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HomeMy WebLinkAboutWPO200800104 Review Comments Erosion Control Plan 2009-08-05pF AL �'IRGINZP COUNTY OF ALBEMARLE Department of Community Development 401 McIntire Road Charlottesville, Virginia 22902 -4596 Phone (434) 296 -5832 Fax (434) 972 -4126 Project: Plan preparer: Owner or rep.: Date received: Rev. 1: Rev. 2: Rev. 3: Date of Comment: Rev. 1: Rev. 2: Rev. 3: Engineer: WPO- 2008 - 00104, Emmanuel Episcopal Church Mr. Mark Lieberth; Land Planning & Design mark @lpda.net Emmanuel Episcopal Church; Theodore Caplow, George W Ellinger & Elizabeth Pinkerton Scott 7 November 2008 3 February 2009 19 May 2009 21 July 2009 22 December 2008 25 February 2009 29 June 2009 5 August 2009 John P. Diez /Amy Pflaum - Current Development Engineering The Water Protection Ordinance application for Emmanuel Episcopal Church, received on July 21, 2009, has been reviewed. A. General Review Comments 1. Please provide a scale and North arrow for the vicinity map. (Rev. 1) Comment has been addressed 2. Please submit culvert calculations for the 15" culvert under the entrance road. (Rev. 2) Comment has not been addressed. (Rev. 3) Comment has been addressed 3. Please submit culvert calculations for the culvert under Rt. 250. (Rev. 1) Comment has been addressed 4. Please remove all notated revisions prior to final plan submittal. (Rev. 3) Comment has been addressed B. ESC Plan Review Comments 5. The limits of disturbance are unclear. Please provide limits of disturbance with a thicker line to help highlight its perimeters. (Rev. 1) Comment has been addressed 6. The drainage divides to the sediment traps are unclear. Please provide drainage divides for all drainage areas to proposed facilities as used in the computations. (Rev. 1) Comment has been addressed 7. The plans state that the construction entrance will drain to Sediment Trap "A ". We suggest that the entrance be drained to Sediment Trap "B" since it is much closer than ST -A, there is concern that the runoff will not reach ST -A. (Rev. 1) Comment has been addressed 8. Please indicate where church visitors will be parking during the time of construction. Also, demonstrate the circulation for the construction vehicles. (Rev. I) Comment has been addressed 9. There appears to be a pipe in ST -A. Please refer to the Virginia Erosion & Sediment Control Handbook method for design of sediment traps. (Rev. I) Comment has been addressed. 10. The diversion dike on the south side of the construction entrance should be extended 40' to 45' to the West to assure sediment -laden runoff from the construction entrance is directed to the trap. (Rev. I) Comment has been addressed 11. It appears that the 12" pipe needs outlet protection. (Rev. 2) Comment has been addressed. 12. Please include calculations and details for the sediment traps. Please locate the sediment traps on the plans. (Rev. I) Comment has been addressed. 13. Please provide tree protection to all trees that wish to be preserved. (Rev. 2) Comment has been addressed. C. SWM Plan Review Comments 14. Please provide copies of manufacturer's approval of the plan for any manufactured stormwater management facilities (raintanks). (Rev. 2) Please discard this comment due to a change in the design. 15. Please show all proposed stormwater management easements, dimensioned and labeled. (Rev. 2) Comment has been addressed. 16. Please show 12" PVC pipe draining into IT -2 in the profile view. (Rev. 2) Please discard this comment due to a change in the design. However all pipes have been profiled. 17. Please revise BMP calculations for the impervious areas. Calculations do not match those on the drainage area maps. (Rev. 2) Comment has been addressed. 18. Detention calculation for water quantity does not show any calculations for an outlet. Please provide outlet calculations for water quantity. (Rev. 2) Comment has been addressed. 19. Outlets need to be shown on the stormwater management plans and details. (Rev. 2) Comment has been addressed. 20. The removal rates listed for each drainage area seem low. Please include the impervious area and removal rate calculations in your submittal. (Rev. I) Comment has been addressed 21. The "rip -rap channel" being proposed by the existing septic tank in Stormwater Area IT -1 appears to be in the wrong location. It would make more sense to move it to the corner of the proposed parking lot where water that has collected in the curb will be released. The rip -rap could direct this water to the infiltration trench. (Rev. 2) Comment has not been addressed. Parking lot curb (732.12 BC) will release water onto the slope rather than direct it to the bio-filter. (Rev. 3) Comment has been addressed 22. The Detention Compliance table states that IT -1 & IT -2 are designed to store the entire 10 -yr post development run -off volume. Please provide further detail so that this statement can be verified. Run -off calculations were not submitted for IT -3 and IT -4. (Rev. 2) Please discard this comment due to a change in the design. 23. Please provide sizing calculations for the proposed 12" storm drain. What type of inlet is proposed? This pipe needs a standard end section. (Rev. 2) Comment has been addressed 24. Per VSMH 3.1OB: Soil percolation rates should be based on actual subsurface analysis and permeability tests. Only estimates have been provided. (Rev. 2) Please discard this comment due to a change in the design. 25. Sheet flow will not be captured by the road in the west side in drainage area "A ". In order to capture flow, curb must be extended or a berm must be provided. (Rev. 3) Comment has been addressed 26. Please provide a trash rack for the 6" orifice in the detention pond. (Rev. 3) Comment has been addressed 27. The issue of the adequate channel for the detention pond discharge was discussed during our last meeting. A cursory analysis to include photographs and a field description of this outfall were requested. This was not received with this submittal package. (Rev. 3) Comment has been addressed The Erosion & Sediment Control and Stormwater Management Plans (WP0200800104) submitted 21 July 2009 have received Engineering Review and meet Albemarle County minimum checklist items for approval. Please submit 5 paper copies (if all in one set, 4 E &SC and 4 SWM if separate) of the Plan to Current Development Engineering. A completed copy of the Standard Stormwater Maintenance Agreement and fee for recordation for the stormwater facilities is required for TMP 70 -12 prior to final approval j17 -304E] The forms and instructions can be found on the Community Development Department Web site on www.albemarle.oriz. You may contact Pam Shifflett (Albemarle County Department of Community Development) at ext. 3246 for further information on bonding procedures and Maintenance Agreements. \\ Cob- dts01 \cityviewlnk\Docs \2008 \WPO \WPO200800104 - Emmanuel Episcopal Church\E4_esc swm_JPD_08 -104 Emmanuel Episcopal Church.doc