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HomeMy WebLinkAboutMisc 2 of 2REPORT OF GEOTECHNICAL ENGINEERING SERVICES Vantage Point -Multi-Family Rental Project Vantage Glen Community 17901 105'" Place SE Renton, Washington For Vantage Point Apartments LLC c/o King County Housing Authority February 1 8, 201 4 GeoDesign Project: KCHA-29-03 DRAFT RECEIVED FEB 2 J 2014 C(YY OF J;i?\'TON i-:LA1\JNJNG 0/\P','C'\J ,,, I ( February 18, 2014 Vantage Point Apartments LLC c/o King County Housing Authority Capital Construction Department 62 5 Andover Park West, Suite l 07 Seattle, WA 98188 Attention: Mr. Tim Locke DRAFT Report of Geotechnical Engineering Services Vantage Point -Multi-Family Rental Project Vantage Glen Community 17901 105'" Place SE Renton, Washington GeoDesign Project: KCHA-29-03 GeoDesign, Inc. is pleased to submit this report that summarizes our geotechnical engineering services to support the development of multi-family housing at the Vantage Glen Community in Renton, Washington. This report has been prepared in accordance with discussions, our proposal dated November l 5, 2013, and in conjunction with our report entitled Report of Geotechnical Engineering Services; Vantage Glen -Multi-Family Rental Project; Vantage Glen; I 790 I I 05"' Place SE; Renton, Washington, dated March 21, 201 3. • • • DRAFT We appreciate the opportunity to be of service to you. Please contact us if you have questions regarding this report. Sincerely, GeoDesign, Inc. [DRAFT] Thomas A Tobin, P.E. Principal Engineer cc: Ms. Pam Derry, Tonkin/Hoyne Architecture & Urban Design (via email only) Mr. Alberto Cisneros, KPFF Consulting Engineers (via email only) Ms. Anna Nelson, Van Ness Feldman LLP (via email only) TAP:TAT:kt Attachments One copy submitted (via email only) Document ID: KCHA-29-03-021814-geor-DRAFT.docx © 2014 GeoDesign, Inc. All rights reserved. 2 KCHA-29-03:021814 TABLE OF CONTENTS 1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 INTRODUCTION PURPOSE AND SCOPE OF WORK SITE CONDITIONS 3.1 3.2 3.3 General Surface Conditions Subsurface Conditions 3.4 Groundwater INFILTRATION TESTING LABORATORY TESTING DESIGN RECOMMENDATIONS 6. 1 General 6.2 Seismic Design Criteria 6.3 Foundation Support -Shallow Spread Footings 6.4 Concrete Slab on Grade 6.5 Below-Grade Walls and Retaining Walls 6.6 Stormwater Infiltration Evaluation 6. 7 Pavement Design SEWER IN STEEP SLOPE AREA 7. 1 7.2 7.3 Slope Topography Subsurface Soils Sewer Pipeline Recommendations 7.4 Erosion Protection SITE DEVELOPMENT 8.1 8.2 8.3 8.4 8.5 Site Preparation Excavation Fill Materials Geosynthetics Construction Stormwater Considerations 8.6 Wet Weather Considerations 9.0 OBSERVATION OF CONSTRUCTION 10.0 LIMITATIONS REFERENCES FIGURES Vicinity Map Site Plan 1985 Aerial Photograph of Vantage Glen Site Site Area Modified by Previous Legal Grading Existing Steep Slope and Erosion Hazard Areas New Steep Slope and Erosion Hazard Areas rfflDESIGNi DRAFT PAGE NO. 1 2 2 2 3 4 4 4 5 5 6 7 9 10 12 13 19 19 20 20 22 23 23 25 25 27 28 28 29 30 31 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 KCHA-29-03:021814 TABLE OF CONTENTS APPENDICES Appendix A Field Explorations Laboratory Testing Exploration Key Soil Classification System Boring Logs Grain-Size Test Results Summary of Laboratory Data Appendix B Prior Exploration Logs Appendix C Analytical Resources, Inc. Laboratory Report ACRONYMS (i1RDES1GN2 DRAFT PAGE NO. A-1 A-1 Table A-1 Table A-2 Figures A-1 -A-5 Figure A-6 Figure A-7 KCHA-29-03:021814 DRAFT l.O INTRODUCTION This report presents the results of GeoDesign's geotechnical engineering services for the development of multi-family housing at the Vantage Glen Community in Renton, Washington. The Vantage Glen Community is located south and west of the intersection of SE 1 SO'h Street and 1 05'h Place SE. The existing Vantage Glen Community consists of single-family manufactured homes and a community center. We understand the proposed development will be multi-family housing. As currently planned, the housing will include the construction of multi-story apartments and associated infrastructure (parking and utilities). We understand that significant site grading is anticipated to include excavations for below-grade parking under the buildings and construction of a stormwater management pond. Our proposal was submitted to KCHA on November 1 5, 2013 and subsequently approved by contract number CD1100165, Task Order Number 18, dated November 25, 2013. Our initial geotechnical report was submitted to KCHA on March 21, 2013. This updated report is issued to provide additional recommendations for new and/or revised project considerations that have arisen as the project design evolved. We also updated the Geologic Hazards Report for the project. The original report was issued on February 27, 2013; the updated report was issued on January 16, 2014. For your reference, definitions of all acronyms used herein are defined at the end of this document. 2.0 PURPOSE AND SCOPE OF WORK The purpose of this study was to complete additional subsurface explorations and provide additional geotechnical recommendations for the final design phase. Our scope of work included conducting a site reconnaissance, drilling and sampling five exploratory borings, performing laboratory testing, and completing engineering analyses to develop the geotechnical conclusions and recommendations presented in this report. Specifically, we performed the following: • Collected and reviewed readily available geotechnical and geological data for the project area. • Reviewed our existing report, including historical aerial photographs of the site, to identify areas where historical grading or mining has taken place and to identify slopes created by those activities. • Coordinated and managed the field investigation, including public utility locates and scheduling of contractors and GeoDesign staff. RDESIGNi KCHA-29-03:021814 DRAFT • Completed the following explorations to evaluate the subsurface conditions at the site: • Five additional borings to depths ofup to 61.5 feet BG5 o Performed infiltration tests in the augers at the approximate elevation of the base of the pond o Installed a well to a depth of 60 feet BGS to monitor high groundwater levels during the wet season • Completed laboratory analyses on selected disturbed soil samples obtained from the explorations to determine certain index properties of the on-site soil. • Performed engineering analyses and evaluated data derived from the subsurface investigation and laboratory testing program. • Prepared this report summarizing our findings, conclusions, and recommendations related to the following: • Subsurface soil and groundwater conditions and results of laboratory testing • Estimate of preliminary infiltration rates for design ofthe infiltration pond, including laboratory testing to evaluate water quality treatment capacity of native soils based on CEC and organic matter content testing • Groundwater mounding analysis to determine the effect of the infiltration pond on the surrounding properties • Slope analysis with post-pond groundwater levels • Waterproofing recommendation for the below-grade parking basement walls • Hillside pipeline recommendations • Underslab drainage recommendations • Grasscrete pavement evaluation GeoDesign's scope of work did not include environmental assessments or evaluations regarding the presence or absence of wetlands or hazardous substances in the soil, surface water, or groundwater at this site. 3.0 SITE CONDITIONS 3.1 GENERAL The Vantage Glen Community is located south and west of the intersection of SE 180'" Street and l 05'" Place SE. The proposed multi-family housing project site includes the two adjoining undeveloped parcels to the north and the east of the existing communities (parcel numbers 3223059363 and 3223059362). The two parcels form an "L" shape (approximately 5 acres in size), a portion of which is bordered by l 80'" Avenue SE to the north and l 05'" Place SE to the east, an apartment complex on the north, and by the KCHA Vantage Glen residential community on the west and south. Surficial conditions were determined from observations during several visits to the site. Subsurface conditions throughout the site were evaluated by completing our explorations. 3.2 SURFACE CONDITIONS The site is located on a slope that ascends gradually upwards from SE 180'" Street and l 05'" Place SE to a ridge that generally defines the western and southern boundary between the two undeveloped parcels. West and south of the ridge, the ground descends steeply down to the 2 KCHA-29-03:021814 DRAFT backyards of the Vantage Glen Community homes on 104" Avenue SE and SE 181" Street. The slope gradients in this area vary from 40 percent to approximately 60 percent, with a change in elevation varying from 30 to 45 feet, and the slope meets the definition for steep slope geologic hazard areas as defined by the King County land use codes. We concluded that the Vantage Glen property and surrounding undeveloped parcels owned by KCHA have been extensively graded during past aggregate mining activities on the property and that the slopes were created as a result of mining activity. 3.3 SUBSURFACE CONDITIONS Subsurface conditions were explored within the proposed development area by drilling four borings during the initial phase of work at the site conducted during February 2013. We also completed 11 test pits during the initial phase. Those borings and test pits were documented in our March 21, 2013 report and are included herein for completeness. The recent explorations included drilling five additional borings (B-S through B-9) to depths ranging between 16.5 and 61.5 feet BGS in December 2013. Borings B-5 through B-7 were completed in the area of the proposed infiltration pond. Initially, the borings were drilled to a depth of 12.0 feet BGS where infiltration tests were performed. The borings continued to a depth of 31.S feet BGS in B-5 and B-7 and to 61.5 feet BGS in boring B-6. Borings B-8 and B-9 were completed along the slope on the western portion of the site. The exploration locations are shown on Figure 2. Descriptions of the field explorations, exploration logs, and laboratory procedures for the additional explorations are included in Appendix A of this report. Exploration logs for the initial phase of work are presented in Appendix B. Subsurface conditions encountered at the boring locations are generally consistent with the subsurface conditions described in our report dated March 21, 2013. The soils encountered in the bottom of the pond and along the western slope are described below. 3.3.1 Infiltration Pond Unengineered fill was encountered in the borings located in the pond area to a depth of approximately 1 foot BGS. The fill generally consist of silt with varying amounts of sand, gravel, and construction debris and silty sand with minor gravel. Beneath the fill, native soil was encountered. The native soil consists of intermixed sand, silt, and small amounts of gravel that were deposited by glaciers. The sand is medium dense to very dense and the silt is stiff to very stiff or hard. 3.3.2 Western Slope The soil along the slope on the western side of the site consists of sand with varying amounts of silt and sandy silt with varying amounts of gravel. The sand is dense to very dense and the sandy silt encountered in the upper 8 feet of B-8 is stiff. DDESIGNt 3 KCHA-29-03:021814 DRAFT 3.4 GROUNDWATER Groundwater was encountered in boring B-6 at approximately 45 feet BGS during drilling. A well was installed to a depth of 60.0 feet BGS. The groundwater level datalogger was installed in the well so that water levels can be obtained throughout the wet season to determine the seasonal high groundwater level. 4.0 INFILTRATION TESTING Infiltration testing was performed at the three borings in the pond area. The testing was completed in general accordance with the EPA falling head percolation test procedure provided in the King County 2009 SWDM (King County, 2009). The tests were performed at a depth of approximately 1 2 feet BGS or the approximate depth of the infiltration facility. Several tests were completed at each location after the saturation period. The test results are presented in Appendix C. 5.0 LABORATORY TESTING Laboratory tests were conducted on specific soil samples selected from the explorations to assist in characterizing certain physical parameters of the soil. Index tests that were performed included the determination of natural water content and grain-size distribution determinations. These tests were performed in GeoDesign's accredited soils laboratory. All tests were conducted in general accordance with appropriate ASTM standards (ASTM, 2011 ). A discussion of laboratory test methodology and test results are presented in Appendix A. Test results are also displayed where appropriate on the exploration logs in Appendix A. CEC and organic matter tests were completed on samples located at or near the anticipated base of the infiltration facility to evaluate soil capacity for water quality treatment. The CEC tests and organic matter tests were performed by Analytical Resources, Inc. A summary of test results is provided in Table 1. The test results are presented in Appendix B. Table 1. Soil Analytical Results Summary ' Boring Sample Depth CEC' Organic Content (feet BGS) (meq per l 00 grams) (percent) B-5 1 5.0 8.6 0.7 8-6 1 5.0 7.4 0.6 8-7 1 5.0 7.7 0.9 1. Suitability for Water Quality Treatment: CEC greater than 5 meq per 100 grams and organic matter content a minimum of 0.5 percent (King County, 2009) 4 KCHA-29-03:021814 DRAFT 6.0 DESIGN RECOMMENDATIONS 6.1 GENERAL Based on our review of available information; the development history of the site; and the results of our explorations, laboratory testing, and analyses, it is our opinion that the site is suitable for construction of the proposed multi-family housing project and associated improvements. The following are key considerations for this development: • The Puget Sound area is a seismically active region. The dense, glacially consolidated material underlying the site at depths below l 0.0 to l 5.0 feet BGS is not conducive to amplifying earthquake ground motions and is not susceptible to liquefaction or lateral spreading. We did not observe evidence of faults on the site in the explorations or on geologic maps of the area and have concluded that the probability of surface rupture is low. We have provided appropriate seismic design recommendations based on the 2012 IBC criteria. • Fill that is unengineered was encountered over much of the site. The fill is less than 5 feet thick over much of the site; however, it ranges to as much as l 3 feet thick in the area west of the intersection of SE l 80'" Street and l 05'" Place SE. The fill frequently contains some localized demolition rubble and debris. This fill is not suitable for direct support of the structures and must be removed and replaced with compacted structural fill for adequate building support. Alternatively, the fill could be penetrated with an intermediate subsurface ground improvement system (such as rammed aggregate piers or stone columns) to provide adequate support for the building foundations and slabs-on-grade. The fill can remain in place outside of the building areas. • Where deeper fill is not present, shallow spread footing foundations bearing on an improved subgrade, prepared as recommended in the "Foundation Support -Shallow Spread Footings" section of this report, will provide adequate support for the proposed buildings. • The building floor slab can be supported on grade, provided the subgrade is prepared as recommended in the "Concrete Slab on Grade" section of this report. • We recommend installing an underslab drainage collection and discharge system below the slabs. The underslab drainage system should consist of at least 12 inches of 1.5-inch-minus clean crushed gravel with negligible sand or silt (WSS 9-03. l (4)C, Grading, No. 57). The gravel layer should be placed between deepened foundation elements or below the slab/mat foundations, but should not be placed below the deepened foundation elements. • Retaining walls will be required to support the west margin of the Grasscrete access road around the west side of the building and at other locations where grade transitions cannot be sloped. Recommendations are presented for MSE walls and concrete cantilever retaining walls. rfflDESIGNz 5 KCHA-29-03:021814 • Sufficient separation of more than S feet exists between the anticipated bottom of the infiltration pond and the groundwater table and confining layers. The separation is necessary to support infiltration and avoid groundwater mounding. DRAFT • Soil exposed at the anticipated base of the infiltration pond will consist of sandy silt interbedded with silty sand. We recommend a design long-term infiltration rate of 0.4 inch per hour for design of the infiltration pond. • The soil below the base of the infiltration pond meets the soil suitability criteria for stormwater treatment. The King County 2009 SWDM soil suitability criteria requires a CEC of at least 5 meq per 100 grams and an organic content of at least 0.5 percent. • Both traditional HMA and pervious HMA pavements are planned for this project. Recommendations are presented for the following pavement sections. • Traditional HMA pavement will be used to construct the access driveways and the drive aisles in the parking areas. • Pervious HMA will be used in the parking stall areas. • A perimeter emergency access road around the west and south sides of the main building will be surfaced with Grasscrete. • A perimeter emergency access road around the west and south sides of the main building will be surfaced with Grasscrete. A summary of our evaluation of the Grasscrete pavement is included in this report. • Recommendations for the construction of the sewer in the steep slope are presented. Recommendations include site preparation, pipe construction, erosion control, and securing and bedding recommendations. We are currently finalizing our evaluation of groundwater mounding at the stormwater infiltration pond site. The results of the mounding analysis will be included in our final report. Our specific recommendations for design and guidelines for development of the site are presented in the following sections of this report. These should be incorporated into design and implemented during construction of the proposed development. 6.2 SEISMIC DESIGN CRITERIA Moderate to high levels of earthquake shaking should be anticipated during the design life of the building, and it should be designed to resist earthquake loading in accordance with the methodology described in the 2012 IBC. The recommended seismic design parameters for the proposed residential buildings, based on the 201 2 IBC, are presented in Table 2. nDES1cN,, 6 KCHA-29-03:021814 DRAFT Table 2. IBC Seismic Design Parameters Seismic Design Parameter Short Period I ·Second Period MCE Spectral Acceleration s = • 1.393 g s, =0.519g Site Class C Site Coefficient F = 1 F, = 1.364 • Adjusted Spectral Acceleration s .. = 1.393 g s., = 0.675 g Design Spectral Response Acceleration Parameters sos= 0.929 s,, = 0.450 g 6.3 FOUNDATION SUPPORT -SHALLOW SPREAD FOOTINGS 6.3.1 General Conventional shallow spread footings will provide adequate support for the anticipated building loads. Loose to medium dense and/or soft to very stiff fill was typically encountered to depths ranging between 1.0 and 13.0 feet BGS. Laboratory tests indicate that the moisture content of the fill is significantly above the optimum moisture content. Subgrade improvement measures that consist of over-excavation and replacement of a portion of the unengineered fill below foundation elements will be necessary to provide adequate foundation support. We recommend fully over-excavating the existing fill and re-compacting the material as structural fill. Any rubble or debris should be removed from the fill material prior to replacing it as structural fill. The structural fill should be placed in lifts with a maximum uncompacted thickness of 12 inches and compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1 557. 6.3.2 Dimensions and Capacities Continuous and isolated spread footings should be at least 18 and 24 inches wide, respectively. The bottom of exterior footings should be at least l 8 inches below the adjacent exterior grade for frost heave protection. Interior footings should be founded a minimum of 12 inches below the lowest adjacent soil grade. Foundations supported on the properly prepared subgrade may be designed for an allowable bearing pressure of 3,500 psf. This is a net bearing pressure; the weight of the footing and overlying backfill can be ignored in calculating footing sizes. The recommended allowable bearing pressure applies to the total of dead plus long-term live loads and may be increased by one-third to account for short-term live loads such as induced by wind or seismic forces. 6.3.3 Resistance to Sliding Wind, earthquakes, and unbalanced earth loads will subject the proposed buildings to lateral forces. Lateral loads on footings can be resisted by passive earth pressure on the sides of the buried portions of the foundations and by friction on the base of the footings. An allowable passive resistance may be calculated as a triangular equivalent fluid pressure distribution using DDESIGN, 7 KCHA-29-03:021814 DRAFT an equivalent fluid density of 350 pcf, provided the footings are surrounded with properly placed and compacted structural fill and the footing is above the groundwater table. Adjacent floor slabs, pavements, or the upper 12-inch depth of adjacent unpaved areas should not be considered when calculating passive resistance. For footings in contact with structural backfill, a coefficient of friction equal to 0.40 may be used. A safety factor of l. 5 has been applied to the recommended sliding friction and passive pressure. 6.3.4 Settlement We estimate that total post-construction static (consolidation-induced) settlement for conventional and semi-rigid foundation systems should be less than l inch, with differential settlement of up to Y, inch measured along 25 feet of continuous wall footings or between similarly loaded adjacent footings. We expect that settlement for these conditions will tend to occur rapidly after the loads are applied. Immediately prior to placing concrete, all debris and soil slough that accumulated in the footings during forming and steel placement must be removed. Debris or loose soil not removed from the footing excavations will result in increased settlement. 6.3.5 Footing Drains We recommend that footings and basement walls around the buildings be provided with drainage to help manage potential perched groundwater in the upper fill and native soil. Footing drains can consist of free-draining material or prefabricated drainage panel products, with perforated pipes to discharge the collected water. Drainage behind basement walls is described in the "Below-Grade Walls and Retaining Walls" section of this report. The free-draining material should consist of drain rock as specified in the "Fill Materials" section of this report. Alternatively, the free-draining material can consist of clean gravel; however, the gravel should be fully encapsulated within a suitable geotextile filter fabric, such as Mirafi 140N (or similar material). The drainage material should be at least l foot wide and extend from the base level of the footing to within l foot of the ground surface. The free-draining material should be capped with less permeable material, such as the on-site soil. Prefabricated drainage panel products, such as Mirafi Miradrain 6000 (or similar material), consist of a geotextile filter fabric bonded to a molded plastic drainage element. The drainage panel is placed directly against the footing and stem wall and should extend from the base level of the footing to approximately l foot from finished grade. The panel should also be covered with l foot of less permeable material, such as the on-site soil. Footing drains should include a 4-inch-diameter, perforated solid pipe or rigid corrugated polyethylene pipe (ADS N-12 or equal) near the base level of the footing. Where free-draining material is used, the pipe should be installed with approximately 3 inches of drainage material below the pipe. With drainage panels, the geotextile filter fabric should extend from the panel to wrap around the pipe. The pipes should be laid with minimum slopes ofY, percent and discharge into a sump or a water collection system to convey the water away from the building. RDESIGN2 8 KCHA-29-03:021814 DRAFT The pipe installations should include cleanout risers located at the upper end of each pipe run. We recommend that the cleanouts be covered and placed in flush-mounted utility boxes. We recommend that roof downspouts not discharge into the footing drain perforated pipes. 6.4 CONCRETE SLAB ON GRADE 6.4.1 General Conventional slabs may be supported on grade, provided the subgrade soil is prepared as recommended in "Fill Materials" section of this report. We recommend that the slab be founded on structural fill. For slabs designed as a beam on an elastic foundation, a modulus of subgrade reaction of 1 SO pci may be used for subgrade soil prepared as recommended. We recommend that exterior slabs, such as those for walkways, be structurally independent from the structure foundations. This will allow minor movement of the slabs to occur as a result of vehicular loading, tree root growth, seasonal soil shifting, and other factors, while reducing the potential for slab cracking around the perimeter. Interior slabs may be tied to the structure's foundation system. 6.4.2 Underslab Drainage Water seepage and accumulation beneath the basement floor slabs could result in a wet floor condition and/or uplift pressures on the floor slabs. To help prevent this, we recommend installing an underslab drainage collection and discharge system below the slabs. The underslab drainage system should consist of at least 12 inches of 1.5-inch-minus clean crushed gravel with negligible sand or silt (WSS 9-03.1 (4)C, Grading, No. 57). The gravel layer should be placed between deepened foundation elements or below the slab/mat foundations, but should not be placed below the deepened foundation elements. A network of minimum 4-inch-diameter perforated collector pipes should be placed at the base ofthe gravel and should be spaced 20 feet on center. The drainage collector pipe should be either machine slotted or perforated. The underslab drainage system pipes should be routed to discharge into a sump to pump the collected water to the site drainage facilities. We recommend using either heavy-wall solid pipe (SDR-35 PVC) or rigid corrugated polyethylene pipe (ADS N-12, or.equal) for the collector pipes. We recommend against using flexible tubing for collector pipes. A geotextile filter fabric should be placed between the 12-inch-thick gravel layer and the native soil subgrade to maintain separation and reduce piping of the fine-grained soil up into the gravel. The geotextile should be non-woven and conform to the specifications for Class A, underground drainage material provided in WSS 9-33.2(1) -Geotextile Properties, Table 2 Geotextile for Underground Drainage. The geotextile should be installed in conformance with the specifications provided in WSS 2-1 2 -Construction Geosynthetic. The amount of groundwater flow entering the underslab drainage system in each basement area is not expected to be significant. We estimate that the flow from a passive drainage system under each basement slab area will typically be in the range of 1 to 2 gpm, depending on the depth of the final structure configuration. If the basement wall backdrains are routed to the RDESIGNt 9 KCHA-29-03:021814 DRAFT same sumps, the flow combined amounts should be increased to approximately 2 to 4 gpm. However, we recommend that the sumps be sized to accommodate larger pumps if larger flows are experienced. To help prevent basement slab and wall wetness, we recommend that the slabs and walls be waterproofed. The waterproofing should be designed by a waterproofing expert. 6.5 BELOW-GRADE WALLS AND RETAINING WALLS 6.5.1 General The following recommendations should be used for the design of below-grade walls that are intended to act as retaining walls and for other retaining structures that are used to achieve grade changes. 6.5.2 Design Parameters Lateral earth pressures for design of below-grade walls and retaining structures should be evaluated using an equivalent fluid density of 35 pcf, provided that the walls will not be restrained against rotation when backfill is placed. If the walls will be restrained from rotation (i.e., basement walls internally braced by the floor slabs). we recommend using an equivalent fluid density of 55 pcf. Walls are assumed to be restrained if top movement during backfilling is less than H/1,000, where His the wall height. These lateral soil pressures assume that the ground surface behind the wall is horizontal. For unrestrained walls with backfill sloping up at 2H:1V, the design lateral earth pressure should be increased to 55 pcf, while restrained walls with a 2H: l V sloping backfill should be designed using an equivalent fluid density of 75 pcf. These lateral soil pressures do not include the effects of surcharges such as floor loads, traffic loads, or other surface loading. Below-grade walls for the buildings should also include seismic earth pressures. Seismic earth pressures should be determined using a rectangular distribution of 7H psf, where H is the wall height. If vehicles can approach the tops of exterior walls to within one-half the height of the wall, a traffic surcharge should be added to the wall pressure. For car parking areas, the traffic surcharge can be approximated by the equivalent weight of an additional 1 foot of soil backfill (12 5 psf) behind the wall. For truck parking areas and access driveway areas, the traffic surcharge can be approximated by the equivalent weight of an additional 2 feet (250 psf) of soil backfill behind the wall. The fire-fighting apparatus may impose higher surcharge loads than conventional trucks. We should review these loads to evaluate the wall surcharges during final design of the walls. Other surcharge loads, such as from foundations, construction equipment, or construction staging areas, should be considered on a case-by-case basis. These recommendations are based on the assumption that adequate backdrainage will be provided behind below-grade walls and retaining structures as discussed below. The values for soil bearing, frictional resistance, and passive resistance presented above for foundation design are applicable to retaining wall design. Walls located in level ground areas should be founded at a depth of 18 inches below the adjacent grade. An exception to this is for walls sited in close proximity to descending ground. If the ground descends at a slope of 2H: l V below a wall, a •DESIGN/ 10 KCHA-29-03:021814 DRAFT minimum embedment depth of 4 feet will be required. The allowable passive resistance of the soil on the toes ofthese walls is also reduced for conditions where the ground descends below the wall. For a 2H: 1 V descending slope, no passive resistance can be allowed for the upper-most 2 feet of embedment and a reduced allowable passive resistance of 1 SO psf can be used on the lower 2 feet of embedment. 