Prelim Storm Drain Report 001February 9, 2007
Proponent: Judd and Sarah Sherman
(360) 458-1976
Prepared by: Justin Goroch
Reviewed by: Don Mellott, P.E.
BCRA
2106 Pacific Avenue, Suite 300
Tacoma, WA 98402
(253) 627-4367
BCRA~
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I hereby state [hat this Storm Report for the Today's Dental has been prepazed by me or under
my supervision and meets the standard of care and expertise which is usual and customazy in this
community for professional engineers. I understand that the City of Yelm does no[ and will not
assume liability for the sufficiency, suitability, or performance of drainage facilities prepared by
me.
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TABLE OF CONTENTS
CHAPTER 1 - PROJECT OVERVIEW 3
CHAPTER 2 - EXISTING CONDITIONS SUMMARY 3
CHAPTER 3 - OFF-SITE ANALYSIS 3
CHAPTER4- PERMANENTSTORMWATERCONTROLPLAN 4
CHAPTER 5 - DISCUSSION OF MINIMUM REQUIREMENTS 4
CHAPTER 6 - OPERATION AND MAINTENANCE MANUAL 5
APPENDICES
APPENDLX A -VICINITY MAP
APPENDIX B -MANUAL REQUIl2EMENTS
APPENDIX C - GEOTECHNICAL REPORT
APPENDLY D -PRELIMINARY STORM DRAINAGE CALCULATIONS
APPENDLX E -PRELIMINARY WATER QUALTTY CALCULATIONS
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The Today's Dental project is located at the north comer of the intersection of Solberg Street and
the west comer of the intersection of Solberg Street and Jefferson Avenue. The site consists
parcel numbers 21724142300, and 217241452200. The pazcels aze zoned C-1 Commercial. The
site lies in Section 24, Township 17N, Range lE. See Appendix A for a vicinity map.
The project is comprised of a 0.60-acre site which will contain a dental office building and a
pazking lot. The site will have ingress/egress points from Solberg Street. Runoff from the
pazking lot is captured and treated for water quality using StormFilter cartridges. Runoff from
the roofs is captured and conveyed to a StomrTech chamber infiltration system [o be infiltrated
along with the treated water.
The project will also require frontage improvements on Yelm Ave., Solberg St, and Jefferson St.
Runoff from [he improved half streets will be captured and treated by two separate water quality
facilities utilizing StomrFilter cartridges. After treatment the runoff is conveyed to two separate
StormTech chamber infiltration systems to be infiltrated.
All Minimum Requirements aze applicable to this project. See Chapter 5 for a more detailed
explanation.
The site currently has a dental office building on one pazcel and a single family residence on [he
other pazcel. The existing ground cover is a combination of lawn, landscaping, and gravel. In
general, the site slopes from west to east with slopes ranging from relatively flat to 4%. The
natural drainage path for the site is sheet flow from north to south with the existing stmctures
being local high points. Based on the soils information, we believe that the site has the ability to
infiltrate most if not all onsite stormwater.
To our knowledge, there have been no erosion problems pertaining to the site, [here aze no
critical or sensitive azeas, the project does not contain any difficult site conditions, and there aze
no specific requirements included in the basin plan. Also to our knowledge, there aze no fuel
tanks, wells, or septic drain fields located on site.
The site is bordered to the west bymulti-family residences and a commercial building. Jefferson
Avenue borders site to the north. Yelm Avenue (SR 510) borders the site to the south. The site
is bordered by Grave Road to the west.
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Based on soils information from the site we believe that most if no[ all runoff infiltrates. The
developed site will use an underground infiltration facility to best mimic existing conditions.
Since infiltration is utilized a downstream analysis is not provided.
Flow Control System
The site will utilize a StormTech chamber system to infiltrate onsite runoff The system consists
of plastic dome shaped bottomless chambers backfilled with porous drain rock. Based on the
geo[echnical report by E3RA dated 1/5/07, an infiltration rate of 10 in/hr is used for the design.
The footprint of the system is approximately 11 fee[ wide by 54 feet long with approximately 14
chambers. See Appendix D for calculations and typical details for the system. See Appendix C
for [he geotechnical report.
The frontage improvements will also utilize StomrTech chamber systems [o infiltrate runoff As
with the onsite system 10 in/lu is used for the design. The foo[ptin[ of [he system in Jefferson St.
is approximately 6.25 feet wide by 32 feet long with approximately 4 chambers. The footprint of
the system in Yelm Ave. is approximately 6.25 feet wide by 39 feet long with approximately 5
chambers. See Appendix D for calculations and typical details for the system. See Appendix C
for the geotechnical report.
Water Quality System
Runoff from the parking lot will be treated using S[ormF'ilter cartidges manufactured by
Contech Stonnwater Solutions prior to entering the StoanTech chamber system. Runoff from
the frontage improvements will also be treated using S[ormFilter cartridges prior to entering the
StoanTech chamber system. See Appendix E for the water quality calculations.
Conveyance System Analysis and Design
Runoff from the pazking lot is captured by a series of catch basins and conveyed [o the
StormFilter system for water quality treatment. The runoff is then conveyed to the S[ormTech
chamber system where it is infiltrated. Since roof runoff does not have to be treated for water
quality, i[ is captured and conveyed separately from the runoff from the pazking lot. It is also
conveyed directly to the StormTech chamber system. Runoff from the frontage improvements is
captured and conveyed to the StonnFil[er system for treatment and then conveyed to the
StormTech chamber system to be infiltrated. All conveyance systems will be sized far the 25-
yeaz storm event.
Minimum Requirement #1: Preparation of Stormwater Site Plans
Final plans and a report will be submitted with the final design.
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Minimum Requirement #2: Construction Stormwater Pollution Prevention Plan (SWPPP)
A SWPPP will be provided sepazately along with the final report.
Minimum Requirement #3: Source Control Pollution
Pollution will occur primarily via passenger vehicles driving and parking on-site. There
are no applicable source control pollution prevention options relevant for such modes of
pollution. Polluted Stormwater will be treated by a SlormFilter system.
Minimum Requirement #4: Preservation of Natural Drainage Systems and Outfalls
This proposal utilizes onsite infiltration.
Minimum Requirement #5: On-Site Stormwater Management
On-site stomtwa[er management is accomplished with the use of planned site grading,
catch basins, water quality treatment systems, and an infiltration system.
Minimum Requirement #6: Runoff Treatment
The proposal utilizes StormFilter systems for treatment of runoff from the parking lot.
Minimum Requirement #7: Flow Control
Flow control is not applicable since infiltration is utilized.
Minimum Requirement #B: Wetlands Protection
No jurisdictional wetlands exist on the site.
Minimum Requirement #9: Basin/Watershed Planning
This is not applicable since infiltration is utilized.
Minimum Requirement #10: Operation and Maintenance
An Operation and Maintenance Manual will be provided with the final report.
An Operation and Maintenance Manual will be provided with the final report.
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APPENDIX A
VICINITY MAP
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APPENDIX B
MANUAL REQUIREMENTS
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STORlIWATER NANAGENENT NANUAL FOR TEIE PUGET SOUND BASIN
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STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUNU BASIN
Figure I-3.7 Flowchart Showing Steps for "Hybrid" Projects
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APPENDIX C
GEOTECHINCAL RF,PORT
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PO Box 44890
Tacoma WA 98444
253-537-9400
253-537-9401 faz
E3RA
January 4, 2006
T06397
Yelm Dental Center, LLC
502 Yelm Avenue West
Yelm, WA 98579
Attention: Dr. Sarah Sherman
Subject: Geotechnical Engineering Report
Planned Commercial Development
502 Yehn Avenue West, P/N 21724142300
107 Solberg Street, P/N 21724142200
Yelm, Washington
Dear Sarah:
E3RA is pleased to submit this report describing the results of our geotechnical engineering evaluation forthe
residentral development planned at 502 Yelm Ave West and 107 Solberg Street in Yehn, Washington.
