HomeMy WebLinkAbout16204 114TH AVE SE SHORT PLAT TIR-2016-08-15coterra
321 3rd Avenue South, Suite 406
Seattle, Washington 98104
206.596.7115
TECHNICAL INFORMATION REPORT
Project: Limelite Short Plat
16204 114th Ave SE
Renton, WA 98055
Prepared For: Limelite Development
14508 NE 20th St. #200
Seattle, WA 98007
Reviewed By: Peter Apostol, PE
Date: August 15, 2016
ENGINEERING PLLC
Limelite Short Plat Page 1 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
TABLE OF CONTENTS
Section No. Subject Page No.
SECTION I PROJECT OVERVIEW .....................................................................2
SECTION II CONDITIONS AND REQUIREMENTS SUMMARY...................11
SECTION III OFFSITE ANALYSIS......................................................................13
SECTION IV FLOW CONTROL AND WATER QUALITY
FACILITY ANALYSIS AND DESIGN..........................................27
SECTION V CONVEYANCE SYSTEM ANALYSIS AND DESIGN................30
SECTION VI SPECIAL REPORTS AND STUDIES.............................................30
SECTION VII OTHER PERMITS ...........................................................................30
SECTION VIII EROSION AND SEDIMENT CONTROL.......................................30
SECTION IX BOND QUANTITIES AND
DECLARATION OF COVENANTS...............................................31
SECTION X OPERATIONS AND MAINTENANCE MANUAL.......................31
LIST OF FIGURES
FIGURE 1 VICINITY MAP.................................................................................4
FIGURE 2 TIR WORKSHEET ............................................................................5
FIGURE 3 EXISTING SITE SOILS.....................................................................8
FIGURE 4 EXISTING CONDITIONS.................................................................9
FIGURE 5 DEVELOPED CONDITIONS..........................................................10
FIGURE 6 DOWNSTREAM FLOWPATH.......................................................25
FIGURE 7 DOWNSTREAM LIMIT OF THE OFFSITE ANALYSIS .............28
FIGURE 8 FLOW CONTROL BMP’S..............................................................29
LIST OF APPENDICIES
APPENDIX A CIVIL PLANS
APPENDIX B KCRTS DETENTION TANK CALCULATIONS
APPENDIX C 114th AVE SE BACKWATER ANALYSIS
APPENDIX D BOND QUANTITY CALCULATION
APPENDIX E DECLARATION OF COVENANTS
APPENDIX F OPERATION AND MAINTENANCE MANUAL
APPENDIX G GEOTECHNICAL REPORT
Limelite Short Plat Page 2 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
SECTION I – PROJECT OVERVIEW
General Description:
This project is located at 16204 114th Ave SE on the southeast corner of 114th Ave SE
and SE 162nd Street. See Figure 1 Vicinity Map. The existing 0.687 acre site will be
short platted into a 5-lot subdivision. The proposed lots are intended for the development
of detached single family homes. The existing residence and detached garage are
proposed to be removed prior to the recording of the short plat. Access to proposed Lots
1 and 2 would be from private driveways extended from SE 162nd Street. Proposed Lots
3 and 4 will take access from 114th Ave SE via private driveways. Proposed Lot 5 would
take access via an access easement extended across proposed Lot 4.
Site improvements will include grading, flow control BMP’s, stormwater facilities, utility
connections and landscaping. Frontage improvements will be constructed along 114th
Ave SE and SE 162nd Street and include new sidewalks, curb and gutter and planter
areas. A storm drain extension is required in 114th Ave SE to extend to our site. A
sanitary sewer main extension is required in SE 162nd St.
The proposed project has been designed to meet the requirements of the 2010 City of
Renton Amendment to the 2009 King County Surface Water Design Manual (KCSWD).
A summary of the project data is provided in the TIR worksheet (see Figure 2).
Site Soils
The NRCS map (see Figure 3) of the site shows the presence of Alderwood soils located
within the project area. See Appendix G for the Geotechnical Report.
Predeveloped Conditions:
An existing single story residence with a detached garage is located at the center of the
property. Gravel driveway access is provided from both SE 162nd Street and 114th Ave.
The remainder to the site consists of lawn with trees located along both streets. On-site
grades are less than 1%. Stormwater runoff drains overland to an existing ditch in the
right-of-way which runs along 162nd Street and 114th Ave SE. The existing roadways are
both crowned along the centerline and flow into the aforementioned ditch. Roadway
slopes range from 1% to 6%.
The limits of work are located within one Threshold Discharge Area which is defined by
the City of Renton Amendment to the KCSWD as;“an onsite area draining to a single
natural discharge location, or multiple natural discharge locations that combine within
one-quarter –mile downstream”.Threshold Discharge Area #1 (TDA #1) includes the
on-site project area and the frontage improvements within the right-of-way.
The existing land cover for the site and frontage improvements is shown in Figure 4
which follows this section. The downstream flow path is described in the offsite analysis
in Section III.
Limelite Short Plat Page 3 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
Developed Conditions:
The existing site will be short platted into a 5-lot subdivision with each lot containing a
single-family home. Proposed improvements for each lot will include new driveways,
concrete walkways, drainage improvements, landscaping and site grading. Frontage
improvements of the adjacent right-of-way will include construction of new curb and
gutter, sidewalk, planting strip, driveway and drainage improvements. The anticipated
lot coverage for the developed condition is included as Figure 5 which follows this
section.
Developed Conditions (On Site)
Impervious Cover: Total = 0.37 Ac.
Max. Impervious* 0.37Ac.
Pervious Cover: Total = 0.32 Ac.
Lawn/Landscape: 0.32 Ac.
Project Site Total (On Site): 0.69 Ac.
*see Section IV for details of maximum impervious coverage
The existing site topography will not be dramatically altered in the proposed condition.
Stormwater will be discharged from the site within the same TDA.
Limelite Short Plat Page 4 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
FIGURE 1 – VICINITY MAP
Project Site
16204 114th Ave SE
Limelite Short Plat Page 5 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
FIGURE 2
TECHNICAL INFORMATION REPORT (TIR) WORKSHEET
Part 1 PROJECT OWNER AND
PROJECT ENGINEER
Part 2 PROJECT LOCATION AND
DESCRIPTION
Project Owner : Limelite Development
Address : 14508 NE 20th , WA 98056
Phone : 425-226-1850
Project Engineer: Peter Apostol, PE
Company: Coterra Engineering, PLLC
Address/Phone: 206 596 7115
Project Name : Limelite Short Plat
Location : 16204 114th Ave SE, Renton, WA
98055
Township: 23N
Range: 5E
…………. Section: 29
Part 3 TYPE OF PERMIT
APPLICATION Part 4 OTHER REVIEWS AND PERMITS
Subdivison
Short Subdivision
Grading
Commercial
Other _______________________
_______________________________
DFW HPA Shoreline Management
COE 404 Rockery
DOE Dam Safety Structural Vaults
FEMA Floodplain Other
COE Wetlands
Part 5 SITE COMMUNITY AND DRAINAGE BASIN
Community: Renton
Drainage Basin
Part 6 SITE CHARACTERISTICS
River ________________________________
Stream ___________________________
Critical Stream Reach
Depressions/Swales
Lake
Steep Slopes ______________________
Floodplain ______________________
Wetlands
Seeps/Springs
High Groundwater Table
Groundwater Recharge
Other __________________________
Limelite Short Plat Page 6 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
Part 7 SOILS
Soil Type
Arents, Alderwood
Material
Slopes
6% to 15%
Erosion Potential
Moderate
Erosive Velocities
_________________
_________________
Additional Sheets Attached
Part 8 DEVELOPMENT LIMITATIONS
REFERENCE
______________________________
______________________________
______________________________
______________________________
______________________________
______________________________
Additional Sheets Attached
LIMITATION/SITE CONSTRAINT
_______________________________________
_______________________________________
_______________________________________
_______________________________________
_______________________________________
_______________________________________
Part 9 ESC REQUIREMENTS
MINIMUM ESC REQUIREMENTS
DURING CONSTRUCTION
Sedimentation Facilities
Stabilized Construction Entrance
Perimeter Runoff Control
Clearing and Grading Restrictions
Cover Practices
Construction Sequence
Other
MINIMUM ESC REQUIREMENTS
AFTER CONSTRUCTION
Stabilize Exposed Surface
Remove and Restore Temporary ESC Facilities
Clean and Remove All Silt and Debris
Ensure Operation of Permanent Facilities
Flag Limits of SAO and open space
preservation areas
Other
Limelite Short Plat Page 7 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
Part 10 SURFACE WATER SYSTEM
Grass Lined Channel
Pipe System
Open Channel
Wet Pond
Stormtech Detention
Chamber System
Tank
Vault
Energy Dissipater
Wetland
Stream
Infiltration
Depression
Flow Dispersal
Waiver
Regional
Detention
Method of Analysis
KCRTS
Compensation/Mitigati
on of Eliminated Site
Storage
N/A
Brief Description of System Operation: Piped conveyance to on-site detention tank.
Facility Related Site Limitations
Reference Facility Limitation
____________ ________________ ________________________________________________
____________ ________________ ________________________________________________
Part 11 STRUCTURAL ANALYSIS Part 12 EASEMENTS/TRACTS
Cast in Place Vault
Retaining Wall
Rockery > 4’ High
Structural on Steep Slope
Other
Drainage Easement
Access Easement
Native Growth Protection Easement
Tract
Other
Part 13 SIGNATURE OF PROFESSIONAL ENGINEER
I or a civil engineer under my supervision my supervision have visited the site. Actual site
conditions as observed were incorporated into this worksheet and the attachments. To the best of
my knowledge the information provided here is accurate.
Signed/Date
07/07/2016
Limelite Short Plat Page 8 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
FIGURE 3 – EXISTING SITE SOIL CONDITIONS
AgC, Alderwood gravelly
sandy loam, 6 to 15 percent
slopes
coterra321 3rd Avenue South, Suite 307Seattle, Washington 98104206.596.7115 coterraengineering.comENGINEERING PLLC
coterra
321 3rd Avenue South, Suite 307Seattle, Washington 98104206.596.7115 coterraengineering.com
ENGINEERING PLLC
Limelite Short Plat Page 11 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
SECTION II – CONDITIONS AND REQUIREMENTS SUMMARY
The proposed project is subject to a Full Drainage Review and is therefore subject to all
eight core requirements and all six special requirements. These requirements are listed
below along with a discussion of their applicability to this project.
Core Requirements:
Req. #1 Discharge at Natural Location:
Existing discharge locations will be maintained.
Req. #2 Offsite Analysis:
See Section III below.
Req. #3 Flow Control:
The project triggers flow control requirements as the amount of new plus replaced
impervious surface will be greater than 2,000 SF. Based off the City of Renton
Flow Control Application Map, this project is required to meet the flow control
duration standard for forested conditions. In addition, at least one flow control
BMP is required.
Req. #4 Conveyance System:
The new conveyance system will be designed to meet this requirement.
Req. #5 Erosion and Sediment Control:
Construction ESC systems have been designed to meet this requirement.
Req. #6 Maintenance and Operations:
A Declaration of Covenant is required for this project and is included in Appendix
E. Declaration of Covenant shall be reviewed by City of Renton staff before
recording. The proposed facilities will be owned and maintained by the land
owners.
Req. #7 Financial Guarantees:
A financial guarantee will be necessary for this project. Bonding will be required
for the construction of improvements and will be obtained prior to construction.
Limelite Short Plat Page 12 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
Req. #8 Water Quality:
This project will construct 4,225 SF of new plus replaced PGIS surface and will
not trigger the 5,000 SF threshold.
Special Requirements:
Req. #1 Area Specific Requirements:
No area specific requirements are applicable to this project.
Req. #2: Floodplain/Floodway Delineation
This project is not adjacent to any floodplains or floodways. Therefore no
delineation is necessary.
Req. #3 Flood Protection Facilities:
This project is not adjacent to any applicable areas and will not affect any
applicable facility.
Req. #4 Source Controls:
This project will provide appropriate source controls.
Req. #5 Oil Control:
No oil control requirements are applicable to this project
Req. #6 Aquifer Protection Area
Limelite Short Plat Page 13 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
SECTION III – OFFSITE ANALYSIS
Task 1 – Study Area Definition and Maps
Maps of the project site and surrounding area were obtained from the King County GIS
website. Topographical site information is from the topographical survey for the project.
Storm drainage system maps were compiled from City of Renton GIS maps and as-built
plans. Aerial images were obtained from GoogleMaps.
Task 2 – Resource Review
The City of Renton Public Works Department was contacted regarding the resources
listed in section 2.3.1.1 of the 2010 City of Renton Addendum to KCSWDM. The
following is a summary of the resource review:
Adopted Basin Plans
o King County Basin Name: East Lake Washington (per King County
iMap)
Basin Reconnaissance Summary Reports
o None completed to our knowledge.
Floodplain/Floodway (FEMA) Maps
o The site is not within a floodplain or floodway per FEMA mapping.
Other Offsite Analysis Reports
o Other Offsite Analysis Reports were not available.
Environmentally Sensitive Areas Map
o There are no Environmentally Sensitive areas mapped within the vicinity
of the site.
USDA Soils Survey
o The USDA Web Soil Survey shows the project soils as being Alderwood
gravelly sandy loam. A geotech report will be completed before the
construction permit is applied for.
Wetlands Inventory Maps
o There are no Wetlands mapped within the vicinity of the site.
Limelite Short Plat Page 14 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
Task 3 – Field Inspection
A Level 1 downstream analysis was performed on the morning of May 22, 2014.
Weather conditions during the downstream analysis consisted of overcast skies and the
temperature was 60-65 degrees F. No rainfall occurred in the week prior to the analysis.
On-site landuse and topography was confirmed and the downstream conveyance system
from the project site was identified. Additional information was provided by Steve Lee
who is the stormwater engineer at the City of Renton. He was able to confirm and help
clarify questions about the downstream conveyance described below.
Field Notes
(Refer to the downstream conveyance system (Figure 6) for ditch and structure locations. The ¼
of a mile downstream point at which the project area is less than 15% of the tributary area was is
shown in Figure 7. The downstream analysis ends along SE 164th Street.)
1 2
Stormwater from the project site flows north and west to an existing ditch within the
right-of-way ditch along SE 162nd St and 114th Ave SE. This ditch begins from a high
point to the east of the project site in front of 11427 SE 162nd Street. The ditch is sloped
to the west towards the project property where it intersects the existing driveway to the
west of the property line. Stormwater overflows the ditch and sheet flows across the
driveway where the ditch continues to flow towards SE 162nd Street. The ditch along
the north property line has a bottom width of approximately 2.5 - 3.0 ft with 3:1 side
slopes. The grass ditch appears to be in good condition. Different sections of the ditch
bottom have heavy vegetation and leaves.
Limelite Short Plat Page 15 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
2 The ditch heads south along SE 162nd St when it reaches the 114th Ave SE
intersection. The ditch geometry remains the same. The ditch bottom is covered with
leaves in certain areas.
3 The ditch continues south along 114th Ave SE until it reaches a 12” concrete culvert
that crosses beneath the west driveway of the project site. The culvert is halfway full of
small rocks and debris.
Limelite Short Plat Page 16 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
4 5 The ditch flows to the south property line where it enters another 12” concrete
culvert that crosses beneath the driveway of the adjacent property. This section of the
ditch contains trash and debris. The ditch bottom is 1.5’- 2’ with exposed soils and side
slopes of approximately 4:1. The culvert has a concrete headwall and is partially full of
debris.
6 The next section of the ditch is completely filled with large rocks. The culvert ends
cannot be observed within this section of the ditch.
Limelite Short Plat Page 17 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
7 The downstream end of the culvert can be observed from the next ditch section. The
12” concrete culvert is in good condition and remains free from obstructions.
8 The grass ditch in this section is approximately 4-5 feet wide with a 1.5’-2.0’ ditch
bottom and 1:1 side slopes. The ditch is free of debris and vegetation is maintained.
Limelite Short Plat Page 18 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
9 The upstream end of the 12” concrete culvert is partially filled with debris and
weeds. The downstream end of the culvert has a cracked concrete headwall.
Limelite Short Plat Page 19 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
10 The ditch is at this location is full of overgrown weeds. The ditch varies in bottom
width between 2.0’-3.0’. The ditch depth is approximately 2.5’ with 1:1 side slopes.
11 The upstream end of the 12” concrete culvert is not visible due to overgrown
vegetation. The downstream end has a rock headwall. The culvert is obstructed by
overgrown vegetation.
