When the relief valve sends hot water through the
discharge pipe, it is important that it be expelled where moisture damage is unlikely to occur.
With the proper permits, dischargers can dump toxic levels of chemicals inside these mixing zones -- as long as they meet water-quality standards when measured at a set distance from their
discharge pipes. The mixing zone is the volume of water adjacent to the
discharge pipe that is permitted to exceed state and Federal water quality standards.
* Check the coarse refuse
discharge pipe. Good abrasive should not be visible.
Keller says before the revisions to the Fisheries Act were made, mining companies were only required to monitor what was coming out of their
discharge pipes. The new legislation package places the onus on miners to monitor the downstream effects of effluent as well.