Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
RS_DRAINAGE_TIR_171218_V1
Western Washington Division Eastern Washington Division 165 NE Juniper St., Ste 201, Issaquah, WA 98027 108 East 2 nd Street, Cle Elum, WA 98922 Phone: (425) 392-0250 Fax: (425) 391-3055 Phone: (509) 674-7433 Fax: (509) 674-7419 www.EncompassES.net PRELIMINARY TECHNICAL INFORMATION REPORT For Huynh Short Plat 2007 Union Ave NE Renton, WA 98059 December 12th 2017 Prepared by: Samuel Salo Encompass Engineering Job No. 17597 Prepared For: Kathy Huynh 2806 NE Sunset Blvd. Suite F Renton, WA 98056 RECEIVED 12/27/2017 amorganroth PLANNING DIVISION Huynh Short Plat Technical Information Report 12/12/2017 Page i Table of Contents I. PROJECT OVERVIEW ................................................................................................................ 1 II. CONDITIONS AND REQUIREMENTS SUMMARY ...................................................................... 2 III. OFF-SITE ANALYSIS .................................................................................................................. 4 IV. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN ............................. 8 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN ..................................................................... 11 VI. SPECIAL REPORTS AND STUDIES ............................................................................................ 11 VII. OTHER PERMITS ..................................................................................................................... 11 VIII. CSWPPP ANALYSIS AND DESIGN............................................................................................ 11 IX. BOND QUANTITIES and DECLARATION of COVENANT .......................................................... 11 X. OPERATION AND MAINTENANCE MANUAL .......................................................................... 11 Appendix Geotechnical Engineering Report by Migizi Group Revised 09/28/2017. WWHM Output Huynh Short Plat Technical Information Report 12/12/2017 Page 1 I. PROJECT OVERVIEW Site Address: 2007 Union Ave NE, Renton, WA 98059 (See Vicinity Map) King County Tax Parcel: 042305-9076 Vicinity Map The site is developed with an existing single-family residence, detached garage and gravel driveway. The site is comprised of grasses with trees and shrubs around the boundaries of the property. There are a few scattered small gardens on the eastern half of the property. The eastern portion of the site slopes to the southeast at 5-8%. The western portion of the site slopes to the northwest at 8-15%. The USDA Web Soil Survey maps the soil on the site as Alderwood gravelly sandy loam at 8-15% slopes (See Soils Map on Following Page). A geotechnical engineering report is included in the Appendix. Huynh Short Plat Technical Information Report 12/12/2017 Page 2 Soils Map II. CONDITIONS AND REQUIREMENTS SUMMARY The 2017 City of Renton Surface Water Design Manual along with the 2016 King County Surface Water Design Manual was utilized for this report per the City of Renton requirements. Core Requirements Core Requirement #1: Discharge at the Natural Location The proposed development runoff will follow existing drainage patterns and will be routed to same discharge points as existing condition. Refer to the Downstream Analysis in Section III for a complete description of the existing drainage path. Core Requirement #2: Offsite Analysis A Level 1 Downstream analysis has been prepared and is included in Section III of this TIR. Core Requirement #3: Flow Control Facilities Stormwater flow in the form of rooftop runoff will be controlled using downspouts conveyed to gravel bed infiltration systems. Driveway runoff will be controlled using permeable pavement. After applying the BMP credits for the permeable pavement and modeling the gravel bed infiltration systems the WWHM output displayed an increase in runoff of less than 0.15 CFS using 15-minute timesteps, therefore the project meets the Huynh Short Plat Technical Information Report 12/12/2017 Page 3 exemption for flow control duration standard areas on page 1-41 of the City of Renton Surface Water Design Manual and no further flow control facilities are required. See Section IV of this TIR for a detailed breakdown of areas used for modeling. Core Requirement #4: Conveyance System Design and analysis of on and off-site conveyance systems will be submitted with final engineering. Core Requirement #5: Erosion and Sediment Control A temporary erosion and sediment control (TESC) plan provides BMPs to be implemented during construction. This plan and included BMPs will be provided during final engineering. Core Requirement #6: Maintenance and Operations See Section X – Operation and Maintenance Manual Core Requirement #7: Financial Guarantees and Liability The owner will arrange for any financial guarantees and liabilities required by the permit. Core Requirement #8: Water Quality Facilities The assumption has been made that the permeable pavement will be sufficient for water quality. Tests will be conducted during final engineering to verify this per City of Renton Surface Water Design Manual Section C.2.7 Core Requirement #9: Flow Control BMPs Rooftop Runoff will be infiltrated using gravel bed infiltration systems. Driveway runoff will be infiltrated via permeable pavement. Special Requirements Special Requirement #1: Other Adopted Area-Specific Requirements Critical Drainage Area – N/A Master Drainage Plan – N/A Basin Plan – May Creek & Lower Cedar River Drainage Basin Lake management Plan – N/A Shared Facility Drainage Plan – N/A Special Requirement #2: Flood Hazard Area Delineation The limits of this project do not lie in a 100-year floodplain Special Requirement #3: Flood Protection Facilities This special requirement is for Class 1 or 2 streams with an existing flood protection facility. The site does not contain any streams and is therefore not applicable. Special Requirement #4: Source controls This project is a single-family residential project, therefore this requirement is not applicable. Special Requirement #5: Oil Control This project is not considered high-use in need of oil control. Huynh Short Plat Technical Information Report 12/12/2017 Page 4 III. OFF-SITE ANALYSIS A Level 1 Downstream Drainage Analysis was performed July 13, 2017 at around 8:00 AM. The weather was cloudy and roughly 63°. The site is developed with an existing single-family residence, detached garage and gravel driveway. The site is comprised of grasses, trees and shrubs around the boundaries of the property. There are a few scattered small gardens on the northern side of the property. The eastern portion of the site slopes to the southeast at 5-8%. The western portion of the site slopes to the northwest at 8-15%. Runoff from the eastern portion of the site sheet flows across the property and down the gravel driveway to the east and southeast towards Union Ave NE. It is then collected by a CB off the southeast corner of the property. The runoff then flows south along Union Ave NE before draining into Honey Creek. This is creek runs more than ¼ mile downstream where the level one analysis was completed. Runoff from the western portion of the lot. Sheet flows to the western and northwestern edges of the lot. It then flows onto the adjacent church parking lot, then into the detention pond on the northeastern side of the parking lot. This ponds overflow drains into a CB and flows west along NE 21st St then south along Redmond Ave NE. This is where the level one analysis was completed. Using the City of Renton CORMaps it was found that the runoff then crosses NE 19 th St and drains into detention vault. Based on this analysis, there are no potential problems downstream of the project site. Downstream photos are included on the following pages. Huynh Short Plat Technical Information Report 12/12/2017 Page 5 Photo 1: Site Frontage Photo 2: CB on Southeast Corner of Property Huynh Short Plat Technical Information Report 12/12/2017 Page 6 Photo 3: Taken Facing South on Union Avenue Photo 4: Detention Pond on Huynh Short Plat Technical Information Report 12/12/2017 Page 7 Photo 5: Taken Facing the West on NE 21st St Huynh Short Plat Technical Information Report 12/12/2017 Page 8 IV. FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN Area Breakdown for Eastern Drainage Basin Total Predeveloped Area 0.35 Acres Total Mitigated Area 0.27 Acres Driveway Area 0.02 Acres (Modeled as 50% due to permeable pavement) Rooftop Area 0.04 Acres Roadway Area .06 Acres (Modeled as 50% due to permeable pavement) Pervious Total 0.15 Acres (Not including BMP credits) Difference in 100- year flow event. 0.134244-0.054456=0.08< 0.15 Area Breakdown for Western Drainage Basin Total Predeveloped Area 0.35 Acres Total Mitigated Area 0.48 Acres Driveway Area 0.02 Acres (Modeled as 50% due to permeable pavement) Rooftop Area 0.1 Acres Roadway Area 0.08 Acres (Modeled as 50% due to permeable pavement) Pervious Total 0.28 Acres (Not including BMP credits) Difference in 100-year flow event 0.089877-0.03859=0.051< 0.15 Basin maps are included on the following pages. Full WWHM output is included in the Appendix of this TIR Huynh Short Plat Technical Information Report 12/12/2017 Page 11 V. CONVEYANCE SYSTEM ANALYSIS AND DESIGN Conveyance system analysis and design will be provided with final engineering. VI. SPECIAL REPORTS AND STUDIES Geotechnical Engineering Report Dated 7/14/17 Revised 9/28/17. VII. OTHER PERMITS Building Permits will be required. VIII. CSWPPP ANALYSIS AND DESIGN CSWPPP Analysis and Design will be provided with final engineering. IX. BOND QUANTITIES and DECLARATION of COVENANT Bond Quantities and Declaration of Covenant will be provided with final engineering X. OPERATION AND MAINTENANCE MANUAL An Operation and Maintenance Manual will be provided with final engineering. Huynh Short Plat Technical Information Report 12/12/2017 Page 12 Appendix Geotechnical Report and WWHM Output ` Geotechnical Engineering Report Proposed Huynh 3 Lot Short Plat 2007 Union Ave NE Renton, Washington 98059 P/N 0423059076 July 14, 2017 Revised September 28, 2017 prepared for: Monsef Donogh Design Group Attention: Paul Monsef 2806 NE Sunset Blvd, Suite F Renton, Washington 98056 prepared by: Migizi Group, Inc. PO Box 44840 Tacoma, Washington 98448 (253) 537-9400 MGI Project P1003-T17 i TABLE OF CONTENTS Page No. 1.0 SITE AND PROJECT DESCRIPTION............................................................................................... 