HomeMy WebLinkAboutOWTS Installation Observations 01.22.15
January 22, 2015 Project No. C1072
Larry Singer
lssinger@comcast.net
Onsite Wastewater Treatment System (OWTS) Installation Observations
2621 CR 100
Garfield County, Colorado
Garfield County Permit No. SEPT-8-14-3344
Larry,
ALL SERVICE septic, LLC observed the installation of the onsite wastewater treatment system (OWTS)
on December 1st and 4th, 2014 for the subject property. PifCo installed the system.
The OWTS will serve a 5-bedroom main residence, 1-bedroom cabin, and a future RV parking
structure with plumbing to be used by residents of the property. The existing OWTSs serving the
main residence (septic tank and soil treatment area) and cabin (cesspool) were properly abandoned.
The new OWTS installation included a new Valley Precast 1500-gallon, three-compartment septic
tank (specifications enclosed). This variation from the original design was approved by Andy
Schwaller with Garfield County Community Development Department.
“Dead men” were installed under the septic tank to avoid floating of the tank during high seasonal
groundwater. We recommend the septic tank NOT be pumped during high groundwater
conditions. At the time of our installation observations, only the cables were visible. Additionally,
backfill around the septic tank appeared to have some large rocks. We recommended the installer
remove the larger rocks and replace with smaller diameter material for backfill.
The Orenco® duplexing pumping system was installed in the third compartment of the septic tank
and pump start up performed by Valley Precast. There is an effluent filter in this compartment
that must be cleaned annually, or as needed. The control panel is located within line of sight of
the septic tank, mounted on the outside wall of the residence. On January 20, 2015, we reviewed the
operation of the OWTS and demonstrated how to remove and clean the filter in the septic tank.
Effluent is pumped through a 1.5-inch diameter pump line to the mound. The minimum separation of
4-feet between the infiltrative area and high seasonal groundwater was maintained. The mound
consisted of a 15’ x 56’ footprint of concrete sand, 2-feet deep. The 1.5-inch diameter laterals with
1/8-inch orifice holes (facing down) spaced 3-feet on center were placed on gravel and geofabric
was used to cover the distribution laterals. Inspection ports were installed on opposite corners of the
sand filter.
The OWTS was generally installed according to specifications. This observation is not a guarantee of
workmanship and/or parts and materials. ALL SERVICE septic, LLC should be notified if changes are
made to the OW TS 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,
ALL SERVICE septic, LLC Reviewed By:
Carla Ostberg, MPH, REHS Richard H. Petz, P.E.
Clean out and 4-inch sewer pipe from house to septic tank
4-inch sewer pipe from cabin to septic tank control panel for pump
Control panel
View of septic tank and risers
Inlet tee (first compartment) Pump chamber and effluent filter (third compartment)
Note cable holding
dead men
Note larger cobbles –
recommended smaller
diameter backfill
material
Pump line from septic tank to mound (second pipe is electrical conduit)
Mound prepared for sand filter material
Distribution laterals on sand and gravel
gravel
sand
Sand filter material Laterals with orifice holes
Geofabric over laterals.
Missing caps on observation pipes on mound (Jan. 20, 2015)
Inspection port
Pump Selection for a Pressurized System - Single Family Residence Project
Singer Residence / Project C1072
Parameters
Discharge Assembly Size
Transport Length
Transport Pipe Class
Transport Line Size
Distributing Valve Model
Max Elevation Lift
Manifold Length
Manifold Pipe Class
Manifold Pipe Size
Number of Laterals per Cell
Lateral Length
Lateral Pipe Class
Lateral Pipe Size
Orifice Size
Orifice Spacing
Residual Head
Flow Meter
'Add-on' Friction Losses
1.25
220
40
1.50
None
6
9
40
1.50
3
47
40
1.50
1/8
3
5
None
0
inches
feet
inches
feet
feet
inches
feet
inches
inches
feet
feet
inches
feet
Calculations
Minimum Flow Rate per Orifice
Number of Orifices per Zone
Total Flow Rate per Zone
Number of Laterals per Zone
% Flow Differential 1st/Last Orifice
Transport Velocity
0.43
48
20.8
3
0.5
3.3
gpm
gpm
%
fps
Frictional Head Losses
Loss through Discharge
Loss in Transport
Loss through Valve
Loss in Manifold
Loss in Laterals
Loss through Flowmeter
'Add-on' Friction Losses
3.0
5.8
0.0
0.1
0.1
0.0
0.0
feet
feet
feet
feet
feet
feet
feet
Pipe Volumes
Vol of Transport Line
Vol of Manifold
Vol of Laterals per Zone
Total Volume
23.3
0.9
14.9
39.1
gals
gals
gals
gals
Minimum Pump Requirements
Design Flow Rate
Total Dynamic Head
20.8
20.0
gpm
feet
0 5 10 15 20 25 30 35 40 0
50
100
150
200
250
300
Net Discharge (gpm)
PumpData
PF3005 High Head Effluent Pump
30 GPM, 1/2HP
115/230V 1Ø 60Hz, 200V 3Ø 60Hz
PF3007 High Head Effluent Pump
30 GPM, 3/4HP
230V 1Ø 60Hz, 200/460V 3Ø 60Hz
PF3010 High Head Effluent Pump
30 GPM, 1HP
230V 1Ø 60Hz, 200/460V 3Ø 60Hz
PF3015 High Head Effluent Pump
30 GPM, 1-1/2HP
230V 1Ø 60Hz, 200/230/460V 3Ø 60Hz
Legend
System Curve:
Pump Curve:
Pump Optimal Range:
Operating Point:
Design Point:
832‐R‐13‐002