HomeMy WebLinkAboutWPO200800104 Review Comments Stormwater Management Plan 2009-02-25pF 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: WPO- 2008 - 00104, Emmanuel Episcopal Church
Plan preparer: Mr. Mark Lieberth; Land Planning & Design mark @lpda.net
Owner or rep.: Emmanuel Episcopal Church; Theodore Caplow,
George W Ellinger & Elizabeth Pinkerton Scott
Date received: 3 February 2009
Date of Comment: 25 February 2009
Engineer: John P. Diez /Amy Pflaum - Current Development Engineering
The Water Protection Ordinance application for Emmanuel Episcopal Church, received on February 3,
2008, has been reviewed. The plans cannot be approved as submitted and will require the following
corrections before approval can be granted:
A. General Review Comments
1. Please provide a scale and North arrow for the vicinity map.
(Rev. I) Comment has been addressed
2. Please submit culvert calculations for the 15" culvert under the entrance road.
3. Please submit culvert calculations for the culvert under Rt. 250.
B. ESC Plan Review Comments
4. The limits of disturbance are unclear. Please provide limits of disturbance with a thicker line to
help highlight its perimeters.
(Rev. I) Comment has been addressed
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. I) Comment has been addressed
6. 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. I) Comment has been addressed
7. 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
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.
9. 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
10. It appears that the 12" pipe needs outlet protection.
11. Please include calculations and details for the sediment traps. Please locate the sediment traps on
the plans.
(Rev. I) Comment has been addressed.
12. Please provide tree protection to all trees that wished to be preserved.
C. SWM Plan Review Comments
13. Please provide copies of manufacturer's approval of the plan for any manufactured stormwater
management facilities (raintanks).
14. Please show all proposed stormwater management easements, dimensioned and labeled.
15. Please show 12" PVC pipe draining into IT -2 in the profile view.
16. Please revise BMP calculations for the impervious areas. Calculations do not match those on the
drainage area maps.
17. Detention calculation for water quantity does not show any calculations for an outlet. Please
provide outlet calculations for water quantity.
18. Outlets need to be shown on the stormwater management plans and details.
19. 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
20. 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.
21. 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.
22. Please provide sizing calculations for the proposed 12" storm drain. What type of inlet is
proposed? This pipe needs a standard end section.
23. Per VSMH 3.1O13: Soil percolation rates should be based on actual subsurface analysis and
permeability tests. Only estimates have been provided.
Once these comments have been addressed, please submit 2 copies of the revised plans, calculations, and
narratives to Current Development Engineering.
Current Development Engineering is available from 2:30 -4 PM on Thursdays to discuss these review
comments. Please contact Amy Pflaum at 434 - 296 -5832 ext. 3069 or email adpflaum @albemarle.org to
schedule an appointment.
E2_esc swm_JPD_08 -104 Emmanuel Episcopal Church