General Permit #4

Discharge from Onsite Wastewater Treatment and Disposal Systems

The Iowa DNR has proposed to renew NPDES General Permit #4 for five (5) years with no other changes. You can view the proposed GP4 renewal here.

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 Wastewater Operation 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 the permit.

The 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.

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

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