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HomeMy WebLinkAboutRS_TIR_20210331_v2DEVELOPMENT ENGINEERING
Nathan Janders 05/03/2021
SURFACE WATER UTILITY
jfarah 05/04/2021
MITCHELL SHORT PLAT
i
JOB #20-250
Technical Information Report
TABLE OF CONTENTS
PROJECT OVERVIEW ............................................................................................ 1.1
Existing Conditions Exhibit .......................................................................................... 1.3
Developed Conditions Exhibit ..................................................................................... 1.4
CONDITIONS AND REQUIREMENTS SUMMARY .................................................... 2.1
OFFSITE ANALYSIS ............................................................................................... 3.1
FLOW CONTROL AND WATER QUALITY ANALYSIS AND DESIGN ........................... 4.1
Hydraulic Analysis ...................................................................................................... 4.1
Existing Conditions ..................................................................................................... 4.1
Developed Conditions ................................................................................................. 4.3
Low Impact Development BMPs ................................................................................. 4.6
Water Quality Analysis and Design ............................................................................. 4.7
CONVEYANCE DESIGN ......................................................................................... 5.1
Storm Pipe Conveyance .............................................................................................. 5.1
SPECIAL REPORTS AND STUDIES .......................................................................... 6.1
OTHER PERMITS .................................................................................................. 7.1
TESC ANALYSIS AND DESIGN ................................................................................ 8.1
BOND QUANTITIES, FACILITIES SUMMARY, AND DECLARATION OF COVENANT ... 9.1
OPERATIONS AND MAINTENANCE .................................................................. 10.1
APPENDIX
A.Excerpt from Preliminary Mitchell Short Plat report with Level 1 Downstream Analysis
prepared by Goldsmith Land Development Services dated January 2020
B.Full WWHM Report Output – Detention Exemption
MITCHELL SHORT PLAT
1.1JOB #20-250
Technical Information Report
Project Overview
The project is located at 3625 Meadow Avenue North, Renton WA 98007. More generally, the site is located in
NW ¼ of Section 32, Township 24 N, Range 5 E, W.M.
Refer to the Existing & Developed Conditions Exhibits
included on the following pages. The project proposes to
develop 0.49-acres of a single 0.92-acre parcel (#334270-
0480) with 0.01-acres of frontage improvements along
Meadow Ave N leaving 0.43-acres of the parcel
undisturbed. The site contains an existing single-family
residence, gravel/asphalt driveway, a detached garage,
miscellaneous hardscape, lawn, residential landscaping.
Majority of the existing gravel and asphalt driveway will be
removed. Onsite runoff is generated from one drainage
basin. The site’s drainage basin is part of the May Creek
drainage basin and is ultimately tributary to the Lake
Washington. Refer to the Level 1 Downstream Analysis
included in the Section 3 and the Appendix of this report
for reference.
Per the USDA Web Soil Survey, soils are by Indianola loamy
sand (InD) also classified as outwash, which is consistent with the Site Development Geotechnical
Recommendations letter prepared by Mud Bay Geotechnical Services LLC dated January 29, 2020. The outwash
soils onsite are considered suitable for foundation support and for infiltration of site stormwater. A copy of the
Site Development Geotechnical Recommendations letter is provided in Section 6 of this report. See Section 4.3
for more information regarding Flow Control BMPs.
The site is bounded on the north, south, and west by single family residences and Meadow Ave N to the east.
This project will provide the necessary site improvements required to serve the two single family lots proposed
with this short plat. The existing residence and portion of gravel driveway will remain, and a new single-family
residence will be constructed east of the existing building. Proposed improvements will include utilities,
driveway improvements, site grading for the new home, and on-site stormwater management BMP’s. Refer to
the Developed Conditions Exhibit included at the end of this section.
Stormwater elements will be designed in accordance with the 2017 City of Renton Surface Water Design Manual
(COR SWDM). The subject site is in a Peak Rate Flow Control Standard (Existing Site Conditions) area. The
proposed development will create less than a 0.15 cfs increase in site runoff over the existing, predeveloped
condition for the 100-year storm event when modeled using 15-minute time step in WWHM2012. The targeted
basin is therefore exempt from detention requirements per Section 1.2.3.1 of the 2017 COR SWDM. The site
proposes 5,205 sf of targeted new plus replaced pollution generating impervious surface (PGIS) which is more
than the 5,000 sf threshold and is therefore subject to Basic Water Quality requirements per Chapter 1, Section
1.2.8 of the 2017 COR SWDM. The project proposes to treat stormwater runoff from the proposed road and
onsite driveways utilizing a treatment liner beneath the proposed permeable pavement, as detailed in Section 4
of this report. Stormwater Low Impact Development (LID) features will be provided to the maximum extent
feasible per Section 1.2.9.2.1. Please see Section 4 for the LID BMP, Flow Control, and Water Quality design
Vicinity Map-not to scale
MITCHELL SHORT PLAT
1.2JOB #20-250
Technical Information Report
consideration and subsequent discussion. The project is subject to Full Drainage Review per Section 1.1.2.4 of
the COR SWDM. The requirements for the Full Drainage Review are listed in Section 2.
MITCHELL SHORT PLAT
2.1JOB #20-250
Technical Information Report
Conditions and Requirements Summary
Core and special requirements as listed in Section 1.2 of the 2017 COR SWDM are listed below. The project is
subject to Full Drainage Review. The requirements for the Full Drainage Review are listed below.
CORE REQUIREMENT #1: DISCHARGE AT THE NATURAL LOCATION
See Section 3. In the existing condition, onsite runoff is generated from one drainage basins. Onsite runoff from
generally sheet flows north east across the subject parcel towards Meadow Ave N. Flows continue to sheet flow
north along Meadow Ave N before entering the tightlined storm system in Meadow Ave N that continues north
and west, ultimately discharging to Lake. The proposed conditions will not alter the general downstream path.
The proposed drainage improvements will continue to treat runoff within the property to the maximum extent
feasible via infiltration before discharging towards Meadow Ave N.
CORE REQUIREMENT #2: OFF-SITE ANALYSIS
See Section 3. A Level 1 Downstream Analysis excerpted from Mitchell Preliminary Short Plat report prepared by
Goldsmith Land Development Services dated January 2020 is included in the Appendix of the report.
CORE REQUIREMENT #3: FLOW CONTROL
See Section 4. According to the City of Renton Flow Control Application Map, included on the following pages,
the project is located in a Peak Rate Flow Control Standard (Existing Site Conditions) area. The site proposes to
treat runoff from onsite improvements via infiltration facilities. No tightline connection to the public conveyance
system is proposed for this project. Based on the scope of the site improvements the project is exempt from
providing flow control facilities. The increase in the peak developed condition runoff rate relative to the existing
site condition is less than 0.15 cfs (based on continuous modeling with a 15 minute time step); therefore, based
on the evaluation provided in Section 4, the project is exempt from requiring flow control.
CORE REQUIREMENT #4: CONVEYANCE SYSTEM
See Section 5. The conveyance system is designed per the 2017 COR SWDM to convey the 100-year, 24-hour
storm event without overtopping.
CORE REQUIREMENT #5: EROSION AND SEDIMENT CONTROL
See Section 8. The temporary erosion and sedimentation control (TESC) plan consists of temporary measures
(rock entrance, inlet protection, silt fence, etc.) as well as permanent measures (hydroseeding and landscaping).
CORE REQUIREMENT #6: OPERATIONS AND MAINTENANCE
See Section 10. Maintenance and operations information will be provided for the proposed private stormwater facilities.
Drainage utilities in the public right-of-way (ROW) and public easements will be maintained by the City of Renton.
MITCHELL SHORT PLAT
2.2JOB #20-250
Technical Information Report
CORE REQUIREMENT #7: FINANCIAL GUARANTEES AND LIABILITY
See Section 9. A City of Renton Bond Quantity Worksheet is included with this submittal.
CORE REQUIREMENT #8: WATER QUALITY
See Section 4. The project proposes more than the 5,000 sf of pollution generating impervious surfaces (PGIS)
and is therefore triggering water quality requirements per Section 1.2.8 of the 2017 COR SWDM. The project will
provide a treatment liner under the proposed permeable pavement to meet these requirements.
CORE REQUIREMENT #9: FLOW CONTROL BMPS
Please refer to Section 4 of this report for information on BMP feasibility analysis.
Special Requirement #1: Other Adopted Area-Specific Requirements
There are no known additional requirements for the subject project.
Special Requirement #2: Floodplain/Floodway
The subject site does not contain and is not adjacent to a flood hazard area. This Special Requirement is
therefore, not applicable.
Special Requirement #3: Flood Protection Facilities
The subject site does not rely on an existing flood protection facility and will not modify or construct a new flood
protection facility. This Special Requirement is therefore, not applicable.
Special Requirement #4: Source Control
The subject project is a residential development and not a commercial development. This Special Requirement is
not applicable.
Special Requirement #5: Oil Control
The subject project is a single-family development and not a high-use development. This Special Requirement,
therefore, is not applicable.
Special Requirement #6: Aquifer Protection Area
The subject project is not within an Aquifer Protection Area, therefore, this Special Requirement is not
applicable.
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Flow Control Application Map
Reference 15-A
Date: 01/09/2014
Flow Control Standards
Peak Rate Flow Control Standard (Existing Site Conditions)
Flow Control Duration Standard (Existing Site Conditions)
Flow Control Duration Standard (Forested Conditions)
Flood Problem Flow
Unincorporated King County Flow Control Standards
Renton City Limits
Potential Annexation Area
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MITCHELL SHORT PLAT
3.1JOB #20-250
Technical Information Report
Offsite Analysis
A Level 1 Downstream Analysis was prepared at the preliminary short plat submittal by Goldsmith Land
Development Services completed for the subject property. Blueline has reviewed the report by Goldsmith land
Development Services and agrees with the assessment. A copy of the Level 1 Downstream Analysis excerpted
from the Mitchell Preliminary Short Plat report prepared by Goldsmith Land Development Services dated
January 2020 is included in the Appendix of the report.
MITCHELL SHORT PLAT
4.1JOB #20-250
Technical Information Report
Flow Control and Water Quality Analysis and Design
Impervious coverage less driveways from Lot 2 will be collected and routed to full infiltration trenches. Onsite
proposed road and driveways providing access to lots will utilize permeable surfacing. The only improvements
proposed on Lot 1 is constructing a driveway transition from the access tract to the existing Lot 1 driveway.
Refer to the Developed Conditions Exhibit included in Section 1. An Offsite Analysis is included in Section 3 of
this report.
HYDRAULIC ANALYSIS
The drainage analysis was modeled using the Western Washington Hydrology Model software with 15-minute
time steps in accordance with the 2017 COR SWDM. Per the Site Development Geotechnical Recommendations
letter prepared by Mud Bay Geotechnical Services LLC, the soils observed in the test pits are considered suitable
for foundation support and for infiltration of site stormwater. The site has gentle to moderate slopes. The
project was modeled with the following parameters:
Rainfall Region: Seatac Scale Factor: 1.0
EXISTING CONDITIONS
The existing basin boundary area is 0.93 acres. The project consists of the parcel, 0.92 acres, and improvements
within the frontage along Meadow Ave N, 0.01 acres. In general, drainage from the site sheet flows northeast
towards Meadow Ave N. Runoff travels north along Meadow Ave N before being collected by the public
stormwater system within meadow Ave N. Runoff is part of the May Creek drainage basin. The site contains an
existing single-family residence, gravel/asphalt driveway, a detached garage, miscellaneous hardscape, lawn,
residential landscaping. A portion of the existing gravel and asphalt driveway will be removed. The existing
residence, detached garage, walkways, and decks will remain undisturbed, as such, will not be included in the
site threshold discharge area. Please see the Existing Conditions Exhibit in Section 1.
The site lies within a Peak Rate Flow Control Standard (Existing Site Conditions) area which dictates the
predeveloped condition be modeled as the existing site conditions. The areas used to compute the drainage
calculations associated with the existing basin conditions, as well as the corresponding WWHM output, are
summarized on the following pages of this report. Refer to the Appendix of this report for the full WWHM pdf
output.
MITCHELL SHORT PLAT
4.2JOB #20-250
Technical Information Report
EXISTING CONDITIONS
Impervious
Existing House 0.03 ac
Existing Garage 0.01 ac
Existing Gravel Access 0.10 ac
Existing Walkways 0.01 ac
Existing Frontage 0.01 ac
Total Impervious 0.16 ac
Lawn
Onsite Lawn 0.76 ac
Frontage Lawn 0.01 ac
Total Lawn (Till - Soil Group C)0.77 ac
TOTAL EXISTING CONDITIONS 0.93 ac
Flow Frequency Return Periods for Predeveloped. POC #1
Return Period Flow(cfs)
2 year 0.128267
5 year 0.197117
10 year 0.249117
25 year 0.322107
50 year 0.381809
100 year 0.446122
MITCHELL SHORT PLAT
4.3JOB #20-250
Technical Information Report
DEVELOPED CONDITIONS
The project proposes dividing the existing 0.92-acre lot into 2 single-family lots with an access tract and
dedicating right-of-way. The only improvements proposed on Lot 1 is constructing a driveway transition from
the access tract to the existing Lot 1 driveway. Access to the project will be provided via a private road accessing
from Meadow Ave N.
In the developed condition, the project proposes to develop 0.49-acres of a single 0.92-acre with 0.01-acres of
frontage improvements along Meadow Ave N, leaving 0.43-acres of the parcel undisturbed. For drainage
calculations, lots are assumed to have 55% impervious surface area per City of Renton residential R-6 zone
according to Renton Municipal Code 4-2-110. Lot 2 impervious coverage less driveway is proposed to be
collected, routed to onsite infiltration trenches, and utilize limited infiltration per findings of the geotechnical
evaluation included in Section 6 of this report. The proposed access will be made up of permeable surfacing,
therefore, permeable surfacing will be modeled as 50/50, grass/impervious per Table 1.2.9A of the 2017 COR
SWDM. Please refer to the Developed Conditions Exhibit in Section 1 of the report. The areas used to compute
the drainage calculations associated with the developed conditions, as well as the corresponding WWHM
output, are summarized below. Refer to the Appendix of this report for the full WWHM pdf output.
DEVELOPED CONDITIONS
Impervious
Lot 1 Impervious*0.22 ac
Lot 2 Impervious*0.19 ac
Access Tract 0.12 ac
Frontage Impervious 0.01 ac
LID Credit - Pervious Pavers**(0.06)ac
Total Impervious 0.48 ac
Lawn
Lot 1 Pervious 0.18 ac
Lot 2 Pervious 0.16 ac
Access Tract 0.04 ac
Dedicated ROW 0.01 ac
LID Credit - Pervious Pavers**0.06 ac
Total Lawn (Till - Soil Group C)0.45 ac
TOTAL DEVELOPED CONDTIONS 0.93 ac
*Per City of Renton Municipal Code 4-2-110A, the maximum impervious coverage
for lots zoned in R-6 is 55%.
**Per Table 1.2.9A of the 2017 COR SWDM, model permeable pavement area as
50% impervious, 50% grass.
MITCHELL SHORT PLAT
4.4JOB #20-250
Technical Information Report
Flow Frequency Return Periods for Mitigated. POC #1
Return Period Flow(cfs)
2 year 0.222271
5 year 0.297018
10 year 0.350050
25 year 0.421222
50 year 0.477346
100 year 0.536195
Mitigated – Predeveloped = 0.536195 – 0.446122 = 0.090073 cfs
The 100-year runoff for the targeted basin when modeled using WWHM software and a 15-minute time-step
creates less than 0.15 cfs increase over the predeveloped existing site condition, and this therefore exempts the
site from the stormwater detention requirements per Section 1.2.3.1 of the 2017 COR SWDM.
MITCHELL SHORT PLAT
4.5JOB #20-250
Technical Information Report
INFILTRATION TRENCH SIZING
Below provides the infiltration analysis for Lot 2. Infiltration trenches appear feasible for Lot 2, however, a full
review will be conducted with the single-family building permit application.
Infiltration facility sizing was completed using the design criteria provided in Section C.2.3.3 of the 2017 COR
SWDM. The limited infiltration trenches are sized to treat maximum impervious surface per zoning (55% for R-6
zone per Renton Municipal Code 4-2-110) for Lot 2. Soils in the upper 4 to 6 feet were classified as a loamy sand
according to the USDA Soil Textural Classification included in the Site Development Geotechnical
Recommendations letter prepared by Mud Bay Geotechnical Services LLC dated January 29, 2020. Refer to the
Site Development Geotechnical Recommendations letter is provided in Section 6 of this report.
