HomeMy WebLinkAboutSUB201400169 Review Comments Road Plan and Comps. 2014-12-05'A
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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:
North Pointe Middle Entrance & Rt. 29 Improvements
Plan preparer:
Brian Mitchell, P.E./Townes Site Engineering -9850 Lori Road, Suite 201
Chesterfield, VA 23832 [bmitchell(&cctownes.com ]
Owner or rep.:
CWH Properties Limited Partnership, P.O. Box 5526
Charlottesville, VA 22905
Plan received date:
14 October 2014
Date of comments:
5 December 2014
Reviewer:
John Anderson
cc:
Glenn Brooks, County Engineer
David Benish, Chief of Planning, Albemarle County Community Development
Troy Austin, Area Land Use Engineer, Virginia Department of Transportation
Claudette Grant, Senior Planner, Albemarle County Community Development
Engineering has completed a preliminary review of Application SUB2014- 00169.
R o a d P l a n s (SUB201400169)
1) Revise CE to paved construction entrance, per ACDSM detail (p. 27). Revise ESC legend to
show PCE, not CE [link: b !V: / /www.albemarle.orWdoartment .asp ?department= cdd &relpa�ze =4447]
2) CC8: Include paved wash rack detail, per ACDSM (p. -27 [or p. -8: pending rev. of ACDSM]).
3) In addition to #1, relocate PCE south approximately 800 -ft to drive slated for demolition
(drive visible on C -2, C -2A, C -3, C -3A). Proposed location grants access to a narrow portion
of the site, leaves construction traffic isolated north of tributary stream to Flat Branch.
4) Turn and taper lanes — Eliminate 4:1 tapers. VDOT Road Design Manual, Appendix F, Sec. 3. Ref.
VDOT Road Design Manual Turn Lane Criteria for Single and Dual Lanes requires substantially
longer transitions.
5) Furnish ACCD /Engineering copy of TIA supporting Modified Zoning Application Plan.
Given relative complexity of project, it is best to ask rather than search files for TIA, which
may exist in original or revised versions. Reviewer is relatively unfamiliar with project/TIA.
6) Show posted speed limits, plan view, Northside Drive and Rt. 29.
7) Furnish pipe /inlet calculations —use VDOT Design Manual, Appendix 913-1, inlet
computations (LD -204) format.
8) Furnish HGL table or similar data to show that all 10 -yr flow is contained within conveyance
system, without surcharge. Design must avoid pressurized conditions.
9) It appears (unless 23- Aug -2006 proffers amended) that road improvement phasing stipulates
a 12 -ft wide thru lane extending 1000' N of the Middle Entrance to Airport Road (C -1A). It
also appears Rt. 29 NBL improvements meeting Phase I /II proffer conditions are required.
Items 10 -16 relevant if 12 -ft wide thru -lane to Airport Rd not required by VDOT, or ACCD/Planning at this time
10) Modified Zoning Application Plan (Mod -z Plan- sent as e- attachment, Wed 12/3/2014 10:14
AM) shows improvements to Northside Drive more extensive than road plan. RTL
storage /transition is approx 400', while C4 (road plan) shows 100' RTL storage, 100' transition
(taper). Revise Northside Drive road plan consistent with Mod -z Plan. [C -1B is Modified
Engineering Review Comments
Page 2 of 5
Application Plan, rev. 6/11/14. Road plan differs from Mod z -Plan across plan sheets.]
11) Mod z -Plan shows Rt. 29 NBL improvements south of Rt. 29/Northside Dr. intersection
extending 900 -ft ±. Road plan shows less: 448' ±. Please reconcile road plan -Mod z Plan.
12) Mod z -Plan shows Rt. 29 NBL improvements north of Rt. 29/Northside Dr. intersection
extending 500 -ft ±. Road plan shows zero (0'). Reconcile road plan -Mod z Plan.
13) Mod z -Plan shows Rt. 29 SB hybrid [not thfu] lane west of existing southbound lanes; that is,
to the outside of Rt. 29 /SBL, with approx 950 -ft extending N of intersection, 1000' S of
intersection. Road plan proposes inside lane location of equivalent length; that is, a lane
adjacent to median that ends with an abrupt 48' transition to 2- lanes. Revise road plan
(combined 1950') lane location, consistent with Mod z Plan.
14) Revise thru -lane label, unless 12' -W lane extends 1000' N of Middle Entrance to Airport Rd.
15) Revise 48' transition to 12:1 (144', Minimum), except VDOT may require longer transition.
It is our understanding VDOT may require 200' L taper, unless lane extended to Airport Rd.