1 2.0 EXPLORATORY METHODS ............................................................................................................. 2 2.1 Test Pit Procedures ................................................................................................................ 2 2.2 Infiltration Test Procedures .................................................................................................. 3 3.0 SITE CONDITIONS ............................................................................................................................ 3 3.1 Surface Conditions ................................................................................................................. 3 3.2 Soil Conditions ....................................................................................................................... 3 3.3 Groundwater Conditions ...................................................................................................... 4 3.4 Infiltration Conditions ........................................................................................................... 4 3.5 Seismic Conditions ................................................................................................................. 5 3.6 Liquefaction Potential ............................................................................................................ 6 4.0 CONCLUSIONS AND RECOMMENDATIONS ............................................................................ 6 4.1 Site Preparation ...................................................................................................................... 7 4.2 Spread Footings ...................................................................................................................... 9 4.3 Slab-On-Grade-Floors .......................................................................................................... 10 4.4 Asphalt Pavement ................................................................................................................ 11 4.5 Structural Fill ........................................................................................................................ 12 5.0 RECOMMENDED ADDITIONAL SERVICES .............................................................................. 13 6.0 CLOSURE ........................................................................................................................................... 14 List of Tables Table 1. Approximate Locations and Depths of Explorations ............................................................................. 2 Table 2. Falling Head Period Test Results .............................................................................................................. 5 List of Figures Figure 1. Topographic and Location Map Figure 2. Site and Exploration Plan APPENDIX A Soil Classification Chart and Key to Test Data .................................................................................................. A-1 Log of Test Pits TP-1 through TP-4 ........................................................................................................... A-2…A-5 Page 1 of 14 MIGIZI GROUP, INC. PO Box 44840 PHONE (253) 537-9400 Tacoma, Washington 98448 FAX (253) 537-9401 July 14, 2017 Revised September 28, 2017 Monsef Donogh Design Group 2806 NE Sunset Blvd, Suite F Renton, WA 98056 Attention: Paul Monsef Subject: Geotechnical Engineering Report Kathy Huynh 3-Lot SP 2007 Union Ave NE Renton, WA 98059 P/N 0423059076 MGI Project P1003-T17 Dear Mr. Monsef: Migizi Group, Inc. (MGI) is pleased to submit this report describing the results of our geotechnical engineering evaluation of the proposed residential development in Renton, Washington. This report has been prepared for the exclusive use of Monsef Donogh Design Group, and their consultants, for specific application to this project, in accordance with generally accepted geotechnical engineering practice. 1.0 SITE AND PROJECT DESCRIPTION The project site consists of a rectangular-shaped, 0.74-acre residential parcel in Renton, Washington, as shown on the enclosed Topographic and Location Map (Figure 1). The subject property is situated along the west side of Union Ave NE, approximately 450 feet north of its intersection with NE 19th St. The project area is elongated from east to west, spanning approximately 400 feet along this orientation; extending upwards of 82 feet from north to south. The subject parcel has previously been developed, with an existing single-family residence and detached garage originally constructed in 1978 occupying the central portion of the site. Regions east and west of these structures are occupied by yard space, with the driveway entering the site from the northeast. Improvement plans involve the demolition of existing site features, and the eventual short-plat of the subject property; resulting in three residential lots. Preliminary plans have each lot being developed, and sharing a communal driveway which travels along the northern margin of the site. Resulting lots will range from 9,676 to 12,300 sf, and will increase numerically from east to west. Monsef Donogh Design Group –2007 Union Ave NE, Renton, WA July 14, 2017 / Revised September 28, 2017 Geotechnical Engineering Report P1003-T17 Migizi Group, Inc. Page 2 of 14 2.0 EXPLORATORY METHODS We explored surface and subsurface conditions at the project site on June 27, 2017 and September 26, 2017. Our exploration and evaluation program comprised the following elements: • Surface reconnaissance of the site; • Four test pit explorations (designated TP-1 through TP-4), advanced on June 27, 2017 and September 26, 2017; • One Small-Scale Pilot Infiltration Test (PIT), performed on September 26, 2017; and • A review of published geologic and seismologic maps and literature. Table 1 summarizes the approximate functional locations and termination depths of our subsurface explorations, and Figure 2 depicts their approximate relative locations. The following sections describe the procedures used for excavation of the test pits. TABLE 1 APPROXIMATE LOCATIONS AND DEPTHS OF EXPLORATIONS Exploration Functional Location Termination Depth (feet) TP-1 TP-2 TP-3 TP-4 Southwest corner of the project area Centrally, north side of project area Southeast corner of the project area Centrally, western half of the project area 10 8 5 6½ The specific number and locations of our explorations were selected in relation to the existing site features, under the constraints of surface access, underground utility conflicts, and budget considerations. It should be realized that the explorations performed and utilized for this evaluation reveal subsurface conditions only at discrete locations across the project site and that actual conditions in other areas could vary. Furthermore, the nature and extent of any such variations would not become evident until additional explorations are performed or until construction activities have begun. If significant variations are observed at that time, we may need to modify our conclusions and recommendations contained in this report to reflect the actual site conditions. 2.1 Test Pit Procedures Our exploratory test pits were excavated with a rubber-tracked mini-excavator operated by an excavation contractor under subcontract to MGI. An engineering geologist from our firm observed the test pit excavations, collected soil samples, and logged the subsurface conditions. The enclosed test pit logs indicate the vertical sequence of soils and materials encountered in our test pits, based on our field classifications. Where a soil contact was observed to be gradational or undulating, our logs indicate the average contact depth. We estimated the relative density and consistency of the in-situ soils by means of the excavation characteristics and the stability of the test Monsef Donogh Design Group –2007 Union Ave NE, Renton, WA July 14, 2017 / Revised September 28, 2017 Geotechnical Engineering Report P1003-T17 Migizi Group, Inc. Page 3 of 14 pit sidewalls. Our logs also indicate the approximate depths of any sidewall caving or groundwater seepage observed in the test pits. The soils were classified visually in general accordance with the system described in Figure A-1, which includes a key to the exploration log. Summary logs of our explorations are included as Figures A-2 through A-5. 2.2 Infiltration Test Procedures In-situ field infiltration testing was performed for determination of a Design Infiltration Rate in general accordance with the Small-Scale Pilot Infiltration Test (PIT) procedure, as described in Ref 6-A-2 of the 2017 City of Renton Surface Water Design Manual. The first step of this test procedure was to identify a suitable soil stratum for stormwater retention, and once completed, perform an excavation within this soil group with a minimum surface area of 12 square feet (sf). Once the excavation was completed, a vertical measuring rod marked in half-inch increments was installed towards the center of the test area. Water was then introduced into the test area, being conveyed through a 4-inch corrugated pipe to a splash block at the bottom of the excavation. Once 12 inches of water was developed at the bottom of the excavation, the test surface was saturated prior to testing. After the saturation period was completed, a steady state flow rate was developed in order to maintain 12 inches of head at the bottom of the test surface. This steady state rate was maintained for one hour. After completion of the steady state period, water was no longer introduced into the excavation, and infiltration of the existing water was allowed. We recorded the falling head rate for one hour, for comparison with the steady state rate. 3.0 SITE CONDITIONS The following sections present our observations, measurements, findings, and interpretations regarding, surface, soil, groundwater, and infiltration conditions. 3.1 Surface Conditions As previously indicated, the project site consists of a rectangular-shaped, 0.74-acre residential parcel in Renton, Washington. The subject property has previously been developed, with a single-family residence and detached garage originally constructed in 1978 occupying the central portions of the site. Regions east and west of these structures are occupied by yard space. A small garden area is located within the north side of the back-yard area. Vegetation on site is limited to two larger fir trees towards the western margin of the site, lawn grass, and scattered, ornamental trees/shrubs. The project area is relatively level, with minimal grade change observed over its extent. The subject property is situated within a densely populated residential area towards the northeast corner of the city limits of Renton. 