HomeMy WebLinkAboutEngineer's Report - Site Evaluation OWTS 09.07.2011September 7, 20I11
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Glenn Rappaport, AIA, principal
Post Office Box 1847
Basalt, Colorado 81621
RE: Site Evaluation—Onsite Wastewater System (OWS) Evaluation, Existing System Conditions for
Single Family Residence located 704 Skipper Drive on Lot 10, Stirling Ranch PUD in Garfield County,
Colorado.
SE Proposal No. 11145.01 Parcel No. 239129305010
Dear Glenn:
Pursuant to your request, this letter presents our findings in regard to the existing Onsite Wastewater
Systems (OWS) associated with the above referenced Site. It is our understanding that you are currently
applying to Garfield County for a building permit to allow limited remodeling activities inside the home.
Two individual systems are currently in operation to serve the needs of the existing 4 -bedroom home on
the site. The systems were constructed under separate County issued 1SDS permits. We have located and
performed inspections of certain OWS components, reviewed previous permit information and have
observed the existing site conditions. We understand that our initial investigation is to provide an opinion
of the system's adequacy for continued usage to treat sewage from the residence. Our findings and
recommendations are based on our current knowledge of the site conditions with respect to information
provided by others.
Conclusions
In our opinion we believe that the systems appear adequate to serve the needs of the residence in the short
term and that the systems can be utilized without any immediate maintenance required. Evidence of
general tank, field or piping problems or failures was not observed with either systems and typical system
function is expected under average usage. The systems are in general compliance with State and County
standards to accommodate the design flow from the proposed dwelling based on our review of the permit
documents.
Findings
Onsite wastewater system's sewer lines, tanks and cleanout were located and inspected by TV and field
probe methods conducted on August 16, 2011 by Bishop Plumbing and observed by Sopris Engineering.
The located components were surveyed and incorporated into an existing conditions map.
The East system (Permit No. 1580) was constructed in 1987 was inspected by the County. The system
consists of a 1250 gallon 2 -chamber concrete septic tank with a reported 18' by 30' absorption field
installed to serve a two bedroom residence. The reported percolation rate indicated on the permit is 15
minutes per inch. Our TV investigation revealed that the sewer pipes in the house and the single 4" PVC
line out to the tank are in good condition and function as expected. The sludge layer in the primary
compartment of the septic tank is approximately 12" deep and relatively light. The clear zone appears
normal and a limited amount of scum was observed at the liquid level. Approximately 100 gallons of
water was drained into the tank during our investigation and flow patterns suggested adequate operation
502 Main Street • Suite A3 • Carbondale, CO 81623 • (970) 704-0311 • Fax (970) 704-0313
SOPRIS ENGINEERING • LLC
civil consultants
Glenn Rappaport
SE Job No. 11145.01
September 7, 2011
Page 2 of 2
through the lines and tank. The tank is not in need of pumping however both tank chambers should be
inspected within a year or after an extended period of full usage next spring.
The West system (Permit No. 1689) was constructed to accommodate a 2 bedroom addition and was
inspected by the County. The system consists of a 1000 gallon 2 -chamber concrete septic tank with a
reported 24' by 40' absorption field installed to serve a two bedroom residence. The reported
percolation rate indicated on the permit is 15 minutes per inch. Our TV investigation revealed that the
sewer pipes in the house and the single 4" PVC line out to the tank are in good condition and function as
expected. The sludge layer in the primary compartment of the septic tank is approximately 4" deep and
light. The clear zone appears normal and a limited amount of scum was observed at the liquid level.
Approximately 50 gallons of water was drained into the tank during our investigation and flow patterns
suggested normal operation through the lines and tank. The tank is not in need of pumping however both
tank chambers should be inspected within a year or after an extended period of full usage next spring.
Please contact us if you have any questions or concerns.
Sincerely,
SOPRIS ENGINEERING, LLC
28377
ancy Nicho
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