16) Mod -z Plan shows Rt. 29 RTL onto Ex. Northside Drive (W of Rt. 29) extending approx 325'
(transition + storage) N of intersection. Road plan shows no RTL. Reconcile road plan -Mod z.
17) With respect to items 10 -16, Modified Application Plan was attached to 12 -3 -14 Townes'
email [Wed 12/3/2014 10:05 AM]. I spoke with Planning Div, asking if there is any reason
road plan design should depart from design shown in Modified Application Plan. Planning
suggests there is no reason that road plan design features would depart from those shown in
Modified (Zoning) Application Plan.
18) Show steep slopes [18 -30.7] on sheets C -3, -3A, -6, -6A, -7, -7A.
19) Sheets C- 6, 6A, 7, 7A: provide existing contour labels. —Also #61, below.
20) C -3A: 45 -ft unbroken vertical interval of 2:1 pond/basin side - slopes is unacceptable. Ref.
18- 30.7.5 for recommended design approach, including reverse slope benches and surface
water diversions. Engineering disapproves concept grading of pond, C -3A. Revise grading.
21) C -3A: Revise any 2:1 permanent contours on north- facing roadway embankments, Northside
Dr East, SRI 570. Permanent 2:1 slopes may not exceed 20' vertical interval. Utilize design
elements listed at 18- 30.7.5.c.I [ —Also: ZMA -00 -009 Proffer Condition #10, Overlot grading plan,
condition of Approval.]
22) C- 12/12A: Several MH structure tops appear below grade (STR -1, 12, 10, 55) — please revise.
23) C -12A: Str -57 (DI -3B) projects above grade; revise profile.
24) C- 12/12A: Avoid extremely close placement of MHs to existing waterline or gas line (STR -24,
18, 29, 57).
25) C- 12/12A, C -14A: Provide bedding detail sufficient to ensure minimal settling for those MHs
located entirely in fill sections: STR -6, 45, 55, 57).
26) C -12: STR -36 —show end section in (pipe) profile view.
27) C -12A: STR -51 —show end section, (pipe) profile view
28) C -12: Storm 22 -28 profile: show tie to existing 24" CMP.
29) C -12: Storm 29 -33 profile: show tie to existing 24" CMP.
30) C -12: Storm 6 -16 profile: revise existing structure label to read Ex. 36" X 36" box culvert.
31) Review design STR -62 (36" DIA RCP CL III), which is downstream of 36" X 36" box culvert
(C -4). Receiving structure capacity cannot be less than upstream structure.
32) C -13A: Sta. 33 +00.00 cross - section appears twice. Options: leave or delete.
33) C -14: Include pavement classification/design table.
34) C -14: Min curb radius =3', Median/Middle Entrance Typ. sec. ( <3' R subject to brittle fracture)
35) C -14A: Method "A" storm pipe bedding and backfill detail is unreadable. Revise so readable.
36) C -14A: Trench bedding /force main & backfill details reference CITY specifications; revise.
37) VDOT must approve road plans.
Engineering Review Comments
Page 3 of 5
Advance comments: With V S M P Application
38) Show stream diversion required to route section of stream through pipe beneath Middle Entrance.
400 LFf stream will be relocated to proposed pipe system. In plan view, detail ESC measures
required to divert, avoid, and minimize aquatic resource impacts.
39) C -8: Furnish stream diversion/bypass detail. This element is critical. A schematic of stream
bypass is required [VESCH, Plate 3.25 -1 or similar].
40) C -8: Furnish temporary vehicular stream crossing detail [VESCH 3.24].
41) C -8: Furnish dewatering structure detail [VESCH 3.26].
42) C -8: Include VDOT STD details: inlet shaping; safety slab [MH height >12'], MH steps [ >4'];
and pipe end section.
43) Please reference /incorporate County Engineer's email comments in revisions, as appropriate.
[11/21/2014 2:28 PM (GMT- 05:00); Townes Engineering responded Nov 24, 2014 1:43 PM]
44) C -lA: Consider, model, and present calculations and narrative to aid review and ensure design
meets ZMA 00 -009 (23- Aug -06) Proffer #4.2 Stormwater Management Plan if any element
included in Proffer item 4.2 is associated with North Pointe Middle Entrance (Phase II).
