Soil Site Evaluation

A soil site evaluation determines if a septic system can be approved on a lot. The test considers all options including standard and sand filter systems. The "cheapest-best" system is always prescripted. If the minimum DEQ rules cannot be met a denial notice will be issued. If approval is granted a separate septic installation permit may be applied for by the property owner.

Site criteria

The suitability of a site for a septic system is largely determined by the type and depth of soil and the depth to the water table. Other factors include the size of the property, the slope, location of the system relative to streams, wells, cuts and fills, and whether sewer service is available.

Application process

The following must be submitted to the Septic and Onsite Wastewater program at the time of application:

  1. The application form must be filled out completely and signed by the property owner. Multiple lots will require an application for each lot.
  2. An acceptable plot plan (per example).
  3. Fee of $835 for each lot.

Note: An Entrance Permit may be required to construct an access point to the property. Contact Transportation Engineering for more information.

To ensure the quickest and most accurate possible analysis of your site please pay special attention to the following guidelines. Sites that do not adhere to the following risk denial or an extended review time.

Test pits

View Test Pit Preparation for Onsite Sewage Evaluations

  1. Provide a minimum of two test pits (maximum of six).
  2. Test pits must be dug per Test Pit Preparation guide.
  3. Keep the "spoils" pile at least two feet away from the edge of the test pit.
  4. Test pits should be spaced 100' apart in the area where you intend to locate the original and replacement drainfields.
  5. Locate the test pits in an area no smaller than 100' x 100' and no larger than five acres.
  6. Test pits should be located on the driest part of the property and should not be located within any of the setbacks. (see setback list)
  7. Test pits must be dug when you apply. Failure to have test pits dug when our inspector visits the site will result in your project being delayed

Site preparation

  1. If the test pits are not easy to find, mark a trail to them in the field
  2. Identify the property corners on site using clearly marked stakes or similar means.
  3. Post yellow permit card at the public end of your driveway or access road.


The owner will be notified by mail. Due to staffing concerns and a high volume of applications the Soil Site Evaluation may take several weeks to complete. Unfortunately it is not possible to schedule on-site visits at this time. Please contact us at 503-742-4740 or email for additional questions.


Development Services Building 150 Beavercreek Road 2nd floor Oregon City, OR 97…

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Monday - Thursday
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