HomeMy WebLinkAboutMiscTECHNICAL INFORMATION REPORT
(FULL DRAINAGE REVIEW)
Shuttle Express Parking Lot
Parcel #: 3340406430
Addres.~: 800 SW 16'h Street, Renton, WA
August 2,20/3
Owner:
Peer Frank, LLC
A tin: Devin Sherrell
800 SW f(ih Street
Renton, WA 98057
Phone: (425) 98/-7069
OICIG
; [
For Submittal to
City of Renton
DAVIDO CONSULTING GROUP, INC.
CIVIL· STRUCTURAL· LAND USE
15029 Bothell Way NE, Ste 600
Lake Forest Park, WA 98155
Phone: 206,523,0024
Fax: 206,523.1012
PO Box 1132
Freeland, W A 98249
Phone: 360.331.4131
Fax: 360.331.7394
Technical Information Report
Shuttle Express Parking Lot-800 SW 16 th Street August 2, 2013
CERTIFICATE OF ENGINEER
The technical material and data contained within this report has been prepared by or under the
direction of the following registered professional engineer(s), licensed in accordance with the
laws of the State of Washington to practice in the State of Washington.
DavidQ Consulting Group, Inc.
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QUICK REFERENCE PROJECT INFORMA nON
General Project Information
r----------------------
I Project Description
I
Parcel #
Site Address
Parcel Size
Project Size
OwnerlDeveloper
Consulting Engineer
Drainage
Study Area
Drainage
Requirements
Tributary Drainage
Area & Land Cover
Summary
Soils
Drainage
Improv~ments .
ESC Measures
Davido Consulting Group, Inc.
T1R_Shuttle Express.doc
Construction of an approximately 15,000 SF porous asphalt
parking lot for Shuttle Express in Renton, W A.
3340406430
8()0. SW 16m St, Renton, W A
.-
141,425 SF (3.25 Acres)
:f3)82SF 0.01 Acres)
--------------
Peer Frank, LLC
Attn: Devin Sherrell
800 SW 16th Street
Renton, W A 98057
Phone: (425) 981-7069
Quin Clements, P.E. -Davido Consulting Group, Inc.
P.O. Box 1132
Freeland, W A 98249
Phone: (3601331-~ 131
---------------------------------
The study area is the site itself as no surface flow is leaving the
site or entering the site from adjacent properties.
Full Drainage Review Requirements per the 2009 King County
Surface Water Design Manual (KCSWDM) and City of Renton
Amendments to the KCSWDM (combination of which is
hereafter referred to as The Manual).
Predeveloped Conditions: ' Redeveloped Conditions:
Impervious = 8,880 SF Impervious = 25,439 SF
PGIS = 6,585 SF PGIS = 21,427 SF
Pervious Surface = 34,902 SF Pervious Surface = 18,343 SF
Total = 43,782 SF Total = 43,782 SF
._------
Geotechnical analysis and report completed by Nelson
. geotechnical Associate.s, Inc.
Low Impact Development (LID) Best Management Practices
(BMPs) are proposed comprised of porous asphalt.
ESC measures per Full Drainage Requirements
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Shuttle Express Parking Lot-800 SW 16 th Street August 2, 2013
TABLE OF CONTENTS
I. Project Overview ......................................................................................................... .5
1.1 General Description of Proposal ................................................................................... 5
1.2 Existing Site Conditions ............................................................................................... 6
1.3 Developed Site Conditions ............................................................................................ 6
1.4 Site Area and Size ofimprovements ............................................................................. 6
1.5 Disposition of Storm water before Project.. .................................................................... 7
1.6 Disposition of Stormwater after Project ........................................................................ 7
1.7 Soils ............................................................................................................................. 7
2. Conditions and Requirements Summary ....................................................................... 9
2.1 Core Requirement #1: Discharge at Natural Location ................................................... 9
2.2 Core Requirement #2: Off site Analysis ......................................................................... 9
2.3 Core Requirement #3: Flow Control ............................................................................. 9
2.4 Core Requirement #4: Conveyance System ................................................................... 9
2.5 Core Requirement #5: Erosion and Sediment Control ................................................... 9
2.6 Core Requirement #6: Maintenance and Operations .................................................... 1 0
2.7 Core Requirement #7: Financial Guarantees and Liability ........................................... IO
2.8 Core Requirement #8: Water Quality .......................................................................... 10
2.9 Special Requirement #1: Other Adopted Area-Specific Requirements ........................ 10
2.10 Special Requirement #2: Flood Hazard Area Delineation ............................................ 10
2.11 Special Requirement #3: Flood Protection Facilities ................................................... 10
2.12 Special Requirement #4: Source ControL ................................................................... 10
2. \3 Special Requirement #5: Oil Control .......................................................................... 10
2.14 Special Requirement #6: Aquifer Protection Area ....................................................... 10
3. Offsite Analysis .......................................................................................................... 11
4. Flow Control and Water Quality Facility Analysis and Design .................................... 11
4.1 Existing Site Hydrology .............................................................................................. 11
4.2 Developed Site Hydrology .......................................................................................... 11
4.3 Performance Standards ............................................................................................... 11
4.4 Flow Control System .................................................................................................. 12
4.4.1 KCRTS Modeling .................................................................................................. 12
4.5 Water Quality System ................................................................................................. 12
4.5.1 Soil Treatment Liner .............................................................................................. 12
5. Conveyance System Analysis and Design ................................................................... \3
5.1 Existing Conveyance .................................................................................................. 13
5.2 Proposed Conveyance ................................................................................................. 13
6. Special Reports and Studies ........................................................................................ 13
7. Other Permits .............................................................................................................. 14
8. CSWPPP Analysis and Design ................................................................................... 14
8.1 ESC Plan Analysis and Design ................................................................................... 14
8.2 Stormwater Pollution Prevention and Spill Plan Design .............................................. 15
9. Bond Quantities, Facility Summaries, and Declaration of Covenants .......................... 16
10. Operations and Maintenance Manual .......................................................................... 16
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APPENDICES
APPENDIX A Figure I -Technical Information Report (TIR) Worksheet
APPENDIX B Geotechnical Report
APPENDIX C Site Improvement Plans
APPENDIX D Temporary Erosion and Sediment Control Plan
APPENDIX E Operation and Maintenance
APPENDIX F Bond Quantity Worksheet
APPENDIX G Stormwater Facility Summary Sheet
APPENDIX H KCRTS Modeling Results
APPENDIX I Conveyance Calculations
LIST OF TABLES
August 2, 2013
TABLE I
TABLE 2
TABLE 3
Site Area and Size ofimprovements ..................................................................... 6
Facilities Summary ............................................................................................. 12
Proposed ESC Measures and Construction Sequencing ....................................... 15
LIST OF FIGURES
FIGURE I TIR Worksheet.. .............................................................. APPENDIX A
FIGURE 2 Site Location ....................................................................................................... .5
FIGURE 3 Drainage Basins, Subbasins, and Site Characteristics ............................................ 8
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1. PROJECT OVERVIEW
The project involves the construction of an approximately 15,000 SF porous asphalt parking lot
to the south ofthe existing Shuttle Express building at 800 SW 16 th Street in Renton,
Washington (see FIGURE 2). The project site is slightly over an acre in area and is a small
portion of a larger parcel. The project will adhere to the 2009 King County Surface Water
Design Manual (KCSWDM) as well as the 2010 City of Renton Amendments to the KCSWDM,
the combination of which is hereafter known as "The Manual". Given The Manual, the project is
subject to Full Drainage Review, as specified in Section 1.1 of The Manual.
This report follows the Technical Information Report (TIR) requirements for Full Drainage
Review per The Manual. The TIR worksheet is attached as FIGURE I in APPENDIX A.
FIGURE 2 Site Location
1.1 General Description of Proposal
The project involves the construction of an approximately 15,000 SF porous asphalt parking lot
with inmress from an existing driveway otT of SW 16'h Street and egress connecting directly to
SW 16' Street. The project will also include site drainage, grading, and landscaping. Frontage
improvements to SW 16 th Street, which includes an 8-foot landscape strip and 6-foot wide
sidewalk, are included in this project as well.
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1.2 Existing Site Conditions
The existing site is accessed via an asphalt driveway from SW 16 th Street. The existing site
conditions include a driveway and parking area to the east of the Shuttle Express building, lawn,
and trees. The majority of the area that will be disturbed will be the lawn area to the south of the
Shuttle Express building. However, a small portion ofthe existing asphalt parking area will be
replaced with porous asphalt. TABLE I summarizes the existing site land cover. The drainage
basin is the project limits itself as no offsite flow enters the site's drainage system.
1.3 Developed Site Conditions
The developed site conditions, shown in the project plans submitted under separate cover, will
include a new 15,000 SF porous asphalt parking lot to the south ofthe existing Shuttle Express
building. The new parking lot will be used for a combination of bus and employee parking.
Stormwater runoff from the developed site will infiltrate through the porous asphalt, which will
include a 6-inch thick storage layer of rock for stormwater storage. Overflow fur the permeable
pavement facility will be a catch basin conveyance system designed to capture and convey all
stormwaterto the City's system in SW 16th Street. TABLE I summarizes the developed site
conditions and land cover and the developed site drainage basin is shown in FIGURE 3.
1.4 Site Area and Size of Improvements
The pre-developed and developed site area and size ofimprovements are shown in FIGURE 3
and summarized in TABLE 1.
TABLE 1 Site Area and Size ofImprovements
Project Site Areas
Existing Developed
SF Acres SF Acres
Impervious Areas:
Concrete Walkway 1,900 0.04 1,900 0.04
Asphalt 6,585 0.15 6,559 0.15
Gravel 395 0.01
Porous Asphalt 14,868 0.34
Concrete Sidewalk 2,112 0.05
Total Impervious Surface 8,880 0.20 25,439 0.58
Total New/Replaced
Impervious Surface: 14,868 0.34
Total Pollution Generating
Impervious Surface: 6,585 0.15 21,427 0.49
Total New/Replaced Pollution
Generating Impervious
Surface: 14,868 0.34
Pervious Areas:
Landscaping 34,902 0.80 18,343 0.42
Total Pervious Surface 34,902 0.80 18,343 0.42
Total Project Site Area 43,782 1.01 43,782 1.01
The land cover areas in TABLE I were determined by area measurements in AutoCAD from a
topographic survey performed on May 15, 2013. As shown by TABLE 1, the developed site is
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adding 14,868 SF of new impervious surface. The porous asphalt parking lot will make up the
entirety of the impervious surface, therefore adding 14,868 SF of PGlS as well. These areas
represent the site coverage in the basin draining to the proposed permeable pavement facility.
1.5 Disposition of Stormwater before Project
As shown by TABLE I, the majority of the existing site coverage is grass. Any stormwater
runoff that does not infiltrate sheet flows southerly across the site into a catch basin near the
south property line. The catch basin connects to the City's storm system on the north side ofSW
16th Street.
1.6 Disposition of Stormwater after Project
The developed site stormwater will infiltrate through the porous asphalt where there will be a 6"
rock pocket underneath for storage. The permeable pavement facility is sized to handle all the
stormwater from a 100-year storm. Only during extreme events (greater than any event in the
available data in KCRTS), a rain on snow event for example, or if the permeable pavement gets
clogged and is unable to allow stormwater to infiltrate, will stormwater leave the site through an
overflow system. The overflow system will be comprised of new Type 1 catch basins with 8-12"
storm drain pipes connected to the City'S system at an existing Type 1 catch basin in the north
side ofSW 16'h Street (see APPENDIX C for the site improvement plans).
1.7 Soils
A geotechnical investigation was completed by Nelson Geotechnical Associates, Inc. (NGA).