This report has been prepared for the exclusive use of Yehn Dental Center, LLC and their consultants, for
specific application to this project, in accordance with generally accepted geotechnical engineering pmc[ice.
1.0 SITE AND PROJECT DESCRIPTION
The planned commercial development is located on the comer of SR 510 and SW Solberg St. in Yelm,
Washington, as shown on the enclosed Location Map (Figure 1). It consists of two rectangular parcels that
measure about 80 feet fronting SR 510 and 300 feet fronting Solberg Street. The project site is currently
bordered by SR 510 to the southwest, Jefferson Ave to the northeast; and Solber St to the e95L Surface
topography is relatively level.
Plans call for the removal of the existing home and dental office and wnstrucfion of a new dental office,
associated parking, and a storm water infiltrafion facility. The properties will have access from Solberg St.
2.0 EXPLORATORY METHODS
We explored surface and subsurface conditions at the project site on November 18, 2006. Out exploration
program comprised the following elements:
A surface reconnaissance of the two parcels;
Ten test pits (designated TP-1 through TP-3), advanced across the site;
One Grain Size analyses of on-site soils;
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Three Infiltration Tests; and
January 5, 2007
T06397 ! Yelm Dental
E3RA, Inc.
A review ofpublished geologic and seismologic maps and literature.
Table I summarizes the approximate functional locations and termination depths of our subsurface
explorations, and Figure 2 depicts Shea approximate relative locations. The following text sections describe
[he procedures used for excavation of test pits.
TABLE 1
APPROXIMATE LOCATIONS AND DEPTHS OF EXPLORATIONS
Termiuafion
Depth
Exploration Fmcfional Locafion (feet)
*TP-1 Southwest site 8
*TP-2 Central part east site 10
*TP-3 Central site 10
* Includes infiltration test
The specific number and locations of our explorations were selected m relation to the existing site features,
under the constraintsof surface access, and underground utility conflick.
It should be realized that the explorations performed and utilized for this evalua5on reveal subsurface
conditions only at discrete locations across the project site and that acmal conditions in other areas could vary.
Furthermore, the nature and extent of any such variations would not become evident until additional
explorations are performed or until construction activities have begun. Ifsignifican[ variations are observed az
thattime, we may needto modify om conclusions and recommendations contained in this report to reflect [he
actual site conditions.
2.1 Test PitProcedures
Our exploratory test pits were excavated with a steel-tracked excavator operated by an independent fmn
working under subcontract [o E3RA. An engineer from our firm continuously observed the test pit
excavations, logged the subsurface conditions, and collected samples. After we logged each test pit, the
excavator operator backfilled it with excavated soils and tamped the surface.
The enclosed Test Pit Logs indicate the vertical sequence of soils and materials encountered in each test pit,
based on our field classifications. Where a soil contact was observed to be gradational or undulating, our logs
indicate the average concoct depth. We estimated [he relative density and consistency of the in-sim soils by
means of the excavation characteristics and the s[abiliTy of the test pit sidewalk. Our Togs also indicate [he
approximate depths of any sidewall caving or groundwater seepage observed in the test pik, as well as alt
sample numbers and sampling locations.
2.2 Infiltration Test Procedures
We performed fallinghead infiltration tests at a depth of about 7 fee[ within test pits TP-1, 2, and 3. All falling
head tests were performed in general accordance with the falling head type infiltration testing procedure
described in the EPA publication On-site Wastewater Treatment andDisposol8ystem 1980, described below.
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January 5, 2007 E3R4, Inc.
T06397 / Yelm Dental
A 6-inch-diameter P VC pipe was tamped 3 to 5 inches into the soil of the upper part of the infiltration layer,
then 2 inches of coarse, clean drain rock was placed at the bottom of the pipe to prevent scouring. Soil waz
placed and tamped outside the pipe far stabilisation and to prevent upwelling oftest water around the pipe. The
pipe was then filled twice with 1 foot of water to pre-saturate the test soils. Because, th all Gazes, 1 foot of
water infiltrated the test soils m less than ]0 minutes, further saturation was deemed unnecessary and the
infiltration test proceeded.
The pipe was then filled with 6 inches of water, and, because site soils were found to be rapidly permeable,
the time requhed for infiltration of the entire fi inch column of water was recorded. We repeated this
procedure three times at each test location and used only the slowest of the 3 recorded infltration rafes m
our analysis.
3.0 STTE CONDITIONS
The following sections of text present our observations, measurements, fmdings, and interpretations regarding,
surface, soil, groundwater, seismic, liquefactioq and infiltration conditions.
3.1 Surface Conditons
The project site is relafively level with no noticeable change in elevation.
The 502 Yehn Ave West pazcel currently has an existing Yehn Dental Office and 107 Solberg Street currently
has a home on the lot. The remainder of the sites are yard or parking.
Vegetation onsite consists of grass and some small yard trees.
No signs of surface flow, such as stream charnels or erosional scars, were noted during our reconnaissance.
No ponds are onsite. No seeps or springs were observed.
3.2 Soil Conditions
Om on-site explorations revealed fairly nearly uniform neaz-surface soil conditons.Generally, we observed
an upper sod and topsoil layer that ranged th thickness from %z [o abit less than I foot in thickness overlaying a
black ash layer with gavel ranging to a depth of about 2 1/2 to 3.0 feet Underlying the ash layer, we
observed, to Ore temrina5on of our explorations, which reached a maximum of about ] 0 feet, gravely glacial
oulwash with cobbles and boulders. The soils appeared to become somewhat sandier and slightly less to the
north and west. Caving was noted ar depths of about 4 1/2 to 5 feet in the test pits, suggesting that water will
readily infiltrate at these depths due to the nature of the soils and lack of silts.
The enclosed exploration logs provide a detailed description of the soil strata encountered in our subsurface
explorations.
3.2.1 Laboratory Testine
Om Gram Size Analyses of the sandy gravel in test pits TP-1, found within the zone where infiltration will
likely occur (7 feet below current grades) indicate that the silt content is ht the range of 5 percent.
The moisture content ofsoils within the zone of infiltration is about5 percent as well Weinterpret mostofthe
upper soils as being close to optimum moisture.
The enclosed laboratory testing sheets graphically present curtest results, and Table 2 summarizes these
results.
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January 5, 2007 E3RA, Inc.
T06397 / Yelm Dental
TABLE2
LABORATORY TEST RESULTS FOR NON-ORGANIC ON-SITE SOILS
Soil Sample and Moisture Gravel Content Sand Content Silt/Clay
Depth Content (percent) (percent) Content
ercent) (ercent
TP-1, S-1, 7 feet 5.1 70 24.8 5.2
3.3 Groundwater Conditions
At the time of our reconnaissance (November 18, 2006), we did not observe goundwater m any of our
explorations, which extended to depths of up to 10 feet. No significant mottling was observed.
It is not anticipated that ground water will be encountered during typical onsite consimction activities.
3.5 Seismic Conditions
Based o¢ our analysis ofsubsurface exploration logs and our review ofpublished geologic maps, we interpret
soil wnditions on the site to correspond with a seismic site class Sc, as defined by Table 16] 5.1.5 ofdre 2003
Internafional Building Code (IBCJ. According to the IBC, the site is Seismic Region 3.
3.6 Liquefaction Potential
Liquefaction is a sudden increase th pore water pressure and a sudden loss of soil shear strength caused by
shear strains, as could result from an earthquake. Research has shown that satummd, loose, fine to medium
sands with a fines (silt and clay) content less than about 20 percent are most susceptible to liquefaction. We
did not observe easily liquefiable soils onsite.
3.7 Infiltration Conditions
A storm water infiltration faciliTy is planned for the site. In our three test pits located in the vicinity of this
faciliTy, test pits TP-1, 2, and 3, we observed loose silty sandy gravel with afines content that averaged aboutS
percent. According to the U.S.D.A. Textural Triangle, om laborazory analyses of this soil indicate that it E a
gravel, course sand type A with an intilnadon rate of 1 minute/inch.
