General Permit #4

Discharge from Onsite Wastewater Treatment and Disposal Systems

Any onsite wastewater treatment system that discharges treated wastewater to a designated water of the state or a subsurface drain tile must be monitored to ensure that it continues to meet secondary treatment standards.

To achieve these standards, all surface discharging onsite systems that discharge to a designated water of the state or a subsurface drain tile must obtain coverage under NPDES General Permit #4 and must meet all the monitoring requirements of the permit. A Notice of Intent (NOI) form must be filed with the NPDES Section of the Iowa DNR prior to the installation of the discharging onsite system. The NOI form may be obtained from the county sanitarian or downloaded below. The completed NOI must be sent to the Iowa DNR at the address noted on the form. Once the form is received, the Iowa DNR will issue a General Permit #4 to the system owner. There is no fee associated with permit coverage.

542-1541 NPDES General Permit #4: Notice of Intent (NOI)
542-1541 NPDES General Permit #4: Notice of Intent (NOI)

NPDES General Permit #4: General Information and Conditions

The treatment system owner is required by General Permit #4 to maintain records of operation and sample the discharge from the onsite wastewater system. These requirements are in addition to any county construction or operating permit requirements for the system. The owner is required to make arrangements for the test samples from the system to be analyzed by a certified laboratory. To find a certified laboratory, please use the State Hygienic Laboratory certified laboratories search.

Any questions or comments regarding General Permit #4 should be sent to Tim Grotheer,, 515-725-8414, NPDES Section, Department of Natural Resources, 502 E. 9th Street, Des Moines, IA 50319-0034.

Stakeholder Meeting to Discuss Proposed Changes to NPDES General Permit #4 for Private Sewage Disposal Systems:

  • Tuesday, December 7, 1:30pm – 2:30pm, Teleconference (Zoom)
  • Registration is required for this public hearing. Please register using the following link:
  • Meeting ID: 834 7754 3104, Passcode 4Wb@cH
  • To Join via audio, dial: +1 312 626 6799 US (Chicago), Meeting ID: 834 7754 3104

The DNR is hosting an informal stakeholder meeting on Zoom for proposed changes to NPDES General Permit #4, which covers discharges to private sewage disposal systems. Any persons who intend to attend the meeting and have special requirements should contact the Department and advise of specific needs.

Written Comments on Proposed Changes to General Permit #4:

Any interested person may submit comments concerning the proposed changes to General Permit #4. Submit written comments by 4:30 p.m. on December 17, 2021. Direct comments or questions to:

Cory Frank, Wallace State Office Building, 502 East 9th St., Des Moines, Iowa 50319

Email: or 515-689-7941