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HomeMy WebLinkAboutWPO201200034 Review Comments Erosion Control Plan 2012-04-10� OF AL ,. vIRGI1`IZP COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road Charlottesville, Virginia 22902 -4596 Phone (434) 296 -5832 Fax (434) 972 -4126 Project: Birdwood Golf Hole #3 Remodel ESC Plan (WPO -2012- 00034) Plan preparer: Mr. Alan Franklin, PE; Water Street Studios Owner: University of Virginia Foundation Plan received date: 21 March 2012 Date of comments: 10 April 2012 Reviewer: Phil Custer The first submittal of ESC plan for the Birdwood Golf Hole #4 Remodel (WPO- 2012 - 00034), received 21 March 2012, has been reviewed. Engineering can recommend approval to the plan after the following comments have been addressed. 1. Please provide Permanent Seeding symbols (PS) on all sediment traps. [Minimum Standard 1] 2. Please provide a note on the plan stating that if sod cannot be placed on an area 7 days after final grade has been reached, temporary or permanent seeding must be applied. [Minimum Standard 1] 3. Please provide Temporary Seeding (TS) and Permanent Seeding (PS) symbols on the soil stockpile area. [Minimum Standard 2] 4. Please provide Dust Control symbols (DC) throughout the disturbed area in the plan. 5. The maximum drainage area for Sediment Trap Culvert Inlet Protection is 3 acres. The maximum drainage area for Silt Fence Culvert Inlet Protection is 1 acre. [VESCH 3.08] If no disturbed area other than the runoff to trap 1 is directed to this pipe, no ESC measure appears to be necessary. 6. Please provide a note on the plan stating that all inlets within a drainage area for a sediment trap shall be sealed until its watershed has been stabilized. 7. Please delineate the limits of disturbance on the soil map in the narrative, draw the limits of disturbance on a soil map printed from the county's GISweb application, or include the soil boundaries on the ESC plan. 8. The construction entrance and laydown area must drain to a sediment trap. It looks as though the laydown area and construction entrance can be moved just off of the existing asphalt drive, close to its intersection with the cart path, and can drain to sediment trap 2 with a minor adjustment to the diversion dike. The contractor parking area may remain as long as it's for personal vehicles and no construction equipment enter and leave the limits of work area there. Please adjust the design and calculations for trap 2 accordingly. [VESCH 3.02] 9. The drainage area to trap 2 appears to be incorrect. It looks as though the high point of its drainage area is just southwest of Birdwood Drive. 10. Please extend the limits of disturbance line to include the soil stockpile area. 11. Please extend the diversion dike north of trap 2 to the sand trap. 12. Please provide silt fence to protect the disturbance southwest of the squash club basin or extend the trap 2 diversion dike to capture this area and adjust trap calculations and design accordingly. 13. The tee box area appears to be created almost entirely from cut and the green area seems to created mostly from fill. This will require many dump trucks hauling across the stream. The haul route is poorly protected outside of the sediment trap areas. Please relocate trap 2 and adjacent diversion closer to the stream to capture the haul route and adjust the design /calculations accordingly (use RWD when crossing the haul route). Albemarle County Community Development Engineering Review Comments Page 2 of 2 14. The construction of the tee boxes relies solely on silt fence and diversions for ESC protection. However, inconsistent with state standards, the silt fence is not placed parallel to contour lines and will receive concentrated flow, increasing the likelihood of sediment loss from a blowout. The diversions are being used as cleanwater diversions, which is also not consistent with state standards. East of the tee boxes, please replace the silt fence with diversions and provide one trap just off of the stream adjacent to the haul route. The diversion should be placed so that it picks up runoff from the haul route (use RWD when crossing the haul route). To minimize runoff to the west of the tee boxes, please provide a diversion from the 536 contour at the arrow now referencing the cleanwater diversion to the top of the knoll at 532.94 down to the new sediment trap. This diversion must remain throughout the construction process. Please provide a note on the plan stating this. If you still want to bypass cleanwater from the construction area, you must design the " cleanwater" diversion as permanent channels for the 2 and 10 year storms for erosion and capacity, respectively, provide instant stabilization (either sod or rip), and note in the plan and construction sequence that these channels are required before grading begins. The silt fence used for the area south of the cart path will be acceptable. The silt fence below the 531 tee box is also acceptable as long as the diversion above it to the new trap is maintained. 15. A grading permit cannot be issued for this project until the ESC bond is posted. Bonds will not be computed until after plan approval. To receive a bond computation, please submit a Bond Estimate Request Form to the County Engineer after the plans have been approved.