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HomeMy WebLinkAboutWPO201300010 Review Comments Erosion Control Plan 2013-02-26�pF A vt�r�1Q COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road, Room 227 Charlottesville, Virginia 22902 -4596 Phone (434) 296 -5832 Fax (434) 972 -4126 Project: Seminole Trail Fire Station Plan preparer: DJG Inc [fax 757- 253 -2319] Owner or rep.: County of Albemarle [434- 872 -4501 ] Plan received date: 4 Feb 2013 Date of comments: 25 Feb 2013 Reviewer: Michelle Roberge A. Erosion Control Plan (WP0201300010) 1. Sheet C -101, which combines the three phases of the demo plan and E &S plan, is difficult to follow. I recommend providing in -sets within the sheet to clearly show the limits of disturbance, demo, and erosion control measures within each phase. For example, the drainage inlets are showing to be removed, but it also shows inlet protection. 2. Please show one construction entrance for all phases. Please use our detail found in the Albemarle County Design Standards Manual. http: / /www.albemarle.or /g_ department. asp ?department= cdd &relpa2e =13525 3. It appears the note 3.1 on C -101 regarding the replacement of drainage inlets and pipes will be done in phase II, yet the plans show it will be completed in phases II and III. Clearly show the replacement of pipes and structures in one phase with the adequate erosion control measure. Also add a note in the construction sequence to show how fire trucks can access the bay area while the pipe trenches are being constructed and stabilized, if this bay area is constructed in a different phase. 4. While phase II is in construction, please show how pedestrians parked in the existing parking lot can safely walk to the building. 5. The areas of Berkmar Drive being demolished does not match the areas of new pavement. Please match the areas to be demolished to the areas of new pavement. 6. The stockpile location is outside your proposed limits of disturbance. Please provide a temporary easement or a letter of permission for that property. If this is a marsh area, it may be difficult to bring vehicles in and out. Also, it appears the route from the stockpile to the site is along Berkmar Drive. Please address how you will prevent sediment from entering Berkmar Drive. 7. It appears that part of Berkmar Drive will also be disturbed. A permit from VDOT is required to work on the ROW. 8. Please provide tree protection for oak trees north of site and south of parking lot. 9. Please show dust control, temporary seeding and permanent seeding symbols on sheet C -101. B. Stormwater Management Plan (WP0201300010) 1. Per section 4.12.15 b), parking area grading and drainage systems shall be designed and constructed to minimize, to the greatest extent practical, the amount of surface runoff exiting or entering through entrances to public streets. It appears that both access roads will drain to a public street. Minimize the amount of runoff entering the public streets by placing additional inlets at west side of access roads. Revise the grading. See additional comments below that will impact grading of access road. Engineering Review Comments Page 2 of 2 2. Per section 4.12.17 a), vehicle access aisles that are not adjacent to parking spaces, shall not exceed a grade of ten (10) percent. It will be difficult to achieve this, but 12% is a reasonable alternative. Please request the waiver in writing and provide all information necessary to justify that no reasonable design alternative exists. 3. Per section 4.12.17 b), an adequate landing and /or grade transition shall be provided for vehicle access aisles at the intersection with public streets or private roads to allow for the stopping of vehicles and sight distance... As a guideline, the approach grade should not exceed four (4) percent for a distance of not less than forty (40) feet measured from the edge of the street or road being intersected. This is difficult to achieve but designing a vertical curve will provide an adequate landing and a low spot for runoff to drain into additional inlets reffered to in comment 1. 4. YD -1 is shown on grade. I recommend changing the contours slighty to show sump conditions. 5. Please provide a bumper block for the handicap parking adjacent to the sidewalk. Concrete blocks are required for parking stalls with a sidewalk less than 6'. Show the curb and gutter for this parking stall with a handicap ramp in the unloading area. Also show spot elevations for corners of sidewalk to avoid runoff north of site. 6. Please provide the outlet protection calculations. 7. Please provide the manufacturer's certification and approval for your proposed Filterra design. 8. Also provide the removal rate computation found on our website to meet the water quality criteria. hlt2://www.albemarle.ora/deptfonns.asp?department--cdenamTo 9. Please provide the manufacturer's certification and approval for your proposed cistern. 10. Please show the stormdrain profile for YD -1 to outlet 2. 11. Please show the waterline crossing between DI -4 and outlet 1 on the stormdrain profile on sheet C- 503. 12. Call out the spot elevations at corners of concrete pavement abutting the south of the bldg. Also show the flow of runoff on pavement. 13. A building permit is required for retaining walls. Please refer to our Albemarle County Design Standards Manual as a guide on what is required on plans. It appears the wall elevations are staggered. Please show the bottom of wall elevations as well. 14. The access road to the parking lot is too steep where it meets Berkmar Drive. I recommend reducing the slope where it is about 20% to about 12 % -14% to smoothen out the transition between the access road and Berkmar Drive. 15. Please show how the 12" pvc pipe will connect to the roof drains. 16. What is the solid line north of site overlapping the porch with stairs? 17. Provide a min 20' drainage easements for proposed stormsewer. 18. The stair from the flag pole area to building entrance is over 1'. I recommend reducing height. 19. It appears that runoff will flow down to second landing and will pond. Please add a slight positive drainage in this landing. 20. The chart on sheet C -503 for DI -1 is showing a type VDOT DI -21, which is a typo. Please revise. Sincerely, �Irx� Michelle Roberge File: E1_ rp,esc,swm,fsp_GEB_template.doc