12 The ditch flows south to SE 164th St where it enters a 12” CMP pipe. The ditch in
this section is approximately 6.67 feet wide with a 3 foot bottom and 1:1 side slopes. The
ditch bottom is eroded in one location with bare soils being visible.
Limelite Short Plat Page 20 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
13 The 12” CMP pipe is obstructed with vegetation.
14 The CMP pipe is connected to the catch basin in the northeast corner of the 114th
Ave SE and SE 164th St intersection. The catch basin is constructed with bricks and has
an exposed soils bottom.
Limelite Short Plat Page 21 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
15 16 The downstream conveyance system crosses 114th Ave SE in a 12” CMP pipe
where it connects to a catch basin to west of the intersection. This structure was locked
and could not be accessed.
Limelite Short Plat Page 22 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
17 18 The pipe system continues to the west where it connects to a catch basin in the
shoulder. This structure was also locked and could not be accessed.
19 20 The pipe system is connected to another catch basin near the end of the sidewalk
along SE 164th Street. Access to this structure was prohibited due to the catch basin
being locked.
Limelite Short Plat Page 23 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
21 The catch basin flows into a ditch via a 15” concrete pipe. The pipe end is partially
full with debris.
22 The ditch runs west alongside SE 164th St. It is difficult to assess the limits of the
ditch due to the overgrown vegetation.
Limelite Short Plat Page 24 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
The extent of the downstream analysis ends approximately 140 feet to the west of the
existing culvert.
Task 4 – Drainage System Description and Problem Description
There are no drainage problems within the downstream system recorded on file with the
City of Renton.
Task 5 – Mitigation of Existing or Potential Problems
The conveyance system along SE 162nd Ave and114th Ave SE will be replaced with a
tightline system. The brick catch basin at the northeast corner of the 144th Ave SE and
and SE 164th Street will be replaced. The conveyance system crossing 114th Ave SE and
heading to the west along SE 164 Street was recently constructed. Potential problems are
not anticipated.
coterra321 3rd Avenue South, Suite 307Seattle, Washington 98104206.596.7115 coterraengineering.comENGINEERING PLLC
coterra321 3rd Avenue South, Suite 307Seattle, Washington 98104206.596.7115 coterraengineering.comENGINEERING PLLC
Limelite Short Plat Page 27 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
SECTION IV – FLOW CONTROL AND WATER QUALITY FACILITY
ANALYSIS AND DESIGN
Flow Control
Flow Control BMPs
Per City of Renton comments, this project qualifies as a small lot BMP site. The required
amount of flow control BMP’s for this project is 2,990 SF, which is 10% of the total lot
area. This project will use a recorded Restricted Footprint to limit the maximum
impervious coverage of each proposed lot. A total of 3,943 SF (0.09 acres) will be used
as a Restricted Footprint credit which also applies as a flow control BMP. This project
meets the flow control BMP requirement.
Restricted Footprint / Reduced Impervious Area Calculations
Lot #
Lot
Area
(SF)
Maximum
Impervious
Area (SF -
75% per R-
8 Zoning)
Reduced
Impervious
Footprint
(SF)
Reduction
in
Impervious
Area (SF)
Impervious
Area
Credit*
(SF)
Flow
Control
Impervious
Area (SF)
1 5039 3779.25 2727.75 1051.50 1051.50 1676.24
2 5032 3774.00 2723.96 1050.04 1050.04 1673.92
3 5940 4455.00 3215.48 1239.52 784.52 2430.97
4 8834 6625.50 4782.08 1843.42 0.00 4782.08
5 5065 3798.75 2741.82 1056.93 1056.93 1684.89
Total Area
(SF)29910 22432.5 16191.09 6241.41 3942.99 12248.10
Total Area
(AC)0.69 0.51 0.37 0.14 0.09 0.28
* Difference between Maximum Zoning and Reduced Impervious Footprint OR 4000 SF and
reduced impervious footprint, whichever is less.
This project will also be installing pervious concrete sidewalk in the right-of-way to
provide additional stormwater mitigation from impervious surfaces.
Refer to Figure 8 for flow control BMP areas.
Detention
This project will provide flow control for new plus replace impervious surfaces using a
detention tank composed of 6.5’ diameter pipes in addition to the flow control BMP’s
discussed above. 236 feet of detention pipe is proposed to provide a storage volume of
Limelite Short Plat Page 28 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
7,554 cubic feet. Underdrains are proposed around the bottom perimeter of the detention
tank to prevent groundwater incursion into the detention volume. The detention system
was sized and the flow control outlet structure was modeled and designed using KCRTS.
Refer to Figure 9 for the contributing areas to the tank and to Appendix IV for the
KCRTS modeling report. The table below outlines the developed targeted areas which
are detained within the detention system. As allowed by the KCSWDM Manual and the
City of Renton, the 0.09 acres of onsite impervious area included in the Restricted
Footprint credit was not included as a targeted area.
Developed Conditions Targeted Areas
Impervious (AC) Pervious (AC)
Onsite 0.37 0.32
Restricted
Footprint Credit
-0.09 +0.09
Total Targeted
Areas In Model
0.28 0.41
Right-Of-Way Targeted Areas
Approximately 0.15 acres of right-of-way area improved as a part of the project bypasses
the proposed detention tank. Per KCSWDM section 1.2.3.E(5), mitigation of this small
bypass area is not required as the developed condition 100-year peak discharge from the
bypass area does not increase by more than 0.1 cfs from the existing site conditions 100-
year peak.
See Appendix B for KCRTS discharge calculations for the offsite bypass area.
Full Infiltration Feasibility Analysis
Per the project geotechnical report, prepared by PanGeo and dated June 24, 2014, the site
is underlain by glacial till soils. Groundwater was encountered at a depth of 1 to 5 feet
below the surface during subsurface explorations. Based on soil and groundwater
conditions, infiltration of stormwater would not be effective on the project site. Per City
of Renton comments, a note has been added to the plans to install perforated pipes on all
roof downspout connections.
Water Quality
This project will not be required to implement water quality treatment facilities as it will
not add over 5,000 SF of pollution-generating impervious surfaces for right-of-way or
private improvements.
coterra
321 3rd Avenue South, Suite 307Seattle, Washington 98104206.596.7115 coterraengineering.com
ENGINEERING PLLC
coterra
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ENGINEERING PLLC
Limelite Short Plat Page 31 Project No. 14011
16204 114th Ave SE Coterra Engineering PLLC
SECTION V – CONVEYANCE SYSTEM DESIGN AND ANALYSIS
The conveyance system along 114th Ave SE within the right-of-way is designed to
convey the peak flow for the tributary area. The 12” pipes are designed to have a 0.50%
minimum slope with a full flow capacity of 2.729 CFS. The 25- and 100-year storm
events have peak flows of 1.763 CFS and 2.190 CFS. Refer to Appendix C for the
backwater analysis, tributary areas, and rational method calculations.
SECTION VI – SPECIAL REPORTS AND STUDIES
A geotechnical analysis of the site was performed and is included in Appendix G.
SECTION VII – OTHER PERMITS
No other permits are required.
SECTION VIII – EROSION AND SEDIMENT CONTROL
ESC Measures are being addressed as follows:
Clearing Limits: Clearing limits are being delineated by perimeter silt fencing and
chain link fencing.
Cover Measures: Temporary cover shall be installed if an area is to remain
unworked for more than seven days during the dry season (May 1 to September
30) or for more than two consecutive working days during the wet season
(October 1 to April 30). Any area to remain unworked for more than 30 days shall
be seeded or sodded, unless the City of Renton determines that winter weather
makes vegetation establishment infeasible.
Perimeter Protection: Perimeter protection will be implemented by silt fencing
around the site perimeter where drainage paths require.
Traffic Area Stabilization: A stabilized construction entrance will be built for
construction traffic.
Sediment Retention: Catch basin protection has been provided and is shown on
the projects TESC plans.
Surface Water Control: Surface water will be collected and conveyed via swales
with check dams as necessary.
Dust Control: Dust control, if required, will be provided through the limited use
of water trucks.
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16204 114th Ave SE Coterra Engineering PLLC
SECTION IX – BOND QUANTITIES AND DECLARATION OF COVENANTS
A bond quantity worksheet for the proposed improvements is provided in Appendix D.
A Declaration of Covenant is required for this project and is included in Appendix E.
Declaration of Covenant shall be reviewed by City of Renton staff before recording. The
proposed facilities will be owned and maintained by the land owners.
SECTION X – OPERATIONS AND MAINTENANCE MANUAL
An operation and maintenance manual which outlines required regular maintenance
necessary for the proposed stormwater facilities is provided in Appendix F. The
maintenance of the stormwater facilities will be performed by the owners of the lots per
maintenance agreement.
Appendix A
Civil Plans
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ENGINEERING PLLC
Know what's
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321 3rd Ave South, Suite 307Seattle, Washington 98104ph 206.596.7115coterraengineering.com
ENGINEERING PLLC
Know what's
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6*#8'5'4'06109#.+/'.+6'5*1462.#6coterra321 3rd Ave South, Suite 307Seattle, Washington 98104ph 206.596.7115coterraengineering.comENGINEERING PLLC
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ENGINEERING PLLC
Know what's
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6*#8'5'4'06109#.+/'.+6'5*1462.#6coterra321 3rd Ave South, Suite 307Seattle, Washington 98104ph 206.596.7115coterraengineering.comENGINEERING PLLCKnow what'sR
6*#8'5'4'06109#.+/'.+6'5*1462.#6coterra321 3rd Ave South, Suite 307Seattle, Washington 98104ph 206.596.7115coterraengineering.comENGINEERING PLLCKnow what'sR
6*#8'5'4'06109#.+/'.+6'5*1462.#6coterra321 3rd Ave South, Suite 307Seattle, Washington 98104ph 206.596.7115coterraengineering.comENGINEERING PLLC
6*#8'5'4'06109#
.+/'.+6'5*1462.#6
coterra
321 3rd Ave South, Suite 307Seattle, Washington 98104ph 206.596.7115coterraengineering.com
ENGINEERING PLLC
6*#8'5'4'06109#.+/'.+6'5*1462.#6coterra321 3rd Ave South, Suite 307Seattle, Washington 98104ph 206.596.7115coterraengineering.comENGINEERING PLLC
6*#8'5'4'06109#.+/'.+6'5*1462.#6coterra321 3rd Ave South, Suite 307Seattle, Washington 98104ph 206.596.7115coterraengineering.comENGINEERING PLLC
6*#8'5'4'06109#.+/'.+6'5*1462.#6coterra321 3rd Ave South, Suite 307Seattle, Washington 98104ph 206.596.7115coterraengineering.comENGINEERING PLLC
6*#8'5'4'06109#.+/'.+6'5*1462.#6coterra321 3rd Ave South, Suite 307Seattle, Washington 98104ph 206.596.7115coterraengineering.comENGINEERING PLLC
Appendix B
KCRTS Detention Tank Calculations
Retention/Detention Facility
Type of Facility: Detention Tank
Tank Diameter: 6.50 ft
Tank Length: 236.00 ft
Effective Storage Depth: 6.00 ft
Stage 0 Elevation: 0.00 ft
Storage Volume: 7554. cu. ft
Riser Head: 6.00 ft
Riser Diameter: 12.00 inches
Number of orifices: 2
Full Head Pipe
Orifice # Height Diameter Discharge Diameter
(ft) (in) (CFS) (in)
1 0.00 0.39 0.010
2 4.50 0.97 0.031 4.0
Top Notch Weir: None
Outflow Rating Curve: None
Stage Elevation Storage Discharge Percolation
(ft) (ft) (cu. ft) (ac-ft) (cfs) (cfs)
0.00 0.00 0. 0.000 0.000 0.00
0.01 0.01 8. 0.000 0.000 0.00
0.02 0.02 17. 0.000 0.001 0.00
0.03 0.03 25. 0.001 0.001 0.00
0.13 0.13 112. 0.003 0.002 0.00
0.23 0.23 206. 0.005 0.002 0.00
0.33 0.33 306. 0.007 0.002 0.00
0.43 0.43 411. 0.009 0.003 0.00
0.53 0.53 521. 0.012 0.003 0.00
0.63 0.63 635. 0.015 0.003 0.00
0.73 0.73 753. 0.017 0.004 0.00
0.83 0.83 875. 0.020 0.004 0.00
0.93 0.93 1000. 0.023 0.004 0.00
1.03 1.03 1129. 0.026 0.004 0.00
1.13 1.13 1261. 0.029 0.004 0.00
1.23 1.23 1395. 0.032 0.005 0.00
1.33 1.33 1532. 0.035 0.005 0.00
1.43 1.43 1671. 0.038 0.005 0.00
1.53 1.53 1812. 0.042 0.005 0.00
1.63 1.63 1955. 0.045 0.005 0.00
