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Effective Engineering (EE2022-63) Technical Information Report Page 1 SB INDEX SFR LLC Renton, Washington TECHNICAL INFORMATION REPORT for PROPOSED SINGLE-FAMILY RESIDENCE 2900 NE 5th PL, Renton, WA 98056 on Parcel # 722780-0631 06-03-2023 Effective Engineering PLLC, Project No. EE2022-63 Applicant: DON BORA Tel: 206-859-3094 Email: Don@bluelam.com Report Prepared by: Effective Engineering PLLC 8627 NE 180th St Bothell, WA 98011 (206) 303-7639 Report Issue/Revise Date Jun 03, 2023 SURFACE WATER UTILITY jfarah 11/15/2023 DEVELOPMENT ENGINEERING yqi 11/27/2023 Effective Engineering (EE2022-63) Technical Information Report Page 2 SB INDEX SFR LLC Renton, Washington TECHNICAL INFORMATION REPORT TABLE OF CONTENTS SECTION I ............................................................................................................ 4 Project Overview .............................................................................................................. 4 Predeveloped Site Conditions .......................................................................................... 4 Developed Site Conditions ............................................................................................... 5 SECTION II ......................................................................................................... 17 Conditions and Requirements Summary ....................................................................... 17 SECTION III ........................................................................................................ 21 Offsite Analysis ............................................................................................................... 21 Task 1: Define and map the study area ...................................................................... 21 Task 2: Review all available information on the study area ....................................... 21 Task 3: Field Inspect the study area ........................................................................... 21 Task 4: Describe the drainage system, and its existing and predicted drainage and water quality problems ............................................................................................... 21 SECTION IV ........................................................................................................ 24 Flow Control, Low Impact Development (LID) and Water Quality Facility Analysis and Design ............................................................................................................................. 24 Existing Site Hydrology ............................................................................................... 24 Developed Site Hydrology .......................................................................................... 24 Performance Standards .............................................................................................. 24 Flow Control System ................................................................................................... 25 Water Quality System ................................................................................................. 25 SECTION V ......................................................................................................... 25 Conveyance System Analysis and Design (Per Chapter 4) ............................................. 25 SECTION VI ........................................................................................................ 25 Special Reports and Studies ........................................................................................... 25 SECTION VII ....................................................................................................... 25 Other Permits (per 2.2.5) ............................................................................................... 25 SECTION VIII ...................................................................................................... 26 CSWPP Plan Analysis and Design ................................................................................... 26 ESC Plan Analysis and Design ...................................................................................... 26 Effective Engineering (EE2022-63) Technical Information Report Page 3 SB INDEX SFR LLC Renton, Washington SECTION IX ........................................................................................................ 27 Bond Quantities, Facility Summaries and Declaration of Covenant .............................. 27 Bond Quantities Worksheet ....................................................................................... 27 Flow Control and Water Quality Facility Summary Sheet and Sketch ....................... 27 SECTION X ......................................................................................................... 28 Operations and Maintenance Manual ........................................................................... 28 APPENDIX: BMPS .............................................................................................. 31 List of Figures Figure 1 TIR Worksheet ....................................................................................................... 8 Figure 2 Site Location ........................................................................................................ 14 Figure 3 Drainage Basins, Subbasins and Site Characteristics .......................................... 15 Figure 4 Soils ...................................................................................................................... 16 Figure 5 Sensitive Area Map .............................................................................................. 22 Figure 6 Utilities Map ........................................................................................................ 23 Appendix A: BMPs Attachments Attachment A: WWHM Printout Attachment B: Geotechnical Report Attachment C: CSWPP Attachment E: Bond Quantities Worksheet Effective Engineering (EE2022-63) Technical Information Report Page 4 SB INDEX SFR LLC Renton, Washington SECTION I PROJECT OVERVIEW This storm drainage technical information report has been prepared for the proposed new development single-family residence located at 2900 NE 5th PL, Renton, WA 98056 on parcel # 722780-0631. The site consists of a newly subdivided lot from 2906 NE 5th Place. The Project will meet the drainage requirements of the 2022 City of Renton Surface Water Design Manual. The Legal Description is: LOT 2, CITY OF RENTON SHORT PLAT NO. LUA18-000445, RECORDING NO. 20181113900001, RECORDS OF KING COUNTY, WASHINGTON PREDEVELOPED SITE CONDITIONS The 5,682sf site (0.13 acres) is located at the NE corner of intersection of NE 5th PL and INDEX AVE NE at 2900 NE 5th PL, Renton, WA 98056. The site has no existing development except a concrete driveway extending to 2906 NE 5th Place. The rest of site is covered with grass. The existing drive is 756sf, 13.3%. The existing drive will be demolished. The site is bordered by NE 5th PL on the South, Index Ave NE west, and single-family houses on the North and East. The site has 15% to 28% steep slopes east to west and drains toward Index Avenue to the catch basin on the corner of intersection, continue as it does in city drainage system. Existing hard surface to be replaced Existing drive way to be removed (Sf) 756 Total Ex. Impervious area (SF) 756 Total Ex. Impervious area coverage (%) 13.3% The City of Renton Map shows that the site is not located in coal mine area, wetland, erosion hazard areas, critical aquifer recharge area, and other environmentally sensitive areas (see figure 6, the City of Renton sensitive area map). But the site has Regulated Slopes within the northeast portion of the site This lot is in the Urban Growth Area. Per King County Imap, there is no drainage complaint upstream and downstream Drainage Basin= East Lake Washington - Renton; Watershed = Cedar River / Lake Washington; WRIA=Cedar-Sammamish (8) Quarter-Section-Township-Range = SW - 9 - 23 – 5 The current stormwater runoff of the site flows onto Index Ave NE and NE 5th PL, and finally to the catch basin at SW corner of the site to the city storm drainage system on the NE 5th PL as the yellow path line is shown in the city stormwater utilities map Fig 6. Effective Engineering (EE2022-63) Technical Information Report Page 5 SB INDEX SFR LLC Renton, Washington DEVELOPED SITE CONDITIONS The total area of parcel is 5,682 Sq Ft (0.130 acre). As per part of frontage development 1’-6” width along Index Ave, 101 Sq. Ft (0.002 acre) will be changed to ROW dedicated. The target area for the development will be remaining 5581 Sq. Ft. (0.128 acre). The proposed project involves new construction of single-family residence with 1,591 sf of building roof, and 788 sf parking and walkways; total 2,379 sq ft of impervious surface is proposed. The proposed development is adding total 2,379 sq ft of hard surface and remaining 3,202 sq ft will be landscaping which will result 42.6% impervious of total lot of 5581 Sq. Ft . Frontage of site will be developed to add 5’ wide side walk included 8’ planter along the 0.5’ curb of NE 5th PL and INDEX AVE NE. As per part of frontage development, 101 sf of parcel will be changed to ROW dedicated on side of INDEX AVE NE. Total 1002 sq. ft of concrete walk way and drive access will be added as new impervious surface on ROW. Impervious Surfaces: Existing Covered area Total site area 5,682 sq. Ft (0.130 acre) Existing impervious area (drive) 756 sq. Ft (0.017 acre) Existing pervious area 4,926 sq. Ft Proposed new/replaced impervious area Total site area (minus Dedicated ROW) 5,581 sq. Ft (0.128 acre) Proposed building roof 1,591 sq. Ft (0.037 acre) Proposed drive/walkways 788 sq. Ft (0.018 acre) Total Impervious Area 2,379 sq. Ft (0.055 acre) Target Impervious Surface = 2,379 sq. Ft (0.055 acre) Target Impervious Surface of lot = 42.6% Proposed new impervious area in ROW Proposed walkways 1,002 sq. Ft (0.023 acre) The project triggers for Simplified Drainage Review as single-family residential project that will result in 2,000 sq ft or more of new plus replaced impervious surfaced. But due to regulated slopes within the northeast portion of the site needs Targeted Drainage review per 1.1.2.2 of the 2022 Renton SWDM (per Figure 1.1.2.A of the 2022 CORSWDM below). Targeted Drainage review involves engineering analysis to mitigate erosion and sediment controls (ESC) to minimize the discharge of sediment-laden runoff during construction from the regulated slopes. As per Table C.1.1.A, question no 8, the geotechnical analysis for the site is attached and as per engineering analysis, the regulated slopes within the northeast portion of the site won’t be disturbed and there is no concentrated flow over the slopes. Effective Engineering (EE2022-63) Technical Information Report Page 6 SB INDEX SFR LLC Renton, Washington The project subject to Simplified Drainage Review must comply with the following two basic mitigation requirements in this appendix: 1. Apply on-site BMPs to developed surfaces as directed in Section C.1.3, and 2. Apply erosion and sediment control (ESC) measures to disturbed areas during construction and applicable stormwater pollution prevention and spill control (SWPPS) measures as directed in Section C.1.4. of 2022 CORSWDM. As per Geotechnical Report, the site is near the contacts between Vashon Glacial till and Vashon Recessional Outwash soils. Vashon Glacial Till includes dense mixtures of silt, sand, gravel, and clay. These deposits are typically impermeable below a weathered zone. The Vashon Recessional Outwash includes fine to medium grained sand with gravel. These deposits are typically permeable. Site consists of 6” topsoil underlain by approximately 4 feet of loose to medium dense, silty-fine to medium grained sand with gravel (Weathered Outwash?). Further, materials were underlain by medium dense, fine to medium grained gravel with sand and silt trace cobbles (Recessional Outwash). See attached geotechnical report. As per C.1.3 of 2022 CORSWDM, feasibility of all applicable BMPs is examined, most of the full/limited dispersion and infiltration BMPs are not feasible because of steep slopes and very small lot with very limited space left for drainage utilities. As per C2.11, a perforated pipe connection will be installed to drain the stormwater from new added impervious surfaces. In addition to Simplified Drainage Review, the drainage plans and TIR report are prepared by professional civil engineer to meet the Targeted Drainage Review requirements. There are not any concentrated flow over the regulated slopes, no need of flow controls from the regulated slopes. Effective Engineering (EE2022-63) Technical Information Report Page 7 SB INDEX SFR LLC Renton, Washington Effective Engineering (EE2022-63) Technical Information