Private Onsite Wastewater Treatment Systems



Conventional In-ground Treatment

Aeration Treatment

Aerobic Treatment Units

Packed Bed Filters

Do's and Don'ts

Advantages and Disadvantages




Private onsite wastewater treatment systems treat domestic wastewater for discharge into the ground, typically in a soil absorption system.  Properly constructed and maintained systems effectively remove potential contaminants from the wastewater before interaction with ground or surface water.  Replacement of septic systems is very expensive, so regular maintenance saves money and time in the long run as it helps prevent system failure.

Maintenance Guidelines

  • Limit traffic over the distribution field such as livestock and heavy machinery
  • Only shallow rooted plants
  • Regular maintenance ie pumping on average every 4-6 years
  • Keep trees at least 20-30 feet away from field lines
  • Conserve water
  • Limit garbage disposal use
  • Don't dispose of anything except wastewater, human waste, and toilet tissue

A conventional system being installed


From Waukesha County Health Department


The observation pipe of a failing septic system

From Waukesha County Health Department

Human health is a concern while operating POWTS.  The effluent from POWTS must not cause a public health hazard when dispersed.  Therefore regulations such as distance from wells, property lines, and surface water must be strictly followed.  The requirements for POWTS in the state of Wisconsin are found in Comm 83 but here are some general requirements.


Size of septic system required is dependant on how many bedrooms in the household.

(100 gallons) (number of bedrooms) = estimated daily wastewater flow                                The system must be able to accommodate at least 150% of this value for a home.

For information about other onsite wastewater treatment systems, visit the EPA's website here.

This site was created for Environmental Public Health 441: Water and Wastewater at the University of Wisconsin Eau Claire

Valeri Gerberding, Kelsey Hustedt, Jessica Berti



 Created 12/08/04