Before applying for a new septic system, it is necessary to have a valid soils testing (On Site Soils Evaluation - OSSE) done.

An OSSE includes soil tests that determine the effectiveness of soil to filter sewage through leach lines, as well as observations of required setbacks, constraints and possibilities for an individual, “on-site” septic system. The report produced by the consultant of the particular site tested on a parcel is reviewed and evaluated by an Environmental Health Specialist who generates a findings report.

An OSSE must be conducted by a Nevada County approved Soil Testing Consultant. Reports are valid if completed after 1998, with a possibility of extending back to 1991 pending Consultant re-certification. 

It is recommended to have the consultant apply for the OSSE permit, as well as schedule insections to conduct the OSSE. This can be done by calling the number below under OSSE Scheduling. Once the permit is issued and you have completed your final inspection, you can proceed to apply for a Septic Permit Application. 


  1. Hire a Nevada County Approved Soils Testing Consultant
  2. Apply Online (Note: You will need  your Consultants contact information to apply online)
  3. Consultant schedules an OSSE (see below)
  4. Consultant and Nevada County Specialist meet on site for soils testing
  5. Consultant submits Soils Evaluation Report to Nevada County
  6. Nevada County Specialist generates Findings Report to approve what type of septic system to install
  7. You may then proceed to apply for a Septic Permit (see above tab)

Scheduling an OSSE

Updated: January 15, 2019

We are now scheduling OSSE's for the week of Jan 22nd - 25th

Please Note: The County will try to accommodate requested dates but cannot guarantee availability.  

To schedule an OSSE, please call (530)265-1599.