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HomeMy WebLinkAboutRS_Technical_Memorandum_220119_v2Wetland & Aquatic Sciences Wildlife Ecology Landscape Architecture 2111 N. Northgate Way, Ste 219 Seattle, WA 98133 206-525-8122 raedeke.com Associates, Inc. Raedeke TECHNICAL MEMORANDUM November 30, 2021 revised January 19, 2022 To: Mr. Sean Vanos Seattle Seahawks 12 Seahawks Way Renton, WA. 98056 From: Kolten T. Kosters, M.S., PWS Wetland Scientist Raedeke Associates, Inc. Shraddha Sawant Landscape Designer Raedeke Associates, Inc. RE: VMAC Field Resurfacing – Shoreline Mitigation Plan R.A.I. Project #2021-136-001 At your request, Raedeke Associates, Inc. staff was retained by the Seattle Seahawks to review existing shoreline conditions as part of the proposed Virginia Mason Athletic Center (VMAC) field resurfacing project. We conducted a site investigation on November 18, 2021 to identify and document the existing conditions of the ordinary high water mark and shoreline buffer along Lake Washington in vicinity of the proposed project. This report is intended to provide a review of the environmental impacts resulting from construction activities required to facilitate the resurfacing of the existing onsite athletic fields and provide a mitigation plan for impacts to the shoreline buffer. This report follows the City of Renton (2021) critical area and shoreline code requirements. SITE LOCATION The VMAC Field Resurfacing project would occur on a portion of an approximately 27- acre property (King County Tax Parcel Nos. 2924059015 and 2924059001) at 12 Seahawks Way in the City of Renton, Washington. The property is located within a portion of Section 29, Township 24 North, Range 5 East, W.M. Parcel maps retrieved Mr. Sean Vanos November 30, 2021 revised January 19, 2022 Page 2 on-line from King County iMap, as well as a site plan received from Mr. Vanos depict the project location and property boundaries. DEFINITIONS AND METHODOLOGIES Wetlands and streams are protected by federal law as well as by state and local regulations. Federal law (Section 404 of the Clean Water Act) prohibits the discharge of dredged or fill material into “Waters of the United States,” including certain wetlands, without a permit from the U.S. Army Corps of Engineers (COE 2021). The COE makes the final determination as to whether an area meets the definition of a wetland and whether the wetland is under their jurisdiction. We based our site investigation upon the guidelines of the U. S. Army Corps of Engineers (COE) Wetlands Delineation Manual (Environmental Laboratory 1987) and subsequent amendments and clarifications provided by the COE (1991a, 1991b, 1992, 1994), as updated for this area by the regional supplement to the COE wetland delineation manual for the Western Mountains, Valleys, and Coast Region (COE 2010). The COE wetland delineation manual is required by state law (WAC 173-22-035, as revised) for all local jurisdictions. As outlined in the COE wetland delineation manual, wetlands are distinguished by the presence of three diagnostic characteristics: hydrophytic vegetation (wetland plants), hydric soil (wetland soil), and wetland hydrology. The ordinary high water mark (OHWM) of streams was determined using definitions provided by the Washington State Shorelines Management Act of 1971: “that mark that will be found by examining the bed and banks and ascertaining where the presence and action of waters are so common and usual, and so long continued in all ordinary years, as to mark upon the soil a character distinct from that of the abutting upland, in respect to vegetation.” (RCW 90.58.030(2)(b) and WAC173-22-030(6). The OHWM was delineated using procedures outlined in the Washington Department of Ecology (2016) Shoreline Administrators Manual and located during the field work using a handheld Geographic Positioning System (GPS) +/- 1-meter accuracy as well as available site survey topographic information, aerial imagery, and available off-site LiDar information. Project History The Virginia Mason Athletic Center (VMAC) was constructed in 2007 and features one indoor and three outdoor, natural grass practice fields for the Seattle Seahawks. The outdoor fields are partially within the 200’ shoreline designation associated with Lake Washington. The City of Renton’s Shoreline Master Program classifies this area as High Intensity. The existing grass fields sit on a minimum 18-inch sand fill layer on top of the 3-foot soil cap. Field maintenance is of highest priority at the VMAC for team success and player safety. Maintenance occurs on an ongoing basis, and it includes continual application of sand to Mr. Sean Vanos November 30, 2021 revised January 19, 2022 Page 3 ensure even grade, and pest mitigation measures pursuant to a robust Turf Integrated Pest Management Plan (“TIPMP”). To maintain these practice fields at the highest professional NFL standards into the future and to restore the original condition, a third- party consultant has recommended resurfacing the grass on a regular, ten-year schedule to abate material accumulation and resulting uneven grading. The Seahawks have worked with turf experts to develop the resurfacing plan proposed with this project. The routine maintenance proposed with this project would commence after the football season such that the fields can be ready for the 2022 training camp. BACKGROUND REVIEW Prior to conducting our site visit, we reviewed existing background maps and information for the project