UTILITY RIGHT-OF-WAY CONTAMINANTS - POLYCYCLIC AROMATIC-HYDROCARBONS

Utility right-of-way (ROW) ditches flowing into salmon (Oncorhynchus s pp.) streams in the Lower Mainland and Vancouver Island of British Col umbia, Canada, were sampled in 1990 and 1991 to determine the presence of polycyclic aromatic hydrocarbons (PAHs). Ditches of parklands, far mlands, and railway ROWs were also sampled to establish background and reference PAH concentrations. While PAHs were not detected in ditches of parklands, they were found in farmlands and in utility and railway ROW ditches. Concentrations of PAHs averaging 5.6 mu g/L and 0.79 mg/ kg were found in ditch water and sediments of farmlands, respectively. In utility ROW ditches, PAHs in water adjacent to treated poles avera ged 551.7 mu g/L, compared with a mean level of 23.2 mu g/L 4 m downst ream; is sediments collected from the same sites, the mean concentrati on of PAHs was 15 mg/kg and 3.3 mg/kg, respectively. Soils at the base of utility poles showed a mean PAH concentration of 3076 mg/kg, while wood chips/splinters from treated wood poles and railway ties contain ed about 62 000 mg/kg and 16 000 mg/kg PAHs, respectively. Levels of P AHs found in ditch water adjacent to treated poles did not exceed the 96-h LC(50) (lethal concentration of a chemical to 50% of the test fis h population) of salmonids and aquatic invertebrate. The biological im plications to these animals of exposure to low level PAH-contaminated ditch sediments are discussed.