HomeMy WebLinkAboutOWTS Design Report 05.07.2024K-CROATT{?.4. Box 4o
Mar.k, CA
g7o. zio.oif z / kttclz*yl alrurA@ourlott&,com
Onsite Wasteweter Treafnrent System Design
M"y 7, ZOZ4
Coleman Proiect
I0I Monument Ridge Road
Parachute, CO 81635
Parcel No. 2407 -202-26-0IA
Prepared By:
K-Cronk Engineering, Inc.
P.O. Box I40
Mack, CO 81525
e70-25A-0572
Site Historv
There is an existing residence on the site that is served by an existing onsite wastewater treatment system
(OWTS) that will remain in use. The owner of the property wishes to construct a new studio accessory
dwelling unit (A.D.U.) to be sened by a separate OWTS. The A.D.U. will be greater than 400 sq. ft.,
therefore the OWTS will be designed to accommodate a two-bedroom minimum residential loading
(Garfield Counfy OWTS Regulations 43.6.A.2-C & Table 6-2, footnote 3).
The site consists of approximately 6.288 acres of uncultivated native soil. Drainage is towards the west. A
percolation tesVsoils &ahation and site study were conducted on the property of reference on November
13, 2009 by Hepworth-Pawlak Geotechnicalo Inc.
This OWTS design has been prepared for the project based on information disclosed by the report
mentioned above.k-Cronk Engineering, Inc. must be contacted to arrange a site visit prior to installation
to conlirm soils lithology. An observation hole within 50' of the nronosed soil treatment area multPe
urovided bv the client to ttre desien engineer for insnection. Should the soils. Iithologv differ
ffi the November ls. 20og {pnort,bv Henworth-Paqlq\ 9,,eotechnilal,Inc.ffi mav be required. A discussionof the engineered OWTS design follows.
alperco1ationtest/soilsevaluationisattachedforreferenceasAppendix
A. The location of the perc excavation trench is shorvn in the Plot Plan included in this report.
Development of Desiqn Parameters
Based on the results from the November 13,2009 perc testlsoils evaluation (Appendix A), a desigt perc
rate of 18 min/in. and corresponding long term acceptance rate (LTAR) of 0.60 are chosen for overall
system sizing for an infiltratoi trench soil treatrnent area designed to discharge to subsoils below the 36"
depth.
1
System Desisn
An INFILTRAIOTR trench soil treatment system is proposed for discharge of septic effluent at the site.
Construction of the system will consist of excavating level trenches in the soil treatnent area. $gg{!4g
durins construction mav affect slope. therefore contractor shall verifv slope at time of installation.
Sioil treatment area orientation mav be adiusted ner site vqriations to fac4itatq consistent treFch
ffil contours. Each trench excavation shall be continued to a level depth of
@ of the trench (see Soil Treatment Area Cross Section). If consistent trench depth
cannot be maintained.lNFlIIftlIOX chambers may be installed level at 24" minimum and 48" maximum
BGS. After removal of surface soils, the open excavations will be disked or scarified to promote subsurface
absorption.
Following completion of the trench excavations, QUICK4 STANDAfuD INFILTRATORS (or equivalent)
will be uod to ionstruct a septic effluent distribution system in the open excavations. The INFILTRATOR
effluent distribution system will be installed in accordance with the "Infiltrator Tecbnical Manual",
available from Infiltrator Systems Inc., 123 Ehn Street, Suite 12, Old Saybrook, Connecticut 06475.
Adiacent Iilf7IIRlIOfiS shall be fastened with a minimum of three (3) 7+" self-tappins screws to prevent
movement and separation during backfilline.
Septic effluent will be transferred from the upper trench to each of the adjacent do*nhill trenches through
a serial distribution network as shown in the included graphics. The serial distribution connections between
adiacent trenches will facilitate the saturation of the uphill trench before septic effluent is allowed to flow
to each ofthe adjacent downhill frenches.
After the INFILTRATORS are installed, synthetic filter fabric (140-200 mesh) will be placed over the
INFILTRATORS and the system will be covered with a soil cap. The soil cap will consist of approximately
24" of sandy loam backfill. The soil cap will be mounded 5olo above the existing ground surface to promote
surface run off away from the soil treatment area.
