20081327 Ver 1_Other Agency Comments_20080828

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STATE OF NORTH CAROLINA
MICHAEL F EASLEY
GOVERNOR
August, 19, 2008
MEMORANDUM
To:
From:
Subject:
F&EM14
AUG 2 S 2008
DENR - WATER QUALITY
WETLANDS AND STORMWATER BRANCH
DEPARTN MNT OF TRANSPORTATION
Brian Wrenn, Transportation Permitting Unit,
NC Division of WaterQuality
Colin Mellor, LG, NCDOT Natural Environment Unit
LYNDO TIPPETT
SECRETARY
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TIP R-4430, WBS# 34623, Proposed widening of SRJ-793 v,,p????•?••?M'??v??`
(Upward Rd ), Henderson County P?Ajg*,P #?I,,IIIiia
NCDOT offer the following responses to the April 18, 2008 comments provided by
NCDWQ on the ICE Assessment for R-4430
1 NCDWQ expressed concern for the potential of acid drainage from potential rock
cuts both along the proposed roadway corridor and from development that may be
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 of iron sulfides and
therefore pose a high risk of generating acid runoff (Ashe 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 [15A NCAC 04B 0124(a)-(e)] 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
outlet 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 TELEPHONE [phone] or 919-715-1334 LOCATION
NC DEPARTMENT OF TRANSPORTATION FAX [phone] TRANSPORTATION BUILDING
PROJECT DEVELOPMENT AND ENVIRONMENTAL ANALYSIS 1 SOUTH WILMINGTON STREET
NATURAL ENVIRONMENT UNIT WEBS/TE www NCDOT ORG RALEIGH NC
1598 MAIL SERVICE CENTER
RALEIGH NC 27699-1598
Memorandum - NCDOT reply to NCDWQ's ICE comments
R4430 - Widening of Upward Rd, Henderson County
Page 2
is within the Bat Fork Creek watershed, minimizing clearing to less than 20 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 >5yr storm event) limited
the possible options for stormwater BMP's Options were presented at the 4(c)
review meeting on September 26, 2007 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 soil 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@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 Milrtscher, 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