HomeMy WebLinkAboutWPO201500090 Approval - County 2016-03-31COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road, Room 227
Charlottesville, Virginia 22902-4596
Phone (434) 296-5832 Fax (434) 972-4126
Project:
Plan preparer
Owner or rep.:
Plan received date:
(Rev. 1)
(Rev. 1 rev)
(Rev. 2)
Date of comments:
(Rev. 1 rev)
(Rev. 2)
Reviewer:
VSMP Permit plan review —Approved
Glenmore Sec. K2B Ph. B, Lots 1 & 7-16 SWM Amendment Plan
Graham Murray, Collins Engineering [200 Garrett St., Suite K, Charlottesville,
VA 22902,agr ham@collins-en ing eering com, scottacollins-en ing eering com]
Glenmore Associates Limited Partnership, P.O. Box 7623
Charlottesville, VA 22906
10 Nov 2015
7 Jan 2016 [not reviewed]
3 Mar 2016*
28 Mar 2016 (.PDF/e-review)
22 Dec 2015
6 Mar 2016
31 Mar 2016 Approved
John Anderson
Collins Engineering requested review of updated revised plans / [email: 3/2/2016 11:46 AM "one minor
change on the Glenmore SWM pond WPO plans"]
A. Stormwater Pollution Prevention Plan (SWPPP) —Also, please ref. WP0201500034 SWPPP
The SWPPP content requirements can be found in County Code section 17-405. A SWPPP must contain (1)
a PPP, (2) an ESCP, (3) a SWMP, and (4) any TMDL measures necessary.
1. This plan modifies WP0201500034 SWPPP. Revise and submit SWPPP Exhibit/ESCP for
review as soon as practicable. Also, section C., below. Revise Exhibit to show relocated features
to the extent locations of concrete wash-out, dumpster, fuel storage, porta john, etc., may change.
(Rev. lrev) Addressed.
B. VSMP: SWPPP: Stormwater Management Plan (WP0201400090 /Amends WP0201500034)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. This
plan is approved.
1. This plan proposes to amend WP0201500034 to combine SWM facilities #2 & #3 approved under
WP0201500034 on 29 Jul 2015 as a larger single Part IIB Ex. Detention Facility (#2). Proposed SWM
Plan expands post -developed area of storm runoff that will be routed through this facility. Plan proposes to
capture runoff beyond Glenmore K213, Lots 1 & 7-16, to include approximately ten lots of future K2C
development.
a. Label on sheet 7 reads "/Future 62 Lot Glenmore K2C Development under review (separate set of
plans." At present, there do not appear to be any future Glenmore K2C VSMP plans under review.
Please revise label. (Rev. lrev) Addressed.
b. Assign #s to future K2C lots with SWM proposed with this Amendment Plan. It will be essential
to reference lots covered under WP0201500090 by Lot number. WP0201500090 proposes
quantity and quality treatment for these lots. (Rev. lrev) Addressed.
Engineering Review Comments
Page 2 of 3
2. Please use the VaRRM New Development spreadsheet. (Ref. 12/22/2015 10:07 AM email) (Rev. 1rev)
Addressed.
3. Please exclude Carroll Creek Road from New Development VaRRM .xls Land Cover table —that is, strip
out impervious area associated with Carroll Creek Road. (Rev. 1rev) Addressed.
Sheet 8
4. Provide SWM Facility Access turnaround at the N end, else vehicles may be required to reverse a distance
of 600'± to Carroll Creek Road. (Rev. 1 rev) Addressed.
5. Revise 2:1 Max label east of Access (where access bears SE to NW, near emergency spillway) to read 4:1
Max. (Rev. 1rev) Addressed.
6. Label floor dimensions of Ex. detention basin deep pool, micro pool, and wetland cell to aid construction
and inspection. (Rev. 1rev) Addressed. As follow-up: Please relocate wetland cell leader arrow tip to
point to 78' X 25' wetland cell. (Rev. 2) Addressed.
7. Consider alternative location for emergency spillway —the spillway lies at least in part on a fill slope.
(Rev. 1rev) Addressed/discussed w/Collins Engineering, 4 Jan 2016.
8. Confirm emergency spillway is shown to scale in plan view. Plan view L =75'±. Profile indicates <75'.
(Rev. 1rev) Addressed.
