TOXICITY Oi^ TWO CHLORINaTi:;D CATJiCHOLS, 

 POSSIBLJi COMPONMTS OF KRA.FT PULP KILL BLjLACH WaSTK^- 



IlYrKODUCTION 



At present, tliree bleached kraft pixLp mills are operating in 

 the Fraser River watershed (FIGUfiL 1). The first mill, located at 

 Kamloops, began operation in December, 1965, followed by two mills 

 at Prince George which began operation in the spring and summer of 

 1966, A third mill is now under construction at Prince George 

 while another is planned for Ciuesnel. Wastes produced by these 

 mills are discharged, after treatment, to the Fraser and Thompson 

 Rivers, both utilised as migration routes by major populations of 

 juvenile and adult sockeye ( Oncorhynchus nerka) and pink salmon 

 (0. gorbuscha ) . Downstream segments of both rivers also serve as 

 incubation areas for the majority of the pink salmon produced from 

 the Fraser system. Kamloops Lake, located downstream from the 

 Kaialoops pulp mill, also serves as a sockeye rearing area. 

 Elimination of toxic effects from mill wastes is thus vital to the 

 protection of this valuable fishery resource. 



Wastes produced by the mills, originating mainly from bleaching 

 operations, are treated in biological treatment systems before being 

 discharged, according to specifications drafted by regulatory 

 agencies. Although biological treatment has effectively reduced 

 acute toxicity of bleach wastes, further information is desired 

 defining the toxicity of specific compounds in the wastes both 

 before and after treatment. In order to fully understand possible 

 ill effects of pulp mill discharges, even after treatment, lethal 

 and sublethal levels of individual bleach waste toxicants should 

 be determined. Through usu of this knowledge, specifications and 

 regulations can be developed which will assure that conditions safe 



■"■ This research was sponsored by the Governments of Canada and 

 the United States with a part of the United States contribution 

 originating from the Federal Water Pollution Control Administration 

 of the U.S. Department of the Interior. 