Report Page 8 SB INDEX SFR LLC Renton, Washington FIGURE 1 TIR WORKSHEET TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Don Bora 206-859-3094 Ben Anstey, PE Effective Engineering PLLC (206) 303-7639 Single-Family Residence ------- 23 South 05 West 9 2900 NE 5th PL, Renton, WA 98056 X X X X Mar 20, 2023 X Oct 25, 2022 Effective Engineering (EE2022-63) Technical Information Report Page 9 SB INDEX SFR LLC Renton, Washington N/A Summer 2023 Fall 2023 ---------- NA East Lake Washington - Renton Simplified Stormwater drainage review X Regulated Slopes Effective Engineering (EE2022-63) Technical Information Report Page 10 SB INDEX SFR LLC Renton, Washington Vashon Glacial Till /Vashon Recessional Outwash 15-28% Moderate X COR regulated slopes None 1 07/05/2022 Perforated Pipe connection N/A N/A N/A N/A Effective Engineering (EE2022-63) Technical Information Report Page 11 SB INDEX SFR LLC Renton, Washington N/A N/A N/A None Effective Engineering (EE2022-63) Technical Information Report Page 12 SB INDEX SFR LLC Renton, Washington X X X X X X X X X X X X X X X X X Perforated Pipe X Effective Engineering (EE2022-63) Technical Information Report Page 13 SB INDEX SFR LLC Renton, Washington March 03, 2023 Effective Engineering (EE2022-63) Technical Information Report Page 14 SB INDEX SFR LLC Renton, Washington FIGURE 2 SITE LOCATION Effective Engineering (EE2022-63) Technical Information Report Page 15 SB INDEX SFR LLC Renton, Washington FIGURE 3 DRAINAGE BASINS, SUBBASINS AND SITE CHARACTERISTICS Effective Engineering (EE2022-63) Technical Information Report Page 16 SB INDEX SFR LLC Renton, Washington FIGURE 4 SOILS SITE Effective Engineering (EE2022-63) Technical Information Report Page 17 SB INDEX SFR LLC Renton, Washington SECTION II CONDITIONS AND REQUIREMENTS SUMMARY The project must comply with all nine core requirements in Section 1.2 and all six special requirements in Section 1.3 • Core Requirement #1: Discharge at Natural Location Per 1.2.1, all storm water runoff and surface water from a project must be discharged at the natural location so as not to be diverted onto or away from d ownstream properties. The flows on this site after development will be routed through perforated pipe connected to connect to catch basin at south east at corner and finally to stormwater drainage system under Index Ave, same natural location as it is draining now under predevelopment conditions. • Core Requirement #2: Offsite Analysis Per 1.2.2, the primary component of an offsite analysis report is the downstream analysis, which examines the drainage system within one-quarter mile dow nstream of the project site or farther as described in Section 1.2.2.1: Each project subm ittal must include at least a Level 1 downstream analysis. This is an urban area and the properties around are small and fully developed. There are no significant on or off-site flows on this property. No downstream drainage problems were observed. This existing site runoff drains to the piped drainage systems in Index Ave, a closed pipe system. There is no over surface flows outside the site due to runoff from site. See Level One Downstream Analysis in section 3. • Core Requirement #3: Flow Control Facilities Per 1.2.3.1 Projects subject to Core Requirement #3 must provide fl ow control facilities as specified by the area-specific facility requirements. The project is exempt from flow control as the project is required to meet Simplified drainage review requirements listed in section C.1.3; all feasible BMPs. The perforated pipe connection will be implemented for runoff from new added impervious areas, no further need for flow control facilities. • Core Requirement #4: Conveyance System Per 1.2.4, the proposed projects are analyzed, designed, and constructed to provide a minimum level of protection against overtopping, flooding, erosion, and structural failure as specified per “Conveyance Requirements for Existing System s,” Section 1.2.4.2 Not applicable Effective Engineering (EE2022-63) Technical Information Report Page 18 SB INDEX SFR LLC Renton, Washington • Core Requirement #5: Construction Stormwater Pollution Prevention Per 1.2.5, all proposed projects that will clear, grade , or otherwise disturb the site must provide erosion and sediment controls to prevent, to the maximum extent practicable, the transport of sediment from the project site to downstre am drainage facilities, water resources, and adjacent properties. To prevent sediment transport and pollutant discharges as well as other impacts related to land-disturbing and constr uction activities, Erosion and Sediment Control (ESC) measures and Stormwater Pollution Prevention and Spill Control (SWPPS) measures that are appropriate to the project sit e must be applied through a comprehensive Construction Stormwater Pollution Preventio n (CSWPP) plan as described in Sections 1.2.5.1 and 1.2.5.3 and shall perform as describ ed in Section 1.2.5.2. Temporary ESC measures will be required as there will be disturbance of the soil to construct the new building, driveway, frontage improvement and clearing of the site. All of the flows from the site will flow onto west and south of the lot so no adjacent properties will be affected. A construction entrance and BMPs to trap the sediments on site and to avoid entering the city drainage system under Index Ave and 5th PL should be provided. Not any other special requirements are needed. In order to prevent erosion and trap sediment within the project site, the following BMPs will be used approximately as shown on the ESC plan: • Clearing limits will be marked by fencing or other means on the ground. • Extra excavated soil will be removed from the site. • A construction entrance will be placed at the location of the driveway throughout construction. • Runoff will not be allowed to concentrate and no water will be allowed to point discharge. • Mulch will be spread over all cleared areas of the site when they are not being worked. Mulch will consist of air-dried straw and chipped vegetation. • Silt fence will be installed to trap the sediments on site • Existing Catch basin in Index Ave and 5th PL will be protected using BMPs See Section VIII for details. • Core Requirement #6: Maintenance & Operations Per 1.2.6, maintenance and operation of all drainage facilities is the responsibility of the applicant or property owner, except those facilities fo r which the City assumes maintenance and operation as described below and in RMC 4-6-030.M. Drainag e facilities must be maintained and operated in accordance with the maintenance standar ds in Appendix A of this Manual, or other maintenance standards as approved by the City. The property owner will be responsible for this little maintenance and any other maintenance of installed BMPs on site. See attached Maintenance requirements. Effective Engineering (EE2022-63) Technical Information Report Page 19 SB INDEX SFR LLC Renton, Washington • Core Requirement #7: Financial Guarantees & Liability Per 1.2.7, In accordance with RMC 4-6-030, CED shall requi re all persons constructing any surface water facilities (including flow control/water qual ity facilities, conveyance systems, erosion control, and road drainage), to post with the City of Renton a bond, assignment of funds or certified check. The applicant must also maintain liability insurance as des cribed in this Core Requirement #7 The property owner will be responsible for any liability insurance, and the owner ensures that the project is constructed to the approved plans and that the drainage does not cause any problems. See Section IX for details. • Core Requirement #8: Water Quality Facilities Per 1.2.8, all proposed projects, including redevelopment projects, must provide water quality (WQ) facilities to treat the runoff from those new and r eplaced pollution-generating impervious surfaces and new pollution-generating pervious surfaces targeted for treatment as specified in the following sections. These facilities shall be selected from a menu of water quality facility options specified by the area-specific facility requirements in Section 1.2.8.1 and implemented according to the applicable WQ implementatio n requirements in Section 1.2.8.2. Not applicable. • Core Requirement #9: On-site BMPs Per 1.2.9, on-site BMPs must be selected and applied acco rding to the basic requirements, procedures, and provisions detailed in this section and the design specifications for each BMP in Appendix C, Section C.2. The project is required to provide on-site BMPs to mitigate the impacts of storm and surface water runoff generated by new impervious surface and building roofs targeted for mitigation. The project is on a site that is less than 22,000sf; it has been determined, using the order of preference outlined in Section 1.2.9.2.2, Small Lot BMP Requirements of the 2022 Renton SWDM are applicable, and that Storm water Detention is the only feasible option to meet the on-site flow control requirements as no BMPs are feasible. See discussion below: C.2.1 Full Dispersion –A 100-foot vegetated/forest flow path is not available; therefore, full dispersion is not feasible. C.2.2 Full Infiltration – However geotechnical report suggested infiltration for the added impervious surfaces but the full infiltration is not feasible due to steep slopes on site and limited space for the utilities. C.2.3 Limited Infiltration – However geotechnical report suggested infiltration for the added impervious surfaces but the full infiltration is not feasible due to steep slopes on site and limited space for the utilities. The infiltration facility (Dry well or Trench) need minimum 15’ Effective Engineering (EE2022-63) Technical Information Report Page 20 SB INDEX SFR LLC Renton, Washington from the building and 5’ from the property line. There is no enough space to fit the infiltration facility after setbacks. Sidewalk slopes toward planter strip, 5’ width of walkway runoff disperse and infiltrate over the 12’ to 8’ wide planter strip. C.2.4 Basic Dispersion – Basin dispersion is not feasible as minimum 50 feet required vegetated flow path to implement splash blocks and rock pads and 25 feet required flow path for dispersion trenches is not practical. The lot also has steep slopes. On south side portion of site, there is NO available 25’ vegetated path with 2’-6” wide dispersion trench after 5’ setback from the structure. South side also has 25%-30% slope. C.2.6 Bioretention – Not feasible due to steep slopes on site. C.2.7 Permeable Pavement – Permeable Pavement is not feasible due to steep slopes on site. C.2.11 Perforated Pipe Connection – As all BMPs above lister are not feasible, a Perforated Pipe connection will be applied for run off from new roof and driveway. A 2' x 10' Level Trench w/Perforated Pipe will be installed as per Fig C2.11.A. Special Requirements: • Special Requirement #1: Other Adopted Area-Specific Requirements, section 1.3.1 None known. • Special Requirement #2: Flood Hazard Area Delineation, section 1.3.2 Site is not in a flood plain. • Special Requirement #3: Flood Protection Facilities, section 1.3.3 No flood protection facilities are required. • Special Requirement #4: Source Control, section 1.3.4 Not applicable. • Special Requirement #5: Oil Control, section 1.3.5 Not applicable. • Special Requirement #6: Aquifer Protection Areas, section 1.3.6 This site is not in an aquifer protection area. Effective Engineering (EE2022-63) Technical Information Report Page 21 SB INDEX SFR LLC Renton, Washington SECTION III OFFSITE ANALYSIS Level One Downstream Analysis Task 1: Define and map the study area The properties to the north and east of this site have single-family residences which are fully developed and do not discharge any amount of runoff onto and from the site.; Index Ave NE is on the west and NE 5th PL on the South, the site is slopes toward Index Ave NE and NE 5th PL. The runoff from site flows to the catch basin located at south west corner of property which connected to city storm drainage system. The city drainage system from the area flow from east to west under NE 5th PL. Task 2: Review all available information on the study area Using the City of Renton iMap interactive tool, it was found that there are no immediate critical areas upstream or downstream of the property except small regulated steep slopes at north east portion of the lot. Task 3: Field Inspect the study area There are no reported problems to be investigated. There will not be any destruction of aquatic habitat on-site or downstream. The site was visited on Aug 05, 2022 and a 1/4-mile downstream investigation was made. There are no signs of surface flow and no problems were identified. The piped drainage systems flow east to west under NE 5th PL from the catch basin at south west corner of the site. There is no sign of any flows from upstream to onto identified regulated slopes on north east portion of the site. Task 4: Describe the drainage