The gravel filled trenches are designed to reach loamy sand soils at depths of approximately 4 to 6 feet deep
from existing grade at the proposed limited infiltration trench locations. Refer to the Developed Conditions
Exhibit for trench locations included in Section 1 of this report. Per Section C.2.3.3 of the 2017 COR SWDM, 21
feet of a 2-foot wide trench (42 sf) can accommodate 1,000 sf of impervious surface area, thus, a minimum
trench footprint of 346 sf is required to infiltrate 8,228 sf of Lot 2 impervious area. A 5’ x 37’ x 2’ deep limited
infiltration trench and a 5’ x 34’ x 2’ deep limited infiltration trench will be provided at building permits. Below is
a summary of impervious area tributary, required, and provided infiltration trench footprint in accordance to
Section C.2.3.3.
INFILTRATION TRENCH FACILITIES
Lot 2 – Limited Infiltration Trench 1 (West)
Impervious Area Tributary 4,305 sf
Required Trench Footprint 181 sf
Provided Trench Footprint 185 sf
Lot 2 – Limited Infiltration Trench 2 (East)
Impervious Area Tributary 3,923 sf
Required Trench Footprint 165 sf
Provided Trench Footprint 170 sf
Infiltration Summary
Total Required Trench Footprint 346 sf
Total Provided Trench Footprint 355 sf
Total Impervious Area Tributary 0.19 ac
MITCHELL SHORT PLAT
4.6JOB #20-250
Technical Information Report
LOW IMPACT DEVELOPMENT BMPS
Core Requirement #9 of the 2017 COR SWDM requires flow control BMPs to be implemented per the
“Individual lot BMP Requirements” included in Section 1.2.9.2 for all new and replaced impervious surfaces to
the maximum extent feasible or meet the Low Impact Development Requirement. The Small Lot BMP
requirements will be met by evaluating flow control BMPs for the target areas and apply BMPs to the maximum
extent feasible. Each BMP was determined feasible or infeasible as follows.
1.Full Dispersion - The site is bounded by Meadow Ave N to the east and existing single-family residences
to the north, south, and west. As such no flow path is available for full dispersion.
2.Full Infiltration of Roof Runoff – Full infiltration for the site has been determined infeasible based on the
soils encountered by Mud Bay Geotechnical Services LLC. The geotechnical evaluation loamy sands which
is not conducive to full infiltration according to C.2.2. As such full infiltration BMPs will not be utilized for
this project. Refer to the Site Development Geotechnical Recommendations letter
3. prepared by Mud Bay Geotechnical Services LLC dated January 29, 2020 included in Section 6 of this
report.
4.Full Infiltration, Limited Infiltration, Bioretention, or Permeable Pavement – According to Site
Development Geotechnical Recommendations letter prepared by Mud Bay Geotechnical Services LLC, site
soil and groundwater conditions meet the King County Manual Appendix C criteria for limited infiltration
with a soil class of loamy sand. A copy of the Site Development Geotechnical Recommendations letter
prepared by Mud Bay Geotechnical Services LLC dated January 29, 2020 included in Section 6 of this
report. The site is proposing two limited infiltration trenches for Lot 2 sized for maximum impervious
coverage per zone. The remaining portion of impervious surface will utilize permeable pavement in
accordance with Section C.2.7 of the COR SWDM.
5.Basic Dispersion – All proposed onsite target impervious surfaces will be treated with infiltration via
permeable pavement and limited infiltration trenches; therefore, implementation of the basic dispersion
BMP is not provided.
6.Reduced Impervious Surface or Native Growth Retention – All proposed onsite target impervious
surfaces will be treated with infiltration via permeable pavement and limited infiltration trenches;
therefore, implementation of these BMPs is not provided.
7.Post-Amended Soils – Amended Soils in accordance with the Section C.2.13 of the COR SWDM will be
applied to all targeted pervious surfaces.
8.Perforated Pipe Connection – All proposed onsite target impervious surfaces will be treated with
infiltration via permeable pavement and limited infiltration trenches; therefore, implementation of the
perforated pipe connection BMP is not provided.
MITCHELL SHORT PLAT
4.7JOB #20-250
Technical Information Report
WATER QUALITY ANALYSIS AND DESIGN
The site proposes 5,205 sf of targeted new plus replaced pollution generating impervious surface (PGIS) which is
more than the 5,000 sf threshold and is therefore subject to Basic Water Quality requirements per Chapter 1,
Section 1.2.8 of the 2017 COR SWDM.
Permeable pavement is proposed for the road within the onsite access tract. The project proposes to treat
stormwater runoff from proposed 4,734 sf of onsite PGIS area via a 6” sand layer beneath the proposed permeable
pavement. The remaining 405 sf of proposed PGIS is located in the existing ROW and proposed dedicated ROW,
as such, will not utilize permeable pavement. Refer to the Site Development Geotechnical Recommendations letter
prepared by Mud Bay Geotechnical Services LLC provided in Section 6 of this report.
MITCHELL SHORT PLAT
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Conveyance Design
STORM PIPE CONVEYANCE
Majority of onsite runoff will be collected via roof and yard drains and routed within a 6-inch storm system to
onsite limited infiltration trenches. Onsite PGIS will utilize permeable surfacing. An overflow will be provided for
the trenches that will ultimately route overflow runoff to Meadow Ave N. The onsite conveyance system was
designed for the 100-year, 24-hour storm event for simplicity. The precipitation rate for the 100-year, 24-hour
storm event is 3.9 inches. The peak rainfall intensity was determined using Figure 3.2.1.D 100-year 24-hour
Isopluvial from the 2016 KCSWDM. A copy of this figure is included at the end of this section.
The 6-inch conveyance system was sized using the Rational Method and Manning’s Equation. For the rational
method, the peak flow rate was calculated using the characteristic of the areas tributary to the 6-inch
conveyance system.For the purposes of analysis, the conveyance system is assumed to convey the maximum
impervious surface per zoning (55% for R-6 zone per Renton Municipal Code 4-2-110A) for Lot 2 and assumed
that none of the onsite runoff is being infiltrated. Runoff from the access tract, dedicated ROW, and frontage
will not enter the onsite storm system, thus, is excluded from the 6-inch capacity analysis. The peak flow,
tributary to the 6-inch conveyance system, is 0.64-cfs for the 100-year storm event. Please see calculations
below. The capacity for the 6-inch conveyance system was calculated using Manning’s Equation. Using
Manning’s equation, a 6-inch pipe at 2% has capacity to convey 0.93-cfs. Therefore, the 6-inch conveyance
system has adequate capacity to convey the 100-year storm. Please see calculations for the north conveyance
system on the following page.
6-INCH CONVEYANCE SYSTEM:
Type of Land Cover C-Value Area
Lawn 0.25 0.15
Pavements and Roofs 0.90 0.18
Total 0.61 0.33
IR - Peak Rainfall Intensity
Storm Event PR AR BR TC IR
Total
Precipitation Coefficient Coefficient Time of
Concentration
100-year 3.9 2.61 0.63 6.30 3.19
Rational Method
Storm Event C IR A QR
100-year 0.61 3.19 0.33 0.64
MITCHELL SHORT PLAT
5.2JOB #20-250
Technical Information Report
MANNING’S EQUATION:
Q = 1.486/n * A * R2/3 * S1/2
n = roughness coefficient =0.011
A = cross sectional area of pipe = π (D/2)2 = π ((6/12) ft/2)2 =0.196
R = wetted perimeter of pipe
R2/3 = (D/4)2/3 = ((6/12) ft/4)2/3 =0.25
S = slope
S1/2 = (0.02 ft/ft)1/2 =0.141
Q = (1.486/0.011) * 0.196 * 0.25 * 0.141 =0.93 cfs
3.2.1 RATIONAL METHOD
2017 City of Renton Surface Water Design Manual 12/12/2016 3-17
FIGURE 3.2.1.D 100-YEAR 24-HOUR ISOPLUVIALS
SITE
MITCHELL SHORT PLAT
6.1JOB #20-250
Technical Information Report
Special Reports and Studies
A Site Development Geotechnical Recommendations letter prepared by Mud Bay Geotechnical Services, LLC
dated January 29, 2020 is included on the following pages.
Mud Bay Geotechnical Services, LLC• 2724 Langridge Loop NW • Olympia, WA 98502
360-481-9784 • cheathman@mudbaygeotech.com
January 29, 2020 Job:1172-KIN
Page 1
Terry Mitchell 3625 Meadow Ave N, Renton WA 98056 Renton, WA 98056
Subject: 3625 Meadow Ave N
Renton, WA 98056
Site Development Geotechnical Recommendations
Dear Ms. Mitchell,
This report presents the results of our geotechnical investigation and contains geotechnical
recommendations for the project taking place at 3625 Meadow Ave N, Renton WA. This is an
updated report that supersedes the report dated December 29, 2019.
The analyses, conclusions, and recommendations in this report are based on three boring
(designated as BH-1-19, BH-2-19, and BH-3-19) completed specifically for this project,
published geologic information for the site and vicinity, USDA textural analysis of retained
samples, and our experience with similar geologic materials. The conditions observed in the
bore holes are assumed to be representative of the subsurface conditions throughout the
project area. If during construction, subsurface conditions differ from those described in the
explorations, we should be advised immediately so we may reevaluate the recommendations.
Location and Description
The parcel number 3342700480 is located at 3526 Meadow Ave N in Renton, WA. The site
location and vicinity for the property are presented in Figure 1. The scope of the project, as we
understand it, is to develop the site with a new access road covering 0.097 acres of the 0.91-acre
parcel, in addition to construction of a new home on Lot #2. Proposed development can be viewed
on the provided Site Plan, attached to this report as Figure 2. It is anticipated the structure will be
supported on shallow strip footing foundations and shallow pier foundations.
RECEIVED
02/11/2020 jding
PLANNING DIVISION
Mud Bay Geotechnical Services, LLC• 2724 Langridge Loop NW • Olympia, WA 98502
360-481-9784 • cheathman@mudbaygeotech.com
The site currently accommodates one single-family residence, a detached 2-car garage, a small
section of asphalt drive, and a gravel access road. Surface conditions on the parcel consists of
manicured and landscaped lawn, with the entirety of the site having a gentle grade projecting
down-slope to the west and north west. Discussions with the client suggest the site is well
draining, with little to no standing water being present following rain events. Several fruit and small
native trees exist in the current front-yard. A retaining wall ranging in height from 2 to 4 feet spans
the southern boundary of the neighboring parcel and appears to be in good condition.
Site Soils and Geology
As part of this project, we reviewed geologic data from the Washington State Department of
Natural Resources available at the 1:100,000 scale and prepared a site-specific geology map,
attached as Figure 3 to this report. The project vicinity geologic map indicates the project site is
directly underlain by Pleistocene continental glacial drift, and the site vicinity consists generally
of Pleistocene continental glacial till and Quaternary alluvium. Conditions observed at the site
are generally consistent with the mapped geology.
Along with the site geology, soil data was also reviewed and is represented in attached Figure
4, USDA Soil Map. The soil in this area was mapped by the United States Department of
Agriculture, USDA, as Indianola loamy sand, 5 to 15 percent slopes. The USDA describes
Indianola loamy sand as being "somewhat excessively drained" and forming often in sandy
glacial drift deposits. Consistency across field classification, mapped soils, and soil descriptions
all indicate the soil conditions at the site are consistent with the USDA mapping. See the
Subsurface Exploration section below for a detailed soil characterization. It should be noted the
percent slopes associated with these soils is an approximation and does not necessarily reflect
the true surface topography.
Subsurface Exploration
As part of the geotechnical investigation, three shallow hand augured borings were completed.
The borings were completed using a Humboldt Manufacturing model H-4414QC hand auger
with a 4-inch diameter bucket tube sampler. In situ testing was performed at selected depths
using a Humboldt Manufacturing model H-4202A dynamic cone penetrometer to estimate the
density of the soil. The dynamic cone penetrometer uses a 15-lb steel mass falling a height of
20-inches onto an anvil to penetrate a 1.5-inch diameter 45-degree cone tip seated into the
bottom of the hole. The number of blows is recorded to achieve at total of ¾ inches of
penetration into the soil. This recorded blow count is correlated to the Standard Penetration Test
(SPT) field N-value blow count determined in accordance with ASTM D1586, which is the
standard in situ test method for determining relative density of cohesionless soils and the
consistency of cohesive soils. Hand auger samples were removed from the bottom of the hole
after the dynamic cone penetration testing was performed in order to observe the soil material at
the approximate depth the test was performed.
The soil samples were classified visually in the field in general accordance with ASTM D2488,
the Standard Practice for Description and Identification of Soils (Visual-Manual Procedure).
Once transported back to the office, the samples were re-examined, and the field classifications
were modified accordingly. We then selected representative samples for a suite of laboratory
tests. The overall soil-testing program included moisture content analyses, Atterberg limits, and
Mud Bay Geotechnical Services, LLC• 2724 Langridge Loop NW • Olympia, WA 98502
360-481-9784 • cheathman@mudbaygeotech.com
particle-size analyses. The results of the laboratory tests are presented in Appendix B.
Summary logs of the borings are included in Appendix A. Note the soil descriptions and
interfaces shown on the log are interpretive, and actual changes may be gradual. Upon
completion, the holes were backfilled to the original ground surface using excavated material
from the spoil piles.
Soil and Groundwater Conditions
Three hand augured borings (designated BH-1-19, BH-2-19, and BH-3-19), were performed to a
depth of 72 inches, 84 inches, and 72 inches, respectively, below the current ground surface in
order to explore the subsurface conditions at the site location. The approximate locations of the
borings have been included as Figure 5 attached to this report, Site Exploration Map. The
subsurface conditions observed in all three of the borings consisted of very loose to loose,
moist, brown, silty sand (SM) to a depth of 72 to 84 inches. It was noted that groundwater, likely
a result of localized seepage, was present in boring BH-2-19. Boring BH-1-19 and BH-3-19 had
moist soils throughout the entire depth.
Shallow Foundation Support
Shallow strip footings will be used to support the new structure loads. Based on the conditions
observed in the boring, we recommend locating the bottom of the new footings on the native soil
deposits at a minimum depth of approximately 1.5 feet below the existing ground surface.
If the footings are placed on the native material at or below a depth of 1.5 feet, then the
subgrade at that elevation should be cleared and grubbed and the exposed native subgrade
soils should be compacted in place. The subgrade should be inspected for any pockets of loose
material. Loose material should be removed and replaced with a minimum of 6-inches of
crushed surfacing base coarse (CSBC). The CSBC should be placed in layers no greater than
6-inches and compacted to at least 95 percent of the maximum dry density. Prior to placement
of the CSBC, we recommend placing a construction geosynthetic directly on the native
subgrade within the footprint of all strip footings, piers, and slabs-on-grade. The geosynthetic
used should meet the requirements of a construction geotextile for soil separation in accordance
with Section 9-33.1 of the WSDOT Standard Specifications.
Footings bearing on a subgrade prepared as described above can be designed using a
maximum allowable bearing pressure of 1,200 psf. We recommend a minimum footing width of
18 inches be used in the design. The maximum allowable bearing pressure may be increased
by up to one-third for short-term transient loading conditions such as wind and seismic loading.
We anticipate that total settlement will not exceed one inch, and differential settlement along an
equivalent 50-foot length of footing will not exceed half of the total settlement. The settlement is
expected to be elastic and will occur as the footings are loaded.
We recommend footing subgrade preparation be evaluated by Mud Bay Geotechnical Services,
LLC prior to placement of concrete. Foundation subgrade preparation should not be performed
during periods of wet weather. We recommend staging the foundation subgrade excavation,
compaction of native subgrade soils, and placement of CSBC to limit the time the foundation
subgrade is exposed to weather.
Mud Bay Geotechnical Services, LLC• 2724 Langridge Loop NW • Olympia, WA 98502
360-481-9784 • cheathman@mudbaygeotech.com
Lateral Earth Pressures
The portion of the new footings and stem walls below final grade should be designed to resist
lateral earth pressures of the backfill placed behind the walls. For lateral load analysis, we
recommend the geotechnical parameters in Table 1 be used for lateral design and analysis.