The installer should confirm the feasibility of gravity discharge of sewage effluent from the foundation line
to the soil treatment areaby field verification of assumed design parameters. Assumed design parameters
with respect to gravity discharge include:
r If the distance from the sewage pipe at exit from the foundation line to the entry of the soil
treatment area is 50' or less,
. The elevation ofthe ground surface at the entry of the soil treatment area shall be no more than
15" above the invert elevation of the sewage pipe at exit from the foundation line.
If field measurements do not confirm these design assumptions, gravity discharge of septic effluent from
the proposed structure cannot be assured and a lift station may be required. Please contact the design
engineer and Mesa County to address any design modifications necessary if these design assumptions are
not upheld.
A 1,000 gallon, fwo compartment septic tank is required to provide a minimum of 48 hours retention time
for sewage generated &om the proposed project. A non-corrodible Orenco filter (model# FTW0436-28)
shall be iortun"a at the final outlet tee of the septic tank to limit the size of solids and sludge passing into
-2-
from the surface.
As shown in the included graphics, the trench soil ffeatment system will consist of trrro (2) trenches 3' wide
x 36" deep x 60' long with a total of thirty {30) INFILTRATOR (or equivalent) units. The soil treatment
area will encompass an effective atea of 514.29 sq. ft-
DESIGN CALCLILATIONS
DESIGNLOADiNG RATE OF 2 BEDROOMS @ 150 GAL./BEDROOM-DAY:300 gal.lday
DESIGN PERCOLATION RATE: 18 MIN./INCH
DESTGN LONG TERM ACCEPTANCE RATE (LTAR) :0.60 GAL./SQ.FT.IDAY
A: a . wHERE.LTAR'
A: SOIL TREATMENT AREA (SQ. FT.)
LTAR: LONG TERM ACCEPTANCE RATE (GAL./SQ. FT./DAY)
A: of, = 500 SQ'FT'
SOIL TREATMENT AREA ADruSTMENT FACTOR FOR GRAVITY TRENCH DESIGN : 1.0
SOIL TREATMENT AREA ADruSTMENT FACTOR FOR USE OF CHAMBERS :0.7
ADruSTED SOIL TREATMENT AREA: 500 X 1.0 X 0.7 : 350 SQ. FT.
LENGTH OF 3' WIDE TRENCH REQ',D : 350 SQ.FT. / 3 FT. : 116.67 FT-
USE 2 TRENCI{ES WITH 15 QI'ICK4 STANDARD INFILTRATORS (OT CqUiVAICNI) EACH,
CONFIGURED IN SERIAL DISTRIBUTION FOR A TOTAL OF 30 LINITS.
SOIL TREATMENT AREA SIZED AT 2 TRENCHES X 3FT WIDE X 60 FT LONG: 360 SQ. FT
-3-
Installation - Setbacks. Notifications. and Inspections
The owner and installer shall be aware of and comply with the following installation and system operation
requirements.
The installer must be approved and licensed by Mesa County for installation of onsite
rvastewater treatment systems.
All installation activities shall be conducted in accordance rvith current Mesa Countv OIZLS
Regzrlnlions. If at an:y time during construction. subsurface site conditions are encountered
which differ &om the design parameters oreviously described. construction activities will stop.
and the desisn eneineer and Mesa Counfv will be contacted to address anv necessarv desiqn
modifications.
The final cover shall not be placed on sewer lines, septic tank, or the soil treatment area until
the system has been inspected and approved by the design engineer and Mesa County. The
installer shall provide 48-hour notice for all required inspections.
Installationprocedures including grade, location, setbacks, septic tank size, and soil treatment
size shall conform with the attached graphic details. Construction activities and system
components will not encroach upon existing easements or utility corridors'
The installer must maintain all setbacks to utility lines, easements, property lines, or other
adverse conditions, whether they are known and shown on the attached graphics or have been
disclosed during construction. Vehicle traffic and parking is to be prevented over the soil
treatment and repair area. Minimum setbacks for system components are:
Septic Tank,
Dosine Tank
Building Server,
Effluent Lines
STA
spring/welVcistern 50 50 100
potable rvater supplv line l0 5 25
structure w/ crawlspace 5 0 20
stmcRrre r,r'/o crawlspace 5 0 10
property lines, piped or
lined irrigation
l0 l0 l0
subsurface drain,
intermittent irrisation
10 l0 25
lake, water course,
irrieation ditch, strearn
50 50 50
cut slope steeper than
3H:iV
l0 l0 25
septic tank 5
All gravity flow sewer lines and effluent distribution piping shall be 4 inches in diameter and
have glued joints. All lines discharging sewage from the residence to the septic tank shall
maintain a minimum fall of 118 in. per foot and shall employ sween 90's or 2-45's at all turas.
