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 DNR has primary responsibility for larger (public) systems. In conducting their activities, counties must comply with the minimum state standards developed by the DNR. If counties fail to adopt or enforce state standards for smaller systems, the DNR has concurrent authority to require compliance by individuals and the counties with the minimum standards for on-site wastewater treatment and disposal.

The DNR standards specify siting and construction requirements relative to the primary and secondary treatment portions of the sewage disposal systems as well as minimum depth to groundwater, minimum separation distances to potable water sources, and maximum percolation rates for soils. The DNR 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.

The DNR also licenses all commercial pumpers of septic tanks. Although the DNR is responsible for licensing of commercial septic tank cleaners, the county boards of health are responsible for enforcement of the regulations and inspections. In addition, the DNR certifies time of transfer septic system inspectors for inspections at the time of sale for buildings with private sewage systems.

Because of the responsibility the counties have in this area, the DNR provides an annual new sanitarian training. The DNR actively works with the counties to improve their enforcement programs and train their staff. In 2005, the DNR 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 is open to everyone.

Be aware funding is available for loans to individuals to replace inadequate onsite sewer systems: OSWAP Loan Program and USDA Rural Development.

Septic System Diagram
County Sanitarian List
Treatment Overview

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

Helpful Links:
US EPA: Septic (Onsite) Systems
Onsite Wastewater Training Center 
Iowa Environmental Health Association 
Iowa Onsite Wastewater Association 
National Onsite Wastewater Recycling Association