3.2 Soil Conditions Our test pit explorations revealed relatively consistent subgrade conditions across the project area, generally consisting of a surface mantle of sod/topsoil, underlain by native glacial till soils. Renton, and the larger Puget Sound area in general, has been glaciated a number of times over the last 2.4 million years. The most recent of these glacial events, the Vashon Stade of the Fraser Glaciation, receded from this region approximately 13,500 years ago. The majority of near surface soils encountered within the Renton area are either directly associated with, or have been physically Monsef Donogh Design Group –2007 Union Ave NE, Renton, WA July 14, 2017 / Revised September 28, 2017 Geotechnical Engineering Report P1003-T17 Migizi Group, Inc. Page 4 of 14 altered by the Vashon glacial event. Glacial till is typically described as being a compact, coherent mixture of gravel, silt, clay and sand-sized clasts deposited along the base of glacial ice during a period of localized advancement. This material is generally encountered in a compact relative consistency given the fact that it was overridden by the ice mass shortly after deposition, and is commonly underlain by advance outwash soils. Underlying a surface mantle of sod and topsoil, we encountered native glacial till soils. The upper ± 3 feet of this soil group was highly weathered and encountered in a loose in situ condition. Unweathered glacial till was comprised of dense, gravelly, silty sand and was continuous through the termination depth of each of our subsurface explorations; a maximum depth of 10 feet below grade. A slight variation to the above described soil sequence was observed in test pit exploration TP-1, which was performed towards the west end of the project area. At this location, upwards of 3 feet of poorly to densely consolidated fill soils were encountered above native deposits. The import of fill soils at this location was evidently required for the development of a level lot. Fill soils were limited to the western margin of the project area, and will likely only be encountered in a small portion of project excavations. In the Geologic Map of the Renton Quadrangle, King County, Washington, as prepared by the Department of the Interior United States Geological Survey (USGS) (1965), the project site is mapped as containing Qvt, or Vashon-aged glacial till. The National Cooperative Soil Survey (NCSS) for King County, classifies soils onsite as AgC – Alderwood gravelly sandy loam, 8 to 15 percent slopes. This soil series is comprised primarily of gravelly sandy loam, and reportedly formed from glacial till deposits. Our subsurface explorations generally correspond with the mappings of the site performed by the USGS and NCSS. The enclosed exploration logs (Appendix A) provide a detailed description of the soil strata encountered in our subsurface explorations. 3.3 Groundwater Conditions We encountered slow seepage at a depth of approximately 9½ feet in the vicinity of test pit exploration TP-1. This is likely indicative of seasonally high groundwater, given the fact that our explorations were performed just outside of what is generally considered the rainy season, after what has been one the wettest winters/springs recorded in Western Washington. Seasonally perched groundwater, will also likely be encountered at shallow depths during extended periods of wet weather due to the poor permeability of site soils. 3.4 Infiltration Conditions As indicated in the Soil Conditions section of this report, the site is generally underlain by weathered glacial till soils at shallow elevations, transitioning to densely consolidated, unweathered glacial till soils with depth. This upper, weathered soil group can be utilized for stormwater retention, but native, unweathered glacial till soils should be considered an impermeable surface for design purposes. To account for fluctuations across the subgrade, a depth of 3 feet should be assumed for the contact with unweathered glacial till soils. Given the fact that an impermeable surface is present at relatively shallow depths across the project area, we anticipate that full infiltration is not feasible Monsef Donogh Design Group –2007 Union Ave NE, Renton, WA July 14, 2017 / Revised September 28, 2017 Geotechnical Engineering Report P1003-T17 Migizi Group, Inc. Page 5 of 14 for this project. However, limited infiltration, utilizing a system of rain gardens, permeable pavement materials, and/or shallow trenches, likely can be implemented. A minimum separation of 12 inches should be maintained between the invert elevations of these retention facilities and impermeable surfaces encountered on site for individual lot infiltration. On September 26, 2017, an engineering geologist from MGI performed field infiltration testing utilizing the procedures at the onset of this report. The field test (INF-1) was performed towards the center of the western area of subject property, in the vicinity of test pit exploration TP-4, as indicated in the attached Figure 2. As described in the Infiltration Test Procedures section of this report, there are two complementary portions of the Small PIT test procedure utilized to determine a field infiltration rate; the steady-state period and the falling head period. In our experience, the falling head period is generally more conservative, and provides a more accurate evaluation of infiltration conditions. The results of the falling head portion of our Small PIT test is recorded below in Table 2. TABLE 2 FALLING HEAD PERIOD TEST RESULTS Test Pit Exploration Depth of Test Surface (feet) Field Infiltration Rate (in/hr) INF-1 2½ 7.25 In order to determine a design infiltration rate based upon field tests, utilizing the current SWMM, an appropriate safety factor needs to be applied to field measurements, as described in the following formula: Ksatdesign = Ksatinitial x CFT Where CFT represents the total correction factor applied to the field infiltration rate, as described below: CFT = CFv x CFt x CFm Ksatdesign is the maximum Design Infiltration Rate and Ksatinitial is the field infiltration rate determined by the Small PIT test. CFv is a safety factor that accounts for site variability and number of locations tested, with an accepted range of 0.33 to 1. The project area is relatively small, but we only performed one field test, so we believe utilizing a value of CFv = 0.45 is appropriate. CFt is a safety factor that accounts for uncertainties in the testing method and is accepted as CFt = 0.50. CFm is a safety factor which accounts for the degree of influent control to prevent siltation and bio-buildup, with an accepted value of CFm = 0.9. Under the conditions described above, we recommend applying a total correction factor of CFT = 0.20 to the field infiltration rate highlighted in Table 2. After applying the appropriate correction factor, we recommend utilizing a design infiltration rate of 1.5 inches per hour for shallow weathered/recessional outwash soils encountered on site. 3.5 Seismic Conditions Based on our analysis of subsurface exploration logs and our review of published geologic maps, we interpret the onsite soil conditions to generally correspond with site class C, as defined by Table 30.2-1 in ASCE 7, per the 2015 International Building Code (IBC). Monsef Donogh Design Group –2007 Union Ave NE, Renton, WA July 14, 2017 / Revised September 28, 2017 Geotechnical Engineering Report P1003-T17 Migizi Group, Inc. Page 6 of 14 Using 2015 IBC information on the USGS Design Summary Report website, Risk Category I/II/III seismic parameters for the site are as follows: Ss = 1.412 g SMS = 1.412 g SDS = 0.941 g S1 = 0.532 g SM1 = 0.692 g SD1 = 0.461 g Using the 2015 IBC information, MCER Response Spectrum Graph on the USGS Design Summary Report website, Risk Category I/II/III, Sa at a period of 0.2 seconds is 1.41 g and Sa at a period of 1.0 seconds is 0.69 g. The Design Response Spectrum Graph from the same website, using the same IBC information and Risk Category, Sa at a period of 0.2 seconds is 0.94 g and Sa at a period of 1.0 seconds is 0.46 g. 3.6 Liquefaction Potential Liquefaction is a sudden increase in pore water pressure and a sudden loss of soil shear strength caused by shear strains, as could result from an earthquake. Research has shown that saturated, loose, fine to medium sands with a fines (silt and clay) content less than about 20 percent are most susceptible to liquefaction. No saturated, poorly consolidated granular soils were encountered throughout the course of our test pit explorations. We interpret site soils as having a low potential of liquefying during a large-scale seismic event. 4.0 CONCLUSIONS AND RECOMMENDATIONS Improvement plans involve the demolition of existing site features, and the eventual short-plat of the subject property; resulting in three residential lots. Preliminary plans have each lot being developed, and sharing a communal driveway which travels along the northern margin of the site. Resulting lots will range from 9,676 to 12,300 sf, and will increase numerically from east to west. We offer these recommendations: • Feasibility: Based on our field explorations, research and analyses, the proposed structures appear feasible from a geotechnical standpoint. • Foundation Options: Foundation elements for the proposed residences should be constructed on medium dense or denser undisturbed native soils, or on structural fill bearing pads extending down to these soils. We anticipate that adequate bearing soils will be encountered within two to three feet of existing grade. Recommendations for Spread Footings are provided in Section 4.2. • Floor Options: Floor sections for the proposed residences should bear on medium dense or denser native soils or on properly compacted structural fill extending down to these soils. We anticipate that adequate bearing soils will be encountered within two to three feet of existing grade. Recommendations for slab-on-grade floors are included in Section 4.3. Fill underlying floor slabs should be compacted to 95 percent (ASTM:D-1557). • Pavement Sections: Native, in-situ soil conditions are amenable to the use of soil- supported pavements. We recommend a conventional pavement section comprised Monsef Donogh Design Group –2007 Union Ave