143 



This commitment to pollution prevention continues today KPC is in the final design stage 

 of a major bleach plant modification that will allow elemental chlorine free (ECF) 

 bleaching and will result in a significant reduction in the formation of chlorinated organic 

 compounds. Other studies and designs are currently in progress to implement spill 

 containment and close up the screen room, both of which should aid in reducing the 

 toxicity of the mill's wastewater The pollution prevention study is another step in KPC's 

 ongoing process of minimizing the amount of waste generated by its manufacturing 

 operation. 



KPC's Pollution Prevention Study will be patterned after EPA guidance documents 

 provided by Region 10 ,Handbook on Pollution Prevention Opportunities for Bleached 

 Kraft Pulp and Paper Mills, EPA 600/R-93/098, June 1993 znd Model Pollution 

 Prevention Plan for the Kraft Segment of the Pulp and Paper Industry, EPA 9 1 0/9-92- 

 030, September 1992. In addition, KPC's study will incorporate an approach similar to 

 those used by the states of Washington (WAC 173-307) and Texas (TAC 335 Subchapter 



Q) 



KPC routinely collects a significant amount of analytical data to document chemical 

 purchases and releases to the environment (air, water, solid waste,) This existmg 

 information will form the database for the pollution prevention study 



Chronic Toxicity 



Chronic toxicity is defined by the particular bioassay tests performed on an effluent The 

 rationale behind toxicity testing is to measure the combined effects of all individual 

 components of an effluent in terms of biological toxicity to a selected aquatic life form or 

 life stage. KPC is committed to reducing final effluent chronic toxicity 



In previous attempts to identify specific sources of chronic toxicity at KPC, researchers 

 were able to narrow the contributors of the greatest chronic toxicity to a small number of 

 sources and to identify broad classes of chemical constituents that may account for the 

 measured toxicity Based on this internal research, a number of preliminary conclusions 

 have been reached: 



• Different compounds may account for toxicity to different marine test 

 organisms, i e., what is chronically toxic to sea urchins may not be toxic to 

 oysters or mussels (and vice versa) 



• Chronic toxicity in the mill internal effluent streams cannot be added and 

 subtracted, as is the case with more conventional contaminants such as 

 BOD and TSS The synergistic or antagonistic effects of multiple 

 compounds when mixed together may resu't in increases or decreases in 

 the combined toxicity This makes the study of individual contributing 

 sources very difficult, and the results of internal effluent stream studies are 



25 