Table 1: Lateral Earth Pressure Parameters
Parameter Design Value
Backfill Unit Weight (γ) 135 pcf
Wall Backfill Soil Friction Angle (φf) 37°
Coefficient of Sliding (tan φf) 0.55
Active Earth Pressure (Ka) 0.23 (EFP 31.1 psf)
At Rest Earth Pressure (K0) 0.40 (EFP 54.0 psf)
Passive Earth Pressure (Kp) 4.02 (EFP 542.7 psf)
The passive earth pressure coefficient and coefficient of sliding presented in Table 1 are
ultimate values and should be reduced by a factor of safety equal to 1.5 for final design. The
lateral earth pressure coefficients provided in Table 1 are based on the use of Gravel Backfill for
Walls. Active earth pressures can be assumed for design, provided that the walls can yield
laterally at least 0.001H (where H is the exposed wall height in feet). If the wall is not capable of
yielding that amount, then at-rest earth pressures should be used.
Seismic loading represented as a rectangular shaped dynamic uniform lateral surcharge equal
to 8H psf should be applied, with the resultant acting at a height of 0.5H, where H is the height
of the wall. This value, which was calculated using the Mononobe-Okabe method, is appropriate
for yielding walls designed in accordance with the 2015 IBC.
Drainage Considerations
We recommend including a perimeter footing drain system, consisting of a 4-inch diameter,
perforated or slotted, rigid plastic pipe placed at the base of the wall footings. The drain should
be embedded in a clean, free-draining sand and gravel meeting the requirements of Section 9-
03.12(4) of the WSDOT Standard Specifications for Gravel Backfill for Drains. The drains should
be sloped slightly to drain to an appropriate discharge area. Appropriate water and weather
proofing measures should be used in order to reduce the potential for leaks through the stem
walls.
Utilities
Utilities may need to be temporarily or permanently relocated as part of the project. The utility
subgrade (base of trench excavation) should be relatively firm prior to placing bedding
materials. Subgrade that is observed to be soft, pumping, or containing abundant organics or
refuse should be sub-excavated to firm subgrade soil or a maximum depth of 2 feet. Sub-
excavated areas should be backfilled with structural fill.
Mud Bay Geotechnical Services, LLC• 2724 Langridge Loop NW • Olympia, WA 98502
360-481-9784 • cheathman@mudbaygeotech.com
Material placed directly below, around, and above utility pipes should consist of Gravel Backfill
for Pipe Zone Bedding as described in Section 9-03.12(3) of the WSDOT Standard
Specifications. The pipe bedding materials should be placed and compacted to a relatively firm
condition in accordance with the manufacturer’s specifications. Bedding and cover should be a
minimum of 6-inches thick.
Earthwork Considerations
Soils placed as fill beyond the limits of foundation subgrade, wall backfill, and pipe zone areas
described previously should be considered structural fill. Structural fill should consist of material
meeting the requirements of Common Borrow as described in Section 9-03.14(3) of the WSDOT
Standard Specifications. Based on the conditions observed in the boring, the onsite material
that will be removed for construction meets the requirements for Common Borrow, provided that
it can be moisture conditioned to achieve proper compaction. The onsite material contains a
fines content great enough that it is considered to be moisture sensitive. This material may be
difficult to compact if exposed to wet weather. Drying excessively wet soil will be easier during
the drier time of the year.
Structural fill should be placed and compacted in lifts no greater than 8 inches when using
relatively large compaction equipment, such as a vibrating compaction equipment attached to
an excavator or a drum roller. If small, hand-operated compaction equipment is used to compact
the structural fill, fill lifts should not exceed 6 inches. Based on the small size of the project and
difficult access, most likely small hand-operated equipment will be used.
Structural fill should be placed and compacted to between 92 and 95 percent of the maximum
dry density. All other fill material should be placed and compacted as described previously. Fill
placed in softscape, landscape, or common areas that can accommodate some settlement
should be compacted to a relatively firm and unyielding condition.
Stormwater infiltration Design
On site stormwater facilities will be used for stormwater treatment and flow control. The soils in
the upper 4 to 6 feet were classified for USDA soil texture in order to estimate the long-term
infiltration rate. Based on the conditions observed in the borings and laboratory testing for soil
gradation, the soils at the site are classified as a sandy loam to loam soil. We recommend
assuming a long-term infiltration rate of 1.0 inches per hour.
Erosion Control
Erosion control should be implemented during construction with the use of silt fences and
construction fencing around the perimeter of the work area. Jute, coir, or turf reinforcement mat
should be placed on the surface of all exposed ground surfaces with slopes greater than 15
percent, pinned a minimum of 30 inches below the surface. The erosion condition of slopes should
be monitored periodically during construction for any signs of surface erosion or degradation. If
significant erosion is observed, then it should be mitigated as soon as possible. To reduce the
potential for long term erosion from occurring, it is recommended the surface all bare ground are
vegetated following construction with a combination of native plants and hydroseeding.
Mud Bay Geotechnical Services, LLC• 2724 Langridge Loop NW • Olympia, WA 98502
360-481-9784 • cheathman@mudbaygeotech.com
Recommended Additional Services
Before construction begins, we recommend a copy of the draft plans and specifications
prepared for the project be made available for review so that we can ensure that the
geotechnical recommendations in this report are included in the Contract.
Mud Bay Geotechnical Services, LLC is also available to provide geotechnical engineering and
construction monitoring services throughout the remainder of the design and construction of the
project. The integrity of the geotechnical elements of a project depend on proper site
preparation and construction procedures. In addition, engineering decisions may need to be
made in the field if conditions are encountered that differ from those described in this report.
During the construction phase of the project, we recommend that Mud Bay Geotechnical
Services, LLC be retained to review construction submittals, observe and evaluate subgrade for
footings, structural fill placement and compaction, and provide recommendations for any other
geotechnical considerations that may arise during construction.
Intended Use and Limitations
This report has been prepared to assist the client and their consultants in the engineering
design and construction of the subject project. It should not be used, in part or in whole for other
purposes without contacting Mud Bay Geotechnical Services, LLC for a review of the
applicability of such reuse.
This report should be made available to prospective contractors for their information only and
not as a warranty of ground conditions.
The conclusions and recommendations contained in this report are based on Mud Bay
Geotechnical Services, LLC understanding of the project at the time that the report was written
and on-site conditions that existed at time of the field exploration. If significant changes to the
nature, configuration, or scope of the project occur during the design process, we should be
consulted to determine the impact of such changes on the recommendations and conclusions
presented in this report.
Site exploration and testing describes subsurface conditions only at the sites of subsurface
exploration and at the intervals where samples are collected. These data are interpreted by Mud
Bay Geotechnical Services, LLC rendering an opinion regarding the general subsurface
conditions. Actual subsurface conditions can be discovered only during earthwork and
construction operations. The distribution, continuity, thickness, and characteristics of identified
(and unidentified) subsurface materials may vary considerably from that indicated by the
subsurface data. While nothing can be done to prevent such variability, Mud Bay Geotechnical
Services, LLC is prepared to work with the project team to reduce the impacts of variability on
project design, construction, and performance.
We appreciate the opportunity to serve your geotechnical needs on this project and look forward
to working with you in the future. Please contact us at your earliest convenience if you have any
questions or would like to discuss any of the contents of this report.
Mud Bay Geotechnical Services, LLC• 2724 Langridge Loop NW • Olympia, WA 98502
360-481-9784 • cheathman@mudbaygeotech.com
Sincerely,
Chris Heathman, P.E.
Mud Bay Geotechnical Services, LLC
Figure 1: Site Map
3625 Meadow Ave N,
Renton WA, 98056
Site Development Geotechnical Report
JOB #:1172-KIN Date: Nov., 2019
Site Location
Figure 2: Site Plan
3625 Meadow Ave N,
Renton WA, 98056
Site Development Geotechnical Report
JOB #:1172-KIN Date: Nov., 2019
LEGEND
Figure 3: WA DNR Geologic Map
3625 Meadow Ave N,
Renton WA, 98056
Site Development Geotechnical Report
JOB #: 1172-KIN Date: Nov., 2019
Site Location
200 ft
100 m
LEGEND
Site Location
Figure 4: USDA Soils Map
3625 Meadow Ave N,
Renton WA, 98056
Site Development Geotechnical Report
JOB #: 1172-KIN Date: Nov., 2019
BH-1-19 BH-2-19
Site Location
Figure 5: Site Exploration Map
3625 Meadow Ave N,
Renton WA, 98056
Site Development Geotechnical Report
JOB #:1172-KIN Date: Nov., 2019
Sample Location
BH-3-19
APPENDIX A – FINAL BORING LOGS
Completed: Hammer Type:
Backfilled: Hammer Weight: Hammer Drop:
Groundwater Depth: Total Depth of Boring:
Lithology
Very loose, moist, brown, silty sand (SM)
Very loose, moist, brown, silty sand (SM)
Loose, moist, brown, silty sand (SM)
Loose, moist, brown, silty sand (SM)
Standard Penetration Slit Spoon Sampler (SPT)
Blows/3/4"Density
0-4 Very Loose
5-10 Loose
11-24 Medium Dense
25-50 Dense
>50 Vey Dense
Project: Client: Boring No. 1 of 3:
Site Development Terry Mitchell BH-1-19
Project Number:Drilling Contractor:Drill Rig Type:
1172-KIN n/a Hand Auger
Address:DateStarted: Bit Type: Diameter:
3625 Meadow Ave N, Renton
WA 98056
11/6/2019 n/a 4 inches
Fluid:
11/6/2019 Steel n/a
Logged By:
Logan Krehbiel 11/6/2019 15lbs 20 inches
Drill Crew: Elevation:
Samantha Denham none Existing Surface 72"DepthSample TypeSample NumberBlow Counts (blows/3/4")Graphic LogDry Density (pcf)Moisture Content (%)Additional TestSoil Group Name: modifier, color, moisture, density/consistency, grain size, other
descriptors
Rock Description: modifierm color, hardness/degree of concentration, bedding and
joint characteristics, solutions, void conditions.
Bore Log Symbols Soil Density Modifiers
Gravel, Sand, Non-Plastic Silt Elastic Silts and Clays
California Sampler Blows/3/4" Consistency
Shelby Tube 0-1 Very Soft
CPP Sampler 2-4 Soft
StabIlized Ground water 5-8 Medium Stiff
31-60 Hard
31-61 Very Hard
Groundwater At time of Drilling 9-15 Stiff
Bulk/ Bag Sample 16-30 Very Stiff
18"S-1 1
36"S-2 3
54"S-3 6
72"S-4 6
Completed: Hammer Type:
Backfilled: Hammer Weight: Hammer Drop:
Groundwater Depth: Total Depth of Boring:
Lithology
Very loose, moist, brown, silty sand (SM)
Very loose, moist, brown, silty sand (SM)
Loose, moist, brown, silty sand (SM)
Sharp increase in moisture content @ 68".
Very loose, moist, brown, silty sand (SM)
Standard Penetration Slit Spoon Sampler (SPT)
Blows/3/4"Density
0-4 Very Loose
5-10 Loose
11-24 Medium Dense
25-50 Dense
>50 Vey Dense
Project: Client: Boring No. 2 of 3:
Site Development Terry Mitchell BH-2-19
Project Number:Drilling Contractor:Drill Rig Type:
1172-KIN n/a Hand Auger
Address:DateStarted: Bit Type: Diameter:
3625 Meadow Ave N, Renton
WA 98056
11/6/2019 n/a 4 inches
Fluid:
11/6/2019 Steel n/a
Logged By:
Logan Krehbiel 11/6/2019 15lbs 20 inches
Drill Crew: Elevation:
Samantha Denham none Existing Surface 84"DepthSample TypeSample NumberBlow Counts (blows/3/4")Graphic LogDry Density (pcf)Moisture Content (%)Additional TestSoil Group Name: modifier, color, moisture, density/consistency, grain size, other
descriptors
Rock Description: modifierm color, hardness/degree of concentration, bedding and
joint characteristics, solutions, void conditions.
Bore Log Symbols Soil Density Modifiers
Gravel, Sand, Non-Plastic Silt Elastic Silts and Clays
California Sampler Blows/3/4" Consistency
Shelby Tube 0-1 Very Soft
CPP Sampler 2-4 Soft
StabIlized Ground water 5-8 Medium Stiff
31-60 Hard
31-61 Very Hard
Groundwater At time of Drilling 9-15 Stiff
Bulk/ Bag Sample 16-30 Very Stiff
18"S-1 1
36"S-2 6
54"S-3 5
72"S-4 4
Completed: Hammer Type:
Backfilled: Hammer Weight: Hammer Drop:
Groundwater Depth: Total Depth of Boring:
Lithology
Very loose, moist, brown, silty sand (SM)
Very loose, moist, brown, silty sand (SM)
Loose, moist, brown, silty sand (SM)
Loose, moist, brown, silty sand (SM)
Standard Penetration Slit Spoon Sampler (SPT)
Blows/3/4"Density
0-4 Very Loose
5-10 Loose
11-24 Medium Dense
25-50 Dense
>50 Vey Dense
Project: Client: Boring No. 3 of 3:
Site Development Terry Mitchell BH-3-19
Project Number:Drilling Contractor:Drill Rig Type:
1172-KIN n/a Hand Auger
Address:DateStarted: Bit Type: Diameter:
3625 Meadow Ave N, Renton
WA 98056
11/6/2019 n/a 4 inches
Fluid:
11/6/2019 Steel n/a
Logged By:
Logan Krehbiel 11/6/2019 15lbs 20 inches
Drill Crew: Elevation:
Samantha Denham none Existing Surface 72"DepthSample TypeSample NumberBlow Counts (blows/3/4")Graphic LogDry Density (pcf)Moisture Content (%)Additional TestSoil Group Name: modifier, color, moisture, density/consistency, grain size, other
descriptors
Rock Description: modifierm color, hardness/degree of concentration, bedding and
joint characteristics, solutions, void conditions.
Bore Log Symbols Soil Density Modifiers
Gravel, Sand, Non-Plastic Silt Elastic Silts and Clays
California Sampler Blows/3/4" Consistency
Shelby Tube 0-1 Very Soft
CPP Sampler 2-4 Soft
StabIlized Ground water 5-8 Medium Stiff
31-60 Hard
31-61 Very Hard
Groundwater At time of Drilling 9-15 Stiff
Bulk/ Bag Sample 16-30 Very Stiff
18"S-1 1
36"S-2 3
54"S-3 5
72"S-4 6
APPENDIX B – LABORATORY TEST RESULTS
Date Revised:Date Sampled:
Test(s) Performed:Test(s) Performed:
X
X
X
Respectfully Submitted,
NW Region Laboratory Manager
Atterberg Limits
Asphalt Extraction/Gradation
Moisture Content
Specific Gravity, Coarse
Specific Gravity, Fine
Hydrometer Analysis
Proctor
Sand Equivalent
Fracture Count
See Report
WSDOT Degradation
Bulk Density & Voids
Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980
Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974
Visit our website: www.mtc-inc.net
Meghan Blodgett-Carrillo
If you have any questions concerning the test results, the procedures used, or if we can be of any further assistance please call on us at the
number below.
Rice Density
Loamy Sand
Non-plastic
Materials Testing & Consulting, Inc.
Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting
Test Results
Olympia, WA 98502
Chris Heathman
December 10, 2019
19S056-07
B19-1174
Project #:
1172 - KINAddress:
As requested MTC, Inc. has performed the following test(s) on the sample referenced above. The testing was performed in accordance with
current applicable AASHTO or ASTM standards as indicated below. The results obtained in our laboratory were as follows below or on the
attached pages:
Test Results
Client:
Sample #:
Date:
Project:
Mud Bay Geotechnical Services, LLC.