NE, Renton, WA July 14, 2017 / Revised September 28, 2017 Geotechnical Engineering Report P1003-T17 Migizi Group, Inc. Page 7 of 14 of an asphalt concrete pavement over a crushed rock base course over a properly prepared (compacted) subgrade or a granular subbase, depending on subgrade conditions during pavement subgrade preparation. All soil subgrades should be thoroughly compacted, then proof-rolled with a loaded dump truck or heavy compactor. Any localized zones of yielding subgrade disclosed during this proof-rolling operation should be over-excavated to a depth of 12 inches and replaced with a suitable structural fill material. • Infiltration Conditions: Given the geological conditions encountered on site, we do not foresee full-infiltration as being feasible for this project. However, limited infiltration, utilizing a system of rain gardens, permeable pavement materials, and/or shallow trenches, likely can be implemented on site, utilizing the shallow weathered soils for stormwater retention. We recommend utilizing a design infiltration rate of 1.5 inches per hour for this soil group. A depth of 3 feet should be assumed for the contact with unweathered glacial till soils, and a minimum separation of 12 inches should be maintained from this stratum and constructed retention facilities for individual lots on site. • Geologic Hazards: During our site reconnaissance, advancement of subsurface explorations, and general evaluation of the proposed development, we did not observe any erosional, landslide, seismic, settlement, or other forms of geologic hazards within the subject property. Given this fact, we recommend that no buffers, setbacks, or other forms of site restraints be implemented to address these potential hazards. The following sections of this report present our specific geotechnical conclusions and recommendations concerning site preparation, spread footings, slab-on-grade floors, asphalt pavement, and structural fill. The Washington State Department of Transportation (WSDOT) Standard Specifications and Standard Plans cited herein refer to WSDOT publications M41-10, Standard Specifications for Road, Bridge, and Municipal Construction, and M21-01, Standard Plans for Road, Bridge, and Municipal Construction, respectively. 4.1 Site Preparation Preparation of the project site should involve erosion control, temporary drainage, clearing, stripping, excavations, cutting, subgrade compaction, and filling. Erosion Control: Before new construction begins, an appropriate erosion control system should be installed. This system should collect and filter all surface water runoff through silt fencing. We anticipate a system of berms and drainage ditches around construction areas will provide an adequate collection system. Silt fencing fabric should meet the requirements of WSDOT Standard Specification 9-33.2 Table 3. In addition, silt fencing should embed a minimum of 6 inches below existing grade. An erosion control system requires occasional observation and maintenance. Specifically, holes in the filter and areas where the filter has shifted above ground surface should be replaced or repaired as soon as they are identified. Monsef Donogh Design Group –2007 Union Ave NE, Renton, WA July 14, 2017 / Revised September 28, 2017 Geotechnical Engineering Report P1003-T17 Migizi Group, Inc. Page 8 of 14 Temporary Drainage: We recommend intercepting and diverting any potential sources of surface or near-surface water within the construction zones before stripping begins. Because the selection of an appropriate drainage system will depend on the water quantity, season, weather conditions, construction sequence, and contractor's methods, final decisions regarding drainage systems are best made in the field at the time of construction. Based on our current understanding of the construction plans, surface and subsurface conditions, we anticipate that curbs, berms, or ditches placed around the work areas will adequately intercept surface water runoff. Clearing and Stripping: After surface and near-surface water sources have been controlled, sod, topsoil, and root-rich soil should be stripped from the site. Our subsurface explorations indicate that the organic horizon can reach thicknesses of up to 12 inches. Stripping is best performed during a period of dry weather. Site Excavations: Based on our explorations, we expect deeper site excavations will predominately encounter densely consolidated glacial till soils. This soil group can be readily excavated utilizing standard excavation equipment, though special teeth, or “rippers”, may need to be utilized in order to rapidly excavate glacial till soils. Shallower excavations will encounter highly weathered, loosely consolidated soils which can be readily excavated using standard excavation equipment. Dewatering: We encountered slow seepage at a depth of ± 9½ feet in the vicinity of test pit exploration TP-1. Given the relatively depth to groundwater, and the scope of this project, we do not anticipate that groundwater will be encountered in most project excavations. However, if groundwater is encountered, we anticipate that an internal system of ditches, sump holes, and pumps will be adequate to temporarily dewater excavations. Temporary Cut Slopes: All temporary soil slopes associated with site cutting or excavations should be adequately inclined to prevent sloughing and collapse. Temporary cut slopes in site soils should be no steeper than 1½H:1V, and should conform to Washington Industrial Safety and Health Act (WISHA) regulations. Subgrade Compaction: Exposed subgrades for the foundation of the proposed residence should be compacted to a firm, unyielding state before new concrete or fill soils are placed. Any localized zones of looser granular soils observed within a subgrade should be compacted to a density commensurate with the surrounding soils. In contrast, any organic, soft, or pumping soils observed within a subgrade should be overexcavated and replaced with a suitable structural fill material. Site Filling: Our conclusions regarding the reuse of onsite soils and our comments regarding wet- weather filling are presented subsequently. Regardless of soil type, all fill should be placed and compacted according to our recommendations presented in the Structural Fill section of this report. Specifically, building pad fill soil should be compacted to a uniform density of at least 95 percent (based on ASTM:D-1557). Monsef Donogh Design Group –2007 Union Ave NE, Renton, WA July 14, 2017 / Revised September 28, 2017 Geotechnical Engineering Report P1003-T17 Migizi Group, Inc. Page 9 of 14 Onsite Soils: We offer the following evaluation of these onsite soils in relation to potential use as structural fill: • Surficial Organic Soil and Organic-Rich Fill Soils: Where encountered, surficial organic soils like duff, topsoil, root-rich soil, and organic-rich fill soils are not suitable for use as structural fill under any circumstances, due to high organic content. Consequently, this material can be used only for non-structural purposes, such as in landscaping areas. • Glacial Till: Underlying a surface mantle of sod and topsoil, native glacial till soils were encountered; generally consisting of dense, gravelly silty sand. These soils are moderately moisture sensitive and will be difficult, if not impossible, to reuse during wet weather conditions. If reuse is planned, care should be taken while stockpiling in order to avoid saturation/over-saturation of the material, and moisture conditioning should be expected. Permanent Slopes: All permanent cut slopes and fill slopes should be adequately inclined to reduce long-term raveling, sloughing, and erosion. We generally recommend that no permanent slopes be steeper than 2H:1V. For all soil types, the use of flatter slopes (such as 2½H:1V) would further reduce long-term erosion and facilitate revegetation. Slope Protection: We recommend that a permanent berm, swale, or curb be constructed along the top edge of all permanent slopes to intercept surface flow. Also, a hardy vegetative groundcover should be established as soon as feasible, to further protect the slopes from runoff water erosion. Alternatively, permanent slopes could be armored with quarry spalls or a geosynthetic erosion mat. 4.2 Spread Footings In our opinion, conventional spread footings will provide adequate support for the proposed residences if the subgrade is properly prepared. We offer the following comments and recommendations for spread footing design. Footing Depths and Widths: For frost and erosion protection, the bases of all exterior footings should bear at least 18 inches below adjacent outside grades, whereas the bases of interior footings need bear only 12 inches below the surrounding slab surface level. To reduce post-construction settlements, continuous (wall) and isolated (column) footings should be at least 16 and 24 inches wide, respectively. Bearing Subgrades: Footings should bear on medium dense or denser, undisturbed native soils which have been stripped of surficial organic soils and vigorously surface compacted, or on properly compacted structural fill bearing pads which extend down to soils described above. We anticipate that adequate bearing subgrades will be encountered within 2 to 3 feet of existing grade, within unweathered glacial till soils. In general, before footing concrete is placed, any localized zones of loose soils exposed across the footing subgrades should be compacted to a firm, unyielding condition, and any localized zones of Monsef Donogh Design Group –2007 Union Ave NE, Renton, WA July 14, 2017 / Revised September 28, 2017 Geotechnical Engineering Report P1003-T17 Migizi Group, Inc. Page 10 of 14 soft, organic, or debris-laden soils should be over-excavated and replaced with suitable structural fill. Lateral Overexcavations: Because foundation stresses are transferred outward as well as downward into the bearing soils, all structural fill placed under footings, should extend horizontally outward from the edge of each footing. This horizontal distance should be equal to the depth of placed fill. Therefore, placed fill that extends 3 feet below the footing base should also extend 3 feet outward from the footing edges. Subgrade Observation: All footing subgrades should consist of firm, unyielding, native soils, or structural fill materials that have been compacted to a density of at least 95 percent (based on ASTM:D-1557). Footings should never be cast atop loose, soft, or frozen soil, slough, debris, existing