HomeMy WebLinkAboutWPO202100033 Correspondence 2022-09-26i
o BIaCkWell Engineering, PLC
566 East Market St. - Harrisonburg, Virginia 22801 - (540) 432.9555 - www.BlackwellEngineering.wm
9/23/2022
Emily Cox
Civil Engineer II
401 McIntire Road, North Wing
Charlottesville, VA
Response to County revision letter- Troxell Poultry House
Dear Ms. Cox:
The following changes and/or clarifications have been made in response to your comment letter dated
9/21/2021. Please see our responses below in red.
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. Please provide an updated SWPPP with the latest plans.
Updated SWPPP has been provided.
B. Pollution Prevention Plan (PPP)
The PPP content requirements can be found in County Code section 17-404.
1. Ensure the PPP in the SWPPP is project specific and is updated with the latest plan.
The only change to the site plan is to replace the pond outlet pipe with a ditch, so there are no
changes to the PPP in the SWPPP.
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. Please show the total limits of disturbance on the plans. Has it changed with this revision? If
so, please provide an updated registration statement with new area.
Sheet 2 has been zoomed out to show total disturbed area. Leader labeling disturbed area has
been added to sheet 1. No change of acreage has occurred.
2. Please label the cover sheet as WPO202100033 - Amendment 1.
Cover Sheet has been updated.
3. Please specify the EC-1 for each ditch in chart shown (rip -rap is shown at beginning and
end, but not for each ditch section):
Liner was erroneously labeled. It should have been labeled as VDOT EC-2 Type-1 or E&S-C
Treatment-1. Table has been updated.
4. Why are there two 20'- 24" pipes in the channels? Please explain. It is unclear if the
calculations for these are in the engineering manual. Also, ditch A, B, C do not appear in
engineering manual. Please clarify and ensure all labels match on the plan and the calculations.
The culverts are for the crossing of farm equipment. This has been added to culvert callout on
sheet 2. A culvert cross section for the downstream most culvert is provided on p 161 of the
engineering manual. The 10 year storm event from p. 115 was used for these calculations.
Ditches A, B, & C were labeled in the calcs as 'Proposed Pond Outlet," "Proposed to EB#1," and
Proposed to Point B." Cross section calculations have been relabeled to match labeling on plans.
Hydrograph names do not allow enough characters for renaming, so references to accompanying
hydrographs have been added to sheet 2 of the plans as well as the cross-section calculations.
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 E&S perimeter controls for construction of the ditch.
Silt fence has been added around the outlet protection and check dams have been added inside
the ditch to provide E&S protection until the ditch is lined and seeded. Additional inlet/outlet
protection around the crossing culverts will additionally add erosion protection.
Thank you. Please let me know if you have any questions or need additional information during your
review.
Respectfully,
Brian Kinzie