1800 41ST ST 2023-06-23 - Laserfiche WebLink

CSWPPP ANALYSIS& DESIGN This section, along with the Temporary Erosion and Sediment Control (TESC) Plan contained in the engineering drawings, is intended to serve as the construction Stormwater Pollution Prevention Plan (SWPPP)for the project. The SWPPP is outlined in conformance with the 2005 edition of the Washington State Department of Ecology's Stormwater Management Manual for Western Washington (DOE Manual). 1.0 —INTRODUCTION An introductory overview of the project has been provided in the Executive Summary of this report. 2.0 —SITE DESCRIPTION A general site description has been provided in the Executive Summary of this report. Additional detailed information is provided through the rest of this report. 3.0 —CONSTRUCTION STORMWATER BMPs 3.1 —12 BMP ELEMENTS Element#1—Mark Clearing Limits To protect adjacent properties and to reduce the area of soil exposed to construction,the limits of construction will be clearly marked before land-disturbing activities begin. Trees that are to be preserved, as well as all sensitive areas and their buffers, shall be clearly delineated, both in the field and on the plans. In general, natural vegetation and native topsoil shall be retained in an undisturbed state to the maximum extent possible. The BMPs relevant to marking the clearing limits are identified in Appendix 2B. Alternate BMPs for marking clearing limits are included in Appendix 2C as a quick reference tool for the onsite inspector in the event the primary BMP(s)are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit(Appendix 2D). To avoid potential erosion and sediment control issues that may cause a violation of the NPDES Construction Stormwater permit,the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs after the first sign that existing BMPs are ineffective or failing. Element#2—Establish Construction Access Construction access or activities occurring on unpaved areas shall be minimized, yet where necessary, access points shall be stabilized to minimize the tracking of sediment onto public roads, and wheel washing, street sweeping, and street cleaning shall be employed to prevent sediment from entering state waters. All wash wastewater shall be controlled on site. The specific BMPs related to establishing construction access that will be used on this project are identified in Appendix 2B. Alternate construction access BMPs are included in Appendix 2C quick reference tool PP as a for the onsite inspector in the event the primary BMP(s)are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NPDES Permit(Appendix 2D). To avoid potential erosion and sediment control issues that may cause a violation of the NPDES Construction Stormwater permit,the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of one or more of the alternative BMPs after the first sign that existing BMPs are ineffective or failing. 1800 41st Street—Parking Expansion Drainage Report I