system, and its existing and predicted drainage and water quality problems For existing conditions, the site flows to catch basin at south west corner of the site, then flows toward west under NE 5th PL. The stormwater flows to city drainage system, a closed pipe system. There are no surface flows except on site to the catch basin. A quarter mile downstream inspection was performed. The inspection concluded no visual impacts or potential problems will occur from the development of the subject site. After development site will add/replaced targeted 2,379 Sq ft of impervious surface on site and 1002 sf on ROW for frontage improvement. After development, the stormwater from added/replaced impervious on site is routed through the perforated pipe to city drainage system. The stormwater partially will infiltrate on site and overflow will flow to city drainage system. There are no other significant on or off-site flows. The existing site drains to catch basins and drainage system under NE 5th PL and after development will drain to same natural location. See Figure 7 for storm drainage system. Task 5: Mitigation of Existing or Potential Problems There are no known existing or potential drainage problems and / or water quality problems. Effective Engineering (EE2022-63) Technical Information Report Page 22 SB INDEX SFR LLC Renton, Washington FIGURE 5 Sensitive Area Map Effective Engineering (EE2022-63) Technical Information Report Page 23 SB INDEX SFR LLC Renton, Washington FIGURE 6 Utilities Map Effective Engineering (EE2022-63) Technical Information Report Page 24 SB INDEX SFR LLC Renton, Washington SECTION IV FLOW CONTROL, LOW IMPACT DEVELOPMENT (LID) AND WATER QUALITY FACILITY ANALYSIS AND DESIGN Existing Site Hydrology The site has no existing development except a concrete driveway extending to 2906 NE 5th Place. The rest of site is covered with grass. The existing drive will be demolished. The site has 15% to 28% steep slopes east to west and drains toward Index Avenue to the catch basin on the corner of intersection, continue as it does in city drainage system. The site does not receive any significant off-site flows from the adjacent properties. As per Geotechnical Report, the site is near the contacts between Vashon Glacial till and Vashon Recessional Outwash soils. Vashon Glacial Till includes dense mixtures of silt, sand, gravel, and clay. These deposits are typically impermeable below a weathered zone. The Vashon Recessional Outwash includes fine to medium grained sand with gravel. These deposits are typically permeable. Site consists of 6” topsoil underlain by approximately 4 feet of loose to medium dense, silty-fine to medium grained sand with gravel (Weathered Outwash?). Further, materials were underlain by medium dense, fine to medium grained gravel with sand and silt trace cobbles (Recessional Outwash). There no evidence of any existing erosion on site. Also see attached Geotech Report. The existing land cover is modeled as 0.111 acres of B, Lawn, Steep and 0.017 acers of impervious area in WWHM; total 0.128-acre basin area. Developed Site Hydrology The proposed project will add new/replaced 2,319 sq ft of impervious surface, 1,351 sf of building roof, and 968 sf driveway and walkways; the remaining 3,262 sq ft will be landscaping. A retaining wall is proposed in the back yard of house; to retain the regulated slope. Front yard will have 15%-22% slopes. The developed land cover is modeled in WWHM as 0.073 acres of B, Steep Lawn; and 0.037 acres of Roof Tops, Flat, 0.018 acres of driveway and walks; a total of 0.055 acres of impervious area. Performance Standards The project is required to implement the Simplified Drainage review requirements as per appendix C of 2022 CORSWDM. C.2.1 Full Dispersion –A 100-foot vegetated/forest flow path is not available; therefore, full dispersion is not feasible. C.2.2 Full Infiltration – However geotechnical report suggested infiltration for the added impervious surfaces but the full infiltration is not feasible due to steep slopes on site and limited space for the utilities. Effective Engineering (EE2022-63) Technical Information Report Page 25 SB INDEX SFR LLC Renton, Washington C.2.3 Limited Infiltration – However geotechnical report suggested infiltration for the added impervious surfaces but the full infiltration is not feasible due to steep slopes on site and limited space for the utilities. C.2.4 Basic Dispersion – Basin dispersion is not feasible as minimum 50 feet required vegetated flow path to implement splash blocks and rock pads and 25 feet required flow path for dispersion trenches is not practical. The site also has steep slopes. C.2.6 Bioretention – Not feasible due to steep slopes on site. C.2.7 Permeable Pavement – Permeable Pavement is not feasible due to steep slopes on site. C.2.11 Perforated Pipe Connection – As all BMPs above lister are not feasible, a Perforated Pipe connection will be applied for run off from new roof and driveway. A 2' x 10' Level Trench w/Perforated Pipe will be installed as per Fig C2.11.A. Flow Control System Not applicable Water Quality System Not applicable SECTION V CONVEYANCE SYSTEM ANALYSIS AND DESIGN (Per Chapter 4) Not applicable SECTION VI SPECIAL REPORTS AND STUDIES A geotechnical report is attached here. SECTION VII OTHER PERMITS (Per 2.2.5) A building permit will be required. Effective Engineering (EE2022-63) Technical Information Report Page 26 SB INDEX SFR LLC Renton, Washington SECTION VIII CSWPP PLAN ANALYSIS AND DESIGN ESC Plan Analysis and Design The Erosion Control and Sedimentation Control Design will be implemented as per Appendix D of 2022 CORSWDM. Temporary ESC measures will be required as there will be disturbance of the soil to construct the walkway, driveway, and house. A silt fence and a rock construction entrance should be provided at a minimum. No special requirements are needed. See in the Appendix of this report. 1. Clearing Limits Clearing limits will be marked by fencing or other means on the ground. 2. Cover Measures Mulch will be spread over all cleared areas of the site when they are not being worked. Mulch will consist of air-dried straw and chipped vegetation. Extra excavated material will be removed from the site or spread on site. Straw Wattles will be installed on steep slopes. 3. Perimeter Protection Perimeter protection to filter sediment from sheet flow shall be provided downstream of all disturbed areas prior to upslope grading. Silt fence will be installed around the disturbed area. 4. Traffic Area Stabilization A rocked construction entrance will be placed at the location of the driveway throughout construction. 5. Sediment Retention Sediments will be retained by installing the silt fence around the site, silt fence shall be installed prior to grading any contributing area. 6. Surface Water Collection Runoff will not be allowed to concentrate and no water will be allowed to point discharge. 7. Dewatering Control It is small site; no dewatering is involved. But if needed, the water resulting from de-watering activities must be treated prior to discharge. 8. Dust Control Preventative measures shall be implemented to minimize dust. 9. Flow Control Surface water from disturbed areas must be routed through the project's onsite flow control facility. Effective Engineering (EE2022-63) Technical Information Report Page 27 SB INDEX SFR LLC Renton, Washington 10. Control Pollutants Construction activities that could contribute pollutants to surface water include the following: a. Storage and use of chemicals Utilize source control and follow erosion control plan. Use chemicals appropriately. Set up areas for proper disposal of excess materials. b. Material delivery and storage Locate temporary storage areas away from traffic and storm drains. Supply MSDS for all materials stored. Maintenance and repair of vehicles should be conducted using proper spill prevention measures. c. Building demolition Use catch basin inserts to protect drainage system from sediment. Sidewalks, streets and gutters should be swept daily. d. Saw-cutting Slurry and cuttings should be vacuumed during the activity, and must not be allowed to remain overnight. Dispose of waste material in appropriate manner. 11. Protect Existing and Proposed Stormwater Facilities and On-site BMPs There are no existing BMPs on site. Protection measures shall be applied/installed and maintained so as to prevent adverse impacts to the areas of proposed stormwater facilities and on-site BMPs for the project. 12. Maintain Protective BMP Protection measures shall be maintained to ensure continued performance of their intended function, to prevent adverse impacts to existing BMPs/facilities and areas of proposed BMPs/facilities, and protect other disturbed areas of the project. 13. Manage the Project Coordination and timing of site development activities relative to ESC concerns, and timely inspection, maintenance and update of protective measures are necessary to effectively manage the project and ensure the success of protective ESC and SWPPS design and implementation. SECTION IX BOND QUANTITIES, FACILITY SUMMARIES AND DECLARATION OF COVENANT Per section 1.2.7, 2017 City of Renton Surface Water De sign Manual Bond Quantities Worksheet See attached. Flow Control and Water Quality Facility Summary Sheet a nd Sketch Not applicable Effective Engineering (EE2022-63) Technical Information Report Page 28 SB INDEX SFR LLC Renton, Washington SECTION X OPERATIONS AND MAINTENANCE MANUAL Owner will be responsible for maintenance, on-site catch basins and Perforated Pipe connection Facilities. Effective Engineering (EE2022-63) Technical Information Report Page 29 SB INDEX SFR LLC Renton, Washington Effective Engineering (EE2022-63) Technical Information Report Page 30 SB INDEX SFR LLC Renton, Washington Effective Engineering (EE2022-63) Technical Information Report Page 31 SB INDEX SFR LLC Renton, Washington APPENDIX: BMPS Effective Engineering (EE2022-63) Technical Information Report Page 32 SB INDEX SFR LLC Renton, Washington WWHM2012 PROJECT REPORT EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:11 PM Page 2 General Model Information Project Name: EE2022-63 - 2900 NE 5TH PL RENTON Site Name: SFR RESIDENCE Site Address: 2900 NE 5TH PL City: RENTON Report Date: 10/23/2022 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 EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:11 PM Page 3 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass: No GroundWater: No Pervious Land Use acre A B, Lawn, Steep 0.111 Pervious Total 0.111 Impervious Land Use acre DRIVEWAYS STEEP 0.017 Impervious Total 0.017 Basin Total 0.128 Element Flows To: Surface Interflow Groundwater EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:12 PM Page 4 Mitigated Land Use Basin 1 Bypass: No GroundWater: No Pervious Land Use acre A B, Lawn, Steep 0.075 Pervious Total 0.075 Impervious Land Use acre ROADS FLAT 0.031 DRIVEWAYS MOD 0.022 Impervious Total 0.053 Basin Total 0.128 Element Flows To: Surface Interflow Groundwater EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:12 PM Page 5 Routing Elements Predeveloped Routing EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:12 PM Page 6 Mitigated Routing EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:12 PM Page 7 Analysis Results POC 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area: 0.111 Total Impervious Area: 0.017 Mitigated Landuse Totals for POC #1 Total Pervious Area: 0.075 Total Impervious Area: 0.053 Flow Frequency Method: Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.009532 5 year 0.014563 10 year 0.018774 25 year 0.025252 50 year 0.031025 100 year 0.037707 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.022172 5 year 0.0293 10 year 0.034524 25 year 0.04172 50 year 0.047529 100 year 0.053737 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.011 0.028 1950 0.022 0.032 1951 0.011 0.020 1952 0.006 0.015 1953 0.006 0.017 1954 0.010 0.019 1955 0.007 0.020 1956 0.014 0.019 1957 0.007 0.021 1958 0.006 0.018 EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:48 PM Page 8 1959 0.007 0.019 1960 0.011 0.019 1961 0.009 0.018 1962 0.006 0.016 1963 0.008 0.019 1964 0.010 0.018 1965 0.011 0.023 1966 0.006 0.015 1967 0.021 0.032 1968 0.012 0.031 1969 0.008 0.020 1970 0.007 0.020 1971 0.009 0.024 1972 0.017 0.030 1973 0.006 0.015 1974 0.009 0.022 1975 0.009 0.025 1976 0.009 0.018 1977 0.007 0.018 1978 0.010 0.024 1979 0.012 0.031 1980 0.013 0.030 1981 0.008 0.022 1982 0.011 0.031 1983 0.009 0.025 1984 0.007 0.016 1985 0.008 0.021 1986 0.007 0.019 1987 0.010 0.029 1988 0.007 0.018 1989 0.011 0.026 1990 0.039 0.055 1991 0.021 0.037 1992 0.006 0.016 1993 0.008 0.016 1994 0.007 0.016 1995 0.008 0.019 1996 0.024 0.031 1997 0.011 0.023 1998 0.008 0.021 1999 0.027 0.043 2000 0.007 0.021 2001 0.009 0.024 2002 0.010 0.026 2003 0.011 0.024 2004 0.016 0.041 2005 0.006 0.017 2006 0.009 0.018 2007 0.044 0.055 2008 0.025 0.036 2009 0.012 0.029 