6.5.3 Backdrainage To reduce the potential for hydrostatic water pressure buildup behind the retaining walls, we recommend that the walls be provided with backdrainage. Backdrainage can be achieved by using free-draining material with perforated pipes to discharge the collected water. Positive drainage should be provided behind below-grade walls and retaining walls by placing a minimum 2-foot-wide zone of free-draining backfill directly behind the wall. The free-draining backfill should meet the criteria for WSS 9-03.12(2) -Gravel Backfill for Walls. The free-draining backfill zone should extend from the base of the wall to within 2 feet of the finished ground surface. The top 2 feet of fill should consist of relatively impermeable soil to prevent infiltration of surface water into the wall drainage zone. A 4-inch-diameter perforated drainpipe should be installed within the free-draining material at the base of each wall. We recommend against using flexible tubing for the wall drainpipe. The footing drain recommended above can be incorporated into the bottom of the drainage zone and be used for this purpose. The pipes should be laid with minimum slopes of 0.5 percent and discharge into a sump or the stormwater collection system to convey the water off site. The pipe installations should include a cleanout riser with cover located at the upper end of each pipe run. The cleanouts could be placed in flush-mounted access boxes. We recommend against discharging roof downspouts into the perforated pipe providing wall backdrainage. Collected downspout water should be routed to appropriate discharge points in separate pipe systems. For exterior walls where seepage at the face of a wall is not objectionable, the walls can be provided with weep holes to discharge water from the free-draining wall backfill material. The weep holes should be 3 inches in diameter and spaced approximately every 8 feet center-to- center along the base of the walls. The weep holes should be backed with galvanized heavy wire mesh to help prevent loss of the backfill material. 6.5.4 Construction Considerations Exterior retaining walls used to achieve grade transitions or for landscaping can be constructed using traditional structural systems such as reinforced concrete, concrete masonry unit blocks, or rockeries. Alternatively, these walls can consist of reinforced soil and block-facing structures typically referred to as MSE walls. In recent years, the latter structural system has proven to be an economically reasonable alternative to more traditional retaining wall systems. Because there are many proprietary MSE structure types available, it is typical for the wall provider to complete the design analysis for the wall that will be installed. The parameters given above for earth pressures and sliding resistance can also be used for design of MSE walls. These DDESIGN, 11 KCHA-29-03:021814 DRAFT walls typically have reinforcement embedment lengths of approximately 80 percent of the height of the wall. Minimum embedment depth for MSE walls is 2 feet. We can provide additional design considerations for rockeries, if requested. Care should be taken by the contractor during backfilling of retaining walls to avoid overstressing the walls. Backfill placed within approximately 5 feet of the walls should be compacted with hand-operated or small self-propelled equipment. Heavy compactors or other heavy construction equipment should not be used within approximately 5 feet of the walls. 6.6 STORMWA TER INFILTRATION EVALUATION We anticipate that the bottom of the infiltration pond will be approximately 12 feet BGS. Soil conditions at the base are expected to be sandy silt interbedded with silty sand. Infiltration characteristics of the soil within the project area were evaluated through grain-size distribution tests and in situ testing using the falling head test procedure. The locations of the infiltration tests were selected to correspond with the proposed location of the infiltration pond. All of the tests were conducted in general accordance with the EPA falling head percolation test procedure. The tests were conducted at a depth of approximately 12 feet BGS near the anticipated base of the pond. The infiltration rate determined using falling head test methodology is a short-term infiltration rate. A correction factor is necessary to account for the small scale of the test and other factors in order to estimate the long-term design infiltration rate from the test. Additional corrections to the measured infiltration rate are necessary to account for testing uncertainties, depth to the water table or nearest impervious layer, geometry of the infiltration receptor, and long-term reduction in permeability due to biological activity and accumulation offines. The recommended correction factors to be applied to the "short-term" rate measured in the tests are summarized as follows: • Correction factor F accounts for uncertainties in testing methods. A correction factor of rerflng 0.3 is required by the King County 2009 SWDM for the EPA falling head percolation test. • Correction factor F accounts for the influence of the facility geometry and depth to the -water table or impervious strata on the actual infiltration rate. A shallow water table or impervious layer will reduce the infiltration rate and will not be reflected in a small-scale test like the EPA falling head test. The correction factor is determined by the width of the proposed infiltration facility and the depth from the bottom of the proposed facility to the highest water table level or the nearest impervious layer, whichever is less. We recommend a correction factor F of 0.55. ,..,,.,, • Correction factor F accounts for reduction in infiltration rates over the long term due to ptuggmg the plugging of soil. The correction factor varies between 0.7 for loams and sandy loams to 1.0 for coarse sand or cobbles. The site is underlain by fine-grained material that would be classified as loams or sandy loams, and a correction factor of 0. 7 is recommended. 12 KCHA-29·03:021814 DRAFT The "long-term design infiltration rate" is determined by multiplying the measured rate by the recommended correction factors, which are equivalent to a combined correction factor of 0.12. Table 3 summarizes the infiltration test results along with the correction factor. Table 3. Soil Infiltration Rate Analysis' Infiltration Measured Long-Term Design Point Infiltration Rate Infiltration Rate' (inches per hour) (inches per hour) B-5 4.6 0.55 B-6 5.2 0.62 B-7 2.2 0.26 1. For selected soil samples and test locations 2. Based on the recommended combined correction factor of 0.18 in accordance with King County 2009 SWDM Stormwater infiltration will vary across the site due to the variability ofthe fine-grained alluvium underlying the surficial fill material. We recommend an overall long-term design infiltration rate of 0.4 inch per hour for design of the infiltration pond. 6.6.1 Soil Suitability for Treatment The soil below the planned base of the infiltration pond meets the King County 2009 SWDM for water quality treatment outside of groundwater protection areas. Infiltration will be controlled by the fine-grained layers composed of sandy silt and silt. A CEC of at least 5 meq per 100 grams and a minimum organic content of 0.5 percent are required for water quality treatment (King County SWDM, 2009). Test results indicate that the CEC ranges between 7.4 and 8.6 meq per 100 grams for the samples collected within 2 or 3 feet of the base of the pond, approximately 1 5 feet BGS, which meets the minimum criteria for treatment. Organic matter content of the soil ranges between 0.6 and 0.9 percent in tested samples, which is greater than 0. 5 percent minimum requirement per the design manual. 6. 7 PAVEMENT DESIGN 6.7.1 General We understand that both traditional HMA and pervious HMA pavements are planned for this project. Traditional HMA pavement will be used to construct the access driveways and the drive aisles in the parking areas. Pervious HMA will be used in the parking stall areas. In addition, a perimeter emergency access road around the west and south sides of the main building will be surfaced with Grasscrete. Parking areas will be subject to light automobile traffic. Access driveways will be subject to moderate traffic loading from light delivery trucks and moderately heavy garbage trucks. The Grasscrete road will be subject to light loads from maintenance vehicles and moderately heavy fire-fighting apparatus if needed. We understand that the concrete sidewalk area adjacent to the Grasscrete road will also be designed for moderately heavy fire-fighting apparatus loads. RDESIGNi 13 KCHA-29-03:021814 DRAFT 6.7.2 Traditional HMA Pavement The traditional HMA should be HMA Class Y,-inch PG 64-22, with aggregate, gradation, and asphalt requirements in accordance with WSS Section 9-03.8(6) -HMA Proportions of Materials. This HMA should be compacted to 91 percent of the maximum specific gravity of the mix, as determined by ASTM D 2041. Minimum lift thickness for Y,-inch HMA is l .5 inches. Asphalt binder should be performance graded and conform to PG 64-22. The aggregate base material should meet the specifications for aggregate base rock provided in the "Structural Fill" section of this report. The subgrade should be compacted to at least 95 percent of the maximum dry density, as determined by ASTM D l 557. 6. 7.2. 1 Access Roadway We recommend a pavement section consisting of 3 inches of HMA over 6 inches of l Y.-inch- minus crushed rock in accordance with WSS 9-03.9(3) -Crushed Surfacing Base Course. Alternatively, an applicable pavement section using ATB would consist of 4 inches of ATB and 4 inches of base course. 6. 7.2.2 Parking Area Drive Aisles For the drive aisles in areas limited to automobile traffic only, we recommend a pavement section consisting of 2.5 inches of HMA over 4 inches of l Y.-inch-minus crushed rock in accordance with WSS 9-03.9(3) -Crushed Surfacing Base Course. Alternatively, an applicable section using ATB would consist of 3 inches of ATB and 2.5 inches of base course. 6.7.3 Pervious HMA Pervious pavement is constructed of different materials and layer thicknesses than traditional HMA pavement. To promote infiltration through the HMA layer, more open-graded aggregate is used in the HMA mix and a different binder grade may be used. To provide water storage the crushed base material below the HMA is thicker and also more open-graded than the base course recommended by WSS. To help reduce penetration of the HMA into the open-graded water storage material, a thin choker layer is placed between the water storage material and the HMA. Similarly, a geotextile fabric is placed on the native subgrade soil to help prevent penetration of the subgrade soil into the water storage layer. HMA used for pervious asphalt pavement should be designed as a Y,-inch nominal, open-graded HMA. Selection of the preferred aggregate size should be based on the desired surface texture and the required layer thickness limitations. A recommended aggregate gradation for pervious asphalt is provided in Table 4. 14 KCHA-29-03:021814 DRAFT Table 4. Pervious HMA Gradation (Y, inch) Sieve Size JI:. Inch Percent Passing 1-inch %-inch 99 -l 00 l /2-inch 90-98 3/8-inch #4 18 -32 #8 3 -l 5 #200 0-3 Recommended Layer Thickness 3 (inches) Asphalt binders to construct pervious asphalt pavement include PG 64-22 and PG 70-22. The preferred and recommended asphalt binder is PG 70-22ER (polymer modified); however, its availability can be limited because some of the local asphalt suppliers limit their on-hand binder to PG 64-22. PG 70-22ER is available but is typically stocked by asphalt suppliers for a specific project, which requires pre-ordering it so that it is available when needed. Suppliers prefer a project size of approximately 600 tons of asphalt in order to utilize a complete tanker volume of the binder. The availability and use of PG 70-22ER is further restricted to the warm months of the year because of its stiffness, so it is not readily available between October and May. Projects specifying PG 70-22ER should be scheduled accordingly and specifications should address supplier availability. The binder should be between 5.5 and 6 percent of the pavement section by weight. Compaction of the pervious HMA should consist of approximately two to four complete passes by an 8-ton, dual, steel roller compactor working in static mode only. 6. 7.3. I Pervious Pavement Suhgrade Preparation The subgrade for pervious pavements should be relatively flat (less than 3 percent slope) to prevent uneven ponding of water within the storage aggregate. The exposed subgrade should be proofrolled with a fully loaded dump truck or similar heavy, rubber-tire construction equipment to identify soft, loose, or unsuitable areas. If areas of excessive yielding are identified, the material should be excavated and replaced with water storage aggregate. The subgrade should be compacted to a maximum of 92 percent of the maximum dry density, as determined by ASTM D 1557. (i)11DES1GN1 15 KCHA-29-03:0218 l 4 DRAFT Exposed subgrades will be moisture sensitive and will deteriorate under construction traffic loading under wet conditions. If earthwork construction is expected to extend into the wet season, we recommend limiting the size of the work area and stabilizing the exposed surface by placing the water storage aggregate to protect the subgrade. Construction traffic should be kept off of the pervious pavement subgrade. 6. 7.3.2 Subgrade Geotextile A layer of geotextile fabric should be placed as a barrier between the native soil subgrade and the water storage aggregate. The geotextile should be non-woven and conform to the specifications for Class A, underground drainage material provided in WSS 9-33.2(1) -Geotextile Properties, Table 2 Geotextile for Underground Drainage. The geotextile should be installed in conformance with the specifications provided in WSS 2-1 2 -Construction Geosynthetic. 6. 7.3.3 Pervious Pavement Water Storage Aggregate We recommend that the water storage aggregate layer be 1 2 inches thick. Imported granular material used as water storage aggregate beneath pervious pavements should be clean crushed rock or crushed gravel and sand that meets the criteria ofWSS 9-03.9(2) -Permeable Ballast. Recommended gradations for acceptable storage aggregate are provided in Table 5. Table 5. Pervious Pavement Water Storage Aggregate wss Sieve Size Permeable Ballast Percent Passing 2Y, inches 90 -100 2 inches 65 -1 00 1 Y, inches 1 inch 40 -80 % inch Y, inch No. 4 0 -5 No. 100 0-2 Percent Fracture 75 The storage aggregate should be placed in one lift and be compacted to a firm condition. Over compaction and construction traffic should be avoided. 6.7.3.4 Pervious Pavement Choker Aggregate Imported granular material used as choker aggregate beneath pervious pavements should be clean crushed rock that meets the criteria ofWSS 9-03.9(3) -Crushed Surfacing Top Course. 6.7.3.5 Pervious Pavement Considerations We recommend the following considerations for installation of pervious pavement: &DESIGN,' 16 KCHA-29-03:021814 DRAFT • The long-term performance of pervious pavements is reliant upon proper design, installation, and long-term maintenance. Although design life of pervious asphalt pavement installations in parking areas is commonly indicated to be greater than 20 years, we recommend an assumed pavement design life of between 1 5 to 20 years. • Consideration should be given to limiting the use of pervious pavement to the parking strip and sidewalk areas, while still constructing a water storage aggregate layer beneath the entire roadway. Run-off from the entire roadway can be infiltrated through the parking strip area and into the storage aggregate while reducing construction and long-term maintenance costs. Contributory non-pervious areas to pervious areas should not be more than two times the size of the pervious area. • Consideration should also be given to limiting the thickness of single layer pervious asphalt pavement to a maximum thickness of 4 inches. Sections thicker than 4 inches should be constructed using a layer of asphalt-treated pervious base below the pervious asphalt. • Sediment, organic debris, and bio-mass growth will reduce the permeability of pervious pavement. Regular periodic maintenance is required to maintain the hydrologic performance of the pavement. Maintenance should consist of periodic cleaning by regentative air sweeping and/or vacuum sweeping and flushing with high volume water at low pressure. Based on available information, vacuum sweeping should be performed two to four times per year and flushing at least once per year. • Sanding for snow and ice removal should be avoided on pervious pavement. • Public awareness plans should be developed to educate residents on activities that should be avoided on or adjacent to pervious pavement. • During and after construction, stockpiles of landscaping materials (e.g., topsoil, bark dust, etc.) and construction materials (e.g., sand, gravel, etc.) should not be placed on the pervious pavements. Extreme care should be taken to prevent trafficking of muddy construction equipment over pervious pavements. • Landscaping areas that are adjacent to pervious pavements should be sloped or bermed to prevent run-off from washing debris onto the pavement and designed such that leaf debris does not accumulate on the pavement. These recommendations are based on general assumptions regarding anticipated traffic and assume adequate subgrade and drainage conditions. Pavement materials and placement should conform to WSS. 6.7.4 Grasscrete Pavement Grasscrete pavement is proposed for use to surface an access roadway that will be located around the rear of the future multi-family building complex. The pavement will provide emergency access to the rear of the building complex as well as for building and site maintenance equipment. RDESIGNi 17 KCHA-29-03:021814 DRAFT Grasscrete consists of reinforced concrete that is cast within a plastic cellular "former." The formers are available in several configurations and thicknesses to accommodate different vehicle loads. The concrete is underlain by coarse, open-graded gravel for support and load distribution as in traditional pavement sections. Once the concrete is cured, the exposed former surface is melted away and the internal open spaces are filled with topsoil that is subsequently seeded. The Grasscrete pavement is to be designed to support fire-fighting apparatus. Information from the City of Renton Fire Department indicates that the design fire-fighting apparatus weighs 72 kips (20-kip front and 52-kip rear axles) and utilizes outriggers that impose loads of up to 50.7 kips on pads that measure 26 inches by 26 inches. Grasscrete is a proprietary product manufactured by Grass Concrete Limited of the United Kingdom. We were provided product information for Grasscrete that included an installation brochure titled "Grasscrete, Cast lnsitu Paving System" as well as a link to a web site that contained design information for the Grasscrete product (http://www.grasscrete.com/pdfs/GrasscreteBrochure.pdfl. We also reviewed other design information linked to the product site at www.qrasscrete.com. Based on our review of the available Grasscrete produce information, the Grasscrete pavement appears to be capable of supporting the design fire-fighting apparatus loads. The information is given in the metric SI system. The equivalent fire apparatus weight is 33 tonnes (1 metric tonne equals 2,205 pounds). For this vehicle weight, the following Grasscrete pavement section is recommended: • CG2 or CG2sc formers measuring 1 SO millimeters thick (5.9 inches) should be used. The concrete reinforcement should consist of A3g3 welded-wire mesh. To promote infiltration through the Grasscrete surface, it is underlain by open-graded water storage aggregate that is covered by a thin choker layer and underlain by a geotextile fabric placed on the prepared native subgrade. We recommend that the aggregate layer be 12 inches thick and consist of clean crushed rock or crushed gravel and sand that meets the criteria of WSS 9-03.9(2) - Permeable Ballast. The choker layer should be 1 inch thick and meet the criteria of WSS 9-03.9(3) -Crushed Surfacing Top Course. The subgrade geotextile should be non- woven and conform to the specifications for Class A, underground drainage material provided in WSS 9-33.2(1)-Geotextile Properties, Table 2 Geotextile for Underground Drainage. The aggregate layer should be placed in one lift and compacted to a firm condition. Over compaction and construction traffic should be avoided. Expansion joints within the pavement surface, edging details, concrete placement protocol, and other installation products and details should be consistent with the recommendations of the Grasscrete product manufacturer. We recommend that the contractor who installs the Grasscrete pavement have experience with this product and installation protocol. We also recommend that the Grasscrete manufacturer's representative review and approve this application and the selected installation contractor. RDESIGN1 18 KCHA-29-03:021814 DRAFT The Grasscrete product relies on a soil subgrade with a bearing capacity of 45 kN/m' (900 psi). In our opinion, the subgrade bearing capacity will exceed this requirement provided that it is properly prepared. The subgrade should be relatively flat (less than 3 percent slope) to prevent uneven ponding of water within the storage aggregate. The exposed subgrade should be proofrolled with a fully loaded dump truck or similar heavy, rubber-tire construction equipment to identify soft, loose, or unsuitable areas. If areas of excessive yielding are identified, the material should be excavated and replaced with water storage aggregate. The subgrade should be compacted to a maximum of 92 percent of the maximum dry density, as determined by ASTM D 1557. Exposed subgrades 1.Yill be moisture sensitive and will deteriorate under construction traffic loading under wet conditions. If earthwork construction is expected to extend into the wet season, we recommend limiting the size of the work area and stabilizing the exposed surface by placing the water storage aggregate to protect the subgrade. Construction traffic should be kept off of the Grasscrete subgrade. We understand that the 5-foot-wide sidewalk that is immediately adjacent to the Grasscrete access road is also considered to be part of the fire access road and needs to support the loads of the fire equipment. To accomplish this, we recommend upgrading the sidewalk section thicknesses to be essentially equal to the Grasscrete section thicknesses. We recommend the sidewalk section consist of a 6-inch-thick concrete surface, over a 1-inch- thick choker layer of Crushed Surfacing Top Course [WSS 9-03. 9(3)]. over a 12-inch-thick aggregate layer of Permeable Ballast [WSS 9-03.9(2)]. with a geotextile between the ballast and the prepared subgrade. The geotextile should be Class A, underground drainage material provided in WSS 9-33.2(1) -Geotextile Properties, Table 2 Geotextile for Underground Drainage. The same subgrade and material placement recommendations that were presented above for the Grasscrete area should be used for the sidewalk area. Because the sidewalk is immediately adjacent to the Grasscrete, using the same material thicknesses will facilitate construction of both pavement areas. Sidewalks that are outside the 20-foot-wide fire access area can be conventional section thicknesses. 7.0 SEWER IN STEEP SLOPE AREA 7.1 SLOPE TOPOGRAPHY The vertical height of the slope that the sewer will descend is approximately 35 feet along the trend of the pipe alignment. The slope is inclined at 2H: 1 V. However, the sewer will descend the slope on a slight skew; therefore, the slope inclination along the sewer alignment is slightly less than 2H:1V. The slope was constructed as a fill and the face of the slope is relatively uniform. The slope is vegetated with grass, brush, and trees. Surface water or groundwater seepage was not observed along the pipe alignment or elsewhere on the slope at the time of our visit. DDESIGN/' 19 KCHA-29-03:021814 DRAFT 7.2 SUBSURFACE SOILS The soils encountered in the boring nearest to the sewer alignment (B-3) encountered stiff silt fill and loose, silty sand to a depth of 4.5 feet BGS. The loose sand is underlain by dense sand to 40.5 feet, the maximum depth of the boring. No groundwater was noted in this boring. Based on our observations and experience, it is our opinion that the surficial soils are generally stable and retained by the vegetation on the face of the slope. However, surficial soils on a steep slope are susceptible to downslope movement via raveling and soil creep. Raveling is caused by surface water sheet wash and rilling. Soil creep is generally shallow downslope movement of the upper weathered soil layer (colluvium). The movement generally extends a few feet below the ground surface and often occurs without a well-developed failure surface. Soil creep is often evidenced by bowed tree trunks and leaning or downed trees. The rate of soil creep may be increased by erosion undercutting of the slope or by man-made excavations that over-steepen the slope. Soil creep can also be aggravated by water accumulation. 7.3 SEWER PIPELINE RECOMMENDATIONS We recommend that the sewer pipeline down the slope be completed in a trench to protect the pipeline and to place the pipe below the surficial soils on the face of the slope. The surficial soils are subject to downslope creep due to weathering and erosion and are, therefore, not suitable to support the pipeline. Recommendations for the pipeline construction in the slope area are presented in the following sections of this report. 7.3.1 Site Preparation We recommend that disturbance to the slope surface be minimized. Removal of vegetation and surficial root zone soil should be limited to the immediate vicinity of the trench. The soils on the slope are susceptible to disturbance from equipment and foot traffic. We recommend that construction be performed during periods of extended dry weather to reduce the impacts of stormwater ru naff. 7.3.2 Pipe Construction We understand that the sewer will consist of ductile iron pipe with restrained joints. We recommend that the pipeline be anchored to the manhole at the upper end of the pipeline to provide additional restraint. All temporary cut slopes and shoring must comply with the provisions of Title 296 WAC, Part N, "Excavation, Trenching and Shoring." The contractor performing the work must have the primary responsibility for protection of workmen and adjacent improvements, deciding whether or not to use shoring, and for establishing the safe inclination for open-cut slopes. Temporary unsupported cut slopes more than 4 feet high may be inclined at lY,H:lV maximum steepness. Flatter slopes may be necessary if seepage is present on the cut face. Some sloughing and raveling of the cut slopes should be expected. Temporary covering with heavy plastic sheeting should be used to protect these slopes during periods of wet weather. [fflDESIGNt 20 KCHA-29-03:021814 DRAFT Excavations could encounter seepage, especially in the areas where silty materials are present in the slope. We expect that seepage in excavations can be handled by using sump pumps. The pump discharge hoses should be extended to the bottom of the slope so that water is not discharged onto the slope. 7.3.3 Pipe Burial Depth We recommend that a minimum pipe burial depth of 4 feet be used over the crown of the pipe. This minimum burial depth should be measured from the existing slope surface. The purpose of the minimum cover depth is to position the pipe below the zone of potential surficial instability on the slope. 7.3.4 Pipe Bedding We recommend that bedding consist of sand and smooth, rounded gravel such as specified in WSS 9-031 5 -Native Material for Trench Backfill. The bedding material should extend to 1 foot above the pipe. 7.3.5 Anchor Blocks We recommend that the pipe be restrained with anchor blocks spaced every 50 feet along the pipeline through the steep segment of the sewer. The anchors should consist of blocks of concrete that completely surround the sewer pipe and that are keyed into the native material at least 1 2 inches on the sides and bottom of the trench. The concrete should also extend at least 1 2 inches above the pipe. The anchor blocks should be a minimum of 18 inches wide. The sewer pipe should be sleeved through the anchor blocks with an oversized pipe segment to prevent abrasion of the sewer pipe from contact with the concrete. As discussed below, we recommend that the pipe anchors be penetrated with a perforated pipe to facilitate drainage of the bedding material where silty soils are present along the sewer trench. We understand that this sewer pipeline facility will become the property of Soos Creek Water and Sewer District. Typical details for pipe anchor blocks are presented in the Soos Creek Water and Sewer District Standard Plans. We recommend that the Soos Creek Water and Sewer District Standard Plan anchor blocks be modified to conform to the recommendations presented above. 