site from the U.S. Fish and Wildlife (USFWS 2021) National Wetland Inventory (NWI), United States Department of Agriculture Natural Resources Conservation Service (USDA NRCS 2018) web soil survey, and King County (2021) iMap. We also reviewed the AECOM (2014) Shoreline Native Vegetation Restoration – Year 5 Monitoring Report for the project site to aid in our understanding of the existing site conditions. We also reviewed the Washington Department of Fish and Wildlife (WDFW 2021) Priority Habitats and Species map to identify documented presence of any endangered or threatened wildlife or their habitat in vicinity of the project site. Finally, we reviewed current and historical aerial photographs (Google Earth 2021) to assist in the definition of existing plant communities, drainage patterns, and land use. EXISTING CONDITIONS Most of the site consists of the existing Seattle Seahawks practice fields. The fields are comprised of a sod/turf mixture that is regularly maintained and mowed. The Lake Washington Shoreline is located west of the project site and an approximately 25-foot- wide restored shoreline buffer exists between the practice facilities and the lake (See Figure 2). For this project, we assessed a relatively small (approximately 480 square feet) portion of the shoreline buffer located in the northwest portion of the project site that may potentially be impacted as part of the field resurfacing activities. The portion of the shoreline buffer we assessed as part of the proposed project contains one, approximately 18-inch dbh (diameter at breast height) balsam poplar (Populus balsamifera, FAC) tree with a scrub-shrub understory of western red arborvitae (Thuja plicata, FAC), redosier dogwood (Cornus alba, FACW), oceanspray (Holodiscus discolor, FACU), snowberry (Symphoricarpos albus, FACU), and hardhack (Spiraea douglasii, FACW). Soils in the shoreline buffer consist of approximately 12 inches of dark brown (10YR 2/2) sandy loam soils over dark brown (10YR 2/2) gravely sandy loam soils with larger Mr. Sean Vanos November 30, 2021 revised January 19, 2022 Page 4 cobbles to a depth of greater than 14 inches. During our site investigation, we did not observe hydric soils nor any primary indicators of wetland hydrology in the shoreline buffer including a water table or saturation within the upper 12 inches of the soil profile or any secondary indicators of wetland hydrology including water-stained leaves, drift deposits, algal matting, or indicators of ponding within the shoreline buffer. Lake Washington OHWM During our site investigation, we observed a clear transition between the upland buffer and the ordinary high-water mark of Lake Washington along the shoreline. During our site investigation, we identified and recorded the approximate location of the Lake Washington ordinary high-water mark using a high-accuracy (sub-meter) Trimble GPS unit. The OHWM corresponds to the location depicted in the AECOM (2014) report and contains existing large cobbles, gravels, and fine sand materials. The OHWM is largely devoid of vegetation except for sparse patches of reed canarygrass (Phalaris arundenacea, FACW) and creeping buttercup (Ranunculus repens, FAC). A concrete retaining wall is located within the shoreline waterward of the OHWM. We did not observe any fringing wetland habitat along lake shoreline in proximity to the proposed work area. REGULATORY CONSIDERATIONS Wetlands are protected by Section 404 of the Federal Clean Water Act and other state and local policies and ordinances. Regulatory considerations pertinent to wetlands identified within the study area are discussed below; however, this discussion should not be considered comprehensive. Additional information may be obtained from agencies with jurisdictional responsibility for, or interest in, the site. A brief review of the U.S. Army Corps of Engineers regulations and City of Renton policy relative to wetlands, is presented below. Federal Clean Waters Act (U.S. Army Corps of Engineers) Federal law (Section 404 of the Clean Water Act) discourages the discharge of dredged or fill material into the nation's waters, including most wetlands and streams, without a permit from the U.S. Army Corps of Engineers (COE). The COE makes the final determination as to whether an area meets the definition of “Waters of the U.S.” as defined by the federal government (Federal Register 1986:41251), and thus, if it is under their jurisdiction. We should caution that the placement of fill within wetlands or other “Waters of the U.S.” without authorization from the COE is not advised, as the COE makes the final determination regarding whether any permits would be required for any proposed alteration (COE 2021). Because the COE makes the final determination regarding permitting under their jurisdiction, a jurisdictional determination from the COE is generally recommended prior to any construction activities, if any modification of Mr. Sean Vanos November 30, 2021 revised January 19, 2022 Page 5 wetlands is proposed. A jurisdictional determination would also provide evaluation and confirmation of the wetland delineations by the COE. Washington State Under Section 401 of the Clean Water Act, an activity involving a discharge in waters of the U.S. authorized by a federal permit must receive water quality certification by the affected certifying agency. In Washington State, the certifying agency is WDOE, which has regulatory authority over waters of the state, including streams and isolated