HomeMy WebLinkAboutWPO201900034 Correspondence 2020-02-18
CIVIL ENGINEERING | ENVIRONMENTAL | SURVEYING | GIS | LANDSCAPE ARCHITECTURE | CONSTRUCTION SERVICES
608 Preston Avenue
Suite 200
Charlottesville, VA 22903
P 434.295.5624
F 434.295.8317
www.timmons.com
February 14, 2020
Matt Wentland
County of Albemarle
401 McIntire Rd, Rm 227
Charlottesville, VA 22902
RE: UVA Encompass Health Rehabilitation Hospital – VSMP Permit Plan Review –
WPO201900034 - Comment Response Letter
Dear Mr. Wentland:
We have reviewed all of your comments from January 31, 2020 (Rev.2) and made the necessary
revisions. Please find our responses to the comments below in bold lettering.
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. Provide a completed Registration Form. Section IA and Section VI will need to be filled
out.
The Registration Form shall be completed and signed prior to VSMP approval.
(Rev.1) Comment not addressed, response noted.
Acknowledged. Form to be signed prior to approval.
(Rev.2) Comment not addressed, response noted.
Registration Form has been provided.
2. Complete the Signed Certification (section 9 of the SWPPP).
A signed certification to be provided prior to VSMP approval.
(Rev.1) Comment not addressed, response noted.
Acknowledged. Form to be signed prior to approval.
(Rev. 2) Comment not addressed, response noted.
Certification has been included in SWPPP.
B. Pollution Prevention Plan (PPP)
The PPP content requirements can be found in County Code section 17-404.
1. The PPP is acceptable at this time.
Acknowledged
C. Stormwater Management Plan (SWMP)
VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a
SWMP. This plan is disapproved, 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. This plan cannot be approved until the Loop Road VSMP and Road Plans have been
approved and bonded.
Acknowledged. The Loop Road VSMP and Road Plans will be approved and bonded prior to
WPO201900034 approval.
(Rev.1) Response noted.
Loop Road drawings have been approved. Bonding currently in process.
(Rev. 2) Response noted.
2. The riprap below Outlet 100 is shown on a slope and not going into a defined channel.
The riprap outlet has been moved further down the slope to outfall into an existing channel.
(Rev.1) Comment addressed.
3. While the existing pond does provide quality and quantity control for the drainage area,
the discharge from the site will still need to make it to the pond without causing
erosion. Provide measures and/or an analysis to show how the site’s discharge meets
DEQ IIB or IIC quantity compliance.
A 84” CMP Detention system has been provided to meet channel protection and flood
protection requirements. Sheet C6.2 has been revised to provide calculations for this system.
(Rev.1) Comment addressed. In the future, the analysis point should be shown at the point of
discharge into the natural channel (which it appears the calculations match).
The proposed stormwater management system has been revised to reflect a dry pond.
(Rev. 2) See Revision 2 comments below.
Revision 1 Comments:
4. Prior to plan approval, an easement plat with deed will be required for the SWM facility
easement. The deed will be prepared by staff after submittal of the plat.
Acknowledged. Proposed easement line work can be found on Sheet C6.3. A plat will be
submitted for County review following acknowledgement/approval of preliminary alignment.
(Rev. 2) Response noted, however Sheet C6.3 was not found in this plan set. Please see Site
Plan comments for additional required easements.
Sheet C6.3 has been included.
5. Provide an additional access point to the UG detention on the other side of the weir
plate.
The UG detention system has been removed from the project.
(Rev. 2) No longer applicable.
Revision 2 Comments:
6. The minimum angle between inflow and outflow pipes is 90 degrees. Please revise pipe
system at inlet 208.
Pipe alignment has been revised.
7. To prevent erosion, the riprap should extend from the pond outfall to the stream. Refer
to plate 3.19-1 in the VESCH manual and verify there is no objection from the Army
Corp.
Riprap has been extended to the stream, and Army Corps has been notified of the
design.
8. Include a maintenance and inspection schedule for the pond.
Dry pond maintenance notes have been added to sheet C1.0.
9. Include the County As-built requirements on the plans.
As-built requirements have 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. Provide perimeter measures below all areas of disturbance.
Additional perimeter measures have been provided to capture as much runoff as possible. See
Sheets C3.2 – C3.4.
(Rev.1) Comment partially addressed. Controls are required below all disturbances. Several
areas still have nothing below them to intercept or filter the runoff and silt fence is shown in
proposed slopes. The Handbook wants the SF to be located at least 5’ beyond the base of
disturbed slopes.
E&SC measures have been revised to reflect the addition of the sediment basin and dry pond.
(Rev. 2) Comment addressed.
Revision 1 Comments:
2. Provide copies of all Army Corp permits related to the wetland disturbance.
Permits to be provided upon receipt.
(Rev. 2) Response noted.
We have included PDF copies of the plans and calculations for your review. If you have any
questions or comments, please feel free to give me a call at 434.295.5624.
Sincerely,
Andrew Allison, PE
Project Engineer