2724 Langridge Loop NW
Attn:
Sulfate SoundnessSieve Analysis
Not Reported
Project:Date Received:4-Dec-19Project #:Sampled By:Client
Client:Date Tested:5-Dec-19
Source:Tested By:A. Eifrig
Sample#:B19-1174
D(5) =0.010 mm % Gravel =1.0%Coeff. of Curvature, CC =1.31SpecificationsD(10) =0.020 mm % Sand =60.5%Coeff. of Uniformity, CU =6.87 No Specs D(15) =0.029 mm % Silt & Clay =38.4%Fineness Modulus =0.74Sample Meets Specs ?N/A D(30) =0.059 mm Liquid Limit =0.0%Plastic Limit =0.0%D(50) =0.107 mm Plasticity Index =0.0%Moisture %, as sampled =n/a
D(60) =0.134 mm Sand Equivalent =n/a Req'd Sand Equivalent = D(90) =0.482 mm Fracture %, 1 Face =n/a Req'd Fracture %, 1 Face =
Dust Ratio =3/7 Fracture %, 2+ Faces =n/a Req'd Fracture %, 2+ Faces =
Actual InterpolatedCumulativeCumulative
Sieve Size Percent Percent Specs SpecsUSMetricPassingPassingMaxMin12.00"300.00 100%100.0%0.0%10.00"250.00 100%100.0%0.0%8.00"200.00 100%100.0%0.0%
6.00"150.00 100%100.0%0.0%
4.00"100.00 100%100.0%0.0%3.00"75.00 100%100.0%0.0%2.50"63.00 100%100.0%0.0%2.00"50.00 100%100%100.0%0.0%
1.75"45.00 100%100.0%0.0%
1.50"37.50 100%100.0%0.0%1.25"31.50 100%100.0%0.0%1.00"25.00 100%100%100.0%0.0%3/4"19.00 100%100%100.0%0.0%
5/8"16.00 100%100.0%0.0%
1/2"12.50 100%100%100.0%0.0%3/8"9.50 100%100%100.0%0.0%1/4"6.30 99%100.0%0.0%#4 4.75 99%99%100.0%0.0%
#8 2.36 99%100.0%0.0%
#10 2.00 98%98%100.0%0.0%#16 1.18 94%100.0%0.0%#20 0.850 92%100.0%0.0%#30 0.600 91%100.0%0.0%
#40 0.425 90%90%100.0%0.0%
#50 0.300 79%100.0%0.0%#60 0.250 75%100.0%0.0%#80 0.180 68%100.0%0.0%#100 0.150 66%66%100.0%0.0%
#140 0.106 50%100.0%0.0%
#170 0.090 44%100.0%0.0%#200 0.075 38.4%38.4%100.0%0.0%
Copyright Spears Engineering & Technical Services PS, 1996-98
Comments:
Reviewed by:
Meghan Blodgett-Carrillo
Materials Testing & Consulting, Inc.
Visit our website: www.mtc-inc.net
All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval.
Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980
Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974
Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting
Sieve Report
ASTM C-136, ASTM D-6913
19S056-07
Mud Bay Geotechnical Services, LLC.
BH-3-19 S3 @ 54''
ASTM D-2487 Unified Soils Classification System
ASTM D-2216, ASTM D-2419, ASTM D-4318, ASTM D-5821
SM, Silty Sand
brown
Sample Color:
1172 - KIN
8"6"4"2"3"1½"1¼"10"1"¾"5/8"½"3/8"¼"#4#8#10#16#20#30#40#50#60#80#100#140#170#2000%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
0.0%
10.0%
20.0%
30.0%
40.0%
50.0%
60.0%
70.0%
80.0%
90.0%
100.0%
0.0010.0100.1001.00010.000100.000% Passing% PassingParticle Size (mm)
Grain Size Distribution
Sieve Sizes Max Specs Min Specs Sieve Results
Project:1172 - KIN Date Received:4-Dec-19Project #:19S056-07 Sampled By:Client
Client :Mud Bay Geotechnical Services, LLC.Date Tested:5-Dec-19 Sample ColorSource:BH-3-19 S3 @ 54''Tested By:A. EifrigSample#:B19-1174
Assumed Sp Gr :2.70
Sample Weight:50.07 grams
Hydroscopic Moist.:6.31%Sieve Percent
Adj. Sample Wgt :47.10 grams Size Passing
3.0"100%75.000 mm
Hydrometer 2.0"100%50.000 mmReadingCorrectedPercent1.5"100%37.500 mm
Minutes Reading Passing 1.25"100%31.500 mm2714.5%0.0371 mm 1.0"100%25.000 mm
5 6.5 13.5%0.0235 mm 3/4"100%19.000 mm155.5 11.4%0.0137 mm 5/8"100%16.000 mm30510.4%0.0097 mm 1/2"100%12.500 mm
60 4.5 9.3%0.0069 mm 3/8"100%9.500 mm25036.2%0.0034 mm 1/4"99%6.300 mm
1440 2.5 5.2%0.0014 mm #4 99%4.750 mm#10 98%2.000 mm% Gravel:1.0%Liquid Limit:0.0 %#20 92%0.850 mm
% Sand:60.5%Plastic Limit:0.0 %#40 90%0.425 mm% Silt:30.8%Plasticity Index:0.0 %#100 66%0.150 mm
% Clay:7.7%#200 38.4%0.075 mm
Silts 37.8%0.074 mm22.7%0.050 mm
12.7%0.020 mmClays7.7%0.005 mm
5.5%0.002 mm
Colloids 3.7%0.001 mm
Particle Size% Sand:77.0%2.0 - 0.05 mm
% Silt:17.4%0.05 - 0.002 mm
% Clay:5.6%< 0.002 mm
Loamy Sand
Comments:
Reviewed by:
Meghan Blodgett-Carrillo
All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from
or regarding our reports is reserved pending our written approval.
USDA Soil Textural Classification
ASTM C-136
Soils Particle
ASTM D-422, HYDROMETER ANALYSIS
Sieve Analysis
Grain Size Distribution
Visit our website: www.mtc-inc.net
Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980
Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974
Materials Testing & Consulting, Inc.
Geotechnical Engineering • Special Inspection • Materials Testing • Environmental Consulting
USDA Soil Textural Classification
Hydrometer Report
SM, Silty Sand
Diameter
brown
Soils Particle
Diameter
ASTM D 2487 Soils Classification
Project:
Project #:
Client:Sample ColorSource:
Sample #:
#1 #2 #3 #4 #5 #6
Weight of Wet Soils + Pan:
Weight of Dry Soils + Pan:Non-Plastic
Weight of Pan:
Weight of Dry Soils:Liquid Limit @ 25 Blows:N/A
Weight of Moisture:Plastic Limit:N/A
% Moisture:Plasticity Index, IP:N/A
Number of Blows:
#1 #2 #3 #4 #5 #6
Weight of Wet Soils + Pan:
Weight of Dry Soils + Pan:Non-Plastic
Weight of Pan:
Weight of Dry Soils:
Weight of Moisture:
% Moisture:
Copyright Spears Engineering & Technical Services PS, 1996-98
Comments:
Reviewed by:
Meghan Blodgett-Carrillo
Geotechnical Engineering • Special Inspections • Materials Testing • Environmental Consulting
Materials Testing & Consulting, Inc.
Regional Offices: Olympia ~ 360.534.9777 Bellingham ~ 360.647.6111 Silverdale ~ 360.698.6787 Tukwila ~ 206.241.1974
6-Dec-19BH-3-19 S3 @ 54''Mud Bay Geotechnical Services, L A. Eifrig
4-Dec-19
Client
ASTM D4318 - Liquid Limit, Plastic Limit and Plasticity Index of Soils
1172 - KIN Unified Soils Classification System, ASTM D-2487Date Received:
B19-1174
Visit our website: www.mtc-inc.net
Corporate ~ 777 Chrysler Drive • Burlington, WA 98233 • Phone (360) 755-1990 • Fax (360) 755-1980
Liquid Limit Determination
threads. Non-plastic.
Liquid limit cannot be determined as the material displays rapid dilation. Plastic limit cannot be established as the material does not roll down to 1/8"
Sampled By:
Date Tested:Tested By:
Plastic Limit Determination
All results apply only to actual locations and materials tested. As a mutual protection to clients, the public and ourselves, all reports are submitted as the confidential property of clients, and authorization for publication of statements, conclusions or extracts from or regarding our reports is reserved pending our written approval.
19S056-07 SM, Silty Sand
brown
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
10 100% MoistureNumber of Blows, "N"
Liquid Limit
0 %
10 %
20 %
30 %
40 %
50 %
60 %
70 %
0%10%20%30%40%50%60%70%80%90%100%110%Plasticity Index Liquid Limit
Plasticity Chart
MH or OH
ML or OLCL-ML
MITCHELL SHORT PLAT
7.1JOB #20-250
Technical Information Report
Other Permits
No additional permits are required for the subject project.
MITCHELL SHORT PLAT
8.1JOB #20-250
Technical Information Report
TESC Analysis and Design
A CSWPPP is provided under separate cover. The temporary erosion and sedimentation control plan has been
designed to reduce the discharge of sediment-laden runoff from the site. The plan is comprised of temporary
measures (rock entrance, filter fence, straw mulch, etc.) as well as permanent measures (hydroseeding and
landscaping). A TESC plan has been included with the Civil Construction plans, submitted under separate cover.
The following BMPs will be applied to prevent erosion and trap sediments within the project site and are shown
on sheet TD-01 of Civil Construction plans:
·Clearing Limits –Prior to any site clearing or grading, the clearing limits are to be marked in the field.
The trees to remain will have tree protection measures installed per City of Kirkland detail on sheet TD-
01 of CIVIL CONSTRUCTION plans.
·Cover Measures – Temporary and permanent cover measures shall be provided to protect all disturbed
areas. Cover measures include the use of surface roughening, mulch, erosion control nets and blankets,
plastic covering, seeding, and sodding. See sheet TD-01 of Civil Construction plans.
·Perimeter Protection – Perimeter protection to filter sediment from sheetwash shall be located
downslope of all disturbed areas and shall be installed prior to upslope grading. The silt fence will be
installed along the boundary pf the site to retain all sediment on site. Additionally, storm drain inlet
protection measures will be applied to all catch basins within the vicinity. See sheet TP-01 of Civil
Construction plans for more details.
·Traffic Area Stabilization –A stabilized construction entrance shall be installed as the first step in
clearing and grading. The construction entrance is to be installed per City of Kirkland Standard Plan No.
CK-E.01 at the location shown on sheet TD-01 of Civil Construction plans.
·Sediment Retention –Perimeter protection to filter sediment from sheetwash shall be located
downslope of all disturbed areas and shall be installed prior to upslope grading. The silt fence will be
installed along the boundary of the site to retain all sediment on site. Additionally, storm drain inlet
protection measures will be applied to all catch basins within the project vicinity. See sheet TD-01 of
Civil Construction plans for more details.
·Surface Water Collection – Due to limited area of disturbance, surface water collection is not required
beyond the implementation of silt fencing and catch basin inserts. Runoff from the frontage will enter
the existing storm drainage system with storm drain inlet protection measures installed. See sheet TP-01
of Civil Construction plans for more details.
·Dewatering Control – Any runoff generated by dewatering shall be treated by releasing the water to a
well vegetated, gently sloping area. See notes on sheet TD-01 of Civil Construction.
MITCHELL SHORT PLAT
8.2JOB #20-250
Technical Information Report
·Dust Control –The use of vegetation, mulching, watering, vacuuming and installation of stabilized
surfaces are several techniques that may be implemented to reduce the amount of sediment susceptible
to air transport. See notes on sheet TD-01 of Civil Construction plans.
·Flow Control–All drainage will remain in a sheet flow condition during construction. This requirement
is, therefore, not applicable.
·Control of Pollutants – Pollutants shall be controlled per TESC notes shown on sheet TD-01 of Civil
Construction plans.
·Protect Existing and Proposed Flow Control BMPs –Protection measures shall be applied/installed and
maintained so as to prevent adverse impacts to existing flow control BMPs and areas of proposed flow
control BMPs for the project in accordance with Appendix D of the Renton Surface Water Design
Manual.
·Maintain BMPs: All temporary and permanent Erosion and Sediment Control (ESC) BMPs shall be
maintained and repaired as needed to ensure continued performance of their intended function. Prior
to final construction approval, the project site shall be stabilized to prevent sediment-laden water from
leaving the site after project completion. All disturbed areas shall be vegetated or otherwise
permanently stabilized. See sheet TD-01 of Civil Construction plans for more detail.
·Manage the Project: The project will be managed to minimize the amount of sediment exposure during
the wet season and inspected/monitored as necessary. As site work progresses, ESC BMPs will be
implemented to address changing site conditions and minimize the amount of sediment laden runoff
from leaving the site
MITCHELL SHORT PLAT
9.1JOB #20-250
Technical Information Report
Bond Quantities, Facilities Summary, and Declaration of
Covenant
A City of Renton Bond Quantity Worksheet is included on the following pages.
Proposed infiltration trenches within Lot 2 will be provided at building permit phase. A declaration of covenant
for the privately maintained infiltration trenches will be provided at the building permit submittal.
Planning Division |1055 South Grady Way – 6 th Floor | Renton, WA 98057 (425) 430-7200
•
•
Section I: Project Information
•
•
•
Section II: Bond Quantities Worksheets
•
•Section II.a EROSION CONTROL (Stabilization/Erosion Sediment Control (ESC))
•Section II.b TRANSPORTATION (Street and Site Improvements)
•Section II.c DRAINAGE (Drainage and Stormwater Facilities):
•Section II.d WATER -ONLY APPLICABLE IF WATER SERVICE IS PROVIDED BY CITY OF RENTON
•Section II.e SANITARY SEWER -ONLY APPLICABLE IF SEWER SERVICE IS PROVIDED BY CITY OF RENTON
•
•
•
•
•
•
Section III. Bond Worksheet
•
BOND QUANTITY WORKSHEET INSTRUCTIONS
This worksheet is intended to be a "working" copy of the bond quantity worksheet, which will be used throughout all phases of the project, from initial
submittal to project close-out approval.
Submit this workbook, in its entirety, as follows:
The following forms are to be completed by the engineer/developer/applicant as applicable to the project:
The Bond Worksheet form will auto-calculate and auto-populate from the information provided in Section I and Section II.
This section includes all pertinent information for the project
Section II contains a separate spreadsheet TAB for each of the following specialties:
(1) electronic copy (.xlsx format) and (1) hard copy of the entire workbook for civil construction permit submittal. Hard copies are to be included as part
of the Technical Information Report (TIR).
(1) electronic copy (.xlsx format) and (1) hard copy of the entire workbook for final close-out submittal.
This section must be completed in its entirety
Information from this section auto-populates to all other relevant areas of the workbook
This section calculates the required Permit Bond for construction permit issuance as well as the required Maintenance Bond for project close-out
submittals to release the permit bond on a project.
All unit prices include labor, equipment, materials, overhead and profit.
Complete the 'Quantity' columns for each of the appropriate section(s). Include existing Right-of-Way (ROW), Future Public Improvements and Private
Improvements.
The 'Quantity Remaining' column is only to be used when a project is under construction. The City allows one (1) bond reduction during the life of the
project with the exception of the maintenance period reduction.
Excel will auto-calculate and auto-populate the relevant fields and subtotals throughout the document. Only the 'Quantity' columns should need
completing.
Additional items not included in the lists can be added under the "write-in" sections. Provide a complete description, cost estimate and unit of measure
for each write-in item.
Note: Private improvements, with the exception of stormwater facilities, are not included in the bond amount calculation, but must be entered on the
form. Stormwater facilities (public and private) are required to be included in the bond amount.
Page 1 of 14
Ref 8-H Bond Quantity Worksheet INSTRUCTIONS
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 3/11/2021
Planning Division |1055 South Grady Way – 6 th Floor | Renton, WA 98057 (425) 430-7200
Date Prepared:
Name:
PE Registration No:
Firm Name:
Firm Address:
Phone No.
Email Address:
Project Name:Project Owner:
CED Plan # (LUA):Phone:
CED Permit # (U):Address:
Site Address:
Street Intersection:Addt'l Project Owner:
Parcel #(s):Phone:
Address:
Clearing and grading greater than or equal to 5,000 board feet of timber?
Yes/No:NO Water Service Provided by:
If Yes, Provide Forest Practice Permit #:Sewer Service Provided by:
Abbreviated Legal
Description:
Lot 98, C.D. Hillmans Lake Washington Garden of Eden Addition to
Seattle No. 2, Less West 250 Feet, Thereof, According to the Plat
Thereof Recorded in Volume 11 of Plats, Page 64, Records of King
County, Washington. Situated in the County of King, State of
Washington.