wetlands, under the state Water Pollution Control Act (90.48 RCW) and the Shoreline Management Act (90.58 RCW). City of Renton The City of Renton (2021) code regulates wetlands and streams as critical areas. Alterations of wetlands and their buffers are generally prohibited, except as allowed under certain conditions. All direct wetland impacts must be mitigated through creation, restoration, or enhancement. The City of Renton has the final authority to determine ratings, buffers, and allowed uses of wetlands, their buffers, and other sensitive areas that are under their jurisdiction. The project is located within the Lake Washington shoreline district and would be regulated under the City of Renton (2021) Shoreline Master Program (SMP). The SMP takes jurisdiction over Lake Washington and those areas within 200-feet of the ordinary high-water mark. PROPOSED PROJECT The project proposes to resurface the existing athletic fields located within the 200- feet-wide Lake Washington Shoreline setback. The routine maintenance of the fields would include removal and grading of existing topsoil and installation of new turf/sod. All work would remain within the existing footprint of the athletic fields. To avoid impacts to vehicle traffic, the project proposes to remove excess topsoil by transporting materials via barge on Lake Washington. A small portion of the shoreline buffer would be affected in the northwest portion of the site to accommodate a landing ramp between the barge and shoreline (Figures 2 and 3). The landing ramp would be placed such that it would span over the OHWM from the barge to the shoreline. No impacts are proposed to occur below the OHWM. Prior to any construction activities, the project will employ best management practices (BMPs) to avoid and minimize impacts to Lake Washington and its shoreline buffer. These BMPs would include but would not be limited to: • Installation of silt fence between the work area and Lake Washington Shoreline. • Identification of clearing limits, specifically within the area of proposed shoreline buffer impacts • Clear identification of any trees that would be impacted as part of the project Mr. Sean Vanos November 30, 2021 revised January 19, 2022 Page 6 • Maintaining spill kits on site during all construction work Due to the nature of the project, construction work would need to be completed during the early spring (off-season) to avoid conflict to the Seattle Seahawk practice schedule. PROJECT IMPACTS The proposed project has the potential to impact up to 480 square feet of existing shoreline buffer vegetation. While no grading is anticipated in order to place the barge loading ramp (16 feet wide), some vegetation maybe permanently affected by the project. It is anticipated that similar activities will be required approximately 10 years after this project is completed, as such mitigation has been designed to minimize future impacts to the shoreline buffer area. Mitigation Mitigation has been defined by the State Environmental Policy Act (SEPA) (WAC 197- 11-768; cf. Cooper 1987), and more recently in a Memorandum of Agreement between the Environmental Protection Agency and the COE (Anonymous 1989). In order of desirability, mitigation may include: • Avoidance - avoiding impacts by not taking action or parts of an action; • Minimization - minimizing impacts by limiting the degree or magnitude of the action and its implementation; • Compensatory Mitigation - may involve: a) repairing, rehabilitating, or restoring the affected environment; b) replacing or creating substitute resources or environments; c) mitigation banking. The City of Renton (2021) Shoreline code Section 4-3-090D.2 requires that no net loss of ecological functions will occur as part of a proposed project. Mitigation sequencing for projects is required to demonstrate that all reasonable efforts have been taken to avoid impacts to critical areas and/or sufficient mitigation such as the activity results in no-net loss of ecological functions. Avoidance of Impacts Direct impacts to Lake Washington are not anticipated as part of this project. As noted above, best management practices would be installed prior to any construction activities and would focus on preventing any unintended impacts to the lake or below the ordinary high-water mark. Minimization of Impacts The project would minimize impacts to the shoreline buffer by designated an area for placement of the temporary barge ramp. The ramp would be located near the northwest Mr. Sean Vanos November 30, 2021 revised January 19, 2022 Page 7 corner of the practice fields and would result in 480 square feet of temporary impacts to the shoreline buffer (Figure 2). • Clearly mark the limits of the Lake Washington OHWM prior to construction activities to prevent inadvertent or unnecessary encroachment; • Install and maintain temporary and permanent soil erosion control measures designed to prevent sediment from entering surface waters during and after construction, consistent with best management practices, as required by the City of Renton, including placement of straw bales and silt fencing between work activities and lake Washington; • No work would occur below the OHWM of Lake Washington; • Telephone numbers of appropriate agency/department contacts would be readily available on-site in case a spill should occur (e.g., Washington Department of Ecology, City of Renton Fire Department Hazmat Team, City of Renton Fire and Rescue). Compensatory Mitigation The project