20081327 Ver 1_Other Agency Comments_20080819

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MtCHAEL F. EASLEY
GOVEIt;YOR
August, 19, 2008
MEMORANDUM
To:
Frain:
Subject:
STATE OF NORTH CAROLINA
UEPARTI~~1T ~F TRANSPUR.TATION
Brian Wrenn, Transportation Permitting Unit,
NC Division of WaterQuality
Colin Mellor, LG, NCD(7T Natural Environment
LYNDO TIPPETT
SECRETARX
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TIP R-4430, WBS# 34623, Proposed widening of SR 1793 ~i,~~'p~ j~ ~ ~~~,``~~•`
(Upward Rd.), Henderson County h,+~~re~t~ct4~~r`
NCDOT offer the following responses to the April 18, 2008 comments provided by
NCDWQ on the ICE Assessment for R-4~13p:
1. NCDWQ expressed concern for the potential of acid drainage from potential rock
cuts both along the proposed roadway corridor and from development that maybe
stimulated by the proposed project.
No cuts within rock are proposed along the roadway alignment. Within
Henderson County, the geologic formations known by the North Carolina
Geologic Survey (NCGS) to contain significant amounts ofiron sulfides and
therefore pose a high risk of generating acid runoff (Ache Metamorphic
Suite/Tallulah Falls Formation), occur in the north-western third of the county. A
literature and mapping search, as well as a field outcrop investigation, confirm
that neither of these geologic units underlies either the roadway project or the ICE
Growth Impact Study Area.
2, NCDWQ requested that the NCDOT implement Design Standards in Sensitive
Watersheds [l~A NCAC 04B .0124(x)-(e)J for the portions of the corridor
draining to Bat Fork Creek and that NCDOT implement stormwater BMP's that
route runoff from the road project through vegetated conveyances with reduced
Qutlet velocities.
Section (a) of the design standards refers to limiting uncovered areas in High
Quality Water Zones to 20 acres or less. Due to the length of the project area that
MAILING ADDRESS: TELEPNONE: 819-715-1335 or 919-715-1334 LOCATION:
NC DEPARTMENT OF TRANSPORTATION FAX: [phone]{)1 TRANSPORTATPON BUILDING
PROJECT DEVELOPMENT AND ENVIRONMENTAL ANALYSIS 1 SOUTH W ILMYNGTON STREET
NATURAL ENVIRONMENT UNR WEBSITE: WWW.NCDOT.oRC RALEGH NC
1598 MAIL SERVICE CENTER
RALEIGH NC 27$99-1588

Memorandum - NCD4T reply to NCDWQ's ICE comments
R-443Q -Widening; of Upward Rd., Henderson County
Page 2
is within the Bat Fork Creek watershed, minimizing clearing to less than 2U acres
will severely limit construction schedule. NCDOT has previously been given
permission by NCDWQ to waive this provision and we ask for that opportunity
on this project. Sections (b) - (d) address stormwater and erosion controls. As
part of NCDOT's merger process, stormwater and erosion control issues along the
project. have been discussed in order to avoid and minimize the direct impacts of
the project. Given that this is a widening project, spatial restrictions, and existing
conditions (primarily backwater from Bat Fork Ck. in >Syr, storm event) limited
the possible options for stormwater BMP's. Options were presented at the 4(c}
review meeting on September 26, 2UU7. In the vicinity of Bat Fork Creek,
NCDOT proposes to implement a preformed scour hole and a specially designed,
wide bottomed ditch. The ditch will have rock checks to reduce outlet velocities
and improve sediment removal. Additionally, a sail mat will be incorporated with
the rock checks that could provide some infiltration. Section (e) of the design
standards requires groundcover sufficient to restrain erosion to be provided within
15 working days or 60 calendar days (whichever is shorter) after completion of
construction. NCDOT agrees to this provision in riparian areas or near creeks that
drain into Bat Fork Creek.
We appreciate NCDWQ's input on this project. If there are any questions, please
call (919-'715-1426) or email (cmellor c~ncdot.gov ).
cc: Dave Baker, US Army Corps of Engineers, Ashville Field Office
Clarence Coleman, Federal Highway Administration
Roger Bryan, Division 13 Environmental Officer
Chris Militscher, Environmental Protection Agency
Marla Chambers, NC Wildlife Resources Commission
Mike Parker, DWQ Asheville Regional Office
Mark Staley, NCDOT Roadside Environmental
Jeff Hemphill, NCDOT Natural Environment Unit