1.73 1.73 2100. 0.048 0.005 0.00
1.83 1.83 2246. 0.052 0.006 0.00
1.93 1.93 2394. 0.055 0.006 0.00
2.03 2.03 2543. 0.058 0.006 0.00
2.13 2.13 2693. 0.062 0.006 0.00
2.23 2.23 2844. 0.065 0.006 0.00
2.33 2.33 2996. 0.069 0.006 0.00
2.43 2.43 3149. 0.072 0.006 0.00
2.53 2.53 3301. 0.076 0.007 0.00
2.63 2.63 3455. 0.079 0.007 0.00
2.73 2.73 3608. 0.083 0.007 0.00
2.83 2.83 3761. 0.086 0.007 0.00
2.93 2.93 3915. 0.090 0.007 0.00
3.03 3.03 4068. 0.093 0.007 0.00
3.13 3.13 4220. 0.097 0.007 0.00
3.23 3.23 4372. 0.100 0.007 0.00
3.33 3.33 4524. 0.104 0.008 0.00
3.43 3.43 4674. 0.107 0.008 0.00
3.53 3.53 4824. 0.111 0.008 0.00
3.63 3.63 4972. 0.114 0.008 0.00
3.73 3.73 5119. 0.118 0.008 0.00
3.83 3.83 5264. 0.121 0.008 0.00
3.93 3.93 5408. 0.124 0.008 0.00
4.03 4.03 5550. 0.127 0.008 0.00
4.13 4.13 5690. 0.131 0.008 0.00
4.23 4.23 5828. 0.134 0.008 0.00
4.33 4.33 5963. 0.137 0.009 0.00
4.43 4.43 6096. 0.140 0.009 0.00
4.50 4.50 6187. 0.142 0.009 0.00
4.51 4.51 6200. 0.142 0.009 0.00
4.52 4.52 6213. 0.143 0.010 0.00
4.53 4.53 6226. 0.143 0.010 0.00
4.54 4.54 6239. 0.143 0.012 0.00
4.55 4.55 6251. 0.144 0.014 0.00
4.56 4.56 6264. 0.144 0.015 0.00
4.57 4.57 6277. 0.144 0.016 0.00
4.58 4.58 6290. 0.144 0.016 0.00
4.68 4.68 6415. 0.147 0.020 0.00
4.78 4.78 6536. 0.150 0.023 0.00
4.88 4.88 6654. 0.153 0.025 0.00
4.98 4.98 6768. 0.155 0.027 0.00
5.08 5.08 6877. 0.158 0.029 0.00
5.18 5.18 6982. 0.160 0.031 0.00
5.28 5.28 7081. 0.163 0.032 0.00
5.38 5.38 7174. 0.165 0.034 0.00
5.48 5.48 7261. 0.167 0.035 0.00
5.58 5.58 7340. 0.169 0.036 0.00
5.68 5.68 7411. 0.170 0.038 0.00
5.78 5.78 7472. 0.172 0.039 0.00
5.88 5.88 7521. 0.173 0.040 0.00
5.98 5.98 7552. 0.173 0.041 0.00
6.00 6.00 7554. 0.173 0.041 0.00
6.10 6.10 7554. 0.173 0.351 0.00
6.20 6.20 7554. 0.173 0.915 0.00
6.30 6.30 7554. 0.173 1.650 0.00
6.40 6.40 7554. 0.173 2.440 0.00
6.50 6.50 7554. 0.173 2.720 0.00
6.60 6.60 7554. 0.173 2.980 0.00
6.70 6.70 7554. 0.173 3.210 0.00
6.80 6.80 7554. 0.173 3.430 0.00
6.90 6.90 7554. 0.173 3.640 0.00
7.00 7.00 7554. 0.173 3.830 0.00
7.10 7.10 7554. 0.173 4.020 0.00
7.20 7.20 7554. 0.173 4.200 0.00
7.30 7.30 7554. 0.173 4.370 0.00
7.40 7.40 7554. 0.173 4.530 0.00
7.50 7.50 7554. 0.173 4.690 0.00
7.60 7.60 7554. 0.173 4.840 0.00
7.70 7.70 7554. 0.173 4.990 0.00
7.80 7.80 7554. 0.173 5.130 0.00
Hyd Inflow Outflow Peak Storage
Target Calc Stage Elev (Cu-Ft) (Ac-Ft)
1 0.22 ******* 0.07 6.01 6.01 7554. 0.173
2 0.10 0.04 0.04 5.98 5.98 7551. 0.173
3 0.13 ******* 0.04 5.59 5.59 7346. 0.169
4 0.11 ******* 0.02 4.72 4.72 6458. 0.148
5 0.11 ******* 0.01 4.06 4.06 5589. 0.128
6 0.10 ******* 0.01 3.58 3.58 4900. 0.112
7 0.08 ******* 0.01 3.39 3.39 4608. 0.106
8 0.08 ******* 0.00 1.71 1.71 2075. 0.048
----------------------------------
Route Time Series through Facility
Inflow Time Series File:rent-onsite-dev.tsf
Outflow Time Series File:REN-TANK4-OUT
Inflow/Outflow Analysis
Peak Inflow Discharge: 0.219 CFS at 6:00 on Jan 9 in Year 8
Peak Outflow Discharge: 0.067 CFS at 10:00 on Jan 9 in Year 8
Peak Reservoir Stage: 6.01 Ft
Peak Reservoir Elev: 6.01 Ft
Peak Reservoir Storage: 7554. Cu-Ft
: 0.173 Ac-Ft
Flow Duration from Time Series File:ren-tank4-out.tsf
Cutoff Count Frequency CDF Exceedence_Probability
CFS % % %
0.001 32690 53.311 53.311 46.689 0.467E+00
0.002 4200 6.849 60.160 39.840 0.398E+00
0.003 7012 11.435 71.595 28.405 0.284E+00
0.004 4602 7.505 79.100 20.900 0.209E+00
0.005 7631 12.445 91.544 8.456 0.846E-01
0.006 2229 3.635 95.179 4.821 0.482E-01
0.007 1646 2.684 97.864 2.136 0.214E-01
0.008 870 1.419 99.282 0.718 0.718E-02
0.010 221 0.360 99.643 0.357 0.357E-02
0.011 38 0.062 99.705 0.295 0.295E-02
0.012 14 0.023 99.728 0.272 0.272E-02
0.013 9 0.015 99.742 0.258 0.258E-02
0.014 6 0.010 99.752 0.248 0.248E-02
0.015 15 0.024 99.777 0.223 0.223E-02
0.016 17 0.028 99.804 0.196 0.196E-02
0.017 18 0.029 99.834 0.166 0.166E-02
0.019 10 0.016 99.850 0.150 0.150E-02
0.020 4 0.007 99.856 0.144 0.144E-02
0.021 6 0.010 99.866 0.134 0.134E-02
0.022 5 0.008 99.874 0.126 0.126E-02
0.023 4 0.007 99.881 0.119 0.119E-02
0.024 7 0.011 99.892 0.108 0.108E-02
0.025 2 0.003 99.896 0.104 0.104E-02
0.026 5 0.008 99.904 0.096 0.962E-03
0.028 4 0.007 99.910 0.090 0.897E-03
0.029 7 0.011 99.922 0.078 0.783E-03
0.030 5 0.008 99.930 0.070 0.701E-03
0.031 6 0.010 99.940 0.060 0.603E-03
0.032 11 0.018 99.958 0.042 0.424E-03
0.033 2 0.003 99.961 0.039 0.391E-03
0.034 5 0.008 99.969 0.031 0.310E-03
0.035 5 0.008 99.977 0.023 0.228E-03
0.037 5 0.008 99.985 0.015 0.147E-03
0.038 1 0.002 99.987 0.013 0.130E-03
0.039 3 0.005 99.992 0.008 0.815E-04
0.040 1 0.002 99.993 0.007 0.652E-04
Duration Comparison Anaylsis
Base File: ren-hist4.tsf
New File: ren-tank4-out.tsf
Cutoff Units: Discharge in CFS
-----Fraction of Time----- ---------Check of Tolerance-------
Cutoff Base New %Change Probability Base New %Change
0.009 | 0.98E-02 0.36E-02 -63.3 | 0.98E-02 0.009 0.008 -15.7
0.012 | 0.64E-02 0.27E-02 -58.4 | 0.64E-02 0.012 0.009 -25.6
0.015 | 0.48E-02 0.23E-02 -52.2 | 0.48E-02 0.015 0.009 -38.6
0.017 | 0.37E-02 0.17E-02 -53.7 | 0.37E-02 0.017 0.009 -47.6
0.020 | 0.29E-02 0.14E-02 -49.7 | 0.29E-02 0.020 0.011 -44.3
0.023 | 0.22E-02 0.12E-02 -44.1 | 0.22E-02 0.023 0.015 -31.9
0.025 | 0.15E-02 0.10E-02 -30.4 | 0.15E-02 0.025 0.019 -25.0
0.028 | 0.10E-02 0.86E-03 -17.2 | 0.10E-02 0.028 0.025 -9.1
0.030 | 0.60E-03 0.65E-03 8.1 | 0.60E-03 0.030 0.031 1.9
0.033 | 0.34E-03 0.39E-03 14.3 | 0.34E-03 0.033 0.034 3.5
0.036 | 0.23E-03 0.21E-03 -7.1 | 0.23E-03 0.036 0.035 -0.5
0.038 | 0.16E-03 0.98E-04 -40.0 | 0.16E-03 0.038 0.036 -5.6
0.041 | 0.98E-04 0.33E-04 -66.7 | 0.98E-04 0.041 0.039 -5.2
0.044 | 0.16E-04 0.00E+00 -100.0 | 0.16E-04 0.044 0.041 -5.9
Maximum positive excursion = 0.002 cfs ( 4.8%)
occurring at 0.032 cfs on the Base Data:ren-hist4.tsf
and at 0.034 cfs on the New Data:ren-tank4-out.tsf
Maximum negative excursion = 0.009 cfs (-48.4%)
occurring at 0.018 cfs on the Base Data:ren-hist4.tsf
and at 0.009 cfs on the New Data:ren-tank4-out.tsf
Appendix C
114th AVE SE Backwater Analysis
coterra
321 3rd Avenue South,Suite 307Seattle,Washington 98104206.596.7115 coterraengineering.com
ENGINEERING PLLC
BACKWATER ANALYSIS
Project Name:Renton Shortplat Designed By: Henry Stefan Checked By: Peter Apostol
Job Number: 14011 Storm Event:25-YEAR Rational Method
Conveyance System Information Outlet Control Inlet Control Headwater Summation Overtopping Check
Pipe Segment Surface Total Length Pipe "n" Down- Down- Up- Up- Pipe Barrel Barrel Critical Critical TW TW Barrel Friction Entrance Entrance Entrance Exit Outlet Inlet Inlet Control Approach Bend Bend Q1 Q3 V1 Junction Head HW (HW - Rim) Over-
CB/MH # CB/MH # Flow Flow L Size value Stream Stream Stream Stream Slope Velocity Velocity Depth Depth Elev. Check Hyd. Loss HGL Ke Head Head Control Control Control HW Veloctiy Kb Head Head Loss Elev. Clearance topping
Down Up Q Qtot D Invert Rim Invert Rim Head Ratio Rad. Elev. Loss Loss Elev.HW/D Elev. Elev. Head Loss Loss Total Check
CFS CFS FT IN FT FT FT FT % FPS FT FT FT FT FT FT FT FT FT FT FT FT FT FT FT CFS CFS FPS FT FT FT FT
CB #00 CB #01 0.59 3.65 66.0 12 0.012 467.06 472.14 467.39 472.59 0.50% 4.65 0.34 0.66 0.66 468.06 468.06 0.25 0.59 468.65 0.50 0.17 0.34 469.15 1.00 468.39 469.15 0.24 1.33 0.45 3.06 0.36 4.65 0.03 0.48 469.40 -3.19 Okay
CB #01 CB #02 0.28 3.06 62.0 12 0.012 467.39 472.59 467.70 472.70 0.50% 3.90 0.24 0.60 0.60 469.40 469.40 0.25 0.39 469.78 0.50 0.12 0.24 470.14 0.93 468.63 470.14 0.19 0.02 0.00 2.78 3.90 0.00 469.95 -2.75 Okay
CB #02 CB #03 0.82 2.78 100.0 12 0.012 467.70 472.70 468.20 473.20 0.50% 3.54 0.19 0.58 0.58 469.95 469.95 0.25 0.52 470.47 0.50 0.10 0.19 470.76 0.85 469.05 470.76 0.10 0.02 0.00 1.97 3.54 0.00 470.66 -2.54 Okay
CB #03 CB #04 0.77 1.97 130.0 12 0.012 468.20 473.20 468.85 473.85 0.50% 2.50 0.10 0.06 0.47 470.66 470.66 0.25 0.34 471.00 0.50 0.05 0.10 471.15 0.68 469.53 471.15 0.04 0.02 0.00 1.20 2.50 0.00 471.11 -2.74 Okay
CB #04 CB #05 1.03 1.20 155.0 12 0.012 468.85 473.85 469.63 476.60 0.50% 1.53 0.04 0.06 0.36 471.11 471.11 0.25 0.15 471.26 0.50 0.02 0.04 471.31 0.55 470.18 471.31 0.00 0.62 0.02 0.17 0.63 1.53 0.04 0.06 471.37 -5.23 Okay
CB #05 CB #06 0.00 0.17 15.0 12 0.012 469.63 476.60 469.93 479.15 2.00% 0.22 0.00 0.06 0.15 471.37 471.37 0.25 0.00 471.37 0.50 0.00 0.00 471.38 0.10 470.03 471.38 0.00 0.62 0.00 0.17 0.22 0.00 471.38 -7.77 Okay
CB #06 CB #07 0.00 0.17 144.0 12 0.012 473.73 479.15 475.17 479.81 1.00% 0.22 0.00 0.06 0.15 471.38 474.31 0.25 0.00 476.17 0.50 0.00 0.00 476.17 0.10 475.27 476.17 0.00 0.62 0.00 0.17 0.22 0.00 476.17 -3.64 Okay
CB #07 CB #08 0.14 0.17 45.0 12 0.012 477.30 479.81 477.75 480.61 1.00% 0.22 0.00 0.06 0.13 476.17 477.87 0.25 0.00 478.75 0.50 0.00 0.00 478.75 0.10 477.85 478.75 0.00 0.21 0.00 0.02 0.22 0.00 478.75 -1.86 Okay
CB #08 CB #09 0.02 0.02 174.0 12 0.012 477.75 480.61 480.40 482.81 1.52% 0.03 0.00 0.06 0.06 478.75 478.75 0.25 0.00 481.40 0.50 0.00 0.00 481.40 0.10 480.50 481.40 0.21 0.00 0.00 0.03 0.00 481.40 -1.41 Okay
481.40
coterra
ENGINEERING PLLC
collaborative civil engineering + site development + infrastructure design
14011 Backwater Analysis - Rational Method.xls 8/16/2016
CONVEYANCE INPUTS AND LAYOUT DATA
Project Name:Limelite Short Plat Event Parameters: Runoff Coefficients:
Job Number:14011 Event PR aR bR Tc iR IR C impervious 0.90
Designed By:MEB in unitless unitless min unitless in/hr C pervious 0.25
25-yr, 24-hr 3.4 2.66 0.65 10.4 0.58 1.97
100-yr, 24-hr 3.9 2.61 0.63 10.4 0.60 2.33
CB CB Impervious Pervious Total Total C IR, 25-yr Q25-yr Q25-yr IR,100-yr Q100-yr Q100-yr
Downstream Upstream Area Area Area Area Surface Total Surface Total
sf sf sf ac unitless in/hr cfs cfs in/hr cfs cfs
CB #00 CB #01 11,707 9,966 21,673 0.50 0.60 1.97 0.59 3.65 2.33 0.70 7.36
CB #01 CB #02 5,449 5,213 10,662 0.24 0.58 1.97 0.28 3.06 2.33 0.33 6.66
CB #02 CB #03 10,769 33,404 44,173 1.01 0.41 1.97 0.82 2.78 2.33 0.96 6.33
CB #03 CB #04 11,745 25,451 37,196 0.85 0.46 1.97 0.77 1.97 2.33 0.90 2.32
CB #04 CB #05 20,117 18,445 38,562 0.89 0.59 1.97 1.03 1.20 2.33 1.21 1.41
CB #05 CB #06 0 0 0 0.00 0.00 1.97 0.00 0.17 2.33 0.00 0.20
CB #06 CB #07 0 0 0 0.00 0.00 1.97 0.00 0.17 2.33 0.00 0.20
CB #07 CB #08 2,952 2,114 5,066 0.12 0.63 1.97 0.14 0.17 2.33 0.17 0.20
CB #08 CB #09 469 484 953 0.02 0.57 1.97 0.02 0.02 2.33 0.03 0.03
coterra
collaborative civil engineering + site development + infrastructure design
ENGINEERING PLLC
Project: Limelite Short Plat
Designed By: MEB
Checked By: PMA
Date: 8/15/2016
Rational Method - Time of Concetration Calculation
1. Calculate C average Value
# Type of Area Area (sf) C value C*A
1 Pavement and Roofs 10,769 0.9 9,692
2 Landscaping 33,404 0.25 8,351
Total 44,173 18,043
C (avg)=(Sum of AxC)/Total Area:0.41
2. Calculate Time of Concentration
Tc=L/(60*V) with V = KR(Slope)^.5
Reach # Type of Area Length (ft) Elev. Chg. (ft) Slope KR V (ft/sec) Tc (min)
1 Lawns 390 4 1.0%7 0.71 9.17
2 Bare Ground 80 1 1.3%10.1 1.13 1.18
2 Paved area 10 0.2 2.0%20 2.83 0.06
Total Tc=10.41
3. Calculate IR = (PR)*(iR)
Precipitation for 25yr =3.4 in
Precipitation for 100yr =3.9 in
aR = Coefficient from Table 3.2.1B
bR = Coefficient from Table 3.2.1B
Time of Concentration (min) = 10.40859573 (Minimum Time of Concentration is 6.3 minutes)
R aR Tc bR iR=(aR)(Tc)^(-bR P (in)IR(in)
25 year 2.66 10.408596 0.65 0.58 3.4 1.97
100 year 2.61 10.408596 0.63 0.60 3.9 2.33
4. Calculate Flow Q=Cavg* IR*Total Basin Area (ac)
R Cavg IR(in) Area (sf) Area (ac) Q (cfs)
25 year 0.41 1.97 44,173 1.01 0.82
100 year 0.41 2.33 44,173 1.01 0.96
RATIONAL METHODcoterra
collaborative civil engineering + site development + infrastructure design
ENGINEERING PLLC
Appendix D
Bond Quantity Calculation
Site Improvement Bond Quantity Worksheet Web date: 11/21/2005
Department of Development & Environmental Services
900 Oakesdale Avenue Southwest
Renton, Washington 98055-1219
206-296-6600 TTY 206-296-7217
Project Name: Date:
Location: Project No.:
Activity No.:
Note: All prices include labor, equipment, materials, overhead and
Clearing greater than or equal to 5,000 board feet of timber? profit. Prices are from RS Means data adjusted for the Seattle area
or from local sources if not included in the RS Means database.
_____________yes X no
If yes,
Forest Practice Permit Number:
(RCW 76.09)
Page 1 of 9
Limelite Short Plat
16204 114th AVE SE, RENTON, WA 98055
For alternate formats, call 206-296-6600.