will compensate for the buffer impacts by enhancing approximately 580 square feet of buffer after completion of the field resurfacing. Site Preparation Prior to site preparation, the limits of the shoreline buffer planting area would be clearly marked (staked) in the field by appropriate means with the assistance of the project biologist. Plant Species Composition Shrub plantings within the shoreline buffer would consist of low-growing species, such as salal (Gaultheria shallon FACU), Oregon grape (Berberis nervosa UPL), snowberry (Symphoricarpos albus FACU) and clustered roses (Rosa pisocarpa FAC). And lakeshore sedge (Carex lenticularis FACW), lady fern (Athyrium filix-femina FAC) in the wet buffer area (Figure 3). Care should be taken to not plant trees or tall shrub species within the area of the temporary barge ramp as it is anticipated that additional resurfacing activities will be required in the future. All plantings would be installed in pits that are approximately twice the diameter of the root ball. Soil amendment consisting of compost from a permitted solid waste composting facility would be added, if needed, to planting backfill to promote plant establishment and vigorous growth. Shredded bark mulch would be installed in 24-inch collars around each planting to prevent or minimize establishment of invasive plant species and to conserve soil moisture. Mr. Sean Vanos November 30, 2021 revised January 19, 2022 Page 8 Planting Schedule Planting would occur between October 1 and March 1 to take advantage of seasonal rains and greater availability of plant material. Planting at any other time or during periods of abnormally hot, dry, or freezing weather conditions would not occur without prior approval by the project biologist and may require plant substitutions and supplemental irrigation. Installation and Compliance Monitoring This plan includes a systematic monitoring program of the proposed shoreline buffer restoration to evaluate the success of the mitigation efforts. The results of the monitoring will be used to develop modifications, if needed, to the mitigation plan in subsequent years. The purposes of the monitoring program are as follows: (1) to document physical and biological characteristics of the enhanced wetland buffers, and (2) to ensure that the goals and objectives comply with permit specifications. The monitoring program for the buffer restoration would begin with installation and compliance monitoring. The project biologist would be present on-site during the various stages of installation of the mitigation plantings in order to: (1) demark the limits of the areas to be planted; (2) review and approve the plant materials and recommend their final placement before planting; (3) make adjustments in planting plans, as needed, in response to field conditions; (4) ensure that construction activities are conducted per the approved plan; and (5) resolve problems that arise during construction, thus lessening problems that might occur later during the long-term monitoring phase. Compliance monitoring consists of evaluating the buffer enhancement area immediately after grading and planting activities are completed. The objectives would be to verify that all design features, as agreed to in the buffer enhancement planting plan, have been correctly and fully implemented, and that any changes made in the field are consistent with the intent and the design of the approved plan. Evaluation of the planting areas after implementation would be done by the project biologist using evaluation standards and criteria detailed below. After planting of the buffer areas are completed, plant counts would be collected during each of the subsequent monitoring of the site during the five-year, long-term monitoring. Photos would be taken to document “time-zero” conditions from which long-term monitoring period would begin. The compliance monitoring phase would conclude with the preparation of a brief compliance report by the project biologist. The report would document whether all design features have been correctly, fully, and successfully implemented. Substantive changes made in the planting plans would be noted in the compliance report and on the drawings for use during the long-term monitoring phase. Locations of monitoring sample plots established for the compliance monitoring, if needed, would be identified on the as- built plans. Mr. Sean Vanos November 30, 2021 revised January 19, 2022 Page 9 The planting plans along with the compliance report, would document “as-built” conditions at the time of construction compliance. The compliance report and as-built plan would be submitted to the City of Renton for review and approval. Long-Term Monitoring The long-term monitoring program will begin following approval of the mitigation compliance monitoring report and would be conducted annually for the five-year monitoring period. Long-term monitoring would evaluate the establishment and maintenance of the plant communities in the shoreline setback to determine if the goals and objectives of the mitigation plan have been met. Within each planting area, plant species would be identified, and the combined areal cover percentage for all native planted and volunteer woody species would be estimated. In addition, plant counts would be made following completion of the first growing season and each subsequent monitoring season to document the overall percent survival of the tree and shrub plantings. Notes on invasive species and overall