HomeMy WebLinkAboutOWTS Installation Observations 05.16.202033 Four Wheel Drive Road
Carbondale, CO 81623
970.309.5259
carla.ostberg@gmail.com
May 16, 2020 Project No. C1520
Tyko Isaacson
Tyko.isaacson@usda.gov
Onsite Wastewater Treatment System (OWTS) Installation Observations
312 Hwy 325
Garfield County, Colorado
Permit Number SEPT-6239
Tyko,
CBO Inc. observed the installation of the onsite wastewater treatment system (OWTS) on May 4, 2020 for
the subject property. Sacred Ground Excavation installed the system.
The existing septic tank was pumped and crushed, and the remaining void filled with onsite materials.
The new OWTS design is based on 3-bedrooms. An average daily wastewater flow of 450 GPD was
used.
A new, 4-inch diameter SDR-35 sewer line was installed as the existing cast iron sewer line exits the
residence. The sewer line had a double-sweep clean out and a minimum 2% grade to the septic tank.
The system installation included a 1000-gallon, two-compartment poly Norwesco® septic tank with an
effluent filter on the outlet tee. This filter must be cleaned annually, or as needed.
The sewer line to the distribution box was plumbed under a shallow irrigation ditch encased in concrete.
The sewer line was encased in 6-inch diameter Schedule 40 sewer line 10-feet on each side of the ditch.
Effluent gravity flows to a distribution box, and then to two gravelless chamber beds. The distribution box
was accessible from grade and flow equalizers were installed.
Each bed consists of 4 rows of 11 ‘ARC’ ADS Low Profile chambers for a total of 88 chambers and 1320
square feet. There was at least 6-feet of undisturbed soil between each bed. Inspection ports were
installed at each corner of each bed. Ports may be cut to grade and placed in sprinkler boxes for access.
The area of the STA in the pasture should be fenced off to protect it from any large livestock traffic.
We verified the distance to the open section of ditch to the east as greater than 50-feet. The ditch to the
east had been turned on since our last visit to the property. Some over-flow was noted just above and to
the east of the STA. After our inspection, Sacred Ground Excavation worked with the ditch company to
stop flow. If flow west of the STA resumes at any time, a culvert must be constructed to divert any over-
flow of the ditch around and to the south of the STA.
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.
5/30-2020
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.
Slats looking into wooden septic tank cast iron pipe
Boards removed from top of tank looking toward Rifle Creek
New sewer line connected to existing cast with Fernco new Norwesco septic tank
Inlet tee Effluent filter
Sewer line from septic tank to distribution box / encasement pipe under concrete ditch
Distribution box
Chamber beds (4 rows of 11 ARC ADS chambers each row)
Overflow from ditch to the west / flow stopped
If flow resumes, culvert must be installed to route any over-flow to the south of the STA
832‐R‐13‐002