HomeMy WebLinkAboutWPO201500042 Review Comments WPO VSMP 2015-07-28�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
VSMP Permit plan (Amendment) review
Project: Old Trail Village Block 27 —WPO Amendment
Plan preparer: Chris Mulligan, Bill Ledbetter, Raleigh Davis — Roudabush, Gale & Assoc, Inc
914 Monticello Road, Charlottesville, VA 22902, cmulligan(a),roudabush.com,
bledbetternroudabush.com, rdavis a,roudabush.com
Owner or rep.: March Mountain Properties LLC [1005 Heathercroft Circle, Suite 100]
Dave Brockman, davegoldtrailvilla eg com
Plan received date: 6 Jul 2015
Date of comments: 28 Jul 2015
Reviewer: John Anderson
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.
2. Once WP0201400042 is approved, update SWPPP to include Approved block 27 ESCP and SWMP.
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) shad 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 (ii) 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.
4. Alb. County recommends Applicant/Permittee periodically review and update VAR] 00043 SWPPP.
B. VSMP: SWPPP: Stormwater Management Plan (WP0201500042) — AMENDMENT To WP0201400004
VSMP Regulation 9VAC25- 870 -108 requires the VSMP authority to approve or disapprove a SWMP. This plan is
disapproved. The stormwater management plan content requirements can be found in County Code section 17 -403.
Engineering Review Comments
Page 2 of 5
1. WPO201400004 indicates water quality /quantity compliance —TITLE SHEET statement to this effect may
be helpful.
2. Review ISP comments, SDP201500015, 20 -May 2015, items 8, 9, 12, 13, 15, 17, 21. Revise accordingly.
Also, RP comments, item #4 (SUB201500123).
3. RP comment #4: Critical: Sheets 4, 6, 9 (Utility plan, Grading plan, Storm profile: Ex. #144 - #230 (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 areasiblocks draining to Str. #223 to ensure negligible
sediment -laden runoff reaches Str. #223. Str. #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.
4. Reconcile storm sewer profile Ex. 4144 - #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.
5. Ref. Final Site Plan comments, SDP201500035. Revise design accordingly.
C. VSMP: SWPPP: Erosion Control Plan (WPO201500042)
Virginia Code §62.1- 44.15:55 requires the VESCP authority to approve or disapprove an ESCP. This plan is disapproved
for reasons provided in comments below. The erosion control plan content requirements can be found in County Code
section 17 -402.
Copy profile, Ex. Sediment basin, from WPO201400004 to this plan (partial image, below).
MMM
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in
m
oil
. .
. . . . . . . . . .........
Engineering Review Comments
Page 3 of 5
2. Provide plan/profile of proposed modified Ex. Sediment basin, similar to images below (unrelated project).
SEDIMENT BASIN #3 6 "70PSOIL
NTS
DUSTINGGRONNO 23" HIGH,aEGAGETEMPORARYCMP
T'OPOFDAMELEV. p64' I TRASH RACK DEVICE
'51". STORM id MIN. EMERGENCYSPYLWAY
..._. ELE1.32475f CRFSTELEV.•3,4.75
u'
RISER TOP ELEV MIN E" A, CL Ili RCP RISER
DRY VOLUMP ELEV. - Y5CARIFTEO KEY FOR
REQUIRED =3235 dA OEWATMM SOILCOHESIDN
DEVICE, ELEV. -3-" INV. OUT • 3:L51y
BOTTOM OF 9FSI UP6TREAMTOE OF DAM MSTING GROUND
N EV
ELEV•3t9.5v EI.'32950 .�-..s
CONCRETE FOI —TKN WTFRCK7 "DIA., RISER OUTLETPROTECTLON
EMBEDDED Ir INTO THCCONCRETE7 CLAY BRED DAM
KEYED INTO THE
d06TWG GROI
IM1YV.
IN= p&# 2r CL IE RCP
W31 X }1GALV. STEEL LENGTHgR' -
ANTHSEEPCOLLARS SLOPE.s %
SEDIMENT BASIN #3 PROFILE (SCALE"=40)
315 OP PROPOSED 24 "CL. III RCPRIS12RSTRU URE
,ROPOSED01C LAIRUBARREL72Lf; DAM - 326.00' RISER RIM ELEVATION= 323.755•
INVERT IN= 336.72'iINVERTOiTf 3m6m
3gD 'IF Xi INGGRADE
� r
s .R
O N OD d Q, vR N ED
N O # tIl .Y ryCry�L
O+Sa 2 +DO 2 +50 2+00 2 +2S
SEDIMENT BASIN #3 DETAIL Iu.LFa
r � � PRDAdSF
J
0MR PACTECT
107EXNLT FILTER
UNDERULYMEW
l
lb0 65Ey6Ya6r e3 AGGREF:ATG
_�rLITE[TIDN wJ ' , 'WIDP OFD_l�_ LEVATF/ a'
E [LEFB N
NERM 1w1, N1•i75', W25',
1K2' 101N.11
PROPOSED 6{g'O..R�
RPOSED EL, T2lA
INVERT INw3s6 72'L-
- INVERT OUTyA, m'
_ [t�1TkA[T[R $HALL NQ7�' -"