The results of om infdtrazion tests are presented rtr Table 3. Because infiltmtron was moderately rapid, we
recorded the time necessary fora 6 inch high column of water to infiltrate completely as discussed in section
2.2 above. Based on our field testing, the Average Infdtation Rate for soils at a depth of 7 feet is 3.0 minutes
per inch. After incorporating a Factor of Safety of 2, we recommend aDesign hrfiltratron Rate of 6 minutes per
inch (I O inches per how).
TADLE 3
FIELD INFILTATION TEST RESULTS
Test Depth below
Field Infdtration Rate for 6
Number Location esisti fg
grades inch Column
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T-1 TP-1, parking azea 7 20 miN6 inches
T-2 TP-2, front yard of home 7 20 min/6 inches
T-3 TP-3, back yard of home 7 8 min/6 inches
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T06397 / Yelm Dental
E3RA, Inc.
4.0 CONCLUSIONS AND RECOMMENDATIONS
' Plans califor the prepaza[ion ofanew deutaloffice, paved pmking and infiltration of storm water on site. We
offer the following conclusions and recommendations:
' Feasibili Based on our field explorations, research, and analyses, the proposed
development appears feasible fiom a geotechnical standpoint, provided that the
' recommendations in Section 4 and in [his report are followed.
~i' Foundation Options: We recommend conventional spread footings supported on fumly
compacted native soils. Recommendations for spread footings are provided in Section 4.
' Floor Options: We recommend either a concrete slab-on-grade orjoist-supported floors for
the proposed commercial structure. Some over-excavation will be necessary for slab-on-grade
floors. Recommendations for slab-on-grade floors are included m Section 4.
• Onsite Infiltration: Based on our onsite infiltration tests and soils analyses, we recommend a[
' Design Infiltration Rate of 6 minutes per inch for soils m the vicinity of the planned
infiltration facility.
• Asphalt Pavement. Stmcmral fill subbases appear do not appearto be necessary provided that
sub-grades are compacted to 95 percent maximum dry density. A pavement secfion,
consisting of 2 inches of asphalt pavement over a 4 inch crushed rock base, is recommended
' for the planned parking area.
The Following text sections of this report present our specific geotechnical conclusions and recommendations
' concerning site preparation, spread footings, slab-on-grade floors, drainage, subgrade walls, and sWCtural fill.
The WSDOT Smndard Specificafions and Standard Plans cited herein referto WSDOT publications M41-10,
Standard Spec~catfons for Road, Bridge, and Municipal Consrrucfion, and M2]-Ol, Stardard Plans for
' Road, Bridge, and Municipal Courructian, respectively.
4.1 Site Preparation
' Preparation ofthe project site should involve erosion control, temporary drainage, clearing stripping, cutting
filling excavations, and subgrade compaction.
1 Erosion Control' Before new consWction begins, an appropriate erosion control system should be inshdled.
This system should collect and filter all surface run offthrough either silt fencing or a series ofproperlyplaced
and secured straw bales. We anticipate a system of berms and drainage ditches around construction areas will
provide an adequate collection system. If silt fencing is selected as a filter, this fencing fabric should meet the
' requirements of W SDOT Standard Specification 9-33.2 Table 3. 1n addifion, silt fencing should embed a
minimum of 6 inches below existing grade. If straw baling is used as a filter, bales should be secured [o the
ground so that they will not shift under the weight of retained water. Regardless of the silt filter selected, an
' erosion control system requires occasional observation and maintenance. Specifically, holes in the filter and
areas where the filter has shifted above ground surface should be replaced or repaired as soon as they are
identified.
' Temporary Drainaee: We recommend intercepting and diverting any potential sources of surface or
neaz-surface water within the construction zones before stripping begins. Because the selecfion of an
appropriate drainage system will depend on the water quanfity, season, weather conditions, constmction
January 5, 2007 E3RA, Inc.
TOfi397 / Yelm Dental
sequence, and contractor's methods, Final decisions regazding drainage systems are best made m the field at the
time of construction. Based on our current understanding of the construction plans, surface and subsurface
conditions, we anticipate that curbs, beans, or ditches placed around the work aeeas will adequately intercept
surface water runoff.
Clearine and S[rimoinn: After surface and neaz-surface water sources have been controlled, the construction
areas should be cleazed and stripped of all duff, and topsoil. Om explorations indicate that athickness of/: to
1 foot of topsoil will be encountered across the site. Also, it should be realized that if the stripping operation
proceeds during wet weather, a generally greater snipping depth might be necessary to remove disturbed
moisture-sensitive soils; therefore, stripping is best performed during a period of dry weather.
Site Exoavations: Based on our explorations, we expect that site excavations will encounter loose soils that
can be easily excavated by conventional earth working equipment.
Dewaterine: We do not anticipate dewatering to be necessary on this project.
Temporarv Cut Slopes: All temporary soil slopes associated with site cutting or excavations should be
adequately inclined to prevent sloughing and collapse. Temporary cut slopes in site soils should be no steeper
than 1'/: H:1 V, and should conform to WISIIA regulations.
Subemde Comnac5on: Exposed subgrades for footings and floors should be compacted to a fora, unyielding
state before new concrete or fill soils aze placed. Any localized zones of looser granulaz soils observed within
a subgrnde should be compacted to a density commensurate with the surrounding soils. 1o contrast, any
organic, soft, or pumping soils observed within a subgrade should be overexcavated and rephrced with a
suitable sWCtural fill material.
Site Fillina: Our conclusions regarding the reuse of on-site soils and our comments regarding wet-weather
filling aze presented subsequently. Regardless of soil type, all fill should be placed and compacted according
to our rewmmendations presented in the Structural Fill section of this report Specifically, building pad fill
soil should be compacted to a uniform densiTy of at (east 95 percent (based on ASTM:D-1557).
On-Site Soils: We offer the following evaluation ofthese on-site soils in relation to potential use as structural
fill:
Surficia! Sod and To soil: The sod and topsoil mantling the site is not suitable for use as
structural fill under any circumstances, due [o high organic content. Consequently, these
materials can be used only for non-structural purposes, such as in landscaping areas.
Black Ash: The black silty sandy gravel that underlies the site is currently near optimum
moisture content end might possibly be reused as structural fill, depending on conditons at
time of construction. It is more moisture sensifive then the outwash below and will be difficult
[o reuse during wet weather conditions.
Glacial Outwash: The sandy gravel with cobbles and boulders [hat underlies the site is
currently near optimum moisture content and can be reused as structural fill. This soil is less
moisture sensitive and can likely be reused in wet weather conditions.
4.2 Spread Footin¢s
In our opinion, conventional spread footings will provide adequate support for the proposed structure ff [he
subgmdes are properly prepared. We offer the following comments and recommendations for purposes of
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January 5, 2007
706397 / Yelm Dental
E3RA. Inc.
footing design and construction.
Footine Depths and Widths: For frost end erosion protection, the base of all extuior footings should bear at
least 24 inches below adjacent outside grades. To limit post-construction settlements, continuous (wall) and
isolated (column) footings should be at least 18 and 24 inches wide, respectively.
Bearine Snberades and Bearinn Pressures: The native ashy layer and glacial ou[wash underlying [he proposed
building footprint at subgmde elevations will adequately support spread footings. In general, before footing
concrete is placed, any localized zones of loose soils exposed across the footing subgrades should be
compacted to a fum, unyielding condition, and any localized zones ofsoft, organiq or debris-laden soils should
be over-excavated and replaced with suitable stmcmral fill.
Suberade Observation: All footing subgrades should consist of either firm, unyielding, native soils or suitable
stmctural fill materials. Footings should never he tact atop loose, soft, or frozen soil, slough, debris, existing
uncontrolled fill, or surfaces covered by standing water. We recommend that the condition of all subgrades be
observed by an E3RA representative before any concrete is placed.
