COASTAL PLAIN TREATING COMPANY
TIFTON, TIFT COUNTY, GEORGIA
CERCLIS NO. GAD980844559
November 18, 1998
Exposure Investigation and Consultation Branch
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry
TABLE OF CONTENTS
The U.S. Environmental Protection Agency (EPA) Region IV requested the Agency for Toxic Substances and Disease Registry (ATSDR) to review the results of fenceline and off-site time weighted air samples obtained from the Coastal Plains Treating Company Site in Tifton, Georgia, and comment on whether removal activities created concern for off-site inhalation exposure. Specifically, EPA would like to know if dioxin and furan contaminated dust posed a health threat to the public during removal activities.
The Coastal Plains Treatment Company is a 3.8 acre site and is bounded on the west by residences (across Widden Road). A few more residences are a few hundred feet south of the property. The Coastal Plains Treatment Company is not in operation, but from 1946 until 1985 the site was used as a wood treatment facility. Wood was dipped into a container of creosote preservative and then allowed to dry on racks. Wastewater from this process was discharged to a shallow (unlined) pond on-site. The site was also reported to have been used to store hazardous materials, however, those materials have not been identified. The site owner had sediments from the unlined pond excavated and stored on-site in the mid 1980s .
During December 10-11, 1997, January 21-22, 1998, and March 25, 1998, Science and Ecosystem Support Division at EPA's request collected air samples (number not indicated) from the southeast corner of the site, an area adjacent to the spill area on-site, and a background sample from off-site (see attached map). Samples CP-5, CP-3A, CP-3B, and CP-4 were collected from the area with the highest dioxin concentration in soil, and samples CP-1,CP-2, and CP-7 were collected from an area near the residences (see attached map).
This sampling was conducted to determine if polychlorinated and polybrominated/chlorinated dibenzo-p-dioxins and dibenzofurans were being released into ambient air prior to and during soil removal activities at the site . The sampling locations were determined each day based on the meteorological conditions . All air samples were collected and analyzed in accordance to EPA's TO-9 Method for the Determination of Toxic Organic Compounds in Ambient Air . Air samples were collected at a flow rate of 220 liters per minute, and the sampling interval was set at 24 hours.
Dioxins/furans are semi-volatile organic compounds that bind tightly to soil. EPA's contractors conducted air sampling for dioxins and furans prior to and during excavation of contaminated soils.
Last spring, ATSDR evaluated the air monitoring data and reported verbally to EPA that exposure to dioxins/furans contaminated dust during remediation activities did not represent a health threat to the public. The estimated exposure dose does not exceed ATSDR's Minimal Risk Level (MRL) or EPA's Reference Dose (RFD) for dioxins/furans. The MRL and RFD represent the amount of chemical that a person can be exposed to for a certain duration that is unlikely to cause adverse non-cancerous health effects. Also, the estimated exposure does not pose an increase in cancer risk for the general public.
Based on the data reviewed, ATSDR concludes that exposure to dioxins and furans that were contained in site-related fugitive dust from excavation activities does not pose a health threat to the general public.
None2. Memorandum, Coastal Plains Air Dioxin Monitoring Results, from Danny France (Science and Ecosystem Support Division) to Charlie Fitzsimmons, EPA's OSC, July 28, 1998.
Robert L. Williams, Ph.D