HomeMy WebLinkAboutWPO202100057 Correspondence 2021-12-13I® COLLINS ENGINEERING
December 6, 2021
Emily Cox
Department of Community Development
401 McIntire Road
Charlottesville, VA 22902
RE: Pantops Shopping Center— Enterprise Carwash (WP02021-00057)
200 GARRETT ST, SUITE K CHARLOTTESVILLE VA 22902
��434.293.3719 PH 434.293.2813 FX
www.coll ns-eng ineeri ng.com
Thank you for your comments dated November 12, 2021 on the above referenced project. Below are our responses to
the remaining comments on the road plans.
A. Stormwater Pollution Prevention Plan
1. Attached is the signed registration statement
2. The updated plans have been added to the SWPP for final approval.
3. The certification in Section 9 has been signed, as requested.
4. As discussed, both properties are listed in the documents, but the owner is the same. Therefore,
there is just one signature for the project.
5. The owners email address has been provided. The email is for the project manager at GEMC.
B. Pollution Prevention Plan
1. The plan view of the PPP has been added to the SWPP, as requested.
C. Stormwater Management Plan
1. A SWM agreement will be recorded. We will each out to Ana this week to prepare the agreement.
2. The nutrient credits for this project will be purchased in the next two weeks. We will reach out to
Ana as well on this to complete the purchase.
3. As discussed in the field, riprap will be added to the outtall below this curb cut. See the WPO plan for
the addition of the riprap at the outtall to be added to this project. The riprap is added to the overall
grading plan (sheet 3) and Erosion & Sediment Control plan (Sheet 4).
4. A certified exhibit has been provided to map the limits of the preserved slopes on the property.
5. The carwashing activity will occur within the building. This will be an automatic carwashing facility
where the water will be filtered and recycled for use.
6. The drainage areas match the limits of construction pretty closely. The drainage area is shown and
the offsite drainage areas have been added. The existing inlets have been labeled. Also, attached to
this letter is a GIS print-out of the drainage area in this location. The surface flow in the parking lot
does not reach the limits of construction of the new parking lot. This drainage flows across the
travelway to the existing inlet, as shown.
7. The existing roof drainage downspouts have been added and shown on the overall drainage plan.
The plan shows the roof drains behind the shopping center building and behind the enterprise rent -a -
car building. The design has been updated to pick up (2) of the existing roof drains behind the
enterprise rent -a car facility and route them to the new drainage facility. This will prevent these roof
drains from draining across the proposed drive aisle.
8. As discussed, there is a site plan amendment under review for the proposed improvements that is
just about ready for approval. A SWM easement plat has also been submitted for review and
approval.
9. As discussed, the existing riprap along this outtall will be added to as shown on the overall grading
plan and erosion control plan. This additional riprap will provide additional protection of the slopes
in this area. The run-off from the site through the storm sewer has been attenuated, so there will be
no additional run-off or sheet flow across these slopes or at the outfall that will cause erosive flows.
10. A FDP permit has been submitted with this application, as requested. The additional riprap has been
shown on the grading plan and on the erosion control plan.
11. The 100' stream buffer has been added to the plan sheets, as requested.
12. The floodplain elevation has been added to the plan sheets on the overall grading sheet and erosion
and sediment control sheet, as requested.
13. The energy balance has been updated to show the adequate flow through the existing outFall pipe, as
requested. The system is adequate, based on the attached calculations. Please see updated SWM
Calcs Packet.
14. As discussed in the field, a video of the existing pipe is no longer required.
1S. The pipe calculations from the SWM facility to the outfall have been included in the plans on Sheet 7.
and calculations, as requested. The other onsite pipe design is already shown in the site plan
amendment.
16. A cross section has been added to sheet 3 showing the section between the preserved slopes,
proposed wall, and grading of the drive aisle.
17. The detail design of the retaining wall has been added to sheet 3.
18. The retaining wall shall serve as a guardrail. It will have a small railing on top, meeting the required
42" guardrail height. The retaining wall will be 36" above the drive aisle acting as a guard rail to the
drive aisle with a 6" railing on top, meeting the required 42" guard rail design. We have used this
design on similar projects where the concrete wall serves as a retaining wall.
19. The dimensions of the drive aisle have been added to sheet 3. The drive aisle is 12' in all locations,
per the Albemarle County requirements.
D. Erosion Control Plan
1. The cross sections on sheet 3 show the location of the preserved slopes and the wall and how the
wall will be constructed without disturbing the preserved slopes. Specifically cross-section C shows
the construction of the wall in close proximity to the preserved slopes.
2. Plantings have been added to the Erosion control plan and grading plan (Sheet 3) indicating plantings
along the 2:1 slopes. The shrubs, as indicated on the plan sheets, will be planted on a 6'x6' grid.
3. Perimeter control has been added for the work to tie-in to the existing sanitary sewer with the
lateral.
4. The E&S narrative has been updated to address the added fill on the site and how it is phased with
the wall construction. Note #6 has been updated to indicate that the wall shall be constructed prior
the filling of the site, to protect the downstream preserved slopes.
Should you have any questions, please feel free to contact Scott Collins at scott@collins-engineering.com.
Sincerely,
Scott Collins, PE