DISTURBWETLAND6LTYP. }-,
1
3. Recommend additional contour labels.
PJtCPOS EE /�VADEGII MUNEDEMEI(GENCY;
/ / SPILLWAY CREST ELEVATION.y4.75 ` j
PN() DV� COARSE AGGIEEGA �... " //'$ /// �IZ
PRD=DNwJGEOIERBE FILTER FABRIC // /
Engineering Review Comments
Page 4of5
4. Sheet 5 — Provide yard inlet /s in open space to protect dwellings against peak storm runoff events.
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.
b. Sequence of Construction
i. RGA/PE and contractor shall verify functionality of existing sediment basin.
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.
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."
iv. Move revised item #7 to later point in sequence of construction.
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..."
vi. Include description of ESC measures designed to prevent impact to UBP during
installation of outfall to UBP.
c. Calculations — Revise text. No water quality calculations are included or required with application.
(WP0201400004 indicates water quality compliance — statement to this effect may be helpful.)
6. Sheet 7 — Remove inlet schedule. Remove storm sewer schedule.
7. Provide data for proposed modified Ex. Sediment basin, similar to data in chart-table below:
Sediment Basin 93 design
dralrrage.area (acresj
6.34
arsasx wcx werEx
basin w&rrres: (using 2' contour intervals)
t25 -1R, M. ren
atevaticn (ftj cortinur area (sf}
volurne (W)
w
Al 9:50 41220
0
+
320 -00 44500
79.4
rw
'ern • smwr;E + - -_ nr
or=
u
32ZOO S843.D
4£9.4
_
324M 7359.0
947.3
re • sm —
326:0A BBOQ.O
1569.4
- --
r
gar�qrF�u�!
�YY@t 5tOf862. - -.
t
rimtstoreigerequlred (Vy). {67TAI
424.8
design high:waler.tM
32'4.35
tlEwa>s*rIN arlfiiee eleveEaz 00
321.82
ko 6F din yo
MOO
WA Awage prMod:atfts ale atiaa(rY)
424.8
h* WA :d darn
aiaiiN6e iRia fiCeclearaoSilicYj (34*DA)
215.6
bC9bMpfb"h -(ft)
39£
clearxxd dv tion {ft).
320.70
apprmx botion1 c$rneT.Aons:
40'433`
distatim Ron 1)
1:1
upsvenrnfece aloe:
24
(JrV STOrS¢e:
dvvrFStream slope:
'�^?.
dryFe9sle..(ey1C+']
424.8
battles:
y
porfelple MA* cred ot)
82a.75'
IWO, of LM
8Y
dry. :Wrage pre eided'at thi (4 )
4t31 �
ehFec[<aeiy�i `VTB { &3
?&.
diameter of devntsNng ar+fi4to (in)
ti
L/ Vie .(mss trot reared if ? -4
9.2
tiaCreter in flemtle hibing (in)(adfis6W)
t3
depth of water at spilNUay crass {)1}
4.25
(S?
Engineering Review Comments
Page 5 of 5
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.
D. VSMP: Mitigation Plan
The mitigation plan requirements can be found in County Code section 17 -406.
1. Sheet 3 —Label stream buffer, Upper Ballard Pond.
2. Show, calculate, and propose Mitigation for stream buffer impact associated with outfall constr. to UBP.
3. Provide mitigation at 2:1 ratio.
Engineering plan review staff are available from 2 -4 PM on Thursdays, should you wish to discuss this review. Plan
review staff are also available at 434 - 296 -5832 (- 0069) should you have questions.
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. One of the plan reviewers will prepare estimates 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 agreements will also need to be completed and recorded. The
County's Management Analyst or other staff will prepare the forms and check for ownership and signature
information. The completed forms will need to be submitted along with court recording fees.
After bonding and agreements are 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. 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;
htt2://www.albemarle.orWdeptforms.asp?departrnent--cdengmMo
Thank you - 434.296 -5832 —x3069
File: WP0201500042 Old Trail -block 27 072715