The results ofthis investigation are summarized in a report dated June 21,2013; a copy ofthe
report is attached in APPENDIX B. The NGA report includes investigation findings and
recommendations for the stormwater infiltration system. NGA dug four test pits on June 3, 2013
to depths between 8.5 and 12.0 feet. In all four test pits topsoil and grass was underlain by
approximately 3.8 to 4.8 feet of medium dense to dense, brown gray fine sand with silt, trace
gravel and varying amounts of organics which is thought to be undocumented fill. Below the fill
layer is a loose/soft, iron-oxide stained, native alluvium soils layer. All four test pits were
terminated within the alluvium soils layer. NGA also conducted two on-site infiltration tests in
the parking lot area. The measured infiltration rates from the two tests were 6.92 and 13.84
inches per hour. However, based on their observations and the varying nature of the underlying
soils throughout the site, NGA recommended using a 0.5 inch per hour infiltration rate for
stormwater modeling.
The Manual requires a minimum of three feet of permeable soil below the bottom of an
infiltration facility, and at least three feet of separation from the bottom ofthe infiltration facility
to the maximum wet-season water table. The NGA geotechnical report states that because the
subsurface soils have a high silt content and indications of shallow groundwater, the site
subsurface soils are poorly suited for traditional stormwater infiltration trenches. However, NGA
does recommend the use of pervious pavement surfacing to allow runoff from the parking lot to
infiltrate into the granular fill layer found within the site. The full NGA report is attached in
APPENDIX B.
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FIGURE 3
Davjdo Consulting Group, Inc
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Drainage Basins, Subbasins, and Site Characteristics
(insert AutoCAD drawing Figure 3)
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Shuttle Express Parking Lot-800 SW 16'h Street August 2, 2013
2. CONDITIONS AND REQUIREMENTS SUMMARY
The project conditions and requirements were stipulated in the KCSWDM and by the City of
Renton Amendments to the KCSWDM. The project conditions and requirements are summarized
as follows:
~ The project is subject to Full Drainage Review requirements specified in Section 1.1.2 of
the Manual (>2,000 SF impervious surfaces).
~ The project is subject to Levell flow control (or Peak Rate Flow Control Standard).
~ The project is subject to basic water quality requirements (>5,000 SF new or replaced
POI S will be created).
The following sections address The Manual's core and special requirements.
2.1 Core Requirement #1: Discharge at Natural Location
The proposed drainage system has been sized to infiltrate the 100-year storm onsite. Therefore,
the proposed drainage system will emulate the natural pre-developed conditions of the site as
much as possible and the overflow entering the downstream drainage system will maintain the
natural drainage course from the site, thus satisfYing Core Requirement #1 of The Manual (see
Sections 1.5 and 1.6).
2.2 Core Requirement #2: OtTsite Analysis
Stormwater will be infiltrated onsite through a permeable pavement facility and the project will
not change the rate, volume, duration, or location of discharges to and from the site. Therefore,
the project is not required to submit an offsite analysis report based on exemption #3 on Page 1-
21 of the Renton Amendments to the KCSWDM.
2.3 Core Requirement #3: Flow Control
The proposed onsite infiltration facility infiltrates and detains 100% ofthe stormwater runoff
(based on full periods ofrecord/data in KCRTS), therefore satisfYing the requirements for flow
control. See Section 4 for the infiltration facility design.
2.4 Core Requirement #4: Conveyance System
The new conveyance system consists of Type 1 catch basins and 8-inch and 12-inch storm drain
pipe. The conveyance system will be utilized as an overflow system for the permeable pavement
facility and will connect to an existing catch basin in SW 16 th Street (see Section 5).
2.5 Core Requirement #5: Erosion and Sediment Control
Erosion and sediment control (ESC) measures have been designed for the project in accordance
with Section 1.2.5 of The Manual to prevent the transport of sediment from the site to adjacent
properties and downstream drainage facilities during construction. Temporary measures include
a stabilized construction entrance, silt fencing, tree protection fencing, and inlet protection at
impacted catch basins. Permanent measures to reduce the potential for erosion includes the
proposed permeable pavement facility and the reseeding of disturbed areas (see ESC plan in
APPENDIX D and Section 8.1).
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2.6 Core Requirement #6: Maintenance and Operations
The proposed drainage facilities will follow the operation and maintenance guidelines as
stipulated in Appendix A of The Manual. An operation and maintenance manual consistent with
Appendix A of The Manual has been provided in APPENDIX E of this report.
2.7 Core Requirement #7: Financial Guarantees and Liability
A bond quantities worksheet has been completed and attached as APPENDIX F (see Section 9).
The owner must submit a construction bond to the City of Renton for not less than 100 percent of
the amount calculated in the bond quantity worksheet. The owner must also file a maintenance
bond with the City of Renton before any drainage improvements will be accepted.
2.8 Core Requirement #8: Water Quality
Since the project site is classified as an industrial site and will add more than 5,000 square feet of
pollution generating impervious surface, enhanced basic water quality is required. However,
since the entire site runoff will be infiltrated according to the standards in Section 5.4 of The
Manual, the enhanced basic water quality requirement is reduced to basic water quality treatment
per Exception #2 on Page 1-64 of The Manual. Permeable pavement with an underlying
treatment layer will be used to provide basic water quality to the site's runo ff (see Section 4.5).
2.9 Special Requirement #1: Other Adopted Area-Specific Requirements
The project is exempt from Special Requirement # I because there are no area specific
requirements applicable to the project site.
2.10 Special Requirement #2: Flood Hazard Area Delineation
The parcel in which the project site is located contains a Special Flood Zone which is classified
as a 100-year flood plain. However, no development will occur within the flood plain for this
project. Therefore, the project is exempt from Special Requirement #2.
2.11 Special Requirement #3: Flood Protection Facilities
The project is exempt from Special Requirement #3 because it will not rely on an existing flood
protection facility (such as a levee or revetment) for protection against hazards posed by erosion
or inundation and will not modifY or construct a new flood protection facility.
2.12 Special Requirement #4: Source Control
The project is exempt from Special Requirement #4 because the project does not require a
commercial building or commercial site development.
2.13 Special Requirement #5: Oil Control
The project is exempt from Special Requirement #5 because it does not trigger oil control
requirements since the project site is under the high-use site thresholds.
2.14 Special Requirement #6: Aquifer Protection Area
The project is exempt from Special Requirement #6 because it is not located in Zone I or Zone 2
of the Aquifer Protection Areas identified in Reference II-B of The Manual.
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3. OFFSITE ANALYSIS
Stormwater from the proposed development will be infiltrated onsite through permeable
pavement (porous asphalt) and the project will not change the rate, volume, duration, or location
of discharges to and from the site, Therefore, the project is not required to submit an offsite
analysis report based on exemption #3 on Page 1-21 of the Renton Amendments to the
KCSWDM.
4. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN
The following sections summarize the stormwater flow control and water quality facility analysis
and design.
4.1 Existing Site Hydrology
The existing site is mostly grass with some landscaping and generally slopes southerly away
from the existing building. The underlying soils are undocumented fill and alluvium with an
estimated infiltration rate of 0.5 inches per hour (see section 1.7 and APPENDIX B for more
information on the site soils). Any surface water that does not infiltrate sheet flows towards SW
16 th Street and adjacent properties and enters existing storm systems. See Section 1.2 and
TABLE I for more information on the existing site.
4.2 Developed Site Hydrology
The developed site will consist of approximately 15,000 square feet (0.34 acres) of new plus
replaced impervious surface. The new and replaced impervious surface will be permeable
pavement, with the majority ofthe permeable pavement replacing existing grass. The permeable
pavement will have an underlying rock pocket large enough to detain and infiltrate the 100-year
storm. See FIGURE 3 for the developed drainage basin map and APPENDIX B for onsite soils
information. See Sections 4.4 for more information on the permeable pavement facility design.
4.3 Performance Standards
• The project site lies within the Peak Rate Flow Control Standard area determined from
the City of Renton Flow Control Applications Map and must comply with the
requirements stipulated in Section 1.2.3.1 of The Manual.
• The project is exempt from all flow control BMP requirements because all runoff will be
infiltrated onsite through the permeable pavement facility.
• All conveyance pipes in the overflow system must be designed in accordance with
Section 1.2.4 of The Manual and shall be sized with sufficient capacity to convey and
contain, at minimum, the 25-year peak flow.
• The project site is an industrial site and is subject to the Enhanced Basic Water Quality
Menu as stipulated by The Manual. However, since all runoff from the proposed site will
infiltrate through the permeable pavement facility, the Enhanced Basic Water Quality
requirement is reduced to Basic Water Quality per Exception #2 of Page 1-64 of The
Manual.
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4.4 Flow Control System
As discussed in Section 2, the site is required to provide flow control satisfying the Peak Rate
Flow Control Standard as stipulated in Section 1.2.3.1 of The Manual. The method of flow
control will be full infiltration through the use of permeable pavement that includes a 6" rock
pocket for stormwater storage. The rock storage layer has been sized in KCRTS and in
accordance with The Manual. The tributary area to the infiltration facility is the permeable
pavement parking lot itself. The developed areas used in the modeling for sizing of the facility
are seen in APPENDIX H and explained in Section 4.4.1. A summary of the site's facilities is
shown in TABLE 2.
TABLE 2 Facilities Summary
Facilities Summary
Permeable Pavement Parking Lot
(5) Type 1 Catch Basins
(5) Spill Control Elbows
4.4.1 KCRTS Modeling
The facility was sized in the KCRTS continuous event modeling program. Since all stormwater
is being mitigated onsite through infiltration, matching the Peak Rate Flow Control Standard was
not required. Developed conditions were based on impervious surfuce coverage. See the
modeling results in APPENDIX H for additional design criteria.
The infiltration rate used, 0.5 inches per hour, was stipulated by the geotechnical engineer,
Khaled Shawish, in his memo dated June 21, 2013 (see APPENDIX B for the full geotechnical
memorandum). The facility was sized by iteratively increasing the depth of rock pocket until the
area required for storage was less than the area of the rock pocket. For structural stability of the
permeable pavement section a minimum of6-inches of base course over the entire parking lot
area is required. Since the rock pocket cannot be less than 6-inches thick, this was the beginning
rock pocket depth used in the modeling. Modeling results show that a 6-inch rock pocket is
sufficient to fully detain and infiltrate all stormwater and adds a factor of safety of2 to the
required depth. See APPENDIX H for detailed KCRTS modeling results. The Drainage Plan
submitted under separate cover shows the layout of the permeable pavement facility.
4.5 Water Quality System
Water quality for the site is provided by a combination offacilities within the drainage system: a
permeable pavement parking lot with a soil treatment liner beneath it and a spill control elbow
located in each ofthe five catch basins in the case of an overflow. Since the permeable pavement
facility is a fully infiltrating facility with a soil treatment liner, additional water quality is not
required.
4.5.1 Soil Treatment Liner
Per Section 6.2.4 of The Manual, water quality facilities in which water is in direct contact with
the soil must be lined with either a low permeability liner or a treatment liner when the soil does
not have properties which reduce the risk of groundwater contamination from storm water runoff
that may infiltrate in the facility. Treatment liners must meet the requirements specified in The
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Manual and be placed directly beneath the base rock of the infiltrating facility. A sand layer was
chosen as the treatment liner from the options listed in Section 6.2.4.2 of The Manual and must
be 12 inches in depth. Section 6.2.4 of The Manual explains that treatment liners amend the soil
with materials that treat stormwater before it reaches more freely draining soils, thus satisfying
basic water quality requirements.
5. CONVEYANCE SYSTEM ANALYSIS AND DESIGN
The existing and proposed conveyance systems are discussed in the following sections.
5.1 Existing Conveyance
The only existing conveyance structure on the project site is a Type I catch basin located in a
grass area near the south property line. The catch basin captures sheet flow from the grass area in
which it is located and conveys it southerly to a Type 2 catch basin in the north side ofSW 16th
Street via an 8-inch PVC pipe. The Type 1 catch basin and 8-inch PVC pipe will be removed as a
part 0 f th is project.
5.2 Proposed Conveyance
The proposed conveyance system is comprised of new Type 1 catch basins and 8" and 12" PVC
pipe connecting them to the City's storm system within SW 16 th Street. The conveyance system
is a backup system only as the site has been designed to fully infiltrate all stormwater from the
proposed development. The point of discharge to the City's stormwater system is located just off
the southeast portion of the proposed parking lot. The overflow system will discharge stormwater
via a 12" PVC pipe to an existing catch basin in S W 16 th Street. The 12" line has ample capacity
to convey the modeled runofffrom the site. The 8" pipe between the new Type I catch basins
have been sized to handle anticipated site runoff as well assuming full site runoff for a 100-year
storm event with no attenuation from the porous asphalt (see APPENDIX I for conveyance
calculations).
