HomeMy WebLinkAboutOWTS Installation Observations 04.21.2025CBO Inc.
129 Cains Lane
Carbondale, CO 81623
970.309.5259
carla.ostberg@gmail.com
April 21, 2025 Project No. C1876
Jenny Vandeventer
Agua.amarga@gmail.com
Onsite Wastewater Treatment System (OWTS) Installation Observations
15 Old Orchard Road
Garfield County, Colorado
Permit SEPT-8825
Jenny,
CBO Inc. observed the installation of the onsite wastewater treatment system (OWTS) on October 16,
2024 for the subject property. RMB Excavation installed the system.
The OWTS design is based on 5-bedrooms. An average daily wastewater flow of 600 GPD was used.
The existing septic tank was abandoned by pumping the tank and crushing the top, bottom, and sides
and filling in the void with onsite materials. The existing soil treatment area (STA) was abandoned in
place.
An irrigation ditch runs to the west of the proposed STA. The ditch was realigned and is greater than The
50-feet from the STA.
The new 4-inch SDR-35 sewer line exiting the residence ties into the existing sewer line. A new double-
sweep clean out was installed on the sewer line and has a minimum 2% grade to the septic tank.
The system installation included a 1500-gallon, two-compartment Infiltrator® poly septic tank with an
Orenco® Biotube effluent filter on the outlet tee. The effluent filter must be cleaned annually, or as
needed.
Effluent gravity flows to a distribution box, and then to six 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 10 ‘Quick 4’ Standard Plus Infiltrator® chambers for a total of 60 chambers and
720 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
Clean out on new sewer line View of sewer line trench from house to septic tank
Existing septic tank being abandoned
Septic tank installed
Effluent filter installed with handle extension
Distribution box
Trenches
Ditch realignment
832‐R‐13‐002