7.3.6 Thrust Blocks Thrust blocks used to resist lateral pipe loads may be designed using an allowable passive lateral resistance corresponding to an equivalent fluid density of 300 pcf, measured from the ground surface. An allowable frictional resistance of 0.3 5 between the concrete and dense native soil may be used in conjunction with passive resistance. Where the pipe alignment results in a downward thrust load on the soil, an allowable bearing value of 2,000 psf may be used for design of thrust blocks supported on dense native soil. 7.3. 7 Trench Drains Because the majority of the native soils in the slope are relatively free-draining, water accumulation within the trench backfill should not be a concern along most of the steep hill area. BDESIGN?'. 21 KCHA-29·03:021814 DRAFT However, water could accumulate within the trench backfill in the areas where silty soils are present. The pipe bedding will tend to convey seepage along the trench in these areas. Where silty soils are present along the sewer trench, we recommend that the pipe anchors be penetrated through with minimum 4-inch-diameter perforated pipe, installed near the bottom of the pipe bedding horizon. The perforated pipes will allow any accumulated seepage in the sewer pipe bedding to pass through the pipe anchors. We recommend not penetrating the pipe anchors with perforated pipe in areas where relatively free-draining material is present along the sewer pipe. We recommend that the perforated pipe be smooth-wall rigid pipe (SDR-3 5) or ADS N-12 corrugated pipe. The pipe should have two rows of perforations, and the perforations should be installed pointing downward. The perforated pipes should extend to the base of the slope and be discharged to the ground surface at an appropriate location. The end of the pipe at the discharge location should be covered with heavy galvanized wire mesh to prevent rodents from entering the pipe. 7.3.8 Backfill Backfill placed above the pipe bedding material should consist of the native soil excavated from the trench or structural fill imported to the site. Structural fill material should be free of debris, organic contaminants, or rock fragments larger than 3 inches. We recommend that imported structural fill material have no more than approximately 5 percent fines. Trench backfill on the slope should be compacted to a minimum of 90 percent of the maximum dry density, in accordance with the ASTM D 1557 test procedure. 7.4 EROSION PROTECTION Temporary erosion protection should be placed and maintained during construction to protect the slope surface. We recommend use of straw, jute matting, or equal as temporary erosion protection. Following completion of the pipeline construction, the slope surface should be restored and protected from erosion, and the vegetation should be re-established. The slope surface should be mounded up slightly over the sewer pipe trench so that surface runoff does not become channeled and flow along the sewer alignment. We recommend that organic soil or surface strippings be spread over the prepared slope surface approximately 3 inches thick to promote re-vegetation. The surface soil should be tamped in place with lightweight, hand-operated compaction equipment or track-walked with a small dozer operating up and down the slope to achieve a moderate degree of compaction and a texture appropriate for seeding. The disturbed slope area should be covered with an erosion mat to protect the surface until the vegetation is established. Erosion mats are available with jute, straw, excelsior, and coconut fibers; any of these can be used. The mat should be placed and stapled as recommended by the manufacturer. 22 KCHA-29-03:021814 DRAFT Application of the re-vegetation seeding may precede or follow placement of the erosion mat, as recommended by the manufacturer. We suggest that the re-vegetation seed mix be selected by an experienced landscape professional. The seed mix must consider the time of year for application, the steepness and direction of the slope, the available light, and soil conditions. No irrigation should be planned. Maintenance and reseeding as necessary must be anticipated until the vegetation is well established. 8.0 SITE DEVELOPMENT 8.1 SITE PREPARA T/ON The proposed building locations and associated hardscape areas are within an open field with a slope grading upward towards the west and south that is landscaped with grass. Site preparation will generally include stripping and subgrade preparation to prepare the site for grading or fill placement in order to establish the required ground surface elevations. These activities will include removal of vegetation and undesirable material, including stripping of topsoil, subgrade preparation, and site grading. Recommendations for these activities are discussed below. 8. I.I Stripping and Grubbing Stripping and grubbing should include the removal of vegetation, organic material, and man- made debris. Based on the explorations, the organic material (roots and wood debris) generally extends to a depth of 6 inches. The actual stripping depth should be evaluated based on observations made during construction. Stripped material should be transported off site for disposal or used as fill in landscaping areas, provided it meets the requirements for common fill. 8.1.2 Subgrade Preparation After demolition and removal of surficial organic matter, site grading should be completed to the required elevations. Based on the results of our explorations, we anticipate that unengineered fill consisting of silty sand and sandy silt will be exposed at subgrade elevations over most of the site. Over-excavation and replacement of the unengineered fill will be required beneath foundation elements as described in the "Foundation Support -Shallow Spread Footings" of this report. Beneath floor slab and hardscaped areas, over-excavation and subgrade preparation should be consistent with that described in the "Concrete Slab on Grade" section of this report. The exposed subgrade outside ofthe building area in hardscape areas should be scarified to a depth of 12 inches, moisture conditioned, and compacted to a dense and unyielding condition. Soil moisture should be maintained within 2 percent of the optimum moisture content to achieve the required compaction. Following compaction of the subgrade, the exposed surface should be proofrolled with a fully loaded dump truck or similar heavy, rubber-tire construction equipment in the floor slab and RDESIGNi 23 KCHA-29-03:021814 DRAFT paved areas to identify soft, loose, or unsuitable areas. If soft or loose zones are identified, these areas should be excavated to the extent indicated by the engineer or technician and replaced with structural fill or stabilization material. It should be recognized that the exposed subgrade will consist of silty sand and sandy silt with a high fines content. The subgrade will be moisture sensitive and will deteriorate under construction traffic loading during wet weather. If earthwork construction is expected to extend into the wet season, we recommend stabilizing the improved areas by either over-excavating the area and constructing a 12-inch-thick gravel pad or stabilizing with cement-amended soil overlain by 4 inches of crushed rock. 8.1.3 Site Grading Fill required to raise site grades in improved areas should consist of structural fill as described in the "Fill Materials" section of this report. The use of on-site excavation spoils as structural fill will be dependent on the material composition and weather conditions. We anticipate that some of the on-site material will be suitable for use but will be limited to use during the dry season, provided deleterious material (such as wood debris, organics, and man-made material) is removed. ·11 will be prudent to provide an 18-inch-thick cap of imported structural fill over areas where on-site soil is used as fill to protect it against deterioration during wet weather. Fill required to backfill over-excavations beneath foundation elements and floor slabs should consist of imported stabilization material placed and compacted as recommended in the "Fill Materials" section of this report. Fill in unimproved areas, with slopes less than 3H: 1 V, may consist of common fill or on-site excavation spoils, provided deleterious material (such as man-made material and large, woody debris) is removed. Common fill placed in landscape of unimproved areas should be placed in lifts with a maximum uncompacted thickness of 8 to 12 inches and compacted to not less than 90 percent of the maximum dry density, as determined by ASTM D 1557. 8.1.4 Temporary and Permanent Slopes We recommend that temporary slopes for construction of underground utilities and basement excavations be inclined no steeper than 1 YaH: 1 V. Steeper utility or basement excavations will need to be supported by shoring. Permanent slopes should be inclined no steeper than 2H: l V. 8.1.5 Subgrade Evaluation Exposed subgrades should be observed by a representative from GeoDesign to evaluate whether the conditions are as anticipated and will provide the required support. Where pavement or hardscaped areas will be constructed, the exposed su bgrade should be evaluated by proofrolling. Beneath foundations and during wet weather, subgrade evaluation should be performed by probing with a hand probe. 8.1.6 Surface Drainage All ground surfaces, pavements, and sidewalks should be sloped away from the structures. Surface water runoff should be controlled by a system of curbs, berms, drainage swales, and/or 24 KCHA-29-03:021814 DRAFT catch basins and conveyed to appropriate discharge points. Roof drains from structures should be tightlined to discharge into the stormwater collection system. Surface water should not be discharged into subdrains or wall backdrains. 8.2 EXCAVATION 8.2.1 Shallow Excavation The soil at the site can be excavated with conventional earthwork equipment. Excavations should stand vertical to a depth of approximately 4 feet, provided groundwater seepage is not observed in the trench walls. Open excavation techniques may be used to excavate utility trenches with depths greater than 4 feet, provided the walls of the excavation are cut at appropriate cut slopes determined by the contractor. Approved temporary shoring is recommended where sloping is not possible. If a conventional shield is used, the contraaor should limit the length of open trench. If shoring is used, we recommend that the type and design of the shoring system be the responsibility of the contraaor, who is in the best position to choose a system that fits the overall plan of operation and the subsurface conditions. All excavations should be made in accordance with applicable OSHA, local, and state regulations. Open excavation techniques may be used for temporary excavations for basements, provided that there is space to slope the walls. We recommend a slope of I Y,H:I V where space is allowed; if space does not permit, approved temporary shoring is recommended. 8.2.2 Excavation Dewatering We do not anticipate significant groundwater will be encountered in excavations. We recommend that the contractor be responsible for selecting the appropriate temporary dewatering systems. 8.3 FILL MATERIALS We anticipate fill material will be required for site grading, backfilling over-excavations, pavement support, installation of utilities, and drainage. The recommended fill materials are discussed below. 8.3.1 On-Site Soil Fill was encountered to depths of approximately 13 feet BGS in the southwest section of the site and to I foot in the northwest section of the site. The fill is characterized by a high fines content, is sensitive to changes in moisture content, and will deteriorate when exposed to wet weather. We recommend against prospective bidders assuming that all of the on-site excavation spoils can be used as structural fill. We anticipate that some of the excavation spoils can be used as structural fill, provided construaion is completed during the dry season, moisture conditioning is performed, and deleterious material (such as wood, organics, and man-made materials) are removed. The use of on-site soil as fill should be subjea to review and approval by GeoDesign. BDESIGNi' 25 KCHA-29·03:021814 DRAFT The on-site material free of man-made materials and/or large, woody debris may be used in non- structural areas, such as planter areas or unimproved areas. Laboratory testing indicates the moisture content of on-site soil ranges between 5 and 7 percent. Based on our experience with similar soil, the optimum moisture content is approximately 8 to 12 percent. Moderate moisture conditioning efforts of the on-site soil will be required in order to achieve proper compaction. 8.3.2 Off-Site Recycled Fill Material Off-site generated recycled material should not be used on site without approval from the geotechnical engineer and acceptance by KCHA. The use of recycled material will be subject to performance criteria, gradation requirements, and hazardous material testing in conformance with WSS 9-03.21 (1) -General Requirements. Recycled material is not recommended for use beneath building foundations or floor slabs. Provided performance, gradation, and hazardous material testing results are acceptable, recycled material consisting of recycled concrete may be suitable for use beneath hardscape areas outside of the building footprint. 8.3.3 Structural Fill Structural fill placed for general site grading in improved areas should consist of clean, free-draining granular soil (sand and gravel) that is free from organic matter or other deleterious and man-made material, with a maximum particle size of approximately 3 inches and a maximum fines content of 5 percent by dry weight. The use of granular free-draining material will increase the workability of the material during the wet season and the likelihood that the material can be placed and adequately compacted. Imported granular material used for structural fill should be naturally occurring pit-or quarry-run rock, crushed rock, or crushed gravel and sand and should meet the specifications provided in WSS 9-03.14(1) -Gravel Borrow, with the exception that the percentage passing the U.S. Standard No. 200 Sieve does not exceed 5 percent by dry weight. Structural fill should be placed in lifts with a maximum uncompacted thickness of 12 inches and compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1 557. 8.3.4 Common Fill Fill placed in areas of the site where structural support is not required (such as planters, landscaped areas, and detention ponds) is defined as "common fill." Common fill may contain a higher concentration of fines and organic matter than structural fill but should be free of man-made material. Imported common fill should meet the specifications provided in WSS 9-03.14(3) -Common Borrow. On-site material used for common fill should have an organic matter content less than 20 percent. Fill placed in non-structural areas should be compacted to a minimum of 90 percent of the maximum dry density, as determined by ASTM D 1 557. 8.3.5 Hardscape and Pavement Base Course Imported granular material used as aggregate base for pavements and beneath hardscape areas should consist of 1 Y,-inch-minus material meeting the specifications provided in WSS 9-03.9(3) - Crushed Surfacing Base Course, with the exception that the aggregate should have less than 5 percent by dry weight passing the U.S. Standard No. 200 Sieve and at least two mechanically 26 KCHA-29-03:021814 fractured faces. The imported granular material should be placed in lifts with a maximum uncompacted thickness of 12 inches and compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1557. 8.3.6 Trench Backfill DRAFT Trench backfill for utility trenches should consist of and be compacted in accordance with the specifications for structural fill in improved areas and for common fill in non-structural areas. Trenches within the right-of-way should be bedded and backfilled with 5/8-inch-minus crushed rock meeting the specifications provided in WSS 9-03.9(3) -Crushed Surfacing Top Course. 8.3.7 Stabilization Material Stabilization material to backfill excavations beneath foundations or soft subgrade areas should consist of permeable ballast and should meet the specifications provided in WSS 9-03.9(2) - Permeable Ballast. Stabilization material used to fill over-excavations should be placed in 12-inch-thick lifts and compacted to a dense, unyielding condition. 8.3.8 Free-Draining Material Free draining material used in footing drains and in wall backdrains should consist of granular material that meets the specifications provided in WSS 9-03. 1 2(2) -Gravel Backfill for Walls. 8.3.9 Underslab Drainage Gravel The underslab drainage gravel should consist of 1 Y.-inch-minus clean crushed gravel with negligible sand or silt (WSS 9-03. l (4)C -Grading, No. 57). The imported granular material should be placed in one lift and compacted to not less than 95 percent of the maximum dry density, as determined by ASTM D 1557. 8.3. l O Water Storage Aggregate Material used for water storage aggregate in pervious HMA pavement and in the Grasscrete pavement should consist of permeable ballast meeting the specifications provided in WSS 9-03.9(2) -Permeable Ballast. 8.4 GEOSYNTHET/CS If any geotextiles are used on this project, the geotextiles should be installed in conformance with the specifications provided in WSS 2-1 2 -Construction Geosynthetic. 8.4. l Stabilization Geotextile If construction extends into the wet season, stabilization fabric should also be placed in paved areas between the exposed subgrade and granular fill or base course. The geotextile should conform to the specifications for woven soil stabilization material provided in WSS 9-33.2(1) - Geotextile Properties, Table 3 Geotextile for Separation or Soil Stabilization. 8.4.2 Separation and Drainage Geotextile We recommend using a non-woven geotextile material below the slab-on-grade gravel base layer and the water storage aggregate in the pervious HMA pavement and the Grasscrete pavement. The geotextile should conform to the specifications for non-woven separation material RDESIGN2 27 KCHA-29-03:021814 DRAFT conforming to the specifications for Class A, underground drainage material provided in WSS 9- 33.2(1) -Geotextile Properties, Table 2 Geotextile for Underground Drainage. 8.5 CONSTRUCTION STORMWATER CONSIDERATIONS The site is located at the top of a ravine, and surrounding areas on the south and east drain towards the site. Grading during construction should be completed to convey surface water away from construction areas. The soil encountered on site is high in silt, which will be difficult to remove from stormwater using passive systems, such as sediment traps and ponds. 8.6 WET WEATHER CONSIDERATIONS This section describes additional recommendations with potential budget and schedule impacts that may affect the owner and site contractor if earthwork occurs during the wet season. These recommendations are based on the site conditions and our experience on previous construction projects completed in the area. • The fill encountered in the explorations is typically silty sand and sandy silt. The fines content of this material is high, and the soil will be susceptible to deterioration during wet weather. Material below the fill is lower in fines content and will be less susceptible to deterioration during wet weather. If construction is completed or extends into the wet season, we recommend stabilizing the areas of the site where construction traffic is anticipated using either a gravel working pad or cement-treated soil overlain with a 4-inch layer of crushed rock. Additional Best Management Practices will be necessary in cement- treated areas and to monitor/manage the pH levels in stormwater discharge. • Site soil will not be suitable for use as structural fill during wet weather and imported fill will be required. Imported fill will need to consist of non-moisture sensitive material composed of sand and gravel or crushed rock material. • Earthwork should be accomplished in small sections to minimize exposure to wet weather. • Excavation or the removal of unsuitable soil should be followed promptly by the placement and compaction of clean structural fill. • The size of construction equipment and access to the area should be limited to prevent soil disturbance. • The ground surface in the construction area should be sloped and sealed with a smooth-drum roller to promote rapid runoff of precipitation, to prevent surface water from flowing into excavations, and to prevent puddles from forming. • The building pads should be surfaced with a 1 2-inch-thick gravel pad consisting of stabilization material as described in the "Fill Materials" section of this report. This layer will help protect the pad from deterioration under construction traffic during wet weather. The 28 KCHA-29-03:021814 DRAFT protected area should also extend outwards from the building pad a sufficient distance to provide stabilized access for construction equipment around the perimeter of the building. • Additional excavation below planned foundation subgrades should be anticipated in order to construct a 2-inch-thick lean mix concrete rat slab or to install a 6-inch-thick layer of crushed surfacing base course to protect the foundation subgrade from deterioration. • Installation of sumps within excavations may be necessary to remove accumulated stormwater. The sumps should be located outside of the footing footprint and installed to a depth sufficient to lower the water to below the excavated subgrade elevation. • Construction of stabilized access roads using non-moisture sensitive material and geotextile fabric to provide separation from underlying soil should be expected. • Increased handling, excavation, and disposal of wet, disturbed surface material should be expected. • Protection of exposed soil subgrades and stockpiles will be required. • Heavy rainfall can occur during winter months and can compromise earthwork schedules in this region. • In general, snowfall is not dramatically high; however, frozen ground should not be proofrolled or compacted and fill should not be placed over frozen ground. 9.0 OBSERVATION OF CONSTRUCTION Recommendations provided in this report assume that GeoDesign will be retained to provide geotechnical consultation and observation services during construction. Satisfactory earthwork and foundation performance depends to a large degree on the quality of construction. Subsurface conditions observed during construction should be compared with those encountered during the subsurface explorations. Recognition of changed conditions often requires experience; therefore, GeoDesign personnel should visit the site with sufficient frequency to detect whether subsurface conditions change significantly from those anticipated and to verify that the work is completed in accordance with the construction drawings and specifications. Observation and laboratory testing of the proposed fill materials should be completed to verify that proposed fill materials are in conformance with our recommendations. Observation of the placement and compaction of the fill should be performed to verify it meets the required compaction and will be capable of providing the structural support for the proposed infrastructure and buildings. A sufficient number of in-place density tests should be performed as the fill is placed to verify the required relative compaction is being achieved. BDESIGNi'. 29 KCHA-29-03:021814 DRAFT 10.0 LIMITATIONS We have prepared this report for use by Vantage Point Apartments LLC, King County Housing Authority, and its consultants in design of this project. The data and report can be used for bidding or estimating purposes, but our report, conclusions, and interpretations should not be construed as warranty of the subsurface conditions and are not applicable to other nearby building sites. Exploration observations indicate soil conditions only at specific locations and only to the depths penetrated. They do not necessarily reflect soil strata or water level variations that may exist between exploration locations. If subsurface conditions differing from those described are noted during the course of excavation and construction, re-evaluation will be necessary. The site development plans and design details were preliminary at the time this report was prepared. If design changes are made, we request that we be retained to review our conclusions and recommendations and to provide a written modification or verification. The scope of our services does not include services related to construction safety precautions and our recommendations are not intended to direct the contractor's methods, techniques, sequences, or procedures, except as specifically described in our report for consideration in design. Within the limitations of scope, schedule, and budget, our services have been executed in accordance with generally accepted practices in this area at the time the report was prepared. No warranty, express or implied, should be understood. • • • We appreciate the opportunity to be of continued service to you. Please call if you have questions concerning this report or if we can provide additional services. Sincerely, GeoDesign, Inc. DRAFT T omas A. o m, .E. Principal Engineer -DESIGNi 30 KCHA-29·03:021814 DRAFT REFERENCES American Society for Testing and Materials, 2011. Annual Book of ASTM Standards, Vol. 4.08, Soil and Rock (1 ): D420-D4914, Philadelphia: ASTM. Booth, Derek B., Kathy A. Troost, and Aaron P. Wisher (2007), Geologic Map of King County, Compiled March 2007, GeoMapNW, scale 1:100,000. International Building Code, 2012. Johnson, S.Y., S.V. Dadisman, J.R. Childs, and W.D. Stanley, 1999, Active Tectonics of the Seattle Fault and Central Puget Sound, Washington: Implications for earthquake hazards,: GSA Bulletin, v. 111, no. 7, p. 1042-1053. King County, 2009. Surface Water Design Manual, January 9, 2009. Nelson, A.R., S.Y. Johnson, S.K. Pezzopane, R.E. Wells, H.M. Kelsey, B.L. Sherrod, R.D. Koehler, R.C. Buckman, W.T. Laprade, J.W. Cox, and C.F. Narwolds, 2000. Postglacial and Late Holocene earthquakes on the Toe Jam Strand of the Seattle Fault, Bainbridge Island, Washington. Poster, GSA Cordilleran Section Meeting, Vancouver, Canada. Sherrod, B.L., T.M. Brocher, C.S. Weaver, R.C. Bucknam, R.J, Blakely, H.M. Kelsey, A.R. Nelson, and R. Haugerud, 2004, Holocene fault scarps near Tacoma, Washington, Geology, 32, p. 9-12. Washington State Department of Transportation, 2012. Standard Specifications for Road, Bridge and Municipal Construction. M 41-1 0. &DESIGNt ll KCHA-29-03:021814 FIGURES VICINITY MAP BASED ON AERIAL PHOTOGRAPH OBTAINED FROM GOOGLE EARTH PRO") 0 DRAFT N @ 2000 4000 g0ES1GN~ KCHA-29-03 VICINITY MAP II;'-' l0 7C0~1erid,anAveoucNortr Su1te210 ] ! Sedltl~WAYfilll FEBRUARY 2014 VANTAGE POINT APARTMENTS c oc. ~1ffd1n~rn-J400 r,.~i008l89901 RENTON, WA fcL_~~~~~~~_J_~~~~~~___[~~~~~~~~~~~~~_J'---~~~__J FIGURE l f ! ' ' ; ' l ~ .. ' H Ii ~1 ' e ,: ]~ .. <l:a' ,'/· ' , (,.'/ '"-,'/ • ,'/ ;i ' ,. DRAFT LEGEND: BORING ~ 1 ' 0: ' ' ,•, __ .-,l. B-10 8-6@ BORING WITH WELL INSTALLED -·--,, ,,k ._ TP·I~ TEST Pr] ~-"-'-"·-~--''.'; 'L; ---~ ,,._,,, '/ '.: SITE BOUNDARY ,,;0, /,;,; )c' $\'. f ~ I ' ·;,;,:~~-,, ''"TP·l Ii ' "I p!* IA I I ' I.LI I I \ TP·"l !1 ' I: ' "·1 '" J' ' ,:, 1 ~ B-10 c;; ;, ~11 f \ it ' '11 I.I.I "r--1. - t , 1~·11~ L "::,,:;3"'---...,.. , I _i , -~ I~ • •'"=""" _ ------...~~i,, , _ _ ce Jll1JJ1'i11 ·,,·1 scca.a-, ~ ~: \~1,~~C_aC~~~~ -~---~=:--" •. ~i}$lz;o;7J.f~~~-; ,,, ( ~ fu .... ~.,c-__ ~----::-:..., ---..--~ ~:~ -..,<'. ' I' '\.'\:;~·-:t:: -'·-' ·,---· -~-: -;;-~~ =,., ', .:>" .c's, , .. ,, --~ _L_~ .. -'!;-,:;~-•" --c, l-'.1/, ' .._..__ __ -_ . -~-------~-~ .>/ ~, ,1"""' '' ""'" 'M.ii1 I "'·~"EL T:·4., ·_ . ~'."~-_,3" --~~"_-~-;:'~·:_:.:-';o~•,?,.,c... -\J. . ' l't, l~i_; ,,, /, __ ------~: -~-~-~~~-= ~>"'·:,_--~~/if} i·. i -./: 11.1( >~~i;.·.·.TP::6Z----TP.~;.,.ef/i:J~~ /-! i ' I, -' II' :eJ,""' B40 :C . TP;:7 .k'iic'~~~~:2::0 ·;,-< :: : ; . I ' 1<7"1 ,/ , .. ~/11 'llffli · ('t. / I ~I' / 0' / VI, / ~/ I' L1.11r /df, •U1• / ~,.. ,· · I' <:t' I / a.O / I , -.11 · . ,~ ~ \~-~,: ii 011 i !:::'' N 0 ':\ >:--.. ,; i--I / / r "-L __ : @ ·01 " "' -s{1ir1sfsi'r1iiT i ------0 100 (SCALE IN FEET) 200 SITE PL.AN BASED ON DRAWING PROVIDED BY TRIAD ASSOCIATES, DECEMBER 21, 2012 ~ ~ w t: ~ "' z l) ~ 0 I N w "' :, C, ;;; ~ > C ~ ~ < a, ~e 23 ~· ~ ~ 0 i ~ r~· . I ''-. ..,, ;._ -~-,- ., ,· ' !\ '{<. ~-· ,; ~_.ls" -<-·, ~· <· . -v. . ' . ?-- 1 70TH PLACE SE . ':~-',• -\·i .1, _ ... _.__. •• JI'•' "·-· :--r.-.--. "~· ''I-,,;, w ~ ~ z ~ " w ~ ;; ~ cc ~ ;:; g b i: ~ i < ~ :!I ~ j, ~ m ~ => " u: , ~ " if ~ " . ~z ~2 2~ -" ~ i ~'(~~. ·l··,U,\ ',a ' J Jii;J 1· .; l';' ' ... f----'--, ez 0 210 500 (SCALE IN APPROXIMATE FEEn AERIAL PHOTOGRAPH OBTAINED FROM AEROMETRICS PHOTOGRAMMETRIC ANO PHOTOGRAPHY SERVICES, SEA.TILE. WA "' z ,2 ~ 0 I ~ ! 'i ' ~ 3 t * s ! I I -- 1 _,, i "V \'\..-/"l . . ' 1 / ;-:'(-"'i~ ?/, 1-\ 1\;M ', ,,..,-· ~/ L JR \',\ \ \\ \ \\ \ \, I' ' ' ,, \ " I' i ' ,, ,, ,,: /1: I I I Ir" I' ' -.ii /,~,~ ~ )!"Tn '-"' >11 1 11 V)\I, ,II tJ i I <S 1111,1:1 I o.. '!fl!I ~ "' :: ' 11'{1~ LEGEND: 1/7/Z: DRAFT SITE AREA MODIFIED BY PREVIOUS LEGAL GRADING THAT CAN BE RE-GRADED (ALTERED) IN ACCORDANCE WITH THE PROVISIONS OF KING COUNTY ZONING CODE (CRITICAL AREAS) SECTION 21A.24.]10.D.2 ~l !:j ~ ;::.. :'' ,q: I ;i: f J;; I 0 " z 5 :! " ~ ~ => Q i;; i: i:; C w "' ~ i w t: ~ :I :1 ,, " ,,, ---··a.v..:5'='·-~ "ILV..:§-..-~~~~~ S-d=-= --1 1 ... , I 1 'I I,· ---i :, Ii ,i'1 ,r r' 1' 'i ,, ,1 :i r,' ' ', Ii 11 ',I '\ \ \ \. '-., \ " " \'\, " ',"' ,, ',"' '·· I ',i"· ~~, ./'7) ""--.,.,, /! /£::-.''::.