US EPA

2191512 

Technical Report 

Flux of PCBs into water in Little Lake, Peterborough, Ontario 

Metcalfe, CD; Ferguson, ML; Metcalfe, TL 

1993 

BIOSIS/94/04112 

28 

2 

495-512 

English 

BIOSIS COPYRIGHT: BIOL ABS. The Otonabee River downstream of Peterborough, Ontario, has been contaminated with PCBs as a result of a history of industrial discharges into Little Lake. It has been suggested that downstream sites have become contaminated as a result of desorption of PCBs from contaminated Little Lake sediments. In a laboratory microcosm study, the PCB flux from Little Lake sediments, into water was calculated to be 0.4 mug/m2/d, which, when extrapolated to the sediment area of Little Lake, corresponds to a total PCB flux of 0.09 g/d. However, from analysis of water samples upstream and downstream of Little Lake, the total flux of PCBs from Little Lake was calculated to be 13.2 g/d. This discrepancy between calculated flux rates indicates that either the laboratory microcosm study underestimated PCB flux, or there is another source of PCBs in Little Lake other than contaminated sediments. The preponderance of highly chlorinated PCB congeners in water samples collected downstream of L