The overflow for the site is the conveyance system described in the above paragraph. Normally,
the stormwater will infiltrate through the permeable pavement facility, which has been sized to
handle anticipated stormwater amounts. The overflow system will only be used when the porous
asphalt is not allowing storrnwater to infiltrate through it due to clogging of the pores by ice,
sediment, or any other obstruction.
6. SPECIAL REPORTS AND STUDIES
A geotechnical report was completed by Nelson Geotechnical Associates, Inc. (NGA) on June
21, 2013. NGA dug four test pits on June 3, 2013 to depths between 8.5 and 12.0 feet. All four
test pits encountered undocumented fill to depths of3.8 to 4.8 feet. Test Pit locations are shown
on the Schematic Site Plan in APPENDIX B. See TABLE 1 for existing ground cover. See the
Geotechnical memorandum in APPENDIX B for the full geotechnical report.
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7. OTHER PERMITS
Other permits required for this project include:
• Administrative Site Plan Review
• Washington State Environmental Policy Act (SEPA) Review
8. CSWPPP ANALYSIS AND DESIGN
This section summarizes the construction stormwater pollution prevention plan (CSWPPP)
analysis and design. The two components ofthe CSWPPP are the erosion and sediment control
(ESC) and the stormwater pollution prevention and spill (SWPPS) plans. Both the ESC Plan and
SWPPS serve as guides as the contractor is required to design a working CS WPPP for the site.
The analysis and design of these plans are discussed in the following sections.
8.1 ESC Plan Analysis and Design
The ESC design follows the guidelines provided in Appendix D of The Manual and is intended
to satisfy Core Requirement #5 Erosion and Sediment Control.
A stabilized entrance will be maintained throughout construction ofthe site improvements. Silt
fence will be installed downslope of the improvements. Chain link fencing will be used to protect
all trees that are to be preserved onsite. Street cleaning on SW 16th Street will occur daily or as
needed to remove any sediment tracked from the site. Site surface drainage will be maintained to
prevent any ponding and inlet protection will be provided at all existing and proposed catch
basins that may receive runoff during construction. All disturbed areas that will not be paved will
be stabilized by planting and mulching immediately after construction. The proposed ESC
measures are shown on the Temporary Erosion and Sediment Control Plan in APPENDIX D.
An ESC supervisor will be designated for the project and must be a Certified Professional in
Erosion and Sediment Control or a Certified Erosion and Sediment Control Lead, as recognized
by King County. The ESC supervisor will be responsible for the performance, maintenance, and
review of all ESC measures, as well as the compliance with all permit conditions relating to ESC
as described in The Manual.
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Shuttle Express Parking Lot-800 SW 16th Street August 2, 2013
TABLE 3 Proposed ESC Measures and Construction Sequencing
(all ESC Measnres Shall Comply with the KCSWDM Appendix D)
ESC Measure Comment
I IdentifY Project Limits Mark by tencing or other means to contain the
grubbing and grading activities. This includes
installing temporary chain link fencing around
trees that are to remain.
2 Install temporary silt fence Install fence down-slope of the improvements.
3 Construct stabilized Use existing gravel driveway for construction
construction entrance entrance or construct new temporary entrance if
necessary (i.e., sediment tracked onto road).
4 Install inlet protection as Ensure that sediment cannot enter the existing or
required, based on proposed drainage.
construction sequencing
5 Maintain ESC measures Relocate or install new measures if necessary to
meet King County ESC standards (KCSWDM
Appendix D).
6 Street Cleaning Provide for periodic street cleaning to remove
and sediment that may have been tracked out.
Sediment should be removed by shoveling or
sweeping and carefully removed to a suitable
disposal area where it will not be re-eroded.
7 Inspect downstream VerifY that all drainage system components free
drainage system, clean if of sediment. If sediment present then repair or
necessary during implement additional ESC measures.
construction.
8 Surfacing and Sod/Seed Construct pavement, sidewalks, etc. as soon as
Exposed Areas possible. Cleared areas will be sod/seeded as
soon as possible after grading completed.
9 Remove ESC measures After hard surfaces are constructed and cleared
after site stabil ized and areas are stabilized, remove ESC measures and
clean system. clean any sediment/debris in drainage system.
8.2 Stormwater Pollution Prevention and Spill Plan Design
The SWPPS plan is intended to prevent pollutants from coming into contact with stormwater
runoff, surface waters, or groundwater, during construction. Vehicles, construction equipment,
materials, chemical storage, and sediment from clearing and grading all have the potential to
pollute stormwater during construction. The following BMPs are required during the
construction of this project:
• Maintain good housekeeping.
• Designate vehicle, equipment, and chemical storage areas.
Davida Consulting Group, Inc.
TIR_Shuttle Express.doc
Page 15
Technical Information Report
Shuttle Express Parking Lot-800 SW 16th Street August 2, 2013
• Inspect vehicle, equipment, and petroleum product storage and dispensing areas regularly
to detect any leaks or spills.
• Store and contain liquid materials in such a manner that if the tank leaks, the contents
will not discharge into the storm drainage system, surface waters, or groundwater.
• Provide maintenance and cleaning of the storm drainage system regularly by removing
sediment and debris.
• All spills will be cleaned up immediately and disposed correctly. Do not hose down spill
areas to a storm drainage system.
• All toxic materials will be stored under cover when not in use or during a rain event.
• Use storm drain covers or other similarly effective runoff control measures to prevent
sediment and other pollutants from entering catch basins.
All ESC and SWPPS BMPs will be inspected routinely by the ESC supervisor. All ESC
measures will be removed, the site stabilized, and the drainage system cleaned once construction
is completed.
9. BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF
COVENANTS
The bond quantities, facility summaries, and declaration of covenants/agreements are addressed
in the following sections.
• Bond Quantities -The bond quantities for the project are calculated in King County's
Bond Quantity Worksheet attached in APPENDIX F.
• Facility Summaries -The stormwater facilities are summarized in the Stormwater
Facility Summary Sheet attached in APPENDIX G.
• Declaration of Covenants I Agreements - A declaration of covenant for privately
maintained flow control and WQ facilities will be provided under separate cover at a later
time.
10. OPERATIONS AND MAINTENANCE MANUAL
All stormwater facilities should be maintained in accordance with Appendix A ofthe
KCSWDM, which is attached in APPENDIX E. Maintenance ofthe porous asphalt is crucial in
maintaining an infiltrating surface course.
Davido Consulting Group. Inc
TIR_Shuttle Express_doc
Page 16
Technical Information Report
Shuttle Express Parking Lot-800 SW \6'h Street August 2, 2013
APPENDIX A
TlR_Shuttle Express.doc
Figure 1 -Technical Information Report (TIR)
Worksheet
KI:-:G COCNTY, W ASHINGTOl';, SURF ACE WATER DESIGN :vIANUAL
TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
I Part 1 PROJECT OWNER AND i PROJECT ENGINEER
! Project Owner Devin Sherrell
. Phone 425-981-7069
Address 800 SW 16th Street
Renton, WA 98057
Project Engineer Erik Davida, P,E.
Company Davida Consulting Group,Inc.
Phone 206-523-0024
Part 3 TYPE OF PERMIT APPLICATION
I
0 Landuse Services
Subdivison I Short Subd. I UPD
I 0 Building Services
M/F I Commerical I SFR
[J Clearing and Grading
~ Right-ol-Way Use
o Other
PartS PLAN AND REPORT INFORMATION
Technical Information Report
Type 01 Drainage Review W Targeted
(circle): Large Site
Date (include revision 7/01/2013
dates):
Date of Final: TBD
Part 6 ADJUSTMENT APPROVALS
I
Part 2 PROJECT LOCATION AND
DESCRIPTION
Project Name Shuttle Express Parking
Lot ODES Permit # _________ _
Location Township -=2.::3.:cN ___ _
Range __ 4_E ____ _
Section __ 2::..::.4 ___ _
Site Address 800 SW 16th Street
Renton, WA 98057
Part 4 OTHER REVIEWS AND PERMITS
o DFWHPA
o COE404 o DOE Dam Safety o FEMA Floodplain o COE Wetlands o Other
o Shoreline
Management o Stnuctural
RockeryNaultl __
o ESA Section 7
Site Improvement Plan (Engr. Plans)
Type (circle one): @ Modified I
Small Site
Date (include revision 7/01/2013
dates):
Date 01 Final: TBD
Type (circle one): Standard I Complex I Preapplication I Experimental I Blanket
Description: (include conditions in TIR Section 2)
N/A
Date 01 Approval:
2009 Surface Water Design Manual 1/9/2009
I
KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL
TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
Part 7 MONITORING REQUIREMENTS I
Monitoring Required: ves@ Describe:
Start Date:
Completion Date:
Part 8 SITE COMMUNITY AND DRAINAGE s.+.sIN
Community Plan: _____________ _
Special District Overlays: _______________________ _
Drainage8asin: Lower Green River Subwatershed
Stormwater Requirements: Level 1 Flow Control and Basic Water Quality
Part 9 ONSITE AND ADJACENT SENSITIVE ~EAS
DRiver/Stream _________ _ o Steep Slope ________ _
o lake o Erosion Hazard _______ _ o Wetlands __________ _ o landslide Hazard _______ _ o Closed Depression _______ _ o Coal Mine Hazard _______ _ o Floodplain __________ _ o Seismic Hazard _______ _ o Other __________ _ o Habitat Protection ______ _ 0 ________ _
Part 10 SOILS 1
Soil Type Slopes Erosion Potential
Undocumented Fill 0-10% Low
o High Groundwater Table (within 5 feet) o Sole Source Aqu ifer o Other o Seeps/Springs
o Additional Sheets Attached
2009 Surface Water Design Manual
2
119/2009
KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL
TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
Part 11 DRAINAGE DESIGN LIMITATIONS
REFERENCE
o Core 2 -Offsite Analysis
o Sensitive/Critical Areas
IZI SEPA
o Other
LIMITATION / SITE CONSTRAINT
1
0 -----------
I 0 Additional Sheets Attached
Part 12 TIR SUMMARY SHEET (provide one TIR Summary Sheet per Threshold Discharge Areal
Threshold Discharge Area:
(name or description) Project Site
Core Requirements (all 8 apply)
Discharge at Natural Location Number of Natural Discharqe Locations: 1
Offsite Analysis Level: 1 / 2 I 3 dated:
Exempt by full-infiltration
Flow Control Level: it~ 2 I 3 or Exemption Number
(incL facility summary sheet) Small Site MPs
Conveyance System Spill containment located at: NA
Erosion and Sediment Control ESC Site Supervisor: TB D
Contact Phone:
After Hours Phone:
Maintenance and Operation Responsibility: ~ I Public
If Private, Maintenance Loq Required: (i;S)1 No
Financial Guarantees and Provided: ( Yes) No
Liability
Water Quality Type: <-Basic;)/ Sens, Lake I Enhanced Basicm I Bog
(include facility summary sheet) or Exemptionl\Jo.
Landscape ManaQement Plan: t<fe'S) I No
Special Requirements (as applicable)
Area Specific Drainage Type: CDA I SDO I MDP I BP I LMP I Shared Fac. ~
Requirements Name:
Floodplain/Floodway Delineation Type: Major I Minor I Exemption /@~V
100-year Base Flood Elevation (or range):
Datum:
Flood Protection Facilities Describe:
Source Control Describe landuse:
(comm.lindustriallanduse) Describe any structural controls:
2009 Surface Water Design Manual 11912009
3
KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL
TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
Oil Control High-use Site: Yes /~
Treatment BMP:
Maintenance Agreement: Yes /9
with whom?
