HomeMy WebLinkAboutSDP202100095 Review Comments Initial Site Plan 2022-01-28�q oe nt 401 McIntire Road, North Wing
Charlottesville,VA22902-4579
County of Albemarle Telephone: 434-296-5832
m COMMUNITY DEVELOPMENT DEPARTMENT
WWW.ALBEMARLE.ORG
Initial Site Plan review
Project title: Albemarle County Service Authority Avon Maintenance Yard
Project file number: SDP2021-00095
Plan preparer:
Kevin Pennock, PE, koennock@dewberry.com
Dewberry Engineers, 4805 Lake Brook Drive Suite 200, Glen Allen, VA 23060
Owner or rep.:
Alexander Morrison, PE, aorrisonAserviceauthority.org
Albemarle County Service Authority
168 Spotnap Road, Charlottesville, VA 22911
Plan received date:
29 Dec 2021
Date of comments:
28 Jan 2022
Review Coordinator:
Kevin McCollum
Reviewer:
John Anderson, PE
Engineering review comments (for Final Site Plan approval):
1. G0.01
a. Please remove SWM-related sheets C6.06-C6.07 (include with WPO202100071).
b. Please revise Civil sheet Drawing Index: strikethrough ESC /SWM-related sheets not included
with SDP202100095.
2. C3.01
a. Please submit retaining wall design, when available, at earliest convenience. Wall ht.>4-ft.
requires sealed non -generic retaining wall design. Wall ht.>3-ft. requires building permit, and
safety railing. C5.01 typical for CMU block retaining wall is generic. Provide specific design,
including geosynthetic length of anchoring embedment, plan/profile with wall stationing, etc.
b. Provide retaining wall handrail labels, ref. C5.01 detail.
c. Provide CG-6 for 14 parking spaces on west side of parking west of building, or CG-2 if flow line
is designed into the paved surface near rear wheels of parked vehicles. C3.03 indicates 2.0%
paved grade away from west side of building, and provision should be made for storm runoff
capture and conveyance. If flow line in pavement, provide surface storm runoff capture at south
end of parking on west side of building. Runoff may not exit pavement to an unpaved verge,
though runoff may exit to a hard surface surrounding a grate inlet (set in a concrete frame, for
example).
3. C3.04
a. Provide outfall design (recommend MH) to redirect flow (SWM facility discharge) such that it
aligns with riprap. Design provided does not include element/s sufficient to redirect discharge at
outfall. We anticipate discharge may skip over and escape riprap, and cause erosion downslope.
A physical structure, preferably MH, is needed to redirect flow so it aligns with riprap.
b. Ensure proper ditch lining on south side of site access. Ditch extends —1,140 LF with vertical fall
of— 80' (elev.: 608' - 526% and likely requires blanket matting, or riprap armor. Provide velocity
calculations as well as lining type. Provide typ. sections for different sections of ditch.
Engineering Review Comments
Page 2 of 2
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4. C4.05: Recommend sanitary sewer profile Note /label requiring 95% compaction for fill beneath Str. C05
and pipes to either side since installed in substantial fill section.
5. C4.06
a. STMI, STM2, and pipe between: recommend storm sewer profile note Aabel requiring 95%
compaction.
b. Although 0.50% is acceptable as minimum pipe grade, length of pipes (168' 212') at Min. grade
leaves no room for error during construction. As -built pipe slope < 0.50% requires hydraulic
calculations to ensure self-cleaning velocity is maintained throughout reach of pipe. Slopes <
0.50% may require post -installation remedy /expense. It appears that pipe slope between STM 1
and STM2 and between STM2 and STM3 may be increased slightly. Engineering recommends
increase pipe slope slightly, to 0.60% or more (0.38' vertical, if an additional 0.1% over 380').
c. Provide VDOT SL-1 label on profile (safety slab) for MH STM3, STM4, STM7.
d. Provide VDOT SL-1 detail on the plans.
6. C4.07
a. Provide 95% compaction labels /notes for fill sections at STM15 (and pipes to either side),
entirety of STM 19 to STM 21 profile, and STM 17 outfall, and pipe at outfall.
7. C4.08: Revise LD-347 table to include IS-1 (inlet shaping) for MHs with change indirection of flow:
STM3, STM6, STM 15, for example. Table lists IS-1 for MHs 7, 5, 4, only.
Thank you.
Please call if any questions — tel. 434.296-5832-x3069, or email ianderson2(a),albemarle.org.
SDP202100095_ACSA Avon Maint Yard 012822