Private Septic Systems

General Information:

In Iowa, local boards of health have primary responsibility for regulation of sewer systems serving 4 homes or fewer or less than 15 people, while the Iowa DNR has primary responsibility for larger (public) systems. In conducting their activities, counties must comply with the minimum state standards developed by the Iowa DNR. If counties fail to adopt or enforce state standards for smaller systems, the Iowa DNR has concurrent authority to require compliance with the minimum standards for onsite wastewater treatment and disposal.

The Iowa DNR standards specify sitting and construction requirements relative to the primary and secondary treatment portions of the sewage disposal systems, minimum depth to groundwater, minimum separation distances to potable water sources, and maximum percolation rates for soils. These standards are primarily a prescriptive code giving design criteria for each alternative type of secondary treatment system permitted. Counties have the authority to allow alternative or innovative performance based systems.

Licensing and Certification:

The Iowa DNR certifies time of transfer septic system inspectors for inspections at the time of sale for buildings with private sewage systems. For more information on certification for time of transfer inspectors, please see the Time of Transfer webpage.

In addition, the Iowa DNR is responsible for licensing commercial septic tank pumpers and cleaners. For more information on the licensing of septic tank pumpers and cleaners, please see the Septic Tank Pumping webpage. The county boards of health are responsible for enforcement of the septic regulations and inspections.


Because of the responsibility the counties have in this area, the Iowa DNR provides an annual training for new county sanitarians. The Iowa DNR actively works with the counties to improve their enforcement programs and train their staff.

The Iowa DNR has partnered with Des Moines Area Community College (DMACC) to develop a training center and curriculum covering onsite (private) wastewater systems. The training is provided statewide at various locations at least 10 times annually and covers all topics related to onsite wastewater systems. The Onsite Wastewater Training Center of Iowa, located at the DMACC Ankeny campus, includes numerous displays of onsite wastewater technology. The training is designed for county sanitarians, septic system installers, pumpers, and designers, but it is open to everyone.

The Iowa Onsite Wastewater Association (IOWWA) also provides training opportunities and information regarding private septic systems in Iowa.


Funding is available for loans to individuals to replace inadequate onsite sewer systems. Please see the following links for more information in individual septic system loans: OSWAP Loan Program and USDA Rural Development.

Iowa Administrative Code Chapters regarding septic systems and onsite wastewater:

Chapter 68: Septic Tank Cleaners
Chapter 69: Onsite Wastewater Treatment and Disposal
Chapter 93: Onsite Wastewater Systems Assistance Program

Helpful Links:

Residential Onsite Wastewater Treatment Overview
Septic System Diagram
County Sanitarian List
US EPA: Septic Systems (Onsite/Decentralized)
Onsite Wastewater Training Center
Iowa Environmental Health Association
Chapter 69 Waiver Request Form