__________________
8/15/2016
BONDQUANTITY_Permit_Final.xlsx
Unit prices updated: 02/12/02
Version: 04/22/02
Report Date: 8/15/2016
Site Improvement Bond Quantity Worksheet Web date: 11/21/2005
Unit # of
Reference #Price Unit Quantity Applications Cost
EROSION/SEDIMENT CONTROL Number
Backfill & compaction-embankment ESC-1 5.62$ CY
Check dams, 4" minus rock ESC-2 SWDM 5.4.6.3 67.51$ Each
Crushed surfacing 1 1/4" minus ESC-3 WSDOT 9-03.9(3) 85.45$ CY
Ditching ESC-4 8.08$ CY
Excavation-bulk ESC-5 1.50$ CY
Fence, silt ESC-6 SWDM 5.4.3.1 1.38$ LF 499 1 689
Fence, Temporary (NGPE)ESC-7 1.38$ LF
Hydroseeding ESC-8 SWDM 5.4.2.4 0.59$ SY 3323 1 1961
Jute Mesh ESC-9 SWDM 5.4.2.2 1.45$ SY
Mulch, by hand, straw, 3" deep ESC-10 SWDM 5.4.2.1 2.01$ SY 3323 1 6679
Mulch, by machine, straw, 2" deep ESC-11 SWDM 5.4.2.1 0.53$ SY
Piping, temporary, CPP, 6"ESC-12 10.70$ LF
Piping, temporary, CPP, 8"ESC-13 16.10$ LF
Piping, temporary, CPP, 12"ESC-14 20.70$ LF
Plastic covering, 6mm thick, sandbagged ESC-15 SWDM 5.4.2.3 2.30$ SY 5000 1 11500
Rip Rap, machine placed; slopes ESC-16 WSDOT 9-13.1(2) 39.08$ CY
Rock Construction Entrance, 50'x15'x1'ESC-17 SWDM 5.4.4.1 1,464.34$ Each 1 1 1464
Rock Construction Entrance, 100'x15'x1'ESC-18 SWDM 5.4.4.1 2,928.68$ Each
Sediment pond riser assembly ESC-19 SWDM 5.4.5.2 1,949.38$ Each
Sediment trap, 5' high berm ESC-20 SWDM 5.4.5.1 17.91$ LF
Sed. trap, 5' high, riprapped spillway berm section ESC-21 SWDM 5.4.5.1 68.54$ LF
Seeding, by hand ESC-22 SWDM 5.4.2.4 0.51$ SY
Sodding, 1" deep, level ground ESC-23 SWDM 5.4.2.5 6.03$ SY
Sodding, 1" deep, sloped ground ESC-24 SWDM 5.4.2.5 7.45$ SY
TESC Supervisor ESC-25 74.75$ HR
Water truck, dust control ESC-26 SWDM 5.4.7 97.75$ HR 10 1 978
WRITE-IN-ITEMS **** (see page 9)
50.00$ Each 10
ESC SUBTOTAL:23,270.26$
30% CONTINGENCY & MOBILIZATION:6,981.08$
ESC TOTAL:30,251.34$
COLUMN:A
Page 2 of 9
Catch Basin Protection
BONDQUANTITY_Permit_Final.xlsx
Unit prices updated: 02/12/02
Version: 04/22/02
Report Date: 8/15/2016
Site Improvement Bond Quantity Worksheet Web date: 11/21/2005
Existing Future Public Private
Right-of-Way Road Improvements Improvements
& Drainage Facilities Quant.
Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete Cost
GENERAL ITEMS No.
Backfill & Compaction- embankment GI - 1 5.62$ CY
Backfill & Compaction- trench GI - 2 8.53$ CY
Clear/Remove Brush, by hand GI - 3 0.36$ SY
Clearing/Grubbing/Tree Removal GI - 4 8,876.16$ Acre 0.687 6,097.92
Excavation - bulk GI - 5 1.50$ CY
Excavation - Trench GI - 6 4.06$ CY
Fencing, cedar, 6' high GI - 7 18.55$ LF
Fencing, chain link, vinyl coated, 6' high GI - 8 13.44$ LF
Fencing, chain link, gate, vinyl coated, 20' GI - 9 1,271.81$ Each
Fencing, split rail, 3' high GI - 10 12.12$ LF
Fill & compact - common barrow GI - 11 22.57$ CY 554 12,503.78
Fill & compact - gravel base GI - 12 25.48$ CY
Fill & compact - screened topsoil GI - 13 37.85$ CY
Gabion, 12" deep, stone filled mesh GI - 14 54.31$ SY
Gabion, 18" deep, stone filled mesh GI - 15 74.85$ SY
Gabion, 36" deep, stone filled mesh GI - 16 132.48$ SY
Grading, fine, by hand GI - 17 2.02$ SY
Grading, fine, with grader GI - 18 0.95$ SY
Monuments, 3' long GI - 19 135.13$ Each
Sensitive Areas Sign GI - 20 2.88$ Each
Sodding, 1" deep, sloped ground GI - 21 7.46$ SY
Surveying, line & grade GI - 22 788.26$ Day
Surveying, lot location/lines GI - 23 1,556.64$ Acre
Traffic control crew ( 2 flaggers ) GI - 24 85.18$ HR
Trail, 4" chipped wood GI - 25 7.59$ SY
Trail, 4" crushed cinder GI - 26 8.33$ SY
Trail, 4" top course GI - 27 8.19$ SY
Wall, retaining, concrete GI - 28 44.16$ SF
Wall, rockery GI - 29 9.49$ SF
Page 3 of 9 SUBTOTAL 18,601.70
Quantity Completed
(Bond Reduction)*
*KCC 27A authorizes only one bond reduction.
BONDQUANTITY_Permit_Final.xlsx
Unit prices updated: 02/12/02
Version: 4/22/02
Report Date: 8/15/2016
Site Improvement Bond Quantity Worksheet Web date: 11/21/2005
Existing Future Public Private Bond Reduction*
Right-of-way Road Improvements Improvements
& Drainage Facilities Quant.
Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete Cost
ROAD IMPROVEMENT No.
AC Grinding, 4' wide machine < 1000sy RI - 1 23.00$ SY
AC Grinding, 4' wide machine 1000-2000sy RI - 2 5.75$ SY
AC Grinding, 4' wide machine > 2000sy RI - 3 1.38$ SY
AC Removal/Disposal/Repair RI - 4 41.14$ SY
Barricade, type I RI - 5 30.03$ LF
Barricade, type III ( Permanent ) RI - 6 45.05$ LF
Curb & Gutter, rolled RI - 7 13.27$ LF
Curb & Gutter, vertical RI - 8 9.69$ LF 372 3,604.68
Curb and Gutter, demolition and disposal RI - 9 13.58$ LF
Curb, extruded asphalt RI - 10 2.44$ LF
Curb, extruded concrete RI - 11 2.56$ LF
Sawcut, asphalt, 3" depth RI - 12 1.85$ LF 770 1,424.50
Sawcut, concrete, per 1" depth RI - 13 1.69$ LF
Sealant, asphalt RI - 14 0.99$ LF
Shoulder, AC, ( see AC road unit price ) RI - 15 -$ SY
Shoulder, gravel, 4" thick RI - 16 7.53$ SY
Sidewalk, 4" thick RI - 17 30.52$ SY
Sidewalk, 4" thick, demolition and disposal RI - 18 27.73$ SY
Sidewalk, 5" thick RI - 19 34.94$ SY
Sidewalk, 5" thick, demolition and disposal RI - 20 34.65$ SY
Sign, handicap RI - 21 85.28$ Each
Striping, per stall RI - 22 5.82$ Each
Striping, thermoplastic, ( for crosswalk ) RI - 23 2.38$ SF
Striping, 4" reflectorized line RI - 24 0.25$ LF
Page 4 of 9 SUBTOTAL 5,029.18
*KCC 27A authorizes only one bond reduction.
BONDQUANTITY_Permit_Final.xlsx
Unit prices updated: 02/12/02
Version: 4/22/02
Report Date: 8/15/2016
Site Improvement Bond Quantity Worksheet Web date: 11/21/2005
Existing Future Public Private Bond Reduction*
Right-of-way Road Improvements Improvements
& Drainage Facilities Quant.
Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete Cost
ROAD SURFACING (4" Rock = 2.5 base & 1.5" top course) For '93 KCRS ( 6.5" Rock= 5" base & 1.5" top course)
For KCRS '93, (additional 2.5" base) add: RS - 1 3.60$ SY
AC Overlay, 1.5" AC RS - 2 7.39$ SY
AC Overlay, 2" AC RS - 3 8.75$ SY
AC Road, 2", 4" rock, First 2500 SY RS - 4 17.24$ SY
AC Road, 2", 4" rock, Qty. over 2500SY RS - 5 13.36$ SY
AC Road, 3", 4" rock, First 2500 SY RS - 6 19.69$ SY 520 10,238.80 390 7,679.10
AC Road, 3", 4" rock, Qty. over 2500 SY RS - 7 15.81$ SY
AC Road, 5", First 2500 SY RS - 8 14.57$ SY
AC Road, 5", Qty. Over 2500 SY RS - 9 13.94$ SY
AC Road, 6", First 2500 SY RS - 10 16.76$ SY
AC Road, 6", Qty. Over 2500 SY RS - 11 16.12$ SY
Asphalt Treated Base, 4" thick RS - 12 9.21$ SY
Gravel Road, 4" rock, First 2500 SY RS - 13 11.41$ SY
Gravel Road, 4" rock, Qty. over 2500 SY RS - 14 7.53$ SY
PCC Road, 5", no base, over 2500 SY RS - 15 21.51$ SY
PCC Road, 6", no base, over 2500 SY RS - 16 21.87$ SY
Thickened Edge RS - 17 6.89$ LF
Page 5 of 9 SUBTOTAL 10,238.80 7,679.10
*KCC 27A authorizes only one bond reduction.
BONDQUANTITY_Permit_Final.xlsx
Unit prices updated: 02/12/02
Version: 4/22/02
Report Date: 8/15/2016
Site Improvement Bond Quantity Worksheet Web date: 11/21/2005
Existing Future Public Private Bond Reduction*
Right-of-way Road Improvements Improvements
& Drainage Facilities Quant.
Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete Cost
DRAINAGE (CPP = Corrugated Plastic Pipe, N12 or Equivalent)For Culvert prices, Average of 4' cover was assumed. Assume perforated PVC is same price as solid pipe.
Access Road, R/D D - 1 16.74$ SY
Bollards - fixed D - 2 240.74$ Each
Bollards - removable D - 3 452.34$ Each
* (CBs include frame and lid)
CB Type I D - 4 1,257.64$ Each 7 8,803.48 7 8,803.48
CB Type IL D - 5 1,433.59$ Each
CB Type II, 48" diameter D - 6 2,033.57$ Each 3 6,100.71
for additional depth over 4' D - 7 436.52$ FT 3 1,309.56
CB Type II, 54" diameter D - 8 2,192.54$ Each 1 2,192.54
for additional depth over 4' D - 9 486.53$ FT 1 486.53
CB Type II, 60" diameter D - 10 2,351.52$ Each
for additional depth over 4' D - 11 536.54$ FT
CB Type II, 72" diameter D - 12 3,212.64$ Each
for additional depth over 4' D - 13 692.21$ FT
Through-curb Inlet Framework (Add) D - 14 366.09$ Each
Cleanout, PVC, 4" D - 15 130.55$ Each
Cleanout, PVC, 6" D - 16 174.90$ Each
Cleanout, PVC, 8" D - 17 224.19$ Each
Culvert, PVC, 4" D - 18 8.64$ LF
Culvert, PVC, 6" D - 19 12.60$ LF 40 504.00
Culvert, PVC, 8" D - 20 13.33$ LF 240 3,199.20
Culvert, PVC, 12" D - 21 21.77$ LF 926 20,159.02 34 740.18
Culvert, CMP, 8" D - 22 17.25$ LF
Culvert, CMP, 12" D - 23 26.45$ LF
Culvert, CMP, 15" D - 24 32.73$ LF
Culvert, CMP, 18" D - 25 37.74$ LF
Culvert, CMP, 24" D - 26 53.33$ LF
Culvert, CMP, 30" D - 27 71.45$ LF
Culvert, CMP, 36" D - 28 112.11$ LF
Culvert, CMP, 48" D - 29 140.83$ LF
Culvert, CMP, 60" D - 30 235.45$ LF
Culvert, CMP, 72" D - 31 302.58$ LF
Page 6 of 9 SUBTOTAL 36,372.77 15,925.93
*KCC 27A authorizes only one bond reduction.
BONDQUANTITY_Permit_Final.xlsx
Unit prices updated: 02/12/02
Version: 4/22/02
Report Date: 8/15/2016
Site Improvement Bond Quantity Worksheet Web date: 11/21/2005
Existing Future Public Private Bond Reduction*
Right-of-way Road Improvements Improvements
DRAINAGE CONTINUED & Drainage Facilities Quant.
No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Complete Cost
Culvert, Concrete, 8" D - 32 21.02$ LF
Culvert, Concrete, 12" D - 33 30.05$ LF
Culvert, Concrete, 15" D - 34 37.34$ LF
Culvert, Concrete, 18" D - 35 44.51$ LF
Culvert, Concrete, 24" D - 36 61.07$ LF
Culvert, Concrete, 30" D - 37 104.18$ LF
Culvert, Concrete, 36" D - 38 137.63$ LF
Culvert, Concrete, 42" D - 39 158.42$ LF
Culvert, Concrete, 48" D - 40 175.94$ LF
Culvert, CPP, 6" D - 41 10.70$ LF
Culvert, CPP, 8" D - 42 16.10$ LF
Culvert, CPP, 12" D - 43 20.70$ LF
Culvert, CPP, 15" D - 44 23.00$ LF
Culvert, CPP, 18" D - 45 27.60$ LF
Culvert, CPP, 24" D - 46 36.80$ LF
Culvert, CPP, 30" D - 47 48.30$ LF
Culvert, CPP, 36" D - 48 55.20$ LF
Ditching D - 49 8.08$ CY
Flow Dispersal Trench (1,436 base+) D - 50 25.99$ LF
French Drain (3' depth) D - 51 22.60$ LF
Geotextile, laid in trench, polypropylene D - 52 2.40$ SY
Infiltration pond testing D - 53 74.75$ HR
Mid-tank Access Riser, 48" dia, 6' deep D - 54 1,605.40$ Each 5 8027
Pond Overflow Spillway D - 55 14.01$ SY
Restrictor/Oil Separator, 12" D - 56 1,045.19$ Each
Restrictor/Oil Separator, 15" D - 57 1,095.56$ Each
Restrictor/Oil Separator, 18" D - 58 1,146.16$ Each
Riprap, placed D - 59 39.08$ CY
Tank End Reducer (36" diameter) D - 60 1,000.50$ Each 1 1000.5
Trash Rack, 12" D - 61 211.97$ Each
Trash Rack, 15" D - 62 237.27$ Each
Trash Rack, 18" D - 63 268.89$ Each
Trash Rack, 21" D - 64 306.84$ Each
Page 7 of 9 SUBTOTAL 9027.5
*KCC 27A authorizes only one bond reduction.
BONDQUANTITY_Permit_Final.xlsx
Unit prices updated: 02/12/02
Version: 4/22/02
Report Date: 8/15/2016
Site Improvement Bond Quantity Worksheet Web date: 11/21/2005
Existing Future Public Private Bond Reduction*
Right-of-way Road Improvements Improvements
& Drainage Facilities Quant.
Unit Price Unit Quant. Price Quant. Cost Quant. Cost Complete Cost
PARKING LOT SURFACING
No.
2" AC, 2" top course rock & 4" borrow PL - 1 15.84$ SY
2" AC, 1.5" top course & 2.5" base course PL - 2 17.24$ SY
4" select borrow PL - 3 4.55$ SY
1.5" top course rock & 2.5" base course PL - 4 11.41$ SY
WRITE-IN-ITEMS
(Such as detention/water quality vaults.)No.
Stormdrain HDPE - 8 inch WI - 1 40.00$ LF 280 11,200.00
Stormdrain HDPE - 12 inch WI - 3 50.00$ LF 35 1,750.00
Stormdrain HDPE - 78 inch detention pipe WI - 4 200.00$ LF 236 47,200.00
Sanitary Sewer pipe - 6 inch WI - 5 40.00$ LF 155 6,200.00
Water Pipe 1" including exc and backfill WI - 6 40.00$ LF 240 9,600.00
Water Meter WI - 7 2,000.00$ Each 5 10,000.00
Pervious Concrete Sidewalk WI - 8 50.00$ SY 230 11500
ADA Curb Ramp WI - 9 800.00$ Each 1 800
Concrete Driveway WI - 10 35.00$ SY 165 5775
WI - 11
WI - 12
SUBTOTAL 18,075.00 85,950.00
SUBTOTAL (SUM ALL PAGES):69,715.75 137,184.23
30% CONTINGENCY & MOBILIZATION:20,914.73 41,155.27
GRANDTOTAL:90,630.48 178,339.50
COLUMN: B C D E
Page 8 of 9
*KCC 27A authorizes only one bond reduction.
