As of June 4, 2018 all applications for a new on-site wastewater treatment system must include an inspection of two test pits as part of the site and soil evaluation. Results of percolation tests may also be submitted, but must be done in conjunction with the evaluation of two test pits. The test pits must remain open for inspection by Larimer County, and can be inspected prior to permit application using this form.

A separate site evaluation and fee is only required if construction of the test pits will occur prior to applying for a permit, and the test pits must be backfilled immediately. Otherwise, the test pits may be secured by using fencing, staking a line around the perimeter, or other effective methods, and will be evaluated by Larimer County at the time of permit application. No additional fee for a site evaluation is required if test pits are left open for inspection after permit application.   

After submitting an application for a site evaluation, arrangements will need to be made to schedule inspection of the test pits. Please allow a minimum of 5 business days for scheduling the inspection.

Soil test pits must be constructed per the following guidelines (link to our Site & Soil page);

  • A minimum of two test pits in the area of the proposed soil treatment area. Generally, two pits set 40-50 feet apart in the proposed area is suitable.
  • The test pits must be dug to a depth of eight feet, or less if groundwater or bedrock is encountered before eight feet. The hole should be benched at a depth of four feet below grade and sloped back to the surface at 45 degrees to allow for entry to the benched portion.
  • The test pits must remain open for inspection by Larimer County and the soils engineer or system designer.

Site Evaluation Form