HomeMy WebLinkAbout1629 design Jack rabbit.doc
August 4, 2009 Project No. 1629
Phil Vaughan Construction Management
At: Phil
1038 County Road 323
Rifle, CO 81650
Subsurface Investigation and Onsite Wastewater System Design, Jackrabbit Compressor Station
Garden Gulch Road
Garfield County, Colorado
Phil,
ALL SERVICE septic, LLC performed a subsurface investigation and an onsite wastewater system (OWS) design for the subject residence. The property is located 12 miles along Garden Gulch
Road, outside of Parachute, in an area where OWS are necessary.
SITE CONDITIONS
A compressor station is being constructed. An office building is proposed next to the compressor station, which will accommodate 4 persons per day for an 8 to 12 hour shift. A large
‘pad’ has been constructed from fill on which the compressor station and office will be built. The proposed drain field area is relatively flat, and there is no vegetation.
SUBSURFACE
The subsurface was investigated by digging one profile pit and three percolation holes, as indicated. The materials encountered in the profile pit consisted of 8 feet of compacted sandy
gravelly fill. Groundwater or bedrock was not encountered. Three percolation holes were dug, in the area of the proposed drain field, as indicated. Percolation rates ranged from 10
to 20 minutes per inch (MPI). Based on the drain field being constructed with imported sand filter material, a 28 MPI rate will be used to design the OWS.
DESIGN SPECIFICATIONS
The OWS design is based on 4 office persons per day and an average sewage load of 100 GPD. The installation must include a 1000-gallon, two-compartment, precast concrete septic tank,
with an effluent filter on the outlet, to be followed by a gravelless chamber drain field with 2 feet of imported sand filter material (ASTM C-33 concrete sand). One gravelless chamber
bed, using ‘Quick-4’ Infiltrator™ chambers, must be installed as indicated. The bed must have 3 rows of 6 chambers, for a total of 18 chambers, equaling 178 square feet (SF) of infiltrative
area. A 4-inch level manifold must distribute effluent.
Construction must be according to the Garfield County Environmental Health Department OWS regulations, the OWS Construction Permit provided by the county, and this design. This design
for the subject property, noted above, is valid only in conjunction with the approved Garfield County Environmental Health Department.
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.
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 Reviewed By:
Timothy R. Petz Richard H. Petz, P.E.
3 copies
Onsite Wastewater Systems
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