20140351 Ver 1_More Info Received_20140422

Homewood, Sue
From: Arrance, Keven <karrance @hazenandsawyercom>
Sent: Wednesday, April 23, 2014 8 54 AM
To: Homewood, Sue
Subject: DDWR# 140351 T Z Osborne 401 and Buffer Authorization
Attachments: Letter of No Practical Alternative-20140408 pdf
Good morning, Suel
It is my understanding that the City of Greensboro has contacted you relative to the buffer authorization and Letter of
No Practical Alternatives for the T Z Osborne Wastewater Treatment Plant expansion project (phase 3) for which you
have the Section 401 PCN application package Attached is a PDF of the letter Please let me know if you need me to
send you a hard copy instead
Have a great days
Keven Arrance
Principal Scientist I Hazen and Sawyer
4011 WestChase Blvd , Suite 500, Raleigh, NC 27607
919 863 -9350 (direct)
karrance(&hazenandsawyer com I hazenandsawyer com

HAMN AND MM"VER
Environmental Engineers & Scientists
April 8, 2014
Ms. Terri Aprile, Stormwater Engineering Specialist
City of Greensboro
Department of Water Resources
Post Office Box 3136
Greensboro, North Carolina 27402
Hazen and Sawyer, P C
4011 WestChase Blvd
Raleigh, NC 27607
919 - 833 -7152
Fax 919 - 833 -1828
Re. T Z Osborne Water Reclamation Facility 56 MGD Expansion — Package 3, City of
Greensboro, Guilford County, North Carolina
Dear Ms. Apple,
On behalf of the City of Greensboro Water Resource Department (WRD), Hazen and Sawyer is
requesting concurrence from the City of Greensboro with the determination that the proposed
project has no practical alternative relative to disturbance of protected riparian buffers. The
proposed project is located at WRD's existing T Z. Osborne Water Reclamation Facility (WRF).
One component of the proposed project is designed such that construction thereof will involve
disturbance of land within the protected riparian buffers.
WRD proposes to construct a new chlorine contact tank and associated cascade aerator and to
install a new 54" diameter effluent discharge pipeline. The proposed infrastructure is part of the
three -phase project to upgrade and expand the existing T.Z Osborne WRF. The expansion is
necessary in order to provide treatment capacity to accommodate the flows that have
historically been handled at the North Buffalo Creek WRF, which will be diverted_ in their entirety
to the T.Z Osborne WRF upon completion of the expansion and upgrades.
Installation of the new effluent discharge pipeline will necessitate that construction activities
occur within the protected riparian buffer area that extends 50 feet landward from top of bank
along South Buffalo Creek The encroachment into the riparian buffer area is unavoidable due
to the treated effluent being discharged directly into the stream The pipeline has been
designed to parallel the existing effluent discharge pipeline and will be located within the
existing, maintained grassy corridor associated with the existing effluent discharge line.
Measures to minimize disturbance and impacts to the riparian buffer area include evaluation of
alternate locations of the proposed effluent discharge pipeline and minimization of the extent of
limits of disturbance Alternate locations of the proposed pipeline would result in disturbance of
the protected riparian area, as the pipeline would discharge into South Buffalo Creek regardless
of its location Alternate pipeline alignments may have necessitated the removal of a significant
amount of woody vegetation A discharge location other than immediately adjacent to the
existing discharge would result in the need for additional impacts to the stream, its banks, and
its water quality due to the construction of a head and wing walls for the outlet of the pipe. In-
New York, NY - Armonk, NY - Woodbury, NY - Detroit, MI - Raleigh „NC - Charlotte, NC - Atlanta, GA - Fairfax, VA - Hollywood, FL - Boca Raton, FL 9 Fort Pierce, FL - Sarasota, FL 9 Miami, FL - Philadelphia, PA

City of Greensboro, Development Services
April 8, 2014
Page 2
stream work will be performed from within the area to be disturbed for installation of the pipeline
when possible in order to minimize impacts to the buffer area to the extent feasible
Best Management Practices (BMPs) will be implemented during construction to provide further
protection of water quality and of the riparian buffer areas The temporary BMPs that are
proposed for the project include silt fence with stabilized outlets, riprap for culvert inlet protection
and apron energy dissipation, yard inlet protection, tree protection fence, diversion swales, fiber
filtration tubes, and gravel construction entrances designed to trap dirt from vehicles and
equipment. Additionally, rolled erosion control matting (RECM) will be used to stabilize slopes
and line channels, silt bags for dewatermg, temporary slope drains, and temporary seeding will
be utilized as well.
Construction of the proposed project will result in temporary impacts to Zones 1 and 2 of the
protected riparian buffer adjacent to and abutting South Buffalo Creek The temporary impacts
consist of excavation for pipeline installation and modification of the existing head and wing
walls at the outlet of the existing and proposed discharge pipes Temporary impacts will occur
to 1,824 square feet of Zone 1 buffer and to 902 feet of Zone 2 buffer. The disturbed areas are
currently a maintained grassy pipeline corridor and will be reseeded with a native grass seed
mixture that is appropriate for the location and landscape position. Removal of woody
vegetation adjacent to the grassy corridor will be avoided if feasible. If the removal of woody
vegetation within the riparian buffer is determined to be necessary, the removed trees will be
replaced in -kind upon completion of final grading activities in the area Aboveground structures
or materials will be placed in the protected riparian buffer zones only if needed during
construction. No permanent, aboveground structures or materials are proposed within the
riparian buffer Riprap and the temporary cofferdam will not extend beyond the top of bank and
therefore will not encroach on the riparian buffer. No permanent impacts to the riparian buffer
are expected to occur as a result of implementation of the proposed project
A Pre - Construction Notification (PCN) application will be submitted to the United States Army
Corps of Engineers (USACE) and to the North Carolina Division of Water Resources (DWR) to
request authorization of proposed impacts to waters of the US The riparian buffer impacts will
be included on the PCN application to be reviewed by DWR. No mitigation for buffer impacts is
required as the work qualifies as an allowable activity
If you have any questions or require additional information, please contact me at 919 833 7152
Thank you for your assistance.
Sincerely,
HAZEN AND SAWYER, P.C.
TC-"' Linda Diebolt
Senior Principal Scientist
Attachments