20240530 Ver 1_01_EDurham_PCN Cover Letter_20240407

Kimley>»Horn
April 5, 2023
Ms. Julia Tillery
U.S. Army Corps of Engineers
Raleigh Regulatory Field Office
3331 Heritage Trade Drive, Suite 105
Wake Forest, NC 27587
Mr. Zach Thomas
NC Division of Water Resources
401 & Buffer Permitting Unit
512 North Salisbury Street
Raleigh, NC 27604
RE: Nationwide Permit 58 & Jordan Lake Riparian Buffer Authorization Application Package
East Durham Water, Sewer, and Stormwater Improvements Project — Phase 1A
SAW-2021-00103; NBRRO #21-012
City of Durham, Durham County, North Carolina
Dear Ms. Tillery and Mr. Thomas:
On behalf of our client, the City of Durham, Kimley-Horn is submitting the attached application for
authorization under Nationwide Permit (NWP) #58 and corresponding Individual 401 Water Quality
Certification for the East Durham Water, Sewer, and Stormwater Improvements Project — Phase 1 A in
Durham County, North Carolina. The East Durham Water, Sewer, and Stormwater Improvements
Project — Phase 1A is part of a multi -phase sewer, water, and stormwater infrastructure project
proposed by the City of Durham to replace and rehabilitate utilities in East Durham. The project is
situated north of Price Avenue, south of E. Umstead Street, west of S. Alston Avenue, and east of
Fayetteville Street in Durham, North Carolina. The project is proposed to address aging infrastructure
and inflow infiltration to the system, move the existing sewer lines away from streams, convert aerial
sewer crossings to subterranean crossings, move existing sewers out from under four homes, ensure
future capacity, and alleviate stormwater flooding in the area. Phase 1A of the East Durham Water,
Sewer, and Stormwater Improvements Project proposes to replace or rehabilitate approximately
3,200 linear feet of sewer line, 2,100 linear feet of water line, and 260 linear feet of stormwater line.
The area surrounding the project is largely urban, composed primarily of residential housing and
commercial development. The project area currently exists as a utility corridor running below existing
streets and along narrow riparian corridors in a primarily residential area.
A delineation of the existing Preliminary Jurisdictional Determination (PJD) limits was conducted by
Kimley-Horn staff on November 19, 2020, and two unnamed tributaries to Third Fork Creek (S1 and
S2) were identified. Final design of the proposed sewer improvements included small portions of
undeveloped area located outside the PJD boundary. Kimley-Horn conducted a site visit to assess
these additional areas on November 14, 2023, and identified no potentially jurisdictional features or

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riparian buffer zones. A PJD (SAW-2021-00103) was approved by April Norton of the USACE on
January 15, 2021. Additionally, a Surface Water and Buffer Determination Letter (NBRRO #21-012)
was approved by Stephanie Goss of NCDWR on March 12, 2021. The issued Surface Water and
Buffer Determination Letter and PJD for the project are attached as part of this permit application
package.
Due to limited depth beneath existing streams, trenchless crossings of streams will not be feasible.
The project proposes the installation of the utility lines underneath and alongside existing streams S1
and S2, which will result in unavoidable temporary and permanent stream impacts to the streams at
separate and distant crossings. The perpendicular utility crossings will be installed via open cut
trenching with a stream pump -around system to allow for temporary construction access and work in
the dry, resulting in a total of 172 LF (0.038 acre) of temporary stream impacts. The proposed utility
lines will be buried beneath the stream to not restrict flow and allow for movement of aquatic species.
Additionally, the stream banks will be stabilized with keyed -in rip rap at the locations of the
perpendicular utility crossings and armored along parallel runs near to the stream banks to protect the
banks and prevent future erosion, resulting in a total of 312 LF (0.072 acre) permanent stream
impacts with no net loss of waters across five separate and distant crossings along streams S1 and
S2. Upon completion of the project, temporary impacts will be returned to pre-existing conditions.
Installation of the utility lines and the associated permanent maintenance easements across and
alongside streams S1 and S2 will result in unavoidable permanent impacts to Jordan Lake Water
Supply riparian buffer zones. These permanent buffer impacts are broken into allowable uses and
allowable with mitigation uses. The installation of perpendicular non -electric utility lines and the
associated permanent easements across streams S1 and S2 will result in 22,443 square feet of
permanent Buffer Zone 1 impacts and 20,215 square feet of Buffer Zone 2 impacts. Installing the
non -electric utility lines and the associated easements parallel, along the streams will result in 7,503
square feet of permanent Buffer Zone 1 impacts, with no impacts to Buffer Zone 2. Temporary
impacts to Buffer Zone 1 and Buffer Zone 2 will result from temporary construction access and the
pump -around systems to allow for work in the dry to facilitate installation of the proposed utility lines
and removal of the existing utility lines beneath and adjacent to streams S1 and S2. Temporary
construction access will result in 9,023 square feet of temporary Buffer Zone 1 impacts and 2,924
square feet of temporary Buffer Zone 2 impacts. Temporary impacts will be restored to pre -
construction contours and re -vegetated with native species consistent with NCDWR riparian buffer
rules upon completion of the project as shown in the Planting Plan Set attached as part of this permit
application.
As a result of the critical infrastructure improvements associated with the project, new permanent
maintenance easements and utility crossings will be necessary within the protected Jordan Lake
Water Supply riparian buffer zones. In accordance with the Jordan Lake Water Supply Watershed
Buffer Rule, impacts resulting from impacts resulting from non -electric utilities other than
perpendicular crossings in Buffer Zone 1 require compensatory buffer mitigation. The City of Durham
has secured compensatory buffer mitigation at a 3:1 ratio for the 7,503 square feet of mitigatable
Buffer Zone 1 impacts to tributaries to Third Fork Creek (Streams S1 and S2). In total, the proposed
project will require 22,509 square feet of compensatory buffer mitigation credits. Therefore, to offset

Kimley>»Horn
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these riparian buffer losses, 22,509 square feet of compensatory buffer mitigation credits have been
reserved through the RestorEcology Jordan, LLC sponsored Bandit Farms Bank Site, and through
the Watershed Investments NC, LLC sponsored Neville Farms Phases 1 & 2 Nutrient Offset and
Buffer Mitigation Bank. The Statements of Availability from the mitigation banks have been included
as part of this application package.
To assist with the processing of this application, the following information is included:
• ePCN Application Form
• Signed Agent Authorization Form
• Figures
• Preliminary Jurisdictional Determination (SAW-2021-00103)
• Buffer Determination Letter (NBRRO #21-012)
• Mitigation Banks Statements of Availability
• Permit Drawings
• Plan Sheets
If there is any additional information you need to assist in the processing of this NWP application,
please do not hesitate to contact me at [phone] or [e-mail].
Sincerely,
Mackenzie Richards, PWS
Kimley-Horn & Associates, Inc.
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