Sewer lines from the dwelling to the septic tank and at least 6 ft from the septic tank outlet
must meet minimum standard ASTM-3034. Lines discharging from the septic tank to the soil
treatment area shall maintain a minimum fall of i/8 in. per foot. Sewer lines under driveways
shall meet the minimum Schedule 40 PVC standards. Additionally, ef,fluent piping in traffic
areas with less than 24" of cover shall be encased in 6" CMP or flow fill and covered with
minimum 2" high density blue board insulation.
a
a
a
a
a
-4-
Sewer lines or domestic water lines shall be encased in minimum SCHD 40 with water-tight
end caps or aminimum of 6" of flow fill at all points with less than 5' separation between sewer
and domestic water lines.
Four-inch, two-way clean outs shall be installed at maximum 100'intervals in all gravity flow
effluent lines exceeding 100'in length.
A minirnum of 12" of soil cover (18" recommended) shall be maintained over all gravity
draining OWTS components to prevent freezing of septic effluent (excepting septic tank access
ports which must be extended to the ground surface).
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:
i. Excavation should proceed only when fhe moisfure content of the soil is below the
plastic limil. If a sample of soil fomrs 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 backfill equipment should work from the surface where at all
practical to avoid compaction of the soils at depth.
iii. 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 trorveled 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.
o
. The owner shall install a structural barrier if necessary and take precautions to prevent vehicular
traffrc, excessive surface watering, accidental flooding, or other activities in the vicinity of the
soil treatment area rvhich may corupact, satwate, or otherw'ise alter the subsurface soil
parameters used in designing the septic system.
r The owner will plant and maintain grass or other shallow rooted cover crop to prevent erosion
and promote evapotranspiration over the soil treatment arca.
r The owner will inspect and maintain the required mounding and drainage away from the soil
treafinent area to prevent safuration from precipitation and surface flows.
r To mitigate the generation of preferential flow channels which may compromise the operation
of the system, the owner will inspect and prevent intnrsion of burrowing animals and deep-
rooted plants into the soil treatment area.
o The septic effluent filter shall be inspected and cleaned as necessary every six (6) months.
r The owner will conduct periodic maintenance of the septic system by removing accumulated
sludge &om the septic tank every 3-4 years to preyent clogging of the soil treatment area.
a
a
a
a
-5-
Limitations
This report is a site-specifrc desiga for installation of an onsite wastervater treatment system and is
appticable only for the client for whom our work was performed. Use of this report under other
circumstances is not an appropriate application of this document. This report is a product of K-Cronk
Engineering, Inc. and is to be taken in its entirety. Excerpts from this report may be taken out of context
*J*oy not convey the true intent of the report. It is the owner's and owner's agent's responsibility to read
this report and become familiar with the recommendations and design guidelines contained herein.
The recommendations and design guidelines outlined in this report are based on: 1) the proposed site
development and plot plan as fumished to K-Cronk Engineering, Inc. by the client, and2) the site conditions
disclosed at the specific time of the site investigation of reference. K-Cronk Engineering, Inc. assumes no
liability for the accuracy or completeness of information furnished by the client. Site conditions are subject
to external environmental effects and may change over time. Use of this plan under different site conditions
is inappropriate. If it becomes apparent that current site conditions vary from those anticipated, the design
engineer and Mesa County should be contacted to develop any required design modifications. K-Crork
Engineering, Inc. is not responsible and accepts no liability for any variation in assumed design parameters.
K-Cronk Engineering, Inc. represents this report has been prepared within the limits prescribed by the
owner and in accordance with the current accepted practice of professional engineering in the area. No
warranty or representation, either expressed or implied, is included or intended in this report or in any of
our contracts.
