States that have NPDES authority are required to develop pretreatment programs for EPA approval. States are granted pretreatment authority by the EPA if they show that their program meets all federal requirements. States with pretreatment authority are referred to as pretreatment-delegated states. Iowa was delegated pretreatment authority by EPA in 1982.

The POTWs develop local pretreatment programs which are approved either by the state (in pretreatment-delegated states) or by the EPA. Once a program is approved, the state or the EPA conducts periodic checks to ensure that the program is operating properly.

If a POTW does not have an approved pretreatment program, national pretreatment standards and requirements are enforced by the state (in pretreatment-delegated states). Thus, the EPA, the state, or the POTW may enforce pretreatment regulations.

The POTWs develop local pretreatment programs, which implement federal standards and protect local interests. They prepare detailed pretreatment program documents, which are reviewed by the state, in pretreatment-delegated states, or by the EPA. To gain approval, these submissions must meet the requirements for local pretreatment programs contained in 40 CFR 403.

To be successful, the local pretreatment programs must have the following elements:

• Building Blocks: Local pretreatment programs require legal authority, a professional staff, funding, and an information base on the industrial dischargers.
  
  
• Effluent Limits: For industrial users of the sewage system, effluent limitations that enforce federal standards and protect local interests must be established.
  
  
• Implementation Activities: POTWs must undertake a number of activities to implement their effluent limits including notification, permit administration, inspection, monitoring, and enforcement.
  
  
• Information Handling and Public Access: Pretreatment programs must include a data management system and must provide mechanisms to allow the public to have access to information about the program and to comment on program elements.