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HomeMy WebLinkAboutPN_Environmental_Review_200309.pdf 214 E GALER STREET, SUITE 300, SEATTLE, WA 98102  206.233.9639 MAIN  866.727.0140 FAX  PBSUSA.COM Memorandum DATE: March 9, 2020 TO: City of Renton, Permitting Desk FROM: Tim Ogden PROJECT: 40245.009 REGARDING: Environmental Review – Project Narrative Chelan Ave NE Residential Demolition, Renton School District BACKGROUND Renton School District has acquired 13 residential properties on the 1100 block of Chelan Ave. NE in Renton, WA, south of NE 12th St. in advance of development of a new elementary school near Hazen High School west of Duvall Road NE. The homes have been vacated and are an attractive nuisance, with trespassing/squatting already becoming an issue within weeks of the homes being vacated. The District desires to demolish all structures on the properties that the District has acquired to date. One property in the vicinity has not been acquired by the District and is anticipated to remain occupied for the duration of the planned demolition and stabilization work. Renton SD has retained PBS Engineering and Environmental Inc. (PBS) to serve as the prime consultant for completion of good faith hazardous materials surveys, development of bidding documents (including asbestos abatement and other compliance activities) and construction period services. PBS has completed initial bidding documents that are provided in support of the desired demolition permits. Critical tasks include protection of the mapped wetlands and their buffer zones, establishing tree protection compliant with City of Renton (COR) codes and that will facilitate access to the structures to be demolished, removal of septic tanks that lie within tree protection or wetland buffers and overall erosion and sediment control. Studies completed to date include the Wetland Delineation Report completed by The Watershed Company, Inc. and dated 9/30/19 (provided with pre-application materials). Terrrane has completed an ALTSA/NSPS Land Title Survey of the properties dated 10/12/19 (updated 10/15/19 and provided with pre-application materials) and a tree inventory. Associated Earth Sciences Inc. has completed an Updated Subsurface Exploration and Geotechnical Feasibility Study dated 10/15/19. PBS has completed “good faith” inspections of the structures for the presence of regulated/hazardous materials such as asbestos and lead. City of Renton Permitting Project Narrative – Chelan Ave NE Residential Demo Phase 1 February 7, 2020 Page 2 40245.009 SUBJECT PROPERTIES The following parcels are included in the proposed work:  Parcel No. 2: 1146 Chelan Ave NE, parcel no. 102305-9173 (SFR, shed)  Parcel No. 3: 1137 Chelan Ave NE, parcel no. 102305-9275 (SFR, garage)  Parcel No. 4: 1138 Chelan Ave NE, parcel no. 102305-9096 (SFR, garage, shed)  Parcel No. 5: 1123 Chelan Ave NE, parcel no. 102305-9107 (SFR, garage)  Parcel No. 6: 1128 Chelan Ave NE, parcel no. 102305-9249 (mobile homes)  Parcel No. 7: 1103 Chelan Ave NE, parcel no. 102305-9138 (SFR, garage, shed)  Parcel No. 8: Right of Way – No work  Parcel No. 9: 1102 Chelan Ave NE, parcel no. 102305-9124 (SFR, garage)  Parcel No. 10: Unaddressed, parcel no. 102305-9076 (same prev. owner as 1103/-9138)  Parcel No. 11: 1070 Chelan Ave NE, parcel no. 102305-9202 (SFR, sheds)  Parcel No. 12: 1058/1030 Chelan Ave NE, parcel no. 102305-9332 (SFR, sheds, mobile homes)  Parcel No. 13: 1051 Chelan Ave NE, parcel no. 102305-9133 - Occupied  Parcel No. 14: 1012/1024 Chelan Ave NE, parcel no. 102305-9139 (collapsed wooden shed) PROPOSED WORK The proposed work will include demolition of all structures once SEPA review, NDPES General Stormwater permitting and all required City of Renton environmental review regarding the wetlands and demolition permitting has been completed. Development of the parcels into a new elementary school is slated to follow in approximately 18-24 months once designed and permitted. Select parcels include mapped wetlands and steep slope critical areas. These are outlined in the Wetland Delineation Report completed by The Watershed Company, Inc., 9/30/19, and on City of Renton GIS, and are summarized below. The work will include required erosion control best management practices around the portions of the structures that exist within the buffers, and steep