SEAL
E &*,rA
Kachayla Cronk, P.E.
t)
Date
NOTE: This OWTS design is meant to include the following five pages:
1) plot plan
2) septic layout Plan
3) notes for your installer
4) soil treatment area Plan view
5) soil treatment area cross section.
The plan is not to be implemented in the absence of these sheets. In addition, results from the
a: 6n4o
U L!\$
o
,t
a il LA
soils evaluation are included for reference as
-6-
A.
I
15' utlllty &
drolnoge
easer4ent
/
6,agg dcre6
proposed
A,D,U,
slope
//
( \-
tr t)
roPProx, [ocation
,/ of exlstlng EVTSI-l
)
\
I
\
\
20' utltity &
drqlnqge
eoser'lent
(k3-\lr-
20' utltlty &
dnalhoge
eoseitent dr 15' utltlty &
drolnoge
easenent
\z --
exlstlng
resldence
-u$'"
:ELEMAN PRDJECT
LOl MONUMENT RIDGE REA!
2407-20e-26-0t0)LET PLAN
\4AY 7, a0a4
SCALET 1'=100'
I
il
N[RTH
NETE
GRAVITY I}ISCHARGE OF SEVAGE
EFFLUENT FREM THE RESIDENCE
TU THE DISPESAL SYSTEM IS
SASED NN THE FILLEWING NES]6N
ASSUMPTIENSI
LENGTH !F SEVA6E PIPING
FREM EXIT AT FEUNDATIT]N
LINE T[ ENTRY TE SDiL TREATMENT
AREA - 50' ER LESS
ELEVATIDN EF GRDUND SURFACE
AT ENTRY TE SIIL TREATMENT AREA
= Nn MDRE THAN 15' ABIVE THE
INVERT ELEV, [F SEVAGE PiPE
AT EXIT FREM FIUNDATION LINE
D]SCLAIMER
IF THESE IESIGN ASSUMPT]INS ARE
NET UPHELD DURING CENSTRUCTION,
GRAVITY NTSCHARGE CAN NOT BE
ASSURED AND A L]FT STATION MAY
5,288 qcres
drlve
I 6', -l- 10'JI mln, ' nln, '
-t--l
olul '
i9'
oQ
sj
![D,is ,''
+i<;oY'il
ilI *.
n
0,L
d
-!
o-
0,I
fltter ([SI Modet
FTW0436-e8)
tneotnent oneo (STA)
conslstlng of 2 rows of 15
Qulck4 Stondord Inflttnotors(or equlvotent) for a totolthlrty unlts conflguned ln
serlal distrlbutlon os sholn
cleon
out
stope
tit:l_-i
I
I
+rc0
E
0ru
d
0,
0,
o)d
.g
l.?
&
g
+5
btu
-{t
.-{t'
z*
.-n-'
..4-"
oost'
NDTE
CENTRACTER TE VERIFY
SLIPEI SOIL TREATMENT
AREA BRIENTATIEN TO 3E
ADJUSTED PER SITE
VARIATIENS TtT FACILITATE
CENSISTENT TRENCH I}EPTH,
RUNNING PARALLEL TO
CNNTOURS,
I
NETE
THE FILLEVING SETSACKS MUST BE MAINTAINEDI
SEPIICTANK STA
LAKE/STREAM/IRRIG. DITCH-50'
INTERMITTENT IRRIG, DITCH-10/
100'
50'
c3
10'
100'
a5'
e0'
t0'
10'
SELID PIPE/LINED DITCH
DD|,IESTIC VATER CISTERN
-
s0/
DEI"IESTIC VATER LINE
STRUCTURE V,/CRAVLSPACE
-
5'
STRUCTURE V/ECRAVLSPACE-5'
10'
10'
CATED PIPE
SPRINGS/VELLS
PRIPERTY LINE
NETE
NETE
IF SITE CENDITIENS LIMIT
PRACTICAL INSTALLATIEN EF
STA AS SHEVN, INSTALLER
MAY CENTACT ENGINEER TE
MEI'IFY TRENCH LAYOUT
PRIER TE INSTALLATIEN,
NETE
AN I]ESERVATIEN HELE VITHIN 50' IIF THE
PREPESED STA MUST BE PREVIDEI} BY THE
CLIENT TE THE DESIGN ENGINEER FER
INSPECTTEN PRIER TE INSTALLATIEN.
