20110119 Ver 1_More Info Received_20110311

:yam
March 10, 2011
Steve Chapin
U.S. Army Corps of Engineers D
Asheville Field Office?
151 Patton Avenue, Room 208
1
Asheville, North Carolina 28801-5006 MAR 20 11
Alan Johnson ?ENR - TAc"-1
401 /Wetlands Unit Wedaneb & ?1 ranch
1650 Mail Service Center
Raleigh, NC 27699-1650
RE: High Shoals Sewer Interconnect (DWQ #11-0119)
Addendum to Nationwide Permit No. 12/401 Water Quality Certification No. 3,689 Request
Gaston County, North Carolina
Dear Gentleman:
HEIR Engineering, Inc. of the Carolinas (HDR), on behalf of Gaston County (County), requests an
addendum to "the Nationwide Permit No. 12/401 Water Quality Certification No. 3689 application
submitted for the High Shoals Interconnect project (dated January 31, 2011). The County proposes to
replace a previously unpermitted culvert on private property over a perennial unnamed tributary to the
South Fork Catawba River. The culvert will be used as a permanent stream crossing for the sewer line
construction and maintenance access. The existing culvert will be repositioned to allow for better
connectivity between the upstream and downstream portion of stream channel. The culvert bottom shall
be buried at least one foot below the normal bed elevation to provide safe passage of fish and other
aquatic organisms during drought or low flow conditions. The eroded stream bank immediately
downstream of the existing culvert will be sloped to a 2:1 ratio, seeded, mulched, and matted with
biodegradable fabric. The culvert replacement will result in approximately 40 linear feet of additional
permanent fill impacts.
Enclosed are a location map, revised stream impact table, culvert detail, and site photographs.
Thank you in advance for your assistance: Please contact me at [phone] or
[e-mail] if you have any questions or require additional information.
Sincerely,
Eric Mularski
Environmental Scientist
440 S Church Street Phone: [phone]
HDR Engineering, Inc. of the Carolinas Suite 1000 Fax: [phone]
Charlotte, NC 28202-1919 www.hdrinc.corn
CC. Mr. Ray Maxwell, Public Works Director, Gaston County
Ms. Mary Knosby, Project Manager, HDR
Mr. Matthew Shultz, Project Manager, HDR
HDR Engineering, Inc. at the Carolinas
3a. 3b. 3c. 3d. 3e. 3f. 3g.
Stream impact Type of Stream Name Perennial Type of Average Impact
number- impact (PER) or jurisdiction stream length
Permanent (P) intermittent (Corps -404, width (linear
or Temporary (INT)? 10 DWQ - (feet) feet)
(T) non-404,
other)
S 1 (P/T) Rip-rap Little Long PER Corps 20-25 10 (P)
Creek SN 30 (T)
S2 (P/T) Rip-rap UT to South INT Corps 6-7 10 (P)
Fork (SI) 30 (T
S3 (P/T) Rip-rap UT to South INT Corps 6-8 10 (P)
Fork SD 30 T
S4 (P/T) Rip-rap UT to South INT Corps 15 10 (P)
Fork SC 30 T)
S5 (P/T) Rip-rap UT to South PER Corps 8-10 10 (P)
Fork SM 30 T)
S6 (P/T) Rip-rap UT to South PER Corps 6-8 10 (P)
- Fork (SL) 30 (T)
S7 (P/T) Rip-rap UT to South
Fork (SE) PER Corps 8-10 10 (P)
30 (T)
S8 (P/T) Rip-rap UT to South PER Corps 8-10 10 (P)
Fork (SE) 30 (T)
S9 (P/T) Rip-rap UT to South
Fork (SE) PER Corps 8-10 10 (P)
30 (T)
S10 (P/T) Rip-rap UT to South
Fork PER Corps 12-15 40 (P)
3h. Total stream and tributary impacts 130 (P)
270 T
N
N
N
N
m
TIE TO EXISTING STREAM
BANK STABILIZATION
EXISTING 30 LF
OF 60" CMP
CULVERT PIPE ?'t tt
. t
t t
t t
t :
t t
t t
i
EXISTING STREAM CENTERLINE
PLAN
EXISTING DIRT DRIVEWAY
2:1 SLOPE AND INSTALL
EROSION CONTROL MATTING
EXISTING STREAM BED
1-11111- -
EXISTTNG STREAM BED
RE-INSTALL EXISTING CULVE
PIPE TO ALIGN WITH EXISTIN
STREAM CHANNEL. BURY PIPE
SO THAT BOTH UPSTREAM
DOWNSTREAM INVERTS ARE
1-FOOT BELOW STREAM BED.
SECTION
FaR
HDR Engineering, Inc.
of the Carolinas

10 LF OF RIP RAP APRON.
EXTEND RIPRAP UP TO
CENTERLINE OF PIPE ON EACH
SIDE
CULVERT PIPE RE-INSTALLMENT
GASTON COUNTY - HIGH SHOALS SEWER INTERCONNECT
10 LF OF RIPRAP APRON
RE-INSTALL EXISTING PIPE
TO ALIGN WITH EXISTING
STREAM CHANNEL
NOTE:
EXISTING DIRT DRIVEWAY
REPAIR DOWNSTREAM BANK BELOW PLUNGE
POOL USING 2:1 SIDE SLOPES AND INSTALL
EROSION CONTROL MATTING PER THE
SPECIFICATIONS.
DATE
03/08/11
FIGURE
Figure 1
Proposed High Shoals Interconnect Alignment
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h a '1`j •� y.
PID 169441 ,
Culvert Re -Installment
,� ~ • - 40 LF of Permanent Impacts
NP
;701 + l •� t�g�' " r
s' alias
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1 inch = 2,000 feet
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Feet • ;r ` � ��•
0 1,000 2,000 4,000 le`` • y
Gastonia North and Mount Helly L1SGS Duadrannlps
ftJ ` Culvert Re -Installment
ONE COMPANY', Many Solutions -
Gaston County I High Shoals Interconnect Project I Nationwide Permit 12

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ONE COMPANY I ,Vn„ Saba-- Site Photoqraphs - Hiqh Shoals Sewer Interconnect

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