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Home My WebLink AboutRS_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. LakeDesire ShadyLake (MudLake) PantherLake LakeYoungs LakeWashington B l a ck Ri ver Gr een Riv e r C edarRi verUV900 UV167 UV515 UV169 UV900 UV169 UV167BN IncBN IncBBNNIInnccSSEERReennttoonnIIssssaaqquuaahh RR dd RReennttoonnMMaapplleeVVaalllleeyyRRdd MMaapplleeVVaalllleeyyHHwwyy 110088tthhAAvveeSSEESSWWSSuunnsseettBBllvvdd RRaaii nnii eerr AAvveeNNNE 3rd StNE 3rd St SW 43rd StSW 43rd St SSEE CCaarrrrRR dd NE 4th StNE 4th St SSEERReennttoonn MMaappllee VVaalllleeyy RRddLLooggaannAAvveeNN SR 515SR 515PPaarrkkAAvveeNNOOaakkeessddaalleeAAvveeSSWWSSuunnsseettBBllvvddNNEE DDuuvvaallllAAvveeNNEEI-405 FWYI-405 FWY II--440055FFWWYYSR 167SR 167114400tthh WWaayySS EE NNEE2277tthhSStt 115566tthhAAvveeSSEEUUnniioonnAAvveeNNEE111166tthhAAvveeSSEESW 7th StSW 7th St N 8th StN 8th St PP uuggeettDDrrSSEE RR eennttoonnAAvvee SS SSWW 2277tthh SStt BBeennssoonnRRddSSWWiilllliiaammssAAvveeSSMMoonnrrooeeAAvveeNNEESE 128th StSE 128th St II nntt eerr uurr bbaannAAvveeSS HHooqquuiiaammAAvveeNNEE8844tthhAAvveeSSSSEEPPeett rr oovviitt sskkyyRRddEEVVaalllleeyyHHwwyySE 192nd StSE 192nd St SE 60th StSE 60th St TTaallbboottRRddSSRR ee nntt oo nn AAvveeSS116644tthhAAvveeSSEESE 208th StSE 208th St SE 72nd StSE 72nd St RRaaiinniieerrAAvvee SS 111166tthhAAvveeSSEES 128th StS 128th St NNeewwccaassttllee WWaayy SS 221122tthh SStt SS118800tthh SStt CCooaall CCrreeeekkPPkkwwyySSEESW 41st StSW 41st St 114400tthhAAvveeSSEE112288tthhAAvveeSSEE6688tthhAAvveeSSSSEE 116688tthh SStt NE 12th StNE 12th St BBee aa ccoonn AA vv ee SS FFoorreessttDDrr SSEE SSEE 116644tthh SStt 114488tthhAAvveeSSEESSEEMMaayy VVaalllleeyyRRdd SS EE JJoonneess RRdd SSEE 22 00 44 tthh WW aayySW 34th StSW 34th St SE 144th StSE 144th St 114488tthhAAvveeSSEE115544tthhPPllSSEELL aa kk ee WWaa sshhii nnggtt oonnBBll vvddNNEEddmmoonnddssAAvveeNNEEAAbbeerrddeeeennAAvveeNNEEEEMM eerrcceerrWWaayyWWeessttVVaalllleeyyHHwwyyEast Valley RdEast Valley Rd,§-405 ,§-405 ,§-405 µ0 1 2Miles 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 BBNNIInncc0055FFWWYYSITE 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 5.1JOB #20-250 Technical Information Report 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