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0439 0.0551 2 0.0394 0.0550 3 0.0272 0.0430 EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:48 PM Page 9 4 0.0251 0.0410 5 0.0237 0.0369 6 0.0216 0.0357 7 0.0213 0.0319 8 0.0205 0.0316 9 0.0169 0.0314 10 0.0157 0.0313 11 0.0137 0.0308 12 0.0133 0.0307 13 0.0125 0.0297 14 0.0120 0.0296 15 0.0117 0.0291 16 0.0113 0.0288 17 0.0111 0.0283 18 0.0111 0.0257 19 0.0110 0.0257 20 0.0108 0.0253 21 0.0108 0.0246 22 0.0108 0.0243 23 0.0105 0.0241 24 0.0105 0.0240 25 0.0102 0.0240 26 0.0099 0.0229 27 0.0098 0.0227 28 0.0096 0.0221 29 0.0092 0.0217 30 0.0091 0.0214 31 0.0091 0.0212 32 0.0090 0.0209 33 0.0088 0.0206 34 0.0087 0.0204 35 0.0086 0.0203 36 0.0086 0.0200 37 0.0083 0.0199 38 0.0079 0.0194 39 0.0077 0.0193 40 0.0077 0.0193 41 0.0076 0.0188 42 0.0075 0.0188 43 0.0075 0.0187 44 0.0075 0.0187 45 0.0074 0.0183 46 0.0074 0.0182 47 0.0072 0.0182 48 0.0071 0.0179 49 0.0071 0.0178 50 0.0070 0.0178 51 0.0067 0.0177 52 0.0065 0.0174 53 0.0065 0.0168 54 0.0063 0.0164 55 0.0063 0.0161 56 0.0063 0.0158 57 0.0062 0.0156 58 0.0060 0.0155 59 0.0057 0.0153 60 0.0057 0.0151 61 0.0055 0.0146 EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:48 PM Page 10 EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:48 PM Page 11 Duration Flows Flow(cfs) Predev Mit Percentage Pass/Fail 0.0048 930 15736 1692 Fail 0.0050 777 13995 1801 Fail 0.0053 663 12502 1885 Fail 0.0056 587 11171 1903 Fail 0.0058 499 10004 2004 Fail 0.0061 443 8932 2016 Fail 0.0064 387 7989 2064 Fail 0.0066 339 7197 2123 Fail 0.0069 297 6462 2175 Fail 0.0072 271 5876 2168 Fail 0.0074 239 5270 2205 Fail 0.0077 215 4806 2235 Fail 0.0079 195 4348 2229 Fail 0.0082 168 3942 2346 Fail 0.0085 145 3583 2471 Fail 0.0087 133 3277 2463 Fail 0.0090 117 3009 2571 Fail 0.0093 102 2725 2671 Fail 0.0095 99 2468 2492 Fail 0.0098 91 2265 2489 Fail 0.0101 78 2071 2655 Fail 0.0103 71 1906 2684 Fail 0.0106 68 1750 2573 Fail 0.0109 60 1606 2676 Fail 0.0111 55 1487 2703 Fail 0.0114 52 1368 2630 Fail 0.0117 50 1254 2508 Fail 0.0119 48 1170 2437 Fail 0.0122 46 1073 2332 Fail 0.0125 43 1000 2325 Fail 0.0127 39 919 2356 Fail 0.0130 38 860 2263 Fail 0.0133 38 787 2071 Fail 0.0135 35 724 2068 Fail 0.0138 33 683 2069 Fail 0.0140 31 633 2041 Fail 0.0143 29 584 2013 Fail 0.0146 28 548 1957 Fail 0.0148 26 511 1965 Fail 0.0151 26 488 1876 Fail 0.0154 26 464 1784 Fail 0.0156 24 432 1800 Fail 0.0159 22 417 1895 Fail 0.0162 22 397 1804 Fail 0.0164 22 373 1695 Fail 0.0167 22 349 1586 Fail 0.0170 19 333 1752 Fail 0.0172 19 314 1652 Fail 0.0175 19 296 1557 Fail 0.0178 19 282 1484 Fail 0.0180 19 268 1410 Fail 0.0183 18 249 1383 Fail 0.0186 18 233 1294 Fail 0.0188 17 210 1235 Fail EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:48 PM Page 12 0.0191 17 201 1182 Fail 0.0194 16 183 1143 Fail 0.0196 15 178 1186 Fail 0.0199 15 168 1120 Fail 0.0202 14 160 1142 Fail 0.0204 14 152 1085 Fail 0.0207 13 142 1092 Fail 0.0209 13 133 1023 Fail 0.0212 11 127 1154 Fail 0.0215 9 124 1377 Fail 0.0217 8 120 1500 Fail 0.0220 8 114 1425 Fail 0.0223 8 110 1375 Fail 0.0225 8 107 1337 Fail 0.0228 8 99 1237 Fail 0.0231 8 95 1187 Fail 0.0233 8 92 1150 Fail 0.0236 8 90 1125 Fail 0.0239 7 85 1214 Fail 0.0241 7 80 1142 Fail 0.0244 7 77 1100 Fail 0.0247 7 70 1000 Fail 0.0249 7 68 971 Fail 0.0252 5 66 1320 Fail 0.0255 5 62 1240 Fail 0.0257 5 58 1160 Fail 0.0260 5 55 1100 Fail 0.0263 5 52 1040 Fail 0.0265 5 52 1040 Fail 0.0268 5 49 980 Fail 0.0270 5 48 960 Fail 0.0273 4 47 1175 Fail 0.0276 4 45 1125 Fail 0.0278 4 43 1075 Fail 0.0281 4 42 1050 Fail 0.0284 4 39 975 Fail 0.0286 4 36 900 Fail 0.0289 4 34 850 Fail 0.0292 4 30 750 Fail 0.0294 4 30 750 Fail 0.0297 4 28 700 Fail 0.0300 4 27 675 Fail 0.0302 4 26 650 Fail 0.0305 4 26 650 Fail 0.0308 4 25 625 Fail 0.0310 4 23 575 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. EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:48 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. EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:48 PM Page 14 LID Report EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:59 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. EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:59 PM Page 16 Appendix Predeveloped Schematic EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:55:59 PM Page 17 Mitigated Schematic EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:56:01 PM Page 18 Predeveloped UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 EE2022-63 - 2900 NE 5TH PL RENTON.wdm MESSU 25 PreEE2022-63 - 2900 NE 5TH PL RENTON.MES 27 PreEE2022-63 - 2900 NE 5TH PL RENTON.L61 28 PreEE2022-63 - 2900 NE 5TH PL RENTON.L62 30 POCEE2022-63 - 2900 NE 5TH PL RENTON1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 9 IMPLND 7 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 9 A/B, Lawn, Steep 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 9 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 9 0 0 4 0 0 0 0 0 0 0 0 0 1 9 END PRINT-INFO EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:56:01 PM Page 19 PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 9 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 9 0 5 0.8 400 0.15 0.3 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 9 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 9 0.1 0.5 0.25 0 0.7 0.25 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 9 0 0 0 0 3 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 7 DRIVEWAYS/STEEP 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 7 0 0 1 0 0 0 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 7 0 0 4 0 0 0 1 9 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 7 0 0 0 0 0 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 7 400 0.1 0.1 0.05 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 7 0 0 EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:56:01 PM Page 20 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 7 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1*** PERLND 9 0.111 COPY 501 12 PERLND 9 0.111 COPY 501 13 IMPLND 7 0.017 COPY 501 15 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:56:01 PM Page 21 END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 501 OUTPUT MEAN 1 1 48.4 WDM 501 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 END MASS-LINK END RUN EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:56:01 PM Page 22 Mitigated UCI File RUN GLOBAL WWHM4 model simulation START 1948 10 01 END 2009 09 30 RUN INTERP OUTPUT LEVEL 3 0 RESUME 0 RUN 1 UNIT SYSTEM 1 END GLOBAL FILES <File> <Un#> <-----------File Name------------------------------>*** <-ID-> *** WDM 26 EE2022-63 - 2900 NE 5TH PL RENTON.wdm MESSU 25 MitEE2022-63 - 2900 NE 5TH PL RENTON.MES 27 MitEE2022-63 - 2900 NE 5TH PL RENTON.L61 28 MitEE2022-63 - 2900 NE 5TH PL RENTON.L62 30 POCEE2022-63 - 2900 NE 5TH PL RENTON1.dat END FILES OPN SEQUENCE INGRP INDELT 00:15 PERLND 9 IMPLND 1 IMPLND 6 COPY 501 DISPLY 1 END INGRP END OPN SEQUENCE DISPLY DISPLY-INFO1 # - #<----------Title----------->***TRAN PIVL DIG1 FIL1 PYR DIG2 FIL2 YRND 1 Basin 1 MAX 1 2 30 9 END DISPLY-INFO1 END DISPLY COPY TIMESERIES # - # NPT NMN *** 1 1 1 501 1 1 END TIMESERIES END COPY GENER OPCODE # # OPCD *** END OPCODE PARM # # K *** END PARM END GENER PERLND GEN-INFO <PLS ><-------Name------->NBLKS Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 9 A/B, Lawn, Steep 1 1 1 1 27 0 END GEN-INFO *** Section PWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC *** 9 0 0 1 0 0 0 0 0 0 0 0 0 END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ***************************** PIVL PYR # - # ATMP SNOW PWAT SED PST PWG PQAL MSTL PEST NITR PHOS TRAC ********* 9 0 0 4 0 0 0 0 0 0 0 0 0 1 9 EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:56:01 PM Page 23 END PRINT-INFO PWAT-PARM1 <PLS > PWATER variable monthly parameter value flags *** # - # CSNO RTOP UZFG VCS VUZ VNN VIFW VIRC VLE INFC HWT *** 9 0 0 0 0 0 0 0 0 0 0 0 END PWAT-PARM1 PWAT-PARM2 <PLS > PWATER input info: Part 2 *** # - # ***FOREST LZSN INFILT LSUR SLSUR KVARY AGWRC 9 0 5 0.8 400 0.15 0.3 0.996 END PWAT-PARM2 PWAT-PARM3 <PLS > PWATER input info: Part 3 *** # - # ***PETMAX PETMIN INFEXP INFILD DEEPFR BASETP AGWETP 9 0 0 2 2 0 0 0 END PWAT-PARM3 PWAT-PARM4 <PLS > PWATER input info: Part 4 *** # - # CEPSC UZSN NSUR INTFW IRC LZETP *** 9 0.1 0.5 0.25 0 0.7 0.25 END PWAT-PARM4 PWAT-STATE1 <PLS > *** Initial conditions at start of simulation ran from 1990 to end of 1992 (pat 1-11-95) RUN 21 *** # - # *** CEPS SURS UZS IFWS LZS AGWS GWVS 9 0 0 0 0 3 1 0 END PWAT-STATE1 END PERLND IMPLND GEN-INFO <PLS ><-------Name-------> Unit-systems Printer *** # - # User t-series Engl Metr *** in out *** 1 ROADS/FLAT 1 1 1 27 0 6 DRIVEWAYS/MOD 1 1 1 27 0 END GEN-INFO *** Section IWATER*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # ATMP SNOW IWAT SLD IWG IQAL *** 1 0 0 1 0 0 0 6 0 0 1 0 0 0 END ACTIVITY PRINT-INFO <ILS > ******** Print-flags ******** PIVL PYR # - # ATMP SNOW IWAT SLD IWG IQAL ********* 1 0 0 4 0 0 0 1 9 6 0 0 4 0 0 0 1 9 END PRINT-INFO IWAT-PARM1 <PLS > IWATER variable monthly parameter value flags *** # - # CSNO RTOP VRS VNN RTLI *** 1 0 0 0 0 0 6 0 0 0 0 0 END IWAT-PARM1 IWAT-PARM2 <PLS > IWATER input info: Part 2 *** # - # *** LSUR SLSUR NSUR RETSC 1 400 0.01 0.1 0.1 6 400 0.05 0.1 0.08 EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:56:01 PM Page 24 END IWAT-PARM2 IWAT-PARM3 <PLS > IWATER input info: Part 3 *** # - # ***PETMAX PETMIN 1 0 0 6 0 0 END IWAT-PARM3 IWAT-STATE1 <PLS > *** Initial conditions at start of simulation # - # *** RETS SURS 1 0 0 6 0 0 END IWAT-STATE1 END IMPLND SCHEMATIC <-Source-> <--Area--> <-Target-> MBLK *** <Name> # <-factor-> <Name> # Tbl# *** Basin 1*** PERLND 9 0.075 COPY 501 12 PERLND 9 0.075 COPY 501 13 IMPLND 1 0.031 COPY 501 15 IMPLND 6 0.022 COPY 501 15 ******Routing****** END SCHEMATIC NETWORK <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** COPY 501 OUTPUT MEAN 1 1 48.4 DISPLY 1 INPUT TIMSER 1 <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # #<-factor->strg <Name> # # <Name> # # *** END NETWORK RCHRES GEN-INFO RCHRES Name Nexits Unit Systems Printer *** # - #<------------------><---> User T-series Engl Metr LKFG *** in out *** END GEN-INFO *** Section RCHRES*** ACTIVITY <PLS > ************* Active Sections ***************************** # - # HYFG ADFG CNFG HTFG SDFG GQFG OXFG NUFG PKFG PHFG *** END ACTIVITY PRINT-INFO <PLS > ***************** Print-flags ******************* PIVL PYR # - # HYDR ADCA CONS HEAT SED GQL OXRX NUTR PLNK PHCB PIVL PYR ********* END PRINT-INFO HYDR-PARM1 RCHRES Flags for each HYDR Section *** # - # VC A1 A2 A3 ODFVFG for each *** ODGTFG for each FUNCT for each FG FG FG FG possible exit *** possible exit possible exit * * * * * * * * * * * * * * *** END HYDR-PARM1 HYDR-PARM2 # - # FTABNO LEN DELTH STCOR KS DB50 *** <------><--------><--------><--------><--------><--------><--------> *** END HYDR-PARM2 EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:56:01 PM Page 25 HYDR-INIT RCHRES Initial conditions for each HYDR section *** # - # *** VOL Initial value of COLIND Initial value of OUTDGT *** ac-ft for each possible exit for each possible exit <------><--------> <---><---><---><---><---> *** <---><---><---><---><---> END HYDR-INIT END RCHRES SPEC-ACTIONS END SPEC-ACTIONS FTABLES END FTABLES EXT SOURCES <-Volume-> <Member> SsysSgap<--Mult-->Tran <-Target vols> <-Grp> <-Member-> *** <Name> # <Name> # tem strg<-factor->strg <Name> # # <Name> # # *** WDM 2 PREC ENGL 1 PERLND 1 999 EXTNL PREC WDM 2 PREC ENGL 1 IMPLND 1 999 EXTNL PREC WDM 1 EVAP ENGL 0.76 PERLND 1 999 EXTNL PETINP WDM 1 EVAP ENGL 0.76 IMPLND 1 999 EXTNL PETINP END EXT SOURCES EXT TARGETS <-Volume-> <-Grp> <-Member-><--Mult-->Tran <-Volume-> <Member> Tsys Tgap Amd *** <Name> # <Name> # #<-factor->strg <Name> # <Name> tem strg strg*** COPY 1 OUTPUT MEAN 1 1 48.4 WDM 701 FLOW ENGL REPL COPY 501 OUTPUT MEAN 1 1 48.4 WDM 801 FLOW ENGL REPL END EXT TARGETS MASS-LINK <Volume> <-Grp> <-Member-><--Mult--> <Target> <-Grp> <-Member->*** <Name> <Name> # #<-factor-> <Name> <Name> # #*** MASS-LINK 12 PERLND PWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 12 MASS-LINK 13 PERLND PWATER IFWO 0.083333 COPY INPUT MEAN END MASS-LINK 13 MASS-LINK 15 IMPLND IWATER SURO 0.083333 COPY INPUT MEAN END MASS-LINK 15 END MASS-LINK END RUN EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:56:01 PM Page 26 Predeveloped HSPF Message File EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:56:01 PM Page 27 Mitigated HSPF Message File EE2022-63 - 2900 NE 5TH PL RENTON 10/23/2022 7:56:01 PM Page 28 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. 