7301 HARDESON RD 2019-01-11 - Laserfiche WebLink

44-rpo. PUBLIC WORKS -71.3 or within reasonable access to the site and shall be transferred with the property to the new owner. Refer to the above-referenced section of the SWMM for additional detailed requirements. o Include reference to the 2013 Guidance Document: Western Washington Low Impact Development Operation and Maintenance developed by Washington State Department of Ecology for LID facilities added to satisfy MR#5, as appropriate based on above comments. o Provide the latest available O&M requirements and guidance by the manufacturer of the selected water quality treatment BMP. • Conveyance System Design o Document the conveyance design standards that were used as the basis of design in the Drainage Report. o Provide sizing calculations performed, including narrative discussion of methods, assumptions, and results and model or spreadsheet output. Also include discussion of the hydraulic grade line through the water quality treatment facilities and infiltration pond for the design storms of interest for flow control and water quality treatment sizing. o Document whether the pipe sizes, slopes, and velocities are in accordance with 4-2.3(2) Pipe Sizes, Slopes, and Velocities of the DCSS. 0 2. Additional Comments on Design Drawings: • Sheet C-06 o Update Note E in the City of Everett Storm Drain Notes to reflect the actual project requirement for stenciling or stamping the catch basin grates. o Show proposed topographic contours. o Show pipe length, diameter, and slope for discharge pipe from CB-15. See related comment on Sheet C-09. • Sheet C-09 o Provide inlet protection for storm drain inlets on Hardeson Road that may be impacted by slope runoff. o Infiltration ponds should not be used as a temporary sediment pond/trap as the collected sediment will reduce the long term infiltration rates. Recognizing that this is an existing pond it may be feasible to use it for temporary sediment collection,but provisions need to be made to be made to ensure the infiltration capacity of the pond bottom soils. Either way provisions need to be shown on the plan to ensure that the pond is protected during construction. See SWPPP element#13. o Update pond sizing as needed based on infiltration feasibility and design assessment and other updates needed to comply with the SWMM. Refer to above comment in the MR#5 section regarding use of an appropriate pre- developed land use condition. Also refer to the below comment in the Sheet--. (j'age 8 of 9. -'