HomeMy WebLinkAboutOWTS Installation Observations 03.25.202133 Four Wheel Drive Road
Carbondale, CO 81623
970.309.5259
carla.ostberg@gmail.com
March 25, 2021 Project No. C1530
Daniel Bucio
mdconstructionllc14@gmail.com
Onsite Wastewater Treatment System (OWTS) Installation Observations
TBD Lafrenz Lane
Garfield County, Colorado
Permit Number SEPT-06-20-6353
Daniel,
CBO Inc. observed the installation of the onsite wastewater treatment system (OWTS) on March 24, 2021
for the subject property. Western Colorado Excavating installed the system.
The OWTS design is based on 5-bedrooms. An average daily wastewater flow of 600 GPD was used.
We verified setback distances to both the well on the property and the neighboring well both wells are
greater than 50-feet from the septic tank and greater than 100-feet from the soil treatment area (STA).
A 4-inch diameter SDR-35 sewer line exits the residence with a double-sweep clean out and a minimum
2% grade to the septic tank.
The system installation included a 1500-gallon, two-compartment Valley Precast concrete septic tank
with an effluent filter on the outlet tee. This filter must be cleaned annually, or as needed. Risers
bring the manhole lids to grade for access.
Effluent gravity flows to a distribution box, and then to five gravelless chamber trenches. Risers were
being added to the distribution box so it will be accessible from grade, and flow equalizers were being
installed on each outlet pipe in the distribution box to assure equal flow to each trench.
Each trench consists of 20 ‘Quick 4’ Low Profile Infiltrator® chambers for a total of 1200 square feet of
infiltrative area. There was at least 4-feet of undisturbed soil between each trench. Installation of both
the distribution box and trenches were slightly deeper than anticipated, but still met the minimum 4-feet
maximum burial depth. Inspection ports must be 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 of the expertise of the installer, soil
type, and weather conditions.
Please call with questions.
Sincerely,
CBO Inc.
Carla Ostberg, MPH, REHS
Boring hole in foundation for sewer line inlet tee to septic tank
Outlet tee with effluent filter (need to add handle extension)
Distribution box
Chamber trenches / piping to each trench well bedded with gravel
Inspection ports at beginning and end of each trench
Well on east side of residence.
832‐R‐13‐002