4.2 Storm,, ater Management flan. The stormw°ater' best management practices
(" l3MP ") plan for the Project shall be prepared, and all somtwater management facilities firr the
Project shall be designed and constructed. to accommodate all current stormwater discharge from
Tax Map Parcel 032A0 -02 -00 -00400 (Northwoods Mohile Home Park Development) and from
the existing, developments on the northeast and northwest corners of'Proffit Road and L).5. Rnute
29, specilic.illN the followinu parcels shown on the current Albemarle C'ount3 iax maps: tax map
32. parcel: 38. 8A, '9. and 7�)A, tax map 32A. parcels 2 -1, 2 -1A, 2 -]A], 2 -113. 2 -lC and 2 -1 D.
The swrmwater management facilities shall mitigate the stormwater qualiti, and quantitN
impacts. fior the stormwater generated both within the Project and fior such existing offshe
conditions as described herein. as though the entire preexisting, condition of the drainage area is
an undeveloped wooded site and is being developed to the existing; off -site conditions and the
proposed on -site conditions. In addition, biofilters shall comprise a minimum of thirty -three and
one -third percent (33 11%) of the total required parking lot landscaped areas within the
"Commercial Area" of the Prgjcct, as such Commercial Area is delineated on Sheet G of tlzc
Application Plan {"Sheet G").
#45 -52, Sheet C -6 A.
45) Show limits of construction (LOD). Use symbol from Overall Conceptual EC Plan legend to
delineate LOD. ONLY drainage divides are shown. Report Area (Ac.) of project LOD.
46) Update LEGEND, C -1, using flattened oval symbol:
Wass sroRN unc nAS eiEry ieisuu 'D.�'� " "�'
AREAS DRAINING ro SNM/BMP /SEgNENT BASIN
STORM SEVER NETN'oRNS AS — AREA IS
M. EACH PROJECT SHALL BE IMPLEMENTED IN SUCH
AT — MCI— CRY AND NET W -SE TIC 1
HE
T AMOUNT PRONGED R, SEDIMENT BASIN No t ANS
N A—RANCE INTN NNE VA EROAON AND
r MR OL HANDBOOK: CURRENT fdE..
STORM W A- MP NO. l 41ALL CONVEY TPE
T. ETwaR✓sAASRSxown n unN ➢xG E NNO AND NEW
ROSIOON COQ
noe c �� s T rErtc
°eo° —)� —�— TErwuvr mvExoon m
ST � TCWORARY SEGMENT TRAP
313
�TH P IN T E UHIT OF CCOnTRUCUOR
47) Revise construction sequence Note #1: pre - construction meeting will be held at County Office
building, 401 McIntire Rd/Charlottesville, not on -site.
48) Delete construction sequence Note #4, or revise: contractor may not clear preliminary limits of
Engineering Review Comments
Page 4 of 5
disturbance prior to installing silt fence "along the limits of the disturbed area," unless this note is
intended to allow SF installation only. Please clarify.
49) Revise construction sequence Note #7: design engineer to verify existing sediment trap is in good
working condition. Furnish As -built of existing, and provide plan/profile scale drawings of
ST -1.
50) MAINTENANCE NOTES- inspections should correspond to GP inspection frequencies (GPNARl0 —
Part II F. link: htW: / /www.deg.virizinia.gov/ Portals/ 0/ DEQ/ Water/Publications /CGP2014.pdf)
51) Label sediment trap (plan view) floor dimensions: L x W (ST -1, ST -2).
52) Show temporary /permanent stabilization (TS /PS), straw mulch (MU), and dust control (DC).
53) Include TS, PS, MU, DC in Legend, CC =1.
54) C -7A: Furnish (& show grading) 10'W vehicular access to SWM facility [18- 32.7.4.2 & 14 -431].
55) C -7A: Shift IP label to uncover structure #10 identifying label.
56) Ensure design complies with Specific /General conditions of state (DEQ) and federal (USACE)
permits issued separately, directly to Applicant.
57) C-9 /(other): show soil types boundaries /label soil types.
58) Provide weighted Curve Numbers needed to calculate pre- /post - development runoff (CN). Use
TR -55 (SCS) 24 -hr distribution as basis of hydrologic calculation/hydraulic design.
59) Ensure CNs consistent with hydrologic soil groups.
60) Furnish scale profile drawing of sediment trap 2 (ST -2).
61) Sheets C- 6, 6A, 7, 7A: provide existing contour labels. —Also #19, above.
62) C -11: Label or list DA acreage.
63) Furnish CNs for routing calculations for SWM for Middle Entrance (ref. GEB email, Fri
11/21/2014 2:28 PM, comments regarding puzzling routing data included with SWPPP).
Storm Water Pollution Prevention Plan for North Pointe Development, Dec -2013, rev. May 2014 (SWPPP):
64) Tab 21 should include overall SWM/BMP Analysis Maps. Maps are missing. Furnish maps.