site stability would also be documented during the annual monitoring period. Plant identifications would be made according to standard taxonomic procedures described in Hitchcock and Cronquist (1976), with nomenclature as updated by the U.S. Army Corps of Engineers National Wetland Plant List (Lichvar et al. 2016). Photos would be taken within the mitigation planting areas during each monitoring year (years 1, 2 3, 4, and 5). Photographs would be taken from locations established during the compliance monitoring site visit. Monitoring and Reporting Schedule Formal monitoring of the enhanced wetland buffer would occur at the end of the growing season (late-August or September) of each year of the five-year long-term monitoring program. In addition, during the first two growing seasons, the project biologist would also evaluate the mitigation site during spring and mid-summer to assess site progress and to determine whether maintenance is needed to ensure success of the buffer enhancement areas in attaining the goals and objectives of the mitigation plan. Monitoring reports would be prepared following the completion of the growing season of years 1, 2, 3, 4, and 5 of the long-term monitoring period and submitted to the City for review and approval. The long-term monitoring period will commence following acceptance of the compliance report and “as-built” drawings by the City of Renton. Monitoring reports would be submitted to the City as soon as possible after the monitoring has been completed, with a target date of December 31 of each monitoring year. The report would document conditions within the enhanced areas and make recommendations for correcting any problems encountered. Mr. Sean Vanos November 30, 2021 revised January 19, 2022 Page 10 EVALUATION AND PERFORMANCE STANDARDS Specific performance standards to be used in the five-year long-term monitoring are the following: • 100% survival of all planted shrubs following completion of the first year after planting. All plantings that do not survive during the first year must be replaced with the same or similar species and specifications. Upon installation of replacement plantings at the conclusion of the first year, the 100% survival performance standard will be considered to be met; • Coverage by shrub species (volunteer and planted individuals) will be the following: ▪ at least 5% after one year ▪ at least 15% after two years; ▪ at least 40% after five years; • There will be no more than 10% cover by Himalayan blackberry (Rubus armeniacus) or cutleaf blackberry (Rubus lacinatus), Scotch broom (Cytisus scoparius), reed canarygrass (Phalaris arundinacea), or other invasive plant species, as identified by the project biologist during the five-year monitoring period. As outlined above, the proposed site plan includes removal of all non-native vegetation from within the vegetation enhancement zone and installation of native shrubs to compensate for the approximately 170 square feet of buffer encroachment. Restoration would improve the habitat and functionality of the shoreline buffer. CONTINGENCY PLAN Contingency plans are needed if post-buffer enhancement monitoring shows that objectives and performance standards have not been met. It should be noted, however, that it is not possible to develop a detailed contingency plan until the specific problems that need to be addressed are known. It would be unproductive to try to anticipate all possible problems and their solutions at this time. Implementation of a contingency plan may require extension of the monitoring phase of the project, especially if major changes in the plan are required. The project biologist should make recommendations for identified problems. All contingency measures must be reviewed and approved by the City of Renton. LIMITATIONS We have prepared this report for the exclusive use by the Seattle Seahawks and their consultants. No other person or agency may rely upon the information, analysis, or conclusions contained herein without permission from the Seattle Seahawks. Mr. Sean Vanos November 30, 2021 revised January 19, 2022 Page 11 The determination of ecological system classifications, functions, values, and boundaries is an inexact science, and different individuals and agencies may reach different conclusions. With regard to wetlands, the final determination of their boundaries for regulatory purposes is the responsibility of the various agencies that regulate development activities in wetlands. We cannot guarantee the outcome of such determinations. Therefore, the conclusions of this report should be reviewed by the appropriate regulatory agencies. We warrant that the work performed conforms to standards generally accepted in our field and prepared substantially in accordance with then-current technical guidelines and criteria. The conclusions of this report represent the results of our analysis of the information provided by the project proponent and their consultants, together with information gathered in the course of the study. No other warranty, expressed or implied, is made. Thank you for the opportunity to prepare this material for you. Please let us know if you have any questions or need additional information. LITERATURE CITIED AECOM. 2014. Shoreline Buffer Native Vegetation Restoration – Year 5 Monitoring Report, Virginia Mason Athletic Center, Seattle Seahawks Headquarters and Training Facility, Renton, WA. January 2014 report to Football Northwest, LLC, Seattle, Washington. Anonymous. 