HomeMy WebLinkAboutWPO202100058 Correspondence 2022-05-18BOHLERI
County of Albemarle
Community Development Department
401 McIntire Road, North Wing
Charlottesville, VA 22902-4579
Attn: Mr. John Anderson
Dear Mr. Anderson:
9100 Arboretum Parkway, Suite 360
Richmond, VA 23236
804.893.8200
May 18, 2022
Via Federal Express
Re: WPO2021-00058
VSMP Plan Review
15t Review Response
RST Residencies
Seminole Trail and Ashwood Blvd.
Charlottesville, VA 22911
Albemarle County
V192076
Bohler is pleased to submit on behalf of RST Development, LLC, the revised VSMP Permit Plan
Review 2nd Submission for the RST Residencies. The following is our comment response letter
addressing comments received from County of Albemarle's Community Development
Department dated November 24, 2021. Each comment is addressed and responded to as
follows:
Community Development Department / John Anderson:
A. Stormwater Pollution Prevention Plan (SWPPP)
Comment 1: SWPPP
a. Sec. 6.A. / PPP Exhibit: Indicate initial location of rain gauge and non-
hazardous solid waste disposal (dumpster).
b. Sec. 6.E.: List names individual responsible for PPP, prior to
preconstruction as prerequisite to receiving a Grading Permit. Not required
for WPO plan approval.
c. Sec. 8: List names individual responsible for ESC compliance inspections
prior to preconstruction as prerequisite to receiving a Grading Permit. Not
required for WPO plan approval.
Response 1: a. The rain gauge has been added to sheet C-602 with the staging area.
The dumpster is also shown on sheet C-602 near the construction
entrance.
b. The person responsible will be Alex Mays as listed on sheet C-619.
c. The person responsible will be Alex Mays as listed on sheet C-619.
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John Anderson
VSMP Permit Plan 1s' Response
May 18, 2022
Page 2 of 4
B. Pollution Prevention Plan (PPP) — see SWPPP item 1.a., above.
C. Stormwater Management Plan (SWMP)
Comment 1: Note: Plan proposes 4.23 lb. nutrient credit purchase (24.6% of TP phosphorus
reduction required). Please coordinate purchase with Ana Kilmer at 434.296-5832
-x3246 prior to finalizing Affidavit and bill of sale, as specific project -related
information must display on Affidavit and bill of sale. Purchase is not required for
plan approval but is prerequisite to receiving a Grading Permit.
Response 1: Comment acknowledged.
Comment 2: Include Construction record Drawings (As -built) for VSMP on the plan; link to
document:
httas://www.albemarle.org/home/showl)ublisheddocument/3381 /63732751053670
0000
Response 2: The construction record drawings sheet has been added to sheet C-102.
Comment 3: Revise (title sheet) Plan Title to include WPO202100058.
Response 3: The title has been revised to include WPO202100058.
Comment 4: Coordinate slopes shown by field survey to be less than 25 percent (not steep;
therefore, eligible for development) with Engineering. Currently -mapped preserved
steep slopes are shown graded, or with improvements. Neither grading nore
improvements are permissible on preserved steep slopes. A Steep Slopes Exhibit
with discrete survey data showing portions of currently -mapped steep slopes
proposed to be graded or otherwise developed are <25%, is required, prior to
WPO plan approval of proposed grading, or improvements depicted across
preserved steep slopes. Please coordinate with Engineering.
Response 4: A Steep Slope Exhibit is currently under review with the county.
Comment 5: C-903:
a. Provide VDOT LD-204, Stormwater inlet Computations, and LD-229,
Storm Sewer Design Computations for on -site proposed SWIM collection /
conveyance system.
b. Provide VDOT LD-229 for existing storm system elements within Rt. 29
NBL RW, and Ashwood Blvd RW. Evaluate current available capacity of
inlets and pipes against flow anticipated to occur with RST Residencies
development.
c. While C-903 considers 1-10 (existing / proposed) 2-year inlet capacity, the
capacity of the pipe network downstream of 1-10 inlet must be evaluated
against additional storm runoff (10-yr event) reaching 1-10 from
development entrance on U.S. Rt. 29 NBL.
Response 5: a. Inlet and pipe computations are shown on sheet C-505.
b. Additional computations for the existing inlets and pipes were added
to sheet C-903.
c. Additional computations for the existing inlets and pipes were added
to sheet C-903.
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Comment 6: C-907:
John Anderson
VSMP Permit Plan 1s' Response
May 18, 2022
Page 3 of 4
a. Include installation sequence, guidance, notes, labels, etc. for Vault 1,
Vault 2. Ensure notes, sequence, etc. specify that SWIM facilities are not to
be installed prior to upslope stabilization.
b. Include periodic maintenance and inspection procedures, guidance, steps,
etc. for Vaults 1. 2.
Response 6: a. The Vault/ System 1 and 2 sequences have been added to sheets C-
605, C-610, and C-615.
b. Maintenance and inspection notes are shown on sheet C-909.
Comment 7: Please consider / incorporate WPO plan -related Engineering review comments on
SDP202100079, Initial Site plan, d. 11/16/21, with revised WPO plan.
Response 7: Comment acknowledged.
D. Erosion and Sediment Control Plan (ESCP)
Comment 1: C-601:
a. ST-2 is proposed immediately adjacent to property line: recommend revise
location to provide additional space for post -event remedy, i.e. measure
that may be required to limit erosion or off -site sediment transport should
less frequent events overwhelm capacity of ST-2, an event of failure. ST
location immediately adjacent to property lines is discouraged.
Response 1: ST-2 has been moved further from the property line.
Comment 2: C-618:
a. Specify concrete embedment for sediment basin primary riser; provide
buoyance calculations, unless overlooked.
Response 2: Concrete embedment has been specified on the Sediment Basin Schematic
Elevations detail on sheet C-618. Anti -flotation calcs have been provided on
sheet C-618.
Comment 3: Provide SAF between existing multi -use (ped/bike) path along U.S. Rt. 29, and
development.
Response 3: SAF was added between the multi -use path and development on sheet
C-604 and C-614.
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John Anderson
VSMP Permit Plan 1s' Response
May 18, 2022
Page 4 of 4
Comment 4: Provide interim phase ESC plan, between ESC phase I and 11, that indicates a
stage of development and stabilization with trapping devices (ST/SB) coincident
with building, parking and travelway grading prior to installation of SWIM detention
systems. Phase I reflects no grading (existing conditions; i.e., no development
grading0, while phase 11 ESC plan depicts complete development, site
stabilization- arc of site development / interim grading is missing. Provide interim
phase ESC plan that reflects proposed mass grading required to prepare building
sites, travelway/parking subgrade, etc. At this stage, traps or basin may require
alteration. Depict ESC measures required to support mass grade/next phase of
development including road/parking subgrade elevations, building pad elevation,
etc., prior to final stabilization.
Response 4: Phase I has been split into Phase IA and IB. Phase IB shows a mass grading
plan with the sediment basin and most of the sediment traps still in place.
The drainage areas to the traps/ basin have been updated per the mass
grading and the sizes have been revised. Please see sheets C-605 through
C-609 for Phase IB and sheet C-618 for the Phase IB trap sizes.
Should you have any questions regarding this project or require additional information, please do
not hesitate to contact me at (804) 893-8200.
Sincerely,
Bohler Engineering VA, LLC
4 ,'N
Ryan Yauger, P.E.
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