Septic Systems

When is a Septic Permit Required?

Septic systems are reviewed and inspected by Environmental Health Specialists within the Benton County Environmental Health Division, however, the intake of septic permits is performed by permit technicians in the Community Development Department. To apply for septic permits you will bring the permit application to 360 SW Avery Ave., Corvallis, OR 97333 between 9 am and 1 pm. However, if you have questions specifically about septic permits and what type of septic permit to apply for, please contact the Benton County Environmental Health Division at 541-766-6841 or visit their website.

There are many different types of septic permits. The size of your septic system is based on many factors, including the number of bedrooms being served by the septic system and the soils and slopes on the property. All septic permits are applied for using the Septic Application Packet, available under Supporting Documents on the County's sewage disposal webpage.

The following types of building permits typically require a septic permit:

  • New dwelling
  • Replacement dwelling
  • Addition (increasing the number of bedrooms)
  • Remodel (increasing the number of bedrooms)
  • Commercial (new and capacity additions/alterations)

When building a new dwelling, replacing a dwelling, or adding bedrooms to a dwelling or accessory structure you will also need to complete the Septic Application Packet and submit it along with your building permit(s). Note: The property owner must sign the septic application packet.