Bearine Pressures: In our opinion, for static loading, footings that bear on properly prepared subgmdes can be
designed forthe maximum allowable soil bearing pressures of 2500 psf. A one-third increase in allowable sail
bearing capacity maybe used for short-term loads created by seismic or wind related activities.
Foctine Settlements: We estimate that total post-conshuction settlements of properly designed footings
bearing on properly prepazed subgmdes will not exceed ]inch. Differential settlements for comparably loaded
elements may approach one-half of this value over horizontal distances of approximately 50 feet.
Footine and Stemwall Backfill: To provide erosion protection and lateral load resistance, we rewmmend that
all footing excavations be bacld-filed on both sides of the footings, retaining walls, and stemwalls after the
concrete has cured. Either imported structural fill or non-organic on-site soils can be used for this purpose,
contingent on suitable moisture content at the time of placement. Regardless of soil type, all footing backfill
soil should be compacted to a densiTy of m least 90 percent (based on ASTM:D-1557).
fxteml Resistance: Footings that have been properly backfilled as recommended above will resist lateral
movements by means ofpassive earth prssswe and base friction. We recommend using an allowable passive
earb pressure of 300 psf for the granular backfill. We recommend an allowable base friction coefficient of
0.35 for granular soils.
4.3 Slab-On-Grade Floors
Tn our opinion, soil-supported slab-on-gade floors can be used in the proposed smrcmre if the subgrades are
properly prepared. We offer the following comments and recommendations concerning slabbn-gradefloors.
Floor Subbase: Shuctural fill subbases do not appeazto be needed under soil-supported shdwn-grade floors,if
the existing native subgrade can be thoroughly compacted. If subgmde compaction is not feasible, we
rewmmend that granular fill be placed to a depth of 12 inches below finish subgmde.
Canillarv Break and Vapor Barrier. To retard the upward wicking of groundwater beneath the floor slab in
areas where moismre sensitive floor coverings will be used, such as offices, we recommend that a capilhvy
break be placed over the subgrade. Ideally, this capillary break would consist of a 4-inch-thick layer of pea
gravel or other clean, uniform, well-rommded gavel, but clean angular gavel can be used if it adequately
prevents capillary wicking. Tn addition, a layer of plastic sheeting (such as Crossmff, Visqueen, or Moistop)
should be placed over the capillary break [o serve as a vapor barrier. During subsequent casting of[he concrete
slab, the contractor should exercise care to avoid puncturing this vapor barrier.
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January 5, 2007 E3RA, Inc.
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4.4 Drainage Systems
W e offer the following recommendations and comments for drainage design for construction purposes.
Perimeter Drains: We recommend that the buildings be encircled with a perimeter drain system to collect
seepage water. This drain should consist ofa 4-inch-diameter perforatedpipe withinanenvelope ofpea gravel
or washed rock, extending a[ least 6 inches on all sides of the pipe. The gravel envelope should be wrapped
with filter fabric to reduce the migration offines from the surrounding soils. Ideally, the drain invert would be
installed no more than 8 inches above the base of the perimeter footings.
Subtloor Drains: Because floor subgrades will on a granular material, we do not recommend the use of
subfloor drains.
Dischazee Considemtiops: ff possible, all perimeter drains should duohmge to a suitable dishearge location.
Runoff Water: Roof-mnoff and surface-runoff water should not dischazge into the perimeter drain system.
Instead, these sources should dischazge into separate trghtline pipes and be routed away from the buildingto a
storm drain or other appropriate location.
Grading and Capping: Final site grades should slope downwazd away from the building so that mnoff water
will flow by gravity to suitable collection points, rather than ponding neaz the building. Ideally, the area
surounding the building would be capped with concrete, asphalt, or low-permeability (silty) soils to minimize
or preclude surface-water infiltration.
4_5 Asphalt Pavement
Since asphaltic pavements will be used for the parking area and, possibly, driveways, we offer the following
comments and recommendations for pavement desigo and constmction.
Subemde Preparation: All soil subgrades should be thoroughly compacted, dten proof-rolled wittt a loaded
dump track or heavy compactor. Any localized canes ofyielding subgrade disclosed dining this proof-rolling
operation should be over excavated to a maximum depth of 12 inches and replaced with a suitable stmctuml
fill material.
Pavement Materials: For the base course, we recommend using imported crushed rock. Native materials shall
be adequate as a subbase.
Conventional Asphalt Secfions: A wmentional pavement section typically comprises an asphalt concrete
pavement over a crushed rock base course. Using the estimated design values stated above, we recommend
using [he following wnventional pavement sections:
Miuunum Thickness
Pavement Course Parking Areas High Tmi<c and Driveway
Areas
Asphalt Concrete Pavement 2 inches 3 inches
Crashed Rock Base 4 inches 6 inches
Granular Fill Subbase (if needed) l2 inohes 12
Compaction and Observation: All subbase and base course material should be compacted to at least 95 percent
January 5, 2007 E3R4, Inc.
' T06397 / Yelm Dental
of the Modified Proctor maximum dry density (ASTM D-1557), and all asphalt concrete should be compacted
' to a[ least 92 percent of dre Rice value (ASTM D-2041). We recommend that an E3RA representative be
retained to observe the compaction of each course before any overlying layer is placed. For the subbase and
pavement course, compaction is best observed by means of frequent density testing. For the base cowse,
methodotogy observations and hand-probing are more appropriate than density testing.
Pavement Life and Maintenance: No asphaltic pavement is maintenance-free. The above described pavement
sections present our minimum recommendations for an average level of performance during a20-year design
life; therefore, an average level of maintenance will likely be requited Furthermore, a 20-year pavement life
typically assumes that an overlay will be placed after about 10 years. Thicker asphalt and/or thicker base and
subbase courses would offer better long-term performance, but would cost more initially; thinner courses
' would be more susceptible to "alligator" cracking and other failure modes.. As such, pavement design can be
considered a compromise between a high initial cost and low maintenance costs versus a low initial cost and
higher maintenance costs.
' 4b Structural Fill
The teen "s[mctmal fill" refers to any placed under founda5ons, retaining walls, slab-on-grade floors,
sidewalks, pavements, and other structures. Our comments, conclusions, and recommendations concerning
stmctwal fill aze presented m the following paragraphs.
Materials: Typical structural fill materials include clean sand, gravel, pea gravel, washed rock, crashed rock,
' well-graded mixtwes of sand and gravel (commonly called "gravel borrow" or "pit-run"), and miscellaneous
mixmres of silt, sand, and gravel Recycled asphalt, concrete, and glass, wNch are derived from pulverizing
the parent materials, are also potentially useful as s[mcmral fill in certain applications. Soils used for strmctural
' fill shouldnot contain any organic matter or debris, noranyindividual particles greater than about6 inches in
diameter.
' Fill Placement: Clean sand, granulithic gravel, crushed rock, soil mixtures, and recycled materials should be
placed in horizontal lifts not exceeding 8 inches m loose thickness, and each lift should be thoroughly
compacted with a mechanical compactor.
I Comuacfion Criteria: Using the Modified Proctor test (ASTM:D-1557) as a standard, we recommend that
stmchual fill used for various on-site applications be compacted to the following minimum densities:
Fill Application Minimum
Compaction
Footing subgade and bearing pad 95 percent
Foundation backfill 90 percent
Slab-on-grade floor subgrade and subbase 9S percent
Pavement Subgrade (upper 2 feet) 95 percent
Pavement Subgrade (below 2 feet) 90 percent
Suberade Observation and Commaction Testine: Regazdless ofmaterial or location, all swctural fill should be
placed over fora, unyielding subgrades prepared N accordance with the Site Preparation section ofthis report.
The condifion of all subgrades should be observed by geotechnical personnel before filling or conslmc6on
begins. Also, fill soil compaction should be verified by means of in-place density tests performed during fill
placement so that adequacy of soil compaction efforts may be evaluated as earthwork progresses.