BONDQUANTITY_Permit_Final.xlsx
Unit prices updated: 02/12/02
Version: 4/22/02
Report Date: 8/15/2016
Site Improvement Bond Quantity Worksheet Web date: 11/21/2005
Original bond computations prepared by:
Name: Date:
PE Registration Number: Tel. #:
Firm Name:
Address: Project No:
Stabilization/Erosion Sediment Control (ESC) (A)
Existing Right-of-Way Improvements (B)
Future Public Road Improvements & Drainage Facilities (C)
Private Improvements (D)
Calculated Quantity Completed (E)
Total Right-of Way and/or Site Restoration Bond*/** (A+B)
(First $7,500 of bond* shall be cash.)
Performance Bond* Amount (A+B+C+D) = TOTAL (T) T x 0.30 OR
Minimum bond* amount is $1000.
Reduced Performance Bond* Total ***
Use larger of Tx30% or (T-E)
Maintenance/Defect Bond* Total
NAME OF PERSON PREPARING BOND* REDUCTION: Date:
* NOTE:The word "bond" as used in this document means any financial guarantee acceptable to King County.
** NOTE:KCC 27A authorizes right of way and site restoration bonds to be combined when both are required.
The restoration requirement shall include the total cost for all TESC as a minimum, not a maximum. In addition, corrective work, both on- and off-site needs to be included.
Quantities shall reflect worse case scenarios not just minimum requirements. For example, if a salmonid stream may be damaged, some estimated costs for restoration
needs to be reflected in this amount. The 30% contingency and mobilization costs are computed in this quantity.
*** NOTE:Per KCC 27A, total bond amounts remaining after reduction shall not be less than 30% of the original amount (T) or as revised by major design changes.
SURETY BOND RIDER NOTE: If a bond rider is used, minimum additional performance bond shall be (C+D)-E
REQUIRED BOND* AMOUNTS ARE SUBJECT TO REVIEW AND MODIFICATION BY DDES
178,339.5$
22,657.6$
299,221.3$
30,251.3$
(T-E)
90,630.5$
-$
89,766.4$
(B+C) x
0.25 =
120,881.8$
178,339.5$
299,221.3$
-$
8/15/2016
206-596-7115
ROAD IMPROVEMENTS & DRAINAGE FACILITIES FINANCIAL GUARANTEE REQUIREMENTS
PUBLIC ROAD & DRAINAGE
MAINTENANCE/DEFECT BOND*
Peter Apostol
Coterra Engineering
321 3rd Avenue South, Suite 406, Seattle, WA 98104
PERFORMANCE BOND*
AMOUNT
35163
BOND* AMOUNT
REQUIRED AT RECORDING OR
TEMPORARY OCCUPANCY ***
Page 9 of 9
BONDQUANTITY_Permit_Final.xlsx
Check out the DDES Web site at www.metrokc.gov/ddes
Unit prices updated: 02/12/02
Version: 4/22/02
Report Date: 8/15/2016
Appendix E
Declaration of Covenants
RECORDING REQUESTED BY AND
WHEN RECORDED MAIL TO:
CITY CLERK’S OFFICE
CITY OF RENTON
1055 SOUTH GRADY WAY
RENTON, WA 98057
DECLARATION OF COVENANT
FOR MAINTENANCE AND INSPECTION OF FLOW CONTROL BMPS
Grantor:
Grantee: City of Renton
Legal Description:
Additional Legal(s) on:
Assessor's Tax Parcel ID#:
IN CONSIDERATION of the approved City of Renton(check one of the following) residential
building permit, commercial building permit, clearing and grading permit, subdivision permit, or
short subdivision permit for Application File No. LUA/SWP ____________________ relating to the
real property ("Property") described above, the Grantor(s), the owner(s) in fee of that Property, hereby
covenants(covenant) with City or Renton, a political subdivision of the state of Washington, that
he/she(they) will observe, consent to, and abide by the conditions and obligations set forth and described
in Paragraphs 1 through 8 below with regard to the Property. Grantor(s) hereby grants(grant),
covenants(covenant), and agrees(agree) as follows:
1. Grantor(s) or his/her(their) successors in interest and assigns ("Owners") shall retain, uphold,
and protect the stormwater management devices, features, pathways, limits, and restrictions, known as
flow control best management practices ("BMPs"), shown on the approved Flow Control BMP Site Plan
for the Property attached hereto and incorporated herein as Exhibit A.
2. The Owners shall at their own cost, operate, maintain, and keep in good repair, the Property's
BMPs as described in the approved Design and Maintenance Details for each BMP attached hereto and
incorporated herein as Exhibit B.
3. City or Renton shall provide at least 30 days written notice to the Owners that entry on the
Property is planned for the inspection of the BMPs. After the 30 days, the Owners shall allow the City of
Renton to enter for the sole purpose of inspecting the BMPs. In lieu of inspection by the City, the
Owners may elect to engage a licensed civil engineer registered in the state of Washington who has
expertise in drainage to inspect the BMPs and provide a written report describing their condition. If the
engineer option is chosen, the Owners shall provide written notice to the City of Renton within fifteen
days of receiving the City's notice of inspection. Within 30 days of giving this notice, the Owners, or the
engineer on behalf of the Owners, shall provide the engineer's report to the City of Renton. If the report
is not provided in a timely manner as specified above, the City of Renton may inspect the BMPs without
further notice.
4. If the City determines from its inspection, or from an engineer's report provided in accordance
with Paragraph 3, that maintenance, repair, restoration, and/or mitigation work is required for the BMPs,
The City shall notify the Owners of the specific maintenance, repair, restoration, and/or mitigation work
(Work) required under RMC 4-6-030. The City shall also set a reasonable deadline for completing the
Work or providing an engineer's report that verifies completion of the Work. After the deadline has
passed, the Owners shall allow the City access to re-inspect the BMPs unless an engineer's report has
been provided verifying completion of the Work. If the work is not completed properly within the time
frame set by the City, the City may initiate an enforcement action. Failure to properly maintain the BMPs
is a violation of RMC 4-6-030 and may subject the Owners to enforcement under the RMC 1-3, including
fines and penalties.
5. Apart from performing routine landscape maintenance, the Owners are hereby required to
obtain written approval from the City or Renton before performing any alterations or modifications to the
BMPs.
6. Any notice or approval required to be given by one party to the other under the provisions of
this Declaration of Covenant shall be effective upon personal delivery to the other party, or after three (3)
days from the date that the notice or approval is mailed with delivery confirmation to the current address
on record with each Party. The parties shall notify each other of any change to their addresses.
7. This Declaration of Covenant is intended to promote the efficient and effective management of
surface water drainage on the Property, and it shall inure to the benefit of all the citizens of the City of
Renton and its successors and assigns. This Declaration of Covenant shall run with the land and be
binding upon Grantor(s), and Grantor's(s') successors in interest and assigns.
8. This Declaration of Covenant may be terminated by execution of a written agreement by the
Owners and the City of Renton that is recorded by King County in its real property records.
IN WITNESS WHEREOF, this Declaration of Covenant for the Maintenance and Inspection of
Flow Control BMPs is executed this _____ day of ____________________, 20_____.
GRANTOR, owner of the Property
GRANTOR, owner of the Property
STATE OF WASHINGTON ) COUNTY OF KING )ss.
On this day personally appeared before me:
, to me known to be the individual(s) described in
and who executed the within and foregoing instrument and acknowledged that they signed the same as
their free and voluntary act and deed, for the uses and purposes therein stated.
Given under my hand and official seal this _____ day of ____________________, 20_____.
Printed name
Notary Public in and for the State of Washington,
residing at
My appointment expires
Appendix F
Operation and Maintenance Manual
APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES
2009 Surface Water Design Manual – Appendix A 1/9/2009A-5
NO. 3 – DETENTION TANKS AND VAULTS
Maintenance
Component
Defect or Problem Conditions When Maintenance is Needed Results Expected When
Maintenance is Performed
Trash and debris Any trash and debris which exceed 1 cubic footper 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.
Trash and debris cleared from site.
Noxious weeds Any noxious or nuisance vegetation which may
constitute a hazard to County personnel or the
public.
Noxious and nuisance vegetation
removed according to applicable
regulations. No danger of noxious
vegetation where County personnelor the public might normally be.
Contaminants and
pollution
Any evidence of contaminants or pollution such
as oil, gasoline, concrete slurries or paint.
Materials removed and disposed of
according to applicable regulations.
Source control BMPs implemented if
appropriate. No contaminants
present other than a surface oil film.
Site
Grass/groundcover Grass or groundcover exceeds 18 inches in
height.
Grass or groundcover mowed to a
height no greater than 6 inches.
Trash and debris Any trash and debris accumulated in vault or tank
(includes floatables and non-floatables).
No trash or debris in vault.Tank or Vault
Storage Area
Sediment
accumulation
Accumulated sediment depth exceeds 10% of the
diameter of the storage area for ½ length of
storage vault or any point depth exceeds 15% of
diameter. Example: 72-inch storage tank would
require cleaning when sediment reaches depth of
7 inches for more than ½ length of tank.
All sediment removed from storage
area.
Plugged air vent Any blockage of the vent. Tank or vault freely vents.
Tank bent out ofshape Any part of tank/pipe is bent out of shape morethan 10% of its design shape.Tank repaired or replaced to design.
Tank Structure
Gaps between
sections, damaged
joints or cracks or
tears in wall
A gap wider than ½-inch at the joint of any tank
sections or any evidence of soil particles entering
the tank at a joint or through a wall.
No water or soil entering tank
through joints or walls.
Vault Structure Damage to wall,frame, bottom, and/or
top slab
Cracks wider than ½-inch, any evidence of soilentering the structure through cracks or qualified
inspection personnel determines that the vault is
not structurally sound.
Vault is sealed and structurallysound.
Sediment
accumulation
Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment.
Trash and debris Trash and debris accumulated in inlet/outlet
pipes (includes floatables and non-floatables).
No trash or debris in pipes.
Inlet/Outlet Pipes
Damaged Cracks wider than ½-inch at the joint of the
inlet/outlet pipes or any evidence of soil entering
at the joints of the inlet/outlet pipes.
No cracks more than ¼-inch wide at
the joint of the inlet/outlet pipe.
APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES
1/9/2009 2009 Surface Water Design Manual – Appendix AA-6
NO. 3 – DETENTION TANKS AND VAULTS
Maintenance
Component
Defect or Problem Conditions When Maintenance is Needed Results Expected When
Maintenance is Performed
Cover/lid not in place Cover/lid is missing or only partially in place.
Any open manhole requires immediate
maintenance.
Manhole access covered.
Locking mechanism
not working
Mechanism cannot be opened by one
maintenance person with proper tools. Bolts
cannot be seated. Self-locking cover/lid does not
work.
Mechanism opens with proper tools.
Cover/lid difficult to
remove
One maintenance person cannot remove
cover/lid after applying 80 lbs of lift.
Cover/lid can be removed and
reinstalled by one maintenance
person.
Access Manhole
Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards.
Allows maintenance person safe
access.
Damaged or difficult
to open
Large access doors or plates cannot be
opened/removed using normal equipment.
Replace or repair access door so it
can opened as designed.
Gaps, doesn't cover
completely
Large access doors not flat and/or access
opening not completely covered.
Doors close flat and covers access
opening completely.
Large access
doors/plate
Lifting Rings missing,
rusted
Lifting rings not capable of lifting weight of door
or plate.
Lifting rings sufficient to lift or
remove door or plate.
APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES
2009 Surface Water Design Manual – Appendix A 1/9/2009A-7
NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR
Maintenance
Component
Defect or Problem Condition When Maintenance is Needed Results Expected When
Maintenance is Performed
Trash or debris of more than ½ cubic foot whichis located immediately in front of the structure
opening or is blocking capacity of the structure by
more than 10%.
No Trash or debris blocking orpotentially blocking entrance to
structure.
Trash or debris in the structure that exceeds 1/3the depth from the bottom of basin to invert the
lowest pipe into or out of the basin.
No trash or debris in the structure.
Trash and debris
Deposits of garbage exceeding 1 cubic foot in
volume.
No condition present which would
attract or support the breeding of
insects or rodents.
Sediment Sediment exceeds 60% of the depth from the
bottom of the structure to the invert of the lowest
pipe into or out of the structure or the bottom of
the FROP-T section or is within 6 inches of the
invert of the lowest pipe into or out of thestructure or the bottom of the FROP-T section.
Sump of structure contains no
sediment.
Corner of frame extends more than ¾ inch past
curb face into the street (If applicable).
Frame is even with curb.
Top slab has holes larger than 2 square inches or
cracks wider than ¼ inch.
Top slab is free of holes and cracks.
Damage to frame
and/or top slab
Frame not sitting flush on top slab, i.e.,
separation of more than ¾ inch of the frame from
the top slab.
Frame is sitting flush on top slab.
Cracks wider than ½ inch and longer than 3 feet,
any evidence of soil particles entering structure
through cracks, or maintenance person judges
that structure is unsound.
Structure is sealed and structurally
sound.
Cracks in walls or
bottom
Cracks wider than ½ inch and longer than 1 foot
at the joint of any inlet/outlet pipe or any evidence
of soil particles entering structure through cracks.
No cracks more than 1/4 inch wide at
the joint of inlet/outlet pipe.
Settlement/
misalignment
Structure has settled more than 1 inch or has
rotated more than 2 inches out of alignment.
Basin replaced or repaired to design
standards.
Damaged pipe joints Cracks wider than ½-inch at the joint of the
inlet/outlet pipes or any evidence of soil entering
the structure at the joint of the inlet/outlet pipes.
No cracks more than ¼-inch wide at
the joint of inlet/outlet pipes.
Contaminants and
pollution
Any evidence of contaminants or pollution such
as oil, gasoline, concrete slurries or paint.
Materials removed and disposed of
according to applicable regulations.
Source control BMPs implemented if
appropriate. No contaminants
present other than a surface oil film.
Structure
Ladder rungs missingor unsafe Ladder is unsafe due to missing rungs,misalignment, rust, cracks, or sharp edges.Ladder meets design standards andallows maintenance person safe
access.
T section is not securely attached to structure
wall and outlet pipe structure should support at
least 1,000 lbs of up or down pressure.
T section securely attached to wall
and outlet pipe.
Structure is not in upright position (allow up to10% from plumb).Structure in correct position.
Connections to outlet pipe are not watertight or
show signs of deteriorated grout.
Connections to outlet pipe are water
tight; structure repaired or replaced
and works as designed.
FROP-T Section Damage
Any holes—other than designed holes—in the
structure.
Structure has no holes other than
designed holes.
Cleanout Gate Damaged or missing Cleanout gate is missing. Replace cleanout gate.
APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES
1/9/2009 2009 Surface Water Design Manual – Appendix AA-8
NO. 4 – CONTROL STRUCTURE/FLOW RESTRICTOR
Maintenance
Component
Defect or Problem Condition When Maintenance is Needed Results Expected When
Maintenance is Performed
Cleanout gate is not watertight. Gate is watertight and works asdesigned.
Gate cannot be moved up and down by one
maintenance person.
Gate moves up and down easily and
is watertight.
Chain/rod leading to gate is missing or damaged. Chain is in place and works as
designed.
Damaged or missing Control device is not working properly due to
missing, out of place, or bent orifice plate.
Plate is in place and works as
designed.
Orifice Plate
Obstructions Any trash, debris, sediment, or vegetation
blocking the plate.
Plate is free of all obstructions and
works as designed.
Obstructions Any trash or debris blocking (or having the
potential of blocking) the overflow pipe.
Pipe is free of all obstructions and
works as designed.
Overflow Pipe
Deformed or damaged
lip
Lip of overflow pipe is bent or deformed. Overflow pipe does not allow
overflow at an elevation lower than
design
Sediment
accumulation
Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment.
Trash and debris Trash and debris accumulated in inlet/outlet
pipes (includes floatables and non-floatables).
No trash or debris in pipes.
Inlet/Outlet Pipe
Damaged Cracks wider than ½-inch at the joint of the
inlet/outlet pipes or any evidence of soil enteringat the joints of the inlet/outlet pipes.
No cracks more than ¼-inch wide at
the joint of the inlet/outlet pipe.
Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets design
standards.
Trash and debris Trash and debris that is blocking more than 20%
of grate surface.
Grate free of trash and debris.
footnote to guidelines for disposal
Metal Grates
(If Applicable)
Damaged or missing Grate missing or broken member(s) of the grate. Grate is in place and meets design
standards.
Cover/lid not in place Cover/lid is missing or only partially in place.
Any open structure requires urgent
maintenance.
Cover/lid protects opening to
structure.