1989. Memorandum of Agreement between the U.S. Environmental Protection Agency and the Department of Army Concerning the Determination of Mitigation under the Clean Water Act, Section 404 B1 Guidelines. Effective 7 November 1989. Cooper, J. 1987. An overview of estuarine habitat mitigation projects in Washington State. Northwest Environmental Journal 3(1): 112-127. Cowardin, L., F. Golet, V. Carter, and E. LaRoe. 1992. Classification of wetlands and deepwater habitats of the United States. U.S.D.I. Fish and Wildlife Service Publ. FWS/OBS-79/31. 103 pp. Environmental Laboratory. 1987. Corps of Engineers Wetlands Delineation Manual. Technical Report Y-87-1, US Army Engineers Waterways Experiment Station, Vicksburg, Mississippi. 100 pp. Federal Register. 1986. 40 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, D.C. Mr. Sean Vanos November 30, 2021 revised January 19, 2022 Page 12 Federal Register. 1995. U.S. Department of Agriculture, Soil Conservation Service: Changes in Hydric Soils of the United States. Volume 59, No 133, July 13, 1994. Revised September 15, 1995. Google Earth. 2021. Image for 47.535497° -122.199832° in the City of Renton, WA. © 2021 Google. Accessed November 2021. Hitchcock, C., and A. Cronquist. 1976. Flora of the Pacific Northwest. Univ. of Washington Press, Seattle, Washington. 730 pp. King County. 2021. iMAP GIS Interactive map center, King County, Washington. http://www.metrokc.gov/gis/iMAP_main.htm#. Accessed November 2021. Lichvar, R.W., D.L. Banks, W.N. Kirchner, and N.C. Melvin. 2016. The National Wetland Plant List: 2016 wetland ratings. Phytoneuron 2016-30: 1-17. Published 28 April 2016. ISSN 2153 733X. Available at: http://wetland- plants.usace.army.mil/nwpl_static/home/home.html. Renton, City of. 2021. Renton Municipal Code. Title IV Chapter 3 Environmental Regulations and Overlay Districts. Current through Ordinance 6029, passed October 18, 2021. Available at: https://www.codepublishing.com/WA/Renton/html/Renton04/Renton0403/Renton 0403.html. U.S. Army Corps of Engineers. 1991a. Special notice. Subject: Use of the 1987 wetland delineation manual. U.S. Army Corps of Engineers, Seattle District. August 30, 1991. U.S. Army Corps of Engineers. 1991b. Memorandum. Subject: Questions and answers on the 1987 manual. U.S. Army Corps of Engineers, Washington D.C. October 7, 1991. 7 pp. including cover letter by John P. Studt, Chief, Regulatory Branch. U.S. Army Corps of Engineers. 1992. Memorandum. Subject: Clarification and interpretation of the 1987 methodology. U.S. Army Corps of Engineers, Washington D.C., March 26, 1992. 4 pp. Arthur E. Williams, Major General, U.S.A. Directorate of Civil Works. U.S. Army Corps of Engineers. 1994. Public Notice. Subject: Washington regional guidance on the 1987 wetland delineation manual. May 23, 1994, Seattle District. 8 pp. U.S. Army Corps of Engineers. 2010. Regional supplement to the Corps of Engineers wetland delineation manual: western mountains, valleys, and coast region (Version 2.0). Wakeley, J.S., R.W. Lichvar, and C.V. Noble, eds. May 2010. Mr. Sean Vanos November 30, 2021 revised January 19, 2022 Page 13 ERDC/EL TR-10-3. U.S. Army Engineer Research and Development Center, Vicksburg, MS. U.S. Army Corps of Engineers. 2021. Special Public Notice. Final Seattle District 2017 Nationwide Permit Regional Conditions for Nationwide Permits for the Seattle District Corps of Engineers for the State of Washington. U.S. Army Corps of Engineers, Seattle District. March 3, 2021. U.S.D.A. Natural Resources Conservation Service. 2021. On-line Web Soil Survey. http://websoilsurvey.nrcs.usda.gov. Accessed November 2021. U.S.D.A., Soil Conservation Service. 1991. Hydric soils of the United States: In cooperation with the National Technical Committee for Hydric Soils. U.S.D.A. Miscellaneous Publication Number 1491. U.S. Fish and Wildlife Service. 2021. National Wetland Inventory, Wetlands Online Mapper. http://wetlandsfws.er.usgs.gov/wtlnds/launch.html. Accessed November 2021. Washington Department of Ecology. 2016. Determining the Ordinary High Water Mark for Shoreline Management Act Compliance in Washington State. October 2016. Publication number 16-06-029 Washington Department of Fish and Wildlife. 2020. Hydraulic Project Approval. http://wdfw.wa.gov/licensing/hpa/. Washington Department of Fish and Wildlife. 2021. Priority Habitat and Species database. https://geodataservices.wdfw.wa.gov/hp/phs/. Accessed November 2021. FIGURES EXISTING CONDITIONS LEGEND: DELINEATED OHWM** EXISTING OUTFALL (APPROX) BARGE RAMP AREA (APPROX) 16 FEET WIDE ** SHORELINE OHWM DELINEATED ON 2021-11-18 BASED ON HAND HELD GPS COORDINATES AND ARE NOT SURVEYED. BOUNDARIES ARE APPROXIMATE AND FOR PLANNING PURPOSE ONLY. PROPOSED CONDITIONS LEGEND: ORDINARY HIGH WATER MARK (OHWM) OBSERVED ON 2021-11-18 EXISTING OUTFALL BARGE RAMP AREA (APPROXIMATE)16.010.0Associates, Inc. 2111 N. Northgate Way, Ste 219 Seattle, WA 98133 Raedeke KING COUNTY 2017 AERIAL SCALE: 1" = 10' NORTH 0 5'10'20' LEGEND FIGURE RAI PROJECT: DATE: DRAWN BY:PM: BASE INFORMATION: EXISTING CONDITIONS VMAC Field Resurfacing CITY OF RENTON, WA 2 KKSS 12/01/2021 2021-136-001 PROJECT SITE INFORMATION ADDRESS 12 SEAHAWKS WAY IN THE CITY OF RENTON, WASHINGTON. KING COUNTY PARCEL NO.2924059015 and 2924059001 PREPARED FOR SEATTLE SEAHAWKS PREPARED BY RAEDEKE ASSOCIATES INC EXISTING CONDITIONS LEGEND: DELINEATED OHWM** EXISTING OUTFALL (APPROX)16.010.0PROPOSED CONDITIONS LEGEND: BUFFER RESTORATION ZONE 1 (390 SQ.FT) BUFFER RESTORATION