HomeMy WebLinkAboutWPO201500042 Approval - County 2015-11-18�pF A
COUNTY 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. 2/3)
Date of comments:
(Rev. 1)
(Rev. 2/3)
Reviewer:
VSMP Permit plan (Amendment) review
Old Trail Village Block 27 —WPO Amendment
Chris Mulligan, Bill Ledbetter, Raleigh Davis — Roudabush, Gale & Assoc, Inc
914 Monticello Road, Charlottesville, VA 22902, cmulligan(a),roudabush.com,
bledbetter(e)roudabush.com, rdavis a,roudabush.com
March Mountain Properties LLC [1005 Heathercroft Circle, Suite 100]
Dave Brockman, dave(aoldtrailvilla eg com
6 Jul 2015
1 Oct 2015
13 Nov; 18 Nov 2015
28 Jul 2015
2 Nov 2015
17 Nov; 18 Nov 2015 improved
John Anderson
All comments addressed with this or prior plan revisions.
A. Stormwater Pollution Prevention Plan (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. Registration Statement submitted with block 27 is identical with the registration statement submitted to
DEQ last spring (7 -May 2014). It is not immediately clear whether a registration statement is required,
since this block is covered under VAR100043. Reviewer has left message with DEQ to advise on question
of registration statement requirements for this (and future) block/s. In any case, please leave registration
item #2 blank. (Rev. 1) Addressed.
2. Once WP0201400042 is approved, update SWPPP to include Approved block 27 ESCP and SWMP.
(Rev. 1) Addressed.
3. TMDL: Update SWPPP to reflect DEQ, p. -1, 15- Aug -14 VPDES CGP coverage letter (VAR100043):
DEQ staff has determined that the proposed land- disturbing activity will discharge to a surface water identified
as impaired or for which a TMDL wasteload allocation has been established and approved prior to the term of the
general permit for (i) sediment or a sediment - related parameter or (ii) nutrients. Therefore, the following general
permit (Part 1.B.4) and SWPPP requirements (Part II.A.5) must be implemented for the land- disturbing activity,
• Permanent or temporary soil stabilization shall be applied to denuded areas within seven (7) days after
final grade is reached on any portion of the site;
• Nutrients (e.g., fertilizers) shall be applied in accordance with manufacturer's recommendations or an
approved nutrient management plan and shall not be applied during rainfall events;
• Inspections shall be conducted at a frequency of (i) at least once every four (4) business days or (€i) at
least once every (5) business days and no later than 48 hours following a measurable storm event. In the
event that a measurable storm event occurs when there are more than 48 hours between business days,
the inspection shall be conducted on the next business day; and
• Representative inspections used by utility line installation, pipeline construction, or other similar linear
construction activities shall inspect all outfalls.
(Rev. 1) Addressed.
Engineering Review Comments
Page 2 of 4
Alb. County recommends Applicant/Permittee periodically review and update VAR 100043 SWPPP. (Rev.
1) Acknowledged.
B. VSMP: SWPPP: Stormwater Management Plan (WPO201500042) — AmENDiv1ENT TO WPO201400004
VSMP Regulation 9VAC25- 870 -108 requires the VSMP authority to approve or disapprove a SWMP. This plan is
W12roved.
1. WPO201400004 indicates water quality /quantity compliance —TITLE SHEET statement to this effect may
be helpful. (Rev. 1) Addressed.
2. Review ISP comments, SDP201500015, 20 -May 2015, items 8, 9, 12, 13, 15, 17, 21. Revise accordingly.
Also, RP comments, item #4 (SUB201500123). (Rev. 1) Addressed.
3. RP comment #4: Critical: Sheets 4, 6, 9 (Utility plan, Grading plan, Storm profile: Ex. #144 4230 (outfall))
reflect a post - construction stabilized condition by proposing removal of Ex. Sediment basin. This is
problematic. There is possibility future development of blocks 7, 6, 26, or 35 will require trap/basin in
similar location (sheets 3, 9, 10). Construction of structures between inlet #223 and UBP (outfall) is
contingent upon complete upslope stabilization of all areas/blocks draining to Sir. #223 to ensure negligible
sediment -laden runoff reaches Str. #223. Sir. #223 makes direct connection with UBP, an aesthetic amenity
that provides habitat and quality /quantity Mgmt. (4 X WQV) for 43± on- site /110± off -site Ac. (sheets 9, 10;
WPO201400004).