Locking mechanism
Not Working
Mechanism cannot be opened by one
maintenance person with proper tools. Boltscannot be seated. Self-locking cover/lid does not
work.
Mechanism opens with proper tools.
Manhole Cover/Lid
Cover/lid difficult toRemove One maintenance person cannot removecover/lid after applying 80 lbs. of lift.Cover/lid can be removed andreinstalled by one maintenance
person.
APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES
2009 Surface Water Design Manual – Appendix A 1/9/2009A-9
NO. 5 – CATCH BASINS AND MANHOLES
Maintenance
Component
Defect or Problem Condition When Maintenance is Needed Results Expected When
Maintenance is Performed
Sediment Sediment exceeds 60% of the depth from thebottom of the catch basin to the invert of the
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.
Sump of catch basin contains nosediment.
Trash or debris of more than ½ cubic foot which
is located immediately in front of the catch basin
opening or is blocking capacity of the catch basin
by more than 10%.
No Trash or debris blocking or
potentially blocking entrance to
catch basin.
Trash or debris in the catch basin that exceeds1/3 the depth from the bottom of basin to invert the
lowest pipe into or out of the basin.
No trash or debris in the catch basin.
Dead animals or vegetation that could generate
odors that could cause complaints or dangerous
gases (e.g., methane).
No dead animals or vegetation
present within catch basin.
Trash and debris
Deposits of garbage exceeding 1 cubic foot in
volume.
No condition present which would
attract or support the breeding of
insects or rodents.
Corner of frame extends more than ¾ inch past
curb face into the street (If applicable).
Frame is even with curb.
Top slab has holes larger than 2 square inches or
cracks wider than ¼ inch.
Top slab is free of holes and cracks.
Damage to frame
and/or top slab
Frame not sitting flush on top slab, i.e.,
separation of more than ¾ inch of the frame from
the top slab.
Frame is sitting flush on top slab.
Cracks wider than ½ inch and longer than 3 feet,
any evidence of soil particles entering catch
basin through cracks, or maintenance person
judges that catch basin is unsound.
Catch basin is sealed and
structurally sound.
Cracks in walls or
bottom
Cracks wider than ½ inch and longer than 1 foot
at the joint of any inlet/outlet pipe or any evidence
of soil particles entering catch basin through
cracks.
No cracks more than 1/4 inch wide at
the joint of inlet/outlet pipe.
Settlement/
misalignment
Catch basin has settled more than 1 inch or has
rotated more than 2 inches out of alignment.
Basin replaced or repaired to design
standards.
Damaged pipe joints Cracks wider than ½-inch at the joint of the
inlet/outlet pipes or any evidence of soil entering
the catch basin at the joint of the inlet/outlet
pipes.
No cracks more than ¼-inch wide at
the joint of inlet/outlet pipes.
Structure
Contaminants and
pollution
Any evidence of contaminants or pollution such
as oil, gasoline, concrete slurries or paint.
Materials removed and disposed of
according to applicable regulations.Source control BMPs implemented if
appropriate. No contaminants
present other than a surface oil film.
Sediment
accumulation
Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment.
Trash and debris Trash and debris accumulated in inlet/outletpipes (includes floatables and non-floatables).No trash or debris in pipes.
Inlet/Outlet Pipe
Damaged Cracks wider than ½-inch at the joint of the
inlet/outlet pipes or any evidence of soil entering
at the joints of the inlet/outlet pipes.
No cracks more than ¼-inch wide at
the joint of the inlet/outlet pipe.
APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES
1/9/2009 2009 Surface Water Design Manual – Appendix AA-10
NO. 5 – CATCH BASINS AND MANHOLES
Maintenance
Component
Defect or Problem Condition When Maintenance is Needed Results Expected When
Maintenance is Performed
Unsafe grate opening Grate with opening wider than 7/8 inch. Grate opening meets designstandards.
Trash and debris Trash and debris that is blocking more than 20%
of grate surface.
Grate free of trash and debris.
footnote to guidelines for disposal
Metal Grates(Catch Basins)
Damaged or missing Grate missing or broken member(s) of the grate.
Any open structure requires urgent
maintenance.
Grate is in place and meets design
standards.
Cover/lid not in place Cover/lid is missing or only partially in place.
Any open structure requires urgent
maintenance.
Cover/lid protects opening to
structure.
Locking mechanism
Not Working
Mechanism cannot be opened by one
maintenance person with proper tools. Bolts
cannot be seated. Self-locking cover/lid does not
work.
Mechanism opens with proper tools.
Manhole Cover/Lid
Cover/lid difficult to
Remove
One maintenance person cannot remove
cover/lid after applying 80 lbs. of lift.
Cover/lid can be removed and
reinstalled by one maintenance
person.
APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES
2009 Surface Water Design Manual – Appendix A 1/9/2009A-11
NO. 6 – CONVEYANCE PIPES AND DITCHES
Maintenance
Component
Defect or Problem Conditions When Maintenance is Needed Results Expected When
Maintenance is Performed
Sediment & debrisaccumulation Accumulated sediment or debris that exceeds20% of the diameter of the pipe.Water flows freely through pipes.
Vegetation/roots Vegetation/roots that reduce free movement of
water through pipes.
Water flows freely through pipes.
Contaminants and
pollution
Any evidence of contaminants or pollution such
as oil, gasoline, concrete slurries or paint.
Materials removed and disposed of
according to applicable regulations.
Source control BMPs implemented if
appropriate. No contaminants
present other than a surface oil film.
Damage to protective
coating or corrosion
Protective coating is damaged; rust or corrosion
is weakening the structural integrity of any part of
pipe.
Pipe repaired or replaced.
Pipes
Damaged Any dent that decreases the cross section area of
pipe by more than 20% or is determined to have
weakened structural integrity of the pipe.
Pipe repaired or replaced.
Trash and debris Trash and debris exceeds 1 cubic foot per 1,000
square feet of ditch and slopes.
Trash and debris cleared from
ditches.
Sediment
accumulation
Accumulated sediment that exceeds 20% of the
design depth.
Ditch cleaned/flushed of all sediment
and debris so that it matches design.
Noxious weeds Any noxious or nuisance vegetation which may
constitute a hazard to County personnel or thepublic.
Noxious and nuisance vegetation
removed according to applicableregulations. No danger of noxious
vegetation where County personnel
or the public might normally be.
Contaminants and
pollution
Any evidence of contaminants or pollution such
as oil, gasoline, concrete slurries or paint.
Materials removed and disposed of
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
through ditches.
Water flows freely through ditches.
Erosion damage to
slopes
Any erosion observed on a ditch slope. Slopes are not eroding.
Ditches
Rock lining out of
place or missing (If
Applicable)
One layer or less of rock exists above native soil
area 5 square feet or more, any exposed native
soil.
Replace rocks to design standards.
APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES
1/9/2009 2009 Surface Water Design Manual – Appendix AA-12
NO. 7 – DEBRIS BARRIERS (E.G., TRASH RACKS)
Maintenance
Component
Defect or Problem Condition When Maintenance is Needed Results Expected When
Maintenance is Performed.
Trash and debris Trash or debris plugging more than 20% of thearea of the barrier.Barrier clear to receive capacity flow.Site
Sediment
accumulation
Sediment accumulation of greater than 20% of
the area of the barrier
Barrier clear to receive capacity flow.
Structure Cracked broken or
loose
Structure which bars attached to is damaged -
pipe is loose or cracked or concrete structure is
cracked, broken of loose.
Structure barrier attached to is
sound.
Bar spacing Bar spacing exceeds 6 inches. Bars have at most 6 inche spacing.
Bars are bent out of shape more than 3 inches. Bars in place with no bends more
than ¾ inch.
Bars are missing or entire barrier missing. Bars in place according to design.
Bars
Damaged or missing
bars
Bars are loose and rust is causing 50%
deterioration to any part of barrier.
Repair or replace barrier to design
standards.
APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES
2009 Surface Water Design Manual – Appendix A 1/9/2009A-13
NO. 8 – ENERGY DISSIPATERS
Maintenance
Component
Defect or Problem Conditions When Maintenance is Needed Results Expected When
Maintenance is Performed.
Trash and debris Trash and/or debris accumulation. Dissipater clear of trash and/ordebris.Site
Contaminants and
pollution
Any evidence of contaminants or pollution such
as oil, gasoline, concrete slurries or paint.
Materials removed and disposed of
according to applicable regulations.
Source control BMPs implemented if
appropriate. No contaminants
present other than a surface oil film.
Rock Pad Missing or moved
Rock
Only one layer of rock exists above native soil in
area five square feet or larger or any exposure of
native soil.
Rock pad prevents erosion.
Pipe plugged with
sediment
Accumulated sediment that exceeds 20% of the
design depth.
Pipe cleaned/flushed so that it
matches design.
Not discharging water
properly
Visual evidence of water discharging at
concentrated points along trench (normal
condition is a “sheet flow” of water along trench).
Water discharges from feature by
sheet flow.
Perforations plugged. Over 1/4 of perforations in pipe are plugged with
debris or sediment.
Perforations freely discharge flow.
Water flows out top of
“distributor” catch
basin.
Water flows out of distributor catch basin during
any storm less than the design storm.
No flow discharges from distributor
catch basin.
Dispersion Trench
Receiving area over-saturated Water in receiving area is causing or haspotential of causing landslide problems.No danger of landslides.
Damaged mesh Mesh of gabion broken, twisted or deformed so
structure is weakened or rock may fall out.
Mesh is intact, no rock missing.
Corrosion Gabion mesh shows corrosion through more than
¼ of its gage.
All gabion mesh capable of
containing rock and retaining
designed form.
Collapsed or
deformed baskets
Gabion basket shape deformed due to any
cause.
All gabion baskets intact, structure
stands as designed.
Gabions
Missing rock Any rock missing that could cause gabion to
loose structural integrity.
No rock missing.
Worn or damaged
post, baffles or side of
chamber
Structure dissipating flow deteriorates to ½ or
original size or any concentrated worn spot
exceeding one square foot which would make
structure unsound.
Structure is in no danger of failing.
Damage to wall,
frame, bottom, and/or
top slab
Cracks wider than ½-inch or any evidence of soil
entering the structure through cracks, or
maintenance inspection personnel determines
that the structure is not structurally sound.
Manhole/chamber is sealed and
structurally sound.
Manhole/Chamber
Damaged pipe joints Cracks wider than ½-inch at the joint of the
inlet/outlet pipes or any evidence of soil entering
the structure at the joint of the inlet/outlet pipes.
No soil or water enters and no water
discharges at the joint of inlet/outlet
pipes.
Appendix G
Geotechnical Report
________________________________________________
3213 Eastlake Avenue East, Suite B
Seattle, WA 98102
(206) 262-0370
Geotechnical & Earthquake
Engineering Consultants
June 24, 2014
Project No. 14-052
Mr. Todd Karam
Limelite Development
14508 NE 20th Street, Suite 200
Bellevue, WA 98007
Subject: Geotechnical Engineering Report
Proposed Short Plat and Development
16204 – 114th Avenue SE, Renton, Washington
Dear Mr. Karam,
As requested, PanGEO, Inc. completed a geotechnical engineering study to assist you and
your project team with the proposed short plat and development at the above-referenced
property. This study was performed in accordance with our mutually agreed scope of work
as outlined in our proposal dated March 4, 2014, and was subsequently approved by you on
the same day. Our service scope included reviewing readily available geologic data,
conducting a site reconnaissance, excavating five test pits, and developing the conclusions
and recommendations presented in this report.
SITE AND PROJECT DESCRIPTION
The subject property is an approximately 29,900 square foot lot located at 16204 – 114th
Avenue SE in the City of Renton, Washington (see Figure 1, Vicinity Map). The subject lot
is roughly rectangular in shape, and is bordered to the north by SE 162nd Street, to the west
by 114th Avenue SE, and to the east and south by existing single-family residences (see
Figure 2, Site and Exploration Plan). An existing single-family residence occupies the
central portion of the site (see Plates 1 and 2 on Page 2 and Figure 2). A detached garage is
located in the southeastern corner of the lot. The site is covered with short grass with
several mature trees at the time of our field exploration. The existing site grade is generally
level.
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 2 PanGEO, Inc.
We understand that you plan to remove the existing house and garage, and to subdivide the
property into five single-family residential lots. Details regarding the short plat and future
building design information are currently not available. We envisage that the proposed
single-family residences will be wood frame, two- to three-story structures with attached
garages. New private roads or driveways will also be constructed to provide access to the
proposed residences. Additionally, new utilities will also be needed for the proposed
development. We anticipate that site grading for the proposed construction will likely
include cuts and fill on the order of 4 feet for the foundation construction, and may be as
deep as 7 to 8 feet for the utility construction.
The conclusions and recommendations outlined in this report are based on our
understanding of the proposed development at this time, which is in turn based on the
project information provided. If the above project description is substantially different from
your proposed improvements or if the project scope changes, PanGEO should be consulted
to review the recommendations contained in this report and make modifications, if needed.
SUBSURFACE EXPLORATION
Five test pits (TP-1 through TP-5) were excavated at the site on March 19, 2014, to explore
the general subsurface conditions at the site. The approximate test pit locations were taped
from existing site features and are indicated on Figure 2. The test pits were excavated to
depths of about 7 to 8 feet below the existing ground surface using an excavator owned and
Plate 1. Partial view of the site showing the house
and garage, looking east from 114th Avenue NE.
Plate 2. Partial site view showing the house,
looking northwest from SE 162nd Street.
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 3 PanGEO, Inc.
operated by Northwest Excavating, Inc., out of Mill Creek, Washington. A geologist from
PanGEO was present during the field exploration to observe the test pit excavations, obtain
representative samples, and to describe and document the soils encountered in the
explorations. The soils encountered during our subsurface exploration were described and
field classified in general accordance with the symbols and terms outlined in Figure A-1 in
Appendix A of this report. Summary test pit logs are included as Figures A-2 through A-6.
The relative in-situ density of cohesionless soils, or the relative consistency of fine-grained
soils was estimated from the excavating action of the back-hoe, and the stability of the test
pit sidewalls. Where soil contacts were gradual or undulating, the average depth of the
contact was recorded in the logs. After each test pit was logged, the excavation was
backfilled with the excavated soils and the surface was tamped and re-graded smooth.
SUBSURFACE CONDITIONS
SITE GEOLOGY
According to the geology maps of the area (The Geologic Map of King County,
Washington: scale 1:100,000, Booth, D. B., Troost, K. A., and Wisher, A. P., 2007), the
project area is underlain by Vashon Glacial Till (Qvt). Glacial Till deposit (Qvt) is described
by Troost, et al, as a very dense, heterogeneous mixture of silt, sand, and gravel laid down at
the base of an advancing glacial ice sheet.
SOIL
In summary, our test pits generally encountered three distinctive soil units: (1) topsoil/fill,
(2) till-like deposits, and (3) sandstone. A summary description of these soil units are
summarized below:
Unit 1: Fill – Our test pits encountered about 1 to 5 feet of gray to brown, moist, loose
to medium dense silty sand and sandy silt with trace to some gravel and occasional
organics. We interpret this surface unit as fill due to its disturbed appearance and
presence of organics.
Unit 2: Till-Like Deposits – Below the topsoil/fill, the test pits encountered medium
dense to dense, moist to wet, gravelly silty sand. This unit appeared to be till-like
deposits and is weathered at the upper portion with iron oxide stains. This unit
extended to the maximum depths of the test pits TP-2 through TP-5 at about 7 to 8 feet
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 4 PanGEO, Inc.
below the surface. This unit extended to about 7 feet in TP-1. Coal interbeds were
encountered at about 7 feet in test pit TP-2 and 4 to 8 feet in TP-4. Coal interbeds were
not encountered in other test pits.
Unit 3: Sandstone – Underlying the till-like deposits in TP-1, very dense, gray
sandstone was encountered from 7 to 8 feet, the maximum depth excavated. This unit
is not encountered in other test pit locations within the excavation depths.
GROUNDWATER
Moderate to heavy groundwater seepage was encountered in all test pits at depths of about 1
to 5 feet below the surface at the time of our subsurface exploration. The groundwater
seepage is perched above the dense till. It should be noted that groundwater elevations and
seepage rates are likely to vary depending on the season, local subsurface conditions, and
other factors. Groundwater levels are normally highest during the winter and early spring.