Other Drainage Structures
Describe:
Part 13 EROSION AND SEDIMENT CONTRO REQUIREMENTS
MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS
DURING CONSTRUCTION AFTER CONSTRUCTION
~ Clearing Limits IZI Stabilize Exposed Surfaces
IZI Cover Measures IZI Remove and Restore Temporary ESC Facilities
IZI Perimeter Protection ~ Clean and Remove All Silt and Debris, Ensure
~ Traffic Area Stabilization Operation of Permanent Facilities
~ Sediment Retention IZI Flag Limits of SAO and open space
~ Surface Water Collection
preservation areas
o Other ~ Dewatering Control
IZI Dust Control
W Flow Control
Part 14 STORMWA TER FACILITY DESCRIPTI )NS (Note: Include FaciHty Summary and Sketch)
Flow Control Type/Description Water Quality Type/Description
o Detention W Biofiltration 1 ' thick sand
treatment liner
W Infiltration Permeable o Wetpool below infiltration
Pavement facility o Regional Facility o Media Filtration
o Shared Facility o Oil Control
o Flow Control o Spill Control
BMPs ~ Flow Control BMPs o Other o Other
2009 Surface Water Design Manual 1/9/2009
4
· ..
KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL
TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
! Part 15 EASEMENTSITRACTS Part 16 STRUCTURAL ANALYSIS
o Drainage Easement o Cast in Place Vault
o Covenant o Retaining Wall o Native Growth Protection Covenant o Rockery > 4' High
o Tract o Structural on Steep Slope o Other o Other
Part 17 SIGNATURE OF PROFESSIONAL ENGINEER
I, or a civil engineer under my supervision, have visited the site. Actual site conditions as observed were
incorporated into this worksheet and the attached Technical Information Report To the best of my
knowledge the information provided here is accurate.
SianediDate
2009 Surface Water Design Manual 1/9/2009
5
•
Technical Information Report
Shuttle Express Parking Lot-800 SW 16 1h Street
Davida Consulting Group, Inc.
TIR_Shuttle Express.doc
APPENDIXB Geotechnical Report
August 2, 2013
•
Main Office
17311 -135 1h Aye NE, A-500
Woodinville, WA 98072
(425) 486-1669 . FAX (425) 481-2510
June 21, 2013
Peer Frank, LLC
c/o Devin Sherrell
800 SW 16'h Street
Renton, Washington 98057
NELSON GEOTECHNICAL
ASSOCIATES, INC.
GEOTECHNICAL ENGINEERS 8: GEOLOGISTS
Engineering-Geology Branch
5526 Industry Lane, #2
East Wenatchee, WA 98802
(509) 665-76% . fAX (509) 665-769'
Geotechnical Engineering Evaluation
Shuttle Express Parking Lot aud Inmtration
800 SW 16'h Street
Renton, Washington
NGA File No. 875613
Dear Mr. Sherrell:
This letter documents our explorations and provides our opinions and recommendations for the proposed
parking lot construction and stormwater infiltration at the existing Shuttle Express office building located
at 800 SW 16th Street in Renton, Washington, as shown on the vicinity map in Figure 1.
INTRODUCTION
The planned improvements will consist of constructing an approximately 16,000 square foot parking lot
within the southern portion of the property along SW 16th Street, along with associated underground
utilities, and a stormwater management system on the property. The site is currently occupied by a multi-
level office building within the central portion of the property with associated parking areas on the north,
east and west sides of the building. The existing and proposed site layouts are shown on the Schematic
Site Plan in Figure 2. For our use in preparing this letter, you have provided us with an aerial image of
the property showing the proposed location of the parking lot area.
Stormwater Infiltration Letter
Shuttle Express Parking Lot and Infiltration
Renton, Washington
SCOPE
June 21, 2013
NGA File No. 875613
Page 2
The purpose of this study is to explore and characterize the subsurface conditions in specific areas of the
site and to provide opinions and recommendations for the proposed parking lot and the potential for
stormwater infiltration. Specifically, our scope of services includes the following:
I. Review existing soils and geologic maps of the area.
2. Explore the site subsurface soil and groundwater conditions with backhoe-excavated test
pits. Backhoe to be subcontracted by NGA.
3. Perform on-site infiltration testing.
4. Perform laboratory analysis on representative soil samples, as needed.
5. Provide recommendations for stormwater infiltration per 2009 King County Surface
Water Design Manual and City of Renton Ammendments.
6. Provide recommendations for pavement sub grade preparation and pavement sections.
7. Provide recommendations for site drainage and erosion control.
8. Provide recommendations for infiltration system installation.
9. Document the results of our explorations, fIndings, conclusions, and recommendations in
a written geotechnical engineering report.
SITE CONDITIONS
Surface Conditions
The site is a relatively level, rectangular shaped lot covering approximately 3.25 acres. The site is
bounded to the north by Interstate 405, to the east and west by commercial properties and to the south by
SW 16th Street. An existing multi-level office building is located within the central portion of the site
with asphalt parking and driveway areas along the north, east and west sides of the building. The
proposed parking lot expansion is to be located within a grass lawn area to the south of the office building
along SW 16th Street. We did not observe surface water on the site during our visit on June 3, 2013.
Subsurface Conditions
Geology: The site is mapped on the Geologic Map of the Renton Quadrangle, King County. Washington,
by D.R. Mullineaux (1965). The site is mapped as Alluvium (Qaw). The alluvium deposits are described
as sand silt and clay deposits. Our explorations generally encountered undocumented fill soils underlain
by silty sand to silt deposits generally consistent with the description of alluvium at depth.
NELSON GEOTECHNICAL ASSOCIATES, INC.
•
Storrnwatcr Infiltration Letter
Shuttle Express Parking Lot and Infiltration
Renton, Washington
June 21, 2013
NGA File No, 875613
Page 3
Explorations: The subsurface conditions within the site were explored on June 3, 2013 by excavating
four test pits with a backhoe, The approximate locations of our explorations are shown on the Schematic
Site Plan in Figure 2. A geologist from Nelson Geotechnical Associates, Inc. (NGA) was present during
the explorations; collected samples of the soils encountered, and maintained logs of the explorations, The
soils were visually classified in general accordance with the Unified Soil Classification System, presented
as Figure 3, The logs of the explorations are presented as Figure 4,
Each of the test pits exposed a surficial layer of topsoil and grass to a depth of 0.2 feet below the existing
ground surface. Underlying the topsoil and grass in al\ of our test pits we encountered approximately 3,8
to 4.8 feet of medium dense to dense, brown gray fine sand with silt, trace gravel and varying amounts of
organics which we interpreted as undocumented fill. Below the fill in all of our test pits, we encountered
looselsoft, iron-oxide stained, brown gray to gray silty sand and sandy silt with varying amounts of gravel
and organics underlain by soft to very soft, blue gray to gray sand, silt with abundant orgaincs that we
interpreted as native alluvium soils mapped for the area. All of our test pits were terminated within the
native alluvium soils at depths in the range of8.5 to 12.0 feet below the existing ground surface.
Hydrologic Conditions
Groundwater seepage was observed at approximately 11.0 and 7.5 feet below the ground surface in Test
Pit I and 3, respectively, In addition, zones of iron oxide staining and saturated soil conditions were
encountered within all of the test pits between approximately 4.0 to 12.0 feet. In our opinion, the
groundwater seepage, iron oxide staining and saturated soil conditions are indicative of the high
groundwater table associated with the nearby river.
SEISMIC HAZARD
The site is shown on the Liquefaction Susceptibility of the Renton Quadrangle, Washington by Stephen P.
Palmer, Henry W. Schasse, Dave K. Norman, et. al. (WSDNR, 1994) to have a high liquefaction
potential. Liquefaction is the temporary loss of the shear strength of a loose soil deposit (usually
submerged clean fine to medium sand) due to a rise in pore water pressures during a seismic event. When
subjected to prolonged cyclic dynamic loads, the pore pressures within a saturated sand deposit increase,
approaching the total overburden pressure. At that time, a "quick" condition develops causing the soil to
temporarily lose its load carrying ability. Depending on the depth to the liquefiable soils and actual loads,
surface settlements can result from liquefaction.
NELSON GEOTECHNICAL ASSOCIA TES, INC,
Stonnwater Infiltration Letter
Shuttle Express Parking Lot and Infiltration
Renton, Washington
June 21, 2013
NGA File No. 875613
Page 4
The majority of the site soils at depth within our explorations consisted of low permeability silts and silty
sand. We did not encounter saturated clean sand layers within our explorations. However, clean sand
layers under groundwater table may exist at depth underlying the site. Based on the soils encountered
within our explorations, we expect the liquefaction potential for the upper site soils to be low. However,
there may be some potential of liquefaction of soil layers at depth below the site, but in our opinion we
would anticipate the impact to the site would be minimal.
ON-SITE INFILTRATION TESTING
We conducted two on-site infiltration tests in the proposed parking lot area. The infiltration tests were
performed within the upper granular fill and underlying native silty sand soils within the parking lot area.
For the infiltration tests, we installed a six-inch diameter vertical tube into the native silty sand soils in
Test Pit 2 at a depth of 5.0 feet below the adjacent ground surface and in the upper granular fill soils in
Test Pit 4 at a depth of approximately 4.0 feet below the adjacent ground surface. Approximately two
inches of pea gravel was placed over the soil in the bottom of the tuhe to limit disturbance of the soil
when water was added to the apparatus. We filled the tube with water and allowed the water to pre-soak
the underlying soils before the actual infiltration testing. After the presoak, we conducted timed
infiltration tests. The infiltration test results are shown below in Table 1. We have not applied a factor of
safety to the in-place infiltration test results shown in the table.
Table 1. Field Results -In-Place Infiltration Test Results
Location Approximate depth Duration of Test Head Loss Measured InfIltration
[ft.1 Imin.1 lin.) Rate lin/hrl
TP-2 5.0 52 6.0 6.92
TP-4 4.0 26 6.0 13.84
CONCLUSIONS AND RECOMMENDATIONS
As stated in the 2009 King County Surface Water Design Manual, a minimum requirement of three feet
of permeable soil below the bottom of the infiltration facility, and at least three feet of separation from the
bottom of the infiltration facility and the maximum wet-season water table needs to exist. In our opinion,
based on the soil and groundwater conditions encountered in our test pits, the site conditions do not meet
these minimum requirements for infiltration.
NELSON GEOTECHNICAL ASSOCIA TES, INC.
,
· .
Storm water Infiltration Letter
Shuttle Express Parking Lot and Infiltration
Renton, Washington
June 21, 2013
NGA File No. 875613
Page 5
It is our opinion that the site subsurface soils are poorly suited for traditional stormwater infiltration
trenches. The subsurface soils generally have a hlgh silt content and indications of shallow groundwater
within these soils were observed in all of our explorations.
It is also our opinion that the use of pervious pavement surfacing to allow runoff from the parking lot to
infiltrate into the granular fill layer found withln the site is feasible. Specific recommendations for
pervious pavement design have been provided in the Pervious Pavement Design subsection of this letter.
Pervious pavement requires on-going maintenance in order to prolong the life span of the pavement.
Specific recommendations for maximizing the life span of the proposed pervious pavement are included
in the Pavement Maintenance subsection of this letter. We should emphasize that on-going maintenance
of the pavement is essential for the long-term success of this approach. All recommendations for
pavement subgrade preparation and maintenance as presented in this letter should be followed for the
parking lot. We are providing a preliminary pavement design; however, this design should be verified by
the civil engineer, based on actual anticipated loads and expected performance and life span of the
pavement, and should also be checked against the recommendations of the pavement supplier.
Pervious Pavement Design
We recommend that the pervious pavement section for the parking lot be a minimum of 6 inches thick
and underlain by a minimum of 12 inches of clean crushed rock. This pavement section is preliminary
and assumes only light traffic would be imposed on the pavement. Permanent design should be the
subject to specific analysis prepared by the civil or traffic engineer and approval by the supplier.