-:..::::-. _''"' -·--=t---~-----~----=---=-- '; I ',0 1 _ ~ /1 / --,_,' ---'i, ~r--\\. ' ,'I I ii I ~t-_J_ _ -I I /"> // / / / /r /.,,, / / // _.,.-( / / I / / I ~ I ;I I :! / / / // / / ,, / / I :1 I I , ) I I I ,'I 1-~----11--···-T-----1 -------J L ' ccf--=-- 0 ~ cc_ .--~;-~:~~~~:i--~-=---~---___ ,,/~:: . '~-.--:,;."-,', 'ill I I N @ 0 IOO 200 {SCALE IN FEET) SITE PLAN BASED ON DRAWING PROVIDED BY TRIAD ASSOCIATES, DECEMBER 21, 2012 ~ ~ "' z u ~ i " ::i => ,1 ~ • ~ I. < " . < 'z ~ -· ~~ -· u ~ ! I'_ -~\-~ ' \/--'\·'\. \ '-..v ),?/- '-_'• i '//,\]- 'I -1 C ~ ' -r ! ' ' 0 1 ~ ~I : ' ' ~ ~ e '-,-. ,. v/ i 1 · I", , ' , 6 ,.;,v <( 1 - ,\ \ I . \\_ \ \\ \ I ', i, \, ''-\\ ',\ ',1_ \ :'1 ' I, I ]1 c1 i 'I ii :, ii :1 ,, ' ) I ;1 1,, ,, ' ,,i l) 11 1 111 :, :, " ' ' !'1 " " I I I, ii \. \\ \. \\ \, \\ \,, \," \., '" "'., ',:::,.. ''~ "(~ ~' -";/ ,.._ ' ~- I 1: i11: I ft,,, 1: ,, ~ 11 , .· •• ··, 1:1 1...---I -1:: / /-~ ' ~ ' , . ! I \. ' . \ ~ 11:i I . ; vt i'1·". 11, ~ · \ LIJ 1 , 11_ \ ) I...J I I <S 1111'·' ) .,_ l ,, ii \;. I ' ;c f I I , ""' I "' ' O• l ~ /I t:::"-""----,; I ',," , ... /1 I '·-~ ...._-~---=/-~-~-- ,1 I ,,,_ ' i.VuiiW.~ L...J I 1.V£:',f,w.~ ~;:~--~~ LEGEND: ~ 1DRAFT)J ~ --.-. "c--= . -= -::~-'-i =· Q-::r::n:z::nv:; SE 180TH STREET-• I ! y- EXISTING STEEP SLOPE AND EROSION HAZARD AREA NOTE: ENTIRE SITE IS AN EROSION HAZARD AREA I' ' I' ' 0 I N @ ,00 (SCALE IN FEET) 200 ,1 / ./ 1/ I J., /( -e-c_-,_-c:_;::r~:::--~/y 5~----SITE PLAN BASED ON DRAWING PROVIDED BY TRIAD ASSOCIATES, DECEMBER 21, 2012 ~ "' "' Q "' ~ z Q ~ "' w I~ ~ ~ .. w ~ ~ " z ~ l:I 0 . ' § L_ I => ',1 ~ I-- ~ 3 ~ "• l• < -~8 ~3 -· C < > < , . ~ ~ < ~ • '"z1 ~ f ' ' (,j~~i v=;,, '",: UJ I;:" OJ1! Iii'" CIJf : ., ' I I ;i DRAFT I "' ' ' l . j. ~ __ :1· ·1, ,, j\1 I I -· s,/-,l ,. ·~·,, LEGEND: ----TOP OF STEEP SLOPE HAZARD AREA 1 0-FOOT BUFFER TOP OF STEEP SLOPE HAZARD AREA AT WALL · NO BUFFER REQUIRED NEW STEEP SLOPE HAZARD AREA FOLLOWING RE-GRADING NOTE; ENTIRE SITE IS AN EROS.ION HAZARD AREA r .. .. N @ 0 ,00 (SCALE IN FEED 200 j ' i f/ °'' { ! ~-'-''~#"'"-SITE PlAN BASED ON DRAWING PROVIDED BY ,~JII.-f et~-~: ~(K:" · KPFF CONSUL Tl NC f:NCINEERS, JANUARY 9, 20l 4 ~ :, "' " 0 "' " N " :,: z Q ~ w 0 z " w ,. 0 ~ ~ ,. w w ... ~ ! z 0 • ~ ~, z l.J ifi i w "' :, " .: ~ z , a i~ < . -~ 2~ ·" u ~ z ! . ~ i ~ APPENDIX A DRAFT APPENDIX A FIELD EXPLORATIONS GENERAL Subsurface conditions at the site were explored by completing five additional borings (B-S through B-9) to depths ranging between 16.5 and 61.5 feet BGS. The borings were completed on December 19, 201 3 by Geologic Drilling, Inc. of Spokane, Washington, using a trailer rig and hollow-stem auger drilling techniques. A well was installed to a depth of 60.0 feet BGS in boring B-6. The exploration logs from the recent explorations are included in this appendix. The locations of the explorations were determined in the field by using hand-held GPS equipment. This information should be considered accurate to the degree implied by the methods used. A member of our geotechnical staff observed the explorations. We obtained representative samples of the various soil encountered in the explorations for geotechnical laboratory testing. Samples were obtained using an SPT sampler at 2.5-and 5-foot intervals. SOIL CLASS/FICA TION The soil samples were classified in accordance with the "Exploration Key" (Table A-1) and "Soil Classification System" (Table A-2), which are included in this appendix. The exploration logs indicate the depths at which the soil or its characteristics change, although the change could be gradual. A horizontal line between soil types indicates an observed change. If the change was gradual the change is indicated using a dashed line. Classifications and sampling intervals are presented on the exploration logs included in this appendix. LABORATORY TESTING CLASS/FICA TION The soil samples were classified in the laboratory to confirm field classifications. The laboratory classifications are presented on the exploration logs if those classifications differed from the field classifications. GRAIN-SIZE ANALYSIS We completed grain-size testing in order to determine the distribution of soil particle sizes. The testing was completed in general accordance with ASTM D 422, ASTM C 136, ASTM C 117, and ASTM D 1140. The results of the testing are presented in this appendix. MOISTURE CONTENT We tested the moisture content in general accordance with ASTM D 2216. The moisture content is a ratio of the weight of the water to soil in a test sample and is expressed as a percentage. The overall moisture contents range from 20 to 24 percent. The results of the testing are presented in this appendix. A·l KCHA-29-03:021814 SYMBOL SAMPLING DESCRIPTION Location of sample obtained in general accordance with ASTM D l 586 Standard Penetration Test with recovery Location of sample obtained using thin-wall Shelby tube or Geoprobe® sampler in general accordance with ASTM D l S 87 with recovery Location of sample obtained using Dames & Moore sampler and 300-pound hammer or pushed with recovery Location of sample obtained using Dames & Moore and 140-pound hammer or pushed with recovery Location of sample obtained using 3-inch-0.D. California split-spoon sampler and 140-pound hammer Location of grab sample Rock coring interval Water level during drilling Water level taken on date shown Graphic Log of Soil and Rock Types t ::···:· .:~.-1·~ ./ Observed contact between soil or ~.~ ;., If"" rock units (at depth indicated) ....,,., ... •,,;'+· -=-- / Inferred contact between soil or rock units (at approximate depths indicated) Li.,L .L....--.. . ,,, :~·--· GEOTECHNICAL TESTING EXPLANATIONS ATI Atterberg Limits CBR California Bearing Ratio CON Consolidation DD Dry Density DS Direct Shear HYD Hydrometer Gradation MC Moisture Content MD Moisture-Density Relationship oc Organic Content p Pushed Sample ENVIRONMENTAL TESTING EXPLANATIONS CA p PID ppm Sample Submitted for Chemical Analysis Pushed Sample Photoionization Detector Headspace Analysis Parts per Million pp P200 RES SIEV TOR UC vs kPa ND NS ss MS HS Mi1JDESIGN~ 1 0700 Mend,an ~nue Nonh · SU Re 210 SeanleWA98133 EXPLORATION KEY Off 206.818 9900 F"" 206 838.9901 Pocket Penetrometer Percent Passing U.S. Standard No. 200 Sieve Resilient Modulus Sieve Gradation Torvane Unconfined Compressive Strength Vane Shear Kilo pascal Not Detected No Visible Sheen Slight Sheen Moderate Sheen Heavy Sheen TABLE A-I RELATIVE DENSITY-COARSE-GRAINED SOILS Relative Density Standard Penetration Dames & Moore Sampler Dames & Moore Sampler Resistance (140-pound hammer) (300-pound hammer) Very Loose 0-4 0-11 0-4 Loose 4 -10 11 -26 4 -l 0 Medium Dense l O -30 26 -74 10 -30 Dense 30 -50 74 -120 30 -47 Very Dense More than 50 More than l 20 More than 47 CONSISTENCY -FINE-GRAINED SOILS Consistency Standard Penetration Dames & Moore Sampler Dames & Moore Sampler Unconfined Compressive Resistance (140-pound hammer) (300-pound hammer) Strength (tsf) Very Soft Less than 2 Less than 3 Less than 2 Less than 0.25 Soft 2-4 3-6 2 -5 0.25-0.50 Medium Stiff 4-8 6 -12 5-9 0.50 -1.0 Stiff 8 -15 12 -25 9 -19 1.0 -2.0 Very Stiff 15 -30 25 -65 19 -31 2.0 -4.0 Hard More than 30 More than 65 More than 31 More than 4.0 PRIMARY SOIL DIVISIONS GROUP SYMBOL GROUP NAME CLEAN GRAVELS GWor GP GRAVEL GRAVEL (< 5% fines) GRAVEL WITH FINES GW-GM or GP-GM GRAVEL with silt (more than 50% of (;, 5% and,; 12% fines) GW-GC or GP-GC GRAVEL with clay coarse fraction COARSE-GRAINED retained on GM silty GRAVEL No. 4 sieve) GRAVELS WITH FINES SOILS (> 1 2% fines) GC clayey GRAVEL GC-GM silty, clayey GRAVEL (more than 50% CLEAN SANDS retained on (<5% fines) SW or SP SAND No. 200 sieve) SAND SANDS WITH FINES SW-SM or SP-SM SAND with silt (50% or more of (;, 5% and ,; 1 2% fines) SW-SC or SP-SC SAND with clay coarse fraction passing SM silty SAND No_ 4 sieve) SANDS WITH FINES SC clayey SAND (> 12% fines) SC-SM silty, clayey SAND ML SILT FINE-GRAINED CL CLAY SOILS Liquid limit less than 50 CL-ML silty CLAY (50% or more SILT AND CLAY OL ORGANIC SILT or ORGANIC CLAY passing MH SILT No. 200 sieve) Liquid limit 50 or CH CLAY greater OH ORGANIC SILT or ORGANIC CLAY HIGHLY ORGANIC SOILS PT PEAT MOISTURE ADDITIONAL CONSTITUENTS CLASSIFICATION Secondary granular components or other materials Term Field Test such as organics, man-made debris, etc. Silt and Clay In: Sand and Gravel In: very low moisture, Percent Fine-Grained Coarse-Percent Fine-Grained Coarse-dry dry to touch Soils Grained Soils Soils Grained Soils damp, without <5 trace trace <5 trace trace moist visible moisture 5-12 minor with 5 -15 minor minor visible free water, > 12 some silty/clayey 15 -30 with with wet usually saturated > 30 sandy/gravelly Indicate% (jji1l0ES1GN\1 10700 Meridian Avenu~ North ·SUitt l\O SOIL CLASSIFICATION SYSTEM TABLE A-2 Seattle WA 981 B Off 206.838.9900 Fax 206.818 9901 b '-' z ~ 0 8 '-' DRAFT u 0 ~ DEPTH u 'c MATERIAL DESCRIPTION FEET ~ <( ~ u V Medium dense, light brown SAND (SP), trace silt; dry to moist, fine. 5- I 10 dense; interbedded with dense light brown with interbedded orange layered, silty SAND (SM); moist, fine at 10.0 feet 15- :r Stiff, light brown with orange layered --- SILT with sand (ML); moist, sand is fine. 20-I hard at 20.0 feet sandy at 20.5 feet 25-very stiff at 25.0 feet gray at 25.5 feet - 30-: -I ' Exploration completed at a depth of 31.5 feet. 35 - 40 DRILLED BY: Geologic DrilHng, Inc. BORING METHOD: holow-stem auger (see reporttelCI) Ltii11DESIG N~ KCHA-29-03 l 0700 Meridian Avenue North -Suite 21 0 Seattle WA 98133 FEBRUARY 2014 Off 206.9311.9900 Fax 206.838.9901 II INSTALLATION AND l.J UJ • BLOW COUNT t z -' COMMENTS i= 0.. e MOISTURE CONTENT% UJ ~ 0 V, <( OJI RQO% [7Z CORE REC% -' UJ UJ f-V, 0 so 100 C I I ~ 26 Thin layer of gravel at top of ... sample. -: : ~ -- 30 : ... - u -2S ... • -- u -- 23 SIEV •• 17.0 u IS ... ! -r 31 • ... ' • u ' -- 17 .... -- u ' -- 21 ... 31.S Surface elevation was riot measured at the time of exploration. - -- - • 0 so 100 LOGGED BY· TAP COMPLETED: 12119/13 BORING BIT DIAMETER: 6-1nch BORING B-5 VANTAGE POINT APARTMENTS I FIGURE A-1 RENTON, WA DRAFT z '-' QI <.) A BLOW COUNT 0 u.J ~ ~t z _J INSTALLATION AND DEPTH u MATERIAL DESCRIPTION ;:: 0.. e MOISTURE CONTENT % COMMENTS 'r > u.J ::;; FEET u.J 0 V, D RQD% D CORE REC% ~ u.J <( < _J "' u.J >---V, '-' 0 50 100 f--0 Dense, light brown SAND (SP), trace silt; ~~ Flush-mount dry to moist, fine, interbedded with monument with 2 dense light brown, silty SAND (SM); dry feet of concrete to moist, fine. backfill Native backfill 5- . u 40 I 2-inch, Schedule 40 ... PVC well casing 10-----u 45 ... I ~' ----------------u Dense, light brown, silty SAND (SM); dry 12.5 2B ! to moist, fine. ... ' 15-very dense; moist at 15.0 feet u SIEV • 54 ... , ' r Very stiff, light brown SILT with sand 17.0 (ML); moist, sand is fine. u 18 ... Cuttings are wet at 18.0 feet • . • 20-gray at 20.0 feet u 17 .... • I, - r Hard, gray, sandy SILT wltli gravel(ML); 23.0 i moist to wet, sand is fine to medium, 25-gravel is fine to coarse. II 31 • ... .· Cobble at 24.5 feet . I , Bentonite chips " . I .. I . I , ------------------29.S , 30-Dense, gray, silty SAND (SM), minor II -- • I gravel; wet, fine to medium, gravel is 38 I Cuttings are very wet -... I at 30.0 feet. fine to coarse. 1 ·. -Hard, gray-51LT with sand (ML), minor 33.0 b " ~ gravel; moist, sand is fine to medium, ·1 35-gravel is fine. u 54 interbed of hard CLAY (CH); dry at 35.5 ... feet ·. 0 .·· 8 " - • . 40 0 50 100 ' DRILLED BY: Geologic DriMing, Inc. LOGGED BY: TAfl COMPLETED: 12/19/13 BORING METHOD. holow-stem auger (see report text] BORING BIT DIAMETER: 8-inch lwi:t,1DESIG N~ KCHA-29-03 BORING B-6 10700 Meridian Avenue North· Suite 210 VANTAGE POINT APARTMENTS S~attle WA 98133 FEBRUARY 2014 FIGURE A-2 Off 206.BlB.9900 Fa>: 206.836.9901 RENTON, WA CJ DRAFT Ii 0 lJ w • BLOW COUNT ~ z ...I INSTALLATION AND DEPTH u MATERIAL DESCRIPTION ;:: 0.. e MOISTURE CONTENT% COMMENTS FEET :i: V, ::,: CTI RQD% L".,cJ CORE REC% ~ w < .,: ~ f-V, '--40 CJ 0 50 100 I (continued from previous page) u • 42 A ~ I ~ ;; ~ 'I C . 1 LI ·~ -~ . I'. .· Driller " " . " ~s~~4f'f~::1 from ~ '¥-45- 5ense-;-gray:h,own5AN5 (SP), trace sflt;-45.0 [ ~ . 41 45.0 to 48.0 v wet, fine to medium. • feet. lOfeetofwaterin hole at 45.0 feet. ~-~---- . Dense, gray SAND with silt (SP-SM), 48.0 trace silt; moist to wet, fine to medium, I l 0/20 filter pack gravel is fine. . 50-~ -sand 30 - . A - -2-inch, slotted Schedule 40 PVC, -0.010-inch slot width - -I - I -- . ---1 55 -. very dense at 5 5.0 feet [ r - I 60 = A - --- - • . - 60 '. - rn - 45 - "'I Exploration completed at a depth of 61.5 Surface elevation was 61.5 feet. not measured at the I time of exploration. ! . . 65-~ . . 70-_, . . 75-. . . . ~ ~ LOGGED BY. TAP o DRILLED BY: Geologic DriRing, Inc. g)f------------------------------------------------------COMPLETEO: 12119/13 ~ llORING METHOD: hollow-stem auger (see report text) BORING BIT DIAMETER: 8-inch ~f-------------~---------------------------------------- 8 g u z ~ ~ Ltii,jDESIG N~ l 0700 Meridian A'Venue North · Suite 210 Seattle WA 98133 Off 206.838.9900 Fax 206.838.9901 KCHA-29·03 FEBRUARY 20 l 4 BORING B-6 (continued) VANTAGE POINT APARTMENTS RENTON, WA FIGURE A-2 b " 2 " ~ Q Q ~ ' '-' DRAFT 0 ~ DEPTH <,! MATERIAL DESCRIPTION FEET I ~ < "' '-' -Medium dense, brown SAND (SP), trace silt; dry to moist, fine. 5- j 1 ----------------------Very stiff, brown SILT with sand (ML); I I moist, sand is fine. 10- I I I dense; interbedded with dense 1 brown, silty SAND (SM); moist, fine at 12.S feet l ---------------------- 15-Medium dense, gray SAND with silt (SP- SM); moist, fine. . ----------------------Hard, gray, sandy SILT (ML); moist, sand is fine. 20-very stiff at 20.0 feet I ' I 25- --·-· ------- Very-dense, gray, silty SAND with gravel 30-(SM); moist, fine to medium, gravel is fine to coarse. - Exploration completed at a depth of 31.5 feet. 35- 40 DRILLED BY: Geologic Drilling, loc BORING METHOD. holow-stem auger (see report text) (•1:11J0ES1GN~ KCHA-29-03 1 0700 Meridian A11e11ue North -Su rte 21 a Seattle WA 9Bl 33 FEBRUARY 2014 Off 206.83B.9900 Fax 206.838.9901 I' INSTALLATION AND lJ u.J & BLOW COUNT z ---' COMMENTS f'= Cl. e MOISTURE CONTENT% > u.J ::;: u.J 0 V'> <( KRQD% / /J CORE REC% ---' u.J u.J f-V'> 0 50 100 ! u 17 .. 8.0 u ---- 25 ' .. I SIEV u • 40 .. 14.S u 17 .. 17.0 ~ 31 .. • . . . ~ 28 .. . ~ 29 : .. I i 29.0 Driller Comment· grave[ at ~ f----------29.0 feet. 80 .. 31.5 Surface elevation was not measured at the time of exploration. ' I I 0 50 100 LOGGED BY· TAP COMPLETED: 12119/13 BORING BIT DIAMETER· 6-ioch BORING B-7 VANTAGE POINT APARTMENTS I FIGURE A-3 RENTON, WA 5 " z " t:J C 8 " ' L) DRAFT 0 ~ DEPTH u MATERIAL DESCRIPTION FEET ,' ~ <( ~ L) V Stiff, orange-brown, sandy SILT (ML), trace gravel; moist, sand is fine to medium, gravel is fine. 5 -l Dense, gray1irown SAND (SP), trace silt; dry to moist, fine to medium. 10- . IS-very dense at 15.0 feet ~~- Exploration completed at a depth of 16.5 feet. 20- - 25- 30- 35- 40 DRILLED BV: Geologic Drilling, Int. BORING METHOD: hdlow-stem auger (see report text) (ft&DESIGN~ KCHA-29-03 10700 Meridian Avenue North· Suite 210 Seattle WA 98133 FEBRUARY 2014 Off 206.IB&.9900 Fax 206.838.9901 z QI INSTALLATION AND <.J w A BLOW COUNT !;;:t z ...J COMMENTS ~ o._ e MOISTURE CONTENT% >W ::;: wD "' <( lliJ RQD% 7,7;: CORE REC% ...J w w f-"' 0 50 100 u I 0 .. . ] 14 .. 8.0 Driller Comment: sand at 8.0 feel. • • . ~ ' . 38 .. ! ~ ~3 16.5 Surface elevation was not measured at the time of exploration. • -- i 0 50 100 LOGGED BY: TAP COMPLETED 12119/13 BORING BIT DIAMETER: 6-mch BORING B-B VANTAGE POINT APARTMENTS I FIGURE A-4 RENTON, WA DRAFT z " QI INSTALLATION AND g <.J UJ A BLOW COUNT f-f-z ...J COMMENTS DEPTH u MATERIAL DESCRIPTION <( "-i:: "-e MOISTURE CONTENT% FEET 'i' >"' :;, ~ u,0 "' <( =1 RQD% CZJ CORE REC% "' ...J UJ ~ UJ f-"' " 0 50 100 Very dense, gray-brown SAND (SP), trace ! silt; dry to moist, fine to medium. ' I 5- . I I . 10-interbedded with very dense, gray- -------------- brown, silty SAND (SM); dry to moist, fine at 1 0.0 feet 15-dense at l 5.0 feet ~ -Exploration completed at a depth of 16.5 Surface elevation was not measured at the time of 16.5 feet. exploration. 20- 25- - - 30----------------- - 35 - • • • • • 40 0 50 100 DRILLED BY: Geologic Drilling, Inc. LOGGED BY: TAP COMPLETED: 12/19/13 BORING METHOD: hollow-stem auger (see report tel(!) BORING BIT DIAMETER: 6-1nch iii•1DESIGN~ KCHA-29-03 BORING B-9 1 0700 Meridian Avenue North -Suite 210 VANTAGE POINT APARTMENTS I Seattle WA 98133 FEBRUARY 2 0 l 4 FIGURE A-5 Off 206.838.9900 Fax 206.838.9901 RENTON, WA GRAIN SIZE NO P200 KCHA-29-03-BS_9.G_P)_ GEODESIGN.GDT PRINT DATE· 2.L!...lil4:KT U.S. STANDARD SIEVE NUMBERS 3" I 1/2" 3/4" 3/8" 4 ! .L -.L __..__.j,_ 100 --------- 10 .l 20 40 _.I._ _.l._ -,- 60 l 00 200 DRAFT I I 900 80 -<~~,'-ii. _,_ ~ f-----------+----- f- :i: 70 IJ I '" 3: >-60 "' -j--------~------1 "' '" z 50•· ;;: f-z 40 '" u "' '" .. 30 T 20 ----+---------·-+-··- 10 -,- I I 0 1,000 100 l 0 ---GRAVEL BOULDERS COBBLES COARSE FINE KEY • !JI ... EXPLORATION NUMBER B-5 B-6 B-7 ·-·- [l'J1.1j0ESIGN~ 10700 ld•r>dtan """'"u' Nanh -S"~• 210 SealtleWA981ll Otf 206.BJ8.9900 Fa, 206.8l8.9901 SAMPLE DEPTH MOISTURE CONTENT (FEET) (PERCENT) l s.o l 5.0 12.S 24 20 24 KCHA-29-03 FEBRUARY 2014 l 0.1 0.01 0.001 GRAIN SIZE IN MILLIMETERS le ' -- D60 SAND MEDIUM DSO D30 FINE 010 I OS FINES _J _______ ~ SILT CLAY GRAVEL , SAND ; SILT CLAY (PERCENn , <PERCENT) I <PERCENTli_<PERCENTl 0 . 17 83 0 0 14 6 86 94 ---------+-------------j -- GRAIN-SIZE TEST RESULTS VANTAGE POINT APARTMENTS RENTON, WA J FIGURE A-6 b " 2 "' :fl 0 8 " ' SAMPLE INFORMATION EXPLORATION SAMPLE ELEVATION NUMBER DEPTH (FEET) (FEED B-5 I 5.0 . ---- B-6 1 5.0 B-7 12.S - (•j:111DESIGN~ 1 0700 Meridian A~cnuc North Su11e 21 O Seanl~ WA 981 33 OH 206.838.9900 Fax 206.838.9901 MOISTURE DRY CONTENT DENSITY (PERCEND (PCF) 24 20 24 KCHA-29-03 FEBRUARY 2014 DRAFT SIEVE ATTERBERG LIMITS GRAVEL SAND P200 LIQUID PLASTIC PLASTICITY (PERCEND (PERCEND (PERCEND LIMIT LIMIT INDEX (PERCEND (PERCEND (PERCEND ! ' I 0 I 17 I 83 0 I 14 i 86 i 0 ! 6 94 SUMMARY OF LABORATORY DATA VANTAGE POINT APARTMENTS I FIGURE A-7 RENTON, WA APPENDIX B "' u ' ' '-' D ~ DEPTH ',! MATERIAL DESCRIPTION FEET I ~ <( "' '-' f--0 ~ r\~oft, dark brown SILT with organics I (roots); moist (topsoil). . Stiff, brown SILT with concrete debris, cobbles, and boulders (ML), trace sand; moist, low plasticity, sand is fine -FILL. light brown, sandy at 3.75 feet 5- ------- Dense, light brown with orange mottled SAND (SP); dry, fine. without mottles at 7.5 feet 10-very dense at l 0.0 feet - - 15- trace silt at 16.0 feet I Very dense, light brown SAND with silt (SP-SM); dry, fine. 20- with orange mottles at 20.5 feet -Very stiff, gray SILT (ML), trace sand; dry, medium to high dry strength, low ' plasticity, sand is fine. 25- I . Very dense, gray, silty SAND (SM); dry, . I I fine. 30- • . I----- Hard, gray Sil T (ML), trace sand; dry, medium to high dry strength, low 35-plasticity, sand is fine. I 40 DRILLED BY: Holt Services, Inc. BORING METHOD: hdlow-stemauger (see report text) ttii1j0ES1G N~ KCHA-29-01-02 10700 Meridian Avenue North • Suite 210 Seattle WA 98133 MARCH 2013 Off 206.838.9900 Fax 206.838.9901 z QI INSTALLATION AND I.J UJ • BLOW COUNT ~t z _, COMMENTS f'= Cl. e MOISTURE CONTENT% >"' ::;: u,0 "' <( =rrJ RQD% V /J CORE REC% _, UJ UJ f-"' 0 50 100 . r 0.5 l II " Felt cobbles or racks; hard . . drilling at 4.0 feet. I : 12 " Debris encountered at 4.0 7.0 feet. Moving approximatE!ly 3 feet south. u 43 • • : : • I . 25-53-10015" u -. --- 61 " 18.0 I u ! 52 • ' 22.5 ' I ' u I------- 23 " 28.0 . I . • 1 08 Outside of sampler was wet at 30.0 feet. Perched water at approximately 30.0 feet. 33.0 i ~ - 37 .... I • • 0 50 100 LOGGED BY: TAP COMPLETED· 02/25113 BORING BIT DIAMETER: 8-inch BORING B-1 VANTAGE GLEN -MULTI-FAMILY RENTAL PROJECT I FIGURE A-1 RENTON, WA LJ II INSTALLATION AND 0 <.) w A BLOW COUNT ~ t z ...J COMMENTS DEPTH ',i i= o._ e MOISTURE CONTENT% I MATERIAL DESCRIPTION UJ ::;: FEET ~ 0 V, <( J1[ RQD% 77: CORE REC% "' ...J UJ "' f-V, c.__40 LJ a so 100 ITI (continued from previous page) II 37 .. - Exploration completed at a depth of 41.5 Surface elevation was not 41.5 feet. measured at the time of ellploration . 45-• - - - 50 55 -- 60--- - 65 -- I i 70 75 ~- - ' ' • 80 0 SO 100 DRILLED BY: Holt Services, Inc. LOGGED BY: TAP COMPLETED: 02/25/13 BORING METHOD: hollow-stem auger (See report teld) BORING BIT DIAMETER: 8-inch (l'UltJDESIGN~ KCHA-29-01-02 BORING B-1 (continued) l 0700 Meridian Avenue North • Suite 210 VANTAGE GLEN· MULTI-FAMILY RENTAL PROJECT I Seattle WA 98133 MARCH 2013 FIGURE A·l Off 206.838.9900 Fax 206.838.9901 RENTON, WA b " z ~ "' Q 8 " a, " ' ~ ~, N 9 L) 0 ~ DEPTH u FEET 'i: ~ "' ~ .--o L) - i 5- JO- I ' ' ' 15- . 20- 25 - - I -I ' 30- . 35- MATERIAL DESCRIPTION Soft, brown SILT with sand (ML), trace gravel; moist, low dry strength, low plasticity, sand is fine, gravel is fine - FILL. Very stiff, light brown, sandy SILT (ML); dry, low dry strength, low plasticity, sand is fine -FILL. gray, with sand; medium dry strength at 1 0.0 feet Very stiff, gray, SILT (ML), trace sand; moist, sand is fine, medium dry strength, low plasticity. hard at 20.0 feet becomes with sand, trace gravel; high dry strength, sand is fine to medium 1 gravel is fine at 25.0 feet Very dense, brown with orange mottled SAND with silt (SP-SM), minor gravel; dry, fine to medium, gravel is fine. Very dense, brown SAND with gravel (SP); dry, fine to medium, gravel is fine. z QI l"J f-f-z <( "-~ >W wO "' ...J w w f- 7.0 n.o 28.0 33.0 w ...J 0.. ::; <( "' ~i I ~ I ~ ~ I I] .6. BLOW COUNT e MOISTURE CONTENT% =rJ RQD% [72] CORE REC% 0 i 7 " . • • so 100 . . ' i • • i 17 "- 34 . " -----. ----- 27 "- i I . " " • 1.' --------+--------j 28-91-10013", '°" . 28-50/5".; ~ INSTALLATION AND COMMENTS 40~~-'-------------------'---'---'--~,---'·-'-'---'---,',,---'----'------,-!,~----------1 50 I 00 ~r-----"-"_"_'_'°_'v_,_""_'_s_=_,re_,._,,_, ____________ ,_o_c_c_eo_~_r_A_P ___________ c_o_M_P_LE_T_eo_,_,v_,_&_,_' ____ -1 i BORING METHOD. hollow-stem auger(see repor1 text) BORING BIT DIAMETER: B-inch ~r------------~---------~----------------------------1 " g ~ ~ ~ (iji11DESIG N~ l 0700 Meridian Avenue Non:h • Suite 21 O Seattle WA 981 3l Off 206.1138.9900 Fax 206.838.9901 KCHA-29-01-02 MARCH 2013 BORING B-2 VANTAGE GLEN -MULTI-FAMILY RENTAL PROJECT RENTON, WA I FIGURE A-2 '-' It INSTALLATION AND 0 lJ w _. BLOW COUNT ~ z ---' COMMENTS DEPTH u f'= "-e MOISTURE CONTENT% FEET :i: MATERIAL DESCRIPTION w ::. ~ a "' < JII RQD% l7,/J CORE REC% "' ---' w ~ w f-"' '-' 0 50 JOO -4. interbeds of trace silt at 40.0 feet u 24-39-50/3" Exploration completed ati depth of 4 l.3 Surface elevation was not 41.25 feet. measured at the time of eKploration . 45-. • • • 50-• • . . 55-. . 60-i . . 65-. . 70-. 75-r· ----. ' ' • . 80 0 50 JOO DRILLED BY: HcM.SeNices. Inc. LOGGED BY. TAP COMPLETED: 02125/13 BORING METHOD: holow-stem auger {see report text) BORING BIT DIAMETER: S-inch twii110ES1GN~ BORING B-2 KCHA·29·0l-02 (continued) 10700 Meridian Avenue North · Suite 210 VANTAGE GLEN· MULTI-FAMILY RENTAL PROJECT I Seattle WA 9813] MARCH 2013 FIGURE A·2 Off 206.838.9900 Fax 206.838.9901 RENTON, WA ' ~ ~, m N 9 9 DEPTH FEET ~ ~u:J~o ~~ ~ & BLOW COUNT e MOISTURE CONTENT% i '! ;1 RQD% / /i CORE REC% INSTALLATION AND COMMENTS ~ MATERIAL DESCRIPTION ~1-: ; ~o,-....:'-'::,..1--~----~-------------+--l--+--ol---------','''---------'-i'-'-'-----------I Stiff, brown SILT (ML), trace sand; I • moist, low dry strength, low plasticity, sand is fine -FILL. 1 I ji -Loose:lfght brown, silty SAND with 3-8 5 _ ,-\~ra_vel (SM); dry, fine to medium, gravel / ,.s \IS fine. [ I [ 10- . 15- 20- 25- 30- 35- Very derise, brown With orange mottled SAND with gravel (SP), trace silt; dry, fine to medium, gravel is fine to coarse. without mottles at 10.0 feet brown at 1 S .0 feet Very dense, brown, silty SAND with gravel (SM); dry, fine to medium, gravel is fine to coarse. ---- Very dense, brown SAND with gravel (SW); dry, fine to coarse, gravel is fine to coarse. DRILLED BY: Hott Services, Inc. I L 18.0 [ 23.0 [ I] I LOGGED BY: TAP 9 ... . . . . . ' i ' ! I . 28-78-100/5'_. I" 76 .... Gray felt at approximately 4.0 feet. : : 18-1?-100/4'_. • 8-50/5","' 26-50/5'_. • SPT left in boring overnight. Large, smooth obstruction at approximately 21.0 feet. Drilling refusal met at 21.0 feet; hole terminated. Blew hydraulic hose at 21.0 feet. Coane gravel at approximately 22.0 feet 42-5016" Moved boring approlomately • 10 feet northwest of original boring down to 25.0 feel. 47-5015" 34---10015" COMPLETED: 02/26113 ~1-------------------------------------------------------i "' ::i:: BORING METHOD: hollow-stem auger (see report text) BORING BIT DIAMETER: 8-inch s/1-------------~----------~------------------------------i '-' g ':I ~ al (wijz,1DEs1c N~ l 0700 Meridian Avenue North • Suite 21 0 Seattle WA 9Sl 33 Off 206.838.9900 Fa;,,, 206.838.9901 KCHA-29-01-02 MARCH 2013 BORING B-3 VANTAGE GLEN -MULTI-FAMILY RENTAL PROJECT I FIGURE A-3 RENTON, WA " C, ' ' " '3 DEPTH \! MATERIAL DESCRIPTION FEET I ~ < "' " -40 rJcont_i_nued from previous page) '----/ Exploration completed at a depth of 40.S feet. 45- - 50- 55 - 60- - 65 - 70 75 ... . 80 DRILLED BY: Holt Services, Inc. BORING METHOD: holow-stem auger (see report text) tti:i,1DEs1c N~ KCHA-29-01-02 I 0700 Meridian A~11ue North -Suite 21 0 Seattle WA 98133 MARCH 2013 Off 206.838.9900 Fax 206.838.9901 It INSTALLATION AND CJ w .t. BLOW COUNT z -' COMMENTS i= c.. e MOISTURE CONTENT% >"' :. wCl "' <( [IL RQD% IZZi CORE REC% -' w w f-"' 0 so JOO u =o". 40.5 Surface elevation was not mea~ured al the time of exploration. . . - • . . • -- . ' ----- • i 0 so JOO LOGGED BY: TAP COMPLETED: 02/26113 BORING BIT DIAMETER: S.inch BORING B-3 (continued) VANTAGE GLEN -MULTI-FAMILY RENTAL PROJECT 1 FIGURE A-3 RENTON, WA 5 " 2 " ~ 8 " "' " ' ' " g " z ~ ~ CJ 0 ~ DEPTH u MATERIAL DESCRIPTION FEET 'i: ~ "' ~ CJ -o 1 I Stiff, brown SILT with sand and gravel (ML); moist, low dry strength, low plasticity, sand is fine, gravel is fine - FILL I Very dense, light brown SAND (SP); dry, 5-fine to medium. gray; moist, interbeds of very dense, gray, silty SAND (SM); moist, fine at 7 .0 feet 10- Hard,-gray SILT with sand (ML); d,y;1-,igh dry strength, low plasticity, sand is fine. Very dense, gray SAND (SP), minor 15-gravel, trace silt; dry, fine to medium 1 gravel is fine. Very dense, gray, silty SAND (SM); dry, -fine, interbeds of very dense, gray 20-SAND (SP); dry, fine. ' ' 11 -' Hard, gray SILT with sand (ML); dry, high dry strength, low plasticity, sand is fine. 2S- i I 30-I minor gravel at 31.0 feet ' 3S-I interbeds of very dense, gray SAND (SP), -minor gravel; dry, fine to medium, ' gravel is fine at 35.0 feet I Very dense, gray SAND (SP); dry, fine. 40 DRILLED BY: Holt Services, Inc. BORING METHOD· hollow-stem auger (see report text) lwl:r110ES1G N~ KCHA-29-01 ·02 l 0700 Meridian Avenue North -Suite 21 0 Seattle WA 98133 MARCH 2013 Off 206.838.9900 fax 206.838.9901 z QI INSTALLATION AND <.J w A BLOW COUNT f--f--z ....J COMMENTS <( 0.. f'C 0.. e MOISTURE CONTENT% >w :a; wD V, <( :_:r;: RQD% Z2J CORE REC% ....J w w f-"' 0 50 JOO I u 9 I A 4.0 Hard grinding at I ~----.. --approximately 4.0 feet. 111 •• u S7 A . I • • 15B ,, 11.0 13.5 [ 84 A 18.0 u 62 A 23.0 ! . • . u . 58 A . u • • 66 A f ~--~~ ------ 82 A 38.0 Hard grinding at 38.0 feet. . 0 50 100 LOGGED BY: TAP COMPLETED: 02126113 BORING BIT DIAMETER: 8-inch BORING B-4 VANTAGE GLEN· MULTI-FAMILY RENTAL PROJECT I FIGURE A-4 RENTON, WA 5 " z " i1i 0 iil " ' ' Cl 0 ~ DEPTH u MATERIAL DESCRIPTION FEET i: ~ <( ~ '--40 Cl (continued from previous page) ' Exploration completed at a depth of 41.0 feet. 45- so- - 55 - 60 65- - 70- . 75- 80 DRILLED BY: Holt Services. Inc. BORING METHOD. halow-stem auger (see report text) (tlDDESIGN~ KCHA-29-01-02 10700 Meridian Avenue North • Suite 21 O Seattle WA 98133 MARCH 2013 Off 206.838.9900 Fax 206.838.9901 II INSTALLATION AND lJ w ..t. BLOW COUNT I;: z ...J COMMENTS w >= Q. e MOISTURE CONTENT% ~D ::;; "' < I:IJ RQD% Lc'.J CORE REC% ...J w w f-V, 0 50 IOO • I 31-10016",~ 41.0 Surface e!ev,mon was not measured at the time of I exploration. ' • • • I I - • • • ---- - I --- • --- • I ! i ' i • 0 50 100 LOGGED BY: TAP COMPLETED· 02/26/13 BORING BIT DIAMETER. 8-inch BORING 8-4 (continued) VANTAGE GLEN -MULTI-FAMILY RENTAL PROJECT I FIGURE A-4 RENTON, WA z u QI lJ 0 w ~ ~b: z ..., eMOISTURE DEPTH u MATERIAL DESCRIPTION f'= a_ CONTENT COMMENTS FEET ,' >"' :;; . ~ wCl "' <( (%) < ..., w "' w f-"' I. u I TP-1 0 50 100 0.0 p TOPSOIL (6 inches). ,, Soft, brown SILT with sand (ML),~ 0.5 )<J +-- \ low dry strength, low plasticity, sand 1s 1.0 \fine -FILL. Ll 6-inch orange streak at 2.0 feet. 2.5-Medium dense, light brown SAND (SP), trace gravel; moist, fine to medium, pp pp= 2.35 tsf gravel is fine. Nuclear density: 118.1 pcf, dense at 3.5 feet moisture l 8.6 percent at 4.0 feet. 5.0- Very dense, light brown, silty SAND 6.0 (SM); dry, fine. Ll 7.5-I 10.0-'!' ' .. ---pp PP= >4.5 tsf Exploration completed at a depth of 10.5 Ll No groundwater seepage observed 1 0.5 feet. to the depth explored. No caving observed to the depth 12.5-explored. -Surface elevation was not -measured at the time of exploration. 0 50 100 TP-2 0 so 100 0.0 . c TOPSOIL (6 inches) . ''"'' Soft, brown SILT with sand and gravel 0.5 (ML); moist, low dry strength, low pp pp= 1.0 tsf plasticity, sand is fine, gravel is fine to 2.5-coarse -FILL. Dense, light brown with orange mottled 3.3 Ll Nuclear density: 112.6 pcf, pp moisture 13.5 percent at 3.S feet. SAND (SP), trace silt; dry, sand is fine. pp= 2.65 ts/ 5.0- horizontal orange streaks at 5.5 feet very dense, without horizontal streaks at 6.0 feet N 7.5- 10.0-No groundwater seepage observed to the depth explored. ' No caving observed to the depth e)(plored. ' Exploration completed at a depth of 12.0 Ll 12.5 - -12.0 feet. Surface elevation was not measured at the time of exploration. - - 0 so JOO EXCAVATED BY: Continental Dirt Construction LOGGED BY· TAP COMPLETEb· 02127/13 EXCAVATION METHOD trac:khoe(seereporttext) (l'li•1DESIGN~ KCHA·29·01 ·02 TEST PIT 10700 Mer1d1an Avenue North -Suite 210 VANTAGE GLEN -MULTI-FAMILY RENTAL PROJECT I Seattle WA 98 l 33 MARCH 2013 FIGURE A·S Off 206.838.9900 Fa~ 206.838.9901 RENTON, WA " z ! I 0 QI <.:J ~ !;;:t w, DEPTH u z ...J eMOISTURE MATERIAL DESCRIPTION F= "-COMMENTS FEET :i: >"' ::;: CONTENT ~ u,0 "' "' ...J uJ <( (%) ~ uJ f-"' " TP-3 o.o 0 50 100 .,,_ TOPSOIL (6 inches). Stiff, brown SILT with sand and 0.5 . cobbles (ML), minor gravel; moist, low SJ Nuclear density: 123.7 pcf, -dry strength, low plasticity, sand is pp moisture 18.2 percent at 1.75 feet. 2.5-fine, gravel is fine to coarse -FILL. pp= 2.5 tsf . . 