GEOLOGIC HAZARDS ASSESSMENT
As part of our study, we evaluated potential geologic hazards at the subject site as defined in
Renton Municipal Code (RMC) Section 4-3-050 (Critical Areas Regulations). The City of
Renton identifies five different types of Geologic Hazards: Steep Slopes; Landslide Hazards;
Erosion Hazards; Seismic Hazards; and Coal Mine Hazards. Based on review of the City of
Renton’s sensitive areas maps, the site is not mapped within steep slope, erosion, landslide,
and coal mine hazard areas. Potentially liquefiable soils were not encountered at our
exploration locations; and therefore, the site does not meet the criteria for seismic hazard.
Since the site is flat and there are no steep slopes in the site vicinity, and the site does not
contain potentially liquefiable soil, only the erosion and coal mine hazards are further
discussed in the following sections:
EROSION HAZARDS
The site is not mapped as a high erosion hazard area by the City of Renton. Based on the
test pits excavated at the site, it is our opinion the site soils exhibit low erosion potential. In
our opinion, any potential erosion hazards at the site can be effectively mitigated with the
best management practice during construction and with properly designed and implemented
landscaping and permanent erosion control measures. During construction, the temporary
erosion hazard can also be effectively managed with an appropriate erosion and sediment
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 5 PanGEO, Inc.
control plan, including but not limited to installing silt fence at the construction perimeter,
placing rocks or hay bales at the disturbed and traffic areas, covering stockpile soil or cut
slopes with plastic sheets, constructing a temporary drainage pond to control surface runoff
and sediment trap, placing rocks at the construction entrance, etc.
Permanent erosion control measures should be applied to the disturbed areas as soon as
feasible. These measures may include but not limited to planting and hydroseeding. The
use of permanent erosion control mat may also be considered in conjunction with
planting/hydroseeding to protect the soils from erosion.
COAL MINE HAZARDS
City of Renton contains abandoned coal mines in several areas that can have potentially
adverse impacts on site development. As part of our study, we reviewed information
contained in the Washington State Coal Mine Map Collection: A Catalog, Index, and Users
Guide, Open File Report 94-7, prepared by the Washington Division of Geology and Earth
Resources (DNR 1994), the Washington State Coal Mine Map Collection
(http://www.dnr.wa.gov/ResearchScience/Topics/GeologyPublicationsLibrary/Pages/coalmaps.
aspx) and the City of Renton Coal Mine Map (Renton 2012) for information pertaining to
historic coal mining operations in the vicinity of the site.
According to City of Renton’s Sensitive Area map, the subject site is not mapped as a Coal
Mine hazard area. However, an area with Moderate Coal Mine Hazards Designation was
mapped about 2 blocks northwest of the site. Based on our review, two mines operated
within the section containing the subject site (Township 23 North, Range 5 East, Section
29). These mines are identified as the Sunbeam Mine and the Renton Mine. However, these
mines appear to be located at least two blocks to the north and northwest of the subject site,
and do not extend below the subject property.
During our field exploration and site reconnaissance, we did not observe any surface or
subsurface indications of coal mining activity, such as mine tailing piles, abandoned mine
openings, or abandoned mining equipment, all of which are typically found near coal mine
operations. Based on the results of our review, in our opinion, the subject site is not directly
underlain by coal mine workings and would have a Low Coal Mine Hazard designation.
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 6 PanGEO, Inc.
GEOTECHNICAL RECOMENDATIONS
GENERAL
Based on the results of our study, in our opinion, the proposed short plat and development at
the subject site is feasible from a geotechnical engineering standpoint, provided the
geotechnical engineering recommendations contained in this report are followed. The
principal geotechnical engineering considerations for the proposed residential project
include the following:
Requirements for site preparation.
Building foundation subgrade support requirement and design parameters; and
Excavations, excavation support, and dewatering considerations for the building and
utility construction;
Detailed discussion of these items and our geotechnical engineering design
recommendations are presented in the following sections of this report.
EARTHWORK RECOMMENDATIONS
Site Preparation
Site preparation includes striping and clearing of surface vegetation, and excavating to the
design subgrade. Site preparation should begin with the removal of surface vegetation
within the proposed improvement areas (i.e. building pads, roadway, and driveway), and
excavating to the design subgrade. Based on our site exploration, we anticipate stripping
depths will be about 12 inches at the site. Organic rich silt/clay soil and other deleterious
materials, if encountered during stripping, should also be removed as part of stripping
operation. All stripped surface materials should be properly disposed off-site or be “wasted”
on site in non-structural landscaping areas.
Following site stripping/clearing and excavation, the exposed soil should be proof-rolled
with a minimum 10-ton steel roller or a fully loaded dump truck. Soft/loose and pumping
subgrade detected during proof-rolling operation should be over-excavated and backfilled
with structural fill. The proof-rolling operation should be observed by a representative of
PanGEO.
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 7 PanGEO, Inc.
Material Reuse
Based on the test pits excavated at the site, it is our opinion that the on-site silty sand should
not be re-used as a source of structural fill and backfill. However, they can be used as
general fill in the non-structural areas. If use of the existing soils is planned, any excavated
soil should be stockpiled and protected with plastic sheeting to prevent wetting and
softening from rainfall.
Structural Fill and Compaction
In the context of this report, structural fill is defined as compacted fill placed under building
foundations, roadways, slabs, pavements, or other load-bearing areas. Structural fill should
consist of imported, well-graded granular material, such as WSDOT Crushing Surface Base
Course or approved equivalent. Well-graded recycled concrete aggregates may also be
considered as a source of structural fill. Use of recycled concrete as structural fill should be
approved by the geotechnical engineer.
Structural fill soils should be moisture conditioned to within about 3 percent of optimum
moisture content, placed in loose, horizontal lifts less than 8 inches in thickness, and
compacted to at least 95 percent maximum density, determined using ASTM D 1557
(Modified Proctor). The procedure to achieve proper density of a compacted fill depends on
the size and type of compacting equipment, the number of passes, thickness of the layer
being compacted, and certain soil properties. In areas where the size of the excavation
restricts the use of heavy equipment, smaller equipment can be used, but the soil must be
placed in thin enough layers to achieve the required relative compaction.
Temporary Excavations and Temporary/Permanent Slopes
We anticipate that excavations for the building construction will be about 3 feet. However,
excavations up to about 7 and 8 feet may be needed for the utility construction. In general,
we anticipate excavations to encounter loose to medium dense fill and dense glacial till.
All temporary excavations should be performed in accordance with Part N of WAC
(Washington Administrative Code) 296-155. The contractor is responsible for maintaining
safe excavation slopes and/or shoring. Excavations more than 4 feet deep should be
properly shored or sloped. For planning purposes, it is our opinion that temporary
excavations may be sloped as steep as 1H:1V in the fill and ½H:1V or flatter in the till.
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 8 PanGEO, Inc.
The temporary excavations and cut slopes should be re-evaluated in the field during
construction based on actual observed soil conditions, and may need to be flattered in the
wet reasons. The cut slopes should be covered with plastic sheets in the raining season. We
also recommend that heavy construction equipment, building materials, excavated soil, and
vehicular traffic should not be allowed within a distance equal to 1/3 the slope height from
the top of any excavation.
Permanent cut and fill slopes should be graded no steeper than 2H:1V. Erosion control
measures such as erosion-control mats and/or vegetation’s should be applied to the
permanent slopes as soon as feasible.
Construction Dewatering
Because perched groundwater seepage was encountered at 1 to 5 feet below the existing
grade in the test pits during our field exploration, the contractor should be prepared to
provide construction dewatering systems in the wet season. Based on our understanding of
the project and site conditions, we anticipate that a conventional dewatering system
consisting of sumps and pumps will be adequate to dewater the temporary excavation.
SEISMIC DESIGN PARAMETERS
The Table 1 below provides seismic design parameters for the site that are in conformance
with the 2012 edition of the International Building Code (IBC), which specifies a design
earthquake having a 2% probability of occurrence in 50 years (return interval of 2,475
years). The spectral response accelerations were obtained from the USGS Earthquake
Hazards Program’s Seismic Design Maps and Tools website for the project latitude and
longitude.
Table 1 – Summary Seismic Design Parameters per 2012 IBC
Site Class
Spectral
Acceleration at
0.2 sec. (g)
SS
Spectral
Acceleration
at 1.0 sec. (g)
S1
Site Coefficients
Design Spectral
Response
Parameters
Fa Fv SDS SD1
D 1.402 0.523 1.0 1.50 0.935 0.523
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 9 PanGEO, Inc.
BUILDING FOUNDATIONS
Foundation Type and Allowable Bearing Pressure
Based on the subsurface conditions encountered at the site and our understanding of the
project development, it is our opinion that the proposed single-family buildings may be
supported on conventional spread and continuous footings bearing on the native till and/or
on newly placed structural fill on native till. Any topsoil/fill below the footings should be
over-excavated and backfilled with compacted structural fill. We anticipate that over-
excavation on the order of 1 to 2 feet may be needed in some areas to reach bearing soil.
We recommend that an allowable soil bearing pressure of 2,500 pounds per square feet (psf)
be used for sizing the footings. The recommended allowable bearing pressure is for dead
plus live loads. For allowable stress design, the recommended bearing pressure may be
increased by one-third for transient loading, such as wind or seismic forces. Continuous and
individual spread footings should have minimum widths of 18 and 24 inches, respectively.
Footing Embedment
Exterior footings should be placed at a minimum depth of 18 inches below final exterior
grade. Interior spread foundations should be placed at a minimum depth of 12 inches below
the top of slab.
Foundation Performance
Footings designed and constructed in accordance with the above recommendations should
experience total settlement of less than one inch and differential settlement of less than ½
inch. Most of the anticipated settlement should occur during construction as dead loads are
applied.
Lateral Resistance
Lateral loads on the structures may be resisted by passive earth pressure developed against
the embedded faces of the foundation system and by frictional resistance between the
bottom of the foundation and the supporting subgrade soils. For footings bearing on the
dense native soil or compacted sand/structural fill, a frictional coefficient of 0.35 may be
used to evaluate sliding resistance developed between the concrete and the compacted
subgrade soil. Passive soil resistance may be calculated using an equivalent fluid weight of
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 10 PanGEO, Inc.
300 pcf, assuming properly compacted structural fill will be placed against the footings.
The above values include a factor of safety of 1.5. Unless covered by pavements or slabs,
the passive resistance in the upper 12 inches of soil should be neglected.
Perimeter Footing Drains
Footing drains should be installed around the perimeter of the buildings, at or just below the
invert of the footings. Under no circumstances should roof downspout drain lines be con-
nected to the footing drain systems. Roof downspouts must be separately tightlined to
appropriate discharge locations. Cleanouts should be installed at strategic locations to allow
for periodic maintenance of the footing drain and downspout tightline systems.
Footing Excavation and Subgrade Preparation
All footing excavations should be trimmed neat and footing subgrades should be carefully
prepared. Any loose or softened soil should be removed from the footing excavations. The
footing subgrade may need to be recompacted to a dense, unyielding condition using a
jumping jack or other heavy compaction equipment, prior to form setting and rebar
placement. The adequacy of footing subgrade should be verified by a representative of
PanGEO, prior to placing forms or rebar. If the on-site native sandy soil is still loose and
yielding after re-compaction, they should be over-excavated to expose the bearing soil. The
over-excavation should be backfilled with compacted structural fill or lean-mix concrete.
The over-excavation width should extend at least one-half the over-excavation depth beyond
the edge of footing.
CONCRETE SLAB ON GRADE FLOORS
Concrete slab-on-grade floors may be used for the project and should be supported on on-
site silty sand compacted to a firm and unyielding condition or on newly placed structural
fill. Any loose/soft soil at the slab subgrade level should be over-excavated to expose
firm/dense soil and backfilled with compacted structural fill.
Slab-on-grade floors should be underlain by a capillary break consisting of at least of 4
inches of ¾-inch, clean crushed rock (less than 3 percent fines) compacted to a firm and
unyielding condition. The capillary break should be placed on subgrade that has been
compacted to a dense and unyielding condition. A 10-mil polyethylene vapor barrier should
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 11 PanGEO, Inc.
also be placed directly below the slab. We also recommend that control joints be
incorporated into the floor slab to control cracking.
Underslab Drains – Based on our test pits at the site, perched groundwater seepage may be
present near the proposed finished floor elevations. As such, we recommend installing an
under-slab drainage system below the slab-on-grade floor. The under-slab drainage system
should consist of 4-inch diameter perforated drainpipes placed in narrow (one foot or less),
approximately 18-inch deep trenches (measured from the bottom of slab) spaced no more
than about 20 feet apart. The under-slab drain trenches should be backfilled with clean,
free-draining 3/8 inch minus pea gravel. Water collected in these drainpipes should be
discharged to an appropriate outlet.
CONCRETE RETAINING AND BASEMENT WALLS
Retaining and basement walls, if needed, should be properly designed to resist the lateral
earth pressures exerted by the soils behind the wall. Proper drainage provisions should also
be provided behind the walls to intercept and remove groundwater that may be present
behind the wall. Our geotechnical recommendations for the design and construction of the
retaining/basement walls are presented below.
Lateral Earth Pressures
Concrete cantilever walls should be designed for an equivalent fluid pressure of 35 pcf for
level backfills behind the walls assuming the walls are free to rotate. If walls are to be
restrained at the top from free movement, such as basement walls, equivalent fluid pressures
of 45 pcf should be used for level backfills behind the walls. Walls with a maximum 2H:1V
backslope should be designed for an active and at rest earth pressure of 45 and 55 pcf,
respectively.
Permanent walls should be designed for an additional uniform lateral pressure of 7H psf for
seismic loading, where H corresponds to the buried depth of the wall. The recommended
lateral pressures assume that the backfill behind the wall consists of a free draining and
properly compacted fill with adequate drainage provisions.
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 12 PanGEO, Inc.
Surcharge
Surcharge loads, where present, should also be included in the design of retaining walls. We
recommend that a lateral load coefficient of 0.3 be used to compute the lateral pressure on
the wall face resulting from surcharge loads located within a horizontal distance of one-half
wall height.
Lateral Resistance
Lateral forces from seismic loading and unbalanced lateral earth pressures may be resisted
by a combination of passive earth pressures acting against the embedded portions of the
foundations and by friction acting on the base of the foundations. Passive resistance values
may be determined using an equivalent fluid weight of 300 pcf. This value includes a factor
of safety of 1.5, assuming the footing is poured against dense native sand, re-compacted on-
site sandy soil or properly compacted structural fill adjacent to the sides of footing. A
friction coefficient of 0.35 may be used to determine the frictional resistance at the base of
the footings. The coefficient includes a factor safety of 1.5.
Wall Drainage
Provisions for wall drainage should consist of a 4-inch diameter perforated drainpipe behind
and at the base of the wall footings, embedded in 12 to 18 inches of clean crushed rock and
pea gravel wrapped with a layer of filter fabric. A minimum 18-inch wide zone of free
draining granular soils (i.e. pea gravel or washed rock) is recommended to be placed
adjacent to the wall for the full height of the wall. Alternatively, a composite drainage
material, such as Miradrain 6000, may be used in lieu of the clean crushed rock or pea
gravel. The drainpipe at the base of the wall should be graded to direct water to a suitable
outlet.
The exterior of all basement walls should be protected with a damp proofing compound.
We also recommend the designers consider utilizing a waterproofing material, such as
prefabricated clay mats, on the exterior of all below grade walls to reduce the potential for
moisture intrusion into the below-grade portion of the building.
Wall Backfill
In our opinion, the relatively clean on-site sandy soil may be re-used as wall backfill.
Imported wall backfill, if needed, should consist of granular material, such as WSDOT
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 13 PanGEO, Inc.
Gravel Borrow or approved equivalent. In areas where the space is limited between the wall
and the face of excavation, pea gravel or clean crushed rock may be used as backfill without
compaction.
Wall backfill should be moisture conditioned to within about 3 percent of optimum moisture
content, placed in loose, horizontal lifts less than 8 inches in thickness, and systematically
compacted to a dense and relatively unyielding condition and to at least 95 percent of the
maximum dry density, as determined using test method ASTM D 1557. Within 5 feet of the
wall, the backfill should be compacted with hand-operated equipment to at least 90 percent
of the maximum dry density.
WET WEATHER EARTHWORK
In our opinion, the proposed site construction may be accomplished during wet weather
(such as in winter) without adversely affecting the site stability. However, earthwork
construction performed during the drier summer months likely will be more economical.