uncontrolled fill, or surfaces covered by standing water. Bearing Pressures: In our opinion, for static loading, footings that bear on moderately consolidated recessional outwash soils can be designed for a maximum allowable soil bearing pressure of 2,000 psf. A one-third increase in allowable soil bearing capacity may be used for short-term loads created by seismic or wind related activities. Footing Settlements: Assuming that structural fill soils are compacted to a medium dense or denser state, we estimate that total post-construction settlements of properly designed footings bearing on properly prepared subgrades will not exceed 1 inch. Differential settlements for comparably loaded elements may approach one-half of the actual total settlement over horizontal distances of approximately 50 feet. Footing Backfill: To provide erosion protection and lateral load resistance, we recommend that all footing excavations be backfilled on both sides of the footings and stemwalls after the concrete has cured. Either imported structural fill or non-organic onsite soils can be used for this purpose, contingent on suitable moisture content at the time of placement. Regardless of soil type, all footing backfill soil should be compacted to a density of at least 90 percent (based on ASTM:D-1557). Lateral Resistance: Footings that have been properly backfilled as recommended above will resist lateral movements by means of passive earth pressure and base friction. We recommend using an allowable passive earth pressure of 225 psf and an allowable base friction coefficient of 0.35 for site soils. 4.3 Slab-On-Grade Floors In our opinion, soil-supported slab-on-grade floors can be used in the proposed residences if the subgrades are properly prepared. Floor sections for the proposed structures should bear on medium dense or denser native soils or on properly compacted structural fill which extends down to soils described above. We anticipate that adequate bearing soils will be encountered within 2 to 3 feet of existing grade. We offer the following comments and recommendations concerning slab- on-grade floors. Monsef Donogh Design Group –2007 Union Ave NE, Renton, WA July 14, 2017 / Revised September 28, 2017 Geotechnical Engineering Report P1003-T17 Migizi Group, Inc. Page 11 of 14 Floor Subbase: Surface compaction of all slab subgrades is recommended. If a subbase is required, it should be compacted to a density of at least 95 percent (based on ASTM:D-1557). Capillary Break and Vapor Barrier: To retard the upward wicking of moisture beneath the floor slab, we recommend that a capillary break be placed over the subgrade. Ideally, this capillary break would consist of a 4-inch-thick layer of pea gravel or other clean, uniform, well-rounded gravel, such as “Gravel Backfill for Drains” per WSDOT Standard Specification 9-03.12(4), but clean angular gravel can be used if it adequately prevents capillary wicking. In addition, a layer of plastic sheeting (such as Crosstuff, Visqueen, or Moistop) should be placed over the capillary break to serve as a vapor barrier. During subsequent casting of the concrete slab, the contractor should exercise care to avoid puncturing this vapor barrier. Vertical Deflections: Due to elastic compression of subgrades, soil-supported slab-on-grade floors can deflect downwards when vertical loads are applied. In our opinion, a subgrade reaction modulus of 250 pounds per cubic inch can be used to estimate such deflections. 4.4 Asphalt Pavement Since asphalt pavements will also be used for the proposed communal driveway system, we offer the following comments and recommendations for pavement design and construction. Subgrade Preparation: All soil subgrades should be thoroughly compacted, then proof-rolled with a loaded dump truck or heavy compactor. Any localized zones of yielding subgrade disclosed during this proof-rolling operation should be over excavated to a maximum depth of 12 inches and replaced with a suitable structural fill material. All structural fill should be compacted according to our recommendations given in the Structural Fill section. Specifically, the upper 2 feet of soils underlying pavement section should be compacted to at least 95 percent (based on ASTM D-1557), and all soils below 2 feet should be compacted to at least 90 percent. Pavement Materials: For the base course, we recommend using imported washed crushed rock, such as "Crushed Surfacing Base Course” per WSDOT Standard Specification 9-03.9(3) but with a fines content of less than 5 percent passing the No. 200 Sieve. Although our explorations do not indicate a need for a pavement subbase, if a subbase course is needed, we recommend using imported, clean, well-graded sand and gravel such as “Ballast” or “Gravel Borrow” per WSDOT Standard Specifications 9-03.9(1) and 9-03.14, respectively. Conventional Asphalt Sections: A conventional pavement section typically comprises an asphalt concrete pavement over a crushed rock base course. We recommend using the following conventional pavement sections: Minimum Thickness Pavement Course Parking Areas High Traffic Driveways Asphalt Concrete Pavement 2 inches 4 inches Crushed Rock Base 4 inches 8 inches Granular Fill Subbase (if needed) 6 inches 12 inches Monsef Donogh Design Group –2007 Union Ave NE, Renton, WA July 14, 2017 / Revised September 28, 2017 Geotechnical Engineering Report P1003-T17 Migizi Group, Inc. Page 12 of 14 Compaction and Observation: All subbase and base course material should be compacted to at least 95 percent of the Modified Proctor maximum dry density (ASTM D-1557), and all asphalt concrete should be compacted to at least 92 percent of the Rice value (ASTM D-2041). We recommend that an MGI representative be retained to observe the compaction of each course before any overlying layer is placed. For the subbase and pavement course, compaction is best observed by means of frequent density testing. For the base course, methodology observations and hand-probing are more appropriate than density testing. Pavement Life and Maintenance: No asphalt pavement is maintenance-free. The above described pavement sections present our minimum recommendations for an average level of performance during a 20-year design life; therefore, an average level of maintenance will likely be required. Furthermore, a 20-year pavement life typically assumes that an overlay will be placed after about 10 years. Thicker asphalt and/or thicker base and subbase courses would offer better long-term performance, but would cost more initially; thinner courses would be more susceptible to “alligator” cracking and other failure modes. As such, pavement design can be considered a compromise between a high initial cost and low maintenance costs versus a low initial cost and higher maintenance costs. 4.5 Structural Fill The term "structural fill" refers to any material placed under foundations, retaining walls, slab-on- grade floors, sidewalks, pavements, and other structures. Our comments, conclusions, and recommendations concerning structural fill are presented in the following paragraphs. Materials: Typical structural fill materials include clean sand, gravel, pea gravel, washed rock, crushed rock, well-graded mixtures of sand and gravel (commonly called "gravel borrow" or "pit- run"), and miscellaneous mixtures of silt, sand, and gravel. Recycled asphalt, concrete, and glass, which are derived from pulverizing the parent materials, are also potentially useful as structural fill in certain applications. Soils used for structural fill should not contain any organic matter or debris, nor any individual particles greater than about 6 inches in diameter. Fill Placement: Clean sand, gravel, crushed rock, soil mixtures, and recycled materials should be placed in horizontal lifts not exceeding 8 inches in loose thickness, and each lift should be thoroughly compacted with a mechanical compactor. Compaction Criteria: Using the Modified Proctor test (ASTM:D-1557) as a standard, we recommend that structural fill used for various onsite applications be compacted to the following minimum densities: Fill Application Minimum Compaction Footing subgrade and bearing pad Foundation backfill Asphalt pavement base Asphalt pavement subgrade (upper 2 feet) Asphalt pavement subgrade (below 2 feet) 95 percent 90 percent 95 percent 95 percent 90 percent Monsef Donogh Design Group –2007 Union Ave NE, Renton, WA July 14, 2017 / Revised September 28, 2017 Geotechnical Engineering Report P1003-T17 Migizi Group, Inc. Page 13 of 14 Subgrade Observation and Compaction Testing: Regardless of material or location, all structural fill should be placed over firm, unyielding subgrades prepared in accordance with the Site Preparation section of this report. The condition of all subgrades should be observed by geotechnical personnel before filling or construction begins. Also, fill soil compaction should be verified by means of in-place density tests performed during fill placement so that adequacy of soil compaction efforts may be evaluated as earthwork progresses. Soil Moisture Considerations: The suitability of soils used for structural fill depends primarily on their grain-size distribution and moisture content when they are placed. As the "fines" content (that soil fraction passing the U.S. No. 200 Sieve) increases, soils become more sensitive to small changes in moisture content. Soils containing more than about 5 percent fines (by weight) cannot be consistently compacted to a firm, unyielding condition when the moisture content is more than 2 percentage points above or below optimum. For fill placement during wet-weather site work, we recommend using "clean" fill, which refers to soils that have a fines content of 5 percent or less (by weight) based on the soil fraction passing the U.S. No. 4 Sieve. 