HomeMy WebLinkAboutWPO202100033 Correspondence 2021-07-07i
o BIaCkWell Engineering, PLC
566 East Market St. - Harrisonburg, Virginia 22801 - (540) 432.9555 - www.BlackwellEngineering.wm
7/6/2021
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
6/29/2021. 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 use Albemarle County SWPPP template:
https://www.a lbemarle.org/home/showpublisheddocument/166/637202310327530000
Albemarle SWPPP format has been used.
2. Ensure registration statement and section 9, signed certification are signed.
Both have been signed and included.
B. Pollution Prevention Plan (PPP)
The PPP content requirements can be found in County Code section 17-404.
1. Please provide a PPP. See 17-404 for required contents:
https://mcclibrary.blob.core.usgovcloudapi.net/codecontent/l2230/385730/Cha pter%2017%2
0 Water%20 Protection.pdf.
PPP is provided in SWPPP.
C. Stormwater Management Plan (SWMP)
1. A stormwater management maintenance agreement must be recorded before this plan can
be approved. Please contact Ana Kilmer [akilmer@albemarle.org 434-296-5832 ext.3246] to
complete this process.
Noted. Client has been notified to contact Ana Kilmer to begin process.
2. Since forest & open space is being used in the VRRM, this area must be shown on a plat
labeled as SWM forest & open space and recorded with a deed before this plan can be
approved. There must also be an easement labeled SWIM Facility easement around the
proposed pond and its outfall and access area. The easement plat application can be found
here: https://www.albemarle.org/home/showdocument?id=1052
Plat to be submitted once all revisions to plan are approved and final boundaries are set.
3. Please add the following note to this plan and the plat mentioned in the above comment:
"The SWM Forest and Open Space Easement is subject to the guidance set forth by DEQ in the
Virginia Stormwater Management Program. The areas will remain undisturbed in a natural,
vegetated state, except for activities as approved by the local program authority, such as
forest management, control of invasive species, replanting and revegetating, passive
recreation (e.g., trails), and limited bush hogging to maintain desired vegetative community
(but no more than four times a year)."
Note has been added to sheet 2 under the legend in the "Water Quality Master Plan" Viewport
4. Please clarify where the 17.5 acres of forest & open space is located. The legend appears
incorrect on sheet 2.
Cross hatched area represents open space. Legend has been corrected.
5. Please add a title to sheet 1 and include WPO202100033 in the title.
Title has been added.
6. Professional seal should be signed and dated.
All sheets have been signed and dated.
7. Please provide date the topographic information was obtained/survey was completed.
Date of survey has been added to "Extra Note 2" (now located at the bottom of sheet 1).
8. Please show the WPO buffer and any critical slopes from county GIS on all applicable sheets.
GIS overlay has been added to the 3 drainage map viewports on the top half of sheet 2. No
WPO buffer or critical slopes lay withing the disturbed area of the site.
9. It would be helpful to have a grading and layout sheet separate from the E&S sheet.
Grading has remained on sheet 1 while E&S is now shown on sheet 3.
10. Please double check all grading and contour labels. The northern end of the site appears
to have 1 ft contours tying in to 2 ft contours. Also, the proposed contours do not match the
labels on the northwest side of the site.
Proposed contour labels were in error and have been remedied. Grading/contour labels have
been checked and are accurate.
11. Is the disturbed area 7.65 acres or 7.71 acres? There is a discrepancy in the plans.
New proposed disturbed area is 7.90 acres. "Property Info' box on sheet 1 and "Water Quality
Master Plan" viewport have been updated.
12. Please label contour elevations on all applicable sheets, especially the drainage divides.
Contour labels have been added to all the Drainage Map viewports.
13. Please list the required maintenance for the proposed SWIM pond on the plans.
Pond Maintenance table has been added to sheet 4 of the plans.
14. Please provide the following as -built check list on the plans:
https://www.albemarle.org/home/showpublisheddocument/3381 /637327510536700000
Detail has been added to sheet 4 of the plans.
15.On page 5 of your calculations packet, please clarify that you are meeting flood protection
by 9VAC25-870-66-C2B (it appears you were missing the C).
That is correct. The narrative has been updated. [Print New narrative].
16. Please provide a detail for the emergency spillway for the permanent dry pond.
Emergency spillway detail has been added to sheet 3.
17. Per 9VAC25-870-66-B, concentrated stormwater flow shall be released into a stormwater
conveyance system. The currently proposed outfall does not appear to go into a conveyance
system or channel.
Pond enters into a natural swale. Low point of swale, along with accompanying drainage areas
have been added to the "Proposed Drainage Areas" viewport on sheet 2. Accompanying TC
and Flow calcs have been added to the manual and show the swale is an adequate channel to
convey the post development flow.
D. Erosion and Sediment Control Plan (ESCP)
1. Please provide the paved CE with wash rack detail from the Albemarle County Design
Standards Manual (page 8): https://www.albemarle.org/Home/ShowDocument?id=270
Detail has been added to sheet 4.
2. Please show dust control as an E&S measure.
Dust control has been added.
3. Please show a stockpile, staging and parking area.
Stockpiles are shown on the ESC page (now sheet 3) and have been labeled. Staging and
parking areas are also now shown.
4. Please provide adequate perimeter control, including silt fence around the southern and
eastern ends of the project.
Silt fence has been added along the south/eastern portions of the site.
5. Ensure Albemarle County Standard Notes are on the plan:
https://www.albemarle.org/home/showpublisheddocument/l262/637321325255330000
Standard notes have been added to sheet 4 of the plans.
6. Provide details for the trash rack and anti -seep collars.
Details have been added to sheet 4 and sediment basin detail on sheet 3 references the added
details.
7. Please clearly show the drainage area for the sediment basin as well as the required dry and
wet volume storages.
Drainage area for Basin is shown on sheet 2 in the "ESC Drainage Areas" Viewport." Wet and
dry storage volumes have been added to the sediment basin detail on sheet 3.
8. Please add a note to the plans that County Inspector may require additional measures as
needed on site.
Note has been added beneath the Legend on Sheet 3.
Thank you. Please let me know if you have any questions or need additional information during your
review.
Respectfully,
Brian Kinzie