5.0 Loose, gray, silty SAND with gravel and 5.0 debris (SM); wet, fine to medium, 13; Moderate to severe caving gravel is fine to coarse, debris includes observed at 6.0 feet. logs, copper pipe, and concrete brick - 7.5-FILL. ' I I I 10.0- tl Very dense, gray, silty SAND (SM); dry, 11.0 pp SJ PP= >4.5 tsf \fi_n_e. . I 11.5 No groundwater seepage observed 12.5-Exploration completed at a depth of to the depth explored. . l l .5 feet . Surface elevation was not measured at the time of exploration . • TP-4 0 50 100 0.0 0 50 IOO I:.( "TOPSOIL (6 inches). ___ _, . , Soft to medium stiff, brown SILT (ML), O.S I minor sand and gravel; moist, low dry Nuclear density: 123.2 pcf, I strength, low plasticity, sand is fine to pp SJ moisture 16.5 percent at 2.0 feet. 2.5-medium -FILL. i pp= l.6 tsf 5.0-Moderate caving observed at 5.0 feet. Loose to medium dense, gray, silty 6.0 SAND to SAND with silt (SM/SP-SM), 13; 7.5-minor gravel and debris (concrete, wood, and pipe); wet -FILL. I 10.0- ,: ; ' : I No groundwater seepage observed :x:J to the depth explored. ' Exploration completed at a depth of 11.5 Surface elevation was not ' 12.5-11.5 feet. measured at the time of exploration. 0 so 100 EXCAVATED BY: Cootinenlal Dit CDnslruction LOGGED BY. TAP COMPLETED: 02127/13 EXCAVATION METHOD: trackhoe (see report text) (jj1110ES1G N~ KCHA-29-01 ·02 TEST PIT 10700 Meridran Avenue Nonh · Suite 210 VANTAGE GLEN· MULTI-FAMILY RENTAL PROJECT I SeatdeWA.98133 MARCH 2013 FIGURE A-6 Off 2'06.838.9900 Fax 206.838.9901 RENTON, WA b " z " ta a a ::, 5 ' ' u 0 ~ DEPTH u MATERIAL DESCRIPTION FEET J: ~ < ~ u TP-5 0.0 ,...,., TOPSOIL (6 inches). Medium stiff, brown SILT with gravel (ML), minor sand; moist, low dry ' I strength, low plasticity, sand is fine to 2.5-medium -FILL. s.o- I Dense, light brown with orange mottled SAND with silt (SP-SM); moist, fine to medium. Very dense, brown SAND wi"ih gravel 7.5-(SW); moist, fine to coarse, -......:...-... approximately 40% fine to coarse -"\gravel. r Exploration completed at a depth of -8.25 feet. 10.0- 12.5- - TP-6 0.0 TOPSOIL (6 inches). 1 Medium stiff, brown SILT with sand and cobbles (ML), minor gravel;. moist, 2.5 - low dry strength, low plasticity, sand is fine to medium, gravel is fine -FILL. 5.0 Hard, gray, sandy SILT (ML); dry, high - dry strength, medium plasticity, sand is . fine. . 7.S Exploration completed at a depth of 7.5 feet. 10.0- 12.S- - EX CA VA TED BY· Conbnental Dirt Consll\Jction EXCAVATION METHOD: tracklloe (see report text) lwlit1DESIG N~ KCHA-29-01-02 10700 Meridian Avenue North -Suite 210 Seattle WA 981]3 MARCH 2013 Off 206.838.9900 Fa:i,; 206.838.9901 2 QI <.) UJ 1-t 2 ....J eMOISTURE ~UJ f'= 0.. COMMENTS ::,: CONTENT UJO V, <( (%) ....J UJ UJ I-V, 0 50 I 00 ' ' o.s pp SJ PP= 2.1 tsf Nuclear density: 122.9 pcf, 4.5 pp SJ moisture 20.7 percent at 4.5 feet. pp= 3.5 tsf 6.5 No groundwater seepage observed [xJ to the depth explored. No caving observed to the depth explored. 8.3 Surface elevation was not measured at the time of exploration. i . i 0 50 I 00 0 50 I 00- . 0.5 pp pp= 0.3 tsf pp [xJ pp= 1.0 tsf Nuclear density: 118.5 pcf, moisture 19.8 percent at 4.0 feet. 5.0 pp [Z PP= >4.5 tsf Difficult to continue excavating . 7.5 No groundwater seepage observed to the depth explored. No caving observed to the depth explored. Surface elevation was not measured at the time of exploration. ' ' : .. ' 0 so 100 LOGGED BY: TAP COMPLETED: 02/27113 TEST PIT VANTAGE GLEN -MULTI-FAMILY RENTAL PROJECT I FIGURE A-7 RENTON, WA C, 0 II l) w ~ f-DEPTH u z _, eMOISTURE MATERIAL DESCRIPTION "-fC' "-COMMENTS FEET i' w :;;: CONTENT ~ Cl "' .,: _, w < (%) ~ w f-"' C, ' TP·7 o.o 0 50 l 00 ·~"· ~ TOPSOIL (6 inches). pp PP= 4.5 ts! Stiff to very stiff, brown SILT with 0.5 sand, gravel, and cobbles (ML), minor 2.5- debris; moist, low dry strength, low plasticity, sand is fine to medium, gravel is fine to coarse -FILL. pp [SJ Minor caving observed at 3.0 feet. pp= 2.0 tsf 5.0--- Very stiff to hard, gray, sandy SILT (ML); 5.0 dry, low dry strength, low plasticity, sand is fine . . ~ 7.5-pp PP= >4.5 tsf Laminated pieces of light brown Very dense, light brown SAND with silt, 8.0 [g with orange streaked, fine, silty ~\gravel, and cobbles (SP-SM), moist, fine / sand from 8.0 to 9.0 feet. to medium, gravel is fine to coarse. 9.0 No groundwater seepage observed 10.0-Exploration completed at a depth of 9.0 to the depth explored. . feet . Surface elevation was not . measured at the time of . ' exploration. 12.5- . • • •• TP·S 0 50 100 o.o 0 50 100 ,"·" TOPSOIL (6 inches). . . Stif(brown SILT with sand, gravel, and 0.5 cobbles (ML); moist, low dry strength, pp PP= 2.2 tsf 2.5- low plasticity, sand is fine to medium, ! gravel is fine to coarse -FILL. ' rR PP = 1.4 tsf pp i 5.0-'i '' pp pp= 3.5 tsf -1/eri dense, gray, silty SAND (SM); dry, 7.5-7.0 . i\~ine . :xJ orange layer at 8.0 feet I 8.0 No groundwater seepage observed Hard, light brown with o·range mottled [SJ to the depth explored. SILT (MH), trace clay and sand; dry, No caving observed to the depth 10.0 r e)(plored. 'i medium to high dry strength, medium 10.0 1 1 to high plasticity, sand is fine, I Surface elevation was not I ' 1 1 1amina~e~_ lay_ers. I measured at the time of I Exploration completed at a depth of e)(ploration. ' 12.5-l 0.0 feet. 0 50 JOO EXCAVATED BY: Continental Dirt COnstruc:tioll LOGGED BY: TAP COMPLETED: 02/27/13 EXCAVATION METHOD. trackhoe (s~ report text) (iji,1DESIGN~ KCHA-29-01-02 TEST PIT 10700 Meridian Avenue North -Suite 21 O VANTAGE GLEN -MULTI-FAMILY RENTAL PROJECT I Seattle WA 98133 MARCH 2013 FIGURE A·8 Off 206.638.9900 Fa)< 206.838.9901 RENTON, WA b u z u ~ 0 0 ::, ~ '? '? ~ C) It 0 L, UJ ~ z ...J eMOISTURE DEPTH ,d MATERIAL DESCRIPTION e= "-CONTENT COMMENTS FEET :c >"' ::; ~ u,D V, < (%) « ...J UJ ~ UJ f-V, C) TP-9 o so 100 o.o ~_rr __ rr_~~T~O~P~S~O~IL~(6~in-c'h_e_s7)_---------~-,--,_-5--r-P-P-,-~~------,-P-P_=_3 ___ 5_ts_f _________ -l 'stiff to very stiff, brown, gravelly SILT 2.5 - 5.0- 7.5- with sand (ML); moist, low dry strength, low plasticity, gravel is fine to coarse, sand is fine to medium - FILL. Hard, dark brown, sandy SILT with gravel (ML); dry, high dry strength, low plasticity, sand is fine to medium, gravel is fine to coarse, intermittent layers of clean gray fine to medium sand. Hard, gray, sandy SILT with cobbles and 1 o.o -. boulders (ML), minor gravel; dry, high . 1 1 1 dry strength, low plasticity, sand is fine, L "gravel is fine. r Exploration completed at a depth of 11 .0 feet. 12.5 - pp :xi 4.0 9.0 11.0 PP= 4.0 ts/ Nuclear density: 123.6 pcf, moisture 18.5 percent at 3.5 feet. No groundwater seepage observed to the depth explored. No caving observed to the depth explored. Surface elevation was not measured at the time of exploration. TP-l o o so , oo 0 so 100 o.o~_rrp"'"····""r--.~T=o=p5"'0"'1""L""'(""6~in-c""'h-e-s'"").---------.--..---r-r---c----,r--------------1 ! Medium stiff, brown SILT with sand o.s and cobbles (ML), minor gravel; moist, 2.5- 5.0- " 7.5- 10.0- 12.5- " " low dry strength, low plasticity, sand is fine to medium, gravel is fine to coarse • FILL. light gray layer at 4.0 feet with large pieces of wood and debris at 5.0 feet boulder (3-foot diameter) at 7.0 feet wood and concrete pieces at l 0.0 feet Exploration terminated due to severe caving at a depth of 11.0 feet. 11.0 Moderate to severe caving observed from 3.0 to 7.0 feet. Slow groundwater seepage observed at l 0.0 feet. Surface elevation was not measured at the time of exploration. < • • ~ 1---~-~-----------------~-~-~"""*---,,s---·.!cc---------------t ~ 0 so 100 w ~ EXCAVATED BY: continental D1r1 Construction LOGGED BY: TAP COMPLETED: 02/27/13 ~1---------------------------------------------------1 EXCAVATION METHOD· trackhoe {see r6P')rt text) Nl------------~---------~----------------------------f (l'lit1DESIG N~ 10700 Meridian Avenue North -Suite 210 Seattle WA 98 l 33 Off 206.838.9900 Fax 206.838.9901 KCHA·29·01 ·02 MARCH 2013 TEST PIT VANTAGE GLEN· MULTI-FAMILY RENTAL PROJECT RENTON, WA I FIGURE A-9 z 1 " QI 0 lJ w. I ~ f--t z ...J: eMOISTURE DEPTH \,! MATERIAL DESCRIPTION <Cw e= "-' CONTENT COMMENTS FEET I i;j 0 V, ~I I ~ (%) "' ..., w "' w f-- " TP-11 0 so 100 0.0 '""---'. TOPSOIL (6 inches). "., . : I Medium dense, li\iht b"iown, silty SAND 0.5 I (SM); moist, fine, laminated pieces. 2.5 -': i [><'. i; dense to very dense; layers of orange at '. 2.5 feet No groundwater seepage observed Ii to the depth explored. No caving observed to the depth explored. 5.0 Exploration completed at a depth of 5.0 5.0 5<J feet. Surface elevation was not measured at the time of exploration. 7.5- 10.0- . . 12.5- I . I 0 50 100 ' EX CAVA TEO BY: Continental Dirt Construc~on LOGGED BY· TAP COMPLETED: 02/27113 EXCAVATION METHOD. tr.ickhoe (see report telct) ttii,jDESIG N~ KCHA-29·01-02 TEST PIT 10700 Meridian Avenue North • Suite 11 O VANTAGE GLEN -MULTI-FAMILY RENTAL PROJECT I Seatt~ WA 981:B MARCH 2013 FIGURE A-10 Off 206.838.9900 Fax 206.838.9901 RENTON, WA APPENDIX C 'i 9 Analytical Re,o,uces, lnco,po,ated Analytical Chemists and Consultants 13 January 2014 Tyler Pierce GeoDesign, Inc. 10700 Meridian Avenue North, Su~e 210 Seattle, WA 98133 RE: Project: Samples Received 12/30/13 ARI Job No.: XS97 Dear Tyler: /<P&-IP:,-0( kc1-+4 -'-Cf-o t Please find enclosed the original Chain-of-Custody record (COC) and the final results for the samples from the project referenced above. Analytical Resources, Inc. (ARI) accepted four soil samples on December 30, 2013. The samples were analyzed for CEC and organic matter as requested. These analyses proceeded without incident of note. An electronic copy of this report and all supporting raw data will remain on file with ARI. Should you have any questions regarding these results, please feel free to contact me at your convenience. Respectfully, ANALYTICAL RESOURCES, INC. 7ro{,2)~ Mark-·D. Harris - Project Manager 206/695-6210 markh@arilabs.com www.arilabs.com eFile: XS97 Enclosures MDH/mdh _ Page 1 of 4611 South 134th Place, Suite 100 • Tukwila WA 98168 • 206-695-6200 • 206-695-6201 fax >t iJ ,,., .;,-,-, ''"• -- ·/ . .,;>.:.,vdt!:H.c,•.\-/-•. ,;,c,, " '-,·t-: SC,/ "·'°", Chain of Custody Record & Laboratory Analysis Request ARI Assigned Numberc -/ 'J'.1 l Turn-around Requested: Page: of s Analytical Resources, Incorporated Analytical Chemists and Consultants ARI Client Company: G ·l _-· I, Phone G-,G,,) ~(i~ -:;.i~/ Date: I lee 4611 South 134th Place, Suite 1 00 -, ""'(., e..~, 7 i'\ t\C L,_.v f f -, /.. U Present? (\ \ Tukwila, WA 98168 Client Contact: Tyk.-!)t-~·\CL No.of Cooler 206-695-6200 206-695-6201 ifax) (]) \+ 0 www.arilabs.com Coolers: Temps: -,:::::::;, Client Project Name: Analysis Requested Notes/Comments Client Project#: Samplers: J :;t '-.l Sample ID i) I.I__\ Date Time Matrix ''"' No. Containers ,_. "'-) 0 kc,b r . l\s'-CI f, z_ "' -'-{ IZ/'Juiz •. ,t 3 ·.I\ So, I i x.. < l(CH!j 2'(-Go, E --, -..)"·'.)-.-·) ;2/,...;f~ ., -' . .:...:,15 "3, : { ( :; ~, / \ "· X k..lHA 2i~~'s t3~z ',-3, ;2/-:;.D/U.,~ S. I 1 $sis\ I )( )<. /lLl~A Z(r~c·i [5-( S<~ 2.11.~it-.3. },. I I s "./ I !( y ~ ' Comments/Special Instructions Rttlinquished ~fil .. #,,..,-~·· Received by-~ _/ Re!ir,qui$hed by: Received by: (Signature) i:.. ·Lf.-, . , . ---:i. (Signature) , __. ---(Signature) (Signature) Printed Name: 'v P,im,d:'f\; Printed Name· Printed Name. ,.1 lc~ L(T:bh.( ~--{ /. ,· · 'c:,\c,r,o--(c,r;n C~ny: -~ 6<cccles:,~ L-..e-. company: µ:\Zi ' ! ,_, Company: company: Date& Time: -- Dat\~e: :\ Date & Time: Dale & Time: 12/1,)z.01, s: i 2 \~ ~( (SG--i~/ ~ ! t-2, Limits of Liability: ARI will perform all requested services in accordance with appropriate methodology following ARI Standard Operating Procedures and the ARI Quality Assurance Program. This program meets standards for the industry. The total liability of ARI, its officers, agents, employees, or successors, arising out of or in connection with the requested services, shall not exceed the Invoiced amount for said services. The acceptance by the client of a proposal for services by ARI release ARI from any liability in excess thereof, not withstanding any provision to the contrary in a.ny contract, purchase order or co- signed agreement between ARI and the Client. Sample Retention Policy: All samples submitted to ARI will be appropriately discarded no sooner than 90 days after receipt or 60 days after submission of hardcopy data, whichever is longer, unless alternate retention schedules have been established by work-order or contract • Analyticai! Resources:1 lnc:orporated Analytical Chemists and Consultants (~ . ARI Clienl: ---''-,CJ"(...1'C_-·.,;(~-t,._' ·"'(;-"(:;.,_' -'-'i c";_\!,.,Vc_1c_ __ COC No(s) ________ ) ___ ('.'NA Project Name·---------.,.,.-..,-------- Delivered by. Fed-Ex UPS Courier f~ De·;~-~red Other: __ _ ---·-·--"' Assigned ARI Job No. --~"'-·_r=,__c-,-1-1'----Tracking No: /NA Preliminary E){amination Phase: Were intact, proper1y signed and dated custody seals attached to the outside of to cooler? Were custody papers included with the cooter? .. Were custody papers properly filled out (ink:, signed, etc.) . Temperature qf Cooler(s) re) (recommended 2.0-6.0 °"C for chemistry) YES ~; @ --· (§ NO NO Time: 151? J].b __ If cooler temperature is out of compliance fill out form 00070F Temp Gun ID#:C)~-:._}c~- Cooler Accepted by ----Lt~_,_v-=-· _________ Date: _,r~J'-Jfr'-'· ""'"'"/'--1 "'-5'--Time: i c; k::;i_ Complete custody forms and attach all shipping documents Log-In Phase: Was a temperature blank included in the cooler? .. . YES {~q / Bubble Wrap Wet Ice Gel Packs G!~s Foam Block Paper Other· _____ _ What kind of packing ma!erial was used? . Was sufficient ice used {if apprnpriate)? Were all bottles sealed in individual plastic bags? . Did alt bottles arrive in good condition (unbroken)? Were all bottle labels complete and legible? . Did the number of contamers listed on COC match with the number of containers received? . Did all bottle labels and tags agree with custody papers? . Were all bottles used correct for the requested analyses? . Do any of the analyses (bottles) require preservation? (attach preservation sheet, excluding VOCs) .. Were all VOC vials free of air bubbles? . Was sufficient amount of sample sent in each bottle?. Date VOC Trip Blank was made at ARI NA YES ((~!: ® I'{_§$' 'fES. (ES YES YES ~Jl ;f.Jo, ( < • '1<Jci -~ NO NO NO NO NO NO NO Was Sample Split by ARI : ~ YES Date/Time.:_------Equipment: _______ _ Split by: __ _ SamplesLogqe0<dUbb)yL: _____ -_!r3_·..)_ _____ _LDi,a"'te,;_·~---/ ;,l;_,,;_~2 .. ci..;-;;i-}.>a:,.iIJiiroruee:·~~'6~,a:·z;;··~/====~----- '"" Notify Project Manager of discrepancies or concerns "" Samole ID on Bottle Samote ID on COC Samnle ID on Bottle Additional Notes, Discrepancies, & Resolutions: Bv: Smalt Air B1Jl;,l;II~ ~ 0016F 312110 -·7.n>m • . • Date: --· l:~4-rum ®.•.• LA""" /\~ Bu-. Small~ "sm" (<2mm) >4mm Peabubbles 7 "pb" ( 2 to< 4 mm) • • • Large, "lg"( 41 to<6mm) ··---. ·-·· Headspaee ~ "hs" ( > 6 mm) Cooler Receipt Form Sample ID on ~oc ~·~ Revision 014 Sample ID 1. KPG 18-01 B-2 S-4 2. KCHA 29-03 8-3 S-3 3. KCHA 29-03 B-2 S-3 4. KCHA 29-03 8-1 S-3 Sample ID Cross Reference Report ARI Job No: XS97 Client: GeoDesign Inc Project Event: N/A Project Name: N/A ARI ARI ANALYTICAL a RESOURCES '8/ INCORPORATED Lal> IO LIMS ID Matrix Sample Date/Time VTSR XS97A 13-28262 Soil 12/30/13 15:11 12/30/13 XS97B 13-28263 Soil 12/30/13 15:11 12/30/13 XS97C 13-28;) 64 sou 12/30/13 15: 11 12/30/13 XS97D 13-28265 Soil 12/30/13 15: 11 12/30/13 Printed 12/31/13 Page 1 of 1 15:12 15: 12 15: l? 15: 1) 9 Analytkal Re,oum,s, lnco,po,aled Analytical Chemists and Consultants !Client: GeoDesign, Inc. Case Narrative ARI Job No.: XS97 1. Four samples were submitted for analysis on December 31, 2013. 2. The samples were submitted for loss on ignition determination according to ASTM 02974, Method A and C. 3. The data is reported in percent, and is provided in summary tables. 4. There were no noted anomalies in the samples or methods on this project. Released by: §~1ik'~- Lea Technician Reviewed by: ,J(LDt,. i{I (/ft,~2_ Geotechnical Laoratory Manager Date, \i.i\\UlYt,J 8, 2-ll\Y ---------------·----------------~-- 4611 South 134th Place, Suite 100 • Tukwila WA 98168 • 206-695-6200{":::296,i69i~A,J.fe,)f, • Analytical Resources, Incorporated Analytical Chemists and Consultants Data Reporting Qualifiers Effective 2/14/2011 Inorganic Data U Indicates that the target analyte was not detected at the reported concentration • B N NA H L Duplicate RPO is not within established control limits Reported value is less than the CRDL but 2 the Reporting Limit Matrix Spike recovery not within established control limits Not Applicable, analyte not spiked The natural concentration of the spiked element is so much greater than the concentration spiked that an accurate determination of spike recovery is not possible Analyte concentration is :ss times the Reporting Limit and the replicate control limit defaults to ±1 RL instead of the normal 20% RPD Organic Data u • B J D E Q Indicates that the target analyte was not detected at the reported concentration Flagged value is not within established control limits Analyte detected in an associated Method Blank at a concentration greater than one-half of ARl's Reporting Limit or 5% of the regulatory limit or 5% of the analyte concentration in the sample. Estimated concentration when the value is less than ARl's established reporting limits The spiked compound was not detected due to sample extract dilution Estimated concentration calculated for an analyte response above the valid instrument calibration range. A dilution is required to obtain an accurate quantification of the analyte. Indicates a detected analyte with an initial or continuing calibration that does not meet established acceptance criteria {<20%RSD, <20%Drift or minimum RRF). Page 1 of 3 {'. ' ,~ :,j s NA NR NS M M2 Analytical Resources, Incorporated Analytical Chemists and Consultants Indicates an analyte response that has saturated the detector. The calculated concentration is not valid; a dilution is required to obtain valid quantification of the analyte The flagged analyte was not analyzed for Spiked compound recovery is not reported due to chromatographic interference The flagged analyte was not spiked into the sample Estimated value for an analyte detected and confirmed by an analyst but with low spectral match parameters. This flag is used only for GC-MS analyses The sample contains PCB congeners that do not match any standard Aroclor pattern. The PCBs are identified and quantified as the Aroclor whose pattern most closely matches that of the sample. The reported value is an estimate. N The analysis indicates the presence of an analyte for which there is presumptive evidence to make a "tentative identification" Y The analyte is not detected at or above the reported concentration. The reporting limit is raised due to chromatographic interference. The Y flag is equivalent to the U flag with a raised reporting limit. EMPC Estimated Maximum Possible Concentration (EMPC) defined in EPA Statement of Work DLM02.2 as a value "calculated for 2,3, 7,8-substituted isomers for which the quantitation and /or confirmation ion(s) has signal to noise in excess of 2.5, but does not meet identification criteria" (Dloxin/Furan analysis only) C The analyte was positively identified on only one of two chromatographic columns. Chromatographic interference prevented a positive identification on the second column P The analyte was detected on both chromatographic columns but the quantified values differ by 2:40% RPD with no obvious chromatographic interference X Analyte signal includes interference from polychlorinated diphenyl ethers. (Dioxin/Furan analysis only) Z Analyte signal includes interference from the sample matrix or perfluorokerosene ions. (Dioxin/Furan analysis only) Page 2 of3 Data Release Authorized: SAMPLE RESULTS-CONVENTIONALS XS97-GeoDesign Inc Project: NA Event: NA Matrix: Soil ~ 1 Reported: 01/13/14 ~- \ Date Sampled: 12/30/13 Date Received: 12/30/13 Analyta Total Solids Client ID: KPG 18-01 B-2 S-4 ARI ID: 13-28262 XS97A Data Method Units 01/03/14 SM2S40G Percent 010314U Cation Exchange Capacity 01/08/14 9080 rneq/100 g 010814#1 RL Analytical reporting limit u Undetected at reported detection limit Soil Sample Report-XS97 RL 0.01 0.01 ANALYTICAL IA RESOURCES. INCORPORATED Sample 79. 97 0.88 SAMPLE RESULTS-CONVENTIONALS XS97-GeoDesign Inc Project: NA Event: NA Matrix; Soil r Data Release Authorized \, Reporte,d; 01/13/14 \ ) Date Sampled; 12/30/13 Date Received; 12/30/13 Analyta Total Solids Client ID: KCHA 29-03 B-3 S-3 ARI ID; 13-28263 XS97B Data Method Units 01/03/14 SM2540G Percent 010314#1 Cation Exchange Capacity 01/08/14 9080 meq/100 g 010814#1 RL Analytical reporting limit u Undetf:::!cted at reported detection limit Soil Sample Report-XS97 RL 0.01 0.01 ANALYTICAL a RESOURCES '9 INCORPORATED Sample 79. 96 8. 63 SAMJ?LE RESULTS-CONVEN'XIONALS XS97-GeoDesign Inc Project: NA Event: NA Matrix: Soil ~, / Data Release Authorized: -. 1 Reported: 01/13/14 , Date Sampled: 12/30/13 Date Received: 12/30/13 Client ID: KCIIA 29-03 B-2 S-3 ARI ID: 13-28264 XS97C Analyte Total Solids Cation Exchange Capacity Date 01/03/14 010314#1 01/08/14 010814#1 RL Analytical reporting limit Method SM2540G 9080 U Undetected at reported detection limit Soil Sample Report-XS97 Units Percent meq/100 g RL 0. 01 0.01 ANALYTICAL ta RESOURCES'U' INCORPORATED Sample Bl. 41 7.35 Data Release Authorized: SAMPLE RESULTS-CONVENTIONALS XS97-GeoDesign Inc , I Project: NA Event: NA Matrix: Soil ~: Reported: 01/13/14 ·, J Date Sampled: 12/30/13 Date Received: 12/30/13 Client ID: KCHA 29-03 B-1 S-3 ARI ID: 13-28265 XS97D Analyte Total Solids Cation Exchange Capacity Date 01/03/14 010314#1 01/08/14 010814#1 RL Analytical reporting limit Method SM2540G 9080 U Undetected at reported detection limit Soil Sample Report-XS97 Units Percent meq/100 g RL 0.01 0.01 ANALYTICAL ta RESOURCES\9' INCORPORATED Sample 80.92 7. 68 METHOD BLANK RESULTS-CONVENTIONALS XS97-GeoDesign Inc ' Matrix: Soil r!)J,/ Data Release Authorize~} yr Reported: 01/13/14 \} Analyte Total Solids Cation Exchange Capacity Date 01 /03/14 01/08/14 Project: Event: Date Sampled: Date Received: Units Percent < meq/100 g Soil Method Blank Report-XS97 NA NA NA NA Blank 0.01 u 0.02 ANALYTICAL/& RESOURCES '9 INCORPORATED QC ID ICB PREP GEOTECHNICAL ANALYSIS DATA SHEET Organic Matter by Method ASTM D2974 Data Release Author.i.zed:r Reported: 01/08/14 · QC Report No: XS97-GeoDesign Inc Project: Date Received: 12/30/13 Page 1 of 1 Client/ ARI ID KPG 18-01 B-2 S-4 XS97A 13-28262 KCHA 29-03 B-3 S-3 XS97B 13-28263 KCHA 29-03 B-2 S-3 XS97C 13-28264 KCHA 29-03 B-1 S-3 XS97D 13-28265 Date Sampled 12/30/13 12/30/13 12/30/13 12/30/13 Analysis Matrix Date Soil 01/06/14 10:45 Soil 01/06/14 10:45 Soil 01/06/14 10:45 Soil 01/06/14 10: 4 5 Organic/Ash Content Burn Temperature 440 C Per ASTM D2974 Report for XS97 Result 45.38 47.31 42.17 41. 87 ANALYTICAL IA RESOURCES\gl INCORPORATED GEOTECHNICAL ANALYSIS DATA SHEET Ash Content by Method ASTM D2974 Data Relea.se Authorizect:Vjt Reported: 01/08/14 V Date Received: 12/30/13 Page 1 of 1 QC Report No: XS97-GeoDesign Inc Project: Cl.ient/ ARI ID KPG 18-01 B-2 S-4 XS97A 13-28262 KCHA 29-03 8-3 S-3 XS97B 13-28263 KCHA 29-03 B-2 S-3 XS97C 13-28264 KCHA 29-03 B-1 S-3 XS97D 13-28265 Date Sampl.ed 12/30/13 12/30/13 12/30/13 12/30/13 Analysis Matrix Date Soil 01/06/14 10: 45 Soil 01/06/14 10: 4 5 Soil 01/06/14 10: 45 Soil 01/06/14 10: 45 Organic/Ash Content Burn Temperature 440 C Per ASTM D2974 Report for XS97 Result 54.62 52.69 57.83 58.13 ANALYTICAL liiJlt. RESOURCES. INCORPORATED GEOTECHNICAL ANALYSIS DATA SHEET Total Solids by Method ASTM D2974 Data Release Authorized:tyV Reported: 01/08/14 f Date Received: 12/30/13 Page 1 of 1 CHent/ ARI ID KPG 18-01 B-2 S-4 XS97A 13-28262 KCHA 29-03 B-3 S-3 XS97B 13-28263 KCHA 29-03 B-2 S-3 XS97C 13-28264 KCHA 29-03 B-1 S-3 XS97D 13-28265 Date Sampled 12/30/13 12/30/13 12/30/13 12/30/13 QC Report No: XS97-GeoDesign Inc Project: Analysis Matrix Date Result Soil 01/06/14 10:45 79.64 Soil 01/06/14 10:45 79.42 Soil 01/06/14 10:45 81. 30 Soil 01/06/14 10:45 80.93 Report for XS97 ANALYTICAL ta RESOURCES\9' INCORPORATED 9 Analytkal Re,ou«es, Inc. orporated 9a Analytical Chemists and Consultants 17 January 2014 Tyler Pierce GeoDesign, Inc. 10700 Meridian Avenue North, Suite 210 Seattle, WA 98133 RE: Project: Samples Received 12/30/13 ARI Job No.: XS97 Dear Tyler: Please find enclosed corrected reports for the samples from the project referenced above. As discussed, the original results for Organic Matter and Ash Content were incorrect due to an error in recording tare weights. The samples have been dried and re-weighed. An electronic copy of these reports will remain on file with ARI. Should you have any further questions, please feel free to contact me at your convenience. Respectfully, ANALYTICAL RESOURCES, INC. , o,,,,,,,/,7 . C>{ ; /Y':2:.-- D. Harris Project Manager 206/695-6210 markh@arilabs.com www.arilabs.com eFile: XS97 Enclosures MDH/mdh Page 1 of ,:,,/ 4611 South 134th Place, Suite 100 • Tukwila WA 98168 • 206-695-6200 • 206-695-6201 fax GEOTECHNICAL ANALYSIS DATA SHEET Organic Matter by Method ASTM D2974 Data Release Authorized:r Reported: 01/17/14 , QC Report No: XS97-GeoDesign Inc Project: Date Received: 12/30/13 Page 1 of 1 Client/ ARI ID KPG 18-01 B-2 S-4 XS97A 13-28262 KCHA 29-03 8-3 S-3 XS97B 13-28263 KCHA 29-03 8-2 S-3 XS97C 13-28264 KCHA 29-03 B-1 S-3 XS97D 13-28265 Date Sampled Matrix 12/30/13 Soil 12/30/13 Soil 12/30/13 Soil 12/30/13 Soil Reported in % Analysis Date 01/06/14 10: 4 5 01/06/14 10: 45 01/06/14 10:45 01/06/14 10:45 Organic/Ash Content Burn Temperature 440 C Per ASTM D2974 Report for XS97 Result 0.40 0.90 0.62 0. 67 ANALYTICAL a RESOURCES\91 INCORPORATED GEOTECHNICAL ANALYSIS DATA SHEET Ash Content by Method ASTM D2974 Data Release Authorized.:[~ Reported: 01/17 /14 / Date Received: 12/30/13 Page 1 of 1 QC Report No: XS97-GeoDesign Inc Project: · Client/ ARI ID KPG 18-01 B-2 S-4 XS97A 13-28262 KCHA 29-03 B-3 S-3 XS97B 13-28263 KCHA 29-03 B-2 S-3 XS97C 13-28264 KCHA 29-03 B-1 S-3 XS97D 13-28265 Date Sampled Matrix 12/30/13 Soil 12/30/13 Soil 12/30/13 Soil 12/30/13 Soil Raportad in% Analysis Date 01/06/14 10:45 01/06/14 10:45 01/06/14 10:45 01/06/14 10:45 Organic/Ash Content Burn Temperature 440 C Per ASTM D2974 Report tor XS97 Result 99.60 99.10 99.38 99.33 ANALYTICAL/& RESOURCES. INCORPORATED GEOTECHNICAL ANALYSIS DATA SHEET Total Solids by Method ASTM D2974 Data Release Authorized:r Reported: 01/17 /14 Date Received: 12/30/13' Page 1 of 1 Client/ ARI ID KPG 18-01 B-2 S-4 XS97A 13-28262 KCHA 29-03 8-3 S-3 XS978 13-28263 KCHA 29-03 B-2 S-3 XS97C 13-28264 KCHA 29-03 8-1 S-3 XS97D 13-28265 QC Report No: XS97-GeoDesign Inc Project: Date Analysis Sampled Matrix Date Result 12/30/13 Soil 01/06/14 10: 45 7 9. 64 12/30/13 Soil 01/06/14 10: 45 79.42 12/30/13 Soil 01/06/14 10:45 81.30 12/30/13 Soil 01/06/14 10: 45 80.93 Reported in % Report for XS97 ANALYTICAL IA RESOURCES. INCORPORATED ACRONYMS ACRONYMS ADS ASTM ATB BGS CEC EPA g gpm CPS HMA H:V IBC KCHA kN/m' MCE MSE OSHA pcf pci psf PVC SPT SWDM wss [fflDESIGNt advanced drainage system American Society for Testing and Materials asphalt-treated base be low ground surface cation exchange capacity U.S. Environmental Protection Agency gravitational acceleration (32.2 feet/second') gallons per minute global positioning system hot mix asphalt horizontal to vertical International Building Code King County Housing Authority kilonewtons per square meter maximum considered earthquake mechanically stabilized earth Occupational Safety and Health Administration pounds per cubic foot pounds per cubic inch pounds per square foot polyvinyl chloride standard penetration test Surface Water Design Manual DRAFT Washington Standard Specifications for Road, Bridge, and Municipal Construction (201 2) KCHA-29-03:021814 ! (f1D0ES1GN~----- REPORT OF GEOTECHNICAL ENGINEERING SERVICES Geologic Hazard Report· Update Vantage Point Apartments -Multi-Family Rental Project Vantage Glen Community 17901 105" Place SE Renton, Washington For Vantage Point Apartments LLC c/o King County Housing Authority January 16, 2014 (Update) February 27, 2013 (Original) GeoDesign Project: KCHA-29-03 \ ~ (l'.&0ESIGN~-----------~ January 16, 2014 Vantage Point Apartments LLC c/o King County Housing Authority 600 Andover Park West Tukwila, WA 98188 Attention: Mr. Tim Locke Report of Geotechnical Engineering Services Geologic Hazard Report -Update Vantage Point Apartments -Multi-Family Rental Project Vantage Glen Community 17901 1 05'" Place SE Renton, Washington GeoDesign Project: KCHA-29-03 GeoDesign, Inc. is pleased to present this updated geologic hazard report for the undeveloped King County Housing Authority (KCHA) property located north and east of the KCHA Vantage Glen community in Renton, Washington. Geologic Hazard Areas were identified on the site in accordance with the Title 21 A of the King County Zoning Code (2005). The geologic hazards identified on site include Erosion and Steep Slope Hazard Areas. The hazard areas appear stable and no landslides or slope failures were mapped or observed on the property. Historical aerial photographs indicate that the site topography, including the Geologic Hazard Areas, is the result of past grading activities associated with aggregate mining. We anticipate that based on the past grading activities the steep slope can be re-graded (altered) in accordance the provisions of King County Zoning Code Section 21 A.24. 