Exposure assessment of sewage treatment plant effluent by a selected chemical marker method.

Organic chemicals unique to sewage effluent can be useful as markers of an effluent plume. Samples were collected at a domestic wastewater outfall near Cocoa, Florida, and chemically characterized. Receiving waters were analyzed to determine the chemical components in the effluent most suitable for the assessment. The saturated hydrocarbon fraction and sterol fraction appeared to be of greatest utility for such purposes, and the concentrations of these fractions were determined for water, particulate matter, and sediment. Concentrations of the marker compounds decreased rapidly with increasing distance from the outfall.