HomeMy WebLinkAboutWPO201100010 Review Comments Erosion Control Plan 2011-04-01ALg�,��
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COUNTY OF ALBEMARLE
Department of Community Development
401 McIntire Road
Charlottesville, Virginia 22902 -4596
Phone (434) 296 -5832 Fax (434) 972 -4126
Project: Old Trail Village — Block 23 ESC Plan [WPO- 2011 - 00010]
Plan preparer: Mr. Scott Collins, PE; Collins Engineering
Owner or rep.: March Mountain Properties LLC
Date received: 16 February 2011
Date of Comment: 1 April 2011
Engineer: Phil Custer
The Erosion & Sediment Control plan for Old Trail Village Block 23 (WPO- 2011 - 00010), received on 16
February 2011, has been reviewed. The plan can be approved after the following comments are addressed.
Inlet protection is not a sufficient primary measure for sediment control in Phase II of the ESC
plan. Inlet protection is intended as a supplemental measure with a sediment trapping measure
at the end of the pipe. Please modify the plan and construction sequence so that an
appropriately sized sediment trapping measure is provided at the end of pipe in phase 2 of the
ESC plan. The existing stormwater pond cannot be converted to an ESC basin. I recommend
moving sediment trap 1 (or perhaps combining both traps) 150ft to the west and rerouting the
storm pipe through this point. After the site is stabilized, this trap can be removed and a
riprapped channel to the pond can be constructed. Additional comments may be necessary
due to the required conceptual change.
The disturbance to the stream buffer appears to be unavoidable given the approved rezoning
plan and it will be authorized per 17- 321.6. However, this authorization will require an
approved and bonded mitigation plan, which can be easily accomplished between the existing
pond and units 6, 7, and 8. I also acknowledge that the redesign of the pipe system will
shorten the flow path for this pond. Since the site makes up such a small percentage of the
total watershed and the application plan only required Block 23 drain to a detention pond, a
shortened flow path will be allowed.
2. Please provide an approval letter from DEQ consenting to the proposed disturbance for the
construction of a storm pipe within their existing conservation easement. Also, the recorded
document referred to in the "existing drainage easement" note (DB 3745 PG 672) does not
delineate any drainage easement. This document appears to be solely concerned with water
and sewer easements.
3. Please show the grading and ESC measures necessary to connect the proposed sidewalk to the
existing sidewalk constructed with the road. This disturbance will also need to be authorized
by DEQ.
4. A soil map does not appear to have been provided.
5. The soil descriptions in the ESC narrative do not correspond to the soil types encountered on
this particular site. Please correct.
6. Please provide an updated list of the county's ESC notes on ESC -1. These can be found in the
latest edition of the design manual (updated 12 February 2010).
7. Please provide a location for a soil stockpile for the topsoil that will be removed at the
beginning of construction activities. The stockpile should be out of the way of general
construction activities.
8. Please provide outlet protection for all drainage system outfalls.
9. The area of disturbance stated in the ESC narrative does not match ESC -2 and ESC -3.
10. Please remove the previously approved SWM sheets from this set to avoid confusion in the
future. The Stormwater Runoff note on sheet ESC -1 should be updated to refer to the
application number of the previously approved plan that accounted for the detention of Block
23. A Pro -Rata share to the Lickinghole Basin will need to be paid as well. This fee will be
calculated at the time of plan approval.
11. Once all plans have been approved, please provide a completed Bond Estimate Request Form
to the county engineer to receive an ESC bond estimate.
File: El esc PBC WPO- 2011 -00010 Old Trail Block 23 ESC Plan.doc