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1 • The installer shall not place fill in the open excavation until inspected and approved by the
design engineer. Additionally, the final cover shall not be placed on sewer lines, septic tank,
' or the absorption area until the system has been inspected and approved by the design
engineer. The installer shall provide 48 hour notice to the engineer for all required
inspections.
1 • The effluent distribution system shall be constructed in accordance with the "Infiltrator
Technical Manual" available from Infiltrator Systems Inc., 123 Elm Street, Suite 12, Old
Saybrook, Connecticut 06475.
• A non - corrodible filter shall be installed at the final outlet Tee of the septic tank or in the
' effluent line between the septic tank and the absorption field to limit the size of solids and
sludge passing into the absorption field. The filter must be accessible for cleaning and
replacement from the ground surface.
1 • The distribution boxes shall be set level on undisturbed native soil or a structural pad (e.g.,
compacted fill or concrete) to prevent settling and promote uniform distribution of flow to the
absorption field. A 45 degree bend shall be turned down on the septic influent line to damp
surge flows from the septic tank and promote equal distribution.
• The surface cap shall consist of native soil mounded 5% over the absorption field to promote
1 surface runoff. Backsloping of the surface cap from the cap perimeter elevation to the
existing ground surface shall consist using native soil to maintain a maximum slope of 3/1
(33 %) to the existing ground surface to minimize erosion. The existing ground surface under
1 the basal extent of the soil cap shall be disked or scarified to enhance subsurface absorption.
• The system contractor shall be aware of the potential for construction activities to reduce soil
' permeabilities at the site through compaction, smearing, and shearing. The following
precautions and construction procedures should be employed during installation to minimize
disturbance to native soils:
Excavation should proceed only when the moisture content of the soil is below the
plastic limit. If a sample of soil forms a rope instead of crumbling when rolled
between the hands it is too wet and should be allowed to dry before excavation
continues.
ii. Excavation and backfiill equipment should work from the surface where at all
' practical to avoid compaction of the soils at depth.
The bottom and sidewalls of the excavation should be left with a rough, open
surface. The appearance should be that of broken or ripped soil as opposed to a
sheared, smeared, or troweled surface. Any smoothed or smeared surfaces should be
removed with a toothed rake or shallow ripper taking care to remove loose residues
from the bottom of the excavation by hand if necessary.
iv. Care should be taken in placing fill materials in the excavation to avoid damaging the
exposed soil surfaces.
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1 CRONK
1128 •24• Road
CONSTRUCTION • Grand Junction, CO 81505
INCORPORATED 970-245-0577, 970-257-7453 (fax)
1
sons AND PERCOLATION REPORT
1 Date: October 4, 2001
1 Prepared by: Thomas A. Cronlc, P.E.
1129 -24- Road
Grand Junction, CO 81505
1 245 -0577
Client: Todd Leahy
1 1015 Bennett
Glenwood Springs, CO 81601
(970) 618 -0756/945 -2244
1 Property address: FDR 300, Glenwood Springs, CO
Tax schedule No.:
1 Legal Descript.:
1.0 Soils Evaluation
The site consists of approximately 2 acres of uncultivated native soil. Drainage is approximately 5% to the
1 northeast in the area of reference. A percolation test/soils evaluation was conducted on the property of
reference on 10/04/01 by Tom A. Cronk, registered professional engineer (R.P.E.).
1 The soils observation excavation was extended to a depth of 96" below ground surface (BGS). There was no
evidence of ground water or high seasonal water table in the open excavation to a depth of 96" BGS. The soils
evaluation indicates one distinct soils horizon underlies the site. A Iithological description follows:
1 depth (in.) description
1 0" - 96" silty clay, gray to blackish gray; hard and blocky; some brown to light brown silty
sand
1 Perc holes were constructed at depths of approximately 60 in. and 72 in. The holes appeared to be well
saturated at the time of the test. Results of the percolation test are shown in Table 1.
TABLE 1
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Percolation Teel Results
FDR 300, Glenwood Springs
'
Depth Timeoo 10/04/01 Zion Perc
Drop Rate
16:36 17:10 17:36 min/in
' (A) 72' - 84" 3.125 4.5 5.625 60/2.5 24
(3) 60" - 72" 4.25 4.875 5.375 60/1.125 53
' (C) 72" • 84 6.0 8.0 8.75 _ _ 60/2.75 _ 22
2.0 Conclusions and Recommendations
1 Soils at the site appear acceptable for implementation of an individual sewage disposal system (ISDS). The
following site - specific considerations should be observed during implementation of the 1SDS:
• The bottom of the ISDS absorption field should be located no deeper than 48" DOS to
maintain 4' of usable infiltration soil above the extent of the soils observation excavation
located at 96" BGS. An average design Perc rate of 40 min/in. is recommended for overall
' system sizing.
• Care should be taken during construction to avoid compaction and smearing of the exposed
infiltrative surfaces and preserve the natural permeability of the native soils.
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