ZONE 2 (190 SQ.FT) KING COUNTY 2017 AERIAL SCALE: 1" = 10' NORTH 0 5'10'20' LEGEND Associates, Inc. 2111 N. Northgate Way, Ste 219 Seattle, WA 98133 Raedeke FIGURE RAI PROJECT: DATE: DRAWN BY:PM: BASE INFORMATION: BUFFER ENHANCEMENT PLAN VMAC Field Resurfacing CITY OF RENTON, WA 3 KKSS 12/01/2021 2021-136-001 SCIENTIFIC NAME COMMON NAME WIS STATUS MIN. SIZE (container)SPACING QTY. Berberis nervosa short oregon grape UPL 2 gal.5 FT O.C.5 Gaultheria shallon Salal FACU 2 gal.5 FT O.C.5 Rosa pisocarpa clustered rose FAC 2 gal.5 FT O.C.3 Rosa nutkana Nootka rose FAC 2 gal.5 FT O.C.3 Symphoricarpos albus Snowberry FACU 2 gal.5 FT O.C.3 BUFFER RESTORATION ZONE 1 (DRY UPLAND BUFFER) SCIENTIFIC NAME COMMON NAME WIS STATUS MIN. SIZE (container)SPACING QTY. Rosa pisocarpa clustered rose FAC 2 gal.5 FT O.C.4 Rosa nutkana Nootka rose FAC 2 gal.5 FT O.C.3 Carex lenticularis Shore sedge FACW 1 gal.3 FT O.C.10 Athyrium filix-femina Lady fern FAC 1 gal.3 FT O.C.15 BUFFER RESTORATION ZONE 2 (WET BUFFER) FIGURE RAI PROJECT: DATE: DRAWN BY:PM: BASE INFORMATION: PLANTING DETAILS VMAC Field Resurfacing CITY OF RENTON, WA 4 KKSS 11/29/2021 2021-136-001 Associates, Inc. 2111 N. Northgate Way, Ste 219 Seattle, WA 98133 Raedeke SPAC I N G V A R I E S TYPICAL GROUND COVER PLANTED AT NURSERY LEVEL MIN 2"MULCH FINISH GRADE SEE L A N D S C A P E D R A W I N G S MIN 6" SOIL DEPTH 50/50 WITH NATIVE SOIL OR IMPORTED SOIL AMENDEDED WITH COMPOST EXISTING SUBGRADEGROUNDCOVER PLANTING ON SLOPE; TYP.1 SET TOP OF ROOTBALL FLUSH WITH GRADE. 2-3 IN. MULCH. DO NOT PUT MULCH AGAINST PLANT STEM. DIG PLANTING PIT 2 TIMES AS WIDE AS ROOTBALL BUT NOT DEEPER THAN THE ROOTBALL. FINISH GRADE REMOVE CONTAINER COMPLETELY. LOOSEN ROOTS OR TEASE APART ROOTS THAT ARE TIGHTLY BOUND BACKFILL WITH SOIL PER SPECIFICATIONS PLACE ROOTBALL ON UNEXCAVATED OR TAMPED SOIL (SO PLANT DOES NOT SINK). CONTAINERIZED PLANT (TYP.) SHRUB CONTAINER PLANTING; TYP.2 FIGURE RAI PROJECT: DATE: DRAWN BY:PM: BASE INFORMATION: PLANTING SPECIFICATIONS VMAC Field Resurfacing CITY OF RENTON, WA 5 KKSS 11/29/2021 2021-136-001 1.0 GENERAL CONDITIONS 1.1 GENERAL DESCRIPTION &URNISH ALL MATERIALS͕ TOOLS͕ EQUIPMENT͕ AND LABOR NECESSARY &OR THE COMPLETION O& SITE PREPARATION AND PLANTING͕ AS INDICATED ON DRAWINGS AND SPECI&IED HEREINA&TER. WORK INCLUDES REMOVAL O& INVASIVE PLANT SPECIES BY HAND METHODS͕ PLANTING͕ MULCHING͕ AND GUARANTEE O& PLANTED AREAS AS SPECI&IED HEREIN. THE OB:ECTIVE O& THE PLAN IS TO REͲVEGETATE THE IMPACTED SHORELINE BU&&ER WITH A NATIVE PLANTS. THE ROOTS O& THE NATIVE PLANTS WILL HELP STABILIE THE BU&&ER TEMPORARILY DISTURBED DUE TO PLACEMENT O& BARGE RAMP. 1.2 CONSTRUCTION OBSERVATION / QUALITY ASSURANCE / GUARANTEE THE PRO:ECT BIOLOGIST SHALL BE INVOLVED DURING THE &OLLOWING PHASES O& CONSTRUCTION͗ ;1Ϳ ONͲSITE MEETING PRIOR TO COMMENCEMENT O& WORK IN ;PREͲCONSTRUCTION MEETINGͿ͕ &LAG BARGE IMPACT AREA LIMITS. ;2Ϳ TEMPORARY EROSION AND SEDIMENT CONTROL MEASURES AND SITE PROTECTION ;EyISTING BU&&ER AND TREES PROTECTION Ϳ PLAN VERI&ICATION AS PER CIVIL PLAN. ;3Ϳ APPROVAL O& NURSERY STOCK͕ TREE AND SHRUB PLANTING LOCATIONS AND PLACEMENT͖ AND ;4Ϳ &INAL INSPECTION. 1.CONTRACTOR WILL &LAG ALL PLANTING AREAS &OR PRO:ECT BIOLOGIST APPROVAL ;SPECIES͕ QUANTITY͕ SIE͕ CONDITIONͿ PER APPROVED PLANS. CONTRACTOR WILL WALK THE SITE WITH THE PRO:ECT BIOLOGIST TO CLARI&Y LIMITS O& RESUR&ACING OPERATION AND THE WORK TO BE PER&ORMED. 2.CONTRACTOR SHALL INSTALL PLANTS AS DIRECTED IN THE PLANS AND BIOLOGIST WILL APPROVE PLANT INSTALLATION. PLANT SUBSTITUTIONS MAY BE PERMITTED BASED ON PLANT AVAILABILITY͕ BUT ONLY WITH PRIOR APPROVAL O& THE BIOLOGIST. 3.THE CONTRACTOR SHALL &URNISH CERTI&ICATES O& INSPECTION AND COMPLIANCE TO THE PRO:ECT BIOLOGIST AS REQUIRED BY &EDERAL AND STATE LAWS AND REGULATIONS &OR ALL PLANT MATERIALS͕ SOIL AMENDMENTS͕ RECEIPTS͕ DELIVERY SLIPS͕ PLANT TAGS͕ AND &ERTILIERS USED IN THE PRO:ECT. 2.0 SITE PREPARATION AND EXECUTION 2.1 SITE CLEANUP 1.THE PRO:ECT BIOLOGIST SHALL BE NOTI&IED IMMEDIATELY I& SITE CONDITIONS DI&&ER &ROM THOSE SHOWN IN THE PLANS. 2.ALL EyISTING VEGETATION OUTSIDE LIMITS O& PLANTING SHALL BE PROTECTED UNLESS SPECI&IED. ANY EyISTING VEGETATION DAMAGED BY CONTRACTOR SHALL BE REPLACED WITH PLANTS O& EQUAL OR BETTER SIE AND CONDITION AT CONTRACTORΖS EyPENSE. 3.THE CONTRACTOR SHALL BE RESPONSIBLE &OR KEEPING PLANTED AREAS &REE O& DEBRIS. UPON COMPLETION O& THE WORK͕ THE CONTRACTOR SHALL REMOVE ALL SURPLUS MATERIAL͕ EQUIPMENT͕ AND DEBRIS &ROM THE SITES. ALL PLANTED AREAS SHALL BE RAKEͲCLEAN. 2.2 SITE PREPARATION 4.THE CONTRACTOR SHALL &ENCE OR STAKE THE BARGE IMPACT AREA BOUNDARY PRIOR TO STARTING O& ANY WORK IN THE BU&&ER. ϱ.INSTALL A SILT &ENCE ;MINIMUM 3Ζ HEIGHTͿ AROUND THE SHORELINE BU&&ER PRIOR TO THE RESUR&ACING OPERATION. TEMPORARY EROSION AND SEDIMENT CONTROL MEASURES SHALL BE INSTALLED AS PER CIVIL PLANS. ϱ.SOIL DISTURBING ACTIVITIES WITHIN THE PLANTING BU&&ER͕ INCLUDING BUT NOT LIMITED TO REMOVAL PLANTING OR REMOVAL O& INVASIVE SPECIES͕ SHALL OCCUR BETWEEN MARCH 1 AND OCTOBER 1 UNLESS OTHERWISE APPROVED BY THE PRO:ECT BIOLOGIST OR UNLESS OTHERWISE REQUIRED BY STATE OR &EDERAL AGENCIES &OR PERMITS THAT MAY BE REQUIRED &OR PRO:ECT IMPLEMENTATION. EyISTING IRRIGATION SYSTEM ON SITE SHALL BE PROTECTED DURING RESUR&ACING OPERATION. ϲ.TEMPORARY EROSION AND SEDIMENT CONTROL MEASURES AROUND EyISTING STORM INLET SHALL BE REMOVED ONLY A&TER PLANTINGS HAVE &ULLY ESTABLISHED IN THE BU&&ER. ϳ.PRIOR TO PLANTING ALL NONͲORGANIC DEBRIS AND NONͲNATIVE PLANTS SHALL BE REMOVED AND EyPORTED O&&ͲSITE. WALK BU&&ER RESTORATION SITE WITH THE PRO:ECT BIOLOGIST TO IDENTI&Y LIMITS O& INVASIVE SPECIES REMOVAL. ϴ.REMOVE INVASIVE PLANT AND ROOT SOURCES THAT WOULD NEGATIVELY IMPACT THE PLANTING. INVASIVE SPECIES WILL BE REMOVED BY GRUBBING OUT ROOT MASS. INVASIVE SPECIES REMOVAL MAY EyTEND BEYOND THE PRO:ECT BOUNDARIES. ALL NONͲNATIVE͕ INVASIVE SPECIES INCLUDING ALL PLANT PARTS MUST BE REMOVED &ROM PRO:ECT SITE AND DISPOSED AT A &ACILITY THAT ACCEPTS YARD WASTE. ϵ.ONͲSITE ;NATIVEͿ TOPSOIL CAN BE USED &OR PLANTING AS BACK&ILL. OTHERWISE͕ ALL IMPORTED TOPSOIL SHALL PASS THROUGH A 1Η SCREEN. 