Research Article: Volatile organic compounds in Beech Creek, a tributary of Lake Columbia, Arkansas

Abstract

Volatile organic compounds (VOCs) are naturally and industrially produced organic chemicals that can exist in the air as gases. Most VOCs can easily be deposited in natural water through precipitation and point and non-point sources. Previous research has shown that the natural waters of Columbia County, Arkansas contain the following VOCs: vinyl chloride; bromoform; 1,3-dichlorobenzene; 1,2-dichlorobenzene; chloromethane; bromomethane; chlorobenzene; and dichloromethane. The purpose of this study was to determine if Beech Creek, a major tributary of Lake Columbia, contains these or other VOCs. Water samples were collected from seven bridges that cross Beech Creek. The samples were analyzed using a gas chromatograph (GC) equipped with a flame ionization detector (FID). Vinyl chloride was found to be the predominant VOC with concentrations from 3.92 to 7.16 mg/L. Trans-1,2-dichloroethylene, chlorobenzene, and bromoform were also found at concentrations of 4.69, 6.16, and 23.29 mg/L respectively. The Environmental Protection Agency (EPA) has designated VOCs as being either regulated or unregulated. Regulated VOCs are monitored with proposed Maximum Contaminant Levels (MCLs). Unregulated VOCs are monitored only to determine their presence in drinking water and have not been assigned MCLs. Vinyl chloride, trans-1,2-dichloroethylene, and chlorobenzene are regulated VOCs with MCLs of 2, 100, and 100 μg/l respectively. Bromoform is an unregulated VOC and does not have a MCL. The results show that Beech Creek has VOCs in its waters and that there is a slight possibility of VOCs contaminating local drinking water at levels higher than EPA standards.