3625 Meadow Avenue N
19609 145th Ave SE
N 37th St and Meadow Ave N
417101
206-498-1852
3/10/2021
Prepared by:
FOR APPROVALProject Phase 1
lzirotti@thebluelinegroup.com
Lucas Zirotti, EIT
N/A
Blueline
25 Central Way, Suite 400
425-250-7223
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
PROJECT INFORMATION
CITY OF RENTON
CITY OF RENTON
1Select the current project status/phase from the following options:
For Approval - Preliminary Data Enclosed, pending approval from the City;
For Construction - Estimated Data Enclosed, Plans have been approved for contruction by the City;
Project Closeout - Final Costs and Quantities Enclosed for Project Close-out Submittal
Engineer Stamp Required
(all cost estimates must have original wet stamp and signature)
Clearing and Grading Utility Providers
N/A
Project Location and Description Project Owner Information
Mitchell Short Plat
Renton, WA 98056
3342700480
Teresa Mitchell
20-000044
Page 2 of 14
Ref 8-H Bond Quantity Worksheet SECTION I PROJECT INFORMATION
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 3/11/2021
stamp
CED Permit #:417101
Unit
Reference #Price Unit Quantity CostBackfill & compaction-embankment ESC-1 6.50$CYCheck dams, 4" minus rock ESC-2 SWDM 5.4.6.3 80.00$EachCatch Basin Protection ESC-3 35.50$EachCrushed surfacing 1 1/4" minus ESC-4 WSDOT 9-03.9(3)95.00$CYDitchingESC-5 9.00$CYExcavation-bulk ESC-6 2.00$CY
Fence, silt ESC-7 SWDM 5.4.3.1 1.50$LF 271 406.50
Fence, Temporary (NGPE)ESC-8 1.50$LF
Geotextile Fabric ESC-9 2.50$SY
Hay Bale Silt Trap ESC-10 0.50$Each
Hydroseeding ESC-11 SWDM 5.4.2.4 0.80$SY
Interceptor Swale / Dike ESC-12 1.00$LFJute Mesh ESC-13 SWDM 5.4.2.2 3.50$SYLevel Spreader ESC-14 1.75$LFMulch, by hand, straw, 3" deep ESC-15 SWDM 5.4.2.1 2.50$SYMulch, by machine, straw, 2" deep ESC-16 SWDM 5.4.2.1 2.00$SYPiping, temporary, CPP, 6"ESC-17 12.00$LFPiping, temporary, CPP, 8"ESC-18 14.00$LF
Piping, temporary, CPP, 12"ESC-19 18.00$LF
Plastic covering, 6mm thick, sandbagged ESC-20 SWDM 5.4.2.3 4.00$SY
Rip Rap, machine placed; slopes ESC-21 WSDOT 9-13.1(2)45.00$CY
Rock Construction Entrance, 50'x15'x1'ESC-22 SWDM 5.4.4.1 1,800.00$Each
Rock Construction Entrance, 100'x15'x1'ESC-23 SWDM 5.4.4.1 3,200.00$Each 1 3,200.00
Sediment pond riser assembly ESC-24 SWDM 5.4.5.2 2,200.00$Each
Sediment trap, 5' high berm ESC-25 SWDM 5.4.5.1 19.00$LFSed. trap, 5' high, riprapped spillway berm section ESC-26 SWDM 5.4.5.1 70.00$LFSeeding, by hand ESC-27 SWDM 5.4.2.4 1.00$SYSodding, 1" deep, level ground ESC-28 SWDM 5.4.2.5 8.00$SYSodding, 1" deep, sloped ground ESC-29 SWDM 5.4.2.5 10.00$SYTESC Supervisor ESC-30 110.00$HRWater truck, dust control ESC-31 SWDM 5.4.7 140.00$HR
Unit
Reference #Price Unit Quantity Cost
1.50$LF 267 400.50
1.50$LF 330 495.00
EROSION/SEDIMENT SUBTOTAL:4,502.00
SALES TAX @ 10%450.20
EROSION/SEDIMENT TOTAL:4,952.20
(A)
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR EROSION & SEDIMENT CONTROL
Description No.
(A)
Tree Protection Fence
Construction Fence
WRITE-IN-ITEMS
Page 3 of 14
Ref 8-H Bond Quantity Worksheet SECTION II.a EROSION_CONTROL
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 3/11/2021
CED Permit #:417101
Existing Future Public Private
Right-of-Way Improvements Improvements
(D) (E)Description No.Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.CostGENERAL ITEMSBackfill & Compaction- embankment GI-1 6.00$CY
Backfill & Compaction- trench GI-2 9.00$CY
Clear/Remove Brush, by hand (SY)GI-3 1.00$SY
Bollards - fixed GI-4 240.74$Each
Bollards - removable GI-5 452.34$Each
Clearing/Grubbing/Tree Removal GI-6 10,000.00$Acre 0.49 4,900.00
Excavation - bulk GI-7 2.00$CY
Excavation - Trench GI-8 5.00$CY
Fencing, cedar, 6' high GI-9 20.00$LF
Fencing, chain link, 4'GI-10 38.31$LF
Fencing, chain link, vinyl coated, 6' high GI-11 20.00$LF
Fencing, chain link, gate, vinyl coated, 20'GI-12 1,400.00$Each
Fill & compact - common barrow GI-13 25.00$CY
Fill & compact - gravel base GI-14 27.00$CY
Fill & compact - screened topsoil GI-15 39.00$CY
Gabion, 12" deep, stone filled mesh GI-16 65.00$SY
Gabion, 18" deep, stone filled mesh GI-17 90.00$SY
Gabion, 36" deep, stone filled mesh GI-18 150.00$SY
Grading, fine, by hand GI-19 2.50$SY
Grading, fine, with grader GI-20 2.00$SY
Monuments, 3' Long GI-21 250.00$Each
Sensitive Areas Sign GI-22 7.00$Each
Sodding, 1" deep, sloped ground GI-23 8.00$SY
Surveying, line & grade GI-24 850.00$Day
Surveying, lot location/lines GI-25 1,800.00$Acre
Topsoil Type A (imported)GI-26 28.50$CY
Traffic control crew ( 2 flaggers )GI-27 120.00$HR
Trail, 4" chipped wood GI-28 8.00$SY
Trail, 4" crushed cinder GI-29 9.00$SY
Trail, 4" top course GI-30 12.00$SY
Conduit, 2"GI-31 5.00$LF
Wall, retaining, concrete GI-32 55.00$SF 210 11,550.00
Wall, rockery GI-33 15.00$SF
SUBTOTAL THIS PAGE:16,450.00
(B)(C)(D)(E)
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR STREET AND SITE IMPROVEMENTS
Quantity Remaining
(Bond Reduction)
(B)(C)
Page 4 of 14
Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 3/11/2021
CED Permit #:417101
Existing Future Public Private
Right-of-Way Improvements Improvements
(D) (E)Description No.Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR STREET AND SITE IMPROVEMENTS
Quantity Remaining
(Bond Reduction)
(B)(C)
ROAD IMPROVEMENT/PAVEMENT/SURFACINGAC Grinding, 4' wide machine < 1000sy RI-1 30.00$SY
AC Grinding, 4' wide machine 1000-2000sy RI-2 16.00$SY
AC Grinding, 4' wide machine > 2000sy RI-3 10.00$SY
AC Removal/Disposal RI-4 35.00$SY
Barricade, Type III ( Permanent )RI-5 56.00$LF
Guard Rail RI-6 30.00$LF
Curb & Gutter, rolled RI-7 17.00$LF
Curb & Gutter, vertical RI-8 12.50$LF
Curb and Gutter, demolition and disposal RI-9 18.00$LF
Curb, extruded asphalt RI-10 5.50$LF
Curb, extruded concrete RI-11 7.00$LF
Sawcut, asphalt, 3" depth RI-12 1.85$LF 58 107.30
Sawcut, concrete, per 1" depth RI-13 3.00$LF
Sealant, asphalt RI-14 2.00$LF
Shoulder, gravel, 4" thick RI-15 15.00$SY
Sidewalk, 4" thick RI-16 38.00$SY
Sidewalk, 4" thick, demolition and disposal RI-17 32.00$SY
Sidewalk, 5" thick RI-18 41.00$SY
Sidewalk, 5" thick, demolition and disposal RI-19 40.00$SY
Sign, Handicap RI-20 85.00$Each
Striping, per stall RI-21 7.00$Each
Striping, thermoplastic, ( for crosswalk )RI-22 3.00$SF
Striping, 4" reflectorized line RI-23 0.50$LF
Additional 2.5" Crushed Surfacing RI-24 3.60$SY
HMA 1/2" Overlay 1.5"RI-25 14.00$SY
HMA 1/2" Overlay 2"RI-26 18.00$SY
HMA Road, 2", 4" rock, First 2500 SY RI-27 28.00$SY 50 1,400.00 14 392.00
HMA Road, 2", 4" rock, Qty. over 2500SY RI-28 21.00$SY
HMA Road, 4", 6" rock, First 2500 SY RI-29 45.00$SY
HMA Road, 4", 6" rock, Qty. over 2500 SY RI-30 37.00$SY
HMA Road, 4", 4.5" ATB RI-31 38.00$SY
Gravel Road, 4" rock, First 2500 SY RI-32 15.00$SY
Gravel Road, 4" rock, Qty. over 2500 SY RI-33 10.00$SY
Thickened Edge RI-34 8.60$LF
SUBTOTAL THIS PAGE:1,507.30 392.00
(B)(C)(D)(E)
Page 5 of 14
Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 3/11/2021
CED Permit #:417101
Existing Future Public Private
Right-of-Way Improvements Improvements
(D) (E)Description No.Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR STREET AND SITE IMPROVEMENTS
Quantity Remaining
(Bond Reduction)
(B)(C)
PARKING LOT SURFACING No.2" AC, 2" top course rock & 4" borrow PL-1 21.00$SY
2" AC, 1.5" top course & 2.5" base course PL-2 28.00$SY
4" select borrow PL-3 5.00$SY
1.5" top course rock & 2.5" base course PL-4 14.00$SY
SUBTOTAL PARKING LOT SURFACING:
(B)(C)(D)(E)
LANDSCAPING & VEGETATION No.Street Trees LA-1
Median Landscaping LA-2
Right-of-Way Landscaping LA-3
Wetland Landscaping LA-4
SUBTOTAL LANDSCAPING & VEGETATION:
(B)(C)(D)(E)
TRAFFIC & LIGHTING No.Signs TR-1
Street Light System ( # of Poles)TR-2
Traffic Signal TR-3
Traffic Signal Modification TR-4
SUBTOTAL TRAFFIC & LIGHTING:
(B)(C)(D)(E)
WRITE-IN-ITEMS
SUBTOTAL WRITE-IN ITEMS:
STREET AND SITE IMPROVEMENTS SUBTOTAL:1,507.30 392.00 16,450.00
SALES TAX @ 10%150.73 39.20 1,645.00
STREET AND SITE IMPROVEMENTS TOTAL:1,658.03 431.20 18,095.00
(B)(C)(D)(E)
Page 6 of 14
Ref 8-H Bond Quantity Worksheet SECTION II.b TRANSPORTATION
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 3/11/2021
CED Permit #:417101
Existing Future Public PrivateRight-of-Way Improvements Improvements
(D) (E)Description No.Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
DRAINAGE (CPE = Corrugated Polyethylene 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 26.00$SY
* (CBs include frame and lid)
Beehive D-2 90.00$Each
Through-curb Inlet Framework D-3 400.00$Each
CB Type I D-4 1,500.00$Each
CB Type IL D-5 1,750.00$Each
CB Type II, 48" diameter D-6 2,300.00$Each
for additional depth over 4'D-7 480.00$FT
CB Type II, 54" diameter D-8 2,500.00$Each
for additional depth over 4'D-9 495.00$FT
CB Type II, 60" diameter D-10 2,800.00$Each
for additional depth over 4'D-11 600.00$FT
CB Type II, 72" diameter D-12 6,000.00$Each
for additional depth over 4'D-13 850.00$FT
CB Type II, 96" diameter D-14 14,000.00$Each
for additional depth over 4'D-15 925.00$FT
Trash Rack, 12"D-16 350.00$Each
Trash Rack, 15"D-17 410.00$Each
Trash Rack, 18"D-18 480.00$Each
Trash Rack, 21"D-19 550.00$Each
Cleanout, PVC, 4"D-20 150.00$Each
Cleanout, PVC, 6"D-21 170.00$Each 5 850.00
Cleanout, PVC, 8"D-22 200.00$Each
Culvert, PVC, 4"D-23 10.00$LF
Culvert, PVC, 6"D-24 13.00$LF 19 247.00
Culvert, PVC, 8"D-25 15.00$LF
Culvert, PVC, 12"D-26 23.00$LF
Culvert, PVC, 15"D-27 35.00$LF
Culvert, PVC, 18"D-28 41.00$LF
Culvert, PVC, 24"D-29 56.00$LF
Culvert, PVC, 30"D-30 78.00$LF
Culvert, PVC, 36"D-31 130.00$LF
Culvert, CMP, 8"D-32 19.00$LF
Culvert, CMP, 12"D-33 29.00$LF
SUBTOTAL THIS PAGE:1,097.00
(B)(C)(D)(E)
Quantity Remaining
(Bond Reduction)(B)(C)
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR DRAINAGE AND STORMWATER FACILITIES
Page 7 of 14
Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 3/11/2021
CED Permit #:417101
Existing Future Public PrivateRight-of-Way Improvements Improvements
(D) (E)Description No.Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
Quantity Remaining
(Bond Reduction)(B)(C)
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR DRAINAGE AND STORMWATER FACILITIES
DRAINAGE (Continued)Culvert, CMP, 15"D-34 35.00$LF
Culvert, CMP, 18"D-35 41.00$LF
Culvert, CMP, 24"D-36 56.00$LF
Culvert, CMP, 30"D-37 78.00$LFCulvert, CMP, 36"D-38 130.00$LF
Culvert, CMP, 48"D-39 190.00$LF
Culvert, CMP, 60"D-40 270.00$LF
Culvert, CMP, 72"D-41 350.00$LF
Culvert, Concrete, 8"D-42 42.00$LF
Culvert, Concrete, 12"D-43 48.00$LF
Culvert, Concrete, 15"D-44 78.00$LF
Culvert, Concrete, 18"D-45 48.00$LF
Culvert, Concrete, 24"D-46 78.00$LF
Culvert, Concrete, 30"D-47 125.00$LF
Culvert, Concrete, 36"D-48 150.00$LF
Culvert, Concrete, 42"D-49 175.00$LF
Culvert, Concrete, 48"D-50 205.00$LF
Culvert, CPE Triple Wall, 6"D-51 14.00$LF
Culvert, CPE Triple Wall, 8"D-52 16.00$LF
Culvert, CPE Triple Wall, 12"D-53 24.00$LF
Culvert, CPE Triple Wall, 15"D-54 35.00$LF
Culvert, CPE Triple Wall, 18"D-55 41.00$LF
Culvert, CPE Triple Wall, 24"D-56 56.00$LF
Culvert, CPE Triple Wall, 30"D-57 78.00$LF
Culvert, CPE Triple Wall, 36"D-58 130.00$LF
Culvert, LCPE, 6"D-59 60.00$LF
Culvert, LCPE, 8"D-60 72.00$LF
Culvert, LCPE, 12"D-61 84.00$LF
Culvert, LCPE, 15"D-62 96.00$LF
Culvert, LCPE, 18"D-63 108.00$LF
Culvert, LCPE, 24"D-64 120.00$LF
Culvert, LCPE, 30"D-65 132.00$LF
Culvert, LCPE, 36"D-66 144.00$LF
Culvert, LCPE, 48"D-67 156.00$LF
Culvert, LCPE, 54"D-68 168.00$LF
SUBTOTAL THIS PAGE:
(B)(C)(D)(E)
Page 8 of 14
Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 3/11/2021
CED Permit #:417101
Existing Future Public PrivateRight-of-Way Improvements Improvements
(D) (E)Description No.Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
Quantity Remaining
(Bond Reduction)(B)(C)
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR DRAINAGE AND STORMWATER FACILITIES
DRAINAGE (Continued)Culvert, LCPE, 60"D-69 180.00$LF
Culvert, LCPE, 72"D-70 192.00$LF
Culvert, HDPE, 6"D-71 42.00$LF
Culvert, HDPE, 8"D-72 42.00$LF
Culvert, HDPE, 12"D-73 74.00$LF
Culvert, HDPE, 15"D-74 106.00$LF
Culvert, HDPE, 18"D-75 138.00$LF
Culvert, HDPE, 24"D-76 221.00$LF
Culvert, HDPE, 30"D-77 276.00$LF
Culvert, HDPE, 36"D-78 331.00$LF
Culvert, HDPE, 48"D-79 386.00$LF
Culvert, HDPE, 54"D-80 441.00$LF
Culvert, HDPE, 60"D-81 496.00$LF
Culvert, HDPE, 72"D-82 551.00$LF
Pipe, Polypropylene, 6"D-83 84.00$LF
Pipe, Polypropylene, 8"D-84 89.00$LF
Pipe, Polypropylene, 12"D-85 95.00$LF
Pipe, Polypropylene, 15"D-86 100.00$LF
Pipe, Polypropylene, 18"D-87 106.00$LF
Pipe, Polypropylene, 24"D-88 111.00$LF
Pipe, Polypropylene, 30"D-89 119.00$LF
Pipe, Polypropylene, 36"D-90 154.00$LF
Pipe, Polypropylene, 48"D-91 226.00$LF
Pipe, Polypropylene, 54"D-92 332.00$LF
Pipe, Polypropylene, 60"D-93 439.00$LF
Pipe, Polypropylene, 72"D-94 545.00$LF
Culvert, DI, 6"D-95 61.00$LF 151 9,211.00
Culvert, DI, 8"D-96 84.00$LF
Culvert, DI, 12"D-97 106.00$LF
Culvert, DI, 15"D-98 129.00$LF
Culvert, DI, 18"D-99 152.00$LF
Culvert, DI, 24"D-100 175.00$LF
Culvert, DI, 30"D-101 198.00$LF
Culvert, DI, 36"D-102 220.00$LF
Culvert, DI, 48"D-103 243.00$LF
Culvert, DI, 54"D-104 266.00$LF
Culvert, DI, 60"D-105 289.00$LF
Culvert, DI, 72"D-106 311.00$LF
SUBTOTAL THIS PAGE:9,211.00
(B)(C)(D)(E)
Page 9 of 14
Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 3/11/2021
CED Permit #:417101
Existing Future Public PrivateRight-of-Way Improvements Improvements
(D) (E)Description No.Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
Quantity Remaining
(Bond Reduction)(B)(C)
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR DRAINAGE AND STORMWATER FACILITIES
Specialty Drainage ItemsDitching SD-1 9.50$CY
Flow Dispersal Trench (1,436 base+)SD-3 28.00$LF
French Drain (3' depth)SD-4 26.00$LF
Geotextile, laid in trench, polypropylene SD-5 3.00$SY
Mid-tank Access Riser, 48" dia, 6' deep SD-6 2,000.00$Each
Pond Overflow Spillway SD-7 16.00$SY
Restrictor/Oil Separator, 12"SD-8 1,150.00$Each
Restrictor/Oil Separator, 15"SD-9 1,350.00$Each
Restrictor/Oil Separator, 18"SD-10 1,700.00$Each
Riprap, placed SD-11 42.00$CY
Tank End Reducer (36" diameter)SD-12 1,200.00$Each
Infiltration pond testing SD-13 125.00$HR
Permeable Pavement SD-14 120.00$SY 470 56,400.00
Permeable Concrete Sidewalk SD-15
Culvert, Box __ ft x __ ft SD-16
SUBTOTAL SPECIALTY DRAINAGE ITEMS:56,400.00