Unable to cross - reference road plan SWM BMP (Retention Basin II, 4 WQ Volume /phosphorus
removal efficiency =50 %; apparent BMP for Middle Entr./Rt. 29 Improvements) with SWPPP.
65) Further WPO review depends upon Overall Conceptual SWM Plan, on details that clearly
correlate Middle Entrance SWM/BMP (C -9A, C -10, VSWM Handbook Appendix 5D
performance -based water quality calc worksheets, C-1 IA) with SWPPP, Tab 22. Tab 22 lists
SWM/BMP Nos. 1 -9A. It is unclear which, if any, Tab 22 BMP corresponds with Middle
Entrance SWM/BMP shown on plans.
66) With respect to multiple sources of information, please clarify:
a. C-1 IA: 5D -12 worksheet includes 4.42 Ac. value (Water Quality Volume Calculation), but
preceding steps (worksheets 5D -5, 5D -9, 5D -10) use 10.80 Ac. value.
b. If basin (pond) is meant to be sized =4 x WQV and watershed =10.80 Ac., then pond appears
undersized.
c. Recent e-mail references Phase II Middle Entrance Improvement Acreage =17.20 Acres
[Nov-24,2014 1:43 PM, B. Mitchell to GEB].
d. HydroCAD routing references 8.830 Ac. area.
e. SWPPP; SWM/BMP Nos. 2 -2A appear to control runoff from 14.1 Ac. These BMPSs
appear positioned to receive runoff from an area nearly the same as areas shown on C -11, but
also receive runoff from more impervious area (ultimate development). Multiple sources of
information lend confusion. —Also, #65, above.
f. HydroCAD models are based upon Rational Method. ACCD requires SCS 24 -hr distribution
hydrologic modeling. For Albemarle County: 24 -hr 2 -yr event =3.7 in; 10 -yr event =5.6 in.
Revise routings.
g. It is not possible to evaluate drainage items, or properly evaluate design given fluctuating
drainage areas, treatment areas, drainage divides, etc, and cross - references that fail to
correlate SWPPP with road plans (or WPO plans). Clarity is imperative.
h. Please consider which schematics, tables, areas, maps, DA values, and BMPs lend clarity,
which should be revised or removed. Ensure schematic or descriptive narrative build a
Engineering Review Comments
Page 5 of 5
consistent and understandable picture of development, drainage design, and SWM /ESC
control.
i. Include: time of concentration; CNs (and how derived; i.e., land cover weighting); % pre -
/post- impervious cover; hydrologic soil types.
j. Revise SWPPP /AApnendix B to include column for hydrologic soil group.
k. Revise runoff coefficients (or better, use Curve Numbers) consistent with B/C hydrologic
soil groups (tables /C -9, C -9A).
1. All routings must clearly identify which SWM facility/basin is being evaluated. In the case
of SWM facility shown on North Pointe Middle Entrance plans (C -10), it appears this
facility is an interim SWM facility. Furnish explicit description of which developed areas
the SWM facility on C -10 treats, how long it will operate, and if replaced, what replaces it.
m. If SWMBMP shown on Middle Entrance plans is an interim facility, consider ultimate (or
concept) SWM plan. Correlate ultimate SWM plan to proposed design for treating storm
runoff from North Pointe Middle Entrance /(Phase II) Rt. 29 Improvements.
n. If SWMBMP facilities 2 -2A will at some point replace the 4 X WQV pond (basin) shown on
C -10, then, at this point provide pre- /post - development Part IIC criteria review based upon
pre- existing forested condition (worksheets on C -I IA appear to account for this; 0%
impervious) and immediate plans to construct entrances with surface width approx 50%
wider than the Middle Entrance shown on SWPPP, Tab 27 insert, titled "Overall SWMBMP
Drainage Map."
o. It is important to note that SWPPP presents considerable detail concerning ultimate use.
Ultimate use appears not to preserve the SWM pond shown on Middle Entrance plans.
Please feel free to call: 434.296 -5832 — x3069. Engineering staff is available to discuss project comments, or
design each Thursday. Meetings are scheduled for 30 -min blocks. Please contact reviewer if you would like
to schedule a meeting.
Planning Division, ACF &R, ACSA, and VDOT road plan comments will be sent as soon as received. I was
remiss in distributing road plans to ACCD/Planning, and ACF &R. I apologize for any delay due to error.
Thank you.
SUB201400169 -North Pointe - Middle Entr- Rt29- 120514.doc