Pretreatment Program
The Rochester Water Reclamation Plant (WRP) controls the discharge of industrial wastewater in accordance with the Federal Clean Water Act. This is done through the Industrial Pretreatment Program, which includes issuing permits, conducting inspections, and collecting periodic samples.
The program establishes discharge limitations and prohibits certain substances to protect the sanitary sewer collection system infrastructure, the WRP, plant personnel, and the environment.
For example, the discharge of acidic liquids with a pH below 5 is prohibited to prevent corrosion of sanitary sewer pipes. Liquids with a pH greater than 11 are prohibited, as they can release dangerous gases, such as ammonia, posing a threat to anyone working nearby. While the WRP is effective at mercury removal, a maximum influent concentration 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 potential for accumulation in local fish.
Prohibited substances and discharge limitations are found in the Rochester Code of Ordinances 12-2. Some aspects of the industrial pretreatment program involve recovering costs associated with treating wastewater and hauled waste with higher-than-normal strength. These costs are outlined in the Rochester Code of Ordinances 12-6, along with Rochester City Council resolutions that set the rates.