31 O.D.2. This report has been prepared in accordance with the scope presented in our proposal dated November 14, 2013 and the KCHA Consultant Services Task Order dated November 25, 2013. • • • 10700 Meridian Avenue North, Suite 210 I Seattle, WA 98133 I 206.838.9900 www.geodesigninc.com We appreciate the opportunity to be of service to you. Please contact us if you have questions regarding this report. Sincerely, GeoDesign, Inc. Thomas A. Tobin, P.E. Principal Engineer cc: Ms. Pam Derry, Tonkin/Hoyne Architecture & Urban Design (via email only) Mr. Alberto Cisneros, KPFF Consulting Engineers (via email only) Ms. Anna Nelson, Van Ness Feldman LLP (via email only) TAT:kt Attachments One copy submined (via email only) Document ID: KCHA-29-03-011614-geor-GeolHaz.docx © 2014 GeoDesign, Inc. All rights reserved. •DESIGN~ 2 KCHA-29-03:011614 TABLE OF CONTENTS 1.0 2.0 3.0 4.0 5.0 INTRODUCTION SURFACE CONDITIONS 2. 1 Historical Aerial Photographs SITE GEOLOGY GEOLOGIC HAZARDS 4. 1 King County Geologic Critical Areas RECOMMENDATIONS AND CONCLUSIONS S. 1 Summary of Geologic Hazard Areas 5.2 REFERENCES Geotechnical Considerations FIGURES Vicinity Map Site Plan 1 985 Aerial Photograph of Vantage Glen Site Site Area Modified by Previous Legal Grading Existing Steep Slope and Erosion Hazard Areas New Steep Slope and Erosion Hazard Areas (aDESIGN~ PAGE NO. 1 2 2 3 3 4 4 4 6 Figure l Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 KCHA·29·03:0l l 614 1.0 INTRODUCTION The Vantage Glen community is located south and west of the intersection of SE 180'h Street and 108'h Avenue South (Figure 1 )_ The existing community consists of single-family manufactured homes and a community center. King County Housing Authority (KCHA) owns the two undeveloped parcels located to the north and east of the existing Vantage Glen community (Figure 1 ). The parcel numbers are 3223059362 and 3223059363 and for the purposes of this report will be referred to as Parcel "A" and Parcel "B", respectively (Figure 2). Parcel "B" encompasses the steep slope portion of the project site. Combined, the two undeveloped parcels form an L-shaped area that is approximately 5 acres in size. The site is bordered by 1 05'" Place SE on the east, SE 180'h Street and an apartment complex on the north, and the KCHA Vantage Glen residential community to the west and south (Figure 2). Short platting of the property was completed prior to the area being annexed into the City of Renton. We understand that the property can be developed under the King County Land Use Codes. The proposed development includes the construction of multi-family housing with associated parking areas and access roadways that will require site grading activities adjacent to the sloped areas of the site. Geotechnical services were required to identify, delineate, and evaluate geologic hazards on the site, as well as to identify areas of the site that have been modified by previous legal grading activities in order to address the King County Land Use Codes addressing development on or adjacent to Geologic Hazard Areas. The results of our study are provided below. 2.0 SURFACE CONDITIONS The project site is undeveloped. Parcel "A" is vegetated with grass that is maintained through regular mowing. Parcel "B" encompasses the steep slope area, which is vegetated with trees, brush, and grass. The ground surface in the project area slopes upwards to the south from SE 180'h Street and upwards to the west from 1 05'h Place SE to a ridge that generally defines the western and southern boundary between Parcels "A" and "B" (Figure 2). Within Parcel "A" the slope up from 1 05'" Place SE and SE 1 80'h Street to the ridge varies in height from approximately 1 0 to 16 feet and the inclination is less than 40 percent. The slope rises quickly but is generally less than 1 5 feet in height south of SE 1 80"' Street on the south side of Parcel "A" The inclination of the slope that extends up to the ridge from the roadway decreases to the west and north (Figure 2). &DESIGN~ KCHA-29-03:011614 Within Parcel "B," and to the west and south of the ridge, the ground surface slopes down to a 10-to 15-foot-wide bench that was created within the middle portion of the slope (Figure 2). Beyond the benched area the slope continues down to the backyards of the Vantage Glen community homes on 104'h Avenue SE and SE 181" Street. The slope gradients along the western and southern portion of Parcel "B'' vary from 15 percent to as much as approximately 60 percent, with a change in elevation varying from 1 O feet to approximately 40 feet. 2. I HISTORICAL AERIAL PHOTOGRAPHS We located and reviewed historical aerial photographs ofthe KCHA Vantage Glen project site dating from 1936 through 2004. The photographs provide evidence of historical grading activities that have modified the site. From 1936 through 1960 the site area was generally in a natural condition and adjacent to it were scattered residential homes and developed areas. Mining of sand and gravel began on the project site and the area occupied by the existing Vantage Glen community property sometime between 1960 and 1968. Mining continued through 1974, and the slopes around the perimeter of the site and adjacent Vantage Glen community appear to have been engineered with several benches cut into the slope to control surface water runoff and for stability purposes. No significant mine slope failures were observed in the aerial photographs. Mining activity ceased sometime prior to 1985. The 1985 aerial photograph (Figure 3) shows the site in the process of being developed for the existing manufactured home community. The project area and the adjacent Vantage Glen community area are being graded and the roadways appear to be paved, but no structures are present. By 1990 the Vantage Glen community has been developed and the project site is vegetated. The private apartment complex to the north of the project site is also present and appears to have been constructed by benching it into the hillside. The photographs indicate that the entire site topography and the surrounding slopes are a result of previous site grading activities associated with sand and gravel mining and the development of the Vantage Glen community (Figure 4). 3.0 SITE GEOLOGY Surficial geologic information for the area was obtained from the geologic map of King County (Booth, Troost, Wisher, 2007). The surficial geology within the site is mapped as Glacial Till, which is typically composed of very dense, silty sand with gravel to sandy silt with gravel, cobbles, and occasional boulders. However, the historical use as an aggregate mine indicate that the till cap is shallow and the underling material that was mined was likely Glacial Advance Outwash composed of sand and gravel. Preliminary results of soil borings for the geotechnical investigation for this project generally confirm the mapped geology. A thin layer of disturbed material mantles the site and is underlain by dense glacial till underlain by Glacial Advance Outwash deposits varying from silt to silty sand and gravel. &DESIGN~ 2 KCHA-29-03:011614 There are no landslides or landslide deposits mapped within or adjacent to the property. We did not observe evidence indicating landsliding or significant slope stability issues anywhere within the property. We completed a reconnaissance of the site in February 2013 and again in December 2013 to observe the existing conditions, soil exposures, and slope conditions. The surficial soil exposed at isolated locations within the parcels and observed in shallow excavations generally consists of silty sand with gravel, which is consistent with the mapped geology. Groundwater seeps or springs were not observed on the site other than Panther Lake Ditch, which is located west of the existing Vantage Glen community. 4.0 GEOLOGIC HAZARDS This report is limited to identifying and evaluating the Geologic Hazard Areas present at the site. Geologic hazards are identified at the site based on King County Zoning Code Chapter 21A.24 - Critical Areas. 4.1 KING COUNTY GEOLOGIC CRITICAL AREAS King County Geologic Critical Areas include: Erosion, Landslide, Steep Slope, Seismic, Volcanic, and Coal Mine Hazards. Other types of Critical Areas include: Flood Hazard Areas, Critical Aquifer Recharge Areas, Wetlands, Aquatic Areas, and Wildlife Habitat Conservation Areas. Based on established maps, there are no Volcanic, Coal Mine, Seismic, or Critical Aquifer Recharge Areas within or adjacent to the project site. Based on our reconnaissance of the project site and adjacent property, there are no Landslide Hazard Areas within or adjacent to the project site. Steep Slope Hazard Areas are defined by King County Zoning Code Section 21A.06.1230 as "an area on a slope of forty percent inclination or more within a vertical elevation change of at least ten feet. For the purpose of this definition, a slope is delineated by establishing its toe and top and is measured by averaging the inclination over at least ten feet of vertical relief." The steep slopes on the project site that meet the criteria are identified on Figures 5 and 6. Figure 5 delineates the existing Steep Slope Hazard Areas. Because the site slopes are created by past legal grading, the steep slopes can be re-graded (altered) in accordance the provisions of King County Zoning Code Section 21 A.24.31 O.D.2. Re-grading will occur in the upper zone of the steep slope area. The new steep slope areas that will remain following re-grading are delineated on Figure 6. The majority of the site is also classified as an Erosion Hazard Area. 3 KCHA-29-03:011614 5.0 RECOMMENDATIONS AND CONCLUSIONS 5.1 SUMMARY OF GEOLOGIC HAZARD AREAS Geologic Hazard Areas identified on site, in accordance with the definitions in the King County Zoning Code, are summarized in the table below and shown on Figures 5 and 6. Geologic Hazard Area Erosion Steep Slope Hazards Landslide Hazards 5.1.1 Erosion Hazard King County Zoning Code (Chapter 21 A.24) Yes Yes · >40 percent and > 10 feet hi h No The Erosion Hazard is applicable to the entire site and can be addressed through a Temporary Erosion and Sedimentation Control Plan and establishing proactive Best Management Practices during construction. The Erosion Hazard should not impact the planned development of the site. 5.1.2 Steep Slope Hazard The Steep Slope Hazard Areas, as defined by King County Zoning Code, are shown on Figure 5 for present conditions and Figure 6 for post-grading conditions. King County Zoning Code Section 21 A.24.31 0 describes development standards and alterations for Steep Slope Hazard Areas. This code section describes that a buffer be established from all edges of the Steep Slope Hazard Area. Therefore, we recommend establishing al 0-foot-wide buffer from the top of the Steep Slope Hazard Area. The top of the Steep Slope Hazard Area and the 1 0-foot buffer are shown on Figure 6 for post-grading conditions. No buffer is necessary where the steep slope is supported by a properly engineered retaining wall, in our opinion. As shown on Figure 6, a retaining wall will be constructed along a portion of the crest of the steep slope. No buffer will be necessary behind the retaining wall. Recommendations for design and construction of this retaining wall are included in the geotechnical design report for this project. King County Zoning Code Section 21A.24.200 requires that a building setback be established from the edges of all critical area buffers or from the edges of all critical areas, if no buffers are required. The code mandates a setback of l 5 feet. The code allows the following improvements within the building setback area: landscaping, uncovered decks, building overhangs not extending more than 18 inches into the setback area, impervious ground surfaces such as driveways and patios, and utilities as long as the excavation for installation of the utilities avoids impacts to the critical area and buffer. The proposed access roadway, sidewalks, and drainage utility are all allowed improvements in the building setback area, in our opinion. 5.2 GEOTECHNICAL CONSIDERATIONS Our reconnaissance of the site indicates that the existing slopes are stable and surficial evidence of instability was not observed. Preliminary results of subsurface explorations are consistent with the mapped geology and indicate the area is underlain by a surficial layer offill underlain by glacially consolidated deposits of Glacial Till and Glacial Advance Outwash. &DESIGN~ 4 KCHA-29·03:011614 Re-grading of the site that does not increase the existing slope inclinations in excess of 50 percent will not adversely impact the slope stability of the site and will not adversely impact the slope stability on adjacent properties or of the Steep Slope Hazard Areas_ Re-graded surfaces at the top of slopes should be graded to drain back from the top of slopes. Stormwater drainage should be collected and routed through to the site stormwater management facilities. • •• We appreciate the opportunity to provide our services on this project. Please call if you have questions concerning the information provided in this report. Sincerely, GeoDesign, Inc. --rl >«c~,J A I c_f c '.,"- Thomas A. Tobin, P.E. Principal Engineer BDESIGN~ Signed Ol /16/2014 5 KCHA-29-03:011614 REFERENCES Booth, Derek B., Kathy A Troost, and Aaron P. Wisher (2007), Geologic Map of King County, Compiled March 2007, GeoMapNW, scale 1:100,000. King County Zoning Code -Chapter 21 A.24 -Critical Areas (3-2005). BDESIGN~ 6 KCHA-29-03:011614 FIGURES ... VICINITY MAP BASED ON AERIAL PHOTOGRAPH OBTAINED FROM GOOGL.E EARTH PRO" KCHA-29-03 N @ 0 2000 VICINITY MAP ;,. c, IJl(C,VercanA,,·ricu \,,r\·1 Su·t,·;·,J ~ ~ ,,,-a,·le 'tiA'IHIJJ VANTAGE POINT APARTMENTS c , JANUARY 2014 4000 FIGURE 1 cc ,;., ~111 ;:JG aJs ~9cc '·'' ,o~ 838 9~-Jr RENTON, WA ~=L __________ ___l __________ _L ___________________ _1_ ______ __J z 3lln~1.::1 > • < C z C ~ ~ ~ 0 z I w I "' I w ~ ------='---=-== =-if--=::..lL--=;;; Wt.. 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" u < SC < , 0 " ~ z ~ ,-----------www.geodesigninc.com I VANTAGE POINT APARTMENTS Wetland Report Prepared for: January 2014 King County Housing Authority VANTAGE POINT APARTMENTS Wetland Report Prepared for: January 2014 King County Housing Authority I :s \ Vantage Point Wetlands Study SUMMARY At the request of the King County Housing Authority (KCHA), Environmental Science Associates (ESA) delineated wetland boundaries and prepared this technical report for the proposed Vantage Point Apartments property, located in the City of Renton, Washington. The KCHA Vantage Point Apartments project is proposed on a vacant site on the south and west side of SE 180th Street and I 05th Place SE in the City of Renton. The proposal is to construct 77 units of affordable rental housing for low-income seniors, constructed in two buildings of 32 and 45 units. The buildings will be three-and four-story, woodframe construction with the majority of the parking provided under the proposed buildings. The property was annexed by the City of Renton in 2009 and subsequently subdivided in 20 I 0 (Short Plat Rec. No. 20100111900006). As provided in the Short Plat notes (Note 20 and 21) the proposed project is vested to the regulations that were in place prior to annexation, within the 2005 King County Critical Areas Ordinance (Title 2 lA.24). One wetland (Wetland A) was delineated on the Vantage Point Apartments property. Wetland A is an unmapped palustrine forested (PFO), slope wetland located at the northeast end of 104th Avenue SE and is approximately 550 square feet in size (see Figure 2). The wetland is located next to the base of a steep slope. Using the Washington State Department of Ecology wetland rating system, Wetland A was rated Category IV. The standard buffer width for a Category IV wetland in the urban growth area is 50 feet under King County Code 21A.24.325.A (2005). However, the 2005 King County Code requires extension of wetland buffers to 25 feet beyond the top of slope when wetlands are adjacent to steep slopes. In such cases, either the standard wetland buffer or the 25-foot buffer from top of slope applies, whichever is larger (KCC 21A.24.325.D.2). There is a break in the steep slope located approximately 40 feet upslope of Wetland A. The slope break is a topographic bench approximately 20 to 25 feet wide with a slope of approximately 15%. Extending the wetland buffer 25 feet upslope from this break results in a wetland buffer that is slightly larger than the standard 50-foot wetland buffer (see Figure 2). No impacts to Wetland A or its buffer are proposed. The proposed Vantage Point Apartments would be located approximately I 00 feet upslope of Wetland A (Figure 3). The proposed regrading of the adjacent slope, as allowed by King County Code (KCC) 21A.24.310D.2., will occur outside of the required 50-foot wetland buffer (approximately 10 to 30 feet upslope of the eastern edge of the buffer at the closest point; see Figure 3). ESA page 1 January 2014 Vantage Point Wetland, Study CONTENTS 1.0 PROJECT AUTHORIZATION AND SCOPE OF WORK ....................................................... 1 2.0 SITE AND PROJECT DESCRIPTION ....................................................................................... I 3.0 WETLAND DEFINITION AND REGULATIONS .................................................................... I 4.0 METHODS ..................................................................................................................................... 2 4.1 REVIEW OF EXISTING INFORMATION ............................................................................................. 2 4.2 ON-SITE INVESTIGATION .................................................................................................................. 2 4.2.1 Determining the Presence of Wetlands and Delineating Wetland Boundaries ......... 2 4.2.2 Classifying Wetlands .......................................................................................................... 3 4.2.3 Assessing Wetland Functions ........................................................................................... 3 5.0 FINDINGS ...................................................................................................................................... 3 5.1 EXISTING INFORMATION .................................................................................................................. 3 5.2 WETLANDS DETERMINATIONS ........................................................................................................ 4 5.2.1 Wetland A ............................................................................................................................. 4 5.3 UPLAND DESCRJPTION ...................................................................................................................... 5 5.4 WILDLIFE HABITATS ........................................................................................................................ 5 6.0 PROJECT IMPACTS AND REGULATORY CONSIDERATIONS ....................................... 5 7.0 LIMITATIONS .............................................................................................................................. 6 8.0 REFERENCES ............................................................................................................................... 7 FIGURES AND PHOTOGRAPHS ........................................................................................................... 9 APPENDIX A: METHODS USED TO EV ALU ATE WETLAND CHARACTERISTICS APPENDIX B: COMMON AND SCIENTIFIC NAMES OF PLANTS AND THEIR WETLAND INDICATOR STATUS APPENDIX C: WETLAND DETERMINATION DATA FORMS AND WETLAND RATING FORM LIST OF FIGURES I Project Vicinity and Mapped Wetlands/Streams 2 Wetland Delineation 3 Proposed Site Layout ESA January 2014 page 11 Vantage Point Wetlands Study 1.0 PROJECT AUTHORIZATION AND SCOPE OF WORK At the request of the King County Housing Authority (KCHA), Environmental Science Associates (ESA) delineated wetland boundaries and prepared this technical report for the proposed Vantage Point Apartments property, located in the City of Renton, Washington. The boundaries of the study area were established based on maps provided by the KCHA. The Scope of Work for this project included wetlands delineations, an assessment of wetland functions, and an evaluation of project impacts and permitting considerations for wetlands and associated buffer areas. 2.0 SITE AND PROJECT DESCRIPTION The KCHA Vantage Point Apartments project is proposed on a vacant site on the south and west side of SE 180th Street and 105th Place SE in the City of Renton (Figure 1 ). The site is located directly across from the Fred Meyer store at Benson and Carr Road (east), adjacent to KCHA's Vantage Glen senior housing community (south and west), and adjacent to an existing multi- family housing development (north). The proposal is to construct 77 units of affordable rental housing for low-income seniors, constructed in two buildings of32 and 45 units. The buildings will be three-and four-story, woodframe construction with the majority of the parking provided under the proposed buildings. The property is currently undeveloped, consisting of a mowed grass area abutted to the south and west by a steep, forested ravine. The existing Vantage Glen and Vantage Heights developments lie south of the ravine. Panther Creek crosses the southwestern part of the Vantage Glen site, approximately one-quarter mile from the Vantage Point Apartments property (Figure I). The property was annexed by the City of Renton in 2009 and subsequently subdivided in 2010 (Short Plat Rec. No. 20100111900006). As provided in the Short Plat notes (Note 20 and 21), the proposed project is vested to the regulations that were in place prior to annexation, within the 2005 King County Critical Areas Ordinance (Title 2 lA.24). 3.0 WETLAND DEFINITION AND REGULATIONS The characteristics of an area that result in its classification as "wetland" have been formally defined by federal and state agencies, as described in Appendix A. Numerous federal, state, and local regulations govern development and other activities in or near wetlands; at each level, there are typically several agencies charged with such powers (Ecology, 1994). Specific regulatory implications concerning the subject property are summarized later in this report. ESA page 1 January 2014 Vantage Point Wetlands Study 4.0 METHODS Two levels of investigation were conducted for the analysis of wetlands on the subject property: a review of existing information and an on-site investigation. 4.1 Review of Existing Information A review of existing literature, maps, and other materials was conducted to identify wetlands or site characteristics indicative of wetlands on the subject property. These sources can only indicate the likelihood of the presence of wetlands; actual wetland determinations must be based upon data obtained from field investigations. Several documents were reviewed: • U.S. Geological Survey (USGS), 2007 King County iMAP-Hydrographic Information, King County, WA; • Soil Survey of King County Area, Washington (Snyder et al. 1973); • National Wetland Inventory, Renton quadrangle [U.S. Fish and Wildlife Service (USFWS), 1988); • USFWS Online Mapper (USFWS, July 2007); and • National Resources Conservation Service (NRCS), National Hydric Soil List by State: Washington (Feburary 2007). 4.2 On-site Investigation 4.2. 1 Determining the Presence of Wetlands and Delineating Wetland Boundaries Methods defined in the Washington State Wetlands Identification and Delineation Manual (Ecology, 1997), a manual consistent with the US. Army Corps of Engineers Wetlands Delineation Manual (Enviromnental Laboratory, 1987), were used to determine the presence and extent of wetlands on the subject property. Washington State and all local govermnents must use the state delineation manual to implement the Shoreline Management Act and/or the local regulations adopted pursuant to the Growth Management Act. The methodology outlined in the manual is based upon three essential characteristics of wetlands: (I) hydrophytic vegetation; (2) hydric soils; and (3) wetland hydrology. Field indicators of these three characteristics must all be present in order to determine that an area is a wetland (unless problem areas or atypical situations are encountered). The "routine on-site determination method" was used to determine the wetland boundaries. The routine method is used for areas equal to or less than five acres in size, or for larger areas with relatively homogeneous vegetative, soil, and hydrologic properties. ESA page2 January 2014 Vantage Point Wetlands Study Fom1al data plots were established where information regarding each of the three wetland parameters (vegetation, soils, and hydrology) was recorded. This information was used to distinguish wetlands from non-wetlands. If wetlands were determined to be present on the subject property, the wetland boundaries were delineated. Wetland boundaries were identified with sequentially numbered colored flagging imprinted with the words WETLAND BOUNDARY. Data plot locations were also marked with colored flagging (white with red dots). The methods used to assess wetland characteristics are described in greater detail in Appendix A. Please note that common plant names are used throughout this text; the scientific names are presented in Appendix B. 4.2.2 Classifying Wetlands Two classification systems are commonly used to describe wetlands. The hydrogeomorphic (HGM) system describes wetlands in terms of their position in the landscape and the movement of water in the wetland (Brinson, 1993). The U.S. Fish and Wildlife Service classification system (Cowardin et al., 1979) describes wetlands in terms of their vegetation communities; these include, for example, emergent, scrub-shrub, and forested community types. 4.2.3 Assessing Wetland Functions Wetlands play important roles that provide valuable benefits to the environment and society. Because detailed scientific knowledge of wetland functions is limited, evaluations of the functions of individual wetlands are somewhat qualitative and dependent upon professional judgment. For this project, wetland functions were assessed using the Ecology Wetland Rating System for Western Washington (Hruby, 2004). 5.0 FINDINGS 5.1 Existing Information No wetlands are mapped on the Vantage Point property by King County or WDFW (Figure 2). The Soil Survey of King County Area (Snyder et al., 1973) indicates the Alderwood series occurs on the project site. Alderwood soils are made up of moderately well drained soils that have a weakly to strongly consolidated substratum at a depth of 24 to 40 inches. These are upland soils that formed under conifers in glacial deposits. Annual precipitation is 35 to 60 inches, most of which is rainfall occurring between October and May. The mapped soils are not considered hydric; however, hydric inclusions such as Norma, Bellingham, Seattle, Tukwila, and Shalcar soils may occur in some areas. ESA page 3 January 2014 Vantage Point Wetlands Study 5.2 Wetlands Determinations The following sections describe the results of the field investigation conducted on August 28, 2007, by ESA biologists Rachel Hulscher and Lara Thoreson on the subject property. These sections describe the one wetland found on the site (Wetland A), upland habitats, and wildlife observations. Two data plots were established within relatively uniform areas of vegetation on the site. Data sheets for each of the formal data plots evaluated for this project are provided in Appendix C. Figure 2 shows the approximate location of the wetland. The wetland flags were not surveyed, but the location of the 8-inch PVC pipe at the downslope portion of the wetland was surveyed. Therefore, the location of the wetland is accurate and the size and dimensions are approximated based on site measurements. 5.2.1 Wetland A Overview. Wetland A is located east of 104'h Avenue SE between a residential area and an undeveloped hillside. This is a hillside seep that drains west, along the slope gradient. The surface water then enters into a stormwater drain. Wetland A is a palustrine forested slope wetland approximately 550 square feet in size (Photo 2). Data plot DP-I characterizes this wetland. Hydrology. The main source of water for Wetland A is groundwater. The adjacent hillside is a maintained grass lawn that provides additional runoff to the wetland. Free water was observed in the soil pit eight inches from the soil surface during the site visit. The soil was saturated to the surface throughout the wetland. Soils. Wetland soils were a black (lOYR 2/1) sandy, mucky loam to eight inches in depth, and a dark greenish gray (GI 4/IOY) sandy clay loam between eight and 12 inches in depth. These soils were not consistent with the mapped Alderwood soil type. Low chroma and gleyed soil colors are indicators ofhydric soils. Vegetation. Canopy cover in Wetland A is dominated by red alder, and the dominant understory contains a combination of Himalayan blackberry and bittersweet nightshade. Other species present in the wetland include: bigleaf maple, black cottonwood, Indian plum, salmonberry, evergreen blackberry, and reed canarygrass. Wetland Functions. The results of the functions assessment for the wetland areas are presented in Appendix C. Wetland A received low scores for water quality, hydrologic, and habitat functions. The wetland does have the potential to reduce water velocity and erosion due to the presence of dense, woody vegetation. Habitat functions merited a low score ( 6) due to homogeneous habitat, lack of special or priority habitat features, absence of adjacent wetlands, and low presence of wildlife and buffer habitat. ESA page4 January 2014 Vantage Point Wetlands Study 5.3 Upland Description Upland areas adjacent to Wetland A are characterized by a deciduous forest with a dense understory, while developed lots contain lawn and landscape plantings. Bigleaf maple and red alder dominate the forest canopy and the understory is dominated by Indian plum. Himalayan blackberry is present in dense patches in the upland area as well. Soils are mostly fill material and contain cobbles up to two inches in diameter. Upland soils are a dark grayish brown (1 OYR 4/2) loam near the soil surface with a light olive brown (2.5Y 5/4) silty clay between four and 16 inches below ground. Data Plot DP-2 describes the upland area (Appendix D). 