(B)(C)(D)(E)STORMWATER FACILITIES (Include Flow Control and Water Quality Facility Summary Sheet and Sketch)
Detention Pond SF-1 Each
Detention Tank SF-2 Each
Detention Vault SF-3 Each
Infiltration Pond SF-4 Each
Infiltration Tank SF-5 Each
Infiltration Vault SF-6 Each
Infiltration Trenches SF-7 Each
Basic Biofiltration Swale SF-8 Each
Wet Biofiltration Swale SF-9 Each
Wetpond SF-10 Each
Wetvault SF-11 Each
Sand Filter SF-12 Each
Sand Filter Vault SF-13 Each
Linear Sand Filter SF-14 Each
Proprietary Facility SF-15 Each
Bioretention Facility SF-16 Each
SUBTOTAL STORMWATER FACILITIES:
(B)(C)(D)(E)
Page 10 of 14
Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 3/11/2021
CED Permit #:417101
Existing Future Public PrivateRight-of-Way Improvements Improvements
(D) (E)Description No.Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
Quantity Remaining
(Bond Reduction)(B)(C)
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR DRAINAGE AND STORMWATER FACILITIES
WRITE-IN-ITEMS (INCLUDE ON-SITE BMPs)WI-1
WI-2
WI-3
WI-4
WI-5
WI-6
WI-7
WI-8
WI-9
WI-10
WI-11
WI-12
WI-13
WI-14
WI-15
SUBTOTAL WRITE-IN ITEMS:
DRAINAGE AND STORMWATER FACILITIES SUBTOTAL:66,708.00
SALES TAX @ 10%6,670.80
DRAINAGE AND STORMWATER FACILITIES TOTAL:73,378.80
(B)(C)(D)(E)
Page 11 of 14
Ref 8-H Bond Quantity Worksheet SECTION II.c DRAINAGE
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 3/11/2021
CED Permit #:417101
Existing Future Public Private
Right-of-Way Improvements Improvements
(D) (E)Description No.Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
Connection to Existing Watermain W-1 2,000.00$Each 2 4,000.00
Ductile Iron Watermain, CL 52, 4 Inch Diameter W-2 50.00$LF
Ductile Iron Watermain, CL 52, 6 Inch Diameter W-3 56.00$LF
Ductile Iron Watermain, CL 52, 8 Inch Diameter W-4 60.00$LF
Ductile Iron Watermain, CL 52, 10 Inch Diameter W-5 70.00$LF
Ductile Iron Watermain, CL 52, 12 Inch Diameter W-6 80.00$LF
Gate Valve, 4 inch Diameter W-7 500.00$Each
Gate Valve, 6 inch Diameter W-8 700.00$Each
Gate Valve, 8 Inch Diameter W-9 800.00$Each
Gate Valve, 10 Inch Diameter W-10 1,000.00$Each
Gate Valve, 12 Inch Diameter W-11 1,200.00$Each
Fire Hydrant Assembly W-12 4,000.00$Each 1 4,000.00
Permanent Blow-Off Assembly W-13 1,800.00$Each
Air-Vac Assembly, 2-Inch Diameter W-14 2,000.00$Each
Air-Vac Assembly, 1-Inch Diameter W-15 1,500.00$Each
Compound Meter Assembly 3-inch Diameter W-16 8,000.00$Each
Compound Meter Assembly 4-inch Diameter W-17 9,000.00$Each
Compound Meter Assembly 6-inch Diameter W-18 10,000.00$Each
Pressure Reducing Valve Station 8-inch to 10-inch W-19 20,000.00$Each
WATER SUBTOTAL:8,000.00
SALES TAX @ 10%800.00
WATER TOTAL:8,800.00
(B)(C)(D)(E)
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR WATER
Quantity Remaining
(Bond Reduction)
(B)(C)
Page 12 of 14
Ref 8-H Bond Quantity Worksheet SECTION II.d WATER
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 3/11/2021
CED Permit #:417101
Existing Future Public PrivateRight-of-Way Improvements Improvements
(D) (E)Description No.Unit Price Unit Quant.Cost Quant.Cost Quant.Cost Quant.Cost
Clean Outs SS-1 1,000.00$Each 6 6,000.00
Grease Interceptor, 500 gallon SS-2 8,000.00$Each
Grease Interceptor, 1000 gallon SS-3 10,000.00$Each
Grease Interceptor, 1500 gallon SS-4 15,000.00$Each
Side Sewer Pipe, PVC. 4 Inch Diameter SS-5 80.00$LF
Side Sewer Pipe, PVC. 6 Inch Diameter SS-6 95.00$LF 69 6,555.00 462 43,890.00
Sewer Pipe, PVC, 8 inch Diameter SS-7 105.00$LF
Sewer Pipe, PVC, 12 Inch Diameter SS-8 120.00$LF
Sewer Pipe, DI, 8 inch Diameter SS-9 115.00$LF
Sewer Pipe, DI, 12 Inch Diameter SS-10 130.00$LF
Manhole, 48 Inch Diameter SS-11 6,000.00$Each
Manhole, 54 Inch Diameter SS-13 6,500.00$Each
Manhole, 60 Inch Diameter SS-15 7,500.00$Each
Manhole, 72 Inch Diameter SS-17 8,500.00$Each
Manhole, 96 Inch Diameter SS-19 14,000.00$Each
Pipe, C-900, 12 Inch Diameter SS-21 180.00$LF
Outside Drop SS-24 1,500.00$LS
Inside Drop SS-25 1,000.00$LS
Sewer Pipe, PVC, ____ Inch Diameter SS-26Lift Station (Entire System)SS-27 LS
SANITARY SEWER SUBTOTAL:6,555.00 49,890.00
SALES TAX @ 10%655.50 4,989.00
SANITARY SEWER TOTAL:7,210.50 54,879.00
(B)(C)(D)(E)
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
FOR SANITARY SEWER
Quantity Remaining
(Bond Reduction)(B)(C)
Page 13 of 14
Ref 8-H Bond Quantity Worksheet SECTION II.e SANITARY SEWER
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 3/11/2021
Planning Division |1055 South Grady Way – 6th Floor | Renton, WA 98057 (425) 430-7200
Date:
Name:Project Name:
PE Registration No:CED Plan # (LUA):
Firm Name:CED Permit # (U):
Firm Address:Site Address:
Phone No.Parcel #(s):
Email Address:Project Phase:
Site Restoration/Erosion Sediment Control Subtotal (a)
Existing Right-of-Way Improvements Subtotal (b)(b)17,668.53$
Future Public Improvements Subtotal (c)431.20$
Stormwater & Drainage Facilities(Public & Private) Subtotal (d)(d)73,378.80$
(e)
(f)
Site Restoration
Civil Construction Permit
Maintenance Bond 18,295.71$
Bond Reduction 2
Construction Permit Bond Amount 3
Minimum Bond Amount is $10,000.00
1Estimate Only - May involve multiple and variable components, which will be established on an individual basis by Development Engineering.
2 The City of Renton allows one request only for bond reduction prior to the maintenance period. Reduction of not more than 70% of the original bond amount, provided that the remaining 30% will
cover all remaining items to be constructed.
3 Required Bond Amounts are subject to review and modification by Development Engineering.
* Note: The word BOND as used in this document means any financial guarantee acceptable to the City of Renton.
** Note: All prices include labor, equipment, materials, overhead and profit.
EST1
((b) + (c) + (d)) x 20%
-$
MAINTENANCE BOND */**
(after final acceptance of construction)
4,952.20$
17,668.53$
99,881.60$
4,952.20$
-$
73,378.80$
-$
104,833.80$
P
(a) x 100%
SITE IMPROVEMENT BOND QUANTITY WORKSHEET
BOND CALCULATIONS
3/10/2021
Lucas Zirotti, EIT
N/A
Blueline
R
((b x 150%) + (d x 100%))
S
(e) x 150% + (f) x 100%
Bond Reduction: Existing Right-of-Way Improvements (Quantity
Remaining)2
Bond Reduction: Stormwater & Drainage Facilities (Quantity
Remaining)2
T
(P +R - S)
Prepared by:Project Information
CONSTRUCTION BOND AMOUNT */**
(prior to permit issuance)
425-250-7223
lzirotti@thebluelinegroup.com
Mitchell Short Plat
20-000044
3625 Meadow Avenue N
3342700480
FOR APPROVAL
417101
25 Central Way, Suite 400
Page 14 of 14
Ref 8-H Bond Quantity Worksheet SECTION III. BOND WORKSHEET
Unit Prices Updated: 06/14/2016
Version: 04/26/2017
Printed 3/11/2021
MITCHELL SHORT PLAT
10.1
JOB #20-250
Technical Information Report
Operations and Maintenance
Individual owners will be responsible for their tight-lined roof and footing drains and private service drain systems
located within their property limits. Symptoms of failure of this system are yard drains, clean-outs, or catch basins
overtopping. If this happens, the homeowners should remove the yard drain lid or clean-out lid and remove visible
debris. If problems still persist, the homeowner should have the service drain line cleaned.
Operation and Maintenance information from the 2017 COR SWDM included on the following pages is summarized as
follows:
No. 5 – Catch Basins and Manholes (p. A-9)
No. 6 – Conveyance Pipes and Ditches (p. A-11)
No. 11 – Grounds (Landscaping) (p. A-16)
No. 12 – Access Roads (p. A-17)
No. 30 – Permeable Pavement BMP (p. A-41
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
12/12/2016 2017 City of Renton Surface Water Design Manual A-10
NO. 5 – CATCH BASINS AND MANHOLES
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITION WHEN MAINTENANCE
IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Structure Sediment accumulation Sediment exceeds 60% of the depth from the bottom 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 no sediment.
Trash and debris 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 exceeds 1/3 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.
Deposits of garbage exceeding 1 cubic foot in volume. No condition present which would attract or support the breeding of insects or rodents.
Damage to frame and/or top slab 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.
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 in walls or bottom 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 is structurally sound.
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.
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.
Inlet/Outlet Pipe 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.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
2017 City of Renton Surface Water Design Manual 12/12/2016 A-11
NO. 5 – CATCH BASINS AND MANHOLES
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITION WHEN MAINTENANCE
IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Inlet/Outlet Pipe (cont.) Damaged inlet/outlet pipe 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.
Metal Grates (Catch Basins) 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
Damaged or missing grate Grate missing or broken member(s) of the grate. Any open structure requires urgent maintenance.
Grate is in place and meets design standards.
Manhole Cover/Lid 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.
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 STORMWATER FACILITIES AND ON-SITE BMPS
12/12/2016 2017 City of Renton Surface Water Design Manual A-12
NO. 6 – CONVEYANCE PIPES AND DITCHES
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITIONS WHEN
MAINTENANCE IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Pipes Sediment & debris accumulation Accumulated sediment or debris that exceeds 20% of the diameter of the pipe. Water flows freely through pipes.
Vegetation/root growth in pipe 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.
Damaged pipes 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.
Ditches 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 City personnel or the public.
Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City 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.
Excessive vegetation growth 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.
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 FOR STORMWATER FACILITIES AND ON-SITE BMPS
2017 City of Renton Surface Water Design Manual 12/12/2016 A-17
NO. 11 – GROUNDS (LANDSCAPING)
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITIONS WHEN
MAINTENANCE IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Site Trash and debris Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping.
Trash and debris cleared from site.
Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to City personnel or the public.
Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where City 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.
Excessive growth of grass/groundcover Grass or groundcover exceeds 18 inches in height. Grass or groundcover mowed to a height no greater than 6 inches.
Trees and Shrubs Hazard tree identified Any tree or limb of a tree identified as having a potential to fall and cause property damage or threaten human life. A hazard tree identified by a qualified arborist must be removed as soon as possible.
No hazard trees in facility.
Damaged tree or
shrub identified
Limbs or parts of trees or shrubs that are
split or broken which affect more than 25% of the total foliage of the tree or shrub.
Trees and shrubs with less than 5% of total
foliage with split or broken limbs.
Trees or shrubs that have been blown
down or knocked over.
No blown down vegetation or knocked over
vegetation. Trees or shrubs free of injury.
Trees or shrubs which are not adequately supported or are leaning over, causing exposure of the roots.
Tree or shrub in place and adequately supported; dead or diseased trees removed.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
12/12/2016 2017 City of Renton Surface Water Design Manual A-18
NO. 12 – ACCESS ROADS
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITION WHEN MAINTENANCE
IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Site Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 square feet (i.e., trash and debris would fill up one standards size garbage can).
Roadway drivable by maintenance vehicles.
Debris which could damage vehicle tires or prohibit use of road. Roadway drivable by maintenance vehicles.
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.
Blocked roadway Any obstruction which reduces clearance above road surface to less than 14 feet. Roadway overhead clear to 14 feet high.
Any obstruction restricting the access to a 10- to 12 foot width for a distance of more than 12 feet or any point restricting access to less than a 10 foot width.
At least 12-foot of width on access road.
Road Surface Erosion, settlement, potholes, soft spots,
ruts
Any surface defect which hinders or prevents maintenance access. Road drivable by maintenance vehicles.
Vegetation on road surface Trees or other vegetation prevent access to facility by maintenance vehicles. Maintenance vehicles can access facility.
Shoulders and Ditches Erosion Erosion within 1 foot of the roadway more than 8 inches wide and 6 inches deep. Shoulder free of erosion and matching the surrounding road.
Weeds and brush Weeds and brush exceed 18 inches in height or hinder maintenance access. Weeds and brush cut to 2 inches in height or cleared in such a way as to allow maintenance access.
Modular Grid Pavement 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.
Damaged or missing blocks/grids Access surface compacted because of broken on missing modular block. Access road surface restored so road infiltrates.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
2017 City of Renton Surface Water Design Manual 12/12/2016 A-41
NO. 30 – PERMEABLE PAVEMENT BMP
MAINTENANCE
COMPONENT
DEFECT OR
PROBLEM
CONDITIONS WHEN
MAINTENANCE IS NEEDED
RESULTS EXPECTED WHEN
MAINTENANCE IS PERFORMED
Preventive Surface cleaning/ vegetation control Media surface vacuumed or pressure washed annually, vegetation controlled to design maximum. Weed growth suggesting sediment accumulation.
No dirt, sediment, or debris clogging porous media, or vegetation limiting infiltration.
