General Permit #4

Discharge from Onsite Wastewater Treatment and Disposal Systems

2017 proposed renewal of NPDES General Permit #4. The DNR will propose to renew GP #4 for 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 be registered under the NPDES General Permit #4 and meet all the monitoring requirements of that permit. A Notice of Intent (NOI) application form must be filed with the Wastewater Operation Section of the Iowa DNR prior to the installation of the septic system. The NOI form may be obtained from the county sanitarian or downloaded below. The completed application is then sent to the DNR. The DNR will then issue a General Permit #4 to the system owner. There is no fee associated with this requirement.

The owner will be required by the general permit, 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, Wastewater Operations (NPDES) Section, Department of Natural Resources, 502 E. 9th Street, Des Moines, IA 50319-0034.