5.4 Wildlife Habitats Wildlife habitats in the vicinity of the Vantage Point site include mixed coniferous-deciduous forest, the Panther Creek riparian zone, open grassy areas, and renmant vegetation within residential developments. These areas offer habitat structures such as multiple canopy layers, snags, and downed woody debris. The quality of habitats is somewhat diminished by the presence of invasive plant species (primarily Himalayan blackberry), along with noise and disturbance from roads, commercial areas, and residential land uses. 6.0 PROJECT IMPACTS AND REGULATORY CONSIDERATIONS No impacts to Wetland A or its buffer are proposed. The proposed Vantage Point Apartments would be located approximately 100 feet upslope of Wetland A (Figure 3). The proposed regrading of the adjacent slope, as allowed by King County Code (KCC) 2 lA.24.31 OD.2., will occur outside of the required 50-foot wetland buffer (approximately 10 to 30 feet upslope of the eastern edge of the buffer at the closest point; see Figure 3). As stated earlier, the proposed project is vested to the 2005 King County critical areas ordinance. King County Code 21A.24.318 requires wetlands to be rated using the Washington State Department of Ecology wetland rating system (Hruby, 2004). Using this system, Wetland A meets the criteria for a Category IV wetland. The standard buffer width for a Category IV wetland in the urban growth area is 50 feet under King County Code 21A.24.325.A (2005). However, the 2005 King County Code requires extension of wetland buffers to 25 feet beyond the top of slope when wetlands are adjacent to steep slopes. In such cases, either the standard wetland buffer or the 25-foot buffer from top of slope applies, whichever is larger (KCC 21A.24.325.D.2). There is a break in the steep slope located approximately 40 feet upslope of Wetland A. The slope break is a topographic bench approximately 20 to 25 feet wide with a slope of approximately 15%. Extending the wetland buffer 25 feet upslope from this break results in a wetland buffer that is slightly larger than the standard 50-foot wetland buffer (see Figure 2). ESA page 5 January 20 14 Vantage Point Wetlands Study 7.0 LIMITATIONS Within the limitations of schedule, budget, scope-of-work, and seasonal constraints, we warrant that this study was conducted in accordance with generally accepted environmental science practices, including the technical guidelines and criteria in effect at the time this study was performed, as outlined in the Methods section. The results and conclusions of this report represent the authors' best professional judgment, based upon information provided by the project proponent in addition to that obtained during the course of this study. No other warranty, expressed or implied, is made. ESA page 6 January 2014 Vantage Point Wetlands Study 8.0 REFERENCES Brinson, M. August 1993. A Hydrogeomorphic Classification/or Wetlands. U.S. Army Corps of Engineers, Wetlands Research Program. Cowardin, L.M., V. Carter, F.C. Golet, and E.T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. FWS/OBS-79/31. U.S. Fish and Wildlife Service. Ecology (Washington State Department of Ecology). 1991. Shoreline Management Handbook: First Edition. Publication No. 90-45. Olympia, Washington. Ecology (Washington State Department of Ecology). 1992. The Growth Management Act and the State Environmental Policy Act: A Guide to Interrelationships. Publication No. 92- 07. Olympia, Washington. Ecology (Washington State Department of Ecology). 1994. Wetlands Regulations Guidebook. Publication No. 88-5. Olympia, Washington. Ecology (Washington State Department of Ecology). 1997. Washington State Wetlands Identification and Delineation Manual. Publication No. 96-94. Olympia, Washington. Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. Technical Report Y-87-1. U.S. Army Engineer Waterways Experiment Station, Vicksburg, Massachusetts. EPA (Environmental Protection Agency) and Corps (US Army Corps of Engineers). June 5, 2007. Clean Water Act Jurisdiction Following the US Supreme Court's Decision in Rapanos v. United States & Carabell v. United States. Federal Register. 1982. Title 33: Navigation and Navigable Waters; Chapter II, Regulatory Programs of the Corps of Engineers. Vol. 47, No. 138, p. 31810. U.S. Government Printing Office, Washington, DC. Federal Register. 1986. 33 CFR Parts 320 through 330: Regulatory Programs of the Corps of Engineers; Final Rule. Vol. 51, No. 219, pp. 41206-41260. U.S. Government Printing Office, Washington, DC. Federal Register. 1988. 40 CFR Part 230. Guidelines for Specification of Disposal Sites for Dredged or Fill Material. Vol. 45, No. 249, Pages 85336-85357. U.S. Government Printing Office, Washington, DC. Federal Register. 1994. Changes in Hydric Soils of the United States. July 13. Washington, DC. Hitchcock, C.L., and A. Cronquist. 1973. Flora of the Pac/fie Northwest: An Illustrated Manual. University of Washington Press, Seattle, Washington. ESA page 7 January 2014 Vantage Point Wetlands Study Hruby, Thomas. 2004. Washington State Wetland Rating System for Western Washington: Wetland Rating Form. Washington State Department of Ecology. August. Munsell Color. 2000. Munsell Soil Color Charts. GretagMacbeth, New Windsor, New York. NRCS (Natural Resources Conservation Service). National Hydric Soil Lists by State: Washington. Available online at http://soils.usda.gov/use/hydric/lists/state.html. NRCS (Natural Resources Conservation Service). 1998. Field Indicators of Hydric Soils in the United States, Version 4.0. G.W. Hurt, P.M. Whited, and R.F. Pringle (eds.), United States Department of Agriculture, Ft. Worth, Texas. Snyder, D. E., P. S. Gale, and R. F. Pringle. 1973. Soil Survey Report of King County Area, Washington. United States Department of Agriculture Soil Conservation Service, in Cooperation with the Washington Agricultural Experiment Station. 61 pages. USFWS (U.S. Fish and Wildlife Service). 1988. National Wetlands Inventory. Renton Quadrangle. U.S. Department of the Interior. USFWS (U.S. Fish and Wildlife Service). 1988. National List of Plant Species that Occur in Wetlands: Northwest (Region 9). Biol. Rpt. 88(26.9). United States Department of Interior, Washington, DC. USFWS (U.S. Fish and Wildlife Service). 1993. 1993 Supplement to List of Plant Species that Occur in Wetlands: Northwest (Region 9). USFWS (U.S. Fish and Wildlife Service). July 2007. Wetlands Online Mapper. Available online at http://wetlandsfws.er.usgs.gov/wtlnds/launch.html. Accessed August 2007. Vepraskas, M.J. 1999. Redoximorphic Features for Identifying Aguie Conditions. Technical Bulletin 301. North Carolina Agricultural Research Service, North Carolina State University, Raleigh, North Carolina. ESA page 8 January 2014 Vantage Point Wetlands Study FIGURES AND PHOTOGRAPHS ESA page 9 January 2014 ai "> Q) "O "O ri 0 i "O X E ui E "' ~ VJ "'I "O C: .!!! oi $'. "O I 8- Q. "' ::;; I :?;, ·1: ·.:; ~I (.) Q) B ~I .2> u. vi "O X ::;; .:: C: ·o 0.. Q) C> .!!! C: "' > <(I u I ::.:: <DI 0 (0 "' V ~ ~ X N vi ~ ·e 0.. ui C, ui ~ ::i .c ro 0.. Feet SOURCE: King County 2002 , 2006; WDFW 2006 Study Area 1:,:./··m PHS Wetlands ~ SAO Wetlands Roads Va ntage Glen and Vista Heights. 207462 Figure 1 Project Vicinity and Previou sly Mapped Wetlands/Streams Renton /King County, WA i' .!. ~ L \ \~ \\ \I -ii f ~I I - I i!/ ~ :, ' l ft I I ft t i ',\ t J \~ \ ; \\ § \\ ' WETLAND PLAN 25 I I I ,, I~ I 1/ r ,; I' SCALE Fab-) 50 I L1 I I I I I 200 IN I t1 I W ETLAND A APPR OX. 550 S F W ETLAND A STANDA RD 50' BUFFER W ETLAN D A BUFFER 25' F R O M TOP O F SLOPE LEGEND: c=J STEEP SLO PES- GREATER TH AN 4096 -W ETLAND @ DP-1 DATA PLOT --------------------------------------------------Vantage G len andVisla Heights . 0207462 SOURCE: Ki ng County 2002, 2006;KCHA , 2013; WDFW 2006 Figure 2 Wetla nd De lineatio n (U p dat e d 12-2013) & St eep S lopes City of Rent on K ing Cou nty, Washi ngt o n ! ! 1 ~~·~:~,-<-~:~i;·:<.-.' :-, '> ,.,_ ',> ' / _:;; '-·.\\ I "'. ,. . ' I <. 'J\' I ·_' ·~ ', "'{ I / \.'.\ .. \ I )1( I •. '/'··· ' ,· ' .Fl/ I \ . , , . , ,. '. 1 . .1 i1 'I , ', \·.·~ ·I·/ !t,.ll I ' I. I' I. : I I " .f,J, .. ·.·.:' / ) ', ; •·· .. s)(f / ;J· .. h ,· ,, ', __ -~_j.J~' ·_'J!_,;,~,r-f . .'I : ·, '1,''T)1 , I"·,/ ' ·.,. ·-,. l ,/ .. ( ·1 y /.,. i ::. / ' '·· -PROPOS ~ ~{::'. , :CO,NSTRLJCTJO .• '"" <::::::' ... .!r·>·>::~::·-.,.< ' , 'lift,.._, --' WETLAND-A ~ . ", ' , ' ... ' ' -,~ ' ,' STD. so•·,.. ,, .. ~ / BUFF-t;R' • ',,. \\ I -~ c._ ,, \' ,' . WETLANO'A '~' ' ,' WETLAND A . l3UF!,ER 25-' ',, \ / ,' 'ffiOMoOF' i',. ' I • .. l.. ·. ' /• I ' c.QF·SLOl"E: / ~ ' ' ' . \ , , • ' I,, I / \ \ I I,....,,/ I I I , , I, I '/ , ;, i I ' I ,I I/ I ~\. ' . I / ·1''·1' ', I \ I / I / /' " ,. 'e , . l I ", · .. I . • 'l"1 . , ;, ", TOP'·OF/3LOPE, / I J ', I }; 1 ·' , // 1 I ' .), -L, / / 1f ' e'; 'f ', 1 / 1' '/ ' ' 'I I ' / ' / 11 ', / , _..,, :;_:,,. . I , ' i, ' ,) ~I \ -~ /; ! ll I , I. I iC:., -· / ' i ' '/,' "J .... ·-~ '•(i,' ""-----.... ..L -. _,I ,·y,· ,,,.._ ..... 1 l_ I / '1"7"717'".'?'-R'ROEjOS~D ! ' , j , .·' · CON~:rRt,JCTIQN . , "I . , , . l WETLAND PLAN r~ "' 1l. f I I \' . ''~ .. ~·'"· '· . ~· = --·:_ ·:.c........ ~ .> > ..--'", LEGEND I I lil'l'III Wetland I ® oe-1 Data Plot Standard 50' -----Wetland Buffer -----Wetland Buffer 25' From Top of Slope I '° N -:~~-~-+. -~: ~ :..~- 11 ,'"' ~~:~:~ ~C'c,c/t rt C C: , 1 =i,.., I ---::. 100 N I ! SOURCE: King County 2002, 2006; KCHA, 2013: WOFW 2006 Vantage Glen and Vista Heights. 0207462 Figure 3 Proposed Site Layout City of Renton King County, Washington Photo 1 : Looking northwest over Vantage Glen. (August 28, 2007) Photo 2: Looking east toward Wetland A , a PFO s lop e wetl and . Flags A -1 th rough A-6 were hung to identify th e approximate wet land boundary. Seepage from the hillslope prov id es a water source to th e wetland. Water flows through a drain at the west s ide of the wetl and at the base of the s lop e . (August 28 , 2007) ESA January 2014 Vantage Point Wetlands Study APPENDIX A: METHODS USED TO EVALUATE WETLAND CHARACTERISTICS Appendix A Vantage Point Wetlands Study Wetland Definition Wetlands are formally defined by the U.S. Army Corps of Engineers (Corps) (Federal Register 1982), the Environmental Protection Agency (EPA) (Federal Register 1988), the Washington Shoreline Management Act (SMA) of 1971 (Ecology, 1991) and the Washington State Growth Management Act (GMA) (Ecology, 1992) as ... those areas that are inundated or saturated by suiface or groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs, and similar areas (Federal Register, l 982, 1986). In addition, the SMA and the GMA definitions add: Wetlands do not include those artificial wetlands intentionally created from non- wetland site, including, but not limited to, irrigation and drainage ditches, grass- lined swales, canals, detention facilities, wastewater treatment facilities, farm pond~, and landscape amenities, or those wetlands created after July 1, 1990 that were unintentionally created as a result of the construction of a road, street, or highway. Wetlands may include those artificially created wetlands intentionally created from non-wetland areas to mitigate the conversion of wetlands. Methods defined in the Washington Stale Wetlands Identification and Delineation Manual (Ecology, 1997), a manual consistent with the U.S. Army Corps of Engineers Wetlands Delineation Manual (Environmental Laboratory, 1987), were used to determine the presence and extent of wetlands on the subject property. Washington state and all local governments must use the state delineation manual to implement the SMA and/or the local regulations adopted pursuant to the GMA. The methodology outlined in the manual is based upon three essential characteristics of wetlands: (1) hydrophytic vegetation; (2) hydric soils; and (3) wetland hydrology. Field indicators of these three characteristics must all be present in order to determine that an area is a wetland (unless problem areas or atypical situations are encountered). These characteristics are discussed below. Vegetation Plants must be specially adapted for life under saturated or anaerobic conditions to grow in wetlands. The U.S. Fish and Wildlife Service (USFWS) has determined the estimated probability of each plant species' occurrence in wetlands and has accordingly assigned a "wetland indicator status" (WIS) to each species (USFWS, 1988, 1993). Plants are categorized as obligate (OBL ), facultative wetland (FACW), facultative (FAC), facultative upland (F ACU), upland (UPL), not listed (NL), or no indicator status (NI). Definitions for each indicator status are listed in Appendix B. Species with an indicator status of OBL, F ACW, or FAC are considered adapted for life in saturated or anaerobic soil conditions. Such species are referred to as "hydrophytic" vegetation. A ( +) or (-) sign following the WIS signifies greater or lesser likelihood, respectively, of the species being found in wetland conditions. ESA Page A-1 January 2014 Vantage Point Wetlands Study Areas ofrelatively homogeneous vegetative composition can be characterized by "dominant" species. The indicator status of the dominant species within each vegetative stratum is used to determine if the plant community may be characterized as hydrophytic. The vegetation of an area is considered to be hydrophytic if more than 50% of the dominant species have an indicator status ofOBL, FACW, or FAC. Soils Hydric soils are indicative of wetlands. Hydric soils are defined as soils that are saturated, flooded, or ponded long enough during the growing season to develop anaerobic conditions in the upper part of the soil profile (Federal Register, 1994). The Natural Resources Conservation Service (NRCS), in cooperation with the National Technical Committee for Hydric Soils, has compiled lists of hydric soils (NRCS, 1995). These lists identify soil series mapped by the NRCS that meet hydric soil criteria. It is common, however, for a map unit of non-wetland (non-hydric) soil to have inclusions of hydric soil, and vice versa. Therefore, field examination of soil conditions is important to determine if hydric soil conditions exist. The NRCS has developed a guide for identifying field indicators ofhydric soils (NRCS, 1998). This list of hydric soil indicators is considered to be dynamic; revisions are anticipated to occur on a regular basis as a result of ongoing studies ofhydric soils. Anaerobic conditions create certain characteristics in hydric soils, collectively known as "redoximorphic features," that can be observed in the field (Vepraskas, 1999). Redoximorphic features include high organic content, accumulation of sulfidic material (rotten egg odor), greenish-or bluish-gray color (gley formation), spots or blotches of different color interspersed with the dominant or matrix color (mottling), and dark soil colors (low soil chroma) (NRCS, 1998; Vepraskas, 1999). Soil colors are described both by common color name (for example, "dark brown") and by a numerical description of their hue, value, and chroma (for example, I OYR 2/2) as identified on a Munsell soil color chart (Munsell Color, 2000). Soil color is determined from a moist soil sample. Hydrology Water must be present in order for wetlands to exist; however, it need not be present throughout the entire year. Wetland hydrology is considered to be present when there is permanent or periodic inundation or soil saturation at or near the soil surface for more than 12.5% of the growing season (typically two weeks in lowland Pacific Northwest areas). Areas that are inundated or saturated for between 5% and I 2.5% of the growing season in most years may or may not be wetlands. Areas inundated or saturated for less than 5% of the growing season are non-wetlands (Ecology, 1997). Indicators of wetland hydrology include observation of ponding or soil saturation, water marks, drift lines, drainage patterns, sediment deposits, oxidized rhizospheres, water-stained leaves, and local soil survey data. Where positive indicators of wetland hydrology are observed, it is assumed that wetland hydrology occurs for a sufficient period of the growing season to meet the wetland criteria, as described by Ecology ( 1997). ESA Page A-2 January 2014 Vantage Point Wetlands Study APPENDIX B: COMMON AND SCIENTIFIC NAMES OF PLANTS AND THEIR WETLAND INDICATOR STATUS ESA Appendix B January 2014 Vantage Point Wetlands Study PLANT SPECIES LIST FOR THE VANT AGE GLEN AND VISTA HEIGHTS PROJECT, IDENTIFIED ON AUGUST 28, 2007 COMMON NAME SCIENTIFIC NAME WETLAND INDICATOR STATUS* Trees bigleaf maple Acer macrophyllum FACU black cottonwood Populus trichocarpa (Popu/us FAC balsamifera ssp. trichocarpa) Douglas fir Pseudotsuga menziesii FACU* red alder A/nus rubra FAC western red cedar Thuja plicata FAC Shrubs common snowberry Symphoricarpos a/bus FACU dull Oregongrape Berberis nervosa NL English holly Jlex aquifolium NL Himalayan blackberry Rubus discolor FACU (Rubus armenicus) Indian plum (osoberry) Oemleria cerasifonnis FACU salal Gaultheria shallon FACU* Scot's broom Cytisus scoparius NL Scouter willow Salix scouleriana FAC tall Oregongrape Berberis aquifolium NL thimbleberry Rubus parv/florus var. parviflorus FAC- trailing blackberry Rubus ursinus FACU Herbs bull thistle Cirsium vulgare FACU bittersweet nightshade Solanum dulcamara FAC+ common St. John's wort Hypericum perforatum NL common tansy T anacetum vulgare NI English ivy Hedera helix NL field horsetail Equisetum arvense FAC herb Robert Geranium robertanium NL reed canarygrass Phalaris arnndinacea FACW soft rush Juncus effuses FACW stinging nettle Urtica dioica FAC+ sword fem Polystichum munitum FACU *Key to Wetland Indicator Status codes -Northwest Region (Source: USFWS, 1988, 1993): ESA OBL Obligate: species that almost always occur wetlands under natural conditions (est. probability >99%). FACW Facultative wetland: species that usually occur in wetlands (est. probability 67 to 99%), but are occasionally found in non-wetlands. Page B-1 January 20 14 ESA Vantage Point Wetlands Study FAC Facultative: Species that are equally likely to occur in wetlands or non-wetlands (est. probability 34 to 66%). FACU Facultative upland: species that usually occur in non-wetlands (est. probability 67 to 99%), but are occasionally found in wetlands. UPL Upland: species that almost always occur in non-wetlands under normal conditions (est. probability >99%). NL Not listed: species that are not listed by USFWS (1988, 1993) and are presumed to be upland species. NI No indicator: species for which insufficient information is available to determine status, or which were not evaluated by USFWS. + indicates a species that is more frequently found in wetlands indicates a species that is less frequently found in wetlands • identifies a tentative assignment based upon either limited information or conflicting reviews Page B-2 January 2014 Vantage Point Wetlands Study APPENDIX C: WETLAND DETERMINATION DATA FORMS AND WETLAND RATING FORM ESA Appendix C January 2014 ·- ' . .. DATAFORMl Routine Wetland Determination · (WA State Welland Deline~tion Mnnuafii~. 1.987 Com• Wetland Delineation Mannan Date: D~2.g:·D7 Proje.ctSite: Va.rriTJJ:J, Gile,e ,/Vl~~eJ~/<ls .. =--'. Applicant/Owner:_ .J<1~ toUJ\"D_j ~USI~ A-utV'ID'(d::j County: /<..-~ .. State:WA Investio•torfs): t1+ ,LT S/T/R: NW S?J:z..../T'.2-~ /R5 Do normal circumstances exist on 1he site? ~i Community ID: We..+~ol A-" Is 1he site significantly disturbed (atypical situation)"'I Yes o -Transect ID: We:,1-/a .. ls the area a potential problem area? Yes o Plot ID: DP .1- VEGETATION . . Dominant Plant Species Stratum. Perceot . Indicator Donrlµant Plant Species Stratum ·Percent Jndicator ·cover cover-.. -...----, . .. ________... A\,n .... ;;-lAr-. ~ T foo C _Fite__,, )R ' -. V-~c;i' t\..,..._..,Q, V: 6D( FkU· ./ ) ' fAGu Lio( ~-- .A. -" . . I \\ .• VV'\• T /5 ~~Q..Y'\V..."""-) I. ( ,._· -V f/t(..J--, ... Y.-. -V\...\--.:r •• --s ID . !=Ac. ?b\u~I"""-"" lAV\;~\;y\ ·ti-5 F~ s ID FAr/J c:. ' -a,. I . t-e,:c,~·.l,,;.,,,u3 . c;_ --. \1,.w, .\.,\ .... \ ,I A fi ... AGW (oD ( --I V • 17 i,.."--· •· o.rrn;._,11:, o. ~ · ·~ .• V F~c.. H /0 FAcw --:::;/ PhAlan·-l:i."'. -~1;-,..w ,.~ ~~\... •~: <,;.,•_::i:-~1A:,,°\. .S I S . FfaC.t- HrnROPlIYTIC VEGETATION INDICATORS: . . :. ... r . . . . . . ' .. ~· ,, 15% -· . % of dominants.OBL, FACW. & FAC: · · ' -. '• Cbeck all indicators ~ apply & explam below: - ... ·.: .Regional knowledge ofplill\t communities x Wetland Plant List (Natl or regional) X OTHER•·. . . ' · .. .. Physiological or reproductive_ adaptations Mmphological adaptations . - Te~bnical literature Wetland plant data base x· ' .. . . . . .. . . ' . . ,. . .. Hydrophytic vegetation present: ~ No Rationale.for Decision/Rematb: . Go-rri, r'IO('I+ ·"'< ~e ie\--fu.c\ ' ~rophjfiC.., r IS .. HYDROLOGY .. , .-. ~ Is it the growing season: No WeterMarks: Yes. (No'\ Sediment D=osits: Yes ,No .Based on: D::rre., . Drift Lines: Yes( ) Drainaw. Patterns: Yes "-101 Dept of inundation: -inches Oxidized Root (live ro@ Local Soil Survey: Yes No g Channels <12 in. Y~s o .. Depth to free water-in pit: inches FACNeu1ral: Ye~ Water-stained D....;th to s.aturated ~oil:" ... ·o inches Leaves: Yes~ Check all that apply & explllin. below: Other: Stream, lake or gage data: . Aerial photograp)is: Other: Wetland hydrology present? . (Yes ) No Rationale for decision/remarks: -. wate., pre<::.em-;n so', I w 8 ir,c. l,,q_s {co-.rl-inutd nq,,, "5 ol u ("\'::) dcr-1-o. col/<U:.fiix'l) .. . ., . .. , ·· .. ·~I/ ·\, r. ' Profile Description . : Depth·. Horizon Matrix color Mottle colors Mottle abundance Texture, Drawing of soil .l (inches)" (M1D1Sel1 (Munsell size & con1nlst · concretions, profile (match moist\ moist). ·-structure. etc. · descrlntion) 0-5 A /f)'(R Z-/ I --Q?,¥1~ I D" ,..;c . l'fi-1!<.~~ · 5-rz .. .8 <3\ I '+{lbY --. --. ·St\lr;fJ_;ia!j • . •. . . .. ,, .. • < ... .. • . · Hydric Soll Jndicafors: (Check all that apply) ' Hlstosol ... · concretions Histic Epipedon · · High. organic content in surface iayer of seildy soils ,, . Sulfidic Odor Organic streaking in sandy soils .. .' Aq\lic moistate regime Listed on Local E:ydric Soils List Reducing conditions Listed on National Hydric Soils List " ~ Gleyed.or low-chroma colora Other (explain in remarks) .. : • .. _-;:--'-... Hydric soils present'/ C:!_:V No. .. Rationale fur decision/remarks: LD#' .c/;.~ $ til~ ~I pre.~, . . . WeOand Determina'tion.(ciJcle) : ~ - , , Hydr?ph~c veg!:':3-_ti;~ present? , ( -~ · No .. . -• - " .. . Hydric soils present'/, _.· es No Is the sampling point w!tbin ~ w~and? @ No . Wetlandhvdrolo ,' ent'I ,. es .-No . . i·. .. , . .. . . Ra!tiO~l!llllll")!Jl:, • •1· ·--· ' "::· .. . 1\--[ i' 8 wci-/o._nd cri.-\·~c( CLre. pre~-01rophtfc-1e~+1on~ rvJ_rol~< aiic( -hL\cl..r\c.. -=1:ei IS, •. .. ' '·· _ :('iOTES: ; .• • .. . :,.' ~r of' .•. . -~·. •• . ,. •' -. . . . :~. -.'· . .;,. -.. '-· . ., ~ ...... ·.~t· ...... DATAFO~l Routine Wetland Determination · (WA State Wetland Delineation Manuiilo~ · 1987 Corns Wetland Delineation Manmill ProjectSite; Van+a~tl.._ ,IVistc.\~s.--~-"-Date: 08_, Z!r_·=D~/~------- Applicant/Owner. Ki rci Cou.. rrh) Housircr Au-#ormJ County: l<1M .. . . · :J ·.] ..J · · ..] State: VI/ A .J . . InvestiPntor(s): R \.-\-, ) :T · · . . srr!R:. 1\\11,/ 5 B2.. ITZ.3/fZt:=-i Do normal circumstances exist on the site? .. (Yes)· . No Community ID: \Aerlarvl A Is the site significantly disturbed (atypical situation)?_ "y6 jfij;) Transect ID: Upa rv( . . . Istheareaapotentialproblemarea? · Yes ® PlotID: f',,p? VEGETATION. Dominant Plnnt Species Stratum · PeTI:ellt . Indicator Domi!).ant Plant Species Stratum ·Percent .Indicator · -~Der . ;-A r , I Oo-10...-., a· r'Q,('h"'-:rGtrr,ii• S .,, ,.,.., .vA V T 7D .1 Zo ·-HYDROPHYTIC VEGETATION INDICATORS: .. %i>fdil~~-~L.FACW,&FAC: .83 ~~- Check ell indicators that apply & explain below: . , . . cover, Regional knowledge of plilQt communities )( Wetland Plant llit (Natl or regional) X OTHER., .. Physiological or reproductive adaptations _' __ Morphological adapmtions · Te\lhnical literature . Wetland plant data base x · .. Hydrophytic vegetation present: Yes l.::NgJ ' ·Ratlona!e.for·Decision/Remarks: \:a.wif ~ S01,. ,,f. &orri1~ o.x-e.. D.BL.., FACW 1 o.. FA-C... HYDROLOGY Is it the ~wing season; ~ No .Basedon: ~--' WaterMarks: Yes. 'd\ln Drift Lines: Yes ~Nii) Oxidized Root (live roots) Channels <12 in@ No Sediment Deuosits: Drain81!e Patterns: Local Soil Survey: -- : .. ri"'. Yes 'il<l.) Yes ~en Yes ,lfo .. Dept. of inundation; -inches Depth to free water-in pit: > I lo inches D~th to s_atur.ated ~ciil:" .. ';> / I inches FAC Neutral: Yes~ Water-stained Leaves: Yes~- Check all that apply & expllifu below: Stream, lake or gage data: _-__ Aerial photograpps: Other: Other: Wetland hydrology present? Yes ~ No J Rationale for decisionlremmks: -~ · no .=ia-+v-0..-fi11 .. .--i DC ·,nu rdbf,';h-, pres(...nt-o±-do:trt plc:St-.. ... ·.: ' . ' .. ..;, , ' ·-1· y_· . . . ·...., . '. ,: . ·,_ ,~ ,._ / son.,s _ . . . .._ . . .. . _ _ _ _ · _ . .. _· (.' _..- Map U~N~e Alde.~O?d arll.~Q,l lr."; -&Lrd~· . . Dnrinag~ Class !11:de.ra/-e/ :3. ~I ct.ro.\/"(2.d" (Series&Phase) ['OO.('() 'f.c,to"' /5 p$1r.enf:-· :·),' ··' · · _____ 1 ____ _ , ____ __.,_. ---~-l ---------Field--observation:s---.:onfinn---:-· .::. . 'taxonomy (subgrolip) En-nC:.. Duroc.hrep~ .. mappedtype7 -Yes(:E) Profile Description , : Depth·. Horizon Matrix color Mottle colors Mottle ablllldance Textnre, Drawing of soil Cinches)' {MllllSell {MllllSell size & contra.st · concretionsJ profile (match -nioist)" moist). .. structure, etc. · descrintion) D-!./-A _1DY~'*2 ---I oa..rn ~-'lb .·5 2 .$ Y-L/J.3 2.SY s/t.J. C,O ·rr, rr,fu l . -h N., \ ·, <"l"t" . Si ltz.\ e,la..5 · ! .. .. ,, -·· " ' .. .- · Hydrlc Soil Indicators: (Check all that apply) .. Histosol · · -Cmicietions . _ . IDstic Epipedon · · IDgh organic conte:nt in surface layer of sandy soils -· . Sulfidic Odor Organic stremcing in sandy soils .. ' Aq\llc moistate regime Listed on Local llydric Soils List - Reducing conditions Listed on National Hydric Soils List .. G!eyed or low-chroma colors Other (explain in rem~) ' ' Hydric soils present? Yes ~ ,. Rationale for decision/remmks: 1Sv',-\ ·&oe:: rot-~!() ~i1.z.rr+-~ctt'tC.: kd1 1 co.~~ .. Wettand Determinatlon_(cip:le} C .. --.. ·,·. -· ' '© - , . Hydrophytic veg~tation present? Yes .. -- y~-}:iydric soils preseni'ri",-' Yes .. e ls the sampling point w!thin ~ wetland? . Wetlandhydrologypresent'l . Yes Rl!tlonal'!IRemarkll:---. ,. ·- ; "::· --!ict'1·-wrl-f dc-J .' cri:k."-o.. · not •' 3 rraT. ,_ .-. : ••,:',• ' ;:;· .- " .~OTES: ... . .. ; , bPZ. ~ti~J~ w«.. wLA · ... :,, ,iv· .•. •• ,. ,' ~ ... . ~· ·:,· .. • . . ,_ .;; • . .· ... .., ... . . •• , ....... ~' , .. ,I. • .. ··- ·' _, -1~·-'' . {. ~-.· . ~-', l' .. ) . '. •'.,t• 1; . . . i·. :. ;'I·. ... Wetland n"!l'e or number /;..\LA . WETLAND RATING FORM-WESTERN WASIDNGTON V e,s1on 2 -Updated July 2006 to increase accuracy and reproducibility among users . Name of wetland (if known): I >-le.\\ ,,,,,A Rated by L :n.,,"".e . A: -,l,.v-11 -;;"' ~\,,,::-\.~ Dateofsitevisit: 8{-z'blD7 \I ,~'nC E:Jl.c'-"' . . . ' Trained by Ecology?· YesX: No_··-Date of training Sp.,; '(f O(p SEC: TWNSHP: RNGE: Is S/T/R in Appendix D? Yes_._· No Map of wetland unit: Figure_ Estimated size __ _ SUMMARY OF RATING Category based on FUNCTIONS provided by wetland 1 II m IVX' -----,-. Category I = Score >=70 Category Il = Score 51-69 Category ill= Score 30-50 Category IV= Score< 30 Score for Water Quality Functions Score for Hydrologfo Functions Score for Habitat Functions TOTAL score for Functions Category based on SPECIAL CHARACTERISTICS of wetland . I_ II_· _. Does not A.pply_X Final Category (choose the "highest" ca~ory from above) •• , ., . !- Summary of basie information about the wetland unit . Estnarine . ·NamralHerita eWetland Bo Mature Forest Old Growth Forest Coastal La oon Interdunal None of the above Flats Freshwater Tidal Check if unit has multiple HGM classes resent 1--::L. Wetland Rating Form-western Washington version2 1 August 2004 . Wetland name. or number-¥ Does the wetland unit being.rated meet any ofthe criteria below? If you answer YES to any of the questions below you will need to protect the wetland ~ccording to the regulations regarding the special characteristics found in the wetland. lf.~~1=J.~~I~~~~~\~-JilirJ~i1~iJ;~~;:~ll'~j ___ \!d,----=~ ==~2i---------.......---•----·~-----· .t,;;.-..w ___ =.;..:.........¥, L-= SPl. Has the wetland unit been documented as a habitat for any Federally listed X Threatened or Endangered animal or plant species (TIE species)? For the purposes of this rating system, "documented" means the wetland is on the aoorooriate state or federal database. SP2. Has the wetland unit been documented as habitat for any State listed Threatened or Endangered animal species? \ ./ .• For the pwposes of this rating system, "documented" means the wetland is on. the appropriate state database. Note:. Wetlands with State listed plm:rt species are /~ categorized as Cate2orv I Natural Heritage Wetlands (see o. 19 of data form). SP3. Does the wetland unit contain individuals of Priority species listed by the X WDFW for 'the state? SP4. Does the wetland unit have ·a local significance in addition to its functions? )( For example, the wetland has been identified in the Shoreline Master . Pro~, the Critical Areas Ordinance, or in a local management plan as having special significance. ( To complete the next part of the data sheet y;u will need to determine ihe Hydrogeomorphic Class of the wetland being rated. The hydrbgeomo:rphic classification groups wetlands into those that function in similar ways. This simplifies the.questions needed to answer how well the wetland functions. The Hydrogeomorphic Class of a wetland can be determined using the key below. See p. 24 for more detailed instructions on classifying wetlands. Wetland Rating Form -western W asbington ,.;ersion 2 2 Angust2004 Wetland name ornumber 4 -=======_,c .... Jassifieation.o£Wetland IInitsJR.Western Washingt.,n11n=· ====-~--~ 1. ~ water levels in the entire unit usually controlled by tides (i.e. ·except during floods)? ~ go to 2 . YES-the wetland class is Tidal Fringe · · .