Revise site, road, and VSMP plans using notes, labels, details, and sequence to state that until all upslope
areas requiring ESC control are stabilized ([control] via Ex. Sediment basin approved under
WPO201400004 /proposed to be modified under WPO201500042), only pipe #223A may be shown as an
outfall from Str. #223 (sheet 3). Str. #223A is proposed to replace Ex. Str. 156A.
Note: This topic was discussed in detail in email (J. Anderson, 5/21/2015 6:46 AM) and Initial Site Plan
comments, SDP201500015, 20 -May 2015, items 8, 9, 12, 13, 15, 17, 21. There is no discernible response
to ISP comments on this point.
Please review ISP comments (SDP201500015) and 5/21/2015 email, and revise VSMP /WPO plan
accordingly. Please call if any questions. (Rev. 1) Addressed via redesign. As follow-up, please include
language from RGA comment response letter in Note, sheets 4, 8. Please revise Notes to read [sheet 4/8]:
"Str. #229 will not be built until all upslope areas draining to Str. #228 are stabilized, and the Ex. Sediment
Basin is removed, per County Inspector approval. These upslope areas include all of the contributing runoff
from block 27 and future blocks 7, 6, 26 and 35." Also: SHEET 3: Please remove /delete note that reads:
"Upon site stabilization, install permanent outfall into Upper Ballard Pond (Str. #229 - #230) & remove
temp. pipe Str#231 and Str#232." This note may be misconstrued. (Rev. 3) Addressed.
4. Reconcile storm sewer profile Ex. #144 - #230 (outfall) with plan view. In profile view, please revise to
show riprap outfall protection above rather than below Upper Ballard Pond Normal WSE = 672.60' —and
ending at water's edge. (Rev. 1) Addressed.
5. Ref. Final Site Plan comments, SDP201500035. Revise design accordingly. (Rev. 1) Addressed.
C. VSMP: SWPPP: Erosion Control Plan (WPO201500042)
Virginia Code §62.1- 44.15:55 requires the VESCP authority to approve or disapprove an ESOP. This plan is approve d.
L Copy profile, Ex. Sediment basin, from WPO201400004 to this plan (pa-14ial i"'^^°, belOIA). (Rev. 1)
Addressed.
Engineering Review Comments
Page 3 of 4
2. Provide plan/profile of proposed modified Ex. Sediment basin, similar to images bele (unrelated project)
[Rev. 3 /images deleted]. (Rev. 1) Not Addressed, as requested. Please ref. images below. Also, please
ref. email 10/28/2015 4:39 AM — Email requests design "ensure profile views are drawn with horizontal
compression not more than 4X vertical scale: for example, if 1" =5' vert, then 1" =20' horizontal, Max."
Plans submitted 1 -Oct cannot reflect 28 -Oct email request, but revisions do not respond to comment
request. Please revise modified sediment basin profile, as requested. (Rev. 2) Addressed.
3. Recommend additional contour labels. (Rev. 1) Addressed.
4. Sheet 5 — Provide yard inlet /s in open space to protect dwellings against peak storm runoff events. (Rev. 1)
Addressed.
5. Sheet 7 — Revise text:
a. Project Description: Although the existing sediment basin was "sized to accommodate all of the
western area development," it is proposed to be modified, and then removed in Phase II. This
circumstance is addressed at length in RP comments. Revise narrative description to at least be
consistent with Sequence of Construction Item #3 (Ex. Basin to be regraded). Consider effect of
basin regrading. (Rev. 1) Addressed.
b. Sequence of Construction
i. RGA/PE and contractor shall verify functionality of existing sediment basin. (Rev. 1)
Addressed.
ii. Revise item #3 consistent with plan sheet 3, which states Str. #156A will be replaced, not
extended. Plan view shows replacement, not extension. Also, #165A, typo. (Rev. 1)
Addressed. As follow -up, seq.constr.note #4: please insert this statement between
sentences 1 and 2: "Remove existing temporary storm pipe (Str. #156A) and outfall (see
sheet 3)." Also, please edit seq.cosntr.note #4, sentence 2, to read: "Re -grade the existing
sediment basin and install the proposed storm sewer system (pipe Str. #226 -MH Str. #228)
and the..." (Rev. 3) Addressed.
iii. Revise sequence item #7 to read "Upon site stabilization of all upslope areas, including
future blocks, draining to Str. #223, install permanent outfall into Upper Ballard Pond."