Porous Concrete, Porous Asphaltic Concrete, and Permeable Pavers
Trash and debris Trash and debris on the pavement interfering with infiltration; leaf drop in fall season.
No trash or debris interfering with infiltration.
Sediment accumulation Sediment accumulation on the pavement interfering with infiltration; runoff from adjacent areas depositing sediment/debris on pavement.
Pavement infiltrates as designed; adjacent areas stabilized.
Insufficient infiltration rate Pavement does not infiltrate at a rate of 10 inches per hour. Pavement infiltrates at a rate greater than 10 inches per hour.
Excessive ponding Standing water for a long period of time on the surface of the pavement. Standing water infiltrates at the desired rate.
Broken or cracked pavement Pavement is broken or cracked. No broken pavement or cracks on the surface of the pavement.
Settlement Uneven pavement surface indicating settlement of the subsurface layer. Pavement surface is uniformly level.
Moss growth Moss growing on pavement interfering with infiltration. No moss interferes with infiltration.
Inflow restricted Inflow to the pavement is diverted,
restricted, or depositing sediment and debris on the pavement.
Inflow to pavement is unobstructed and not
bringing sediment or debris to the pavement.
Underdrain not freely flowing Underdrain is not flowing when pavement has been infiltrating water. Underdrain flows freely when water is present.
Overflow not
controlling excess water
Overflow not controlling excess water to
desired location; native soil is exposed or other signs of erosion damage are present.
Overflow permits excess water to leave the
site at the desired location; Overflow is stabilized and appropriately armored.
Permeable Pavers Broken or missing pavers Broken or missing paving blocks on surface of pavement. No missing or broken paving blocks interfering with infiltration.
Uneven surface Uneven surface due to settlement or scour of fill in the interstices of the paving blocks. Pavement surface is uniformly level.
Compaction Poor infiltration due to soil compaction
between paving blocks.
No soil compaction in the interstices of the
paver blocks limiting infiltration.
Poor vegetation growth (if applicable) Grass in the interstices of the paving blocks is dead. Healthy grass is growing in the interstices of the paver blocks.
APPENDIX A MAINTENANCE REQUIREMENTS FOR STORMWATER FACILITIES AND ON-SITE BMPS
2017 City of Renton Surface Water Design Manual 12/12/2016 A-47
NO. 38 – SOIL AMENDMENT BMP
MAINTENANCE COMPONENT DEFECT OR PROBLEM CONDITIONS WHEN MAINTENANCE IS NEEDED RESULTS EXPECTED WHEN MAINTENANCE IS PERFORMED
Soil Media Unhealthy vegetation Vegetation not fully covering ground surface or vegetation health is poor.
Yellowing: possible Nitrogen (N) deficiency. Poor growth: possible
Phosphorous (P) deficiency. Poor flowering, spotting or curled leaves, or weak roots or stems: possible Potassium
(K) deficiency.
Plants are healthy and appropriate for site conditions
Inadequate soil nutrients and
structure
In the fall, return leaf fall and shredded woody materials from the landscape to the
site when possible
Soil providing plant nutrients and structure
Excessive vegetation growth Grass becomes excessively tall (greater than 10 inches); nuisance weeds and other
vegetation start to take over.
Healthy turf- “grasscycle” (mulch-mow or leave the clippings) to build turf health
Weeds Preventive maintenance Avoid use of pesticides (bug and weed killers), like “weed & feed,” which damage
the soil
Fertilizer needed Where fertilization is needed (mainly turf and annual flower beds), a moderate
fertilization program should be used which relies on compost, natural fertilizers or slow-release synthetic balanced fertilizers
Integrated Pest Management (IPM) protocols for fertilization followed
Bare spots Bare spots on soil No bare spots, area covered with
vegetation or mulch mixed into the underlying soil.
Compaction Poor infiltration due to soil compaction
• To remediate compaction, aerate
soil, till to at least 8-inch depth, or further amend soil with compost and
re-till
• If areas are turf, aerate compacted areas and top dress them with 1/4 to
1/2 inch of compost to renovate them
• If drainage is still slow, consider investigating alternative causes (e.g.,
high wet season groundwater levels, low permeability soils)
• Also consider site use and protection
from compacting activities
No soil compaction
Poor infiltration Soils become waterlogged, do not appear to be infiltrating. Facility infiltrating properly
Erosion/Scouring Erosion Areas of potential erosion are visible Causes of erosion (e.g., concentrate flow entering area, channelization of runoff) identified and damaged area stabilized (regrade, rock, vegetation, erosion control
matting).For deep channels or cuts (over 3 inches in ponding depth), temporary
erosion control measures in place until
permanent repairs can be made
Grass/Vegetation Unhealthy vegetation Less than 75% of planted vegetation is
healthy with a generally good appearance.
Healthy vegetation. Unhealthy plants
removed/replaced. Appropriate vegetation planted in terms of exposure, soil and soil
moisture.
Noxious Weeds Noxious weeds Listed noxious vegetation is present (refer to current County noxious weed list). No noxious weeds present.
Appendix
MITCHELL SHORT PLAT
AJOB #20-250
Technical Information Report
A.EXCERPT FROM PRELIMINARY MITCHELL SHORT PLAT REPORT WITH LEVEL 1 DOWNSTREAM ANALYSIS
PREPARED BY GOLDSMITH LAND DEVELOPMENT SERVICES DATED JANUARY 2020
Mitchell Preliminary Short Plat
Level 1 Downstream Analysis and
Preliminary Drainage Control Plan
January 2020
RECEIVED
02/11/2020 jding
PLANNING DIVISION
Mitchell Preliminary Short Plat January 2020 Level 1 Downstream Analysis and Preliminary Drainage Control Plan
r19133 Mitchell Technical Information Report 2020-01.docx 3
SPECIAL REQUIREMENTS
Special Requirement #1 – Other Adopted Area-Specific Requirements The site does not fall under any other known adopted area specific requirements.
Special Requirement #2 – Flood Hazard Area Delineation This project development is adjacent to a zone X flood hazard area per FEMA Flood Maps.
Special Requirement #3 – Flood Protection Facilities
This project does not rely on an existing flood protection facility for protection against hazards posed
by erosion or inundation or propose to modify or construct a new flood protection facility; therefore, flood protection facilities are not required.
Special Requirement #4 – Source Control The proposed development does not require a commercial building or commercial site development
permit; Therefore, water quality source control is not required. Special Requirement #5 – Oil Control
This project does not have high use site characteristics; therefore, oil control BMP’s are not required. Special Requirement #6 – Aquifer Protection Area
This project does not have high use site characteristics; therefore, oil control BMP’s are not required.
2.0 Off-Site Analysis
The following is a Level 1 downstream analysis, performed in accordance with the 2017 City of
Renton SWDM. A site visit was conducted by Goldsmith Engineering on January 7, 2020 to investigate the onsite drainage systems, confirm downstream drainage paths, and evaluate
upstream tributary areas to the project site. The weather during the site visit was cloudy and wet
with a temperature of approximately 45 degrees Fahrenheit.
Task 1 – Define and Map Study Area
The topographical field survey was supplemented by City of Renton GIS drainage information, aerial
mapping, and information obtained by field investigation to further define and map the study area in
order to prepare the offsite analysis.
Task 2 – Information Review
As mentioned earlier, the City of Renton drainage maps show the project area within the May Creek Basin. Based on the City of Renton GIS mapping data, there are no critical areas located on or
adjacent to the subject site. This on-site and adjacent evaluation includes streams, wetlands, floodplains, steep slopes, landslide hazard areas, and seismic hazard areas. Per the COR GIS data
and the site visit, there are no drainage problems within the downstream system. According to the
Washington State Department of Ecology Flood Hazard Maps, the project area is not located within a Floodway or 100-year Floodplain.
Mitchell Preliminary Short Plat January 2020 Level 1 Downstream Analysis and Preliminary Drainage Control Plan
r19133 Mitchell Technical Information Report 2020-01.docx 4
Task 3 – Field Inspection
The project area slopes northeast with slopes ranging from 5% to 15%. There is an existing single family home to remain and a new single-family residence is proposed east of the existing residence.
The rest of the property is covered by grass, and scattered bushes and trees.
Task 4 – Drainage System Description and Problem Descriptions
The downstream drainage path was determined based on City of Renton GIS storm drainage maps, site survey, and information gathered during a site visit. Refer to Figure 5 – Downstream Drainage
Map. As previously stated, runoff from the site flows northeast towards Meadow Ave N. The
proposed drainage improvements will treat stormwater runoff on-site to the maximum extend feasible before discharging stormwater to the existing closed system within Meadow Ave N.
1. Runoff is discharged from the site.
2. Stormwater sheetflows north along Meadow Ave N.
3. Runoff is collected by the public stormwater system within Meadow Ave N and piped north
via a 10-inch closed system.
4. Stormwater keeps traveling north via a 12-inch pipe.
5. Runoff discharges to an existing catch basin and travels north along Meadow Ave N. through
an 18-inch pipe system.
6. Stormwater travels west along N 40th St via an 18-inch closed pipe system.
7. Stormwater travels northwest starting at the intersection of Lake Washington Blvd N and N
40th St. through a concrete culvert
8. Runoff continues flow southwest through a 30-inch pipe
9. Stormwater eventually out falls to Lake Washington.
Task 5 – Mitigation of Existing or Potential Problems
As indicated previously, there are no existing problems on-site or downstream of the site. The
design of a stormwater control plan meeting the City of Renton requirements, including recommended BMPs will mitigate any potential problems related to the development of the subject
site.
Mitchell Preliminary Short Plat January 2020 Level 1 Downstream Analysis and Preliminary Drainage Control Plan
r19133 Mitchell Technical Information Report 2020-01.docx 5
OFF-SITE ANALYSIS DRAINAGE SYSTEM TABLE -1
Surface Water Design Manual, Core Requirement #2
Basin: Lake Washington Watershed Sub-basin Name: East Lake Washington
Symbol Drainage Component Type, Name, and Size
Drainage Component Description Slope (estimated) Distance from site discharge
Existing Problems Potential Problems Observations of field inspector, resource
reviewer, or resident
1 Site Boundary Property line N/A 0 None None N/A
2 Sheet Flow Sheet Flow to Closed Storm System 0.5 to 12% 0 to 90 ft None None No signs of major sediment, ponding, or
flooding
3 Conveyance System Existing 10-inch pipe 0.5 to 12% 90 to 125 ft None Under Capacity No capacity problems were observed during site
visit
4 Conveyance System Existing 12-inch pipe 0.5 to 7% 125 to 265 ft None Under Capacity No capacity problems were observed during site visit
5 Conveyance System Existing 18-inch pipe 0.5 to 7% 265 to 1,000 ft None Under Capacity No capacity problems were observed during site visit
6 Conveyance System Existing 18-inch pipe 0.5 to 7% 1,000 to 2,100 ft None Under Capacity No capacity problems were observed during site visit
7 Conveyance System Existing concrete culvert 0.5 to 7% 2,100 to 2,200 ft None Under Capacity No capacity problems were observed during site visit
8 Conveyance System Existing 30-inch pipe 0.5 to 7% 2,200 to 2,440 ft None Under Capacity No capacity problems were observed during site visit
9 Lake Lake Washington N/A +/-2,440 ft None Sedimentation,
flooding
No signs of major sediment, ponding, or flooding
Figures
Vicinity Map
3625 Meadow Ave N, City of Renton, WA 98056 Tax Parcel 3342700480
FIGURE 1
North
Not to Scale
Site
Pictometry, King County, King County
FIGURE 2 - SITE AERIAL
Date: 10/14/2019
Notes:±The information included on this map has been compiled by King County staff from a variety of sources and is subject to change without notice. King Countymakes no representations or warranties, express or implied, as to accuracy, completeness, timeliness, or rights to the use of such information. This document isnot intended for use as a survey product. King County shall not be liable for any general, special, indirect, incidental, or consequential damages including,but not limited to, lost revenues or lost profits resulting from the use or misuse of the information contained on this map. Any sale of this map or information onthis map is prohibited except by written permission of King County.
SITE
United States
Department of
Agriculture
A product of the National
Cooperative Soil Survey,
a joint effort of the United
States Department of
Agriculture and other
Federal agencies, State
agencies including the
Agricultural Experiment
Stations, and local
participants
Custom Soil Resource
Report for
King County
Area,
Washington
Mitchell Property
Natural
Resources
Conservation
Service
October 14, 2019Figure 3
9
Custom Soil Resource Report
Soil Map
52637305263740526375052637605263770526378052637905263800526381052638205263730526374052637505263760526377052637805263790526380052638105263820560170 560180 560190 560200 560210 560220 560230 560240 560250 560260 560270 560280 560290 560300 560310
560170 560180 560190 560200 560210 560220 560230 560240 560250 560260 560270 560280 560290 560300 560310
47° 31' 30'' N 122° 12' 2'' W47° 31' 30'' N122° 11' 55'' W47° 31' 26'' N
122° 12' 2'' W47° 31' 26'' N
122° 11' 55'' WN
Map projection: Web Mercator Corner coordinates: WGS84 Edge tics: UTM Zone 10N WGS84
0 30 60 120 180
Feet
0 10 20 40 60
Meters
Map Scale: 1:690 if printed on A landscape (11" x 8.5") sheet.
Soil Map may not be valid at this scale.
Figure 3
MAP LEGEND MAP INFORMATION
Area of Interest (AOI)
Area of Interest (AOI)
Soils
Soil Map Unit Polygons
Soil Map Unit Lines
Soil Map Unit Points
Special Point Features
Blowout
Borrow Pit
Clay Spot
Closed Depression
Gravel Pit
Gravelly Spot
Landfill
Lava Flow
Marsh or swamp
Mine or Quarry
Miscellaneous Water
Perennial Water
Rock Outcrop
Saline Spot
Sandy Spot
Severely Eroded Spot
Sinkhole
Slide or Slip
Sodic Spot
Spoil Area
Stony Spot
Very Stony Spot
Wet Spot
Other
Special Line Features
Water Features
Streams and Canals
Transportation
Rails
Interstate Highways
US Routes
Major Roads
Local Roads
Background
Aerial Photography
The soil surveys that comprise your AOI were mapped at
1:24,000.
Warning: Soil Map may not be valid at this scale.
Enlargement of maps beyond the scale of mapping can cause
misunderstanding of the detail of mapping and accuracy of soil
line placement. The maps do not show the small areas of
contrasting soils that could have been shown at a more detailed
scale.
Please rely on the bar scale on each map sheet for map
measurements.
Source of Map: Natural Resources Conservation Service
Web Soil Survey URL:
Coordinate System: Web Mercator (EPSG:3857)
Maps from the Web Soil Survey are based on the Web Mercator
projection, which preserves direction and shape but distorts
distance and area. A projection that preserves area, such as the
Albers equal-area conic projection, should be used if more
accurate calculations of distance or area are required.
This product is generated from the USDA-NRCS certified data as
of the version date(s) listed below.
Soil Survey Area: King County Area, Washington
Survey Area Data: Version 15, Sep 16, 2019
Soil map units are labeled (as space allows) for map scales
1:50,000 or larger.
Date(s) aerial images were photographed: Jul 1, 2019—Jul 25,
2019
The orthophoto or other base map on which the soil lines were
compiled and digitized probably differs from the background
imagery displayed on these maps. As a result, some minor
shifting of map unit boundaries may be evident.
Custom Soil Resource Report
10
Figure 3
Map Unit Legend
Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI
InC Indianola loamy sand, 5 to 15
percent slopes
1.2 100.0%
Totals for Area of Interest 1.2 100.0%
Map Unit Descriptions
The map units delineated on the detailed soil maps in a soil survey represent the
soils or miscellaneous areas in the survey area. The map unit descriptions, along
with the maps, can be used to determine the composition and properties of a unit.
A map unit delineation on a soil map represents an area dominated by one or more
major kinds of soil or miscellaneous areas. A map unit is identified and named
according to the taxonomic classification of the dominant soils. Within a taxonomic
class there are precisely defined limits for the properties of the soils. On the
landscape, however, the soils are natural phenomena, and they have the
characteristic variability of all natural phenomena. Thus, the range of some
observed properties may extend beyond the limits defined for a taxonomic class.
Areas of soils of a single taxonomic class rarely, if ever, can be mapped without
including areas of other taxonomic classes. Consequently, every map unit is made
up of the soils or miscellaneous areas for which it is named and some minor
components that belong to taxonomic classes other than those of the major soils.
