The program sets discharge limitations and prohibits certain substances so as to protect the sanitary sewer collection system infrastructure, the WRP, plant personnel, and the environment.
For example, discharge of acidic liquid with a pH lower than five is prohibited to prevent corrosion of sanitary sewer pipes. Liquids with a pH of greater than eleven are prohibited as they can cause the release of dangerous gases, such as ammonia, posing a threat to anyone working nearby. While the WRP is effective at mercury removal, a maximum concentration of mercury is enforced because if influent concentrations become too high, mercury may not be completely removed and will be discharged into the Zumbro River. This mercury then poses a threat to the environment including the possibility of accumulating in local fish.
Prohibited substances and discharge limitations are found in the Rochester Code of Ordinances 12-2. The Water Reclamation Plant has outlined some common Businesses That Require Wastewater Review prior to wastewater discharge to the system. In addition, some aspects of the industrial pretreatment program involve the recovery of costs associated with treating higher than normal strength wastewater and hauled waste. These costs are outlined in the Rochester Code of Ordinances 12-6 in combination with Rochester City Council resolutions outlining rates.