SHEULI} SEILS DIFFER SIGNIFICANTLY FREM
DESIGN ASSUMPTIENS, A REVISED DESIGN
MAY 8E REOUIRED.
i!LEMAN PRDJECT
IO1 MENUMENT RIDGE ROAD
?407-?0?-?6-010
SEPTIC LAYIUT PLAN
vtA\ 7, ?0?4
SCALET 1'=30'NORTH
T(-CROAIT(P.0. .Box 4o
,14ac/r. C0 Sr
t)
Z CI. p i CI. o i 7 2 f ktr chay I a. n' an Ie O,t o rr tlont..ot n
NOTES FOR YOUR INSTALLER
o Please veriti slope at the time of system installation - the orientation of the
STA shown in this design has been determined based on existing site
conditions at the time of the original site investigation, but that may have
changed during construction and pre-construction gfading of the site.
o The depth of the ffenches is determined by percolation rates and soil
conditions relative to the existing ground surface at the time of the soils
investigation. If the site slope or grading of the ground surface at the time of
installation differs significantly from what was initially observed, the trench
depths may have to be adjusted to make sure the infiltrative surface remains
in the desired soil layer, and portions of the trenches don't end up too deep or
too shallo'67. The depth of the soil cap relative to finished grading is not part
of the OWTS cr{teria.
r Please provide K-Cronk Engineering with a copy of the septic tank
manufacfurer's specification sheet verifying maximum backfill depth. Tanks
must be backfilled according to manufacturer's specification.
Pressurized Systern Notes
o Please provide K-C.ronk Engineeri.ng a copy of the sand sieve analysis, if
relevant,dated within 30 DAYS of installation before purchasinglinstalling
the sand so we can check that it meets Mesa County OWTS standards.
r Pump floats do not come pre-set from the factory. Please refer to the Pump
Vault Detail for the distance needed between the on/off floats.
Please reach out at any time during the installation process if you have any questions!
Kachayla Cronk - (970) 250-0572
trvo (?) rows of flfteen (15) OUICK4
STANDARD INFILTRATIRS (or equlvotent) For o
totot of thlrty (30) unlts conflgured ln
serlot dlstrlbutlon os shown, typ,
65' w/ endcops,
o€ chonbers, typ
'tYP'
lc lnftuent
aooc
0,
Eeo
U
0,!
;r
provlde lnspectlon,/vent
ponts ot eoch end cap,
fosten odjacent Inflttrators
w/ <3) 3/4' scnews ot
approxlnatety 10 o'clock, 12
o'ctock, ond 2 o'ctock posltlon,
tvp,
SI]IL TREATMENT AREA - PLAN VIEV
SCALET 1'=20'
SCREV DETAIL
NTS 4' SCHD 40 PVC
VENT/INSPECTIEN
PERT AT EACH ENI)
CAP, TYP.SIIL CAP
SERIAL DISTR]BUTIEN
EUTLET - USE HIGH
KNICK EUT, TYP, (END
[R SIDE)
SERIAL DISTRIBUTION CONNECTION DETAIL
SCALE: 1/2"--1'
SERIAL }ISTRISUTIDN
EUTLET - USE HIGH
KNOCK EUT, TYP, (END
IlR SIDE)
(10' r
conf lgunotlon, cttenno
serlat dlstributlon
end-to-end, typ,
SCREVS, TYP
(SEE DETAIL)
:ELEMAN PRIJECT
IOl MDNUMENT RIDGE ROAI)
a407-e0a-e6-010
SDIL TREATMENT AREA - PLAN VIEV
vAY 7, e0e4
SCALET 1'=?0'
serlat dlstnibutlon connectlon
designed to assune saturotlonof upgradlent tnench before
efftuent ls ottowed to overflowto odjacent downgrodlent trench
CINNECTIENS MUST 3E I'IANE FRDMexlstlng gnound THE HI6H KNECK-DUTS BF EACHsurfoce wlth stope END CApS
synthetlc fltter
fabrlc, typ,
lnspectlon./v"ntlng port
ot eqch end cop
soit cop, provlde
r,rln, 52 drolncge
nqx, 3Hr1V(332 stope)
\o ru
o+oc
0,0nNtlTEl
IF CINSISTENT TRENCH NEPTH
CANNIT BE MAINTA]NEN,
INFILTRATIR CHAMBERS MAY 3E
INSTALLED LEVEL AT A4' MIN.
