HomeMy WebLinkAboutWPO201100037 Review Comments Erosion Control Plan 2011-09-15ALg�,��
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COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road
Charlottesville, Virginia 22902 -4596
Phone (434) 296 -5832 Fax (434) 972 -4126
Project: WPO- 2011 - 00037, Glenmore -K2B ESC and SWM Plan
Plan preparer: Mr. Scott Collins, PE; Collins Engineering
Owner or rep.: Glenmore Associates L.P.
Date received: 14 June 2011
(Rev. 1) 8 August 2011
Date of Comment: 29 June 2011
(Rev. 1) 15 September 2011
Engineer: Phil Custer
The ESC plan for Glenmore -K2B, received on 8 August 2011, has been reviewed. The plan also extends
the sewer line farther east and now includes the SWM plan for the lots. The plans cannot be approved as
submitted and will require the following changes.
1. The 30 acre active construction limit will be monitored and enforced by the on -site ESC inspector
in conjunction with the County Engineer. Because of this, agreements in lieu of ESC plans will
not be accepted for lot construction. The current plan will add 3.43acres towards that 30acre limit.
(Rev.]) The current plan adds 15.03 acres to the 30 acre limit. The perimeter road plan
disturbed approximately 7 acres.
2. The existing site is mostly wooded, not open grass field as described in Existing Condition section
of the narrative.
(Rev. 1) Comment has been addressed.
3. The limits of disturbance does not match up with the construction of a portion of the sanitary
sewer line.
(Rev. 1) Comment has been addressed.
4. Silt fence must not be used across contours because it will act as a diversion. This standard is
broken adjacent to both the water and the sewer line.
(Rev. 1) Comment has been addressed.
5. Construction entrances must drain to a sediment trapping measure. [VESCH 3.02]
(Rev. 1) Comment has been addressed.
6. Please remove the silt fence from the stream.
(Rev. 1) Comment has been addressed.
7. Please provide a Utility Stream Crossing symbol at the sewer line's crossing of the intermittent
stream.
(Rev. 1) Please specify the diversion channel dimensions and lining as well as the culvert size.
8. Please detail how construction equipment will cross the intermittent stream. Please provide a
Stream Crossing symbol for this method.
(Rev. 1) Please see the previous comment.
9. Please provide Army Corps and DEQ approval of the stream work referenced in the previous two
comments.
(Rev. 1) Comment has been acknowledged by the applicant.
10. The ESC bond will be computed after the plan has been approved and the applicant has submitted
a Bond Estimate Request Form to the County Engineer.
(Rev. 1) Comment remains unchanged.
The ESC plan has been considerably changed and expanded since the first submittal. Therefore, additional
comments are necessary.
11. (Rev. 1) The diversions dikes shown on this plan must remain in place to direct runoff to the
stormwater facilities. These must be called out as diversions and designed as permanent
channels with 2-year velocity and 10 year capacity calculations.
12. (Rev. 1) Please accurately show the existing travelways west of lot 1. This set appears to show
the future alignment of Carroll Creek Drive which has not been approved or reviewed. Please
also show accurately where the existing waterline ends and where the construction of the new
line begins.
13. (Rev.]) The current plan proposes fill within the floodplain. Please pull all fill out of the
fioodplain or get a Special Use Permit.
14. (Rev. 1) The plan does not appear to address MS -19 concerns below SB -1, and SB- 21SB -3.
Please refer to page 7 of 35 of the current Design Standards Manual for what is expected for a
MS -19 analysis.
15. (Rev. 1) Please provide dewatering orifice calculations. It looks as though the orifices may be
larger than should be permitted.
16. (Rev. 1) Please show an adequate channel between lots 8 and 9 to sediment basin/biofilter 2.
17. (Rev. 1) Please show an adequate channel between lots 12 and 13 to sediment basin/biofilter 3.
18. (Rev. 1) On sheet 11, please provide a note stating that all existing biofilters must remain in
place for a long as possible and that their removal may only be authorized by a county
inspector.
The first resubmittal of this application included the SWM plan associated with final plats SUB -2011-
00083 and SUB-2011-00056. The following comments must be addressed prior to plan approval.
1. (Rev. 1) On sheet 13, please clearly show the channels behind all lots directing water to the new
stormwater facilities. These channels are imperative to this stormwater plan.
2. (Rev. 1) Please provide the county's modified simple spreadsheet for each stormwater facility.
3. (Rev. 1) Stormwater detention does not appear to be addressed with this plan. Please provide
detention calculations with the next submittal for each of the stormwater facilities. [17 -314]
4. (Rev. 1) During the 100 year storm, one foot of freeboard must be provided on all of the
stormwater facility embankments. [VSMH 3.011
5. (Rev. 1) Sheet 13 indicates that lot 6 is directed to stormwater facility 2, but it appears that the
back half of this lot, if not all of it, will not be captured because there is no diversion ditch.
6. (Rev. 1) Please see ESC comment 13.
7. (Rev. 1) Please provide a stormwater access path to biofilter 3. For all stormwater access paths
steeper than 10 1%, the path must be graveled or equivalent.
8. (Rev. 1) The risers for each facility should be designed in such a way it works for both
conditions (ESC and SWM). Right now, the plan requires the risers to be raised by 2.03ft,
2.02ft, and 234ft for basins 1, 2, and 3 which seems impractical.
9. (Rev. 1) On sheet 13, a note references a concrete spillway but all stormwater facilities do not
appear to have any spillway at all.
File: E2 esc swm PBC WPO- 2011 -00037 Glemore K2B.doc