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. C1534
Kurt Carruth
kurt@hinge-architects.com
Onsite Wastewater Treatment System (OWTS) Installation Observations
Metal Shop
160 Gemat Circle
Lot 4, Big R Commercial Park
Garfield County, Colorado
Permit Number SEPT-6490
Kurt,
CBO Inc. observed the installation of the onsite wastewater treatment system (OWTS) on January 26,
2021 for the subject property. Hughes Excavation (Brad Harris) installed the system.
The building will be served potable water from a private well on the property. The well was not drilled at
the time of this report. The well may not come within 50-feet of the proposed septic tank and within
100-feet of the proposed soil treatment area (STA). No OWTS component will come within 25-feet of
the existing water line. The proposed well location is on the east side of the building.
Four employees are anticipated at the Metal Shop. Fixtures include a toilet/lavatory and shop sink. The
OWTS design is based on an average daily wastewater flow of 150 GPD. The OWTS was designed
to handle domestic waste only. Floor drains should be routed to a separate drywell.
The sewer line exiting the shop has a double-sweep clean out and a minimum 2% grade to the septic
tank.
The system installation included a 1000-gallon, two-compartment concrete septic tank with an effluent
filter on the outlet tee. This effluent filter must be cleaned annually, or as needed. Traffic rated risers
bring the cast-iron manhole lids to grade for access.
Effluent gravity flows to a distribution box, and then to two gravelless chamber trenches. An additional
double-sweep clean out was installed on the sewer line leading to the distribution box at approximately
100-feet from the septic tank. The distribution box was accessible from grade and flow equalizers were
installed on each outlet pipe in the distribution box to assure equal flow to each trench.
Each trench consists of 8 ‘ARC’ ADS chambers for a total of 16 chambers and 240 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.
3-31-2021
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. Reviewed By:
Carla Ostberg, MPH, REHS Romeo Baylosis, P.E.
View of septic tank / traffic rated tank, risers, and lids
Clean out between septic tank and building Distribution box being plumbed
Trenches installed
832‐R‐13‐002