' January 5, 2007 E3RA, lnc.
' T06397 / Yelm Dental
Soil Moisture Considerations: The suimbility of soils used for stmcmral fill depends primarily on their
' grain-size distribution and moisture content when they are placed. As the "fines" content (that soil fraction
passing the U.S. No. 200 Sieve) increases, soils become more sensitive to small changes in moismre content.
Soils containing mare than about 5 percent fines (by weight) cannot be consistently compacted to a firm,
~' unyielding condition when the moisture content is more than 2 percentage points above or betow optimum.
For fill placement during wet-weather site work, we recommend using "clean" fill, which refers to soils that
have a fines content of 5 percent or less (by weight) based on the soil fraction passing the U.S. No. 4 Sieve.
' S.0 RECOMMENDED ADDITIONAL SERVICES
Because the future performance and integrity of the structural elements will depend largely on proper site
preparation, drainage, fill placement, and construction procedures, monitoring and testing by experienced
' geotechnical personnel should be wnsidered an integra(part of the construction process. Consequently, we
recommend that E3RA be retained to provide the following post-report services:
' Review all consWCtion plans and specifications to verify that our design criteriapresented in
this report have been properly integrated into the design;
• Prepare a letter addressing relevant review comments (if required by the City of Yelm);
• Check all completed subgrades for footings and slab-on-grade floors before wncrete is
' ponied, in order to verify their bearing capacity; and
• Prepare apost-construction letter summarizing all field observations, inspections, and test
results (if required by the CiTy of Sumner).
6.0 CLOSURE
The conclusions and rewmmenda[ions presented in this report are based, m part, on the explorations Nat we
observed for this study; Nerefore, if variations m Ne subgrade wnditions are observed az a later time, we may
need to modify this report to reflect Nose changes. Also, because Ne Cutme performance and integrity of the
project elements depend largely on proper initial site preparation, drainage, and construction procedures,
monitoring and testing by experienced geotechnical persomel should be considered an integral part of the
cons[mctlon process. E3RA is available to provide geotecbnical monitoring of soils Nroughout constmction.
January 5.2007 E3RA, Inc.
706397 / Yelm Dental
Weappreciatethe opportunity to be ofservice on this project. if you have any questions regarding this report
or any aspects of the project, please feel free to contact our office.
Sincerely,
E3RA, Inc.
Casey R. Lowe, E.LT.
Staff Engineer
CRL/JEB
Enclosures: Figure 1 - Location Mop
Figure 2 - Site & Exploration Plan
Attachment: Test Pit Logs TP-7 Through TP-3, Sieve Amlysis
0 3- ~ tr- c~-
Sames E Brigham, P.E.
Principal Engineer
January 5, 2007
706397 / Yelm Dental
E3RA, Inc.
TEST PIT LOGS -Yelm Deutal Office
Depth (feed Material Description
Test Pit TP-1
Location: Pazking at existing dental of5ce
Approxunate ground surface elevation: Unlmown
0.0 - 0.7 Crushed rock
0.7 - 2.0 Medium dense, moist, black ash silty sandy gravel with boulders and cobbles (SP-SM)
2.0 - 9 5 Medium Dense, moist, tan sandy gravel w/si1S cobbles, and boulders (SP).
Test pit terminated at approximately 9.5 feet
Moderate caving observed at 4.5 feet
No groundwater or mottling mted
Deo[h ffeetl
Material Description
Test Pit TP-2
Location: Existing home front yard
Approximate ground surface elevation: Unknown
0.0-0.5 Top Soil
0.7 - 2.5 Medium dense, moist, black ash silty sandy gravel with boulders and cobbles (SP-SM)
2.5 -10.0 Medhrm Dense, moist, tan sandy gravel w/silt, cobbles, and boulders (SP).
Test pit terminated at approximately 10 feet
Moderaze caving observed at 5 fee[
No gromdwater or mottling noted
Depth (feed
Material Description
Test Pit TP-3
Location: Existing home backyard
Approximate ground surface elevation: llnlmown
0.0-0.6 Crushed rock
0.6 - 2.0 Medium dense, moist, black ash silty study grovel w/boulders and cobbles (SP-SM)
2.0 - 5.5 Medium Dense, moist, tan sandy grovel with silt, cobbles, and boulders (SP).
5.5 - 10.0 Medium Dense, tan sandy graveVgmvelly sand (SP).
Test pit terminated at approx®ateTy 10 feet
Slight caving observed at 5.5 feet
No groundwater or mottling doted
Date Excavated: 11/I8/O6
Sample No.
S-I
S-2
Samole No.
S-I
Semple No.
S-I
Logged by: CRL
Particle Size Analysis Summary Data
Joh Name: Yelm Dental Office
Jab Number: T06397
Tested ByALH
Date: 11/20/06
Boring #: Perc #2
Sample #'. S-1
Depth: 5'
Moisture Content (%) 5.1
Sieve Size Percent
Passing(%)
3.0 in. 75.0 100.0
1.5 in. 37.5 78.5
3/4 in. 19.0 56.0
3/6 in. 9.5-mm 3fi.fi
No.4 4.75-mm 30.1
No. 10 2.00-mm 10.5
No. 20 .850-mm 9.4
No. 40 (.425~mm) 7.7
No. 60 .250-mm 6.2
No. 100 .150-mm 5.5
No. 200 .075-mm 5.2
LL
PI
D10 1.35
D30 4.74
Dfi0 21.42
Cc 0.78
Cu 15.92
Size Fraction Percent By
Weight
Coarse Gravel 44.0
Fine Gravel 26.0
Coarse Sand 19.5
Medium Sand 2.9
Fine Sand 2.5
Fines 5.2
Total 100D
ASfM DaglflcaG00
Group Name Brawn poorly graded gravel with silt and santl
Symbol (GP-GM)
E ~ ~~ Figure
Soil Classification Data Sheet
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APPENDIX D
PRELIMINARY STORM DRAINAGE CALCULATIONS
I
7r ~~ .
StormTech Routing Summary
10o Yr
PeakO = 0.4912 cfs
Peak Out Q: 0.1373 cfs
Peak Stg: 103.50 ft
Active Vol: 947.61 cf
Project Precips
[z yr] z.so in
[5 yr] 0.00 in
[10 yr] 3.50 in
[25 yr] 0.00 in
[100 yr] 4.50 in
[6 mo] 1.80 in
HydID Peak O
------- (cfs)
100 yr Out 0.14
Drainage Area: Onsite
Hyd Method: SBUH Hyd
Peak Factor: 484.00
Storm Dur: 24.00 hrs
Area
Pervious 0.1900 ac
Impervious 0.3700 ac
Total 0.5600 ac
Supporting Data:
Pervious CN Data:
Landscaping
Impervious CN Data:
Pavement and Sidewalks
Building Roof
Pervious TC Data:
Flow type: Description:
Fined Assume 5 min
Impervious TC Data:
Flow type: Description:
Fined Assume 5 min
BasinlD Peak O
------- (cfs)
Onslte 0.4912
Onsile 0.3632
Onsile 0.2393
Onsite 0.1568
Peak T Peak Vol Cont Area
(hrs) (ac-ft) (ac)
7.00 0.1701 0.5600
Loss Method: SCS CN Number
SCS Abs: 0.20
Intv: 10.00 min
CN TC
80.00 0.08 hrs
98.00 0.08 hrs
80.00 0.1900 ac
98.00 0.2400 ac
98.00 O.i300 ac
Length: Slope:
0.00 ft 0.00
Length: Slope:
o.oo n o.oo r
Peak T Peak Vol Area
(hrs) (ac-ft) ac
8.00 0.1704 0.56
8.00 0.1266 0.56
8.00 0.0641 0.56
6.00 0.0556 0.56
Coeff: Travel Time
5.0000 5.00 min
Coeff: Travel Time
5.0000 5.00 min
Method Raintype Even[
/Loss
SBUH/SCS TYPEIA 100 yr
SBUH/SCS TYPEIA 10 yr
SBUH/SCS TYPEIA 2yr
SBUH/SCS TYPEIA 6mo
w~smai~,~r~gocao~oteaz-moat', oamonoade~~so~m~caia~oea<zareiimcaimo~ ini
BCRA~I
Node ID: StormTech
Desc: Manhole structure
Start EI: 100.0000 ft
Contrib Basin:
Stage Input Volume
100.00 0.00 cf 0.00 cf
100.50 71.00 cf 71.00 cf
103.00 876.00 cf 876.00 cf
103.50 947.00 cf 947.00 cf
Based on 14 StormTech ch ambers.
