Title 17D City-wide Standards
Chapter 17D.090 Erosion and Sediment Control
Section 17D.090.110 Minimum Plan Requirements
The following items shall be addressed on erosion and sediment control plans. As site conditions dictate, additional measures relating to erosion and sediment control, as determined by the licensed professional engineer (PE) preparing the plan, shall be addressed in order to meet the intent and purpose of this chapter and to comply with the stated performance standards in SMC 17D.090.180 . Furthermore , in order to reduce the discharge of pollutants to the maximum extent practicable, and to satisfy all known, available and reasonable methods of prevention, control and treatment requirements, Best Management Practices (BMPs) shall be consistent with the Spokane Regional Stormwa ter Manual (SRSM) and Stormwa ter Management Manual for Eastern Wa shington (SWMMEW).
Construction Sequence.
Sequence the construction in order to best minimize the potential for erosion and sediment control problems.
Clearing Limits Delineation.
Identify and delineate on the plan and in the field all clearing limits, sensitive/critical areas, buffers, trees to be preserved, and drainage courses.
Construction Access Route.
Access for construction vehicles should be limited to one route whenever possible. The access route must be stabilized to minimize the tracking of sediment onto roads.
Sediment Tapping Measures.
Design and construct sediment ponds and traps, perimeter dikes, sediment barriers, and other on-site sediment trapping BMPs as necessary prior to the start of other ground disturbing activities.
Protection of Adjacent Properties/Wa ter Bodies/Public and Private Streets.
Protect adjacent and/or downstream properties, wa ter bodies, public and private streets from erosion and sediment deposition. The intent is to keep sediment on the project site and not allow it to reach adjacent and/or downstream properties, wa ter bodies, and public and private streets. These measures shall be made functional prior to any upslope development taking place.
Apply permanent or temporary soil stabilization to denuded development site areas in conformance with the following schedule. Permanent ground disturbing activities that do not require a permit may achieve compliance with this schedule by installing and maintaining approved permanent BMPs that meet the purpose of this chapter.
Between October 1 and April 30, all denuded sites shall be provided with either temporary or permanent soil stabilization as soon as practicable, but in no case more than five days after ground-disturbing activity occurs.
Between May 1 and September 30, temporary erosion and sediment control measures to reduce dust and sediment transport shall be applied as soon as practicable, but in no case more than ten days after ground-disturbing activity occurs.
Ground cover shall be installed on any portion of a site that is denuded for more than six months. Sports fields or playgrounds surrounded by vegetative cover or permanently installed curbing are exempt from this requirement.
Temporary measures shall be maintained until permanent measures are established. As used herein, “temporary” means approved measures that are not intended to be a final or long-term resolution of compliance requirements.
Protection of Inlets.
Protect downstream inlets to drywells, catch basins, and other stormwa ter management facilities that are functioning during the course of the construction by approved sediment control measures so that sediment-laden wa ter cannot enter the inlets without first being filtered.
Increased Runoff from Construction Sites.
Consider and mitigate the effects and impacts of increased and concentrated runoff from ground disturbing activities on downstream properties, wa ter bodies, and public and private streets.
Wa shout Site for Concrete Trucks and Equipment.
Designate an on-site location of a slurry pit where concrete trucks and equipment can be wa shed out. Slurry pits shall not be located in a swa le, drainage area, stormwa ter facility, wa ter body, or in an area where a stormwa ter facility is proposed.
Material Storage/Stockpile.
Identify the location within the proposed ESC plan boundaries for storage or stockpile areas for any soil, earthen, or landscape material which is used or will be used on-site.
Cut and Fill Slopes.
Design and construct cut and fill slopes in a manner that will minimize erosion.
Stabilization of Temporary Conveyance Channels and Outlets.
Design, construct, and stabilize all temporary on-site conveyance channels to prevent erosion from the velocity of runoff from storms under developed conditions. Design, construct, and stabilize all temporary conveyance system outlets to prevent erosion of stormwa ter facilities, adjacent stream banks, slopes, and downstream reaches.
Dewa tering Construction Site.
Design dewa tering devices to discharge appropriately to sediment traps or sediment ponds.
Control of Pollutants Other than Sediment on Construction Sites.
Control all on-site pollutants (including wa ste materials and demolition debris) other than sediment in a manner that does not cause contamination of stormwa ter, groundwa ter, or aquifer.
Removal of Temporary BMPs.
Remove all temporary sediment control BMPs within thirty days after final site stabilization or after the temporary BMPs are no longer needed. Trapped sediment shall be removed from the project site or stabilized on-site. Stabilize disturbed soil areas resulting from removal of the temporary BMPs.
Maintenance and Permanent BMPs.
Maintenance of all erosion and sediment control BMPs is required during the ground-disturbing activity. A maintenance schedule for each BMP shall be included in the plan. Regular inspection and maintenance of all erosion and sediment control BMPs is required to ensure successful performance of the BMPs. Permanent BMPs shall be included on the plan to ensure that successful transition from temporary BMPs to permanent BMPs occurs
Date Passed: Monday, October 25, 2021
Effective Date: Thursday, December 2, 2021
ORD C36116 Section 7