5.0 RECOMMENDED ADDITIONAL SERVICES Because the future performance and integrity of the structural elements will depend largely on proper site preparation, drainage, fill placement, and construction procedures, monitoring and testing by experienced geotechnical personnel should be considered an integral part of the construction process. Subsequently, we recommend that MGI be retained to provide the following post-report services: • Review all construction plans and specifications to verify that our design criteria presented in this report have been properly integrated into the design; • Prepare a letter summarizing all review comments (if required); • Check all completed subgrades for footings and slab-on-grade floors before concrete is poured, in order to verify their bearing capacity; and • Prepare a post-construction letter summarizing all field observations, inspections, and test results (if required). APPROXIMATE SITE LOCATION P.O. Box 44840 Tacoma, WA 98448 Location Job Number Figure DateTitle 2007 Union Ave NE Renton, WA P/N 0423059076 Topographic and Location Map 1 06/20/17 P1003-T17 APPENDIX A SOIL CLASSIFICATION CHART AND KEY TO TEST DATA LOG OF TEST PITS CLAYEY GRAVELS, POORLY GRADED GRAVEL-SAND-CLAY MIXTURES SILTS AND CLAYSCOARSE GRAINED SOILSMore than Half > #200 sieveLIQUID LIMIT LESS THAN 50 LIQUID LIMIT GREATER THAN 50 CLEAN GRAVELS WITH LITTLE OR NO FINES GRAVELS WITH OVER 15% FINES CLEAN SANDS WITH LITTLE OR NO FINES MORE THAN HALF COARSE FRACTION IS SMALLER THAN NO. 4 SIEVE MORE THAN HALF COARSE FRACTION IS LARGER THAN NO. 4 SIEVE INORGANIC SILTS, MICACEOUS OR DIATOMACIOUS FINE SANDY OR SILTY SOILS, ELASTIC SILTS ORGANIC CLAYS AND ORGANIC SILTY CLAYS OF LOW PLASTICITY OH INORGANIC SILTS AND VERY FINE SANDS, ROCK FLOUR, SILTY OR CLAYEY FINE SANDS, OR CLAYEY SILTS WITH SLIGHT PLASTICITY CH SILTY GRAVELS, POORLY GRADED GRAVEL-SAND-SILT MIXTURES SANDS SILTS AND CLAYS Figure A-1 INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS R-Value Sieve Analysis Swell Test Cyclic Triaxial Unconsolidated Undrained Triaxial Torvane Shear Unconfined Compression (Shear Strength, ksf) Wash Analysis (with % Passing No. 200 Sieve) Water Level at Time of Drilling Water Level after Drilling(with date measured) RV SA SW TC TX TV UC (1.2) WA (20) Modified California Split Spoon Pushed Shelby Tube Auger Cuttings Grab Sample Sample Attempt with No Recovery Chemical Analysis Consolidation Compaction Direct Shear Permeability Pocket Penetrometer CA CN CP DS PM PP PtHIGHLY ORGANIC SOILS TYPICAL NAMES GRAVELS ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SILTS WELL GRADED GRAVELS, GRAVEL-SAND MIXTURES MAJOR DIVISIONS PEAT AND OTHER HIGHLY ORGANIC SOILS WELL GRADED SANDS, GRAVELLY SANDS POORLY GRADED SANDS, GRAVELLY SANDS SILTY SANDS, POOORLY GRADED SAND-SILT MIXTURES CLAYEY SANDS, POORLY GRADED SAND-CLAY MIXTURES POORLY GRADED GRAVELS, GRAVEL-SAND MIXTURES SOIL CLASSIFICATION CHART AND KEY TO TEST DATA GW GP GM GC SW SP SM SC ML FINE GRAINED SOILSMore than Half < #200 sieveLGD A NNNN02 GINT US LAB.GPJ 11/4/05INORGANIC CLAYS OF HIGH PLASTICITY, FAT CLAYS CL OL MH SANDS WITH OVER 15% FINES Migizi Group, Inc. GB S-1 GB S-2 SM SP- SM SM SM SM 0.6 2.5 3.0 4.5 10.0 (SM) Gray/brown silty sand with gravel (loose, damp) (Fill) (SP-SM) Gray/brown fine to medium sand with silt and gravel (dense, moist) (Fill) (SM) Dark brown silty sand with some gravel and abundant organics (loose, moist) (Old Topsoil Horizon) (SM) Orange/brown fine silty sand with some gravel (medium dense, moist) (Weathered Glacial Till) (SM) Gray silty sand with gravel (dense, moist) (Unweathered Glacial Till) No caving observed Slow groundwater seepage observed at 9.5 feet The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 0.5 foot. Bottom of test pit at 10.0 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Rubber Tracked Mini Excavator EXCAVATION CONTRACTOR Paulman GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 6/27/17 COMPLETED 6/27/17 AT TIME OF EXCAVATION 9.50 ft Slow seepage AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 7.5 10.0 PAGE 1 OF 1 Figure A-2 TEST PIT NUMBER TP-1 CLIENT Monsef Donogh Design Group PROJECT NUMBER P1003-T17 PROJECT NAME Proposed Huynh 3 Lot Short Plat Geotech PROJECT LOCATION 2007 Union Ave NE, Renton, WA COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 9/28/17 14:28 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1003-T17\P1003-T17 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION GB S-1 GB S-2 SM SM SM 0.8 3.0 8.0 (SM) Gray/brown silty sand with gravel (loose, damp) (Fill) (SM) Orange/brown fine silty sand with some gravel (loose, moist) (Weathered Glacial Till) (SM) Gray silty sand with gravel (dense, moist) (Unweathered Glacial Till) No caving observed No groundwater seepage observed The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 0.5 foot. Bottom of test pit at 8.0 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Rubber Tracked Mini Excavator EXCAVATION CONTRACTOR Paulman GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 6/27/17 COMPLETED 6/27/17 AT TIME OF EXCAVATION --- AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 7.5 PAGE 1 OF 1 Figure A-3 TEST PIT NUMBER TP-2 CLIENT Monsef Donogh Design Group PROJECT NUMBER P1003-T17 PROJECT NAME Proposed Huynh 3 Lot Short Plat Geotech PROJECT LOCATION 2007 Union Ave NE, Renton, WA COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 9/28/17 14:28 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1003-T17\P1003-T17 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION GB S-1 SM SM SM 1.0 3.0 5.0 (SM) Gray/brown silty sand with gravel (loose, damp) (Fill) (SM) Orange/brown fine silty sand with some gravel (loose, moist) (Weathered Glacial Till) (SM) Gray silty sand with gravel (dense, moist) (Unweathered Glacial Till) No caving observed No groundwater seepage observed The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 0.5 foot. Bottom of test pit at 5.0 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Rubber Tracked Mini Excavator EXCAVATION CONTRACTOR Paulman GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 6/27/17 COMPLETED 6/27/17 AT TIME OF EXCAVATION --- AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 PAGE 1 OF 1 Figure A-4 TEST PIT NUMBER TP-3 CLIENT Monsef Donogh Design Group PROJECT NUMBER P1003-T17 PROJECT NAME Proposed Huynh 3 Lot Short Plat Geotech PROJECT LOCATION 2007 Union Ave NE, Renton, WA COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 9/28/17 14:28 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1003-T17\P1003-T17 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION SM SM 0.7 4.0 6.5 Sod and topsoil (SM) Light brown fine silty sand with some gravel (loose, damp) (Weathered Glacial Till) Small-Scale Pilot Infiltration Test performed at a depth of 2.5 feet (SM) Gray silty sand with gravel (dense, moist) (Unweathered Glacial Till) No caving observed No groundwater seepage observed The depths on the test pit logs are based on an average of measurements across the test pit and should be considered accurate to 0.5 foot. Bottom of test pit at 6.5 feet. NOTES LOGGED BY ZLL EXCAVATION METHOD Rubber Tracked Mini Excavator EXCAVATION CONTRACTOR Paulman GROUND WATER LEVELS: CHECKED BY JEB DATE STARTED 9/26/17 COMPLETED 9/26/17 AT TIME OF EXCAVATION --- AT END OF EXCAVATION --- AFTER EXCAVATION --- TEST PIT SIZEGROUND ELEVATION SAMPLE TYPENUMBERDEPTH(ft)0.0 2.5 5.0 PAGE 1 OF 1 Figure A-5 TEST PIT NUMBER TP-4 CLIENT Monsef Donogh Design Group PROJECT NUMBER P1003-T17 PROJECT NAME Proposed Huynh 3 Lot Short Plat Geotech PROJECT LOCATION 2007 Union Ave NE, Renton, WA COPY OF GENERAL BH / TP LOGS - FIGURE.GDT - 9/28/17 14:28 - C:\USERS\JESSICA\DESKTOP\TEST PITS AND BORINGS - GINT\P1003-T17\P1003-T17 TEST PITS.GPJMigizi Group, Inc. PO Box 44840 Tacoma, WA 98448 Telephone: 253-537-9400 Fax: 253-537-9401 U.S.C.S.GRAPHICLOGMATERIAL DESCRIPTION WWHM2012 PROJECT REPORT ___________________________________________________________________ Project Name: Eastern Basin Final Site Name: Site Address: City : Report Date: 12/11/2017 Gage : Seatac Data Start : 1948/10/01 Data End : 2009/09/30 Precip Scale: 1.17 Version Date: 2017/04/14 Version : 4.2.13 ___________________________________________________________________ Low Flow Threshold for POC 1 : 50 Percent of the 2 Year ___________________________________________________________________ High Flow Threshold for POC 1: 50 year ___________________________________________________________________ PREDEVELOPED LAND USE Name : Basin 1 Bypass: No GroundWater: No Pervious Land Use acre C, Forest, Flat .35 Pervious Total 0.35 Impervious Land Use acre Impervious Total 0 Basin Total 0.35 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater ___________________________________________________________________ MITIGATED LAND USE Name : Basin 1 Bypass: No GroundWater: No Pervious Land Use acre C, Lawn, Flat .19 Pervious Total 0.19 Impervious Land Use acre ROOF TOPS FLAT 0.04 Impervious Total 0.04 Basin Total 0.23 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater Gravel Trench Bed 1 Gravel Trench Bed 1 ___________________________________________________________________ Name : Basin 2 Bypass: Yes GroundWater: No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre ROADS MOD 0.03 DRIVEWAYS MOD 0.01 Impervious Total 0.04 Basin Total 0.04 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater ___________________________________________________________________ Name : Gravel Trench Bed 1 Bottom Length: 31.00 ft. Bottom Width: 19.00 ft. Trench bottom slope 1: 0 To 1 Trench Left side slope 0: 0 To 1 Trench right side slope 2: 0 To 1 Material thickness of first layer: 1 Pour Space of material for first layer: 0.33 Material thickness of second layer: 1 Pour Space of material for second layer: 0.33 Material thickness of third layer: 1 Pour Space of material for third layer: 0.33 Infiltration On Infiltration rate: 1.5 Infiltration safety factor: 1 Total Volume Infiltrated (ac-ft.): 7.772 Total Volume Through Riser (ac-ft.): 19.58 Total Volume Through Facility (ac-ft.): 27.352 Percent Infiltrated: 28.41 Total Precip Applied to Facility: 0 Total Evap From Facility: 0 Discharge Structure Riser Height: 3.5 ft. Riser Diameter: 10 in. Notch Type: Rectangular Notch Width: 0.833 ft. Notch Height: 1.000 ft. Orifice 1 Diameter: 3 in. Elevation: 0 ft. Element Flows To: Outlet 1 Outlet 2 ___________________________________________________________________ Gravel Trench Bed Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs) 0.0000 0.013 0.000 0.000 0.000 0.0444 0.013 0.000 0.051 0.020 0.0889 0.013 0.000 0.072 0.020 0.1333 0.013 0.000 0.089 0.020 0.1778 0.013 0.000 0.103 0.020 0.2222 0.013 0.001 0.115 0.020 0.2667 0.013 0.001 0.126 0.020 0.3111 0.013 0.001 0.136 0.020 0.3556 0.013 0.001 0.145 0.020 0.4000 0.013 0.001 0.154 0.020 0.4444 0.013 0.002 0.162 0.020 0.4889 0.013 0.002 0.170 0.020 0.5333 0.013 0.002 0.178 0.020 0.5778 0.013 0.002 0.185 0.020 0.6222 0.013 0.002 0.192 0.020 0.6667 0.013 0.003 0.199 0.020 0.7111 0.013 0.003 0.206 0.020 0.7556 0.013 0.003 0.212 0.020 0.8000 0.013 0.003 0.218 0.020 0.8444 0.013 0.003 0.224 0.020 0.8889 0.013 0.004 0.230 0.020 0.9333 0.013 0.004 0.235 0.020 0.9778 0.013 0.004 0.241 0.020 1.0222 0.013 