HomeMy WebLinkAboutOWTS Installation Observations 07.20.2026CBO Inc.
129 Cains Lane
Carbondale, CO 81623
970.309.5259
carla.ostberg@gmail.com
July 20, 2026 Project No. C1997
Terry Hale
thale@broadbrookrealty.com
Onsite Wastewater Treatment System (OWTS) Installation Observations
5810 CR 320
Garfield County, Colorado
OWTS Permit SEPT-9710
Terry,
CBO Inc. observed the installation of the onsite wastewater treatment system (OWTS) on June 30, 2026
for the subject property. Energy Field Services (Ken White) installed the system.
The site plan enclosed is not the result of a survey. We used hand sketches, Google Earth Images, and
other resources available to us. We created the enclosed site plan to the best of our ability.
The OWTS design is based on 4-bedrooms. An average daily wastewater flow of 525 GPD was used.
The existing septic tank was abandoned by pumping the tank and removing it. The existing soil
treatment area (STA) was abandoned in place.
The 4-inch SDR-35 sewer line exiting the residence had a double-sweep clean out and a minimum 2%
grade to the septic tank.
The system installation included a 1500-gallon, two-compartment Norwesco® poly septic tank with an
Orenco® Biotube effluent filter on the outlet tee. This filter must be cleaned annually, or as needed.
Risers must bring the manhole lids to grade for access.
Effluent gravity flows to a distribution box, and then to four gravelless chamber trenches. The distribution
box was accessible from grade with flow equalizers installed on each outlet pipe in the distribution box to
assure equal flow to each trench.
Each trench consists of 11 ‘ADS’ ARC 36 chambers for a total of 44 chambers and 660 square feet of
infiltrative area. There was at least 4-feet of undisturbed soil between each trench. Inspection ports
were installed at the beginning and end of each trench. Ports may be cut to grade and placed in sprinkler
boxes for access.
The OWTS was generally installed according to specifications. This observation is not a guarantee of
workmanship and/or parts and materials. CBO Inc. should be notified if changes are made to the OWTS
in the future. Any additional OWTS construction must be according to the county regulations.
LIMITS: Observations are limited to components that are visible at the time of the inspection. The installer must
have documented and demonstrated knowledge of the requirements and regulations of the county in
which they are working. The quality of the installation is dependent on the expertise of the installer, soil
type, and weather conditions.
Please call with questions.
Sincerely,
CBO Inc.
Carla Ostberg, MPH, REHS
Trenches installed with inspection ports at beginning and end of each trench
View of septic tank and clean out Clean out to septic tank
Existing septic tank removed Clean out (exited the foundation deeper than recommended)
View of septic tank looking towards STA / Distribution box
Recommend angle on inlet pipe in dbox ARC 36 chambers
Trenches installed
Inlet tee Effluent filter
832‐R‐13‐002