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Natallia Kharkal
21050 NE 38t'Avenue,
Apt. 1804
Aventura, Florida 33 1 80
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Project No. 21-7-761
Subject:Observation of Garage Excavations, Proposed Duplex Residence, Lot D-34,
Aspen Glen,65 Upland, Garfield County, Colorado
Dear Natallia:
As requested, a representative of Kumar & Associates, Inc. observed the excavation at the
subject site on May 14,2024 to evaluate the soils exposed for foundation supporl. The findings
of our observations and recommendations for the foundation design are presented in this report.
We previously conducted a subsoil study for design of foundations at the site, report dated
October lg,21z|,Project No.2I-7-761 and observed the basement excavation, report dated
July 25, 2022, Project No. 21-7-76i.A'
At the time of our visit to the site, the concrete basement footings and foundation walls were
in place and had not been backfilled. The perimeter drain system had not been installed. The
irrigation ditch on the northwest side of the property was running water. The northwestern
comer of the basement is about 10 feet away from this ditch. No water was observed adjacent
to the nearby basement footing arca atthe time of our site visit although some seepage had been
noted in this area about 10 days earlier. The foundation footings for the garage areas had not
been constructed.
The soils exposed in the foundation excavation for the basement footings consisted of relatively
dense slightly silty sand and gravel with cobbles. The excavation for the garage areas had been
partially excavated to about 2 to 3 feet below original site grade. The soils exposed in the garage
areas consisted of stiff sand silty clay. No free water was encountered in the excavation and the
soils were slightly moist to moist.
The soil conditions exposed in the excavation are consistent with those previousiy encountered
on the site. The basement foundation walls have been in place for some time and the top of
wall elevations should be checked prior to framing the house walls. The clay soils in the garage
areas should be removed below footing grade (if needed) and the garage footings should be
placed entirely on the underlying dense gravel soils as previously recommended. Foundations
placed on the gravel soils should be suitable for support of spread footings designed for the
recommended allowable bearing pressure of 3,000 psf, Loose and disturbed soils should be
removed in the footing areas to expose the undisturbed natural gravel soiis. Other
recommendations presented in our previous report which are applicable should also be observed.
Natallia Kharkal
};day 15,2424
Page2
The water seepage from the nearby irrigation ditch is apparently intermittent and flows into the
excavation appear to be less than lgpm. A properly installed perimeter drain system should be
capable of controlling the intermittent water seepage. Since the site is relatively flat, we assume
that the perimeter drain system will be sloped atYzto 1 percent grade and routed to a drywell
outside the building area. A drywell based in the gravel soils at this site should be capable of
handling these intermittent flows. The drywell should be accessible from the ground surface
for inspection and in case a pump needs to be installed later'
The recommendations submitted in this letter are based on our observation of the soils exposed
within the foundation excavation and the previous subsurface exploration at the site. Variations
in the subsurface conditions below the excavation could increase the risk of foundation
movement. We should be advised of any variations encountered in the excavation conditions
for possible changes to recommendations contained in this letter. Our services do not include
determining the presence, prevention or possibility of mold or other biologieal contaminants
(MOBC) developing in the future. If the client is concerned about MOBC, then a professional
in this special field of practice should be consulted.
If you have any questions or need further assistance, please call our office.
Sincerely,
Kusnan & &ssmc$atesn
Daniel E. Hardin, P
Rev. by: SLP
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