HomeMy WebLinkAboutOWTS 5-28-14HEPWORTH-PAWLAK GEOTECHNICAL
May 28, 2014
Pitkin Iron
Attn: Rob Delaney
P.O. Box 1298
Glenwood Springs, Colorado 81602
(rob(pitkiniron.com)
Herwonh•r awlak Geotechnical, 1tic.
5020 County Road 154
Glenwood Springs, Colorado 81601
Phone: 970-945-7988
Fax, 970-945-8454
email: hpgeo@hpgeotech.onN
'' 219 11111+1
RFIELD WAN
NOM i TEWBRONSIfi
Job No. 114 080A
Subject: As -Built Evaluation of On-site Wastewater Treatment System, Pitkin Iron
Septic System, Lot 4, Coke Ovens Exemption, 0755 Airport Road,
Glenwood Springs, Colorado
Dear Mr. Delaney:
As requested by Ed Walters, Hepworth-Pawlak Geotechnical, Inc. has observed the
installation of the Onsite Wastewater Treatment System (OWTS) for the existing
commercial building on the project site. The OWTS components observed include:
effluent pipe, infiltrator chambers, inspection ports, and the locations of the observed
components. We previously designed an OWTS for the subject site and presented our
recommendations in a report dated April 30, 2014, Job No. 114 080A. Our observations
and recommendations are presented in the following paragraphs.
We performed our As -Built site evaluation on May 27, 2014. At the time of our site visit
the contractor had excavated an approximate 4 foot wide trench and installed schedule 40
4" pvc pipe from the existing septic tank to the infiltrator units in the septic disposal field.
A single line of fourteen Quick4 Plus infiltrator chambers was installed in the disposal
area trench. An inspection port consisting of a vertical 4" schedule 40 pvc pipe with cap
rising above the finished ground surface was installed in a knockout on each of the end
infiltrator units. The infiltrator units and effluent pipe were installed at a depth of
approximately 48" to 54" below the top of the trench. Maximum depth of soil cover in
our report for the infiltrator units was 36". The discrepancy in cover depth is assumed to
be due to grade limitations in connection with utilizing the existing septic tank.
Measurement with a 4 foot construction level at two locations along the effluent pipe
indicated positive drainage from the septic tank toward the infiltrator units. The
components noted above were observed to be located generally as shown on the attached
OWTS As -Built Site Plan.
It is our opinion that the installed OWTS meets the general intent of our April 30, 2014
design report (except for the infiltrator unit soil cover depth as discussed above and
should perform as intended by the design). The OWTS As -Built Site Plan is shown on
the attached Figure 1. An As -Built Photo Log is also provided as an attachment.
Parker 303-841-7119 • Colorado Springs 719-633-5562 • Silvcrthorne 970-468-1989
Pitkin Iron
May 28, 2014
Page 2
The observations and recommendations presented above are based on our site
observations and our experience in the area. We make no warranty either express or
implied. Alterations to the system including recommended corrections, backfill and site
grading could alter the operation and effectiveness of the OWTS. On-site observations of
the OWTS backfill, recommended corrections or other out of scope services can be
provided for an additional cost.
Please feel free to contact us if you have any questions regarding this letter.
Sincerely,
HEPWORTH - PAWLAK GEOTECHNICAL, INC.
James A. Parker, P.E., P.G.
Rev. by:
Steven L. Pawlak, P.E.
Attachments: Figure 1 — OWTS As -Built Site Plan
As -Built Photo Log
Job No. 114 080A
Gtech
AIRPORT ROAD
PRESS
ro
a
176.4.
EXISTING BUILDING
ROLLER
r
SOIL TREATMENT AREA
CONSISTING OF ONE ROW OF
NT. 14 INFILTRATOR QUICK 4 PLUS
I CHAMBERS
LJ
120.4'
ROLLER
EXISTING 1,000 GALLON,
TWO CHAMBER
CONCRETE SEPTIC TANK
(ASSUMED)
H -P GEOTECH RECOMMENDS THAT THE
SOIL TREATMENT AREA AND SEPTIC
TANK BE PROTECTED FROM POTENTIAL
DAMAGE BY VEHICULAR TRAFFIC BY
MEANS OF BOLLARDS OR FENCING
APPROXIMATE SCALE:
1 INCH = 40 FEET
114 080A
Gtech
HEPWORTH•PAWLAK GEOTECHNICAL
LOT 4, COKE OVENS EXEMPTION
OWTS AS -BUILT SITE PLAN
FIGURE 1
PHOTO
LOG
114 080A
Gtech
HEPWORTH-PAWLAK GEOTECHNICAL
LOT 4, COKE OVENS EXEMPTION
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