Septic Systems

septic system trench being dug

Nebraskans who live in rural areas often must rely on their own sewage treatment systems, called onsite wastewater treatment systems. The most common type of onsite wastewater treatment system used is a septic tank in combination with a drainfield.  Treatment starts in the septic tank where solids and liquids separate into layers and some microbial treatment of contaminants occurs.  The partially treated sewage moves to the drainfield where it is dispersed over soil and final treatment of contaminants (by microbial action, filtration, etc.) takes place.  Treated sewage is returned to the environment and enters groundwater.


There are two basic types of drainfields - gravel and gravelless.
A gravel drainfield system uses a perforated pipe embedded in gravel to accept and spread out sewage. Sometimes a chamber is used instead of the perforated pipe. A gravelless drainfield system uses a plastic chamber or pipe with filter fabric specifically designed for this purpose. Gravelless is a popular alternative where the cost of gravel is high, or in areas where access is difficult. However, some Nebraska counties do not allow gravelless systems.

Use and Maintenance

Proper use and maintenance of a septic tank and drainfield are crucial for the system to treat domestic sewage. Maintenance consists of periodically having the tank pumped by a certified pumper. Also, protecting the drainfield from compaction and being careful about what goes down the drain will help the longevity of a septic system.  A properly designed, installed, and maintained system should operate for 20 to 40 years or more, treating wastewater to minimize the negative impact on groundwater, surface water and human health.

In Nebraska, only a certified professional, registered environmental health specialist or professional engineer may design, pump, install or repair any onsite wastewater treatment system.

Septic Systems & Residential Lagoons - Made Easy for Homeowners
Click-through screens show everything you wanted to know about how systems operate and how to maintain.

Soil & Site Evaluation
Linked page with further information on the role of soil and site selection, soil permeability and testing.

Soil Survey Maps
Natural Resources Conservation Service maps.

Extension Publications on Septic Systems:

Septic Tank Design and Installation*

Traditional Drainfield Systems for Effluent Treatment*

Gravelless Drainfield Systems for Effluent Treatment*

Septic System and Drainfield Maintenance*

 *pdf format. Download the free Acrobat Reader

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