2005-2022; 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 Cobalt Geosciences, LLC P.O. Box 82243 Kenmore, Washington 98028 www.cobaltgeo.com (206) 331-1097 February 10, 2022 Don Bora don@bluelam.com RE: Proposal for Geotechnical Evaluation Proposed Residence 29xx NE 5th Place Renton, Washington In accordance with your authorization, Cobalt Geosciences, LLC has prepared this letter to discuss the results of our geotechnical evaluation at the referenced site. The purpose of our evaluation was to provide recommendations for foundation design, grading, and earthwork. Site Description The site is located at 29xx NE 5th Place in Renton, Washington. The site consists of one irregularly shaped parcel (No. 7227800631) with a total area of 5,682 square feet. The site consists of a newly subdivided lot from 2906 NE 5th Place. The site is partially developed with a driveway extending to 2906 NE 5th Place. The remainder of the site is vegetated with grasses. The site consists of a high area with slopes extending downward to the north, west, and south at magnitudes of 10 to 50 percent and relief of about 8 feet. The site is bordered to the north and east by residences, to the west by Index Avenue NE and to the south by NE 5th Place. The proposed development includes a new residence and driveway in the central portion of the property. Stormwater will include infiltration or other systems depending on feasibility. Site grading may include cuts and fills of 6 feet or less and foundation loads are expected to be light. We should be provided with the final plans to verify that our recommendations remain valid and do not require updating. Area Geology The Geologic Map of King County, indicates that the site is near the contacts between Vashon Glacial Till and Vashon Recessional Outwash. Vashon Glacial Till includes dense mixtures of silt, sand, gravel, and clay. These deposits are typically impermeable below a weathered zone. The Vashon Recessional Outwash includes fine to medium grained sand with gravel. These deposits are typically permeable. February 10, 2022 Page 2 of 10 Geotechnical Evaluation www.cobaltgeo.com (206) 331-1097 Soil & Groundwater Conditions As part of our evaluation, we excavated one test pit where accessible. The exploration encountered approximately 6 inches of grass and topsoil underlain by approximately 4 feet of loose to medium dense, silty-fine to medium grained sand with gravel (Weathered Outwash?). These materials were underlain by medium dense, fine to medium grained gravel with sand and silt trace cobbles (Recessional Outwash), which continued to the termination depths of the exploration. Groundwater was not encountered in the exploration during our work. We do not anticipate significant groundwater to be present at this site. Water table elevations often fluctuate over time. The groundwater level will depend on a variety of factors that may include seasonal precipitation, irrigation, land use, climatic conditions and soil permeability. Water levels at the time of the field investigation may be different from those encountered during the construction phase of the project. It would be necessary to install a piezometer to determine groundwater depths over a typical year. Erosion Hazard The Natural Resources Conservation Services (NRCS) maps for King County indicate that the site is underlain by Arents, Everett material. These soils would have a slight to moderate erosion potential in a disturbed state depending on the slope magnitude. It is our opinion that soil erosion potential at this project site can be reduced through landscaping and surface water runoff control. Typically, erosion of exposed soils will be most noticeable during periods of rainfall and may be controlled by the use of normal temporary erosion control measures, such as silt fences, hay bales, mulching, control ditches and diversion trenches. The typical wet weather season, with regard to site grading, is from October 31st to April 1st. Erosion control measures should be in place before the onset of wet weather. Seismic Parameters The overall subsurface profile corresponds to a Site Class D as defined by Table 1613.5.2 of the International Building Code (IBC). A Site Class D applies to an overall profile consisting of stiff/medium dense soils within the upper 100 feet. We referenced the U.S. Geological Survey (USGS) Earthquake Hazards Program Website to obtain values for SS, S1, Fa, and Fv. The USGS website includes the most updated published data on seismic conditions. The following tables provide seismic parameters from the USGS web site with referenced parameters from ASCE 7-10 and 7-16. Seismic Design Parameters (ASCE 7-10) Site Class Spectral Acceleration at 0.2 sec. (g) Spectral Acceleration at 1.0 sec. (g) Site Coefficients Design Spectral Response Parameters Design PGA Fa Fv SDS SD1 D 1.421 0.533 1.0 1.5 0.947 0.533 0.585 February 10, 2022 Page 3 of 10 Geotechnical Evaluation www.cobaltgeo.com (206) 331-1097 Seismic Design Parameters (ASCE 7-16) Site Class Spectral Acceleration at 0.2 sec. (g) Spectral Acceleration at 1.0 sec. (g) Site Coefficients Design Spectral Response Parameters Design PGA Fa Fv SDS SD1 D 1.421 0.486 1.0 Null 0.947 Null 0.605 Additional seismic considerations include liquefaction potential and amplification of ground motions by soft/loose soil deposits. The liquefaction potential is highest for loose sand with a high groundwater table. The site has a relatively low likelihood of liquefaction. For items listed as “Null” see Section 11.4.8 of the ASCE. Conclusions and Recommendations General The site is underlain by soils consistent with Vashon Recessional Outwash. These soils become somewhat dense below a weathered zone. The proposed residential structure may be supported on a shallow foundation system bearing on medium dense or firmer native soils or on structural fill placed on the native soils. Local overexcavation or recompaction of loose weathered native soils may be necessary depending on the proposed elevations and locations of the new footings. Note that the upper fine-grained soils were locally loose and may require removal in foundation areas. Infiltration is feasible in the outwash sands below the fine grained soil materials. Trenches or drywells should extend at least 6 inches into the sands as verified by the geotechnical engineer during construction. The sands are consistent with Medium Sand per the King County Surface Water Design Manual. Any system must have overflow to City infrastructure since there is a chance that dense till underlies the outwash. Site Preparation Trees, shrubs and other vegetation should be removed prior to stripping of surficial organic-rich soil and fill. Based on observations from the site investigation program, it is anticipated that the stripping depth will be 6 to 18 inches. Deeper excavations will be necessary below larger trees and foundation systems. The native soils consist of silty-sand with gravel with coarser sands and gravels at depth. Most of the native soils may be used as structural fill provided they achieve compaction requirements and are within 3 percent of the optimum moisture. Some of these soils may only be suitable for use as fill during the summer months, as they will be above the optimum moisture levels in their current state. These soils are variably moisture sensitive and may degrade during periods of wet weather and under equipment traffic. February 10, 2022 Page 4 of 10 Geotechnical Evaluation www.cobaltgeo.com (206) 331-1097 Imported structural fill should consist of a sand and gravel mixture with a maximum grain size of 3 inches and less than 5 percent fines (material passing the U.S. Standard No. 200 Sieve). Structural fill should be placed in maximum lift thicknesses of 12 inches and should be compacted to a minimum of 95 percent of the modified proctor maximum dry density, as determined by the ASTM D 1557 test method. Temporary Excavations Based on our understanding of the project, we anticipate that the grading could include local cuts on the order of approximately 6 feet or less for foundation and most of the utility placement. Temporary excavations should be sloped no steeper than 1.5H:1V (Horizontal:Vertical) in loose native soils and fill and 1H:1V in medium dense native soils. If an excavation is subject to heavy vibration or surcharge loads, we recommend that the excavations be sloped no steeper than 2H:1V, where room permits. Temporary cuts should be in accordance with the Washington Administrative Code (WAC) Part N, Excavation, Trenching, and Shoring. Temporary slopes should be visually inspected daily by a qualified person during construction activities and the inspections should be documented in daily reports. The contractor is responsible for maintaining the stability of the temporary cut slopes and reducing slope erosion during construction. Temporary cut slopes should be covered with visqueen to help reduce erosion during wet weather, and the slopes should be closely monitored until the permanent retaining systems or slope configurations are complete. Materials should not be stored or equipment operated within 10 feet of the top of any temporary cut slope. Soil conditions may not be completely known from the geotechnical investigation. In the case of temporary cuts, the existing soil conditions may not be completely revealed until the excavation work exposes the soil. Typically, as excavation work progresses the maximum inclination of temporary slopes will need to be re-evaluated by the geotechnical engineer so that supplemental recommendations can be made. Soil and groundwater conditions can be highly variable. Scheduling for soil work will need to be adjustable, to deal with unanticipated conditions, so that the project can proceed and required deadlines can be met. If any variations or undesirable conditions are encountered during construction, we should be notified so that supplemental recommendations can be made. If room constraints or groundwater conditions do not permit temporary slopes to be cut to the maximum angles allowed by the WAC, temporary shoring systems may be required. The contractor should be responsible for developing temporary shoring systems, if needed. We recommend that Cobalt Geosciences and the project structural engineer review temporary shoring designs prior to installation, to verify the suitability of the proposed systems. Foundation Design The proposed structure may be supported on a shallow spread footing foundation system bearing on undisturbed dense or firmer native soils or on properly compacted structural fill placed on the suitable native soils. Any undocumented fill and/or loose native soils should be removed and replaced with structural fill below foundation elements. Structural fill below footings should consist of clean angular rock 5/8 to 4 inches in size. We should verify soil conditions during foundation excavation work. Note that the upper fine grained soils are locally loose and some overexcavation should be anticipated to be necessary. February 10, 2022 Page 5 of 10 Geotechnical Evaluation www.cobaltgeo.com (206) 331-1097 For shallow foundation support, we recommend widths of at least 16 and 24 inches, respectively, for continuous wall and isolated column footings supporting the proposed structure. Provided that the footings are supported as recommended above, a net allowable bearing pressure of 2,000 pounds per square foot (psf) may be used for design. A 1/3 increase in the above value may be used for short duration loads, such as those imposed by wind and seismic events. Structural fill placed on bearing, native subgrade should be compacted to at least 95 percent of the maximum dry density based on ASTM Test Method D1557. Footing excavations should be inspected to verify that the foundations will bear on suitable material. Exterior footings should have a minimum depth of 18 inches below pad subgrade (soil grade) or adjacent exterior grade, whichever is lower. Interior footings should have a minimum depth of 12 inches below pad subgrade (soil grade) or adjacent exterior grade, whichever is lower. If constructed as recommended, the total foundation settlement is not expected to exceed 1 inch. Differential settlement, along a 25-foot exterior wall footing, or between adjoining column footings, should be less than ½ inch. This translates to an angular distortion of 0.002. Most settlement is expected to occur during construction, as the loads are applied. However, additional post-construction settlement may occur if the foundation soils are flooded or saturated. All footing excavations should be observed by a qualified geotechnical consultant. Resistance to lateral footing displacement can be determined using an allowable friction factor of 0.40 acting between the base of foundations and the supporting subgrades. Lateral resistance for footings can also be developed using an allowable equivalent fluid passive pressure of 250 pounds per cubic foot (pcf) acting against the appropriate vertical footing faces (neglect the upper 12 inches below grade in exterior areas). The frictional and passive resistance of the soil may be combined without reduction in determining the total lateral resistance. Care should be taken to prevent wetting or drying of the bearing materials during construction. Any