Most minor soils have properties similar to those of the dominant soil or soils in the
map unit, and thus they do not affect use and management. These are called
noncontrasting, or similar, components. They may or may not be mentioned in a
particular map unit description. Other minor components, however, have properties
and behavioral characteristics divergent enough to affect use or to require different
management. These are called contrasting, or dissimilar, components. They
generally are in small areas and could not be mapped separately because of the
scale used. Some small areas of strongly contrasting soils or miscellaneous areas
are identified by a special symbol on the maps. If included in the database for a
given area, the contrasting minor components are identified in the map unit
descriptions along with some characteristics of each. A few areas of minor
components may not have been observed, and consequently they are not
mentioned in the descriptions, especially where the pattern was so complex that it
was impractical to make enough observations to identify all the soils and
miscellaneous areas on the landscape.
The presence of minor components in a map unit in no way diminishes the
usefulness or accuracy of the data. The objective of mapping is not to delineate
pure taxonomic classes but rather to separate the landscape into landforms or
landform segments that have similar use and management requirements. The
delineation of such segments on the map provides sufficient information for the
development of resource plans. If intensive use of small areas is planned, however,
onsite investigation is needed to define and locate the soils and miscellaneous
areas.
Custom Soil Resource Report
11 Figure 3
4,514752
City of Renton Downstream Map
This map is a user generated static output from an Internet mapping site and
is for reference only. Data layers that appear on this map may or may not be
accurate, current, or otherwise reliable.
THIS MAP IS NOT TO BE USED FOR NAVIGATIONWGS_1984_Web_Mercator_Auxiliary_Sphere
Notes
None
01/02/2020
Legend
512 0 256 512 Feet
Information Technology - GIS
RentonMapSupport@Rentonwa.gov
Network Structures
Access Riser
Inlet
Manhole
Utility Vault
Clean Out
Unknown
Control Structures
Pump Stations
Discharge Points
Water Quality
Detention Facilities
Pond
Tank
Vault
Bioswale
Wetland
Other
Stormwater Mains
Culverts
Open Drains
Facility Outlines
Private Network Structures
Access Riser
Inlet
Manhole
Clean Out
Utility Vault
Unknown
Private Control Structures
Private Pump Stations
Private Discharge Points
Private Water Quality
Private Detention Facilities
Tank, No
Stormwater Wetland, No; Natural Wetland, No
Filter Strip, No
Infiltration Trench, No
Vault, No
Pond, No; Pond, Unknown
Bioswale, No
Stormtech Chamber, No
Other, No
Private Pipes
Private Culverts
Private Open Drains
Private Facility Outlines
Drainage Complaints
Known Drainage Issues
Renton
King County
Streets
Points of Interest
Parks
Waterbodies
Extent2010
1
2
3
4
5
67
8
9
SITE
APPROX. 1/4 MILE
DOWNSTREAM
FROM SITE
Figure 5
4,514752
City of Renton Drainage Complaints
This map is a user generated static output from an Internet mapping site and
is for reference only. Data layers that appear on this map may or may not be
accurate, current, or otherwise reliable.
THIS MAP IS NOT TO BE USED FOR NAVIGATIONWGS_1984_Web_Mercator_Auxiliary_Sphere
Notes
None
01/02/2020
Legend
512 0 256 512 Feet
Information Technology - GIS
RentonMapSupport@Rentonwa.gov
Network Structures
Access Riser
Inlet
Manhole
Utility Vault
Clean Out
Unknown
Control Structures
Pump Stations
Discharge Points
Water Quality
Detention Facilities
Pond
Tank
Vault
Bioswale
Wetland
Other
Stormwater Mains
Culverts
Open Drains
Facility Outlines
Drainage Complaints
Known Drainage Issues
Renton
King County
Streets
Points of Interest
Parks
Waterbodies
Extent2010
SITE
MITCHELL SHORT PLAT
BJOB #20-250
Technical Information Report
B.FULL WWHM REPORT OUTPUT – DETENTION EXEMPTION
WWHM2012
PROJECT REPORT
20250 Detention Exemption 3/18/2021 6:14:49 PM Page 2
General Model Information
Project Name:20250 Detention Exemption
Site Name:
Site Address:
City:
Report Date:3/18/2021
Gage:Seatac
Data Start:1948/10/01
Data End:2009/09/30
Timestep:15 Minute
Precip Scale:1.000
Version Date:2019/09/13
Version:4.2.17
POC Thresholds
Low Flow Threshold for POC1:50 Percent of the 2 Year
High Flow Threshold for POC1:50 Year
20250 Detention Exemption 3/18/2021 6:14:49 PM Page 3
Landuse Basin Data
Predeveloped Land Use
Basin 1
Bypass:No
GroundWater:No
Pervious Land Use acre
C, Lawn, Mod 0.77
Pervious Total 0.77
Impervious Land Use acre
ROADS FLAT 0.11
ROOF TOPS FLAT 0.05
Impervious Total 0.16
Basin Total 0.93
Element Flows To:
Surface Interflow Groundwater
20250 Detention Exemption 3/18/2021 6:14:49 PM Page 4
Mitigated Land Use
Basin 1
Bypass:No
GroundWater:No
Pervious Land Use acre
C, Lawn, Mod 0.45
Pervious Total 0.45
Impervious Land Use acre
ROADS MOD 0.07
ROOF TOPS FLAT 0.41
Impervious Total 0.48
Basin Total 0.93
Element Flows To:
Surface Interflow Groundwater
20250 Detention Exemption 3/18/2021 6:14:49 PM Page 5
Routing Elements
Predeveloped Routing
20250 Detention Exemption 3/18/2021 6:14:49 PM Page 6
Mitigated Routing
20250 Detention Exemption 3/18/2021 6:14:49 PM Page 7
Analysis Results
POC 1
+ Predeveloped x Mitigated
Predeveloped Landuse Totals for POC #1
Total Pervious Area:0.77
Total Impervious Area:0.16
Mitigated Landuse Totals for POC #1
Total Pervious Area:0.45
Total Impervious Area:0.48
Flow Frequency Method:Log Pearson Type III 17B
Flow Frequency Return Periods for Predeveloped. POC #1
Return Period Flow(cfs)
2 year 0.128267
5 year 0.197117
10 year 0.249117
25 year 0.322107
50 year 0.381809
100 year 0.446122
Flow Frequency Return Periods for Mitigated. POC #1
Return Period Flow(cfs)
2 year 0.222271
5 year 0.297018
10 year 0.35005
25 year 0.421222
50 year 0.477346
100 year 0.536195
Annual Peaks
Annual Peaks for Predeveloped and Mitigated. POC #1
Year Predeveloped Mitigated
1949 0.221 0.325
1950 0.226 0.294
1951 0.128 0.196
1952 0.070 0.137
1953 0.059 0.152
1954 0.101 0.182
1955 0.103 0.201
1956 0.112 0.193
1957 0.152 0.242
1958 0.085 0.175
20250 Detention Exemption 3/18/2021 6:15:45 PM Page 8
1959 0.072 0.161
1960 0.135 0.206
1961 0.114 0.196
1962 0.066 0.154
1963 0.118 0.198
1964 0.103 0.175
1965 0.161 0.252
1966 0.078 0.148
1967 0.222 0.289
1968 0.173 0.317
1969 0.145 0.228
1970 0.117 0.209
1971 0.145 0.252
1972 0.207 0.291
1973 0.063 0.131
1974 0.151 0.243
1975 0.160 0.247
1976 0.111 0.186
1977 0.100 0.176
1978 0.121 0.213
1979 0.105 0.279
1980 0.264 0.350
1981 0.118 0.225
1982 0.242 0.349
1983 0.131 0.243
1984 0.087 0.163
1985 0.120 0.224
1986 0.124 0.197
1987 0.116 0.275
1988 0.052 0.157
1989 0.065 0.208
1990 0.428 0.514
1991 0.295 0.388
1992 0.095 0.163
1993 0.059 0.132
1994 0.046 0.134
1995 0.100 0.198
1996 0.203 0.257
1997 0.148 0.229
1998 0.115 0.199
1999 0.321 0.488
2000 0.132 0.225
2001 0.086 0.217
2002 0.206 0.308
2003 0.176 0.259
2004 0.281 0.449
2005 0.122 0.197
2006 0.121 0.183
2007 0.394 0.466
2008 0.284 0.375
2009 0.165 0.244
Ranked Annual Peaks
Ranked Annual Peaks for Predeveloped and Mitigated. POC #1
Rank Predeveloped Mitigated
1 0.4276 0.5141
2 0.3943 0.4876
3 0.3212 0.4659
20250 Detention Exemption 3/18/2021 6:15:45 PM Page 9
4 0.2949 0.4487
5 0.2840 0.3877
6 0.2810 0.3750
7 0.2640 0.3496
8 0.2420 0.3494
9 0.2258 0.3250
10 0.2218 0.3167
11 0.2214 0.3078
12 0.2070 0.2937
13 0.2064 0.2908
14 0.2031 0.2891
15 0.1765 0.2793
16 0.1734 0.2754
17 0.1648 0.2588
18 0.1612 0.2567
19 0.1602 0.2522
20 0.1517 0.2517
21 0.1515 0.2468
22 0.1476 0.2442
23 0.1452 0.2429
24 0.1445 0.2428
25 0.1352 0.2420
26 0.1317 0.2290
27 0.1307 0.2282
28 0.1279 0.2249
29 0.1241 0.2248
30 0.1220 0.2240
31 0.1212 0.2171
32 0.1209 0.2134
33 0.1196 0.2090
34 0.1180 0.2075
35 0.1179 0.2060
36 0.1169 0.2013
37 0.1159 0.1986
38 0.1147 0.1984
39 0.1136 0.1975
40 0.1119 0.1970
41 0.1113 0.1969
42 0.1054 0.1958
43 0.1032 0.1957
44 0.1026 0.1931
45 0.1015 0.1856
46 0.1005 0.1831
47 0.0997 0.1819
48 0.0952 0.1755
49 0.0874 0.1751
50 0.0858 0.1746
51 0.0849 0.1631
52 0.0776 0.1627
53 0.0719 0.1608
54 0.0702 0.1570
55 0.0663 0.1535
56 0.0648 0.1523
57 0.0634 0.1483
58 0.0594 0.1371
59 0.0586 0.1340
60 0.0522 0.1318
61 0.0463 0.1313
20250 Detention Exemption 3/18/2021 6:15:45 PM Page 10
20250 Detention Exemption 3/18/2021 6:15:45 PM Page 11
Duration Flows
Flow(cfs)Predev Mit Percentage Pass/Fail
0.0641 1148 7807 680 Fail
0.0673 997 6906 692 Fail
0.0706 859 6064 705 Fail
0.0738 737 5371 728 Fail
0.0770 644 4785 743 Fail
0.0802 544 4072 748 Fail
0.0834 487 3675 754 Fail
0.0866 441 3268 741 Fail
0.0898 393 2937 747 Fail
0.0930 348 2550 732 Fail
0.0962 320 2301 719 Fail
0.0994 294 2088 710 Fail
0.1026 268 1879 701 Fail
0.1058 250 1705 682 Fail
0.1091 226 1511 668 Fail
0.1123 208 1398 672 Fail
0.1155 189 1258 665 Fail
0.1187 175 1156 660 Fail
0.1219 162 1064 656 Fail
0.1251 144 939 652 Fail
0.1283 129 865 670 Fail
0.1315 119 792 665 Fail
0.1347 111 734 661 Fail
0.1379 108 678 627 Fail
0.1411 102 607 595 Fail
0.1444 99 562 567 Fail
0.1476 92 524 569 Fail
0.1508 89 498 559 Fail
0.1540 82 455 554 Fail
0.1572 79 426 539 Fail
0.1604 77 395 512 Fail
0.1636 71 373 525 Fail
0.1668 67 351 523 Fail
0.1700 66 326 493 Fail
0.1732 62 307 495 Fail
0.1764 57 292 512 Fail
0.1797 53 275 518 Fail
0.1829 47 265 563 Fail
0.1861 47 235 500 Fail
0.1893 44 224 509 Fail
0.1925 44 209 475 Fail
0.1957 41 199 485 Fail
0.1989 41 185 451 Fail
0.2021 41 171 417 Fail
0.2053 39 163 417 Fail
0.2085 33 148 448 Fail
0.2117 33 141 427 Fail
0.2149 32 133 415 Fail
0.2182 29 123 424 Fail
0.2214 29 120 413 Fail
0.2246 26 111 426 Fail
0.2278 24 107 445 Fail
0.2310 22 105 477 Fail
0.2342 21 102 485 Fail
20250 Detention Exemption 3/18/2021 6:15:45 PM Page 12
0.2374 21 99 471 Fail
0.2406 20 93 465 Fail
0.2438 19 85 447 Fail
0.2470 18 82 455 Fail
0.2502 16 79 493 Fail
0.2535 16 75 468 Fail
0.2567 16 75 468 Fail
0.2599 16 70 437 Fail
0.2631 14 66 471 Fail
0.2663 13 65 500 Fail
0.2695 12 61 508 Fail
0.2727 12 58 483 Fail
0.2759 12 55 458 Fail
0.2791 10 48 480 Fail
0.2823 9 46 511 Fail
0.2855 8 46 575 Fail
0.2888 7 43 614 Fail
0.2920 7 39 557 Fail
0.2952 6 37 616 Fail
0.2984 6 35 583 Fail
0.3016 5 34 680 Fail
0.3048 5 33 660 Fail
0.3080 5 31 620 Fail
0.3112 5 31 620 Fail
0.3144 5 29 580 Fail
0.3176 5 25 500 Fail
0.3208 4 25 625 Fail
0.3240 3 25 833 Fail
0.3273 3 23 766 Fail
0.3305 2 22 1100 Fail
0.3337 2 21 1050 Fail
0.3369 2 20 1000 Fail
0.3401 2 20 1000 Fail
0.3433 2 19 950 Fail
0.3465 2 19 950 Fail
0.3497 2 19 950 Fail
0.3529 2 15 750 Fail
0.3561 2 15 750 Fail
0.3593 2 15 750 Fail
0.3626 2 15 750 Fail
0.3658 2 15 750 Fail
0.3690 2 15 750 Fail
0.3722 2 14 700 Fail
0.3754 2 14 700 Fail
0.3786 2 12 600 Fail
0.3818 2 12 600 Fail
The development has an increase in flow durations
from 1/2 Predeveloped 2 year flow to the 2 year flow
or more than a 10% increase from the 2 year to the 50
year flow.
The development has an increase in flow durations for
more than 50% of the flows for the range of the
duration analysis.
20250 Detention Exemption 3/18/2021 6:15:45 PM Page 13
Water Quality
Water Quality BMP Flow and Volume for POC #1
On-line facility volume:0 acre-feet
On-line facility target flow:0 cfs.
Adjusted for 15 min:0 cfs.
Off-line facility target flow:0 cfs.
Adjusted for 15 min:0 cfs.
20250 Detention Exemption 3/18/2021 6:15:45 PM Page 14
LID Report
20250 Detention Exemption 3/18/2021 6:16:20 PM Page 15
Model Default Modifications
Total of 0 changes have been made.
PERLND Changes
No PERLND changes have been made.
IMPLND Changes
No IMPLND changes have been made.
20250 Detention Exemption 3/18/2021 6:16:21 PM Page 16
Appendix
Predeveloped Schematic
20250 Detention Exemption 3/18/2021 6:16:22 PM Page 17
Mitigated Schematic
20250 Detention Exemption 3/18/2021 6:16:23 PM Page 18
Predeveloped UCI File
20250 Detention Exemption 3/18/2021 6:16:23 PM Page 19
Mitigated UCI File
20250 Detention Exemption 3/18/2021 6:16:23 PM Page 20
Predeveloped HSPF Message File
20250 Detention Exemption 3/18/2021 6:16:23 PM Page 21
Mitigated HSPF Message File
20250 Detention Exemption 3/18/2021 6:16:23 PM Page 22
Disclaimer
Legal Notice
This program and accompanying documentation are provided 'as-is' without warranty of any kind. The
entire risk regarding the performance and results of this program is assumed by End User. Clear
Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either
expressed or implied, including but not limited to implied warranties of program and accompanying
documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever
(including without limitation to damages for loss of business profits, loss of business information,
business interruption, and the like) arising out of the use of, or inability to use this program even
if Clear Creek Solutions Inc. or their authorized representatives have been advised of the
possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005-2021; All
Rights Reserved.
Clear Creek Solutions, Inc.
6200 Capitol Blvd. Ste F
Olympia, WA. 98501
Toll Free 1(866)943-0304
Local (360)943-0304
www.clearcreeksolutions.com