1Ϭ.PLANTING BACK&ILL SHALL CONSIST O& ϱϬͲϱϬ ONͲSITE TOPSOILн ORGANIC COMPOST AMENDMENT. PLANTS SHALL BE INSTALLED SO &INISH GRADE IS LEVEL WITH TOP O& ROOT BALL. 11.PLANTS SHALL BE BACK&ILLED AND WATERͲSETTLED I& SOIL IS DRY. NO COMPACTION O& BACK&ILL IS TO OCCUR AROUND THE NEWLY PLANTED AREA. ALL PLANTS SHALL BE WATERED THOROUGHLY AT TIME O& INSTALLATION. 12.PLANTING SHALL BE INSTALLED IN COMPLIANCE WITH DETAILS IN THIS PLAN. DIG PITS &OR TREES͕ SHRUBS͕ AND GROUNDCOVER 2 TIMES AS WIDE AND 1.ϱ TIMES AS DEEP AS THE DIMENSIONS O& THE CONTAINER. 13.A 2Η TO 3Η LAYER O& BARK CHIPS SHALL BE PLACED CONTINUOUSLY AND EVENLY THROUGHOUT THE PLANTED AREA &OR EROSION͕ WEED CONTROL͕ AND MOISTURE RETENTION. 2.3 IRRIGATION 1.EyISTING IRRIGATION SYSTEM ON SITE SHALL BE PROTECTED DURING RESUR&ACING OPERATION. THE IRRIGATION SYSTEM SHALL BE OPERATE AND MAINTAINED &OR AT LEAST TWO YEARS. 2.I& EyISTING IRRIGATION LINE IS REMOVED͕ A TEMPORARY IRRIGATION SYSTEM SHALL BE INSTALLED BY THE CONTRACTOR. THE CLIENT SHALL PROVIDE WATER AND ELECTRICITY &OR THE SYSTEM AS NEEDED. THE IRRIGATION SYSTEM SHALL PROVIDE AT MINIMUM 1͟ O& WATER PER WEEKΗ TO THE PLANTING AREA &ROM MAY 1 TO SEPTEMBER 3Ϭ &OR 2 YEARS. 3.DURING THE SUMMER MONTHS ;MAYͲSEPTEMBERͿ A&TER INSTALLATION͕ THE IRRIGATION SYSTEM SHALL BE PROGRAMMED TO PROVIDE ΗONE INCH WATER PER WEEK͕ Η. 4.THE IRRIGATION BID SHALL INCLUDE A ONEͲYEAR WARRANTY AGAINST DE&ECTS IN MATERIALS AND WORKMANSHIP &ROM THE DATE O& &INAL PRO:ECT ACCEPTANCE. THE WARRANTY SHALL INCLUDE SYSTEM ACTIVATION AND WINTERIATION &OR THE &IRST YEAR AND IMMEDIATE REPAIR O& THE SYSTEM I& IT IS OBSERVED TO BE MAL&UNCTIONING. 2.4 PLANT ACCEPTANCE AND GUARANTEE PERIOD 1.&OLLOWING COMPLETION O& THE INSTALLATION O& THE BU&&ER RESTORATION PLANTING BY CONTRACTOR AND &INAL APPROVAL BY THE PRO:ECT BIOLOGIST͕ THE PLANTING WARRANTY PROVIDED BY CONTRACTOR SHALL BE IN E&&ECT. &ROM THIS DATE &ORWARD͕ &OR A PERIOD O& ONE YEAR͕ A 1ϬϬй SURVIAL O& NEWLY INSTALLED PLANT MATERIAL IS REQUIRED UNDER THIS GUARANTEE. 2.I& MORTALITY OCCURS DURING THIS PERIOD͕ THE PRO:ECT BIOLOGIST WILL SPECI&Y WHICH PLANTS WILL BE REPLACED BY CONTRACTOR. SPECI&IED PLANTS SHALL BE REPLACED WITH PLANTS O& SPECIES͕ SIES͕ AND CONDITIONS SHOWN ON THE DRAWINGS UNLESS DIRECTED OTHERWISE BY THE PRO:ECT BIOLOGIST IN WRITING. 3.AT THE END O& THE ONEͲYEAR WARRANTY PERIOD͕ AND &OLLOWING REPLACEMENT O& ANY DEAD OR DE&ECTIVE PLANT MATERIAL BY THE CONTRACTOR͕ THE PRO:ECT BIOLOGIST WILL CERTI&Y IN WRITING THE PLANT MATERIAL IS SUITABLE AND HAS BEEN ACCEPTED AND THAT THE ONEͲYEAR WARRANTY IS NO LONGER IN E&&ECT. 4.AT THE END O& THE LONGͲTERM MONITORING PERIOD A &INAL INSPECTION O& THE WORK WILL BE COMPLETED BY THE PRO:ECT BIOLOGIST. PLANTS INSTALLED UNDER THIS CONTRACT THAT ARE DEAD OR IN OTHERWISE UNSATIS&ACTORY CONDITIONS AND BELOW THE ϴϱй SURVIVAL RATE SHALL BE REMOVED &ROM THE SITE AND REPLACED. UPON COMPLETION O& THESE REQUIREMENTS͕ &INAL PLANT ACCEPTANCE WILL BE CERTI&IED IN WRITING BY THE BIOLOGIST. 3.0 PRODUCTS 3.1 ORGANIC COMPOST 1.A WELLͲDECOMPOSED͕ HUMUSͲLIKE MATERIAL DERIVED &ROM THE DECOMPOSITION O& GRASS CLIPPINGS LEAVES͕ BRANCHES͕ WOOD͕ AND OTHER ORGANIC MATERIALS. COMPOST SHALL BE PRODUCED AT A PERMITTED SOLID WASTE COMPOSTING &ACILITY ;HEALTH PERMIT͕ WDOE STORMWATER PERMIT͕ PSAPCA &ACILITY͕ AND EQUIPMENT REGISTRATIONͿ. COMPOST MUST MEET THE DE&INITION O& ͞COMPOSTED MATERIALS͟ IN WAC 1ϳ3Ͳ3ϱϬͲ22Ϭ. THIS CODE IS AVAILABLE ONͲLINE AT͗ HTTP͗//WWW.ECY.WA.GOV/PROGRAMS/SW&A/&ACILITIES//3ϱϬ.HTML 2.THE BACK&ILL SOIL AMENDMENT MUST ALSO MEET THE &OLLOWING SPECI&ICATIONS͗ SCREEN SIE ;APPROy. PARTICLE SEͿ͗ 3/4ͲINCH MAyIMUM MATURITY͗ GREATER THAN ϴϬй MATURITY MEASURE ;C/N RATIOͿ͗ 3ϱ͗1 MAyIMUM ORGANIC MATTER CONTENT BY DRY WEIGHT͗ 3ϱй TO ϴϬй MEETS CONTAMINANT STANDARDS &OR GRADE A COMPOST 3.2 PLANT MATERIALS 1.ALL PLANT MATERIAL SHALL BE LOCALLY GROWN AND BE O& ACCEPTED SIE STANDARDS AS SPECI&IED IN ΗAMERICAN STANDARD &OR NURSERY STOCK Ͳ 2Ϭ14Η PUBLISHED BY THE AMERICAN ASSOCIATION O& NURSERYMEN ;ANSI ϲϬ.1Ͳ2Ϭ14VͿ. 2.ROOTED PLANTS SHALL BE &IRST QUALITY͕ WELLͲ&OLIATED͕ WITH WELLͲDEVELOPED ROOT SYSTEMS͕ AND NORMAL WELLͲSHAPED TRUNKS͕ LIMBS͕ STEMS͕ AND LEADS. THE PRO:ECT BIOLOGIST/INSPECTOR SHALL INSPECT &OR QUALITY CON&ORMANCE. 3.ALL ROOTED PLANT MATERIAL SHALL BE LABELED BY GENUS AND SPECIES. PLANTS DEEMED UNSUITABLE SHALL BE RE:ECTED BE&ORE OR A&TER DELIVERY. 4.ALL PLANT MATERIAL SHALL BE &REE &ROM DAMAGE͕ DISEASE͕ INSECTS͕ INSECT EGGS AND LARVAE. BARE ROOT MATERIAL MAY BE USED I& PLANT MATERIAL IS INSTALLED BETWEEN &EBRUARYͲ MARCH. 3.3 BARK AND STRAW MULCH 1.BARK MULCH SHALL CONSIST O& GROUND &IR OR HEMLOCK BARK O& UNI&ORM COLOR͕ &REE &ROM WEED͕ SEEDS͕ SAWDUST͕ AND SPLINTERS AND SHALL NOT CONTAIN SALTS͕ OR OTHER COMPONENTS DETRIMENTAL TO PLANT LI&E. SIE RANGE O& MULCH SHALL BE &ROM 1/2Η TO 1Ͳ1/4Η WITH MAyIMUM O& 2Ϭй PASSING A 1/2Η SCREEN. STRAW MULCH WILL CONSIST O& STRAW &REE &ROM WEED SEEDS.