extremely wet or dry materials, or any loose or disturbed materials at the bottom of the footing excavations, should be removed prior to placing concrete. The potential for wetting or drying of the bearing materials can be reduced by pouring concrete as soon as possible after completing the footing excavation and evaluating the bearing surface by the geotechnical engineer or his representative. Concrete Retaining Walls The following table, titled Wall Design Criteria, presents the recommended soil related design parameters for retaining walls with a level backslope. Contact Cobalt if an alternate retaining wall system is used. This has been included for new cast in place walls, if any are proposed. Wall Design Criteria “At-rest” Conditions (Lateral Earth Pressure – EFD+) 55 pcf (Equivalent Fluid Density) “Active” Conditions (Lateral Earth Pressure – EFD+) 35 pcf (Equivalent Fluid Density) Seismic Increase for “At-rest” Conditions (Lateral Earth Pressure) 21H* (Uniform Distribution) 1 in 2,500 year event Seismic Increase for “At-rest” Conditions (Lateral Earth Pressure) 14H* (Uniform Distribution) 1 in 500 year event February 10, 2022 Page 6 of 10 Geotechnical Evaluation www.cobaltgeo.com (206) 331-1097 Seismic Increase for “Active” Conditions (Lateral Earth Pressure) 7H* (Uniform Distribution) Passive Earth Pressure on Low Side of Wall (Allowable, includes F.S. = 1.5) Neglect upper 2 feet, then 275 pcf EFD+ Soil-Footing Coefficient of Sliding Friction (Allowable; includes F.S. = 1.5) 0.40 *H is the height of the wall; Increase based on one in 500 year seismic event (10 percent probability of being exceeded in 50 years), +EFD – Equivalent Fluid Density The stated lateral earth pressures do not include the effects of hydrostatic pressure generated by water accumulation behind the retaining walls. Uniform horizontal lateral active and at-rest pressures on the retaining walls from vertical surcharges behind the wall may be calculated using active and at-rest lateral earth pressure coefficients of 0.3 and 0.5, respectively. A soil unit weight of 125 pcf may be used to calculate vertical earth surcharges. To reduce the potential for the buildup of water pressure against the walls, continuous footing drains (with cleanouts) should be provided at the bases of the walls. The footing drains should consist of a minimum 4-inch diameter perforated pipe, sloped to drain, with perforations placed down and enveloped by a minimum 6 inches of pea gravel in all directions. The backfill adjacent to and extending a lateral distance behind the walls at least 2 feet should consist of free-draining granular material. All free draining backfill should contain less than 3 percent fines (passing the U.S. Standard No. 200 Sieve) based upon the fraction passing the U.S. Standard No. 4 Sieve with at least 30 percent of the material being retained on the U.S. Standard No. 4 Sieve. The primary purpose of the free-draining material is the reduction of hydrostatic pressure. Some potential for the moisture to contact the back face of the wall may exist, even with treatment, which may require that more extensive waterproofing be specified for walls, which require interior moisture sensitive finishes. We recommend that the backfill be compacted to at least 90 percent of the maximum dry density based on ASTM Test Method D1557. In place density tests should be performed to verify adequate compaction. Soil compactors place transient surcharges on the backfill. Consequently, only light hand operated equipment is recommended within 3 feet of walls so that excessive stress is not imposed on the walls. Stormwater Management Feasibility The site is underlain by a layer of silty soils underlain by coarser outwash. We performed a small scale pilot infiltration test (PIT) in TP-1. The test was performed in general accordance with the Washington State Department of Ecology stormwater manual. The area was excavated to a testing depth of approximately 6 feet below the ground surface.. The design infiltration rate was determined by applying correction factors to the measured infiltration rate as prescribed in Volume III, Section 3.3.6 of the DOE. The measured rate must be reduced through appropriate correction factors for site variability (CFV), uncertainty of test method (CFT), and degree of influent control (CFM) to prevent siltation and bio-buildup. February 10, 2022 Page 7 of 10 Geotechnical Evaluation www.cobaltgeo.com (206) 331-1097 It should be noted that construction traffic or other disturbance to the target infiltration area could compact the soil, which may decrease the effective infiltration rates. The correction factors and resulting design infiltration rate are also shown in the table below. Test Number Test Depth (ft) Measured Infiltration Rate (in/hr) Correction Factors Design Infiltration Rate (in/hr) CFV CFT CFM TP-1 6.0 2.7 0.7 0.5 0.9 0.85 Widespread infiltration is feasible in the outwash sands below about 4.5 feet. These soils consist of sand with gravel trace to with silt. We must be on site to verify soil conditions in the trenches/drywells during construction. All trenches or drywells must penetrate into the sands at least 6 inches. The soils are consistent with Medium Sand by the King County SWDM. Systems must have overflow to City infrastructure and we recommend that systems be located lower in elevation to nearby residences. We should be provided with final plans for review to determine if the intent of our recommendations has been incorporated or if additional modifications are needed. Slab-on-Grade We recommend that the upper 18 inches of the existing native soils within slab areas be re- compacted to at least 95 percent of the modified proctor (ASTM D1557 Test Method). Often, a vapor barrier is considered below concrete slab areas. However, the usage of a vapor barrier could result in curling of the concrete slab at joints. Floor covers sensitive to moisture typically requires the usage of a vapor barrier. A materials or structural engineer should be consulted regarding the detailing of the vapor barrier below concrete slabs. Exterior slabs typically do not utilize vapor barriers. The American Concrete Institutes ACI 360R-06 Design of Slabs on Grade and ACI 302.1R-04 Guide for Concrete Floor and Slab Construction are recommended references for vapor barrier selection and floor slab detailing. Slabs on grade may be designed using a coefficient of subgrade reaction of 210 pounds per cubic inch (pci) assuming the slab-on-grade base course is underlain by structural fill placed and compacted as outlined above. A 4- to 6-inch-thick capillary break layer should be placed over the prepared subgrade. This material should consist of pea gravel or 5/8 inch clean angular rock. A perimeter drainage system is recommended unless interior slab areas are elevated a minimum of 12 inches above adjacent exterior grades. If installed, a perimeter drainage system should consist of a 4-inch diameter perforated drain pipe surrounded by a minimum 6 inches of drain rock wrapped in a non-woven geosynthetic filter fabric to reduce migration of soil particles into the drainage system. The perimeter drainage system should discharge by gravity flow to a suitable stormwater system. Exterior grades surrounding buildings should be sloped at a minimum of one percent to facilitate surface water flow away from the building and preferably with a relatively impermeable surface cover immediately adjacent to the building. February 10, 2022 Page 8 of 10 Geotechnical Evaluation www.cobaltgeo.com (206) 331-1097 Erosion and Sediment Control Erosion and sediment control (ESC) is used to reduce the transportation of eroded sediment to wetlands, streams, lakes, drainage systems, and adjacent properties. Erosion and sediment control measures should be implemented, and these measures should be in general accordance with local regulations. At a minimum, the following basic recommendations should be incorporated into the design of the erosion and sediment control features for the site: Schedule the soil, foundation, utility, and other work requiring excavation or the disturbance of the site soils, to take place during the dry season (generally May through September). However, provided precautions are taken using Best Management Practices (BMP’s), grading activities can be completed during the wet season (generally October through April). All site work should be completed and stabilized as quickly as possible. Additional perimeter erosion and sediment control features may be required to reduce the possibility of sediment entering the surface water. This may include additional silt fences, silt fences with a higher Apparent Opening Size (AOS), construction of a berm, or other filtration systems. Any runoff generated by dewatering discharge should be treated through construction of a sediment trap if there is sufficient space. If space is limited other filtration methods will need to be incorporated. Utilities Utility trenches should be excavated according to accepted engineering practices following OSHA (Occupational Safety and Health Administration) standards, by a contractor experienced in such work. The contractor is responsible for the safety of open trenches. Traffic and vibration adjacent to trench walls should be reduced; cyclic wetting and drying of excavation side slopes should be avoided. Depending upon the location and depth of some utility trenches, groundwater flow into open excavations could be experienced, especially during or shortly following periods of precipitation. In general, silty and sandy soils were encountered at shallow depths in the explorations at this site. These soils have low cohesion and density and will have a tendency to cave or slough in excavations. Shoring or sloping back trench sidewalls is required within these soils in excavations greater than 4 feet deep. All utility trench backfill should consist of imported structural fill or suitable on site soils. Utility trench backfill placed in or adjacent to buildings and exterior slabs should be compacted to at least 95 percent of the maximum dry density based on ASTM Test Method D1557. The upper 5 feet of utility trench backfill placed in pavement areas should be compacted to at least 95 percent of the maximum dry density based on ASTM Test Method D1557. Below 5 feet, utility trench backfill in pavement areas should be compacted to at least 90 percent of the maximum dry density based on ASTM Test Method D1557. Pipe bedding should be in accordance with the pipe manufacturer's recommendations. The contractor is responsible for removing all water-sensitive soils from the trenches regardless of the backfill location and compaction requirements. Depending on the depth and location of the proposed utilities, we anticipate the need to re-compact existing fill soils below the utility structures and pipes. The contractor should use appropriate equipment and methods to avoid damage to the utilities and/or structures during fill placement and compaction procedures. February 10, 2022 Page 9 of 10 Geotechnical Evaluation www.cobaltgeo.com (206) 331-1097 CONSTRUCTION FIELD REVIEWS Cobalt Geosciences should be retained to provide part time field review during construction in order to verify that the soil conditions encountered are consistent with our design assumptions and that the intent of our recommendations is being met. This will require field and engineering review to: Monitor and test structural fill placement and soil compaction Observe bearing capacity at foundation locations Observe slab-on-grade preparation Verify soil conditions in infiltration system locations Monitor foundation drainage placement Observe excavation stability Geotechnical design services should also be anticipated during the subsequent final design phase to support the structural design and address specific issues arising during this phase. Field and engineering review services will also be required during the construction phase in order to provide a Final Letter for the project. CLOSURE This report was prepared for the exclusive use of Don Bora and his appointed consultants. Any use of this report or the material contained herein by third parties, or for other than the intended purpose, should first be approved in writing by Cobalt Geosciences, LLC. The recommendations contained in this report are based on assumed continuity of soils with those of our test holes and assumed structural loads. Cobalt Geosciences should be provided with final architectural and civil drawings when they become available in order that we may review our design recommendations and advise of any revisions, if necessary. Use of this report is subject to the Statement of General Conditions provided in Appendix A. It is the responsibility of Don Bora who is identified as “the Client” within the Statement of General Conditions, and its agents to review the conditions and to notify Cobalt Geosciences should any of