Winter construction will require the implementation of best management erosion and
sedimentation control practices to reduce the chance of off-site sediment transport. Some of
the site soils contain a high percentage of fines and are moisture sensitive. Any footing
subgrade soils that become softened either by disturbance or rainfall should be removed and
replaced with structural fill, Controlled Density Fill (CDF), or lean-mix concrete. General
recommendations relative to earthwork performed in wet conditions are presented below:
Site stripping, excavation and subgrade preparation should be followed promptly by
the placement and compaction of clean structural fill or CDF;
The size and type of construction equipment used may have to be limited to prevent
soil disturbance;
The ground surface within the construction area should be graded to promote run-off
of surface water and to prevent the ponding of water;
Geotextile silt fences should be strategically located to control erosion and the
movement of soil;
Structural fill should consist of less than 5% fines; and
Excavation slopes should be covered with plastic sheets.
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 14 PanGEO, Inc.
SURFACE DRAINAGE AND EROSION CONSIDERATIONS
Surface runoff can be controlled during construction by careful grading practices.
Typically, this includes the construction of shallow, upgrade perimeter ditches or low
earthen berms in conjunction with silt fences to collect runoff and prevent water from
entering excavations or to prevent runoff from the construction area from leaving the
immediate work site. Temporary erosion control may require the use of hay bales on the
downhill side of the project to prevent water from leaving the site and potential storm water
detention to trap sand and silt before the water is discharged to a suitable outlet.
Permanent control of surface water should be incorporated in the final grading design.
Adequate surface gradients and drainage systems should be incorporated into the design
such that surface runoff is directed away from structures. Potential problems associated
with erosion may also be reduced by establishing vegetation within disturbed areas
immediately following grading operations. Water form roof drains should be properly
collected and discharged.
ADDITIONAL SERVICES
To confirm that our recommendations are properly incorporated into the design and
construction of the proposed project, PanGEO should be retained to conduct a review of the
final project plans and specifications, and to monitor the construction of geotechnical
elements. The City of Renton, as part of the permitting process, will also require
geotechnical construction inspection services. PanGEO can provide you a cost estimate for
construction monitoring services at a later date.
We anticipate that the following additional services will be required:
Review final project plans and specifications
Monitor excavations and site stability
Verify adequacy of foundation bearing
Verify subsurface drainage installation (i.e. footing drains)
Verify structural fill compaction
Review of erosion control measures during construction
Other consultation as may be required during construction
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 15 PanGEO, Inc.
Modifications to our recommendations presented in this report may be necessary, based on
the actual conditions encountered during construction.
CLOSURE
We have prepared this report for use by Limelite Development and the project design team.
Recommendations contained in this report are based on a site reconnaissance, a subsurface
exploration program, a review of pertinent subsurface information, and our understanding of
the project. The study was performed using a mutually agreed-upon scope of work.
Variations in soil conditions may exist at locations away from the explorations. The nature
and extent of the soil variations may not be evident until construction occurs. If any soil
conditions are encountered at the site that are different from those described in this report,
we should be immediately notified to review the applicability of our recommendations.
Additionally, we should also be notified to review the applicability of our recommendations
if there are any changes in the project scope.
The scope of our work does not include services related to construction safety precautions.
Our recommendations are not intended to direct the contractors’ methods, techniques,
sequences or procedures, except as specifically described in our report for consideration in
design. Additionally, the scope of our work specifically excludes the assessment of site
environmental characteristics, particularly those involving hazardous substances. We are
not mold consultants nor are our recommendations to be interpreted as being preventative of
mold development. A mold specialist should be consulted for all mold-related issues.
This report has been prepared for planning and design purposes for specific application to
the proposed project in accordance with the generally accepted standards of local practice at
the time this report was written. No warranty, express or implied, is made.
This report may be used only by the client and for the purposes stated, within a reasonable
time from its issuance. Land use, site conditions (both off and on-site), or other factors
including advances in our understanding of applied science, may change over time and
could materially affect our findings. Therefore, this report should not be relied upon after 24
months from its issuance. PanGEO should be notified if the project is delayed by more than
24 months from the date of this report so that we may review the applicability of our
conclusions considering the time lapse.
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 16 PanGEO, Inc.
It is the client’s responsibility to see that all parties to this project, including the designer,
contractor, subcontractors, etc., are made aware of this report in its entirety. The use of
information contained in this report for bidding purposes should be done at the contractor’s
option and risk. Any party other than the client who wishes to use this report shall notify
PanGEO of such intended use and for permission to copy this report. Based on the intended
use of the report, PanGEO may require that additional work be performed and that an
updated report be reissued. Noncompliance with any of these requirements will release
PanGEO from any liability resulting from the use this report.
Please call if there are any questions on this report.
Sincerely,
Michael H. Xue, P.E. Siew L. Tan, P.E. Senior Geotechnical Engineer Principal Geotechnical Engineer
Enclosures:
Figure 1 Vicinity Map
Figure 2 Site and Exploration Plan
Appendix A: Summary Test Pit Logs
Figure A-1 Terms and Symbols for Boring and Test Pit Logs
Figures A-2 thru A-6 Logs of Test Pits TP-1 through TP-5
Geotechnical Engineering Report
Proposed Short Plat and Development: 16204 – 114th Avenue SE, Renton, WA
June 24, 2014
14-052 16204 - 114th Ave SE Rpt 17 PanGEO, Inc.
REFERENCES
Booth, D. B., Troost, K. A., and Wisher, A. P., 2007, The Geologic Map of King County,
Washington: scale 1:100,000.
City of Renton, 2012; Sensitive Area Map: City of Renton.
International Code Council, 2012, International Building Code (IBC).
Schasse, Henry W.; Koler, M. Lorraine; Eberle, Nancy A.; Christie, Rebecca A., 1994; The
Washington State coal mine map collection--A catalog, index, and user's guide:
Washington Division of Geology and Earth Resources Open File Report 94-7, 109 p.
WSDOT, 2014, Standard Specifications for Road, Bridges, and Municipal Construction.
14-052
Proposed Short Plat
and Development
16204 - 114th Ave SE
Renton, WA 1
VICINITY MAP
Figure 1.grf 6/23/14 (15:05)Note: Basemap obtained and modified from Google Maps.
Not to Scale
Figure No.Project No.
Project Location
Proposed Short Plat and Development16204 - 114th Ave SERenton, WashingtonSITE AND EXPLORATION PLAN14-052212-095 Site Plan Fig 2.grf 6/23/14 (14:56) SHE Legend: PanGEO Test PitTP-1Drawing based on Site Survey by GeoDimentions, dated Jan 20, 2014.Approx. Scale 1"=30'Project No. Figure No.TP-1TP-2TP-3TP-4TP-5Property Line Lot 3 Lot 4 Lot 5 Lot 1 Lot 2 Existing HouseExisting Garage
APPENDIX A
SUMMARY TEST PIT LOGS
MOISTURE CONTENT
2-inch OD Split Spoon, SPT
(140-lb. hammer, 30" drop)
3.25-inch OD Spilt Spoon
(300-lb hammer, 30" drop)
Non-standard penetration
test (see boring log for details)
Thin wall (Shelby) tube
Grab
Rock core
Vane Shear
Dusty, dry to the touch
Damp but no visible water
Visible free water
Terms and Symbols for
Boring and Test Pit Logs
Density
SILT / CLAY
GRAVEL (<5% fines)
GRAVEL (>12% fines)
SAND (<5% fines)
SAND (>12% fines)
Liquid Limit < 50
Liquid Limit > 50
Breaks along defined planes
Fracture planes that are polished or glossy
Angular soil lumps that resist breakdown
Soil that is broken and mixed
Less than one per foot
More than one per foot
Angle between bedding plane and a planenormal to core axis
Very Loose
Loose
Med. Dense
Dense
Very Dense
SPTN-values Approx. Undrained ShearStrength (psf)
<4
4 to 10
10 to 30
30 to 50
>50
<2
2 to 4
4 to 8
8 to 15
15 to 30
>30
SPTN-values
Units of material distinguished by color and/orcomposition from material units above and below
Layers of soil typically 0.05 to 1mm thick, max. 1 cm
Layer of soil that pinches out laterally
Alternating layers of differing soil material
Erratic, discontinuous deposit of limited extent
Soil with uniform color and composition throughout
Approx. RelativeDensity (%)
Gravel
Layered:
Laminated:
Lens:
Interlayered:
Pocket:
Homogeneous:
Highly Organic Soils
#4 to #10 sieve (4.5 to 2.0 mm)
#10 to #40 sieve (2.0 to 0.42 mm)
#40 to #200 sieve (0.42 to 0.074 mm)
0.074 to 0.002 mm
<0.002 mm
UNIFIED SOIL CLASSIFICATION SYSTEM
MAJOR DIVISIONS GROUP DESCRIPTIONS
Notes:
MONITORING WELL
<15
15 - 35
35 - 65
65 - 85
85 - 100
GW
GP
GM
GC
SW
SP
SM
SC
ML
CL
OL
MH
CH
OH
PT
TEST SYMBOLS
50%or more passing #200 sieve
Groundwater Level at time of drilling (ATD)Static Groundwater Level
Cement / Concrete Seal
Bentonite grout / seal
Silica sand backfill
Slotted tip
Slough
<250
250 - 500
500 - 1000
1000 - 2000
2000 - 4000
>4000
RELATIVE DENSITY / CONSISTENCY
Fissured:
Slickensided:
Blocky:
Disrupted:
Scattered:
Numerous:
BCN:
COMPONENT DEFINITIONS
Dry
Moist
Wet
1. Soil exploration logs contain material descriptions based on visual observation and field tests using a systemmodified from the Uniform Soil Classification System (USCS). Where necessary laboratory tests have beenconducted (as noted in the "Other Tests" column), unit descriptions may include a classification. Please refer to thediscussions in the report text for a more complete description of the subsurface conditions.
2. The graphic symbols given above are not inclusive of all symbols that may appear on the borehole logs.Other symbols may be used where field observations indicated mixed soil constituents or dual constituent materials.
COMPONENT SIZE / SIEVE RANGE COMPONENT SIZE / SIEVE RANGE
SYMBOLS
Sample/In Situ test types and intervals
Silt and Clay
Consistency
SAND / GRAVEL
Very Soft
Soft
Med. Stiff
Stiff
Very Stiff
Hard
Phone: 206.262.0370
Bottom of BoringBoulder:
Cobbles:
Gravel
Coarse Gravel:
Fine Gravel:
Sand
Coarse Sand:
Medium Sand:
Fine Sand:
Silt
Clay
> 12 inches
3 to 12 inches
3 to 3/4 inches
3/4 inches to #4 sieve
Figure A-1
Atterberg Limit Test
Compaction Tests
Consolidation
Dry Density
Direct Shear
Fines Content
Grain Size
Permeability
Pocket Penetrometer
R-value
Specific Gravity
Torvane
Triaxial Compression
Unconfined Compression
Sand
50% or more of the coarsefraction passing the #4 sieve.Use dual symbols (eg. SP-SM)for 5% to 12% fines.
for In Situ and Laboratory Testslisted in "Other Tests" column.
50% or more of the coarsefraction retained on the #4sieve. Use dual symbols (eg.GP-GM) for 5% to 12% fines.
DESCRIPTIONS OF SOIL STRUCTURES
Well-graded GRAVEL
Poorly-graded GRAVEL
Silty GRAVEL
Clayey GRAVEL
Well-graded SAND
Poorly-graded SAND
Silty SAND
Clayey SAND
SILT
Lean CLAY
Organic SILT or CLAY
Elastic SILT
Fat CLAY
Organic SILT or CLAY
PEAT
ATT
Comp
Con
DD
DS
%F
GS
Perm
PP
R
SG
TV
TXC
UCC
LOG KEY 13-104_LOGS.GPJ PANGEO.GDT 6/18/13
14-052 16204 - 114th Ave SE Rpt A-2 PanGEO, Inc.
Test Pit No. 1
Approximate ground surface elevation (feet): 480
Surface Conditions: Sod
Location: NW portion of the site (see Figure 2)
Depth (ft) Material Description
0 – 2 8 to 12 inches of sod over loose to medium dense, moist, brown silty
SAND (SM); trace gravel and occasional organics (Topsoil/Fill)
-Moderate to heavy groundwater seepage at 2 feet (perched
groundwater)
2 – 7 Medium dense to dense, moist to wet, tan-gray, gravelly silty SAND
(SM); top of unit is weathered, iron oxide stained (Till-Like Deposits)
7 – 8 Very dense, moist, gray, cemented SAND; (Sandstone)
Plate 1 below shows TP-1 at
approximately 8-feet in depth
TP-2 was terminated approximately 8 feet below ground surface.
Perched groundwater was observed at 2 feet at the time of the excavation.
14-052 16204 - 114th Ave SE Rpt A-3 PanGEO, Inc.
Test Pit No. 2
Approximate ground surface elevation (feet): 481
Surface Conditions: Sod
Location: NE corner of the site (see Figure 2)
Depth (ft) Material Description
0 – 5 6 to 8 inches of sod over loose to medium dense, moist, dark brown,
silty SAND/sandy SILT (SM/ML); gravel and occasional organics
(Topsoil/Fill)
- Moderate to heavy groundwater seepage at 1½ to 5 feet (perched
groundwater)
5 – 8 Medium dense to dense, moist to wet, tan-gray, gravelly silty SAND
(SM); top of unit is weathered, iron oxide stained ( Till-Like Deposits)
- At 7 feet, inter-beds of coal and till-like soil
Plate 2 below shows TP-2 at approximately 8-feet in depth.
Moderate caving was observed from
around 1½ to 5 feet.
TP-2 was terminated approximately 8 feet below ground surface.
Perched groundwater was observed from 1½ to 5 feet at the time of the excavation.
14-052 16204 - 114th Ave SE Rpt A-4 PanGEO, Inc.
Test Pit No. 3
Approximate ground surface elevation (feet): 481
Surface Conditions: Sod
Location: South portion of the site (see Figure 2)
Depth (ft) Material Description
0 – 3 8 inches of sod over loose, moist, gray-brown silty SAND (SM);
occasional gravel and organics (Topsoil/Fill)
- Groundwater seepage at 1 to 3 feet (perched groundwater)
3 – 7 Dense, moist, tan-gray, gravelly silty SAND (SM); top of unit is
weathered, iron oxide stained ( Till-Like Deposits)
Plate 3 below shows TP-3 at
approximately 7-feet in depth.
Moderate caving was observed
from around 1½ to 3 feet.
TP-3 was terminated
approximately 7 feet below
ground surface.
Perched groundwater was
observed from 1 to 3 feet at the
time of the excavation.
14-052 16204 - 114th Ave SE Rpt A-5 PanGEO, Inc.
Test Pit No. 4
Approximate ground surface elevation (feet): 481½
Surface Conditions: Sod
Location: NE of the house (see Figure 2)
Depth (ft) Material Description
0 – 1 8 inches of sod over loose to medium dense, moist, dark brown, silty
SAND/sandy SILT (SM/ML); gravel and occasional organics
(Topsoil/Fill)
1 – 8 Medium dense to dense, moist to wet, tan-gray, gravelly silty SAND
(SM); top of unit is weathered, iron oxide stained, with wet sand seams
( Till-Like Deposits)
- Groundwater seepage at 1 to 3 feet (perched groundwater)
- From 4 to 8 feet, inter-beds of coal and till-like soil
Plate 4 below shows TP-4 at approximately 8-feet in depth.
Plate 5 below shows coal excavated at around 6-feet in depth.
TP-4 was terminated approximately
8 feet below ground surface.
Perched groundwater was observed
from 1 to 3 feet at the time of the
excavation.
14-052 16204 - 114th Ave SE Rpt A-6 PanGEO, Inc.
Date of Test Pit excavations: March 19, 2014
Test Pits Logged by: NER
Test Pit No. 5
Approximate ground surface elevation (feet): 480
Surface Conditions: Sod
Location: SW portion of the site (see Figure 2)
Depth (ft) Material Description
0 – 1 12 inches of loose, moist, gray-brown silty SAND (SM); occasional
gravel and organics (Topsoil)
- Moderate to heavy groundwater seepage at 1 to 3 feet (perched
groundwater)
- To the south of the test pit, an area drain was observed at a depth of
around 3 feet
1 – 7½ Medium dense to dense, moist, tan-gray, gravelly silty SAND (SM);
top of unit is weathered, iron oxide stained ( Till-Like Deposits)
Plate 6 below shows TP-3 at approximately 7-feet in depth.
Moderate caving was observed from
around 1 to 3 feet on south side of
excavation.
TP-5 was terminated approximately
7½ feet below ground surface.
Perched groundwater was observed
from 1 to 3 feet at the time of the
excavation.