StageStorge Table for node StormTech
Stage Vol Vol
(it) (cf) (ac-fp
100.00 0.00 0.0000
100.10 14.20 0.0003
100.20 28.40 0.0007
100.30 42.60 0.0010
100.40 56.80 0.0013
100.50 71.00 0.001fi
700.60 103.20 0.0024
100.70 13s.ao a.ooal
looso 1s7so o.oo3e
100.90 199.80 0.0046
101.00 232.00 0.0053
101.10 264.20 0.0061
1o1.zo zss.a6 o.oos6
101.30 328.60 0.0075
101.40 380.80 0.0083
101.50 393.00 0.0090
1o1so a2s.zo c.oosfi
m1.79 4szao o.olos
101.80 489.fi0 0.0112
Maz EI: 103.5000 ft
Contrib Hyd:
Volume
0.0000 acft
0.0016 acft
0.0201 acft
0.0217 acft
Stage Vol Vol
(ft) (cf) (ac-ft)
101.90 521.80 0.0120
102.00 s54.00 0.0127
102.10 586.20 0.0135
102.20 618.40 0.0142
102.30 650.60 0.0149
102.40 682.80 0.0157
102.50 715.00 0.0164
lozso 747.za o.o17z
lozao ns.aa o.o17s
102.80 811.60 0.0186
102.90 843.80 0.0194
103.00 876.00 0.0201
103.10 890.20 0.0204
103.20 904.40 0.0208
103.30 918.60 0.0211
103.40 932.80 0.0214
103.50 947.00 0.0217
X,\Slutllm\Clvll\Od~\0644NWays Danlal\Deggn\Slwm\COlcs\062YLPreAmCalcs.tloc 2/II
L/
StormSHEDCalculalians lob NO/ProlecC 06242 today's Dental Date: Il V/0] By'.1G
Control Structure ID: ChamberBottom -Stage Discharge rating curve
Descrip: Multiple Orifice
Start EI Maz EI Increment
100.0000 ft 103.5000 ft 0.10
Sfage Discharge
100.0000 ft 0.1373 cfs
103.5000 ft 0.1373 cfs
Based on 14 StormTech chambers.
Stage-Discharge Table for control: ChamberBottom
Slage Discharge Stage Discharge
(ft) (cfs) (fq (cfs)
100.00 0.1373 101.90 0.7373
100.10 0.13]3 102.00 0.13]3
100.20 0.1373 102.10 0.13]3
100.30 0.1373 102.20 0.1373
700.40 0.13]3 102.30 0.13]3
100.50 0.1373 102.40 0.1373
100.60 0.13]3 102.50 0.7373
100.70 0.1373 102.60 0.13]3
100.80 0.1373 102.]0 0.7373
100.90 0.13]3 702.80 0.1373
101.00 0.1373 102.90 0.13]3
101.10 0.13]3 103.00 0.1373
101.20 0.13]3 103.10 0.13]3
101.30 0.1373 103.20 0.13]3
101.40 0.1373 103.30 0.1373
101.50 0.1373 103.40 0.1373
101.60 0.7373 103.50 0.7373
101.70 0.13]3
101.8(1 0.1373
x'.xswaio:xcrvlnonaoTOazaz-ioeay:~amaixoeagnast«mxcai~xmzazPrenmcai~ao~ snt
Number of chambers - 14
gelds in the stnne (porosity,- 0.39 3tormTech•
~.~•„o~.a~,~,
~„
Subsurface Stormwarer Management"
StormTech SC 740 Incremental Storage Volumes
I '
Height of Incremental Incremental Cumulative Cumulative
System (in) Chamber (ft') Ch & St (ft') I Chamber (ft') System (ft')
ia4 ` _ a " '; Q 86 y ' "69 35 ~ 971
0:$6 ~ 685.1 959
42 0 0.85 67.66 947
41 0 0.85 66.81 935
40 0 0.85 65.97 924
39 0 0.85 65.12 912
38 0 0.85 64.28 900
37 0 0.85 63.43 888
3fi 0.05 0.88 62.59 876
35 0.16 0.96 61.71 864
34 0.28 1.04 60.75 850
33 0.60 1.27 59.70 836
32 0.80 1.41 58.44 818
31 0.95 1.51 57.03 798
30 1.07 1.60 55.52 777
29 1.18 1.67 53.92 755
28 1.27 1.73 52.25 732
27 1.36 1.79 50.52 707
26 1.45 1.86 48.73 682
25 1.52 1.91 46.8fi 656
24 1.58 1.95 44.95 629
23 1.64 1.99 43.00 602
22 1.70 2.03 41.00 574
21 1.75 2.07 38.97 546
20 1.80 2.11 36.90 517
19 1.85 2.14 34.79 487
18 1.89 2.17 32.65 457
17 1.93 2.20 30.48 427
16 1.97 2.23 28.28 396
15 2.01 2.25 26.05 365
14 2.04 2.28 23.80 333
13 2.07 2.30 21.52 301
12 2.10 2.32 19.22 269
11 2.13 2.34 16.90 237
10 2.15 2.35 14.57 204
9 2.18 2.37 12.21 171
8 2.20 2.38 9.84 138
7 2.21 2.39 7.46 104
6 0 0.85 5.07 71
5 0 0.85 4.23 59
4 0 0.85 3.38 47
3 0 0.85 2.54 35
2 0 0.85 1.69 24
1 0 0.85 0.85 12
Total Chamber Storage=45.9 R' 67.66
Calculations are based upon a 6 inch stone base under the chambers
Corporate Office
20 Beaver Roatl Wethersfield, CT 06709 (Off8f092-2694 Fax (666t 32&0401
I' x~xsma~xa.axoacaoxoaz<amaay:_oemanoesgo~s~onnxcm=:xoazazrra~mcai=: m= any
~_
S~ormSHED CalculaROru Job NO/Protect 06242 iotlav's Dental Dot
Node ID: YelmStormTech
Desc: Manhole structure
Start EI: 100.0000 ft Max EI: 103.5000 ft
Contrib Basin: Contrib Hyd:
Stage Input Volume Volume
100.00 0.00 cf 0.00 cf 0.0000 acft
100.50 34.00 cf 34.00 cf 0.0008 acft
103.00 341.00 cf 341.00 cf 0.0078 acft
103.50 374.00 cf 374.00 cf 0.0086 acft
Stage-Storge Table for node YelmStormTech
Stage Vol Vol Stage Val Vol
(ft) (cf) (ac-f[) (fp (cf) (ac-ft)
100.00 0.00 0.0000 101.90 205.92 0.0047
100.10 6.80 0.0002 102.00 218.20 0.0050
100.20 13.fi0 0.0003 102.70 230.48 0.0053
100.30 20.40 0.0005 102.20 242.76 0.0056
100.60 27.20 0.0006 702.30 255.06 0.0059
100.50 34.00 0.0008 102.40 267.32 0.0061
100.60 4628 00011 102.50 279.60 0.0064
100.70 58.56 0.0013 102.60 291.88 0.0067
700.80 70.84 0.0016 102.70 304.16 0.0070
100.90 83.12 0.0019 102.80 316.44 00073
101.00 95.60 0.0022 102.90 328.72 000]5
101.10 107.fi8 0.0025 10300 341.00 0.0078
101.20 119.96 0.0028 103.10 347.fi0 0.0080
101.30 132.24 0.0030 103.20 356.20 0.0081
101.40 144.52 0.0033 103.30 360.80 0.0083
101.50 756.80 0.0036 103.40 367.40 0.0084
101.60 169.08 0.0039 103.50 374.00 0.0086
101.70 181.36 0.0042
101.80 193.64 0.0044
.~ ~
\Sludlos\C'rvp\g~\OdbDlodays_Den~al\Design\Stpm\Calcs\06242PMImCaIrs.MC 5/I1
'~~
9ortnSHED Calculatons JOb NO/ProlecL 064d2iaday's Dental oate: l/IJ/DJ By: JG
Control Structure ID: YelmBottom -Stage Discharge rating curve
