HomeMy WebLinkAboutWPO202100017 Plan - VSMP 2021-09-16*see
608 Preston Avenue
P 434.295.5624
Suite zoo F.immo00
TIMMONS GROUP
Charlottesville, VA 22903 wwwww.timmons.mm
September 16, 2021
David James
Albemarle County Community Dev.
401 McIntire Rd, Rm. 227
Charlottesville, VA 22902
RE: Ivy Proper— VSMP Permit Plan Review— WPO-2021-00017 —Comment Response Letter
Dear Mr. James:
We have reviewed all of your comments dated July 30, 2021 and made the necessary revisions.
Please find our responses to the comments below in bold lettering.
General:
1. Cover —Add WP0202100017 under title.
WP0202100017 has been added under the title.
Rev. 1): Not addressed.
WP0202100017 has been added under the title.
2. Please remove Sheet C4.1, 4.2, 4.3 from the WPO plan, as that is needed only for the site plan
review.
Sheets C4.1, C4.2, and C4.3 have been removed from this submittal.
Rev. 1): Not addressed.
Sheets C4.1, C4.2, and C4.3 have been removed from this submittal.
3. 1 noticed the drainfields are above the FFE of building. Will there be a pump station and where is
it located (on the site plan)? — More of a site plan review comment.
Approximate locations of septic tank and pump station have been added to plans. Septic plans
approved by VDH have been included in this submittal for reference.
Rev. 1): Addressed.
4. An easement plat will need to be recorded for the offsite construction & landscape easement. A
letter allowing this from adjacent property owner will be acceptable for WPO plan approval if
unable to record easement plat prior.
Acknowledged. Easements will be recorded prior to final approval.
Rev. 1): Acknowledged. Will be needed prior to permit issuance.
Acknowledged. Easements will be recorded prior to permit issuance.
ENGINEERING I DESIGN I TECHNOLOGY
5. Note: VDOT entrance permit will be needed prior to grading permit issuance.
A detailed turn lane warrant and queueing analysis has been performed by Timmons Group's
traffic engineers. The west -bound right -turn lane is not warranted, and the east -bound left -
turn lane is warranted but not recommended due to low volumes and no impacts to
operations. Traffic study has been included in this submittal for VDOT review.
Rev. 1): Acknowledged.
6. Rev. 1): Cover— Verify owner: According to records the parcels are owned by IVY Proper LLC,
400 Locust Ave. Suite 3., Charlottesville, VA 22902.
a. Include owner contact information. (17-403 A.2)
The owner information has been updated to be Ivy Proper LLC. The owner's address
has been updated accordingly.
7. Rev. 1): The retaining wall design must be approved prior to VSMP application approval per SE
2021- - 2condition.
a. Please submit retaining wall design plans for walls over 4' in height.
Preliminary structural engineering plans are included with this submittal as sheets S-1
& S-2.
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. Cover —Add WPO202100017.
WPO202100017 has been added under the title.
Rev.1 : Not addressed.
WPO202100017 has been added under the title.
2. Section 7— Please list the impaired waterway. It appears the nearest downstream
waterway is identified as Little Ivy Creek -Ivy Creek and is impaired. VAV-
H26R—IVC03A00.
Little Ivy Creek -Ivy Creek has been added as the waterway to which the site discharges.
Rev. 1): Not addressed.
Little Ivy Creek -Ivy Creek has been identified as the waterway to which the site discharges in
Section 7 followed by a TMDL Report for the impaired waterway.
3. Section 9 — Complete Signed Certification.
Signed Certification section has been completed.
Rev. 1): Addressed.
B. Pollution Prevention Plan (PPP)
The PPP content requirements can be found in County Code Section 17-404.
1. Show locations where concentrated stormwater discharges to and from site.
Concentrated stormwater discharge paths have been added.
Rev. 1): Acknowledged.
C. Stormwater Management Plan (SWMP)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a
SWMP. This plan is denied, and the reasons are provided in the comments below. The
stormwater management plan content requirements can be found in County Code Section
17-403.
1. Show the existing drainage divides.
Existing drainage area was shown on sheet C6.0 in previous submittal.
Rev. 1): Addressed.
2. Provide the 2-/10-yr flow & velocity coming out from the existing 24" HDPE pipe under
the railroad.