AND 48' MAX BGS
4' nln,
(10' neconnended)
typicot Infittrotor trench
cnoEs sPctlon (one of tuo)
dlsk or scot'lfy unden
eqch Inflttroton trench
QUICK4 STANDARn INFILTRATIR (or
equlvqlent) Insto[ In occordonca wlth
'INFILIRATBR TECHNICAL HANUAL', ovdltalolefron Inflltrotor Systens Inc,, 1e3 Eth
Street, Sulte 12, Etd Soybrook, Cannectlcut
06475
SEIL TREATMENT AREA (STA) - CRI]SS SECTiEN (TYP. TVE T]F TVt])
SCALET 1'=5'
SIILS LIG BY ETHERS - SEE APPENDIX A
CILEMAN PROJECT
IOI MDNUMENT RiN6E READ
a407-a02-e6-010
SEIL TREATMENT AREA - CRDSS SECTIEN
MAY 7, 2824
SCALET 1'=5'
ELEVATIDN I}ESIGN SPECIFICATIENS
FRIM FIUNDATIIN LINE TE INLET !F SEPTIC TANK = 10,
FREM EUTLET EF SEPTIC TANK T! STA = 10'
ATIIN [F GRIUND SURFACE AT ENTRY T[ STA = 100,00'
B0TTOM 0F INFILTRATIR AT ENTRY TE STA = 97,00'
TIEN trF SEVAGE LINE AT ENTRY TE STA = 97,50,
ATI0N UF SEVAGE LINE AT DUTLET [F SEPTIC TANK = 97,70'[F SEVAGE L]NE AT INLET EF SEPTIC TANK = 97,95'
ATInN UF SEVAGE LINE AT F0UNDATIEN LINE = 98,15'
ASSUMEI)
DESIGN
DESI6N
ELEVATIIN
INVERT ELE
INVERT ELE
INVERT
INVERT
Appendix A
Soils and Percolation Report
&u,* flolu***
.j ., ti:.i-j
..:,:i':i,'. ':t..\
November tr3,
Tapestry
Attn: Jerre
P. O. Box
Parachutq
Subject:
Sear Jerre:
As requested"
perc,olation;test
was condu$ed in
Tapestry
based on the
in this report.
Fropesed
looated snthe
over crawlspace.
loadi'S fsl,tbis
prsposed type
narfbwest ofthe
lfbuilding
described abovg
this report. :
Sit* Caladi€i*ns
terrain "li the
Fia'. 'ri ir,e
.t !r;\\'-t.?;r '_l
*:--:--.,:--.--.--
81635
Job No. 109 3Bl
Design and Percslation Tesl ?mposed
10, Monume,nt Ridge, Monument Ridge Road,
Inc. performed a sirbsoil study and
disposal designs at the subject site. ?he studyi
wiil be a singie story wood frame structure
Smund flsors will b€ sfnrciurally
t<r rang€ betu/een about I to 5 &et.
aszurned to be relatively light and qypical
dispcsal system is proposed tc be located
slightly furtlrer west than that ehown on
are significantiy different fiam those
re-evatuate the reeastrmendations presented i4
'1
i
1
.:1
ground $rrface aFpears $iostiy natural- The
lr.,itl'l a strcng slope dor,r'n to the rvest.
buiiding is abaui 4 ic 5 feei. trrogetation
Tin'e ls a s":.:lic-",' :i::h aiong tire sauti: s!i.'
