Wastewater & NPDES Rules

Wastewater Rule Chapters

The Iowa Administrative Code (IAC) contains several chapters regulating the direct discharge of wastewater to waters of the state. The chapters containing most of the wastewater permit regulations are as follows:

• 567 IAC Chapter 60: Scope of Title, Definitions, Wastewater Construction Permits, and Operation Permits - definitions for Chapters 60 through 69; requirements for wastewater construction permits; requirements for operation, individual, storm water, and General Permits NPDES permits; public participation procedures; guidelines for completing a Notice of Intent for a General Permit; terms and conditions of permits;  fees.
• 567 IAC Chapter 62: Effluent and Pretreatment Standards: Other Effluent Limits or Prohibitions - prohibited discharges; secondary treatment standards; federal effluent and pretreatment standards; reuse of treated effluent.
• 567 IAC Chapter 63: Monitoring, Analytical, and Reporting Requirements - pollutant test procedures; requirements for monitoring records, toxicity testing, and bypassing; monitoring tables; references the Supporting Document for Permit Monitoring Frequency Determination.
• 567 IAC Chapter 67: Standards for the Land Application of Sewage Sludge - land application, reporting, and testing requirements for sewage sludge.
• 567 IAC Chapter 61: Water Quality Standards - more information on Chapter 61 can be found on the Water Quality Standards webpage.
• 567 IAC Chapter 65: Animal Feeding Operations - more information on Chapter 65 can be found on the Animal Feeding Operations webpage.
• 567 Chapter 68 - Commercial Septic Tank Cleaners and 567 IAC Chapter 69 - Private Sewage Disposal Systems - More information on these chapters can be found on the Private Septic Systems webpage.
• Chapter 64 and Chapter 66 have been rescinded as of May 14, 2025; effective June 18, 2025.

The chapters above are regularly updated through the state's rulemaking process. Please refer to the Current NPDES Rulemaking Actions section below for more information on any proposed rule changes.

Current NPDES Rulemaking Actions

Renewal of General Permit #4

The DNR is hosting an informal stakeholder meeting on February 4, 2026, regarding the renewal of NPDES General Permit #4 (GP #4) for discharges from private sewage disposal wastewater systems (also known as onsite systems). The purpose of this meeting is to accept comments and answer questions on changes to GP #4. The current general permit expires on February 28, 2028. Formal rulemaking to renew GP #4 is expected to begin in mid 2026. More information on the meeting and a redline-stakeout version of the informal draft renewal permit is available on the General Permit #4 webpage.

Renewal of General Permits #5, #6, and #7

The DNR is hosting an informal stakeholder meeting on March 3, 2026, regarding the proposed five-year renewals of NPDES General Permits #5, #6, and #7 (GPs #5-7). The purpose of this meeting is to accept comments and answer questions on possible changes to GPs #5, #6, and #7. The DNR is specifically seeking comments on the clarity, feasibility, and potential impact of the proposed changes. All three of the general permits will expire on June 30, 2028. Formal rulemaking to renew these GPs is expected to begin in mid 2026. More information on the meeting and a redline-stakeout version of each of the informal draft renewal permits is available on the General Permit #5, General Permit #6, and General Permit #7 webpages.

Past NPDES Rulemaking Actions

2024-2025 Water Quality Bureau EO10 Rulemaking

Executive Order 10 (EO10) signed by the Governor on January 10, 2023, requires all state agencies to identify administrative rule chapters that will be retained or rescinded. The EO10 process for both the review of existing rule chapters and the reauthorization of rule chapters includes public engagement with the opportunity for meaningful input throughout the process. More information on the changes to the wastewater rules that were made in Spring 2025 as part of the EO10 process is available on the Water Quality Bureau Rulemaking webpage.

Summary of Rulemaking Procedures

When the NPDES Section is considering a change to the wastewater rules, a draft rule package is developed and a public meeting is scheduled to gather initial stakeholder input on the draft rules. After the initial stakeholder comments are incorporated into the draft rules, the NPDES Section prepares an internal rulemaking package for review by DNR Legal staff and the Governor's Office. Once DNR Legal staff and the Governor's office have reviewed and approved the proposed rule, the rulemaking package is presented to the Iowa DNR Environmental Protection Commission (EPC) for approval as a Notice of Intended Action (NOIA). If approved by the EPC, it is published in the Iowa Administrative Bulletin (IAB) as an NOIA. Once the NOIA is published, the rule is discussed at the next legislative Administrative Rules Review Committee (ARRC) meeting. After a public comment period in which hearings are held and comments are accepted, the proposed rule is presented to the EPC for approval as a Final Rule. If a final rule is approved by the EPC, after consideration of public comments, it is published in the Administrative Bulletin as a Final Rule. The final rule will be presented to the ARRC after it is published and before it becomes effective. Please see the summary steps below:

Draft rule package prepared - Public meeting on draft rule - Comments incorporated into draft rule - DNR Legal review - Governor's Office review - NOIA presented to the EPC - NOIA publication in the IAB - ARRC review of NOIA - Public comment period - Responsiveness summary prepared - Final Rule presented to EPC - Final Rule publication in the IAB - ARRC review of Final Rule - Final Rule becomes effective