Based on the low permeability soils encountered throughout the site at depth, we recommend that the
pervious pavement section be underlain by a minimum of 12 inches of314-inch clean crushed gravel with
a minimum void ratio of 15 to 20 percent. The gravel should contain no more than 3 percent fines by
weight in order to readily infiltrate into the underlying soils. The gravel layer should help facilitate
infiltration, but will also aid in providing storage for infiltrating water. This layer should only be lightly
compacted. The subgrade below the crushed rock should be stripped of grass and topsoil material to
expose the granular fill soils prior to placing the crushed rock. These soils should generally be
encountered approximately one foot below the existing ground surface. The subgrade below the gravel
layer should be scarified to a depth of six inches and graded leveL The exposed subgrade should not be
heavily compacted or contaminated with silt, as these conditions may reduce the infiltration capability of
NELSON GEOTECHNICAL ASSOCIA TES, INC.
Storm water Infiltration Letter
Shuttle Express Parking Lot and Infiltration
Renton, Washington
June 21,2013
NGAFile No. 875613
Page 6
this material. Also, construction traffic on the exposed subgrade should be avoided. We should be
retained to observe subgrade preparation prior to placing the crushed rock layer.
Based on our observations and on-site infiltration testing along with the varying nature of the underlying
soils throughout the site, we recommend that a design infiltration rate of 0.5 inches per hour be used for
the granular fill material encountered near the ground surface. Additional recommendations and
infonnation regarding pervious pavements are discussed on Pages 97 through III in the Low Impact
Design Technical Gnidance Manual for Pnget Sound, (Pnget Sound Action Team & Washington State
University, May 2005).
The existing underlying fill and crushed rock surface should be proof-rolled with a heavy, rubber-tired
piece of equipment, to identify soft or yielding areas that require repair, however, the clean gravel layer
should only be lightly compacted. We should be retained to observe the proof-rolling, as well as the
placement of the gravel layer, prior to placement of pervious pavement. After installation, pervious
pavements should be thoroughly swept and pressure-washed periodically to minimize siltation potential
as discussed in the following section.
Pavement Maintenance
Typical methods for maintaining paved parking areas should be applied to pervious pavement. These
methods include power sweeping, blowing, vacuuming, and high-pressure washing. Keeping debris from
accumulating on top of and within the pervious pavement is important to maintaining the design
infiltration capacity of the system. Should the pavement become partially clogged with debris,
penneability could possibly be re-established with the use of vacuuming or pressure washing.
Stonnwater from sources outside the pavement should never be directed onto the pervious pavement or
subgrade. Fines and organic material from off-site sources could potentially promote clogging of the
pavement section. Following the recommendations provided in this letter should help reduce the
migration of silt and debris into the pavement section.
USE OF THIS LETTER
This letter was prepared for Peer Frank, LLC and their agents, for their use in planning and budgeting the
above-referenced project only. Our services included an evaluation of the infiltration capability of the site
soils at specific locations, and should not be considered as an in-depth geotechnical study. This letter
may be used for bidding and estimating purposes, but our letter, conclusions, and interpretations should
NELSON GEOTECHNICAL ASSOCIATES, INC.
• •
,,-.'
Stomlwater Infiltration Letter
Shuttle Express Parking Lot and lnfiltration
Renton, Washington
not be construed as a warranty of the subsurface conditions.
June 21, 2013
NGA File No. 875613
Page 7
The suhsurface conditions between
explorations may vary. A contingency for changed conditions should be incorporated into the project
plans.
Within the limitations of scope, schedule, and budget, our services have been performed in accordance
with generally accepted geotechnical engineering practices in effect in this area at the time this letter was
prepared. No other warranty, expressed or implied. is made. Our observations, findings, and opinions are
a means to identify and reduce the inherent risks to the owner.
0-0-0
NELSON GEOTECHNICAL ASSOCIA TES, INC.
Stormwater Infiltration Letter
Shuttle Express Parking Lot and Infiltration
Renton, Washington
June 21. 2013
NGA File No. 875613
Page 8
We appreciate the opportunity to provide service to you on this project. If you have any questions or
require further information, please call.
Sincerely,
NELSON GEOTECHNICAL ASSOCIATES, INC.
LEE S. BELLAH
Lee S. Bellah, LG
Project Geologist
Khaled M. Shawish, PE
Principal
LSB:KMS:kmn
Four Figures Attached
Three Copies Submitted
NELSON GEOTECHNICAL ASSOCIA TES, INC.
., ,
, .
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LEGEND
Property line
Number and approximate
location of test pit
Schematic Site Plan
A "_._~, ••• r-_ • .• "''''' ...... '''''''1 ... ~, •• :uc: 1 inch;: 100 Feet
,_ .. _.
SW 16th Street
.-1
Approximate location
of proposed new
parking lot
N
,
, ,
UNIFIED SOIL CLASSIFICATION SYSTEM
GROUP
MAJOR DIVISIONS SYMBOL GROUP NAME
CLEAN GW WELL-GRADED. FINE TO COARSE GRAVEL
COARSE-GRAVEL
GRAVEL GP POORLY-GRADED GRAVEL
GRAINED MORE THAN 50 %, GRAVEL OF COARSE FRACTION GM SILTY GRAVEL
RETAINED ON
SOILS NO.4 SIEVE WITH FINES
GC CLAYEY GRAVEL
SAND CLEAN SW WELL-GRADED SAND. FINE TO COARSE SAND
SAND
SP POORLY GRADED SAND
MORE THAN 50 %
RETAINED ON MORE THAN 50 %
NO. 200 SIEVE
OF COARSE FRACTION SAND SM SILTY SAND PASSES NO.4 SIEVE
WITH FINES SC CLAYEY SAND
FINE -SILT AND CLAY ML SILT
INORGANIC
GRAINED LIQUID LIMIT CL CLAY
LESS THAN 50 %
SOILS ORGANIC OL ORGANIC SILT. ORGANIC CLAY
SILT AND CLAY MH SILT OF HIGH PLASTICITY. ELASTIC SILT
MORE THAN 50 %
INORGANIC
PASSES LIQUID LIMIT CH CLAY OF HIGH PLASTICITY. FLAT CLAY
NO. 200 SIEVE 50 % OR MORE
ORGANIC OH ORGANIC CLAY. ORGANIC SILT
H IGHL Y ORGANIC SOILS PT PEAT
NOTES:
1) Field classification is based on visual SOIL MOISTURE MODIFIERS:
examination of soil in general ~ accordance with ASTM 0 2488·93. Dry -Absence of moisture, dusty, dry to
the touch
2} Soil dasslfication using laboratory tests :3
Moist -Damp, but no visible water. ~
is based on ASTM D 2488-93. ~
3} Descriptions of soil density or Wet -Visible free water or saturated. ~ usually soil is obtained from consistency are based on below water table ! Interpretation of blowoounl data,
visual appearance of soils, andJor
test data.
~
Project Number ~ELSON GEOTECHNICAL No. Date Revision By CK ::l
875613 Shuttle Express Parking Lot NGA ASSOCIATES, INC. , 6120115 Origlna! LSB KMS ~ ~
Soil Classification Chart GEOTECHNICAL ENGINII!:E:RS 8: GE.OLOGISTS 0
~ • Figure 3 ITJll_135<h~ .. IE. ~·soo ~Cou.ty142!1IJl7_t_ ~ ............... ,WA98071 W"-':;~,",,(5OQ1 ffl4-l7511
,42li148c.-t_,~ .... 4II"2liI~
_~_com
DEPTH (FEET)
TEST PIT ONE
0.0 -0.2
0.2 -4.0
4.0-7.0
7.0 -12.0
TEST PIT TWO
0.0-0.2
0.2-5.0
5.0 -7.0
7.0-8.5
TEST PIT THREE
0.0 -0.2
0.2-5.0
5.0 -7.5
7.5-11.5
TEST PIT FOUR
0.0 -0.2
0.2 -5.0
5.0-11.5
LSB:KMS
usc
SM
ML
SM
ML
LOG OF EXPLORATION
SOIL DESCRIPTION
TOPSOILJGRASS
BROWN-GRAY. FINE TO SAND WITH SILT AND TRACE GRAVEL
(MEDIUM DENSE TO DENSE, MOIST) (FILL)
GRAY IRON-OXIDE STAINED. SILTY FINE TO MEDIUM SAND WITH TRACE GRAVEL AND
ORGANICS (LOOSE. MOIST TO WET)
GRAY SANDY SILT WITH ABUNDANT ORGANICS (LOGS)(SOFT TO STIFF, WET TO SATURATED)
SAMPLES WERE COLLECTED AT 3.0. 4.5. 7.0. AND 11.0 FEET
LIGHT GROUNDWATER SEEPAGE WAS ENCOUNTERED AT 11.0 FEET
SLIGHT TEST PIT CAVING WAS ENCOUNTERED BETWEEN 6.0 AND 11.0 FEET
TEST PIT WAS COMPLETED AT 12.0 FEET ON 613/13
TOPSOILJGRASS
BROWN-GRAY. FINE TO SAND WITH SILT AND TRACE GRAVEL
(MEDIUM DENSE TO DENSE. MOIST) (FILL)
BROWN-GRAY IRON-OXIDE STAINED. SILTY FINE TO MEDIUM SAND WITH TRACE GRAVEL AND
ORGANICS (LOOSE, WET TO SATURATED)
BROWN GRAY SANDY SILT WITH ORGANICS (SOFT. WET TO SATURATED)
SAMPLES WERE COLLECTED AT 3.0. 6.5. AND 7.0 FEET
GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED
TEST PIT CAVING WAS NOT ENCOUNTERED
TEST PIT WAS COMPLETED AT 8.5 FEET ON 613113
TOPSOlllGRASS
BROWN-GRAY. FINE TO SAND WITH SILT AND TRACE GRAVEL
(MEDIUM DENSE TO DENSE. MOIST) (FILL)
SMlML BLUE GRAY IRON-OXIDE STAINED. INTERBEDDED SILTY FINE TO MEDIUM SAND AND SANDY
SILT WITH TRACE ORGANICS (LOOSE/SOFT. WET TO SATURATED)
ML BLUE GRAY SANDY SILT WITH ORGANICS (SOFT TO STIFF. SATURATED)
SAMPLE WAS COLLECTED AT 3.0 FEET
ML
LIGHT GROUNDWATER SEEPAGE WAS ENCOUNTERED AT 7.5 FEET
SLIGHT TEST PIT CAVING WAS ENCOUNTERED BETWEEN 7.5 AND 11.0 FEET
TEST PIT WAS COMPLETED AT 11.5 FEET ON 6/3/13
TOPSOILJGRASS
BROWN-GRAY. FINE TO SAND WITH SILT AND TRACE GRAVEL
(MEDIUM DENSE TO DENSE. MOIST) (FILL)
BLUE GRAY SILT WITH FINE SAND AND ORGANICS (SOFT TO STIFF. WET TO SATURATED)
SAMPLES WERE COLLECTED AT 2.5.5.5.7.5.10.0 AND 11.5 FEET
GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED
TEST PIT CAVING WAS NOT ENCOUNTERED
TEST PIT WAS COMPLETED AT 11.5 FEET ON 613/13
NELSON GEOTECHNICAL ASSOCIA TES, INC.
FILE NO 875613
FIGURE 4
, ,
, ,
Technical Information Report
Shuttle Express Parking Lot-800 SW 16th Street
Davido Consulting Group, Inc.
TIR_Shuttle Express.doc
APPENDIXC Site Improvement Plans
August 2, 2013
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Technical Information Report
Shuttle Express Parking Lot-800 SW 16th Street August 2, 2013
APPENDIXD
Davido Consulting Group, Inc.
TlR_Shuttlc Express,doc
Temporary Erosion and Sediment Control Plan
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Technical Information Report
Shuttle Express Parking Lot-800 SW 16'h Street
Davida Consulting Group, Inc
TIR _Shuttle Express.doc
APPENDIXE Operation and Maintenance
August 2, 2013
'/
O&M Manual August 2, 2013
Shuttle Express Parking Lot
Operation and Maintenance Manual
Person or Organization Responsible for Maintenance of the On-Site Storm System:
Peer Frank, LLC
Devin Sherrell
800 SW 16 th Street
Renton, W A 98057
The Location Where the Operation and Maintenance Manual is to be Kept:
Shuttle Express Business Office
800 S W 16 th Street
Renton, W A 98057
*Note: The manual and maintenance activity log must be made available to the City of
Renton for inspection purposes.
