HomeMy WebLinkAboutWPO201600009 Review Comments WPO VSMP 2018-07-05COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road, Room 227
Charlottesville, Virginia 22902-4596
Phone (434) 296-5832 Fax (434) 972-4126
VSMP Plan review Amendment
Project: Old Trail Village Blocks 10, 16, 17, 18 & 30 —SWM Plan Amendment
Plan preparer: Jimmy Taggart, PE; Bill Ledbetter —Roudabush, Gale & Associates, Inc.
[BLedbettergroudabush.com; JTaggartgroudabush.com ]
914 Monticello Road, Charlottesville, VA 22902
Owner or rep.: March Mountain Properties LLC [1005 Heathercroft Circle, Suite 1001
Dave Brockman, dave a,oldtrailvilla eg com
Received date: 21 May 2018
Date of comments: 5 Jul 2018
Reviewer: John Anderson
SWPPP, ESOP, Mitigation Plans not reviewed with this correspondence —NA (SWM Plan Amendment)
WP0201600009 —Amendment to SWM Facility L-3
(Also see Stantec Stormwater Management Design Summary —East Side, Old Trail Village, Rev. 6/27/16 /pe. 4.5:
Quantity Compliance Summary. Also, p. 10 of .PDF Attached to this correspondence: Water Quantity Compliance
Summary Table, Node ID L_3, showing Q2, Qio pre -development =4.71 and 14.32 cfs, respectively.)
A. Stormwater Pollution Prevention Plan (SWPPP) —NA
B. VSMP: SWPPP: Stormwater Management Plan (WP0201600009)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP.
This plan is disapproved; please see comments below. The stormwater management plan content
requirements can be found in County Code section 17-403.
1. Water Quantity requirements are met: Q2, Qto pre -development =4.71 and 14.32 cfs, respectively*
while Q2, Qio proposed peak developed discharge =1.97 and 11.91 cfs, respectively.
* Ref. Stantec Report, rev. 6/27/16, Table 1 p. 4.5 (Also, p. 5 of Attached 6/19/16 SWMP review comments)
2. Water Quality Compliance is met* since the approved bioretention basin and proposed extended
detention -enhanced SWM facilities are equivalent at phosphorus removal efficiency.
9VAC25-870-96; Link: htts://Iis.vir inia. ov/c i-bin/le 604.exe?000+re +9VAC25-870-96
Bioretention basin 50%
Bioretention filter 50%
Extended detention -enhanced 50% 35-66%
Retention basin II (4 x WQ Vol) 50%
Infiltration (1 x WQ Vol) 50%
*pending additional design review
3. Please provide additional (enhanced extended detention) SWM facility detail, including details at
least comparable to VSWMH Vol. 1, Min. Std. 3.07, Fig. 3.07-1a and Fig 3.07-1b* and Fig. 12,
Engineering Review Comments
Page 2 of 2
Stantec Stormwater Master Plan, Old Trail Village, approved April 25, 2016. Level of detail
provided on sheets 4 and 5 is insufficient to guide review, construction, or inspection. Please see
Attached (Fig. 12). Also, note level of detail provided with Sheet 10, L-3 Bioretention Grading
and Layout, Stantec, 5/20/16, included as plan sheet 3 with this submittal. Please reference
Stantec (5/20/16) plan and profile (L_3) for appropriate level of design detail.
* Link NSWMH: https://www.deq.vir ig nia.gov/Portals/0/DEQ/Water/Publications/HndbkVolumeI.pdf
4. Minor:
a. Riser LoR elevation, sheet 4 (Outlet #1 /Routing), 636.22 does not match sheet 5 profile.
Please reconcile.
b. Sheet 2 and 4, 201.15' 36" RCP is inconsistent with sheet 5 A -built, HDPE. Please
reconcile.
5. With additional design detail for enhanced extended detention, additional comments are possible.
Note:.PDF preview welcome, prior to print submittal; reviewer out -of -office: Aue3 —Au 2g_0.
C. VSMP: SWPPP: Erosion Control Plan (WP02016-00009) —NA
D. Mitigation Plan (WP02016-00009) NA
Engineering plan review staff are available from 2-4 PM on Thursdays, should you require a meeting to discuss this
review.
Process:
Please call to discuss bonding —in interest of sending comments, have not evaluated relative expense of change in
Approved BMP. Albemarle will check on this, and Applicant may also want to review previously -approved and
bonded SWM facility L-3 to avoid unnecessary or avoidable bond expense, should an enhanced extended detention
pond bond amount be less than original SWM facility L-3 bond amount.
County forms can be found on the county website forms center under engineering;
http://www.albemarle.org/deptfonns.asp?department=cdeng)Wo
Please feel free to call if any questions.
Thank you 434.872-4501 —x3069
WP0201600009 OTV blocks 10, 16, 17, 18 VSMP Amendment 070518