Culvert calculations for existing culvert have been added to sheet C6.1.
Rev. 1): Addressed.
3. Sheet C5 - Show drainage easement separate from the SWM facility easement. Drainage
easement over str/pipe 114 appears to be private.
Drainage easements and SWM facility maintenance easements have been revised to display
as separate entities.
Rev. 1): Addressed.
4. Sheet C5-C7: Callout & show location where weir plate is installed.
Weir plate location has been labeled on sheets C5.0, C6.1, & C7.0.
Rev. 1): Addressed.
5. Sheet C6 — Show the Tc flow paths.
Flow paths have been added for the large off -site drainage area. Other drainage areas use a Tc
of 6 minutes, which is the minimum per TR-55.
Rev. 1): Why doesn't the flow path start at the top and go to the analysis point?
Flow path has been revised to start at the top of the drainage area. Time of concentration has
been revised to 20.1 minutes accordingly.
Flow path has been extended to show route to the analysis point. Note that because it crosses
multiple drainage areas, the types of flow are only labeled on the offsite area where the time
of concentration exceeds the TR-55 minimum of 6 minutes.
6. Sheet C7 — Add note or callout to provide inlet shaping (IS-1) in structures with a 4' or
greater drop.
Note to provide inlet shaping has been added to sheet C7.0.
Rev. 1): Addressed.
7. Design Calculations report: Please change from Final Site Plan to WPO Plan (for this
review). I don't believe VDOT needs to review sections 6 & 7 of this report and can be
removed (for the site plan review).
"Final Site Plan" has been removed from the cover of the calculations book. Acknowledged
that VDOT may not require all sections that are provided.
Rev. 1 : Addressed.
8. It appears that nutrient credits will need to be purchased at the Ivy Creek bank.
Noted. Nutrient credits will be purchased from Ecosystem Services, LLC's Ivy Creek nutrient
credit bank.
Rev. 1 : Acknowledged.
9. Provide Letter of Credit availability from nutrient bank provider. -Currently 0.64 TP
required.
Letter of availability has been added to calculations book.
Rev. 1 : Addressed.
10. Nutrient Credit purchase required prior to plan approval.
Noted. Nutrient credit purchase will occur prior to final approval.
Rev. 1 : Acknowledged; Comment still valid.
Acknowledged. Nutrient credit purchase will occur prior to final approval.
11. SWM agreement required prior to plan approval.
Noted. Per correspondence with Ana Kilmer, the County will coordinate the SWM agreement
with the developer prior to final approval.
Rev. 1 : Acknowledged; Comment still valid.
Acknowledged. SWM agreement will be coordinated prior to final approval.
12. Note: A SWM deed of dedication will need to be recorded with the easement plat.
Noted. Deed of dedication will be recorded with the easement plat, prior to final approval.
Rev. 1 : Acknowledged.
13. Rev. 1 : 1 don't consider this a prior development — Use the new development VRRM.
"Prior developed lands" means land that has been previously utilized for residential,
commercial, industrial, institutional, recreation, transportation, or utility facilities or
structures, and that will have the impervious areas associated with those uses altered
during a land -disturbing activity."
VRRM has been revised to the New Development spreadsheet as requested.
14. Rev. 1 : Please verify: I measure the disturbed acreage to be a bit larger than the 0.79ac
reported.
The limits of disturbance acreage has been revised to 0.96 acres. Stormwater management
calculations have been revised accordingly.
15. Rev. 1 : Show the cross-section and 10-year WSE for the trapezoidal channel.
The cross-section and 30-year flow and normal depth for the trapezoidal channel has been
shown on sheet C6.0.
16. Rev. 1 : Provide separate profile and cross-section for the UD system for installation (to
scale & list dimensions).
Shop drawings for underground storage pipe system have been added to sheet C3.2.
17. Rev. 1 : Provide a ladder for maintenance access for the UD system MHs and provide
detail.
Shop drawings for underground storage pipe system have been added to sheet C3.2.
18. Rev. 1 : Provide installation notes for UD system & components.
a. Add note that all seals/connections for US system to be made watertight.
Shop drawings for underground storage pipe system have been added to sheet C3.2.
19. Rev. 1 : Provide inspection and maintenance notes for the UD system.
Shop drawings for underground storage pipe system have been added to sheet C3.2.
