The U.S. Congress created the national EPA-mandated Pretreatment program in 1972.
This program protects the nation’s wastewater treatment plants and waterways from discharges of toxic and other pollutants.
Many industries must pretreat wastewater before sending it to the sewer. This protects the wastewater treatment process, water quality, and facilities.
What Does Metro’s IPP Do?
The EPA approved Metro Water Recovery’s own Industrial Pretreatment Program (IPP) on August 25, 1986. Metro’s IPP administers pretreatment regulations to make sure the wastewater generated by industries in our service area is treated properly. Pretreatment also helps to protect Metro employees and the public.
Metro’s IPP team members work with businesses who discharge to our connectors. This includes several different types of activities:
- Identifying and maintaining a list of businesses
- Inspecting businesses
- Evaluating business operations and waste streams
- Notifying businesses of applicable requirements, which could include obtaining a Metro IPP permit and/or Implementing best management practices (BMPs)
- Collecting samples
- Reviewing data and reports
- Evaluating compliance
- Providing compliance assistance to businesses
- Taking formal enforcement action where necessary
Metro’s IPP also guides the Hauled Waste Program and the Dental Amalgam Control Program. Click the buttons below to learn more, or scroll down for more information about Metro’s IPP.


What Industries are Regulated by Metro’s IPP?
All businesses — including industrial, commercial and governmental establishments — that discharge anything other than normal sanitary wastewater are subject to the requirements of the IPP. Under its IPP, Metro does not have authority to regulate any domestic discharges from residences.
Are You an Industrial Partner?
View the resources below to get started. If you can’t find what you’re looking for, contact us using the form on this page. If you’re a dental office seeking information about the Dental Amalgam Program, click here.

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