lA
S*rdy
Cc
oEf
?'7
accordance
as shown
Cut de,pths
dated
sf
Figure
The
shot]ld
The lat is
e gcr*ss
;.f---"i-.* --'
01'
&TCA ls
;'iL:
{
in
-2-
conditions at t}e site were evaluated by
araa and one profile pit in tha septio
shown cn Figure l- The logs ofthe pits are
/r foot oftopsoil, consisted ofmdiumdensq
clayey to silty gravel aud eobbles underlain at deptltswith
from 5 feet by ta derrsq clayey sandy gavel and cobbles
small maximunr depth explcred af 9r/t feet'
testmg relaitively usdisfu*ed samples oftbe sand
presented'on 3,ulrder exist*rg moistse
disposal
presentedlcn
I
:
The subsoils
sarnpies
coiiapse
2.
amlnor
rn'hen
of
and liglit anil when loaded after wetifurg.
and the othc sarxPle showed
One oftle:
arrunof
gradation and
sa:rd soiis
the pits at,the
test
of
4. The
E"oundatign
clayey soils will
these be
rlsk of
be taken
poteatial rn one
neglected &rsrdation
sonditione inthe
constructi6n.iower risk
bear the er*irelY on
F'ound*tloP
soiis designed
the propesed
there could be
expected ts be
settlemant
I
Footings
in Table I. No &ee water was obsprved ia
ssils were slightlY moist-
assumed excavation grades, the clayey to very
exposed at subgrade- $pread footings bearing
srlFport of the building with some risk
ifthe bearing soils become wetted
wetting ofthe bearing soits. The low
1% inch
18 inches fcr continirous
soils encauntered at the
j
:
walls and 2 fect fori
foundation bearing,level
low
8re
and
fer
15
the
ta 1 inch
bea
all
The
aad
soils.
Gee
calurnns. All
within
The
for
grade is used il3 atea.
reinforced tap bottorn
some
lateral
site soil topsoii
anom*iies and be*ter withstand the affect* af
assuming ac msupported lengtk of at least 12
-J-
fouadation wa1!s shotld be weil
strucftIres shouid also bc designed to resist
'l
of at least 50 Pcf for the
to
the nng
rior
as
rrails as
based a$fluid unit weight
racks" as beckfiiL
o&-
it
develop
grormd dwing
grade such as
protected and
The con$ist
the invert
be placed level of
grade ata
material used the
sieve, less
drain gravel should
of hezuy prrecipitation or seasonal ru$off
also a perched condition. We recoslrrrend
a:rd relarively deep atewlspace areas, be
pressure buildup by an underdrain systetn
placed in the battcmof the wall backfitrl
fre+drsixling granular material' The drain
at least I footbelow lowest adjacant finish
a suitable granity oatlet' Fre+draining
sirould contain less than2%passiag theNo'
sier.e andhave a maxintum size of 2 inches'
lt4&et deep.
the foundation iri atl directiciis' We
€Jnderdraisr
bas been our
grormdwatcr
Sarfaee
preverit
sbserved
cornpleted:
rl1 area
r)
2\
5)
of the
ided
ground
to
soile.
nway
r%
atd
tn
Na.
at
illlltllr!l
utnail.IJob No. 1
slope of 12 inches in the first l0 feet in
bees
and e
5 feet
the feasibitity an
rrere dug
12 inch by tZ
and were
holes are
clayey to
study
0n
do
The
abautTtA I
USDA ssll
{LTAR} df
based cn Sate
.:
Colorado
!.,i*ritatigPs:
- l: tgeotecnnrcar
warrat*y
inthis based
locatiots
the atea. ,
ofmold biolcgical
ts
findines
may net evident
once so
-4-
of 3 isches in the first 10 feet in pavement
inay be neded uphill to dir€ct surfrce nuro tr
slrauld discharge well beyond the limits o
4
regultr heavy inigation shouldbe located at
w€f,e condtrcted oa November 3, 2009 to
system at the site. One profile pit and three
shovm on Figure 1- The te$ boles
trand dug at the batiom of shallcw backhoe
and the percolation test results, the *sted
ut acccrdance with generally accepted
practices 1n this &ea at this tima w makee
The cooclusions and recommendations
*omthe exploratory pits excavated
type of construction and our 1n
the presence, Prevention or
{MOEC} developing inthe futura lfthe
inthis special field ofPractice ba
and extrapolation of the subsurface
described in this report' we should be at
the
rnd
lall
5).
i
:
l
FeraoEafion
withwatsr to testing. The soils exposed in the
to thasp Frofile Pit shorun on Figure 2 and consist of
silty gravel and cobbles"
test rEsults in Table 2 and indicate percolation rates
p€r an av€rags of 11 minutes per inch' According
is Sandy Lsarn The long tern acceptaace
Loam is to be about 0.72 gailons per squale fcot per
Sased on'ths
area shoeld be for infiltraiion septic disposal systert A
professional destgn systern
at the pib and variations m the subsur&ce
15 performed.If canditions encorrntered
JobNo. 109
af may bemade.