9. Label floor elevation of forebay in profile view. (Rev. 1rev) Addressed.
10. Revise berm labels to read baffle where raised contours do not isolate sections of the facility, consistent
with Spec. 15 plan view illustration on this sheet. (Rev. 1rev) Withdrawn.
11. Evaluate proposed 24" Cl. III RCP against Ex. detention basin elevations. At elevation 336'±, it appears
that detained storm runoff may exit facility via this 24" DIA pipe. Compare against 6" midflow orifice
invert Elev. =336.25'. (Rev. 1rev) Addressed.
12. Ex. detention facility profile: Above NWSE, recommend Max. slope =4:1; below NWSE, Max. slope =2:1.
(Rev. 1rev) Addressed.
13. Ex. detention F wili [Rev. Irev] Wet Pond embankment profile: show clay core/similar typical of CE
embankment designs. (Rev. Irev) Addressed. As follow-up: Clay core is shaded; label shading clay core.
Also/sheet 8: Please edit SWM Facility No. 2 Section note that reads: "Contractor shall install embankment
in accordance w/ the detail on this sheet" to include this additional text: "...and Wet Pond Construction
Notes, sheet 9."
New: Please provide saturated (zone) pipe length calc., number, dimensions, and relative location of anti -
seep collars, 30" DIA Cl. III RCP barrel, if anti -seep collars required. (Rev. 2) Addressed.
Calculations Packet
14. Post -development routing: confirm diameter or depth (in) of 6" Midflow orifice =6.000. (Rev. 1rev)
Addressed.
15. Revise hydrograph/output descriptions for interim routings (10.830 Ac.) to read Interim rather than Final
buildout. (Rev. 1rev) Addressed.
16. Revise TR -55 Worksheet 2 to reference future K2C lots by Lot number. Also, comment l.b., above.
(Rev. 1rev) Addressed.
17. Also, please ensure TR -55 Worksheet 2 includes revised descriptions sent with 12/18/2015 2:50 PM email.
(Rev. Irev) Addressed.
18. New: Recommend proposed contours to define ditch N of SWM access to help ensure Lot 9 post -developed
runoff reaches the Wet Pond. Disregard this comment if intent is for runoff to sheet across access and reach
pond via 24" culvert. [Note: Added benefit: erosion protection for facility access.] (Rev. 2) Withdrawn.
19. New: As follow-up [no revision required]: (Rev. 2) Addressed.
a. Trivial: Stormwater Management Summary references future lots 52-63; should read 52-62.
b. Trivial: Stormwater Management Notes/sheet 7, state 2.3 lb/yr may be applied to future 62 -lot
development. VRRM/full buildout indicates 8.07 lb/yr reduction required, while Drainage Area B
Summary indicates 10.35 lb/yr provided. 2.3 lb/yr may be applied to future 62 -lot development.
Engineering Review Comments
Page 3 of 3
C. VSMP: SWPPP: Erosion Control Plan (WP0201400034)
Virginia Code §62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESOP. After discussion, no
supplemental ESCP is required for this SWM Plan Amendment.
This plan requires a supplemental ESC Plan for approx. ten future Glenmore K2C lots. Prior to
submitting a VSMP plan (SWPPP, SWM, ESC) for future K2C lots not covered under this plan,
Collins Engineering should furnish a ESC plan that details measures required to develop lots that
will be covered under WP0201500090 SWM Plan. It is important that SWM and ESC for these
lots be under one WPO/VSMP Plan. An ESC Plan for future K2C lots with SWM control under
WP0201500090 is due as soon as practicable once design for future K2C lots has progressed to
the point it is possible to prepare such a plan. The ESCP will be reviewed and compared against
ordinance, VESCH 1992, and ACDSM, will be reviewed (with comments) in the normal manner.
(Rev. lrev) Addressed.
The VSMP permit application and all plans may be resubmitted as .PDF for preview approval. Once all comments
have been satisfactorily addressed, please submit 4 copies of the complete permit package with a completed
application form.
Please request SWMP bond estimate —bond associated with WP0201500034 frust should likely be replaced.
Thank you.
File: WP0201500090—Glenmore Sec. K2B Ph. B, Lots 1 & 7-16 SWM Amendment Plan-033116rev2—Approval