0.004 0.246 0.020 1.0667 0.013 0.004 0.252 0.020 1.1111 0.013 0.005 0.257 0.020 1.1556 0.013 0.005 0.262 0.020 1.2000 0.013 0.005 0.267 0.020 1.2444 0.013 0.005 0.272 0.020 1.2889 0.013 0.005 0.277 0.020 1.3333 0.013 0.005 0.282 0.020 1.3778 0.013 0.006 0.286 0.020 1.4222 0.013 0.006 0.291 0.020 1.4667 0.013 0.006 0.295 0.020 1.5111 0.013 0.006 0.300 0.020 1.5556 0.013 0.006 0.304 0.020 1.6000 0.013 0.007 0.308 0.020 1.6444 0.013 0.007 0.313 0.020 1.6889 0.013 0.007 0.317 0.020 1.7333 0.013 0.007 0.321 0.020 1.7778 0.013 0.007 0.325 0.020 1.8222 0.013 0.008 0.329 0.020 1.8667 0.013 0.008 0.333 0.020 1.9111 0.013 0.008 0.337 0.020 1.9556 0.013 0.008 0.341 0.020 2.0000 0.013 0.008 0.345 0.020 2.0444 0.013 0.009 0.349 0.020 2.0889 0.013 0.009 0.353 0.020 2.1333 0.013 0.009 0.356 0.020 2.1778 0.013 0.009 0.360 0.020 2.2222 0.013 0.009 0.364 0.020 2.2667 0.013 0.010 0.367 0.020 2.3111 0.013 0.010 0.371 0.020 2.3556 0.013 0.010 0.374 0.020 2.4000 0.013 0.010 0.378 0.020 2.4444 0.013 0.010 0.381 0.020 2.4889 0.013 0.011 0.385 0.020 2.5333 0.013 0.011 0.405 0.020 2.5778 0.013 0.011 0.452 0.020 2.6222 0.013 0.011 0.514 0.020 2.6667 0.013 0.011 0.587 0.020 2.7111 0.013 0.012 0.671 0.020 2.7556 0.013 0.012 0.763 0.020 2.8000 0.013 0.012 0.864 0.020 2.8444 0.013 0.012 0.972 0.020 2.8889 0.013 0.012 1.088 0.020 2.9333 0.013 0.013 1.209 0.020 2.9778 0.013 0.013 1.337 0.020 3.0222 0.013 0.013 1.471 0.020 3.0667 0.013 0.014 1.611 0.020 3.1111 0.013 0.015 1.756 0.020 3.1556 0.013 0.015 1.906 0.020 3.2000 0.013 0.016 2.062 0.020 3.2444 0.013 0.016 2.222 0.020 3.2889 0.013 0.017 2.387 0.020 3.3333 0.013 0.018 2.556 0.020 3.3778 0.013 0.018 2.731 0.020 3.4222 0.013 0.019 2.909 0.020 3.4667 0.013 0.019 3.092 0.020 3.5111 0.013 0.020 3.243 0.020 3.5556 0.013 0.021 3.351 0.020 3.6000 0.013 0.021 3.515 0.020 3.6444 0.013 0.022 3.712 0.020 3.6889 0.013 0.022 3.924 0.020 3.7333 0.013 0.023 4.132 0.020 3.7778 0.013 0.024 4.316 0.020 3.8222 0.013 0.024 4.465 0.020 3.8667 0.013 0.025 4.572 0.020 3.9111 0.013 0.025 4.646 0.020 3.9556 0.013 0.026 4.737 0.020 4.0000 0.013 0.027 4.810 0.020 ___________________________________________________________________ ___________________________________________________________________ ANALYSIS RESULTS Stream Protection Duration ___________________________________________________________________ Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.35 Total Impervious Area:0 ___________________________________________________________________ Mitigated Landuse Totals for POC #1 Total Pervious Area:0.19 Total Impervious Area:0.08 ___________________________________________________________________ Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.013673 5 year 0.022542 10 year 0.029275 25 year 0.038684 50 year 0.046314 100 year 0.054456 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.048591 5 year 0.067896 10 year 0.082069 25 year 0.101611 50 year 0.117389 100 year 0.134244 ___________________________________________________________________ Stream Protection Duration Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.017 0.073 1950 0.020 0.068 1951 0.028 0.044 1952 0.009 0.028 1953 0.008 0.030 1954 0.011 0.040 1955 0.018 0.043 1956 0.014 0.040 1957 0.013 0.054 1958 0.013 0.035 1959 0.011 0.031 1960 0.022 0.046 1961 0.011 0.044 1962 0.007 0.030 1963 0.011 0.045 1964 0.013 0.037 1965 0.010 0.056 1966 0.009 0.032 1967 0.021 0.070 1968 0.012 0.067 1969 0.012 0.054 1970 0.010 0.046 1971 0.012 0.053 1972 0.021 0.070 1973 0.010 0.026 1974 0.011 0.053 1975 0.016 0.054 1976 0.012 0.040 1977 0.004 0.045 1978 0.010 0.047 1979 0.006 0.056 1980 0.031 0.091 1981 0.009 0.049 1982 0.021 0.081 1983 0.015 0.051 1984 0.009 0.035 1985 0.005 0.049 1986 0.023 0.043 1987 0.021 0.059 1988 0.009 0.028 1989 0.006 0.042 1990 0.059 0.128 1991 0.026 0.090 1992 0.011 0.035 1993 0.011 0.032 1994 0.004 0.026 1995 0.014 0.040 1996 0.033 0.059 1997 0.026 0.051 1998 0.009 0.042 1999 0.036 0.112 2000 0.010 0.049 2001 0.003 0.046 2002 0.014 0.072 2003 0.019 0.057 2004 0.023 0.109 2005 0.015 0.044 2006 0.015 0.041 2007 0.043 0.116 2008 0.046 0.090 2009 0.021 0.056 ___________________________________________________________________ Stream Protection Duration Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0586 0.1284 2 0.0460 0.1160 3 0.0433 0.1123 4 0.0365 0.1088 5 0.0334 0.0906 6 0.0306 0.0904 7 0.0281 0.0900 8 0.0264 0.0813 9 0.0264 0.0728 10 0.0229 0.0718 11 0.0226 0.0702 12 0.0218 0.0700 13 0.0215 0.0684 14 0.0212 0.0667 15 0.0210 0.0589 16 0.0208 0.0588 17 0.0207 0.0569 18 0.0195 0.0564 19 0.0195 0.0563 20 0.0177 0.0557 21 0.0167 0.0539 22 0.0163 0.0536 23 0.0154 0.0536 24 0.0148 0.0533 25 0.0146 0.0528 26 0.0145 0.0507 27 0.0142 0.0506 28 0.0142 0.0489 29 0.0134 0.0488 30 0.0132 0.0485 31 0.0131 0.0474 32 0.0125 0.0460 33 0.0121 0.0458 34 0.0117 0.0456 35 0.0116 0.0450 36 0.0115 0.0447 37 0.0114 0.0442 38 0.0113 0.0441 39 0.0110 0.0436 40 0.0109 0.0433 41 0.0107 0.0430 42 0.0106 0.0423 43 0.0102 0.0419 44 0.0101 0.0413 45 0.0100 0.0405 46 0.0098 0.0402 47 0.0097 0.0398 48 0.0094 0.0396 49 0.0094 0.0372 50 0.0092 0.0354 51 0.0090 0.0348 52 0.0089 0.0347 53 0.0089 0.0319 54 0.0079 0.0315 55 0.0074 0.0306 56 0.0061 0.0298 57 0.0057 0.0296 58 0.0054 0.0278 59 0.0043 0.0275 60 0.0040 0.0261 61 0.0026 0.0260 ___________________________________________________________________ Stream Protection Duration POC #1 Facility FAILED duration standard for 1+ flows. Flow(cfs) Predev Mit Percentage Pass/Fail 0.0068 18448 33153 179 Fail 0.0072 16091 29645 184 Fail 0.0076 14316 26522 185 Fail 0.0080 12694 23742 187 Fail 0.0084 11178 21359 191 Fail 0.0088 9882 19184 194 Fail 0.0092 8812 17263 195 Fail 0.0096 7835 15610 199 Fail 0.0100 7013 14202 202 Fail 0.0104 6299 12940 205 Fail 0.0108 5679 11794 207 Fail 0.0112 5172 10729 207 Fail 0.0116 4697 9824 209 Fail 0.0120 4278 8979 209 Fail 0.0124 3912 8269 211 Fail 0.0128 3527 7580 214 Fail 0.0132 3189 6941 217 Fail 0.0136 2866 6378 222 Fail 0.0140 2594 5901 227 Fail 0.0144 2353 5471 232 Fail 0.0148 2138 5052 236 Fail 0.0152 1951 4648 238 Fail 0.0156 1797 4308 239 Fail 0.0160 1670 3993 239 Fail 0.0164 1518 3683 242 Fail 0.0168 1344 3422 254 Fail 0.0172 1223 3193 261 Fail 0.0176 1123 2975 264 Fail 0.0180 1042 2787 267 Fail 0.0184 969 2588 267 Fail 0.0188 910 2415 265 Fail 0.0192 839 2265 269 Fail 0.0196 766 2141 279 Fail 0.0200 705 2022 286 Fail 0.0204 635 1909 300 Fail 0.0208 570 1810 317 Fail 0.0212 488 1723 353 Fail 0.0216 425 1624 382 Fail 0.0220 378 1528 404 Fail 0.0224 341 1450 425 Fail 0.0228 307 1378 448 Fail 0.0232 271 1317 485 Fail 0.0236 235 1274 542 Fail 0.0240 196 1205 614 Fail 0.0244 171 1140 666 Fail 0.0248 145 1082 746 Fail 0.0252 125 1033 826 Fail 0.0256 107 987 922 Fail 0.0260 95 943 992 Fail 0.0264 84 899 1070 Fail 0.0268 71 863 1215 Fail 0.0272 61 811 1329 Fail 0.0276 55 765 1390 Fail 0.0280 45 739 1642 Fail 0.0284 40 715 1787 Fail 0.0288 37 691 1867 Fail 0.0292 35 659 1882 Fail 0.0296 29 636 2193 Fail 0.0300 25 604 2416 Fail 0.0304 22 583 2650 Fail 0.0308 17 547 3217 Fail 0.0312 15 522 3480 Fail 0.0316 11 503 4572 Fail 0.0320 9 487 5411 Fail 0.0324 8 467 5837 Fail 0.0328 8 454 5675 Fail 0.0332 8 441 5512 Fail 0.0336 7 428 6114 Fail 0.0340 7 412 5885 Fail 0.0344 7 402 5742 Fail 0.0347 7 387 5528 Fail 0.0351 7 372 5314 Fail 0.0355 7 355 5071 Fail 0.0359 7 343 4900 Fail 0.0363 6 335 5583 Fail 0.0367 5 322 6440 Fail 0.0371 5 312 6240 Fail 0.0375 5 305 6100 Fail 0.0379 4 298 7450 Fail 0.0383 4 289 7225 Fail 0.0387 4 279 6975 Fail 0.0391 4 274 6850 Fail 0.0395 4 265 6625 Fail 0.0399 4 258 6450 Fail 0.0403 4 252 6300 Fail 0.0407 4 241 6025 Fail 0.0411 4 239 5975 Fail 0.0415 4 228 5700 Fail 0.0419 3 223 7433 Fail 0.0423 3 213 7100 Fail 0.0427 3 208 6933 Fail 0.0431 3 202 6733 Fail 0.0435 2 193 9650 Fail 0.0439 2 186 9300 Fail 0.0443 2 178 8900 Fail 0.0447 2 171 8550 Fail 0.0451 2 166 8300 Fail 0.0455 2 163 8150 Fail 0.0459 2 160 8000 Fail 0.0463 1 154 15400 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. ___________________________________________________________________ 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. ___________________________________________________________________ LID Report LID Technique Used for Total Volumn Volumn Infiltration Cumulative Percent Water Quality Percent Comment Treatment? Needs Through Volumn Volumn Volumn Water Quality Treatment Facility (ac-ft.) Infiltration Infiltrated Treated (ac-ft) (ac-ft) Credit Gravel Trench Bed 1 POC N 25.12 N 28.15 Total Volume Infiltrated 25.12 0.00 0.00 28.15 0.00 0% No Treat. Credit Compliance with LID Standard 8 Duration Analysis Result = Failed ___________________________________________________________________ Perlnd and Implnd Changes No changes have been made. ___________________________________________________________________ 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. 2005-2017; All Rights Reserved. WWHM2012 PROJECT REPORT ___________________________________________________________________ Project Name: West Basin Final Site Name: Site Address: City : Report Date: 12/11/2017 Gage : Seatac Data Start : 1948/10/01 Data End : 2009/09/30 Precip Scale: 1.17 Version Date: 2017/04/14 Version : 4.2.13 ___________________________________________________________________ Low Flow Threshold for POC 1 : 50 Percent of the 2 Year ___________________________________________________________________ High Flow Threshold for POC 1: 50 year ___________________________________________________________________ PREDEVELOPED LAND USE Name : Basin 1 Bypass: No GroundWater: No Pervious Land Use acre C, Forest, Flat .35 Pervious Total 0.35 Impervious Land Use acre Impervious Total 0 Basin Total 0.35 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater ___________________________________________________________________ MITIGATED LAND USE Name : Basin 1 Bypass: No GroundWater: No Pervious Land Use acre C, Lawn, Mod .33 Pervious Total 0.33 Impervious Land Use acre ROOF TOPS FLAT 0.1 Impervious Total 0.1 Basin Total 0.43 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater Gravel Trench Bed 1 Gravel Trench Bed 1 ___________________________________________________________________ Name : Gravel Trench Bed 1 Bottom Length: 104.00 ft. Bottom Width: 27.00 ft. Trench bottom slope 1: 0 To 1 Trench Left side slope 0: 0 To 1 Trench right side slope 2: 0 To 1 Material thickness of first layer: 1 Pour Space of material for first layer: 0.33 Material thickness of second layer: 1 Pour Space of material for second layer: 0.33 Material thickness of third layer: 1 Pour Space of material for third layer: 0.33 