I
u.g.
.150 .3
dFTEft OF
st
9L
100
s0
80
m
6096(Adq-
50F 2
KJ{,,g.
Ll
48&
g0
20
l$
0
FROhd: Profile Pii from 3 Feet tc 4 Feet
75.2 152ln
co€a.B
s.s 19.0 s7.5
1A.S
CLAY 7 7o
PLAS?ICITY INDEX %
4"?5
AHTiCi.ES IN }.}ILUMEIEFS
i ^SS$ 1-18
srlt 17 %GHAVEL 2a, % ii
:i!l
::
UGUID UMf
USDASOILTYP€: Sandy
7HRl5Mtlt
.037 .074.0s1 .00s .006
cnY
SAND
V"
Loam
24
o.45
10
4V
30
7A
80
g0
t3tuJ 40A
F
!J
Fs0
Zt$()
0:td0- 60
rbcft A?FigureUSDA GRADATION TFST RE$ULTS1CIg 3814 --cs
HEFLniAFIi-t'ItAlgl
I
'l
F{$prry0RYH*pA$rrAK SsST€eHNtffi6 3gg.
TAR!"[ I
$IJffifrfrANY SF TABONATORY Tg$T RHSUTT$
Job l{cu IOP SqA
Vsry 9laysy silty saud with
rvrnqrral
Clnyey sihy sard
Very claycy silty $ancl
Sandy L,oam
s0ltsn
BEOftOCKTYPE
lps,Fl
uileoilflNrD
coffipn$gnr6
SIBENgnr
pm$K
tilDex
fid
ATTEABERGU'{Iffs
uoulbiliilr
tv,l
24
pEncElff
pt$stN0
ilato0 /
grEffi
52
g/d
$ANS
M
06t
GftAVFt
10s
85
$2
(edl
lgjqt tJtU'&L
T}RY
brN5fff
5.8
7.2
71
t%t
tltl|ttvfi'4L
MSt$[t FE
CONIENT
4
34
nspth
{frl
4
112
A
I
2
Prctil
SAIJI
plf
SARN
LOT 1CI
2
PIT T
PROPSSES
RSSIDENCE
I
I
;
CH b.{ARK: GROU}IS AT
CORNER;ELFd. : -l0o.o', AsgliM
LfGfND:
x pRoFlLE FIT
A Pgncor-arsru HOLE
?t
11
APPROXIMATE
PENCOLATION TEST HOLES109 3B1A
GE#TECHI*ICAI., iNfr"
TAB&-E 2
TEST RE$ULTS
.tsB ,tsg 38tA
20s9.
{ss9,
Note:
GN
tne
AVERAGE
pERC6LA?loht
.; RATE
tnf$dJ!!sGll,
sRoP ll*
WATER
LffiEL
{r}rsHEs}
WATER
DEPYH&T
$?ARTOF
lgdTERltAr-
{rNGFfss}
UTTA;rER
DEPTfi AT
HFiIg OF
i$TERVAL
{8NC}rEs}
E,,H
:alt
E E${
II{TE
{R
i$t oF
IVAI-
N9
F{OLE ffiS.i !{Sl
: DEF
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I
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i
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'1.123Y"
x
ref
t
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2r/*\tr/a ts
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Vlz,3
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refi
t
led
i
ce
i
.
p-2
2T*'!3Fle 71'12
l?a96/oj'tYz.
'!:&&Ye*/a
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tl4&e/"#/e
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1
I
.!
n
€7A3%8/a
P-3 48
6nt
nber
nge
hoies
2,380S.
316 hAr
'rsslatra&s 1
da*g in Sre hotforvr of backfuoe pi€a and
tes* weile ssnducted sct F{ovEnnber
based en t&e €asttryo readE$gs oF