Effluent. What is it?
Water is used within pulp and paper mills for processing, cleaning, rinsing, cooling, and many other purposes. The water entering mills is called “raw water.” After the water is used, it is treated and discharged. The discharged water is called “effluent.” Effluent is discharged to the
Kaministiquia River often referred to as the “receiving water.”
Why does effluent matter?
Untreated pulp mill effluent contains many substances that could be harmful to the environment, and could make the receiving water unsuitable for other purposes (such as swimming, fishing, etc.). Examples of these substances include dissolved wood components, small amounts of process chemicals, solids, and organic matter.
How do we control effluent?
To minimize the impact of effluent on the environment we adopt the following strategies:
- Use more environmentally-friendly chemicals within the pulp and paper mill;
- Recycle as much effluent as possible within the mill; and
- Treat the effluent to remove pollutants before discharge.
The Thunder Bay mill has a state of the art Primary and Secondary Treatment Plant that produces effluent well below regulatory limits.