Descrip: Multiple Orifice
Start EI Max EI Increment
100.0000 ft 103.5000 fl 0.10
Stage Discharge
100.0000 ft 0.0514 cfs
103.5000 ft 0.0514 cfs
Stage-Discharge Table for control: YelmBottom
Stage Discharge Stage Discharge
(ft) (cfs) (fl) (cfs)
1no.oa o.os14 1ot9o o.os14
100.10 0.0514 102.00 0.0514
100.20 0.0514 102.10 0.0514
100.30 0.0514 102.20 0 0514
100.40 0.0514 102.30 0.0514
100.50 0.0514 102.40 0.0514
100.60 0.0514 102.50 0.0514
100.70 0.0514 102.60 0.0574
1oo.aa c.osla 1nz.7o c.asla
ma.9o o.o51a mz.ac o.o51a
101.00 0.057d 102.90 0.0514
101.10 0.0514 103.00 0.0514
101.20 0.0514 103.70 0.0514
101.30 0.0514 103.20 0.0514
101.40 0.0514 103.30 0.0574
101.50 0.0514 103.40 0.0514
101.60 0.0514 103.50 0.0514
101.70 0.0514
101.60 0.0514
k\9utllm\CI l\OdOJ]\M]dNMays_Den~al\OeslBn\S~am\COlcs\06P4PPiellmCalo dm 6lll
Number of chambers - 5 '
Voids in the stone (porosity)- 0 40 StormTech°
na~,~.e.,~~,~.~~
Subsurface Stormwaler Management"
StormTech SC 740 Incremental Storage Volumes
Height of Incremental Incremental Cumulative Cumulative
System (iN Chamber (ftst Ch & St (ftsl Chamber (fta) System (ftst
~
~
~
~~
~ '' Ftp 1'[a3 + ;;
~
~ '"r 3'~7~i5 .$@.~
~
`
`
°
~ °'
' 1 13 76;02. ~. s
$
8
b
,
+, .
= „
.r .
42 0 1.13 74.90 374
41 0 1.13 73.77 369
40 0 1.13 72.64 363
39 0 1.13 71.52 358
38 0 1.13 70.39 352
37 0 1.13 69.26 346
36 0.05 1.16 68.14 341
35 0.16 1.22 66.98 335
34 0.28 1.30 65.75 329
33 0.60 1.49 64.46 322
32 0.80 1.61 62.97 315
31 0.95 1.70 61.36 307
30 1.07 1.77 59.66 298
29 1.18 1.84 57.89 289
28 1.27 1.89 56.05 280
27 1.36 1.94 54.17 271
26 1.45 2.00 52.23 261
25 1.52 2.04 50.23 251
24 1.58 2.08 48.19 241
23 1.64 2.11 46.11 231
22 1.70 2.15 44.00 220
21 1.75 2.18 41.85 209
20 1.80 2.21 39.67 198
19 1.85 2.24 37.47 187
18 1.89 2.26 35.23 176
17 1.93 2.29 32.96 165
16 1.97 2.31 30.68 153
15 2.01 2.33 28.36 142
14 2.04 2.35 26.03 130
13 2.07 2.37 23.68 118
12 2.10 2.39 21.31 107
1 t 2.13 2.41 18.92 95
10 2.15 2.42 16.51 83
9 2.18 2.43 14.09 70
8 2.20 2.45 11.66 58
7 2.21 2.45 9.21 46
6 0 1.13 6.76 34
5 0 1.13 5.63 28
4 0 1.13 4.51 23
3 0 1.13 3.38 17
2 0 1.13 2.25 11
1 0 1.13 1.13 6
Total Chamber Storage=45,9 k' 74.90
Corporate Office
20 Beaver Roatl Wethersfieltl, CT 06109 (BBBE892-2694 Fax (866) 328-8401
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SmrmSHFO Calculations JOb NO./ProiecL O64G2 iabay's Dental Date 1/VIp] ByJG
JefferStormTechRouling Summary
100 yr
PeakQ = 0.1204 cfs
Peak Out O: 0.0411 cfs
Peak Slg: 102.03 ft
Active Vol: 177.80 cf
Project Precips
[2 yr] 2.50 in
[5 yr] 0.00 in
[10 yr] 3.50 in
[25 yr] 0.00 in
[100 yr] 4.50 in
[6 mo] 1.80 in
HydID PeakQ Peak T Peak Vol Cont Area
------- (cfs) (hrs) (ac-h) (ac)
100 yr Out JF 0.04 7.33 0.0417 0.1300
Drainage Area: Jefferson Frontage
Hyd Method: SBUH Hyd Loss Method: SCS CN Number
Peak Factor: 484.00 SCS Abs: 0.20
Storm Dur: 24.00 hrs Intv: 10.00 min
Area CN TC
Pervious 0.0300 ac 80.00 0.08 hrs
Impervious 0.1000 ac 98.00 0.08 hrs
Total 0.1300 ac
Supporting Data:
Pervious CN Data:
Landscaping 80.00 0.0300 ac
Impervious CN Data:
Pavement and sitlewalk 98.00 0.1000 ac
Pervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Fixed Assume 5 min 0.00 ff 0.00 % 5.0000 5.00 min
Impervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Fixed Assume 5 min 0.00 ft 0.00 % 5.0000 5.00 min
BasinlD Peak O Peak T Peak Vol Area Method Raintype Event
------- (cfs) (hrs) (ac-ff) ac /Loss
Jefferson Frontage 0.1204 B.00 0.0417 0.13 SBUH/SCS TYPEIA 100 yr
Jefferson Frontage 0.0905 8.00 0.0313 0.13 SBUH/SCS TYPEIA 10 yr
Jefferson Frontage 0.0611 8.00 0.0211 0.13 SBUH/SCS TYPEIA 2 yr
Jefferson Frontage 0.0411 8.00 0.0142 0.13 SBUH/SCS TYPEIA 6 mo
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BCRA~
NodelD:JefferStormTech
Desc: Manhole structure
Start EI: 100.0000 ft Max EI: 103.5000 ft
Conirib Basin: Contrib Hyd:
Stage Input Volume Volume
100.00 0.00 cf 0.00 cf 0.0000 acft
100.50 27.00 cf 27.00 cf 0.0006 acft
103.00 273.00 cf 273.00 cf 0.0063 acft
103.50 300.00 cf 300.00 cf 0.0069 acft
Stage-Storge Table for node JefferStormTech
Slage Vol Val Stage Vol Vol
(ft) (cf) (ac-ft) (ft) (cf) (ac-fp
100.00 0.00 0.0000 101.90 164.76 0.0038
100.10 5.40 0.0001 102.00 774.60 0.0040
100.20 10.80 0.0002 102.10 184.44 0.0042
100.30 16.20 0.0004 102.20 194.28 0.0045
100.40 21.60 0.0005 102.30 204.12 0.004]
100.50 27.00 0.0006 102.40 213.96 0.0049
100.60 36.84 0.0008 102.50 223.80 0.0051
100.70 4fi.68 0.0011 102.60 233.64 0.0054
100.80 56.52 0.0013 10210 243.48 0.0056
700.90 66.36 0.0015 102.80 253.32 0.0058
101.00 76.20 0.0017 102.90 263.16 0.0060
101.10 86.04 0.0020 103.00 273.00 0.0063
101.20 95.88 0.0022 103.10 278.40 0.0064
101.30 105.72 0.0024 103.20 283.80 0.0065
101.40 115.56 0.0027 103.30 289.20 0.0066
101.50 125.40 0.0029 103.40 294.60 0.0068
101.60 135.24 0.0031 703.50 300.00 0.0069
101.70 165.08 0.0033
101.80 154.92 0.0036
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Control Structure ID: JefferBottom -Stage Discharge rating curve