these not be satisfied. Sincerely, Cobalt Geosciences, LLC 2/10/2022 Phil Haberman, PE, LG, LEG Principal February 10, 2022 Page 10 of 10 Geotechnical Evaluation www.cobaltgeo.com (206) 331-1097 Statement of General Conditions USE OF THIS REPORT: This report has been prepared for the sole benefit of the Client or its agent and may not be used by any third party without the express written consent of Cobalt Geosciences and the Client. Any use which a third party makes of this report is the responsibility of such third party. BASIS OF THE REPORT: The information, opinions, and/or recommendations made in this report are in accordance with Cobalt Geosciences present understanding of the site specific project as described by the Client. The applicability of these is restricted to the site conditions encountered at the time of the investigation or study. If the proposed site specific project differs or is modified from what is described in this report or if the site conditions are altered, this report is no longer valid unless Cobalt Geosciences is requested by the Client to review and revise the report to reflect the differing or modified project specifics and/or the altered site conditions. STANDARD OF CARE: Preparation of this report, and all associated work, was carried out in accordance with the normally accepted standard of care in the state of execution for the specific professional service provided to the Client. No other warranty is made. INTERPRETATION OF SITE CONDITIONS: Soil, rock, or other material descriptions, and statements regarding their condition, made in this report are based on site conditions encountered by Cobalt Geosciences at the time of the work and at the specific testing and/or sampling locations. Classifications and statements of condition have been made in accordance with normally accepted practices which are judgmental in nature; no specific description should be considered exact, but rather reflective of the anticipated material behavior. Extrapolation of in situ conditions can only be made to some limited extent beyond the sampling or test points. The extent depends on variability of the soil, rock and groundwater conditions as influenced by geological processes, construction activity, and site use. VARYING OR UNEXPECTED CONDITIONS: Should any site or subsurface conditions be encountered that are different from those described in this report or encountered at the test locations, Cobalt Geosciences must be notified immediately to assess if the varying or unexpected conditions are substantial and if reassessments of the report conclusions or recommendations are required. Cobalt Geosciences will not be responsible to any party for damages incurred as a result of failing to notify Cobalt Geosciences that differing site or sub-surface conditions are present upon becoming aware of such conditions. PLANNING, DESIGN, OR CONSTRUCTION: Development or design plans and specifications should be reviewed by Cobalt Geosciences, sufficiently ahead of initiating the next project stage (property acquisition, tender, construction, etc), to confirm that this report completely addresses the elaborated project specifics and that the contents of this report have been properly interpreted. Specialty quality assurance services (field observations and testing) during construction are a necessary part of the evaluation of sub-subsurface conditions and site preparation works. Site work relating to the recommendations included in this report should only be carried out in the presence of a qualified geotechnical engineer; Cobalt Geosciences cannot be responsible for site work carried out without being present. Cobalt Geosciences, LLCP.O. Box 82243 Kenmore, WA 98028 (206) 331-1097 www.cobaltgeo.com cobaltgeo@gmail.com SITE PLAN FIGURE 1 N Proposed Residence 29xx NE 5th Place Renton, Washington Subject Property TP-1 Attachment Cobalt Geosciences, LLCPO Box 1792North Bend, WA 98045 (206) 331-1097 www.cobaltgeo.com phil@cobaltgeo.com PT Well-graded gravels, gravels, gravel-sand mixtures, little or no fines Poorly graded gravels, gravel-sand mixtures, little or no fines Silty gravels, gravel-sand-silt mixtures Clayey gravels, gravel-sand-clay mixtures Well-graded sands, gravelly sands, little or no fines COARSE GRAINED SOILS (more than 50% retained on No. 200 sieve) Primarily organic matter, dark in color, and organic odor Peat, humus, swamp soils with high organic content (ASTM D4427)HIGHLY ORGANIC SOILS FINE GRAINED SOILS (50% or more passes the No. 200 sieve) MAJOR DIVISIONS SYMBOL TYPICAL DESCRIPTION Gravels (more than 50% of coarse fraction retained on No. 4 sieve) Sands (50% or more of coarse fraction passes the No. 4 sieve) Silts and Clays(liquid limit lessthan 50) Silts and Clays (liquid limit 50 or more) Organic Inorganic Organic Inorganic Sands with Fines(more than 12%fines) Clean Sands (less than 5%fines) Gravels with Fines (more than 12% fines) Clean Gravels (less than 5% fines) Unified Soil Classification System (USCS) Poorly graded sand, gravelly sands, little or no fines Silty sands, sand-silt mixtures Clayey sands, sand-clay mixtures Inorganic silts of low to medium plasticity, sandy silts, gravelly silts, or clayey silts with slight plasticity Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays, lean clays Organic silts and organic silty clays of low plasticity Inorganic silts, micaceous or diatomaceous fine sands or silty soils, elastic silt Inorganic clays of medium to high plasticity, sandy fat clay, or gravelly fat clay Organic clays of medium to high plasticity, organic silts Moisture Content Definitions Grain Size Definitions Dry Absence of moisture, dusty, dry to the touch Moist Damp but no visible water Wet Visible free water, from below water table Grain Size Definitions Description Sieve Number and/or Size Fines <#200 (0.08 mm) Sand -Fine -Medium -Coarse Gravel -Fine -Coarse Cobbles Boulders #200 to #40 (0.08 to 0.4 mm) #40 to #10 (0.4 to 2 mm) #10 to #4 (2 to 5 mm) #4 to 3/4 inch (5 to 19 mm) 3/4 to 3 inches (19 to 76 mm) 3 to 12 inches (75 to 305 mm) >12 inches (305 mm) Classification of Soil Constituents MAJOR constituents compose more than 50 percent, by weight, of the soil. Major constituents are capitalized (i.e., SAND). Minor constituents compose 12 to 50 percent of the soil and precede the major constituents (i.e., silty SAND). Minor constituents preceded by “slightly” compose 5 to 12 percent of the soil (i.e., slightly silty SAND). Trace constituents compose 0 to 5 percent of the soil(i.e., slightly silty SAND, trace gravel). Relative Density Consistency (Coarse Grained Soils) (Fine Grained Soils) N, SPT, Relative Blows/FT Density 0 - 4 Very loose 4 - 10 Loose 10 - 30 Medium dense 30 - 50 Dense Over 50 Very dense N, SPT, Relative Blows/FT Consistency Under 2 Very soft 2 - 4 Soft4 - 8 Medium stiff8 - 15 Stiff15 - 30 Very stiff Over 30 Hard Cobalt Geosciences, LLCP.O. Box 82243Kenmore, WA 98028(206) 331-1097 www.cobaltgeo.com cobaltgeo@gmail.com Soil Classification Chart Figure C1 Proposed Residence 29xx NE 5th Place Renton, Washington Test Pit Logs Cobalt Geosciences, LLCP.O. Box 82243 Kenmore, WA 98028 (206) 331-1097 www.cobaltgeo.com cobaltgeo@gmail.com Test Pit TP-1 Date: February 2022 Contractor: Jim Depth: 10’ Elevation: Logged By: PH Checked By: SC Groundwater: None Material Description Moisture Content (%)PlasticLimit Liquid Limit 10 20 30 400 50 1 2 3 4 5 6 DCP Equivalent N-Value 7 8 9 10 Loose to medium dense, silty-fine to medium grained sand with gravel, dark yellowish brown to grayish brown, moist. (Weathered Outwash?) SM/ SP End of Test Pit 10’ Topsoil/Vegetation SM/SP Medium dense, silty-fine to medium grained sand trace gravel grayish brown, moist. (Recessional Outwash) Some caving 6'&ÄÄ&10A$14#A5(4A4'5+&'0%'':+56+0)A%10&+6+105#0& 4Ä IN COMPLIANCE WITH CITY OF RENTON STANDARDS LEGEND SE 1/4, SW 1/4, SEC. 9, T. 23 N., R. 5 E., W.M. PROJECT INFORMATION 7227800631 2900 NE 5TH PL RENTON, WA 98056 R- 8 RENTON 6) $&5(6 AS SURVEYED LOT 2, CITY OF RENTON SHORT PLAT NO. LUA18-000445, RECORDING NO.20181113900001, RECORDS OF KING COUNTY, WASHINGTON LEGAL DESCRIPTION 5(4A4'5+&'0%'A&10$14#%A 1055 South Grady Way – 6th Floor | Renton, WA 98057 (425) 430-7200Date Prepared: Name:PE Registration No:Firm Name:Firm Address:Phone No.Email Address:Project Name: Project Owner:CED Plan # (LUA):Phone:CED Permit # (C):Address: Site Address:Street Intersection:Addt'l Project Owner:Parcel #(s):Phone:Address: Clearing and grading greater than or equal to 5,000 board feet of timber? Yes/No:NOWater Service Provided by:If Yes, Provide Forest Practice Permit #:Sewer Service Provided by: 10.1%Total Estimated Construction CostsEA + B + C + D39,392.46$ Estimated Civil Construction Permit - Construction Costs2Stormwater (Drainage)C18,395.51$ As outlined in City Ordinance No. 4345, 50% of the plan review and inspection fees are to be paid at Permit Submittal. The balance is due at Permit Issuance. Significant changes or additional review cycles (beyond 3 cycles) during the review process may result in adjustments to the final review fees.Roadway (Erosion Control + Transportation)D20,996.95$ WaterA-$ Wastewater (Sanitary Sewer)B-$ AddressAbbreviated Legal Description:RENTON HIGHLANDS #2 CORRECT PLAT LOT 2 RENTON BLA# LUA18-000445 REC# 20181113900001 SD BLALOC IN LOT 7 OF BLK 23 OF SD PLATCity, State, Zip2900 NE 5TH PL RENTON, WA 980562900 NE 5TH PL Additional Project OwnerNE 5TH PL and INDEX AVE NEC23000315##-######206-859-30947/30/2023Prepared by:FOR APPROVALProject Phase 1admin@effectiveengineeringpllc.com Benjamin P. Anstey, PE20614Effective Engineering PLLC8627 NE 180th Street, Bothell, WA206-303-76392 All prices include labor, equipment, materials, overhead, profit, and taxes. City of Renton Sales Tax is:SITE IMPROVEMENT BOND QUANTITY WORKSHEETPROJECT INFORMATIONCITY OF RENTONCITY OF RENTON1 Select 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 SubmittalPhoneEngineer Stamp Required (all cost estimates must have original wet stamp and signature)Clearing and GradingUtility ProvidersN/AProject Location and DescriptionProject Owner InformationSFRRENTON, WA 980567227800631Don BoraPage 1 of 1Ref 8-H Bond Quantity WorksheetSECTION I PROJECT INFORMATIONUnit Prices Updated: 01/07/2022Version: 01/07/2022Printed 7/29/202307/30/2023 CED Permit #:C23000315UnitReference #PriceUnitQuantity CostBackfill & compaction-embankmentESC-17.50$ CY Check dams, 4" minus rockESC-2SWDM 5.4.6.390.00$ Each Catch Basin ProtectionESC-3145.00$ Each3435.00Crushed surfacing 1 1/4" minusESC-4WSDOT 9-03.9(3)110.00$ CY DitchingESC-510.50$ CY Excavation-bulkESC-62.30$ CY270621.00Fence, siltESC-7SWDM 5.4.3.15.00$ LF4252,125.00Fence, Temporary (NGPE)ESC-81.75$ LF Geotextile FabricESC-93.00$ SY Hay Bale Silt TrapESC-100.60$ Each HydroseedingESC-11SWDM 5.4.2.40.90$ SY Interceptor Swale / DikeESC-121.15$ LF Jute MeshESC-13SWDM 5.4.2.24.00$ SY Level SpreaderESC-142.00$ LF Mulch, by hand, straw, 3" deepESC-15SWDM 5.4.2.12.90$ SY5001,450.00Mulch, by machine, straw, 2" deepESC-16SWDM 5.4.2.12.30$ SY Piping, temporary, CPP, 6"ESC-1713.75$ LF Piping, temporary, CPP, 8"ESC-1816.00$ LF Piping, temporary, CPP, 12"ESC-1920.50$ LF Plastic covering, 6mm thick, sandbaggedESC-20SWDM 5.4.2.34.60$ SY120552.00Rip Rap, machine placed; slopesESC-21WSDOT 9-13.1(2)51.00$ CY Rock Construction Entrance, 50'x15'x1'ESC-22SWDM 5.4.4.12,050.00$ Each12,050.00Rock Construction Entrance, 100'x15'x1'ESC-23SWDM 5.4.4.13,675.00$ Each Sediment pond riser assemblyESC-24SWDM 5.4.5.22,525.00$ Each Sediment trap, 5' high berm ESC-25SWDM 5.4.5.122.00$ LF Sed. trap, 5' high, riprapped spillway berm section ESC-26SWDM 5.4.5.180.00$ LF Seeding, by handESC-27SWDM 5.4.2.41.15$ SY Sodding, 1" deep, level groundESC-28SWDM 5.4.2.59.20$ SY Sodding, 1" deep, sloped groundESC-29SWDM 5.4.2.511.50$ SY TESC SupervisorESC-30125.00$ HR Water truck, dust controlESC-31SWDM 5.4.7160.00$ HR UnitReference #PriceUnitQuantity Cost EROSION/SEDIMENT SUBTOTAL:7,233.00SALES TAX @ 10.1%730.53EROSION/SEDIMENT TOTAL:7,963.53(A)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR EROSION & SEDIMENT CONTROLDescription No.