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

Element#5-Stabilize Soils Exposed and unworked soils shall be stabilized with the application of effective BMPs to I I I I I I I I I I I I I I prevent erosion throughout the life of the project. The specific BMPs for soil stabilization that shall be used on this project are identified in Appendix 2B. Seeding will be used on disturbed areas that have reached final grade or that will remain unworked for more than thirty days. Plastic Covering will be used on the temporary stock pile areas and elsewhere on the site as needed. Dust control will be implemented as needed,to prevent it being required all roadways and driveways to be paved will receive early application of gravel base. Alternate soil stabilization BMPs 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. The project site is located west of the Cascade Mountain Crest. As such, no soils shall remain exposed and unworked for more than 7 days during the dry season (May 1 to September 30)and 2 days during the wet season (October 1 to April 30). Regardless of the time of year, all soils shall be stabilized at the end of the shift before a holiday or weekend if needed based on weather forecasts. In general, cut and fill slopes will be stabilized as soon as possible and soil stockpiles will be temporarily covered with plastic sheeting. All stockpiled soils shall be stabilized from erosion, protected with sediment trapping measures, and where possible, be located away from storm drain inlets,waterways, and drainage channels. Element#6-Protect Slopes All cut and fill slopes will be designed, constructed, and protected in a manner than minimizes erosion. The specific BMPs that will be used to protect slopes for this project are identified in Appendix 2B. Alternate slope protection BMPs 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#7-Protect Drain Inlets All storm drain inlets and culverts made operable during construction shall be protected to prevent unfiltered or untreated water from entering the drainage conveyance system. However, the first priority is to keep all access roads clean of sediment and keep street wash water separate from entering storm drains until treatment can be provided. Storm Drain Inlet Protection (BMP C220)will be implemented for all drainage inlets and culverts that could potentially be impacted by sediment-laden runoff on and near the project site. The inlet protection measures to be applied on this project are identified in Appendix 2B. 1800 41st Street—Parking Expansion Drainage Report