slopes will be protected per City and WSDOT Standard Details. Ground disturbance and vegetation removal will be limited to only that necessary to remove the attractive nuisance structures. Following are the components of the planned demolition of the single-family residences and associated outbuildings: Structural Demolition: Following any required regulated/hazardous materials abatement the structures will be removed in total, including shallow foundations, and basements at two properties (Parcels 3 and 5). Septic/Sanitary Sewer: All parcels are serviced by septic systems with limited information available on configuration. No sewer service exists at the subject properties with the exception of a branch sanitary sewer line at Parcel 14 that is not connected to any on-site structures and runs southward to service at Chelan Place NE. The project will not impact the branch line on Parcel 14. Septic tanks: Will be pumped, removed and the void filled with gravel. No septic tanks are located within a mapped wetland. Septic tanks located within the wetland buffer zones are all in landscaped lawns adjacent to the residence. Tank removal will have no impact on a mapped wetland and will require no removal of native vegetation within a wetland buffer. City of Renton Permitting Project Narrative – Chelan Ave NE Residential Demo Phase 1 February 7, 2020 Page 3 40245.009 Natural Gas: All natural gas service will be disconnected via PSE with service piping to be cut and capped within 36” of property lines. The gas line at parcel #9 is located partially within the Wetland B buffer zone. This line will be removed with the city’s permission or left in place within the wetland buffer. No other underground utilities to be removed exist in wetlands or buffer zones. Water: All water service will be disconnected, and meters removed, with service piping to be cut and capped within 36” of property lines. Power/Telecom: All electrical and telecom service will be disconnected and coiled at existing power poles, which are to remain pending future development. Earthwork: No substantial earthwork is included in the proposed demolition project scope with the exception of backfilling of basements, septic tanks, and contouring at former structure footprints to achieve proper surface runoff control. Stabilization: Disturbed soils will be temporarily stabilized in compliance with NDPES General Permit and City of Renton wet/dry weather code requirements. Permanent stabilization will be attained through application of fine compost and hydroseeding using City of Renton approved seed mixes. Wetland Buffer Protection: Certain structures and improvements to be removed exist within wetland buffer zones. The project will include installation of wetland buffer protections at the buffer zone boundaries and will be installed as close as feasible to structures/improvements to be removed from within the buffer zones. Wetland Buffer Protection will include high-visibility construction and silt fencing and posted signage as detailed on the project plans based on City of Renton standard details. No activity will occur within the mapped wetlands. Construction Entrances: Contractor will utilize either standard stabilized construction entrances per COR standard detail or existing driveways with track out control mats or rumble plates as construction entrances at each residence. Construction Stormwater Management: Construction stormwater will generally be managed through on-site retention/infiltration given the predominance of vegetated pervious surfaces at the subject properties. High- visibility silt fence will be utilized to prevent surface runoff from impacting mapped wetlands. Ground disturbance at each parcel will be of short duration (1-3 days) and will include temporary stabilization as needed prior to permanent stabilization. Schedule: Current project scheduling includes permitting and solicitation of bids through mid-late February 2020, with contract award and notice to proceed anticipated in early March, and construction lasting through early May. Attachment(s) – via upload: Chelan Ave NE Residential Demolition Draft Contract Drawings, PBS, 12/12/19 Wetland Delineation Report, The Watershed Company, Inc., 9/30/19 ALTSA/NSPS Land Title Survey, Terrane, 10/12/19 Tree Inventory, Terrane, 10/12/19 cc: Matt Feldmeyer, RSD