Description of On-Site Storm System
The on-site storm system for the Shuttle Express Parking Lot project consists of a porous
asphalt parking lot with underlying rock pocket and engineered soils layer, Type 1 catch
basins with spill control elbows, and 8-12" storm pipe connecting the proposed catch
basins to the city's storm system in SW 16th Street.
Stormwater runoff from the site will infiltrate through the porous asphalt where there will
be a 6"rock pocket underneath for storage (although a portion of the parking lot will
contain a 12" thick rock pocket for structural stability). The permeable pavement facility
is sized to handle all the stormwater from a 1 DO-year storm with a factor of safety greater
than 2. Only during extreme events (greater than any event in the available data in
KCRTS), a rain on snow event, or ifthe permeable pavement gets clogged and is unable
to allow stormwater to infiltrate, will stormwater be leaving the site through an overflow
system comprised of four catch basins and a conveyance system that connects to an
existing catch basin in the city's system in SW 16 th Street.
Eight-inch storm drain pipe will connect all of the proposed onsite catch basins and a 12"
storm drain will serve the connection to the city's system in SW 16 th Street. All onsite
catch basins will have a downturned 90 degree elbow for oil/water separation/spill
control located inside them.
The permeable pavement facility, catch basins, and spill control elbows serve as source
control of pollution on the project site. In order to control pollutants, proper maintenance
and cleaning of debris, sediments, and oil from stormwater collection and conveyance
systems is required per the operation and maintenance recommendations found in the
2009 King County Surface Water Design Manual (KCSWDM) and the City of Renton
Shuttle Express Parking Lot Dca, Inc.
O&M Manual August 2, 2013
Amendments to the KCS WDM. See the attached sheets for operation and maintenance
requirements pertaining to the project.
Contact Information for Stormwater Facility Installers:
Contractor (Installer of On-Site Storrnwater Facilities)
Bruno DeSimone
Superior Asphalt Maintenance, Inc.
P.O. Box 66956
Burien, W A 98166
Phone -206.246.3237
Bruno@SuperiorAsphaltNW.com
Civil Engineer (Designer of On-Site Stormwater Facilities)
Erik Davido P.E., LEED A.P.
Davido Consulting Group, Inc
15029 Bothell Way NE
Lake Forest Park, WA 98155
Phone -206.523.0024
erik@dcgengr.com
Attachments
• Operation and Maintenance Recommendations for Infiltration Facilities from the
2009 KCSWDM
• Operation and Maintenance Recommendations for Catch Basins and Manholes
from the 2009 KCSWDM
• Operation and Maintenance Recommendations for Conveyance Pipes from the
2009 KCSWDM
• Operation and Maintenance Recommendations for Grounds (Landscaping) from
the 2009 KCSWDM
Shuttle Express Parking Lot DCG, Inc.
••
APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL. CO:-'VEYA:-'CE. AND WQ FACILITIES
NO.2-INFILTRATION FACILITIES
--.----
Maintenance Defect or Problem Conditions When Maintenance Is Needed Results Expected When
Component Maintenance Is Performed
Site Trash and debris Any trash and debris which exceed 1 cubic foot Trash and debris cleared from site.
per 1,000 square feet (this is about equal to the
amount of trash it would take to fill up one
standard size office garbage can). In general,
there should be no visual evidence of dumping.
Noxious weeds Any noxious or nuisance vegetation which may Noxious and nuisance vegetation
constitute a hazard to County personnel or the removed according to applicable
public. regulations. No danger of noxious
vegetation where County personnel
or the public might normally be.
Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of
pollution as oil. gasoline, concrete slurries or paint. according to applicable regulations.
Source control BMPs implemented if
appropriate. No contaminants
present other than a surface oil film.
Grasslgroundcover Grass or groundcover exceeds 18 inches in Grass or groundcover mowed to a
height. height no greater than 6 inches.
Infiltration Pond, Top Rodent holes Any evidence of rodent holes iffacility is acting Rodents removed or destroyed and
or Side Slopes of as a dam or berm, or any evidence of water dam or berm repaired.
Dam, Berm or piping through dam or berm via rodent holes.
Embankment
Tree growth Tree growth threatens integrity of dams, berms or Trees do not hinder facility
slopes, does not allow maintenance access, or performance or maintenance
interferes with maintenance activity. If trees are activities.
not a threat to dam, berm, or embankment
integrity or not interfering with access or
maintenance, they do not need to be removed.
Erosion Eroded damage over 2 inches deep where cause Slopes stabilized using appropriate
of damage is still present or where there is erosion control measures. If erosion
potential for continued erosion. Any erosion is occurring on compacted slope, a
observed on a compacted slope. licensed civil engineer should be
consulted to resolve source of
erosion.
Settlement Any part of a dam, berm or embankment that has Top or side slope restored to design
settled 4 inches lower than the design elevation. dimensions. If settlement is
significant. a licensed civil engineer
should be consulted to determine
the cause of the settlement.
Infiltration Pond, Sediment If two inches or more sediment is present or a Facility infiltrates as designed.
Tank, Vault, Trench, accumulation percolation test indicates facility is working at or
or Small Basin less than 90% of design.
Storage Area
Infiltration Tank Plugged air vent Any blockage of the vent. Tank or vault freely vents.
Structure
Tank bent out of Any part of tank/pipe is bent out of shape more Tank repaired or replaced 10 design.
shape than 10% of its design shape.
Gaps between A gap wider than Yz .. inch at the joint of any tank No water or soil entering tank
sections, damaged sections or any evidence of soil particles entering through joints or walls.
joints or cracks or the tank at a joint or through a wall.
tears in wall
Infiltration Vault Damage to wall, Cracks wider than }'2 .. inch, any evidence of soil Vault is sealed and structurally
Structure frame, bottom, andlor entering the structure through cracks or qualified sound.
top slab inspection personnel determines that the vault is
not structurally sound.
2009 Surface Water Design Manual -Appendix A 1/9/2009
A-3
"
APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES
NO.2-INFILTRATION FACILITIES
Maintenance Defect or Problem Conditions When Maintenance Is Needed Results Expected When
Component Maintenance Is Performed
InlsUOutlet Pipes Sediment Sediment filling 20% or more of the pipe. InleUoutlet pipes clear of sediment.
accumulation
Trash and debris Trash and debris accumulated in inlet/outlet No trash or debris in pipes.
pipes (indudes floatables and non-f1oatables).
Damaged Cracks wider than Vrinch at the joint of the No cracks more than '/4-inch wide at
inlet/outlet pipes or any evidence of soil entering the joint of the inlet/outlet pipe.
at the joints afthe inlet/outlet pipes.
Access Manhole Coverllid not in place Coverllid is missing or only partially in place. Manhole access covered.
Any open manhole requires immediate
maintenance.
Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools.
not working maintenance person with proper tools. Bolts
cannot be seated. Self-locking coverllid does not
work.
Coverllid difficult to One maintenance person cannot remove Coverllid can be removed and
remove coverllid after applying 80 Ibs of lift. reinstalled by one maintenance
person.
Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards.
Allows maintenance person safe
access.
Large access Damaged or difficult Large access doors or plates cannot be Replace or repair access door so it
doors/plate to open opened/removed using normal equipment. can opened as designed.
Gaps, doesn't cover Large access doors not flat and/or access Doors close flat and covers access
completely opening not completely covered. opening completely.
Ufting Rings missing, Lifting rings not capable of lifting weight of door Lifting rings sufficient to lift or
rusted or plate. remove door or plate.
Infiltration Pond, Plugged Filter bag more than 1/2 full. Replace filter bag or redesign
Tank, Vault, Trench, system.
or Small Basin Filter
Bags
Infiltration Pond, Sediment 6" or more of sediment has accumulated. Pre-settling occurs as designed
Tank, Vault, Trench, accumulation
or Small Basin Pre-
settling Ponds and
Vaults
Infiltration Pond, Plugged High water level on upstream side of filter Rock filter replaced evaluate need
Rock Filter remains for extended period of time or little or no for filter and remove if not
water flows through filter during heavy rain necessary.
storms.
Infiltration Pond Rock missing Only one layer of rock exists above native soil in Spillway restored to design
Emergency Overilow area five square feet or larger. or any exposure of standards.
Spillway native soil at the top of out flow path of spillway.
Rip-rap on inside slopes need not be replaced.
Tree growth Tree growth impedes flow or threatens stability of Trees removed.
spillway.
1/9/2009 2009 Surface Water Design Manual -Appendix A
A-4
APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES
NO.5 -CATCH BASINS AND MANHOLES
Maintenance Defect or Problem Condition Wnen Maintenance is Needed Results Expected When
Component Maintenance is Performed
Structure Sediment Sediment exceeds 60% of the depth from the Sump of catch basin contains no
bottom of the catch basin to the invert of the sediment.
lowest pipe into or out of the catch basin or is
within 6 inches of the invert of the lowest pipe
into or out of the catch basin.
Trash and debris Trash or debris of more than "h: cubic foot which No Trash or debris blocking or
is located immediately in front of the catch basin potentially blocking entrance to
opening or is blocking capacity of the catch basin catch basin.
by more than 10%.
Trash or debris in the catch basin that exceeds No trash or debris in the catch basin.
1/3 the depth from the bottom of basin to invert the
lowest pipe into or out of the basin.
Dead an imals or vegetation that could generate No dead animals or vegetation
odors that could cause complaints or dangerous present within catch basin.
gases (e.g., methane).
Deposits of garbage exceeding 1 cubic foot in No condition present which would
volume. attract or support the breeding of
insects or rodents.
Damage to frame Comer of frame extends more Ihan % inch past Fra me is even with curb.
and/or top slab curb face into the street (If applicable).
Top slab has holes larger than 2 square inches or Top slab is free of holes and cracks.
cracks wider than Y.. inch.
Frame not sitting flush on top slab, i.e., Frame is sitting flush on top slab.
separation of more than % inch of the frame from
the top slab,
Cracks in walls or Cracks wider than 1h inch and longer than 3 feel, Catch basin is sealed and
bottom any evidence of soil particles entering catch structurally sound.
basin through cracks, or maintenance person
judges that catch basin is unsound.
Cracks wider than ~ inch and longer than 1 foot No cracks more than 1/4 inch wide at
at the joint of any inlet/outlet pipe or any evidence the joint of inletioutlet pipe.
of soil particles entering catch basin through
cracks.
Settlement/ Catch basin has settled more than 1 inch or has Basin replaced or repaired to design
misalignment rotated more than 2 inches out of alignment. standards.
Damaged pipe joints Cracks wider than 'h-inch at the joint of the No cracks more than Y..-inch wide at
inlet/outlet pipes or any evidence of soil entering the joint of inletioutlet pipes.
the catch basin at the joint of the inlet/outlet
pipes.
Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of
pollution as oil. gasoline, concrete slurries or paint. according to applicable regulations.
Source control BMPs implemented if
appropriate. No contaminants
present other than a surface oil film.
Inlet/Outlet Pipe Sediment Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment.
accumulation
Trash and debris Trash and debris accumulated in inlet/outlet No trash or debris in pipes.
pipes (includes floatables and non-floatables).
Damaged Cracks wider than Y:z-inch at the joint of the No cracks more than Y..-inch wide at
inlet/outlet pipes or any evidence of soil entering the joint of the inlet/outlet pipe.
at the joints of the inlet/outlet pipes.
2009 Surface Water Design Manual -Appendix A 1/9/2009
A-9
APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES
NO.5 -CATCH BASINS AND MANHOLES
Maintenance Defect or Problem Condition When Maintenance Is Needed Results Expected When
Component Maintenance is Performed
Metal Grates Unsafe grate opening Grate with opening wider than 7/g inch. Grate opening meets design
(Catch Basins) standards.
Trash and debris Trash and debris that is blocking more than 20% Grate free of trash and debris.
of grate surface. footnote to guidelines for disposal
Damaged or missing Grate missing or broken member(s) of the grate. Grate is in place and meets design
Any open structure requires urgent standards.
maintenance.