(A)WRITE-IN-ITEMS Page 1 of 1Ref 8-H Bond Quantity WorksheetSECTION II.a EROSION_CONTROLUnit Prices Updated: 01/07/2022Version: 01/07/2022Printed 7/29/2023 CED Permit #:C23000315ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostGENERAL ITEMS Backfill & Compaction- embankmentGI-17.00$ CYBackfill & Compaction- trenchGI-210.25$ CYClear/Remove Brush, by hand (SY)GI-31.15$ SYBollards - fixedGI-4275.00$ EachBollards - removableGI-5520.00$ EachClearing/Grubbing/Tree RemovalGI-611,475.00$ AcreExcavation - bulkGI-72.30$ CYExcavation - TrenchGI-85.75$ CYFencing, cedar, 6' highGI-923.00$ LFFencing, chain link, 4'GI-1044.00$ LFFencing, chain link, vinyl coated, 6' highGI-1123.00$ LFFencing, chain link, gate, vinyl coated, 20' GI-121,600.00$ EachFill & compact - common barrowGI-1328.75$ CYFill & compact - gravel baseGI-1431.00$ CYFill & compact - screened topsoilGI-1544.75$ CYGabion, 12" deep, stone filled mesh GI-1674.50$ SYGabion, 18" deep, stone filled mesh GI-17103.25$ SYGabion, 36" deep, stone filled meshGI-18172.00$ SYGrading, fine, by handGI-192.90$ SY250725.00Grading, fine, with graderGI-202.30$ SYMonuments, 3' LongGI-211,025.00$ EachSensitive Areas SignGI-228.00$ EachSodding, 1" deep, sloped groundGI-239.25$ SYSurveying, line & gradeGI-24975.00$ DaySurveying, lot location/linesGI-252,050.00$ AcreTopsoil Type A (imported)GI-2632.75$ CYTraffic control crew ( 2 flaggers )GI-27137.75$ HRTrail, 4" chipped woodGI-289.15$ SYTrail, 4" crushed cinderGI-2910.25$ SYTrail, 4" top courseGI-3013.75$ SYConduit, 2"GI-315.75$ LFWall, retaining, concreteGI-3263.00$ SFWall, rockeryGI-3317.25$ SFSUBTOTAL THIS PAGE:725.00(B)(C)(D)(E)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B)(C)Page 1 of 3Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 01/07/2022Version: 01/07/2022Printed 7/29/2023 CED Permit #:C23000315ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B)(C)ROAD IMPROVEMENT/PAVEMENT/SURFACINGAC Grinding, 4' wide machine < 1000syRI-134.50$ SYAC Grinding, 4' wide machine 1000-2000syRI-218.25$ SYAC Grinding, 4' wide machine > 2000syRI-311.50$ SYAC Removal/DisposalRI-440.00$ SYBarricade, Type III ( Permanent )RI-564.25$ LFGuard RailRI-634.50$ LFCurb & Gutter, rolledRI-719.50$ LF26507.00Curb & Gutter, verticalRI-814.25$ LF1261,795.50Curb and Gutter, demolition and disposalRI-920.50$ LFCurb, extruded asphaltRI-106.25$ LFCurb, extruded concreteRI-118.00$ LFSawcut, asphalt, 3" depthRI-123.00$ LF154462.00Sawcut, concrete, per 1" depthRI-135.00$ LFSealant, asphaltRI-142.25$ LFShoulder, gravel, 4" thickRI-1517.25$ SYSidewalk, 4" thickRI-1643.50$ SY954,132.50Sidewalk, 4" thick, demolition and disposalRI-1737.00$ SYSidewalk, 5" thickRI-1847.00$ SYSidewalk, 5" thick, demolition and disposalRI-1946.00$ SYSign, Handicap RI-2097.00$ EachStriping, per stallRI-218.00$ EachStriping, thermoplastic, ( for crosswalk )RI-223.50$ SFStriping, 4" reflectorized lineRI-230.55$ LFAdditional 2.5" Crushed SurfacingRI-244.15$ SYHMA 1/2" Overlay 1.5" RI-2516.00$ SYHMA 1/2" Overlay 2"RI-2620.75$ SYHMA Road, 2", 4" rock, First 2500 SYRI-2732.25$ SYHMA Road, 2", 4" rock, Qty. over 2500SYRI-2824.00$ SYHMA Road, 4", 6" rock, First 2500 SYRI-2951.75$ SY402,070.00HMA Road, 4", 6" rock, Qty. over 2500 SYRI-3042.50$ SYHMA Road, 4", 4.5" ATBRI-3143.50$ SYGravel Road, 4" rock, First 2500 SYRI-3217.25$ SYGravel Road, 4" rock, Qty. over 2500 SYRI-3311.50$ SYThickened EdgeRI-3410.00$ LFSUBTOTAL THIS PAGE:8,967.00(B)(C)(D)(E)Page 2 of 3Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 01/07/2022Version: 01/07/2022Printed 7/29/2023 CED Permit #:C23000315ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostSITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR STREET AND SITE IMPROVEMENTSQuantity Remaining (Bond Reduction) (B)(C)PARKING LOT SURFACINGNo.2" AC, 2" top course rock & 4" borrowPL-124.00$ SY2" AC, 1.5" top course & 2.5" base coursePL-232.00$ SY4" select borrowPL-35.75$ SY1.5" top course rock & 2.5" base coursePL-416.00$ SYSUBTOTAL PARKING LOT SURFACING:(B)(C)(D)(E)LANDSCAPING & VEGETATIONNo.Street TreesLA-1380.00$ EACH31,140.00Median LandscapingLA-2-$ Right-of-Way LandscapingLA-31.07$ SF9401,005.80Wetland LandscapingLA-4-$ SUBTOTAL LANDSCAPING & VEGETATION:2,145.80(B)(C)(D)(E)TRAFFIC & LIGHTINGNo.SignsTR-1Street Light System ( # of Poles)TR-2Traffic SignalTR-3Traffic Signal ModificationTR-4SUBTOTAL TRAFFIC & LIGHTING:(B)(C)(D)(E)WRITE-IN-ITEMSSUBTOTAL WRITE-IN ITEMS:STREET AND SITE IMPROVEMENTS SUBTOTAL:11,837.80SALES TAX @ 10.1%1,195.62STREET AND SITE IMPROVEMENTS TOTAL:13,033.42(B)(C)(D)(E)Page 3 of 3Ref 8-H Bond Quantity WorksheetSECTION II.b TRANSPORTATIONUnit Prices Updated: 01/07/2022Version: 01/07/2022Printed 7/29/2023 CED Permit #:C23000315ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostDRAINAGE (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/DD-130.00$ SY* (CBs include frame and lid)BeehiveD-2103.00$ EachThrough-curb Inlet FrameworkD-3460.00$ EachCB Type ID-41,725.00$ Each58,625.00CB Type ILD-52,000.00$ EachCB Type II, 48" diameterD-63,500.00$ Each for additional depth over 4' D-7550.00$ FTCB Type II, 54" diameterD-84,075.00$ Each for additional depth over 4'D-9570.00$ FTCB Type II, 60" diameterD-104,225.00$ Each for additional depth over 4'D-11690.00$ FTCB Type II, 72" diameterD-126,900.00$ Each for additional depth over 4'D-13975.00$ FTCB Type II, 96" diameterD-1416,000.00$ Each for additional depth over 4'D-151,050.00$ FTTrash Rack, 12"D-16400.00$ EachTrash Rack, 15"D-17470.00$ EachTrash Rack, 18"D-18550.00$ EachTrash Rack, 21"D-19630.00$ EachCleanout, PVC, 4"D-20170.00$ Each1170.00Cleanout, PVC, 6"D-21195.00$ Each3585.00Cleanout, PVC, 8"D-22230.00$ EachCulvert, PVC, 4" D-2311.50$ LF57655.50Culvert, PVC, 6" D-2415.00$ LF1301,950.00Culvert, PVC, 8" D-2517.00$ LFCulvert, PVC, 12" D-2626.00$ LFCulvert, PVC, 15" D-2740.00$ LFCulvert, PVC, 18" D-2847.00$ LFCulvert, PVC, 24"D-2965.00$ LFCulvert, PVC, 30" D-3090.00$ LFCulvert, PVC, 36" D-31150.00$ LFCulvert, CMP, 8"D-3222.00$ LFCulvert, CMP, 12"D-3333.00$ LFSUBTOTAL THIS PAGE:11,985.50(B)(C)(D)(E)Quantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESRef 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 01/07/2022Version: 01/07/2022Printed 7/29/2023 CED Permit #:C23000315ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostQuantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESDRAINAGE (Continued)Culvert, CMP, 15"D-3440.00$ LFCulvert, CMP, 18"D-3547.00$ LFCulvert, CMP, 24"D-3664.00$ LFCulvert, CMP, 30"D-3790.00$ LFCulvert, CMP, 36"D-38150.00$ LFCulvert, CMP, 48"D-39218.00$ LFCulvert, CMP, 60"D-40310.00$ LFCulvert, CMP, 72"D-41400.00$ LFCulvert, Concrete, 8"D-4248.00$ LFCulvert, Concrete, 12"D-4355.00$ LFCulvert, Concrete, 15"D-4489.00$ LFCulvert, Concrete, 18"D-45100.00$ LFCulvert, Concrete, 24"D-46120.00$ LFCulvert, Concrete, 30"D-47145.00$ LFCulvert, Concrete, 36"D-48175.00$ LFCulvert, Concrete, 42"D-49200.00$ LFCulvert, Concrete, 48"D-50235.00$ LFCulvert, CPE Triple Wall, 6" D-5116.00$ LFCulvert, CPE Triple Wall, 8" D-5218.00$ LFCulvert, CPE Triple Wall, 12" D-5327.00$ LFCulvert, CPE Triple Wall, 15" D-5440.00$ LFCulvert, CPE Triple Wall, 18" D-5547.00$ LFCulvert, CPE Triple Wall, 24" D-5664.00$ LFCulvert, CPE Triple Wall, 30" D-5790.00$ LFCulvert, CPE Triple Wall, 36" D-58149.00$ LFCulvert, LCPE, 6"D-5969.00$ LFCulvert, LCPE, 8"D-6083.00$ LFCulvert, LCPE, 12"D-6196.00$ LFCulvert, LCPE, 15"D-62110.00$ LFCulvert, LCPE, 18"D-63124.00$ LFCulvert, LCPE, 24"D-64138.00$ LFCulvert, LCPE, 30"D-65151.00$ LFCulvert, LCPE, 36"D-66165.00$ LFCulvert, LCPE, 48"D-67179.00$ LFCulvert, LCPE, 54"D-68193.00$ LFSUBTOTAL THIS PAGE:(B)(C)(D)(E)Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 01/07/2022Version: 01/07/2022Printed 7/29/2023 CED Permit #:C23000315ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostQuantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESDRAINAGE (Continued)Culvert, LCPE, 60"D-69206.00$ LFCulvert, LCPE, 72"D-70220.00$ LFCulvert, HDPE, 6"D-7148.00$ LFCulvert, HDPE, 8"D-7260.00$ LFCulvert, HDPE, 12"D-7385.00$ LFCulvert, HDPE, 15"D-74122.00$ LFCulvert, HDPE, 18"D-75158.00$ LFCulvert, HDPE, 24"D-76254.00$ LFCulvert, HDPE, 30"D-77317.00$ LFCulvert, HDPE, 36"D-78380.00$ LFCulvert, HDPE, 48"D-79443.00$ LFCulvert, HDPE, 54"D-80506.00$ LFCulvert, HDPE, 60"D-81570.00$ LFCulvert, HDPE, 72"D-82632.00$ LFPipe, Polypropylene, 6"D-8396.00$ LFPipe, Polypropylene, 8"D-84100.00$ LFPipe, Polypropylene, 12"D-85100.00$ LFPipe, Polypropylene, 15"D-86103.00$ LFPipe, Polypropylene, 18"D-87106.00$ LFPipe, Polypropylene, 24"D-88119.00$ LFPipe, Polypropylene, 30"D-89136.00$ LFPipe, Polypropylene, 36"D-90185.00$ LFPipe, Polypropylene, 48"D-91260.00$ LFPipe, Polypropylene, 54"D-92381.00$ LFPipe, Polypropylene, 60"D-93504.00$ LFPipe, Polypropylene, 72"D-94625.00$ LFCulvert, DI, 6"D-9570.00$ LFCulvert, DI, 8"D-96101.00$ LFCulvert, DI, 12"D-97121.00$ LF22.52,722.50Culvert, DI, 15"D-98148.00$ LFCulvert, DI, 18"D-99175.00$ LFCulvert, DI, 24"D-100200.00$ LFCulvert, DI, 30"D-101227.00$ LFCulvert, DI, 36"D-102252.00$ LFCulvert, DI, 48"D-103279.00$ LFCulvert, DI, 54"D-104305.00$ LFCulvert, DI, 60"D-105331.00$ LFRef 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 01/07/2022Version: 01/07/2022Printed 7/29/2023 CED Permit #:C23000315ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostQuantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESCulvert, DI, 72"D-106357.00$ LFSUBTOTAL THIS PAGE:2,722.50(B)(C)(D)(E)Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 01/07/2022Version: 01/07/2022Printed 7/29/2023 CED Permit #:C23000315ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostQuantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESSpecialty Drainage ItemsDitching SD-110.90$ CYFlow Dispersal Trench (1,436 base+)SD-332.00$ LF French Drain (3' depth)SD-430.00$ LFGeotextile, laid in trench, polypropyleneSD-53.40$ SYMid-tank Access Riser, 48" dia, 6' deepSD-62,300.00$ EachPond Overflow SpillwaySD-718.25$ SYRestrictor/Oil Separator, 12"SD-81,320.00$ EachRestrictor/Oil Separator, 15"SD-91,550.00$ EachRestrictor/Oil Separator, 18"SD-101,950.00$ EachRiprap, placedSD-1148.20$ CYTank End Reducer (36" diameter)SD-121,375.00$ EachInfiltration pond testingSD-13143.00$ HRPermeable PavementSD-14Permeable Concrete SidewalkSD-15Culvert, Box __ ft x __ ftSD-16SUBTOTAL SPECIALTY DRAINAGE ITEMS:(B)(C)(D)(E)STORMWATER FACILITIES (Include Flow Control and Water Quality Facility Summary Sheet and Sketch)Detention PondSF-1Each Detention TankSF-2Each Detention VaultSF-3Each Infiltration PondSF-4Each Infiltration TankSF-5Each Infiltration VaultSF-6Each Infiltration TrenchesSF-7Each Basic Biofiltration SwaleSF-8Each Wet Biofiltration SwaleSF-9Each WetpondSF-10Each WetvaultSF-11Each Sand FilterSF-12Each Sand Filter VaultSF-13Each Linear Sand FilterSF-14Each Proprietary FacilitySF-15Each Bioretention FacilitySF-16Each SUBTOTAL STORMWATER FACILITIES:(B)(C)(D)(E)Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 01/07/2022Version: 01/07/2022Printed 7/29/2023 CED Permit #:C23000315ExistingFuture PublicPrivateRight-of-WayImprovementsImprovements(D) (E)DescriptionNo. Unit PriceUnitQuant.CostQuant.CostQuant.CostQuant.CostQuantity Remaining (Bond Reduction) (B)(C)SITE IMPROVEMENT BOND QUANTITY WORKSHEETFOR DRAINAGE AND STORMWATER FACILITIESWRITE-IN-ITEMS (INCLUDE ON-SITE BMPs)Perforated Stub-OutWI-11,000.00$ Each11,000.00Connection to existing SD MHWI-21,000.00$ Each11,000.00WI-3WI-4WI-5WI-6WI-7WI-8WI-9WI-10WI-11WI-12WI-13WI-14WI-15SUBTOTAL WRITE-IN ITEMS:1,000.001,000.00DRAINAGE AND STORMWATER FACILITIES SUBTOTAL:3,722.5012,985.50SALES TAX @ 10.1%375.971,311.54DRAINAGE AND STORMWATER FACILITIES TOTAL:4,098.4714,297.04(B) (C) (D) (E)Ref 8-H Bond Quantity WorksheetSECTION II.c DRAINAGEUnit Prices Updated: 01/07/2022Version: 01/07/2022Printed 7/29/2023 1055 South Grady Way – 6th Floor | Renton, WA 98057 (425) 430-7200Date:Name:Project Name: PE Registration No:CED Plan # (LUA):Firm Name:CED Permit # (C):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)13,033.42$ Future Public Improvements Subtotal(c)-$ Stormwater & Drainage Facilities (Public & Private) Subtotal(d)(d)18,395.51$ (e)(f)Site RestorationExisting Right-of-Way and Storm Drainage ImprovementsMaintenance Bond6,285.79$ Bond Reduction2Construction Permit Bond Amount 3Minimum Bond Amount is $10,000.001 Estimate Only - May involve multiple and variable components, which will be established on an individual basis by Development Engineering.2 The City of Renton allows one request only for bond reduction prior to the maintenance period. Reduction of not more than 70% of the original bond amount, provided that the remaining 30% willcover all remaining items to be constructed. 3 Required Bond Amounts are subject to review and modification by Development Engineering.* Note: The word BOND as used in this document means any financial guarantee acceptable to the City of Renton.** Note: All prices include labor, equipment, materials, overhead, profit, and taxes. EST1((b) + (c) + (d)) x 20%-$ MAINTENANCE BOND */**(after final acceptance of construction)7,963.53$ 13,033.42$ 37,945.63$ 7,963.53$ -$ 18,395.51$ -$ 45,909.17$ P (a) x 100%SITE IMPROVEMENT BOND QUANTITY WORKSHEET BOND CALCULATIONS10/30/2022 Benjamin P. Anstey, PE20614Effective Engineering PLLCR((b x 150%) + (d x 100%))S(e) x 150% + (f) x 100%Bond Reduction: Existing Right-of-Way Improvements (Quantity Remaining)2Bond Reduction: Stormwater & Drainage Facilities (Quantity Remaining)2T(P +R - S)Prepared by:Project InformationCONSTRUCTION BOND AMOUNT */**(prior to permit issuance)206-303-7639admin@effectiveengineeringpllc.comSFR##-######2900 NE 5TH PL RENTON, WA 980567227800631FOR APPROVALC230003158627 NE 180th Street, Bothell, WAPage 1 of 1Ref 8-H Bond Quantity WorksheetSECTION III. BOND WORKSHEETUnit Prices Updated: 01/07/2022Version: 01/07/2022Printed 7/29/2023