Descrip: Multiple Orifice
Start EI Max EI Increment
100.0000 ft 103.5000 ft 0.10
Stage Discharge
100.0000 ft 0.0411 cfs
103.5000 ft 0.0411 cfs
Stage-Discharge Table for control: JefferBottom
Stage Discharge Stage Discharge
(ft) (cfs) (ft) (cfs)
100.00 o.oa11 miso c.oa11
loam o.oa11 10z.c0 o.a411
mo.zo o.oa11 mz.to o.oan
100.30 0.0411 102.20 0.0411
100.40 0.0411 102.30 0.0411
moss o.oa11 mz.aa o.oa11
100.60 0.0411 102.50 0.0411
700.10 0.0411 702.60 0.0411
1oo.eo o.oan mz.1o o.oa11
100.90 0.0411 102.80 0.0411
101.00 0.0411 102.90 0.0411
101.10 0.0411 103.00 0.0411
101.20 0.0411 103.10 0.0411
101.30 0.0411 703.20 0.0411
101.40 0.0411 103.30 0.0411
101.50 0.0411 103.40 0.0411
101.60 0.0411 103.50 0.0411
101.10 0.0411
m1.60 o.aa11
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Number of chambers - 4
Voitls in the stone (porosity) - 0.40 StormTech•
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Suhsutlace Stormwater Management`
StormTech SC 740 Incremental Storage Volumes
Height of Incremental Incremental Cumulative Cumulative
System (in) Chamber (ft') Ch & St (fta) Chamber (fta) System (fta)
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42 0 1.13 74.90 300
41 0 1.13 73.77 295
40 0 1.13 72.64 291
39 0 1.13 71.52 286
38 0 1.13 70.39 282
37 0 1.13 69.26 277
36 0.05 1.16 68.14 273
35 0.16 1.22 66.98 268
34 0.28 1.30 65.75 263
33 0.60 1.49 64.46 258
32 0.80 1.61 62.97 252
31 0.95 1.70 61.36 245
30 1.07 1.77 59.66 239
29 1.18 1.84 57.89 232
28 1.27 1.89 56.05 224
27 1.36 1.94 54.17 217
26 1.45 2.00 52.23 209
25 1.52 2.04 50.23 201
24 1.58 2.08 48.19 193
23 1.64 2.11 46.11 184
22 1.70 2.15 44.00 176
21 1.75 2.18 41.85 167
20 1.80 2.21 39.67 159
19 1.85 2.24 37.47 150
18 1.89 2.26 35.23 141
17 1.93 2.29 32.96 132
i6 1.97 2.31 30.68 123
15 2.01 2.33 28.36 113
14 2.04 2.35 26.03 104
13 2.07 2.37 23.68 95
12 2.10 2.39 21.31 85
11 2.13 2.41 18.92 76
10 2.15 2.42 16.51 fib
9 2.18 2.43 14.09 56
8 2.20 2.45 11.66 47
7 2.21 2.45 9.21 37
6 0 1.13 6.76 27
5 0 1.13 5.63 23
4 0 1.13 4.51 18
3 0 1.13 3.38 14
2 0 1.13 2.25 9
1 0 1.13 1.13 5
Total Chamber storage=45.9 it" /4.811
I Corporate Office
' 20 Beaver Road WethersfelQ CT 06109 (888)892-2fi94 Fax (866) 328-8401
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APPENDIX E
PRELIMINARY WATER QUALITY CALCULATIONS
I '
',, ~ V 1 ~ 1
SbrmSHED Calculations Job NO/Prolect'06242 totlay's Denlol Dote: I/I1/W By: iO
WATER QUALITY CALCULATIONS
Drainage Area: OnsiteWQ
Hyd Method: SBUH Hyd Loss Method: SCS CN Number
Peak Factor: 484.00 SCS Abs: 0.20
Storm Dur: 24.00 hrs Inlv: 10.00 min
Area CN TC
Pervious 0.1900 ac 80.00 0.08 hrs
Impervious 0.2400 ac 98.00 0.08 hrs
Total 0.4300 ac
Supporting Data:
Pervious CN Data:
Landscaping 80.00 0.1900 ac
Impervious CN Data:
Pavement and Sidewalks 98.00 0.2400 ac
Pervious TC Data:
Flow type: Description: Lenglh: Slope: Coeff: Travel Time
Fixed Assume 5 min 0.00 ft 0.00 % 5.0000 5.00 min
Impervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Fixed Assume 5 min 0.00 ft 0.00 % 5.0000 5.00 min
BasinlD Peak Q Peak T Peak Vol Area Method Raintype Event
------- (cfs) (hrs) (ac-ft) ac /Loss
OnsiteWQ 0.1056 600 00386 0.43 SBUHISCS TYPEIA 6mo
Qwo = 0.1056 cfs b Use 4 StormFilter cartridges.
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10/II
BCR,
1
1
1
Drainage Area: Yelm FrontageWQ
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Hyd Method: SBUH Hyd Lass Method: SCS CN Number
Peak Factor: 484.00 SCS Abs: 0.20
Sloan Dur: 24.00 hrs Inty: 10.00 min
Area CN TC
Pervious 0.0400 ac 80.00 0.08 hrs
Impervious 0.1600 ac 98.00 0.08 hrs
Total 0.2000 ac
Supporting Dala:
Pervious CN Data:
Landscaping 80.00 0.0400 ac
Impervious CN Data:
Pavement and Sidewalk 98.00 0.1600 ac
Pervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Fined Assume 5 min 0.00 ft 0.00% 5.0000 5.00 min
Impervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Fixed Assume 5 min 0.00 ft 0.00 % 5.0000 5.00 min
BasinlD Peak Q Peak T Peak Vol Area Method Raintype Event
------- (cfs) (hrs) (ac-ft) ac /Loss
Yelm Frontage 0.0653 8.00 0.0225 0.20 SBUHISCS TYPEIA 6 mo
Qwo = 0.0053 cfs b use 2 StormFilter cartridges
Drainage Area: Jefferson FrontageWQ
Hyd Method: SBUH Hyd Loss Method: SCS CN Number
Peak Factor: 484.00 SCS Abs: 0.20
Storm Dur: 24.00 hrs Intv: 10.00 min
Area CN TC
Pervious 0.0300 ac 80.00 0.08 hrs
Impervious 0.1000 ac 98.00 0.08 hrs
Total 0.1300 ac
Supporting Data:
Pervious CN Data:
Landscaping 80.00 0.0300 ac
Impervious CN Data:
Pavement and sidewalk 98.00 0.1000 ac
Pervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Fined Assume 5 min 0.00 ft 0.00 % 5.0000 5.00 min
Impervious TC Data:
Flow type: Description: Length: Slope: Coeff: Travel Time
Fixed Assume 5 min 0.00 fl 0.00 % 5.0000 5.00 min
BasinlD Peak Q Peak T Peak Vol Area Method Raintype Event
------- (cfs) (hrs) (ac-ft) ac /Loss
Jefferson Frontage 0.0411 8.00 0.0142 0.13 SBUH/SCS TYPEtA 6 mo
Qwo = 0.0411 cfs b use 2 StormFilte r cartridges
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