Manhole Cover/Lid Cover/Jid not in place Cover/lid is missing or only partially in place. Coverllid protects opening to
Any open structure requires urgent structure.
maintenance.
Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools.
Not Working maintenance person with proper tools. Bolts
cannot be seated. Self-locking coverllid does not
work.
Coverllid difficult to One maintenance person cannot remove Coverllid can be removed and
Remove cover/lid after applying 80 Ibs. of lift. reinstalled by one maintenance
person.
1/9/2009 2009 Surface Water Design Manual -Appendix A
A-IO
· ,
APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES
NO.6 -CONVEYANCE PIPES AND DITCHES
----
Maintenance Defect or P ... oblem Conditions When Maintenance is Needed Results Expected When
Component Maintenance is Performed
Pipes Sediment & debris Accumulated sediment or debris that exceeds Water flows freely through pipes.
accumulation 2Q% of the diameter of the pipe.
Vegetation/roots Vegetation/roots that reduce free movement of Water flows freely through pipes.
water through pipes.
Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of
pollution as oil, gasoline, concrete slurries or paint according to applicable regulations.
Source control BMPs implemented if
appropriate. No contaminants
present other than a surface oil film.
Damage to protective Protective coating is damaged; rust or corrosion Pipe repaired or replaced.
coating or corrosion is weakening the structural integrity of any part of
pipe.
Damaged Any dent that decreases the cross section area of Pipe repaired or replaced.
pipe by more than 20% or is determined to have
weakened structural integrity of the pipe.
Ditches Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 Trash and debris cleared from
square feet of ditch and slopes. ditches.
Sediment Accumulated sediment that exceeds 20(1/(1 of the Ditch cleaned/flushed of all sediment
accumulation design depth. and debris so that it matches design.
Noxious weeds Any noxious or nuisance vegetation which may Noxious and nuisance vegetation
constitute a hazard to County personnel or the removed according to applicable
public. regulations. No danger of noxious
vegetation where County personnel
or the public might normally be.
Contaminants and ATly evidence of contaminants or pollution such Materials removed and disposed of
pollution as oil, gasoline, concrete slurries or paint. according to applicable regulations.
Source control BMPs implemented if
appropriate. No contaminants
present other than a surface oil film.
Vegetation Vegetation that reduces free movement of water Water flows freely through ditches.
through ditches.
Erosion damage to Any erosion observed on a ditch slope. Slopes are not eroding.
slopes
Rock lining out of One layer or less of rock exists above native soil Replace rocks to design standards.
place or missing (If area 5 square feet or more, any exposed native
Applicable) soil.
2009 Surface Water Design Manual -Appendix A 119/2009
A-II
APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES
NO.11-GROUNDS (LANDSCAPING)
Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When
Component Maintenance is Perfonned
Site Trash or titter Any trash and debris which exceed 1 cubic foot Trash and debris cleared from site.
per 1,000 square feet (this is about equal to the
amount of trash it would take to fill up one
standard size office garbage can). In general,
there should be no visual evidence of dumping.
Noxious weeds Any noxious or nuisance vegetation which may Noxious and nuisance vegetation
constitute a hazard to County personnel or the removed according to applicable
public. regulations. No danger of noxious
vegetation where County personnel
or the public might normally be.
Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of
pollution as oil, gasoline, concrete slunies or paint according to applicable regulations.
Source control BMPs implemented if
appropriate. No contaminants
present other than a surface oil film.
Grasslgroundcover Grass or groundcover exceeds 18 inches in Grass or groundcover mowed to a
height. height no greater than 6 inches.
Trees and Shrubs Hazard Any tree or limb of a tree identified as having a No hazard trees in facility.
potential to fall and cause property damage or
threaten human life. A hazard tree identified by
a qualified arborist must be removed as soon
as possible.
Damaged Limbs or parts of trees or shrubs that are split Of Trees and shrubs with less than 5%
broken which affect more than 25% of the total of total foliage with split or broken
foliage of the tree or shrub. limbs.
Trees or shrubs that have been blown down or No blown down vegetation or
knocked over. knocked over vegetation. Trees or
shrubs free of injury.
Trees or shrubs which are not adequately Tree or shrub in place and
supported or are leaning over, causing exposure adequately supported; dead or
of the roots. diseased trees removed.
1/912009 2009 Surface Water Design Manual Appendix A
A-16
Technical Information Report
Shuttle Express Parking Lot-800 SW 16 th Street
Davida Consulting Group, Inc.
TJR ~Shuttlc Express,doc
APPENDIXF Bond Quantity Worksheet
August 2, 2013
Site Improvement Bond Quantity Worksheet Web dale: 11/28/2007
ti King County
Department of Development lit Environmental Services
900 Oakesdale Avenue Southwest
Renton, Washington 98057-5212
206-296-6600 TTY 206-296-7217
Project Name: Sh uttle Exp ress
Location: 800 SW 16th Street, Renton, WA
Clearing greater than or equal to 5,000 board feet of timber?
______ yes
If yes,
Forest Practice Permit Number:
(RCW 76.09)
Page 1 of 9
Bond Quantity Worksheetxlsx
X no
For alternate formats, call 206-296-6600.
Date: 8/2/2013
Project No.:
Activity No.:
Note: All prices include labor, equipment, materials, overhead and
profit. Prices are from RS Means data adjusted for the Seattle area
or from local sources if not included in the RS Means database.
Unit prices updated: 02112102
Version 04122102
Report Date: 811/2013
Page 2 019
Bond Quantity Worksheetxlsx
Site Improvement Bond Quantity Worksheet
ESC SUBTOTAL:
30% CONTINGENCY & MOBILIZATION:
ESC TOTAL:
COLUMN:
Web date: 1112812007
$ 4,230.82
$ 1,269.25
$ 5,500.07
A
Unit prices updated: 02/12/02
Version: 04122102
Report Date: 8/112013 \.
Page30f9
*KCC 27A authorizes only one bond reduction.
Bond Quantity Worksheet.xlsx
Site Improvement Bond Quantity Worksheet
SUBTOTAL 3,747.20
Web date: 11/28/2007
13,825.48
Unit prices updated: 02112102
Version: 4/22/02
Report Date: 81112013
~
Page 4 019
"'Kec 27 A authorizes only one bond reduction.
Bond Quantity Worksheet.xlsx
Site Improvement Bond Quantity Worksheet
SUBTOTAL 244.58
Web date: 11 f28/2007
12,571.32
Unit prices updated: 02/12/02
Version: 4122102
Report Date: 8/112013
<"
Site Improvement Bond Quantity Worksheet Web date: 11/2812007
Page 5 of 9 SUBTOTAL
Unit prices updated: 02112102
*KCC 27A authorizes only one bond reduction. Version: 4/22/02
Bond Quantity Worksheet.xlsx Report Date: 8/1/2013
Page 6 of 9
·KCC 27A authorizes only one bond reduction.
Bond Quantity Worksheet.xlsx
Site Improvement Bond Quantity Worksheet
SUBTOTAL 522.48
Web date: 11/2812007
10,327.19
Unit prices updated: 02/12/02
Version: 4122102
Report Date: 8/112013
~
Page 7 of 9
"Kec 27A authorizes only one bond reduction.
Bond Quantity Worksheet.x1sx
Site Improvement Bond Quantity Worksheet
SUBTOTAL
Web date: 11/2812007
5225.95
Unit prices updated: 021t2102
Version: 4122102
Report Date: 81t 120t 3
•
Site Improvement Bond Quantity Worksheet
SUBTOTAL
SUBTOTAL (SUM ALL PAGES):
30% CONTINGENCY & MOBILIZATION:
Page8of9
"Kec 27A authorizes only one bond reduction.
Bond Quantity Worksheet.xlsx
GRANDTOT AL:
COLUMN:
4,514.26
1,354.28
5,868.54
B C
Web date: 11/2812007
83,635.00
125,584.94
37,675.48
163,260.42
0 E
Unit prices updated: 02112102
Version: 4122102
Report Date: 811/2013
•
Site Improvement Bond Quantity Worksheet Web date: 11/28/2007
Original bond computations prepared by:
Name: Tim Gabelein, PE Date: 8/2/2013
PE Registration Number: 47652 Tet. #: 206-523-0024
Firm Name: Davida Consulting Group, Inc.
Address: 15029 Bothell Way NE Suite 600, Lake Forest Park, WA 98155 Project No:
ROAD IMPROVEMENTS & DRAINAGE FACILITIES FINANCIAL GUARANTEE REQUIREMENTS
Stabilization/Erosion Sediment Control (ESC) (A) $
Existing Right-of-Way Improvements ~ (B)
Future Public Road Improvements & Drainage Facilitie (C)
Private Improvements (D)
$
$
$
Calculated Quantity Completed
(First $7,500 of bond*" shall be cash.)
PERFORMANCE BOND"
AMOUNT
5,500.1
5,868.5
163,260.4
BOND'AMOUNT
REQUIRED AT RECORDING OR
TEMPORARY OCCUPANCY"""
(E) $
Total Right-of Way andlor Site Restoration Bond"I"" I (A+B) $ 11,368.6
Performance Bond" Amount (A+B+C+D) = TOTAL (T) $ 174,629.0
Minimum bond' amount IS $1000.
T xO.30 $ 52,388.7 OR
Reduced Performance Bond" Total "'"
Maintenance/Defect Bond' Total
NAME OF PERSON PREPARING BOND' REDUCTION:
* NOTE: The word "bond~ as used in this document means any financial guarantee acceptable to King County.
*-NOTE: KeC 27 A authorizes right of way and site restoration bonds to be combined when both are required.
(T-E) $ 174,629.0
Use larger of T)(30% or (T -E)
Date:
PUBLIC ROAD & DRAINAGE
MAINTENANCE/DEFECT BOND"
(B+C) x
0.25= $ 1,467.1
The restoration requirement shall include the total cost for all TESC as a minimum, not a maximum. In addition, correcti'lle work, both on-and off-site needs to be included.
Quantities shall reflect worse case scenarios not just minimum requirements. For example, if a salmonid stream may be damaged, some estimated costs for restoration
needs to be reflected in this amount. The 30% contingency and mobilization costs are computed in this quantity.
**" NOTE: Per KeC 27A, total bond amounts remaining after reduction shall not be less than 30% of the original amount (T) or as revised by major design changes.
SURETY BOND RIDER NOTE: If a bond rider is used, minimum additional performance bond shall be I $ 163,260.4 I(C+D)-E
REQUIRED BON~" AMOUNTS ARE SUBJECT TO REVIEW AND MODIFICATION BY DOES
Page 9 of 9
Check out the DOES Web site at www.kinqcountv.qovlpermits
Bond Quantity Worksheet.xlsx
Unit prices updated: 02/12102
Version: 4/22/02
Report Date: 9/5/2013
•
"
Technical Information Report
Shuttle Express Parking Lot-800 SW 16 th Street August 2, 2013
APPENDIXG
Davida Consulting Group, Inc.
TlR_Shuttle Express.doc
Storm water Facility Summary Sheet
" ..
KING COUt.;TY, WASHINGTON, SURFACE WATER DESIG'l MANUAL
STORMW A TER FACILITY SUMMARY SHEET DOES Permit
Number __ ::-___ -::----:-:-
(provide one Stormwater Facility Summary Sheet per Natural Discharge Location)
Overview:
Project Name
----'S"'h"'u"-t=t"'l-.:oe'---'E=-:x-"p:cr=e-"s-"s'---'P"'a"'r=-:,:k"'i"'nc;:g'---'L"'o"-t"'---_________ Date 8/01/2013
Downstream Drainage Basins
Major Basin Name Green/Duwamish River Watershed
Immediate Basin Name Lower Green River Subwatershed
Flow Control:
Flow Control Facility NamelNumber ___ F=-u=l-=l'---.:I:..:n",f=-l=-' =-l-=t-=r-=a"'t=-:i=-o=-n"'---__ _
Facility
Location 800 SW 16th Street, Renton, WA
Ifnone,
Flow control provided in regional/shared facility (give
location) __ --,---_--,------:-________ ----,_
No flow control required X Exemption number
Full Infiltration
General Facility Information:
TypelNumber of detention facilities: TypelNumber of infiltration facilities:
___ ponds ponds
vaults tanks ---
___ tanks trenches
1 Permeable Pavement Facility
Control Structure Location
Type of Control Structure ______________ Number of Orifices/Restrictions
Size of OrificelRestriction: No, 1
No,2 ______ _
No, 3 ______ _
No, 4 ______ _
Flow Control Performance Standard ______________ _
2009 Surface Water Design Manual
t
119/2009
KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL
Live Storage Volume ________ Depth _______ Volume Factor of Safety
Number of Acres Served _________ _
Number of Lots ________ _
Dam Safety Regulations (Washington State Department of Ecology)
Reservoir Volume above natural grade N / A
Depth of Reservoir above natural grade N / A
Facility Summary Sheet Sketch
All detention, infiltration and water quality facilities must include a detailed sketch.