20. Rev. 1 : Add this list to plan — Construction Record Drawing for VSMP.
The Construction Record Drawings (As -built) for VSMP list has been added to sheet C1.0.
D. Erosion and Sediment Control Plan (ESCP)
Virginia Code 62.1-44.15:55 requires the VESCP authority to approve or disapprove an ESCP.
This plan is disapproved, and the reasons are provided in the comments below. The erosion
control plan content requirements can be found in County Code Section 17-402.
1. Critical slopes waiver will need to be approved.
Critical Slopes Waiver was approved by the Board of Supervisors on May 19, 2021.
Letter of approval has been included in this submittal for reference.
Rev. 1 : Addressed.
2. Sheet C3.2: Show perimeter controls in place including safety fence for the parking area
and silt fence along the front for the demoing activities.
Safety fence has been added along the edge of the existing parking lot. Silt fence along
the front of the site was provided in previous submittal.
Rev. 1 : Addressed.
3. Sheet C3.2/3.3:
The LOD must include the proposed pipe connection from Str. 102 to Ex. 100.
LOD has been revised to include Pipe 101.
Rev. 1 : Addressed.
b. The County requires paved wash rack construction entrances. Please change the
detail of CE to the one shown in our design manual [ACDSM, p. 7-8].
Paved Wash Rack detail has been added to sheet C3.1. Construction Entrance
on sheet C3.3 has been revised to Paved Wash Rack. Note that Virginia DEQ
standard Construction Entrance remains in Phase I Erosion & Sediment Control
plan because that area is not paved in the existing condition.
i. Show location of sediment trapping device.
Inlet Protection is provided on either side of Paved Wash Rack. Note
that these Inlet Protections were included in previous submittal.
Rev. 1 : Addressed.
c. Provide detail of CWD used. Provide profile of the channel behind CWD. If slope
is greater than 2%, the channel shall be stabilized in accordance with Spec. 3.17,
SCC. Ensure runoff released from end of CWD is released to a stabilized outlet or
channel.
CWD detail was provided on sheet C3.1 in previous submittal. CWD has been
added to legend on sheets C3.2 & C3.3, to clarify that it is the same as the
Diversion Dike in Spec. 3.09. Note has been added to detail on sheet C3.1 to
indicate that channel shall be stabilized with permanent seeding, in accordance
with Spec. 3.17 and Spec. 3.32.
Rev. 1 : Show what the max 2-yr velocity for channel(s) and appropriate liner
type needed. Add outlet protection to end of CWD.
Calculations showing 2-year velocity of 3.88ft/s have been included in the
calculations book. Note has been added to detail on sheet C3.1 for channel to
be stabilized with bermudagrass where slopes exceed 2%. Outlet protection
has been added to CWD; outlet protection detail has been added to sheet C3.0.
d. Rev. 1 : Show permanent stabilization to ditch area along road after demoing
has occurred.
Blanket matting has been added to the ditch area along the road on sheet
C3.3.
4. Sheet C3.3 — Callout to detail or add note for >3:1 slope stabilization plantings. For grass
stabilization on constructed slopes, the maximum steepness is 3:1. Slopes steeper than
3:1 must be permanently stabilized with landscaping vegetation hardier than grass,
which will not require mowing. [ACDSM]
Note has been added to sheet C3.3 requiring vegetation hardier than grass. Blanket
matting was provided in areas with slopes steeper than 3:1 in previous submittal
(unchanged).
Rev. 1 : Addressed.
S. Rev. 1 : Sheet 3.2: Concentrated runoff is not allowed to run across travelways. You
would need to come up with a solution there at the entrance.
Erosion & Sediment Control Plan — Phase I has been revised to install portion of pipe
network under existing and proposed entrances at beginning of work. Concentrated
runoff will enter directly into the existing storm pipe at the east end of the site, as
proposed in the final condition.
6. Rev. 1 : Please verify: I measure the disturbed acreage to be a bit larger than the 0.79ac
reported.
The limits of disturbance acreage has been revised to 0.96 acres. Stormwater management
calculations have been revised accordingly.
We have included PDF copies of the plans and calculations for your review. If you have any
questions or comments, please feel free to email me at clint.shifflett(@timmons.com .
Sincerely,
Clint Shifflett, PE
Project Manager