an earlier evaluation the Environmental Protection Agency noted: “It is very likely that this airborne deposition traveled with prevailing winds, and mercury was therefore distributed over a potentially rather large area. The prevailing wind direction for this area is from the northwest, away from the marsh area.” [ Section 7.1.3, airborne redeposition (page 42, Operable Unit One Upland Soils and Estuary March 2002)].

 The current testing is that promised study. The study was designed with oversight from agencies such as the Agency for Toxic Substances and Disease Registry (ATSDR), State of Georgia Environmental Protection Division (Ga EPD) and Glynn County Health Department, also with input from the Glynn Environmental Coalition. Several meetings were held during this process to garner public input as well.

 The Testing Plan

There were two possible patterns of toxin occurrence that could result from nearby operations. One would be a plume extending from the plant site into the neighborhood whereby properties closest to the fence line would have the highest rates of contamination. A second pattern is often called “heterogeneous” contamination, meaning that “hot spots” of contamination occur randomly over an area. A “block-by-block” approach was taken for the testing where each block of homesites in the area was tested by subdividing into grids and using composite sampling. This type of grid would detect either the plume or “hot spot” contamination, with the added benefit that each block could be told their property had been tested and found clean, or remediated on a case-by-case basis. The study was divided into two phases, with the nearest homesites tested in phase 1, and the phase 2 testing only occurring as needed. 

Composite sampling takes several individual samples and mixes them into one sample for testing. Generally composite sampling is more effective for plume-type contamination than for the “hot-spot” type of contamination since hot spots can be diluted with uncontaminated soil using composite samples. Since the plume-type of contamination was the most likely form for airborne deposition into the neighborhood composite sampling made sense. Had any of the composites samples shown evidence of “hot-spot” type contamination the GEC would have insisted on resampling using the discrete single-sample methods.

Soil samples were tested for Mercury, Lead, Arsenic, PAH (chemicals that can cause cancer), and PCB. There were two types of samples: shallow surface samples from the upper three inches, and deeper surface samples from the top foot. These different methods were used to satisfy differing requirements for estimating risk used by EPA and ATSDR. Effort was made to select samples where deposition could have occurred decades ago—away from trees and structures and with no evidence of human disturbance or covering over. Residential cleanup levels for the state of Georgia were used throughout.

 Results

Testing patterns were reasonable and methods to obtain bona fide representative soils appear adequate.

PAH-We would not expect to find PAH in surface soil samples more than 10 years after airborne deposition. Aromatic hydrocarbons are volatile, light sensitive, and digested by soil bacteria. It was no surprise that PAH was not found.

PCB- the presence of Aroclor-1268 in all of the samples at concentrations up to 440 µg/kg (Table 2) indicates the EPA was correct when stating “It is very likely that this [LCP] airborne deposition traveled with prevailing winds…” toward the ARCO neighborhood. The obvious source for this PCB is the site, so the neighborhood was contaminated, and probably was significantly contaminated during operations decades ago. At this point in time it is fair to say the PCB levels are not threatening and no remediation is called for. However, public health managers should note that long-term residents in this area may - emphasize “may”-  have been exposed in the past to high levels of Aroclor-1268.

Mercury-Levels of Mercury found are considerably less than the levels set by the state of Georgia for residential areas. The levels are higher than some studies suggest are safe; however, this review is not the place for that debate. Mercury levels shown in Tables 2 and 3 for the neighborhood are below the levels required for action.
Lead- One composite had a high Lead reading, high enough for concern at that point in the neighborhood. There is no pattern suggesting a plume of Lead—the reading is a single “hot spot” of high Lead. EPA’s report argues for Lead paint chips as the source of the high Lead reading, but they provide no evidence to prove or disprove that conclusion. We would prefer to see more Lead testing in this neighborhood. 

Heavy metal contamination can occur in “hot spots” and additional spots could be missed by the grid format of composite sampling.

Arsenic- Tables 2 and 3 indicate Arsenic is slightly elevated in neighborhood soils, but not at levels that cause concern. Both the amount and type of Arsenic is important in determining risk, and these levels are low enough to indicate no further studies are needed.

Other compounds—No other compounds were found at levels that raise concerns.

 Conclusions

 “Is the ARCO neighborhood safe from LCP toxins?” Yes. Studies are rarely definitive, but this one comes very close. With the exception of the single Lead “hot spot” --which should be clarified with a follow-up study-- this study shows that the LCP Superfund Site will not impact the future health of the Arco neighborhood residents.

 Written by R. Kevin Pegg, Ph.D.; edited by Dr. Mary S. Saunders. Copies of the Technical Assistance Report are available from the GEC, at the Glynn County library, or at www.Enviro-Issues.net  on the Internet.

LCP SUPERFUND SITE TECHNICAL ASSISTANCE REPORT

"This project has been funded wholly or partly by the U.S. Environmental Protection Agency under Assistance Agreement Number 1-994850-01-0 to The Glynn Environmental Coalition, Inc. The contents of this document do not necessarily reflect the views and policies of the U.S. Environmental Protection agency, nor does mention of trade names or commercial products constitute endorsement or recommendation for use." Volume 10,  Number 1, June, 2005