(II "x17" reduced size plan sheets may be used)
2009 Surface Water Design Manual
2
... "
119/2009
• •
KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL
Water Quality:
Type/Number of water quality facilitieslBMPs:
___ biofiltration swale
large)
(regular/wetl or continuous inflow)
large)
___ combined detentionlwetpond
(wetpond portion basic or large)
___ combined detentionlwetvault
___ filter strip
___ flow dispersion
___ sand filter (basic or large)
___ sand filter, linear (basic or
___ sand filter vault (basic or
sand bed depth ___ (inches)
___ stormwater wetland
___ storm filter
___ wetpond (basic or large)
___ wetvault
_1 __ Is facility Lined?
above
___ farm management plan
___ landscape management plan
_1 __ oil/water separator If so, what marker is used
A permeable pavement parking
(baffle or coalescing plate)
Liner? Sand Liner
area lined with a 12" sand layer as
specified in the KCSWDM Section
6.2.4.2.
catch basin inserts: ---
Manufacturer ________________________________________ __
___ pre-settling pond
___ pre-settling structure:
Manufacturer -------------------
___ high flow bypass structure (e.g., flow-splitter catch basin)
source controls ---
Design Information
Water Quality design flow ________________________ _
Water Quality treated volume (sandfilter) ________________ _
Water Quality storage volume (wetpool) ________________ _
Facility Summary Sheet Sketch
2009 Surface Water Design Manual
3
1/9/2009
KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL
All detention, infiltration and water quality facilities must include a detailed sketch.
(II "x17" reduced size plan sheets may be used)
2009 Surface Water Design Manual
4
· ....
1/9/2009
•
Technical Information Report
Shuttle Express Parking Lot-800 SW 16'h Street
Davido Consulting Group, Inc
TIR_Shuttle Express.doc
APPENDIX H KCRTS Modeling Results
August 2, 2013
KCRTS Modeling -Permeable Pavement Facility
Pl'odl.lc( lon of RUllof f TlI . .: Serle::.
ProJec;t Loe,atlon Sea-Tae
CClJILputlrog Serles bsnAdE"vhr t!;or
':,c~le FQc;(or 1 00
Jata T;n:e Reduced
Hour 1 'l T 11fte SO,er les F lIe
loading Tllle Sene'S Flle r: "!(C_ST,,lDM"-Kr: DAT':"'·STEI60R rllf
o 34 ~' .. T= SCc<hllg Yr 8
----------
Tot,~l Are,~ :.4 ,~cres
Dl:;chal-ge I) 1&1 r:FS at. ~ 01) or. .Jan 9 In Year [;
St-Ol'ltlg lUt8 Ser18S Fda DsnAdE",hr tid
ll:l,e Se~le!: ConLputed
r.CRTc;, COllLlflan,j
E:lte~ t1.", AnalYSIs TUL1LS Modul",
An~lY~lS T~cls Command _ ... --------------------
Coltpute PEAKS and Flou Frequencles
Lo.=odlng Stage·'l'lscli'l.r'3'e Clll:'18 bsnadevhl' tst
Flou Frequency AnalySls
TUle Serles Flle b::;na.de'Jhr tsf
Location Sea-Tae
---I!.nnua~ ~ lO" n:.'HS,,---
F low kate Romk TlIus Cit Peak
(CF5)
[I 083 2/09'01 00
(I 073 1,1)5,02 10:', 00
101 12,-OB,·02 IB 00
085 8,-26_ 04 00
101 10/28/04 16 00
088 1·-18 '·06 10 (10
124 10,,26,06 o 00
161 1/09 '08 b 00
Peaks
-----r lO'" r reqtler,c',r ;mal',r"'ls-------
-l-'eak5 kauk keturn Prot
(CFS) Pe:nc.d
Ct It:.1 1(10 OCt 990
U 124 25 00 %0
o 101 10 00 900
o 101 500 800
o 088 00 667
085 00 500
oe 3 30 231
073 10 091
'" 50 00 no
8 KCRTS ~ Tools _ .,i.;i,;;}~;f:~i,~~_
Compute fEAKS ~nd Flow Frequencies
Plot Flow FREQUENCIES
Compllte Flow D.URATION l:Ind Exceedence
Plot Probl:lbillty EXCEEDENCE CliNeS
.c.OMPARE Flow Durl:ltions
Extract II !:!YDROGRAPH
Plot II Hydro.@RAPH
Compllte :Y:OLUME Discharge
, BETUAN to Previous Menu
ll[--.. _-Compute 11 Row Frequency Curve
~------
,
,
l!l
· ..
KCRTS ~ODELING -?ERMEABLE PAVEMEN~ ?ACILITY
Retentio~/De~ention Facility
Type of Facility:
Facility Length:
Gravel Infiltration
3556.06 ft
Trench
Facili ty Width: 2.00 ft
Facility Area:
Effective Storage Depth:
Stage 0 Elevation:
Storage Volume:
Vertical Permeability:
Permeable Surfaces:
7112.
0.50
100.00
1067.
120.00
Bottom
sq. ft
ft
ft
cu. ft
min/in
Riser Head: 0.50 ft
Riser Diameter: 12.00 inches
Top Notch Weir: None
Outflow Rating Curve: None
Stage Elevation Storage Discharge
(ft) (ft) (cu. ft) (ac-ft) (efs)
0.00 100.00 O. 0.000 0.000
0.03 100.03 64. 0.001 0.000
0.05 100.05 107. 0.002 0.000
0.08 100.08 171. 0.004 0.000
0.10 100.10 213. 0.005 0.000
0.13 100.13 277. 0.006 0.000
0.15 100.15 320. 0.007 0.000
0.18 100.18 384. 0.009 0.000
0.20 100.20 427 . 0.010 0.000
0.23 100.23 491. 0.011 0.000
0.25 100.25 533. 0.012 0.000
0.28 100.28 597. 0.014 0.000
0.30 100.30 640. 0.0;'5 0.000
0.33 100.33 704. 0.016 0.000
0.35 100.35 747. 0.017 0.000
0.38 100.38 811. 0.019 0.000
0.40 100.40 854. 0.020 0.000
0.43 100.43 918. 0.021 0.000
0.45 100.45 960. O. 022 0.000
0.48 100.48 1024. 0.024 0.000
0.50 100.50 1067. 0.024 0.000
0.60 100.60 1067. 0.024 0.308
0.70 100.70 1067. 0.024 0.871
0.80 100.80 1067. 0.024 1.600
0.90 100.90 1067. 0.024 2.390
1. 00 101.00 1067. 0.024 2.670
1.10 101.10 1067. 0.024 2.930
1. 20 101.20 1067. 0.024 3.160
1. 30 101. 30 1067. 0.024 3.380
1. 4 0 101.40 1067. 0.024 3.590
1. 50 101.50 1067. 0.024 3.780
1. 60 101. 60 1067. 0.024 3.970
Percolation
(cfs)
0.00
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
0.08
.. .
1. 70 101.70 1067. 0.024 4.140 0.08
1. 80 101.80 1067. 0.024 4.310 0.08
1. 90 101.90 1067. 0.024 4.470 0.08
2.00 102.00 1067. 0.024 4.630 0.08
2.10 102.10 1067. 0.024 4.780 0.08
2.20 102.20 1067. 0.024 4.930 0.08
2.30 102.30 1067. 0.024 5.070 0.08
2.40 102.40 1067. 0.024 5.210 0.08
2.50 102.50 1067. 0.024 5.350 0.08
Hyd Inflow Outflow Peak Storage
Target Calc Stage Elev (Cu-Ft) (Ac-Ft)
1 0.16 0.00 0.00 0.50 100.50 1067. 0.024
2 0.12 ******* 0.00 0.09 100.09 198. 0.005
3 0.10 ******* 0.00 0.07 100.07 149. 0.003
4 0.10 ******* 0.00 0.05 100.05 113 . 0.003
5 0.09 ******* 0.00 0.03 100.03 72. 0.002
6 0.08 ******* 0.00 0.03 100.03 62. 0.001
7 0.08 ******* 0.00 0.03 100.03 54. 0.001
8 0.07 ******* 0.00 0.02 100.02 45. 0.001
.. " ....
Technical Information Report
Shuttle Express Parking Lot-800 SW 16th Street
Davida Consulting Group. {nc.
T1R_Shuttle Express.doc
APPENDIX I Conveyance Calculations
August 2, 2013
· ...
RATIONAL METHOD
for Conveyance Facility Sizing
(Based on 1998 King County Surface Water Design Manual Section 3.2.1)
Project:
Description:
Design Storm:
Shuttle Express Parking Lot
Rational method for SD pIpe sizing
100 yr
Q-CIA
Where Q = peak flow (etS)
C = estimated composite runoff coefficient
I = peak rainfall intensity (inchesJhour)
A = drainage subbasin area (acres)
Composite Runoff Coefficient
Cc = (C1~A1+C2*A2. __ )lAI
Where: Cc = composite runoff coefficient
C# = runoff coefficient for Area #
A# = area of land cover (acres)
At = total area (acres)
C.
,
Cc =
QnsitefNew
OnsitelNew
0.90
Oescription
Impervious Surface
Pervious Surface
(total C#"A#)1(total area)
Time of Concentration
Seg.'
1
Description of Flow Path Segment
Paved Area (sheet flow) and shallow gutter flow
Totals:
Unity Peak Intensity Factor
if = ar'"Tc"-br
where: Tc = time of concentration (minutes)
ar and br = coefficients from Table 3.2.1.8
Ares (sf)
7,500
0
Totals:
Length (tt)
'40
'40
Te=
ar=
br=
6.30
2.61
0.63
minutes (from table above or 6.3 minimum or 100 max)
(from Table 3.2.1.8)
ir = 0.82
Peak Rainfall Intensity
If= Pr"ir
(from Table 3.2.1.8)
where· Ir = peak rainfall intensity (inchesfhour)
Pr = tolal24-hour preCipitation for design return period (inchesl24 hours)
ir = unit peak rainfall intensity factor
precipitation (inches) Pr=
ir=
3.9
0.82 unit peak intensity factor (from above)
Ir =
Peak Runoff Rate
Q = C~Ir"A
3.19 incheslhour
c=
Ir=
A=
0.90
3.19
0.17
Ce (unilleSS) from above
Ir (inchesfhour) from above
total area (acres) from above
Q= 0.495 cis
Pipe Capacity Calculations (Manning's Equation)
Full Flow (diD = 0.90)
Description
8" for half site
ID (inches)
8
Area (sf)
0.34906585
Storm Drain Pipe Sizin9-Rational Method_Bl.xls
Calculations
Wetted Per.
Iftl
2.094395102
Hyd.
Radius (ttl
0.16666667
Manning's
n
0.011
DCG,/rlc.
"'e.
(acres)
0.17
0_00
0.17
k'
20
Slope
llIIft)
0.0042
Upper
Elev
16.75
Velocity
(Ws)
2.66
lower
Elev
15.5
C
0.90
0.25
Slope
(Illftl
0.005
Pipe
Capacity
(cis)
0.928
A'C
0.15
0.00
0.15
Travel
Time
(minutes)
2.77
2.8
Req'd Flow
(cis)
0.495
8/1f2013
Capacity OK
Page1of1