DEKALB PEST CONTROL SERVICES, INCORPORATED
AVONDALE ESTATES, DEKALB COUNTY, GEORGIA
The Dekalb County Health Department requested that the Georgia
Department of Human Resources (GDHR), Toxics and Health Hazards
Consultation Section (THHC), evaluate the extent of past and present
contamination and the potential for resulting health effects associated
with Dekalb Pest Control Services, Inc., a state-listed hazardous waste
site. This health consultation addresses the extent of cleanup at this
site, past contaminant levels, present contaminant levels, and the
potential or actual completed exposure pathways.
The Dekalb Pest Control Services, Inc. hazardous waste site is on the property of a single family house located at 135 North Clarendon Drive in Avondale Estates (Figure 1). The house is bordered by houses to the north and south, Clarendon Drive to the west, and dense woodland to the east.
The site was the operating facility for a commercial pesticide applicator from 1977 until January 1991 when a routine inspection by the Georgia Department of Agriculture (GDA) led to the discovery and reporting to Georgia Environmental Protection Division (GEPD) of the improper disposal of waste pesticide containers and rinsate from cleaning pesticide applicators in the wooded area behind the house. Laboratory analysis by GDA of soil samples revealed elevated levels of three pesticides in soil (Table 1). GEPD requested that the U.S. Environmental Protection Agency (EPA) conduct an immediate removal at the site. In response, officials from EPA and the Agency for Toxic Substances and Disease Registry (ATSDR) conducted a site inspection and further soil sampling (Table 2). Based on the site inspection report and EPA and ATSDR staff review of the analytical data, EPA declined to perform further action . This site entered the HSI database on November 17, 1994.
In January 1995, GEPD contracted for a sampling and analysis program to assess the extent of contaminated soil. Initial sampling results indicated that two pesticides reported to be at elevated levels in analysis of the 1991 GDA data had decreased through natural mechanisms (i.e. dilution). Chlordane was the only constituent above the GEPD Type 1 risk reduction standards (RRS) for chlordane in soil; therefore, no other pesticides were screened during the succeeding sampling events . The risk reduction standards established by the Georgia Rules for Hazardous Site Response define risk levels of regulated substances that are protective of human health and the environment. Type 1 standards are health-based cleanup levels for residential properties and provide for regulated substance concentrations that pose no significant risk on the basis of standardized exposure assumptions .
A sampling grid, 60 feet by 60 feet (Figure 2), was established by referencing the Field Assessment Report submitted by EPA and a visual inspection of the site. Based on analytical results (Table 3) a quantity of contaminated soil and excavation boundaries were determined.
In September 1995, GEPD contractors excavated and removed approximately 50 cubic yards (70 tons) of contaminated soil, which was incinerated. Following remediation, analytical results indicated that all chlordane levels were below Type 1 RRS for chlordane in soil (Table 4). The area was backfilled, graded, and reseeded. Field activities were completed in October 1995.
In July 1997, GEPD requested that a Compliance Status Report (CSR) be submitted to GEPD by the current owner of the property prior to removing the site from the HSI. The CSR requires that additional sampling be conducted to determine the nature and extent of background contamination both horizontally and vertically in soil and groundwater. This health consultation will be amended to include the results of the CSR and the final decision regarding HSI listing when data become available.