HomeMy WebLinkAboutWPO200800104 Review Comments Erosion Control Plan 2009-06-29pF 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:
7 November 2008
Rev. 1:
3 February 2009
Rev. 2:
19 May 2009
Date of Comment:
22 December 2008
Rev. 1:
25 February 2009
Rev. 2:
29 June 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.
(Rev. 2) Comment has not been addressed.
3. Please submit culvert calculations for the culvert under Rt. 250.
(Rev. I) Comment has been addressed
4. Please remove all notated revisions prior to final plan submittal.
B. ESC Plan Review Comments
5. 1 ne nmiLs of disturbance are unclear. Please provide limits of disturbance with a thicker line to
help highlight its perimeters.
(Rev. I) 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. I) 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. I) 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. 1) 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. 1) 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. 1) 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. 1) 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.
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.
26. Please provide a trash rack for the 6" orifice in the detention pond.
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.
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.
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