HomeMy WebLinkAboutEngineer's Design Report 09.23.2014FILL
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PO Box 2844
Glenwood Springs, CO 81602
Ph 970-618-5033
Fax 303-216-2796
September 23rd 2014
Ryan Ivy
717 County Road 120
Glenwood Springs, CO 81601
Subsurface Investigation and Onsite Wastewater System Design, Proposed 5 -bedroom Residence
Lot 2, The Ranch at Coulter Creek
Garfield County, Colorado
Mr. Ivy,
ALL SERVICE septic, LLC performed a subsurface investigation and a revised onsite wastewater
system (OWS) design for the subject residence. The property is located outside of Carbondale
Colorado, in an area where OWS and wells are necessary.
SITE CONDITIONS
A single-family residence, and a garage are proposed, as indicated on Figure 1. A total of 5 -bedrooms
are proposed. The proposed drain field slopes 10% to the east, and vegetation consists of a full cover
of native grasses. A water tap is available to serve water to the residence, although if water will be
provided by an onsite well it must be located greater than 128 feet from the proposed drain field.
SUBSURFACE
The subsurface was investigated by digging three percolation holes, as indicated. The materials
encountered in the percolation holes consisted of clayey sand to the maximum depth explored of 4 feet.
Groundwater or bedrock was not encountered. An eight -foot profile hole must be dug to confirm
subsurface conditions prior to construction of drain field. Percolation rates ranged from 20 to 27
minutes per inch (MPI). A 25 MPI rate will be used to design the OWS.
DESIGN SPECIFICATIONS
The OWS design is based on 5 -bedrooms and an average sewage load of 600 GPD. The installation
must include a 2000 (min) gallon, two-compartment concrete septic tank with an effluent filter. Tank
alternatives may be considered. Four gravelless chamber trenches, using `Quick -4' InfiltratorTM
chambers, must be installed as indicated. Each trench must have I row of 15 chambers, for a total of
60 chambers, equaling 720 square feet (SF) of infiltrative area. Serial distribution must be used to
distribute effluent. Construction must be according to the county ISDS regulations, the septic permit
provided by Garfield County Environmental Health Department, and this design.
Subsurface Investigation and Revised OWS Design
Lot 2, Coulter Creek
Page 2
OPERATION INFORMATION AND MAINTENANCE
The surface of the drain field should be seeded upon completion. Vegetation is an important factor in
drain field performance. Erosion control should be practiced prior to and during re -vegetation. Geo -
fabrics or plastics should not be used over the drain field, No heavy equipment, machinery, or
materials should be placed on backfilled drain field. Livestock should not graze on the drain field.
Plumbing fixtures should be checked to ensure that no additional water is being discharged to OWS.
For Example, a running toilet or leaky faucet can discharge hundreds of gallons of water a day and
harm a drain field.
The homeowner should pump the septic tank every two years and clean the effluent filter as needed.
Garbage disposal use should be minimized, and non -biodegradable materials should not be placed
into the OWS. Grease should not be placed in household drains. Loading from a water softener
should not be discharged into the OWS. No hazardous wastes should be directed into the OWS.
Mechanical room drains should not discharge into the OWS. The OWS is engineered for domestic
waste only.
ADDITIONAL CONSTRUCTION NOTES
If design includes a pump, air release valves and weep holes should be installed to allow pump lines
to drain to minimize risk of freezing. Excavation equipment must not drive in excavation of drain
field due to the potential to compact soil. Extensions should be placed on all septic tank components
to allow access to them from existing grade. Precast concrete tanks and distribution boxes should be
used, unless plastic or fiberglass is required. Access to all tank compartments and distribution devices
is optimal.
INSTALLATION OBSERVATIONS
ALL SERVICE septic, LLC, and the county must view the OWS during construction. The OWS
observation should be performed before backfill, after placement of chambers and distribution pipes.
Septic tanks, distribution devices, pumps, dosing siphons, and other plumbing, as applicable, must
also be observed. ALL SERVICE septic, LLC should be notified 48 hours in advance to observe the
installation.
Subsurface Investigation and Revised OWS Design
Lot 2, Coulter Creek
Page 3
LIMITS:
The design is based on information submitted. If soil conditions encountered are different from
conditions described in report, ALL SERVICE septic, LLC should be notified. All OWS construction
must be according to the county regulations. Requirements not specified in this report must follow
county regulations. The installer should have documented and demonstrated knowledge of the
requirements and regulations of the county in which they are working.
Please call with questions.
Sincerely,
ALL SERVICE septic, LLC
Timothy R. Petz
3 copies
Reviewed By:
Richard H. Petr,