Infiltration On Infiltration rate: 1.5 Infiltration safety factor: 1 Wetted surface area On Total Volume Infiltrated (ac-ft.): 33.936 Total Volume Through Riser (ac-ft.): 17.931 Total Volume Through Facility (ac-ft.): 51.868 Percent Infiltrated: 65.43 Total Precip Applied to Facility: 0 Total Evap From Facility: 0 Discharge Structure Riser Height: 3.5 ft. Riser Diameter: 10 in. Notch Type: Rectangular Notch Width: 0.833 ft. Notch Height: 1.000 ft. Orifice 1 Diameter: 3 in. Elevation: 0 ft. Element Flows To: Outlet 1 Outlet 2 ___________________________________________________________________ Gravel Trench Bed Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs) 0.0000 0.064 0.000 0.000 0.000 0.0444 0.064 0.000 0.051 0.097 0.0889 0.064 0.001 0.072 0.097 0.1333 0.064 0.002 0.089 0.097 0.1778 0.064 0.003 0.103 0.097 0.2222 0.064 0.004 0.115 0.097 0.2667 0.064 0.005 0.126 0.097 0.3111 0.064 0.006 0.136 0.097 0.3556 0.064 0.007 0.145 0.097 0.4000 0.064 0.008 0.154 0.097 0.4444 0.064 0.009 0.162 0.097 0.4889 0.064 0.010 0.170 0.097 0.5333 0.064 0.011 0.178 0.097 0.5778 0.064 0.012 0.185 0.097 0.6222 0.064 0.013 0.192 0.097 0.6667 0.064 0.014 0.199 0.097 0.7111 0.064 0.015 0.206 0.097 0.7556 0.064 0.016 0.212 0.097 0.8000 0.064 0.017 0.218 0.097 0.8444 0.064 0.018 0.224 0.097 0.8889 0.064 0.018 0.230 0.097 0.9333 0.064 0.019 0.235 0.097 0.9778 0.064 0.020 0.241 0.097 1.0222 0.064 0.021 0.246 0.097 1.0667 0.064 0.022 0.252 0.097 1.1111 0.064 0.023 0.257 0.097 1.1556 0.064 0.024 0.262 0.097 1.2000 0.064 0.025 0.267 0.097 1.2444 0.064 0.026 0.272 0.097 1.2889 0.064 0.027 0.277 0.097 1.3333 0.064 0.028 0.282 0.097 1.3778 0.064 0.029 0.286 0.097 1.4222 0.064 0.030 0.291 0.097 1.4667 0.064 0.031 0.295 0.097 1.5111 0.064 0.032 0.300 0.097 1.5556 0.064 0.033 0.304 0.097 1.6000 0.064 0.034 0.308 0.097 1.6444 0.064 0.035 0.313 0.097 1.6889 0.064 0.035 0.317 0.097 1.7333 0.064 0.036 0.321 0.097 1.7778 0.064 0.037 0.325 0.097 1.8222 0.064 0.038 0.329 0.097 1.8667 0.064 0.039 0.333 0.097 1.9111 0.064 0.040 0.337 0.097 1.9556 0.064 0.041 0.341 0.097 2.0000 0.064 0.042 0.345 0.097 2.0444 0.064 0.043 0.349 0.097 2.0889 0.064 0.044 0.353 0.097 2.1333 0.064 0.045 0.356 0.097 2.1778 0.064 0.046 0.360 0.097 2.2222 0.064 0.047 0.364 0.097 2.2667 0.064 0.048 0.367 0.097 2.3111 0.064 0.049 0.371 0.097 2.3556 0.064 0.050 0.374 0.097 2.4000 0.064 0.051 0.378 0.097 2.4444 0.064 0.052 0.381 0.097 2.4889 0.064 0.052 0.385 0.097 2.5333 0.064 0.053 0.405 0.097 2.5778 0.064 0.054 0.452 0.097 2.6222 0.064 0.055 0.514 0.097 2.6667 0.064 0.056 0.587 0.097 2.7111 0.064 0.057 0.671 0.097 2.7556 0.064 0.058 0.763 0.097 2.8000 0.064 0.059 0.864 0.097 2.8444 0.064 0.060 0.972 0.097 2.8889 0.064 0.061 1.088 0.097 2.9333 0.064 0.062 1.209 0.097 2.9778 0.064 0.063 1.337 0.097 3.0222 0.064 0.066 1.471 0.097 3.0667 0.064 0.069 1.611 0.097 3.1111 0.064 0.071 1.756 0.097 3.1556 0.064 0.074 1.906 0.097 3.2000 0.064 0.077 2.062 0.097 3.2444 0.064 0.080 2.222 0.097 3.2889 0.064 0.083 2.387 0.097 3.3333 0.064 0.086 2.556 0.097 3.3778 0.064 0.089 2.731 0.097 3.4222 0.064 0.092 2.909 0.097 3.4667 0.064 0.094 3.092 0.097 3.5111 0.064 0.097 3.243 0.097 3.5556 0.064 0.100 3.351 0.097 3.6000 0.064 0.103 3.515 0.097 3.6444 0.064 0.106 3.712 0.097 3.6889 0.064 0.109 3.924 0.097 3.7333 0.064 0.112 4.132 0.097 3.7778 0.064 0.114 4.316 0.097 3.8222 0.064 0.117 4.465 0.097 3.8667 0.064 0.120 4.572 0.097 3.9111 0.064 0.123 4.646 0.097 3.9556 0.064 0.126 4.737 0.097 4.0000 0.064 0.129 4.810 0.097 ___________________________________________________________________ Name : Basin 2 Bypass: Yes GroundWater: No Pervious Land Use acre Pervious Total 0 Impervious Land Use acre ROADS MOD 0.04 DRIVEWAYS MOD 0.01 Impervious Total 0.05 Basin Total 0.05 ___________________________________________________________________ Element Flows To: Surface Interflow Groundwater ___________________________________________________________________ ___________________________________________________________________ ANALYSIS RESULTS Stream Protection Duration ___________________________________________________________________ Predeveloped Landuse Totals for POC #1 Total Pervious Area:0.35 Total Impervious Area:0 ___________________________________________________________________ Mitigated Landuse Totals for POC #1 Total Pervious Area:0.33 Total Impervious Area:0.15 ___________________________________________________________________ Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.012456 5 year 0.019876 10 year 0.0247 25 year 0.030539 50 year 0.034665 100 year 0.03859 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.035429 5 year 0.047809 10 year 0.056843 25 year 0.069248 50 year 0.079233 100 year 0.089877 ___________________________________________________________________ Stream Protection Duration Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1949 0.013 0.035 1950 0.025 0.068 1951 0.028 0.039 1952 0.009 0.026 1953 0.007 0.026 1954 0.010 0.033 1955 0.017 0.034 1956 0.015 0.033 1957 0.013 0.040 1958 0.013 0.034 1959 0.010 0.025 1960 0.020 0.034 1961 0.010 0.030 1962 0.007 0.028 1963 0.010 0.030 1964 0.010 0.034 1965 0.009 0.029 1966 0.008 0.030 1967 0.017 0.045 1968 0.010 0.050 1969 0.011 0.027 1970 0.009 0.030 1971 0.009 0.029 1972 0.021 0.047 1973 0.010 0.026 1974 0.010 0.033 1975 0.016 0.043 1976 0.010 0.028 1977 0.002 0.030 1978 0.009 0.043 1979 0.005 0.041 1980 0.015 0.040 1981 0.008 0.041 1982 0.019 0.061 1983 0.013 0.037 1984 0.009 0.032 1985 0.005 0.026 1986 0.022 0.040 1987 0.020 0.047 1988 0.008 0.020 1989 0.005 0.027 1990 0.031 0.071 1991 0.026 0.062 1992 0.009 0.031 1993 0.010 0.019 1994 0.003 0.022 1995 0.014 0.030 1996 0.026 0.043 1997 0.025 0.040 1998 0.006 0.041 1999 0.016 0.085 2000 0.010 0.039 2001 0.002 0.028 2002 0.013 0.040 2003 0.010 0.038 2004 0.025 0.079 2005 0.013 0.030 2006 0.016 0.029 2007 0.042 0.088 2008 0.035 0.061 2009 0.019 0.038 ___________________________________________________________________ Stream Protection Duration Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0415 0.0875 2 0.0348 0.0848 3 0.0308 0.0787 4 0.0275 0.0705 5 0.0263 0.0683 6 0.0258 0.0623 7 0.0255 0.0614 8 0.0252 0.0609 9 0.0248 0.0495 10 0.0219 0.0472 11 0.0214 0.0466 12 0.0202 0.0453 13 0.0201 0.0433 14 0.0190 0.0432 15 0.0187 0.0426 16 0.0173 0.0411 17 0.0172 0.0411 18 0.0163 0.0406 19 0.0162 0.0401 20 0.0156 0.0401 21 0.0151 0.0399 22 0.0149 0.0398 23 0.0136 0.0396 24 0.0133 0.0390 25 0.0131 0.0387 26 0.0130 0.0383 27 0.0128 0.0377 28 0.0127 0.0375 29 0.0126 0.0354 30 0.0109 0.0344 31 0.0105 0.0338 32 0.0104 0.0337 33 0.0103 0.0336 34 0.0103 0.0333 35 0.0102 0.0332 36 0.0102 0.0329 37 0.0102 0.0319 38 0.0102 0.0306 39 0.0101 0.0305 40 0.0098 0.0300 41 0.0096 0.0299 42 0.0096 0.0298 43 0.0095 0.0297 44 0.0094 0.0297 45 0.0093 0.0296 46 0.0092 0.0290 47 0.0091 0.0290 48 0.0090 0.0288 49 0.0086 0.0279 50 0.0082 0.0278 51 0.0082 0.0277 52 0.0079 0.0274 53 0.0074 0.0267 54 0.0067 0.0260 55 0.0063 0.0260 56 0.0054 0.0259 57 0.0048 0.0256 58 0.0047 0.0249 59 0.0033 0.0215 60 0.0022 0.0202 61 0.0019 0.0188 ___________________________________________________________________ Stream Protection Duration POC #1 Facility FAILED duration standard for 1+ flows. Flow(cfs) Predev Mit Percentage Pass/Fail 0.0062 4766 11315 237 Fail 0.0065 4282 10486 244 Fail 0.0068 3917 9727 248 Fail 0.0071 3584 9037 252 Fail 0.0074 3270 8427 257 Fail 0.0077 2968 7855 264 Fail 0.0080 2711 7331 270 Fail 0.0082 2505 6818 272 Fail 0.0085 2309 6331 274 Fail 0.0088 2116 5909 279 Fail 0.0091 1937 5540 286 Fail 0.0094 1791 5203 290 Fail 0.0097 1645 4852 294 Fail 0.0100 1533 4529 295 Fail 0.0102 1423 4265 299 Fail 0.0105 1319 4008 303 Fail 0.0108 1239 3777 304 Fail 0.0111 1142 3542 310 Fail 0.0114 1072 3362 313 Fail 0.0117 999 3150 315 Fail 0.0120 931 2968 318 Fail 0.0123 861 2809 326 Fail 0.0125 805 2625 326 Fail 0.0128 750 2482 330 Fail 0.0131 703 2363 336 Fail 0.0134 656 2222 338 Fail 0.0137 609 2117 347 Fail 0.0140 572 2002 350 Fail 0.0143 533 1898 356 Fail 0.0146 504 1789 354 Fail 0.0148 476 1670 350 Fail 0.0151 446 1585 355 Fail 0.0154 417 1503 360 Fail 0.0157 398 1428 358 Fail 0.0160 356 1354 380 Fail 0.0163 330 1286 389 Fail 0.0166 311 1235 397 Fail 0.0169 294 1174 399 Fail 0.0171 280 1113 397 Fail 0.0174 264 1046 396 Fail 0.0177 253 995 393 Fail 0.0180 239 950 397 Fail 0.0183 226 902 399 Fail 0.0186 217 853 393 Fail 0.0189 203 810 399 Fail 0.0192 189 773 408 Fail 0.0194 176 744 422 Fail 0.0197 165 712 431 Fail 0.0200 154 689 447 Fail 0.0203 143 645 451 Fail 0.0206 131 622 474 Fail 0.0209 120 600 500 Fail 0.0212 110 567 515 Fail 0.0215 102 548 537 Fail 0.0217 97 519 535 Fail 0.0220 88 505 573 Fail 0.0223 83 486 585 Fail 0.0226 76 457 601 Fail 0.0229 70 439 627 Fail 0.0232 60 426 710 Fail 0.0235 57 414 726 Fail 0.0237 48 404 841 Fail 0.0240 45 388 862 Fail 0.0243 41 376 917 Fail 0.0246 39 357 915 Fail 0.0249 36 337 936 Fail 0.0252 31 324 1045 Fail 0.0255 27 319 1181 Fail 0.0258 25 306 1224 Fail 0.0260 23 294 1278 Fail 0.0263 21 281 1338 Fail 0.0266 19 276 1452 Fail 0.0269 16 268 1675 Fail 0.0272 15 260 1733 Fail 0.0275 14 252 1800 Fail 0.0278 11 244 2218 Fail 0.0281 10 236 2360 Fail 0.0283 10 227 2270 Fail 0.0286 8 223 2787 Fail 0.0289 8 220 2750 Fail 0.0292 7 213 3042 Fail 0.0295 7 207 2957 Fail 0.0298 6 191 3183 Fail 0.0301 6 180 3000 Fail 0.0304 4 174 4350 Fail 0.0306 4 166 4150 Fail 0.0309 3 162 5400 Fail 0.0312 2 155 7750 Fail 0.0315 2 153 7650 Fail 0.0318 2 147 7350 Fail 0.0321 2 144 7200 Fail 0.0324 2 138 6900 Fail 0.0327 2 135 6750 Fail 0.0329 2 130 6500 Fail 0.0332 2 126 6300 Fail 0.0335 2 121 6050 Fail 0.0338 2 115 5750 Fail 0.0341 2 110 5500 Fail 0.0344 2 108 5400 Fail 0.0347 2 105 5250 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. ___________________________________________________________________ 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. ___________________________________________________________________ LID Report LID Technique Used for Total Volumn Volumn Infiltration Cumulative Percent Water Quality Percent Comment Treatment? Needs Through Volumn Volumn Volumn Water Quality Treatment Facility (ac-ft.) Infiltration Infiltrated Treated (ac-ft) (ac-ft) Credit Total Volume Infiltrated 0.00 0.00 0.00 0.00 0.00 0% No Treat. Credit Compliance with LID Standard 8 Duration Analysis Result = Passed ___________________________________________________________________ Perlnd and Implnd Changes No changes have been made. ___________________________________________________________________ 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. 2005-2017; All Rights Reserved.