•... If yes, is the salinity of the water during periods of annual low flow below 0.5 ppt (parts per thousand)? YES -Freshwater Tidal Fringe NO-: Saltwater ·Tidal Fringe (Estuarine) If ydur wetland ca~. be classified as a Freshwater Tidal Fringe use the forms for Riverine wetlands. ]fit is Saltwater Tidal Fringe it is ra.ted as. an Estuarine wetland. Wetlands that were called estuarine in the first and second. editions of the rating system are cal)ed Salt Water Tidal Fringe in the Hydrogeomorphic Classification. Estuarine wetlands were categorized separately in the earlier editions; and this separation is being kept in this revision. To maintain consistency between editions, the term "Estuarine" wetland is kept Please note, however, that the characteristics that define Category I and II estuarine wetlands have changed (seep. ). . 2. The !llltire wetland unit is flat and precipitation is the only source (>90%) of water to it adwater and surface water runoff are NOT sources of water to the unit · . go to 3 YES.-'-The wetland class is Flatil · your wetland can be classified as a "Flats" wetland, use the form for Depressional . wetlands..-_ · · 3. D9~s the entire wetland unit meet both ofthe following criteria? . · The vegetated part of the wetland is on the shores ofa body of permanent open water -(without any vegetation on the surface) at least 20 acres (8 ha) in size; _At least 30% ofth.e open water area is deeper than 6.6 ft (2m)? . . . go to 4 YES -The wetland class is Lake-fringe (Lacnstrine Fringe);; ... 4.. s the entire wetland unit meet all of the following criteria? ,. . ·,;;: · · . 'I The wetland is on a slope (slape can be very gradual), . · ·;, "L . The water flows through the wetland in one direction ( unidirectional) and usually r-comes from seeps. It may flow subsurface, as sheetflow, or in a swale without distinct banks. . -P The water leaves the wetlaod without ~eing impounded?. . ' . NOTE: Swface water does not pond m these type of wetlands except occasionally m very small and shallow depressions or behind hummocks (depressions are usually <3.ft d~~t and less than I foot deep). NO· go·to 5 U The wetland class. is Slope WetlandRatingForm-westem Washington version 2 3 August2004 Wetland name _or n~mber ~ 5. Does the entire wetland unit in~t all oftli~ fo!]owing criteria? · .. __ The unit is in a valley, or stream channel, where it gets inundated by overbank flooding from that stream or river __ The overbank flooding occurs at least once evecy two years. NOTE: The riverine unit can contain depressions that are filled with water when the river is _eia.,t flooding. · · ~o 'to 6 YES -The wetland class. is Riverine . 6. Is the entire wetland unit in a topographic depression in which water ponds, or is saturated to the surface, at some time during the year. This means that any outlet, if present, is higher than the · · j,iter:iJ of the wetland. · '-NO go to 7 YES-The wetland class is Depressional ·7. Is the entire wetland unit located in a very flat area with no obviollll depression and no overbank flooding. The 'unit does not pond surface water more than a few inches. The unit seems to be maintained by high groundwater in the area. The wetland may be ditched, but has no obvious ?~al-o_rtlet . ~o to 8 YES -The wetland class is Depresslonal . 8. Your wetland unit seems to lie difficult to classify and probably contains several di:fferentHGM clases. For example, seeps at the base of a slope may grade into a riverine floodplain, or a small stream within a depressional wetland has a zone of flooding along its sides. GO BACK AND IDENTIFY WIIlCH OF THE HYDROLOGIC REGIMES DESCRIBED IN QUESTIONS 1-7 · APPLY TO DIFFERENT AREAS IN THE UNIT (make a rough sketch to help you decide). Use the following table to identify the appropriate class to use for the rating system if you have several HGM classes present within your wetland. NO'IE: Use this table only if the class that is recommended in the second column represents 10% or more of the total area of the wetland unit being rated. If the area of the class listed in column 2 is less than 10% ofthe unit; classify the wetland using the class that represents more than 90% of the total area Depressional De ressional Treat as ESTUARINE under wetlands with special characteristics If you are unable still to determine which of the above criteria apply to your wetland, or if you have more than 2 HGM classes within a wetland boundary, classify the wetland as Depressional for the rating. Wetland Rating Form-westemWesbington version2 4 August2004 W ctland name or number ~ s s s S 1. Does the wetland unit have the potential to improve water quality? S 1.1 Characteristics of average slope of unit: Slope isl% or less (a 1% slope has a lfoot vertical drop in elevation for every 100ft . horizontal distance) " · points = 3 Slope is 1 % -2% · points = 2 · Slope is 2% -5~: • .;{.J'\ points ~' Slope is greater =e.,; . poin~ S 12 The soil 2 inch.es below the surface (or duff layer) is clay or organic (use NRCS definitions) · .YES. 3 o· NO= 0 oints S 1.3 Charactenstics of the vegetation in the wetland that trap.sediments and pollutants: Choose the points appropriate for the description that best fits the vegetation in the wetland. Dense vegetation means you have trouble seeing the soil surface (> 75% cover), and uncut means not grazed or mowed and plants are higher than 6 inches. Dense, uncut, herbaceous vegetation > 90% of the wetland area points = 6 Dense, uncut, herbaceous vegetation > 1/2 of area · points = 3 .h'I . Dense, woody, vegetation> Y, of area . points C2._J Dense, uncut, herbaceous vegetation> J/4 of area points.= 1 . . Does not meet any of the criteria above for ve etation oints = ·o 0 2.-. , ------------'-'·~,.ll!ffl00.1i1,,,!l"",""'""1il1"'."""" _J_, J! !Lile:>.,, oL ij .... ,_ ----I S Total for S 1 Add the J1oints in the boxes above I ~ ~;_,1-.,... .............................. _______________________ -1, ___ _ S · s.:2. Does the wetland unit have the opportunity to improve water quality? (see p.~7) s Answer YES if you know or believe there are pollutants in groundwater or surface water . . coming into the wetland that would otherwise reduce water quality in streams, l!lkes or groundwater downgradient from the wetland. Note which of the following conditions provide the sources of pollutants. A unit may have pollutants coming.from several sources, but any single source would qualify as opportunity. · · . =.Grazinginthewetlandor.within 150ft. -Untreated stormwater discharges to wetland -Tilled fields, logging, or orchards within 150 feet of wetland -Residential, urban areas, or golf courses ere within 150 ft upslope of wetland , . -Other -. YES multiplieris 2 NO multiplier ls_l __ ) TOTAL -Water Quality Functions Multiply the score from Sl by S2 Add score to table on , 1 Comments WetlandRatingFrum-w"51em Washington version2 11 August2004 multiplier \ 5 Wetland name or number I\-- s s S 3. Does the wetland unit have the potential to reduce flooding and stream erosion? S 3.1 Characteristics of vegetation that reduce the velocity of surface flows during storms. Choose ihe points approprirlle for the description that best fit conditions in the weiland (stems of plants should be thick enough (usually> l/8in), or dense enough,. to remain erect during.surface flows) · Dense, uncut. rigid vegetation covers > 90% of the area of the wetland. Dense, uncut. rigid vegetation> 1/2 area of wetland · · Dense, uncut, rigid vegetation> 1/4 area More than 1/4 of area is grazed, mowed, tilled or vegetation is .. _ ........ notri · d __ ......... ------.. ----· . ··-....... _ ..... -·---··-·-......... --·-·--__ · ___ ,.. . ........ ints. = .0 .. S 3.2 Characteristics of slope wetland that holds back small a.mounts of flood flows: The slope wetland has small surface depressions that can retah! water over at least 3 0 10% of its area. YES points= 2 c,- NO ointsTO f----------------~---~~--t=~~-'""c'.......--~----. Add the points in the boo;es above I .3 I s 1--+--..-------------------------------..... ----s S 4; Does the wetland have the opportunity to reduce flooding and erosion? seep. 70) s Is the wetland in a landscape position where the reduction in water velocity it provides helps protect downstream property and a,quatic resources from flooding or excessive and/or erosive flows? Note which oftlie following conditions. apply. · -· Wetland has surface runoff that drains to a river or stream that has flooding · problems . · · . · · ../. Other Ww-Y v:,, $r:o"l<A6 vi,.._,\/\ d i=lc""1,t.S \-o ~vv,......... {Answer NO if the major s'ource ofwmer is cimtrol/ed by a reservoir (e.g. wetland is a seep that is on the cl, side of a dam) 'YES multi lier i 2 NO multi lier is 1 Comments TOTAL -Hydrologie Funei:ions Multiply the score from S 3 by S 4 Add score to table on p.1 ·-=-=-~--···-· ·-,--=-===·-=·-'=·-=-==------.,= ..... ·-· ..... ----,,-··· ·· .. ·----· Wetland Rating Form-western Washington version 2 12 August 2004_ · multiplier 2- Wet]and name or number k_ ' H 1. Does the wetland unit have the potential to provide hab.itat for many species? H 1.1 Vegetation structure (seep. 72) · f,Hi!i~~ Check the types of vegetation classes present (as'defined by Cowordin)-Size threshold for each class is ~ acre or more than 10% of the area if wzitis smaller than 2.5 acres. __ Aquatic bed . . __ Emergent plants __ · Scrub/shrub (areas where shrubs have >30% cover) .2£...forested {areas where trees have >30% cover) jJJl,.e wzit has a forested class check if: · · . . · ,,L:-The forest¢ class has 3 out ofS strata (canopy, sub-canopy, shrubs, herbaceous, moss/ground-cover) that each cover 20% within the forested polygon . · . . · Add the number of vegetation structur,es that qualify. If you haye: · · 4 structures or more · points = 4 [~i.Rfof~@'.il:si\tlo~Jw!i 3 structures _points.:c_:2 ' Cfsiructures _ _:-__ .~points =-1 ., I structure oints = 0 H 12. Hydroperlods (seep. 73) !i!o!,i~ CJ,eck the types of water regimes (hydroperiods) present within the wetland. Thri water r11~me has to cover more than 10% of the wetland or ~ acre to count. (see text for . ·., d~ptions ofhydroperiods) ~~t ·, . · __ . _Permanently flooded or inundated / J 4 or more types present points = 3 __ Seasonally flooded or inundated . 3 types present points.= 2 _· _Occasionallyfloodedorinundated( ') · · 2typespresent ,po~ . ___£ Saturated only ' 1 type present points = ___ Permanently flowing stream or river in, or adjacent to, the wetland · · · . ..:':__ Seasonally flowing stream in, or adjacent to, the wetland · __ Lake-ftingii"wetland = 2 points . _Freshwater tidal wetland= 2 points ~·--~ H 1.3. Richness of Plant Species (seep. 75) . . Count the number of plant species in tlie wetland that cover at least 1.0 ft' .. (different pt1fc1~ .. , . of the same species can be combined to meet the size threshold) . · . . --.. . . ·, .• : tou ao niiifiiive 10 rnim~ ·1iiii species~--.. --------· · · · · · · · · · · · · ··· · · · · Do not include Eurasian Mi/foil, reed canarygrass, purple loosestrife, Canadian Thistle If you counted: > 19 species points = 2 List species below if you want to: 5 -19 species points ff) < S species points = O \ Wetland RJ!ting Form-westeJll Washington version 2 13 Total for page j August2D04 ,-.. Wetland name or number A .· H 1.4. Interspersion of habitats (seep. 76) Jg~ Decide from the diagrams below whether interspersion between Co war din vegetation classes ( descn1md in H I . I), or th.e classes and unvegetated areas ( can include open water or mudflats) is high, medium, low, or none. · · Non{,,, 0 points ,. ·------Moderate = 2 points ~ [ riparian braided channels] High ~ 3 points NOTE: If you have four or more classes orthr~ ve elation classes and open water the ratin is alwa s "hi ". tm a · . , • a H ·1:5. Special Habitat Features: (seep, 77) Check the habitat features that are present in the wetland. The nwnber of checb Is the · number of points you put into the next column. __ Liµ-ge, downed, woody debris within the wetland (>4ili. diameter and 6 ft long). __ Standing snags (diameter at the bottom> 4 inches) in the wetland __ Undercut banks·~ present for at least 6,6 ft (2m) and/or overhanging vegetation extends at· least 3.3 ft (Im) over a stream (or ditch) in, or· contiguous with the unit, for at least 33 ft (10m) __ Stable steep banks of fine material that might be used by beaver or muskrat for denning (>30degree slope) OR signs of recent beaver activity are present (cut shrubs or trees that have not yet turned grey/brown) __ At least% acre. of thin-stemmed persistent vegetation or woody branches are present in areas .thatare permanently or seasonally inundated.(structuresfor egg-laying by amphibians) _. _Inyasive plants cover less than 25~ oflhe we~and area in each stratum of plants : I NOTE: The 20% stated in early printingj ~/the man.ual on page 78 is an error. {!) ~------------..:..:;....._.=_..:_ ____ _.:;,-=.. _________ -1,.. ___ _ H 1. TOTAL Score -potential for providing habitat I ~ . I L-------------'A~d='d:..:t::.:;he:..:s:::c:::!or:c::e::..s =om=H:.:ol.::,.1;<...=:H:::.1·:.::2'-', H=l-:::,3,~H=l'..C.4.!!.,..e;He.:1.:.:.5:.....Ji...:. ___ J Comments Wetland Rating Form-western Washington version.:Z 14 August2004 )I Wetland name ornumber -A- H 2. Does the wetland unit have the opportunity to provide ba_bitat for many species? H 2.1 Buffers (seep, 80) Choose the description thot best represents condition of buffer of wetland unit. The highest scoring criterion thot applies to the wetland is to be used in the rating. See text for definition of 0 undisturbed. u . -100 m (330ft) of relatively undisturbed vegetated areas, rocky areas, or open water >95% of circumference. No structures are within the undisturbed part ofbuffer, (relatively undisturbed also means no-grazing, no landscaping, no daily human use) Po in Ill "' S -100 m (330 ft) ofrelatively Jindisturbed vegetated areas, rocky areas, or open water > 50% circumference. · Poinlll = 4 .-50 m (170ft) of relatively undisturbed · vegetated areas, rocky areas, or open water >95% · circumference. Polnlll = 4 -100 m (330ft) of relatively undisturbed vegetated areas, rocky areas, or open water> 25% circumference, . Poinlll = 3· -· SO m (170ft) of relatively undisturbed vegetated areas, rocky areas,. or open water for > 50% circumference. · Poinlll"' 3. H buffer does not meet any or the criteria above · -No paved areas (except paved trails) or buildings within 25 m (80ft) of wetland> 95% circumference. Light to moderate grazing, or lawns are OK. · Points = 2 ;ic. No paved areas or buildings within 50m of wetland for >50% circumference. ,..;-.---., · · .. ,Light to moderate grazing, or lawns are OK. Poinll!f!_} -· ','.Heavy grazing in buffer. · · Points = 1 · ; -!Vegetated buffers are <2m wide (6.6ft) for more' than 95% of the_ ·circumference (e.g. filled Jields, paving, basalt bedrock extend to edge of wetlmid · Po in Ill = 0. -Buffer does not meet any of the criteria above. · Points= 1 '2.__ ml H 2.2 :Corridors and Connections (seep. Bl) H'2.2. l Is the wetland pert of a relatively _unilisfurbed and linbroken vegetated corridor (!!lther riparian or upland) that is at least 150 ft wide, has at least 30% cover of shrubs, forest -· or native undisturbed prairie, that· connects to estuaries, other wetlands or undisturbed uplands that are at least 250 acres in s~'t (dams in riparian corridors, heavily used gravel roads,pavedroads, are considered breal,s in the corridor)-. , .:,.,,. . YES=4poinl5 (gotoH2.3) ~gotoH2.2.2 . '·"'is.. H 2.2.2 Is the wetland part of a relativeiy 1,IDdisturbed and unbroken vegetated corridor,,· . . ( eitfier npiiiiiii iiriijiliiiio}tliafis' iifleiisfSlllt wide, 'Jias if least 30% coverofshrulis-cir •. forest, and .connects to estuaries, other wetlands·or undisturbed uplands that are at least 25 · acres in size? OR a LaJt.frlnge wetland, if i.t ·does. not have an undisturbed corridor as in the question above? YES = 2 points (go tp H 2.3) H 2.2.3 Is the wi:tlend: within 5 mi (8km) of a brackish or salt water estuary OR within 3 mi of a large field or pasture (>40 acres) OR within l mi of a lake greater than 20 acres? YES·=l oint ,..---, NQ=;O oinb! · C) Total for page C Wetland Roting Fonn -wostem W asbington version 2 15 August2004 Wetland name ornumber _k H 2.3 Near or adjacent t!l <lther priority habitats listed by WDFW (seep. 82) Which of the following priority habitats are within 330ft {100m) of the wetland unit? NOTE: the connections do not have to be relattvely Wldisturbed. These are DFW definitions. Check with your local DFW biologist if there are any questions. __ Riparian: The area adjacent to aquatic systems with flowing water that contains elements of botll ,i.qµatip l\lld terr~~al ecosystems w~ch mutually iilfluence each other. __ Aspen Slands:"Pure or '.lllixed stands of aspen greater than 0.8 ha (2 acres). _Cllflll: Greaterthao 7.6 m (25 ft) high and occurring below 5000 ft. · _Old-growth forests: (Old-growth west of Cascade crest) Stands of at least2 tree species, forming a multi-layered canopy with occasional small openings; with at least 20 trees/ha (8 trees/acre)> 81 cm (32 in) dbh or> 200 years ofage. __ Mature forests:· Stands with average diameters exceeding 53 cm (21 in) dbh; crown cover may be less that 100%; crown cover may be less·that.I 00%; decay, decadence, numbers of snags, and quantity of large downed material is generally less than that found in old- growth; 80 -200 years old.west of the Cascade crest.· __ PJ:all'!"!ii . :R.-!'!\l~_eJy_ 1,lll.~1:>.t;~ ~ .(Ill! .~!i!~_by ~t:>!'1\';!anc.e of native plmrts) wlle_re . grasses and/or forbs form the natural climax plant community •. --'-Talns: Homogenous areas ofrock rubble ranging in average size 0.15 -2.0 m (05 -6.5 ft), composed ofbasalt, andesite, and/or sedimentary rock, including riprap slides and mine tailings. May be associated with cli:ffi;. __ Caves: A naturally occurring cavity, recess, void, or system of interconnected passages _ Oregon white Oak: · Woodlands Stands of pure oak or oak/conifer associations where canopy coverage of the oak component of the stand is 25%. __ Urban Natural Open Space: A priority species resides within or is adjacent to the open space and uses it for breeding and/or regular feeding; and/or the open space functions as a corridor connepting other priority habitats, especially those that would otherwise be • isolated; ,!II!d/or the open space is an isolated remnant of natural habitat larger than 4 ha (10 acres) and is surrounded by urban development __ Estuary/Estuary-like: Deepwater tidal habitats.and adjacent tidal wetlands, usually semi- enclosed by Ian\! but-with open, partly obstructed or sporadic access to the open ocean, and in which ocean Waler is at least occasionally diluted by freshwater runoff from the land. The salinity may be periodically increased aboye that of the open ocean by evaporation. Along some low-energy.coastlines there is appreciable dilution of sea water. Estuarine habitat extends upstream and landward to where ocean-derived salts measure less than 0.5ppt·duriog the period of average armual low flow. Includes both estuaries and lagoons. __ Marine/Estuarine Sh!)Jellnes: Shorelines include the intertidal and subtidal zones of beaches, and may also include 1:heblil:kshore and adjacent components ofthe terrestrial landscape (e.g.; cliffs; snags;mature trees, dunes, meadows) that are important to shoreline associated fish and· wildlife and that contnoute to shoreline function ( e.g., sand/rock/log recruitment, nutrient contribution, erosion control). If wetland has 3 or more priority habita1s = 4 points If wetland has 2 priority habfuits = 3 poinlll . a Ifwetlandhas.lpriorityhabitat=lpolnt • Nohabi~-Op ints . Note: All vegetated wetlands are by definition a priority habitat but t included in this list. Nearby wetlands are addressed in auestion H 2.4) 0 .... "--.. -:.-• .... •.,.~~--=--· --~-"'C..-~-'==-·-"'------------·----"----'--~-------· ·-·--·----·,,-r.,-e.,_ .... -·--··-·------... ·.·------.. ··-.. ·--·-·--·-·····--···-----·-.. =-,,-•. -..•.. - Wetland Rating Form-western Washington version 2 16 Angust2004 Wetland name or number A- _ J,t2,i Wetland Landscape ~s_e the ~.np1iPJLaithe landscqp,LJ!__rp.Wld the -wetlandjhrJL............ bestfits) (seep. 84) · · · There are at least 3 other wetlands within V. mile, and the connections between them are relatively undisturbed (light grazing between wetlands OK, as·is lake shore with some boating, but connections should NOT be bisected by paveq roads, fill, fields, or other development. · · · points = 5 The wetland is Lake-fringe on a lake with little disturbance and there are 3 other lake-fringe wetlands within V. mile __ ,. _ points = 5 There are at least 3 othe!'wetlands withio V. mile, BUT the connections between them are disturbed · · points = 3 The wetland is Lake-fringe on a lake with disturbance and there are 3 other lake-fringe wetland withio V. mile · · points = 3 There is at least I wetland within V. mile. points = 2 -··----··· ... -----~, .. .__ _ _.._ ~ .- There are no wetlands within V. mile. ., pointsc!_J . Q r-.,..---. Hl. TOTAL S;ohre-oppozimtyH2_ fo 1 rH2provi 2 'dinH' ghabitat_ 1 2 1 !--------...:.... ______ . _:.,A::,:di,:.u.:,t ,::e_,,s.:::coe!r_,,es"-.L!..:comc:.:..=.=· o.,•===· :,_, =2,:,3:,., H2=·:..!4-!--"""-_. TOTAL forH 1 from page 14 <l_ 1------------'----------1-::r.: __ _ Total Score for Habitat FunctiQns -add the points for H l, H 2 and record the result on -n.l r.o •:,.~- i, ·: -fir ., ... ~ ... 0·0·':f,;: . :.~. ~-- Wetland Rating Fonn-westmn Washington version 2 17 ~----:·· August2004 Wetland nome or number_/±___ CATEGORIZATION BASED. ON SPECIAL CHARACTERISTICS Please determine if the wetland meets the attributes described below and circle the appropriate answers and Category. SC 1.0 Estuarine wetlands (seep. 86) Does the wetland unit meet the following criteria for Estuarine wetlands? -The dominant water regime is tidal, -Vegetated, and _ ·-. With a salinity greater than 0.5 ppt . YEEf= Go to sc LI . SC 1; 1 Is the wetland unit within a National Wildlife Refuge, National Parle, National Estuary Reserve, Natural Area Preserve, State Park or Educational, Environmental, or Scientific Reserve desi!ll!ated under WAC 332-30-151? YES=Cate o I . ~pSC.1.2 . · SC 1.2 Is the w~tland unit at least 1 acre in si~ets at least two of the .following three coni:litions? · YES = Category I NO = Category II -The wetland is relatively undisturbed (has no diking, ditching, filling, cultivation, grazing, and has Jess than 10% cover of non-native plant species. If the non~native Spartina spp. are the only _species that cover more than 10% of the wetland, . then the wetland should be given a dual rating (I/II). The area of Spartina would be rated a Category II while the relatively undisturbed upper marsh with native species would be a -' . Category I. Do not, however, exclude the area of Spartina in determining the size threshold of 1 acre .. -:;-: At least % of the landward ec;lge of the wetlanq has a 100 ft buffer of · · , shrub, forest, or un-grazed or un-mowed grassland. -The·wetland has at least 2 of the following features: tidal channels, depressions with open water, or contiguous freshwater wetlands. Wetland Rating Form~ wesll:m W ashirigton 18 August2004 version2 Cat.I Cat.I Cat.Il Dual rating I/II Wetland name or number .A_ ~-------------'---~---------------~---~-c•--··-········ SC 2.0 Natural Heritage Wetlands (seep. 87) Natural Heritage wetlands have been identified by the Washington Natural Heritage Program/DNR as either high quality undisturbed wetlands or wetlands that support state Threatened, Endangered, or Sensitive plant species. SC 2.1 Is the wetland unit being rated in a Section/Township/Range that contains a Natural Heritage wetland? (this question is used to screen out most sites before you need to coniact WNHPIDNR) · .S/T/R information from Appendix_D _ or accessed from WNHPIDNR web site _·_ YES __ -contact WNHP/DNR (seep. 79} and goto SC 2.2 NO V ( '- SC 2.2 Has DNR identified the wetland as a high quality undisturbed wetland or as or as a site with state threatened or endangered plant species? · · · YES= Category I NO X not a Heritage Wetland . -----. . SC 3.0 Bogs (seep. 87) . Does the wetland unit (or any part of the unit} meet both the criteria for soils and vegetation in bogs? Use the key below to identify if the wetland is a bog. If you answer yes you will still need to rate the wetland based on itsftmctions. :1.-Does the unit have organic soil horizons (i.e. layers of organic soil}, either ·:·.-:· peats or mucks, that co~pose 16 inches or more of the first 32 inches qfthe · :~· soil profile?.(See Appendix.B for afield key to identify organic soils)? Yes - :: go to Q. 3 · ('No) go to Q. 2 · · . °:Q. Does the unit have organic ~ons;either peats or ~ucks that are Jess than 16 inches deep over bedrock, or an impermeible hardpan such as clay or· volcanic ash, or that are. flollling on a lake or pon9,? Yes -go to Q. 3 ·06]s not a, bog for purpose of rating 3. Does the unit have more than 70% cover of mosses at ground level, AND · other plants, if present, consist of the "bog" species listed in Table 3 as a ,. significant component of the vegetation (more than 30% of the total shrub. ' and herbaceous cover consists'~f SJ>ecie.~ in Tabl~!)~ · · · · , Yes-Is a bog for purpose of rating "(.No. goto Q. 4 NOIB: If you are uncertain about the ~ent o£.m6sses in the understory you may substitute that criterion by measuring the pH of the water that seeps into a hole dug at least 16" deep. If the pH is less than 5.0 and the ''bog" plant species in Table 3 are present, the wetland is a bog. 1. Is the unit forested(> 30% cover) with sitka spruce, subalpine fir, western red cedar, western hemlock, lodgepole pine, quaking aspen, Englemann's spruce, or western white pine, WITH any of the species (or combination of species} on the bog species plant list in Table 3 as a significant component of the ground cover(> 30% coverage o-r;e total shrub/herbaceous cover)? 2. YES = Category I No Is not a bog for purpose ofrating Wetland Rating Form-western Washington ·version2 /' 19 August 2004 · Cat.I ' -·· Cat.I Wetlondnameornumber A SC 4.0 Forested Wetlands (seep. 90) Does the wetland unit have at least I acre of forest that meet one of these criteria for the Department of Fish and Wildlife's forests as priority habitats? If you answer yes you will still need to rate the wetland based on its functions. · -Old-growth forests: (west of Cascade crest) Stands of at least two tree six:cies; forming a multi-layered canopy with occasional small openings; with at.least 8 trees/acre (20 trees/hectare) that are at least 200 years of age OR have a diameter at breast height (dbh) of32 inches (81 cm) or more. NOIB: The criterion for dbh is based on measurements for upland forests. Two-hundred year old trees in wetlands will often have a smaller dbh ~ecause their growth rates are often slower. The'DFW criterion is and "OR" so old-growth forests do not necessarily have to have trees· of this diameter .. . -Ma~-forests:{wi:st"ofiiie Cascade. Crest) St.ands where the fargesttrees are 80 ~ 200 years old OR have average diameters (dbh) exceeding 2i inches (53cm); crown cover may be less that 100%; decay, decadence, numbers of snags, and quantity oflarge downed material is generally less than that found in old-growth. YES = Category I NO -J not a forested wetland with special characteristics Cat. 1 ·. I SC 5.0 Wetlands In· Coasful Lagooful (see.p. 91) Does the wetland meet all of the following criteria of a wetland in a coiistal lagoon? -Toe wetland lies in a depression adjacent to marine waters that is wholly or partially separated from marine waters by sandbanks, gravel banks, shingle, or, less frequently, rocks -The lagoon in which the wetland is located contains surface, water that is saline or brackish (> 0 .S ppt) during most of the year in at least a portion of the lagoon (needs to be measured near the bottom) YES= Go to S.C 5.1 NO __xnot a wetland in a coastal lagoon -· / ' SC 5 .1 Dci~ the wetland meets all of the following three conditions? -The wetland is relatively undistrirbed (has no diking, ditching,' filling, cultivation, grazing), and has !es~ than 20% cover of invasive plant species (see list of invasive species on p.14). · . -At least% of the landward edge of the wetland has a 100 ft buffer of shrub, forest,· or un-grazed or un-mowed grassland. -The wetland is larger than 1/10' acre. (4350 _square feet) • YES = Category I. NO = Category TI . WeOondRating Fonn-wostem Washington 20 August2004 version 2 · Cat.I Cat.ll . Wetlandnameornwnber k ----···-,··· ··========="'================--·=·-·-=-==-""·-"']··· ----,---~ -,· .. , • SC 6.0 Interdunal Wetlands (seep. 93) -Is the wetland unit west of the 1889 line (also called the Western Boundary of Upland Ownership or WBUO)? · YES -go to SC 6.1 . NO Ynot an interdunal wetland for rating If you answer yes you will still nee,fto ride the wethmd based on its Junctions. · In practical terms that means the following geographic ru:eas: . • Long Beach Peninsula-lands west of SR 103 • Grayland-Westport-landswestofSR 105 • Ocean Shores-Copalis-lands west of SR 115 and SR 109 SC 6.1 Is the wetland one acre or larger, or is it in a mosaic of wetlands that is once acre or larger? . YES= Category II NO -go to SC 6.2 SC 6.:2' Is the unit between O .1 and 1 acre, or is it in a mosaic of wetlands that is between 0.1 and 1 acre? YES = Category III r~~-~·-n-~ -------------,.---------,,,----=-·= --,~--~---=-,--~ -')",'~ "1 1 '·:.@j}r,._:rri,~'(il. IT:Glb,(i1fo\\"N'.J©F ;:iwiiftJIJ'.QJltill.!@B:\11'.fili'(=-"::\ _ "--.. · · , ' -.: -,.; ~ .. · · .-- 1 , ~:i~~~I~~tffil ·;1;1_~~7?~~ 1 : lr@gf?~f{t~)~/i?lit1J4J~!t~}(!.t<l'~~~{"q?1llJ!~;!/}t~)~;if}~~~@J!i~,~~f_coJ,iltra~'. '. ~;~~~~iw:ii.~~;~~ri 5~~~~ f~~~ ~~©f~l~'.:~;~~~~;~~;#::\, • ~~ :=·-:~.", l Cat. II Cat.ID Wetland Rating Form-western Washington version 2 21 August2004