(Rev. 1) Addressed.
iv. Move revised item #7 to later point in sequence of construction. (Rev. 1) Addressed.
v. Revise item #8 to read: "Permanent soil stabilization shall be applied to all denuded areas
within seven days after final grade is reached on any portion of the site. Temporary soil
stabilization shall be..." (Rev. 1) Addressed.
vi. Include description of ESC measures designed to prevent impact to UBP during
installation of outfall to UBP. (Rev. 1) Addressed.
c. Calculations — Revise text. No water quality calculations are included or required with application.
(WPO201400004 indicates water quality compliance statement to this effect may be helpful.)
(Rev. 1) Addressed.
6. Sheet 7 — Remove inlet schedule. Remove storm sewer schedule. (Rev. 1) Addressed.
7. Provide data for proposed modified Ex. Sediment basin, similar to data in eha-Ft table be! [Rev. 3 /chart
deleted]: (Rev. 1) Not Addressed. There is value in collecting and organizing design information. The
proposed modified existing sediment basin does not have an emergency spillway. The 25 -yr WSE — 681.00.
This elevation is 11.73' higher than the pipe invert beneath Old Trail Drive, is either 4.25' or 1.15' higher
than top of riser (two riser top elevations listed), and is approx. 4.1' above crown of 42" temporary storm
pipe leading to the sediment basin. Please provide organized tabular information as requested. Please
revise riser top elevation. (Rev. 2) Addressed.
8. Future block 7 development has been discussed with County Engineer. Please anticipate trap or basin
measures with future block 7, with ESC measures located outside buffers, without runoff release to storm
inlets /pipes, with emergency spillway or weir (trap) that releases peak runoff event at non - erosive velocity
at a point at least 100' from UBP. (Rev. 1) Applicant response, 29 -Sep, 2015: "We will consider the
future Block 7 development and ESC measures that will need to be associated with it."
Engineering Review Comments
Page 4 of 4
D. VSMP: Mitigation Plan
The mitigation plan requirements can be found in County Code section 17 -406.
Sheet 3 —Label stream buffer, Upper Ballard Pond. (Rev. 1) Addressed.
Show, calculate, and propose Mitigation for stream buffer impact associated with outfall constr. to UBP.
(Rev. 1) Addressed.
Provide mitigation at 2:1 ratio. (Rev. 1) Addressed.
Process:
After approval, plans will need to be bonded. The bonding process is begun by submitting a bond estimate request
form and fee to the Department of Community Development [check VESCP bond block only -$0 fee]. One of the plan
reviewers will prepare ESC plan bond estimate and check parcel and easement information based on the approved
plans. The County's Management Analyst will prepare bond agreement forms, which will need to be completed by
the owner and submitted along with cash, certificates or sureties for the amounts specified. The agreements will
need to be approved and signed by the County Attorney and County Engineer. This may take 2 -4 weeks to obtain all
the correct signatures and forms.
Stormwater Management Facilities Maintenance Agreement is in place for Upper Ballard Pond, which provides
SWM for Old Trail Village, block 27.
After bonding is complete, the County can hold a pre - construction conference. Applicants will need to request a pre -
construction conference by completing a form, and pay the remainder of the application fee [please contact Todd
Shifflett with fee questions — 434.296 -5832 — 0072]. The form identifies the contractor and responsible land disturber,
and the fee remaining to be paid. This will be checked by county staff, and upon approval, a pre - construction
conference will be scheduled with the County inspector. At the pre - construction conference, should everything
proceed satisfactorily, a joint VSMP and grading permit will be issued by the County so that work may begin.
County forms can be found on the county website forms center under engineering;
htW: / /www.albemarle.or /g deptforms .asp ?department--cdengMTo
Thank you - 434.296 -5832 —x3069
File: WP0201500042 Old Trail -block 27 110215rev2,3 111815Approv