NCC231211_ESC Approval Submitted_20230426

DURHAM
COUNTY Engineering and
EEO Environmental Services
LETTER OF APPROVAL
PROJECT NAME: Biogen Gene Therapy JOB NUMBER: 6362-10
SUBMITTED BY: Kimley Horn 9/3/21
NEW SUBMITTAL (X) REVISED ( ) ACRES: 21.0
October 5, 2021
Biogen US Corporation
225 Binney Street
Cambridge, MA 02142
Dear Sir or Madam:
This office has reviewed the subject Sedimentation and Erosion Control Permit
Application. We find the application to be acceptable and hereby issue this letter of
approval. If any stipulations or recommendations are applicable, a list is attached and is
incorporated as a part of this letter of approval. Pursuant to Section 3.8.5 of the Durham
City-County Unified Development Ordinance,plans for which no permit has been issued
shall expire one year from the approval date.
Please be advised that a copy of the approved plan must be on file at the job site, and a land
disturbing permit must be obtained and prominently displayed. Pursuant to G.S. 113A-61
(d) and Section 15.5.1 of the Durham City-County Unified Development Ordinance, you
are hereby notified that the Sedimentation and Erosion Control Office has the right to
inspect the site over the life of the project to insure compliance with the approved plan and
ordinance.
The Sedimentation and Erosion Control Program is performance oriented, requiring
protection of the natural resources and adjoining properties. If following the
commencement of this project it is determined that the sedimentation and erosion control
plan is inadequate to meet the requirements of the Durham City-County Unified
Development Ordinance, this office may require revisions in the plan and its
implementation to insure compliance with the Ordinance.

Pursuant to Section 12.10.6 of the Durham City-County Unified Development Ordinance,
prior to initiating land-disturbing activity, the person conducting such activity must notify
the sedimentation and erosion control office of the date that such activity will begin.
It should also be noted that approval of an erosion control plan does not in any way
indicate approval of, or authorization to begin installation of Stormwater
infrastructure without City/County approved Construction Drawings.
We look forward to working with you on this project.
Sincerely,
McKenzie Myers, PE
Stormwater Manager
CC: Emma Bowling
mg/jm
Rev.08/10

APPLICATION REVIEW COMMENTS
Project Name: Biogen Gene Therapy Job Number: 6362-10
Reviewed By: McKenzie Myers Approved (X)
1. Submit a Land Disturbing Permit fee in the amount of $16,800.00.
2. Contact the Durham City/County Planning Department and have themprovide
a Zoning Compliance Check off and an approved site plan to this office.
3. Upon installation of the tree protection fencing, submit a Tree Protection Fence
Certification Form and call this office for an inspection at(919) 560- 0735.
4. Submit a surety in the amount of$84,000.00.
5. Issuance of a Durham County Construction Stormwater Permit.
Please note,we no longer accept Cash sureties. See our web site for appropriate
Performance Bond or Letter of Credit forms.
Forms may be obtained from this office or from the Durham County Engineering website
at: http://dconc.gov/home.
Also available at the County website is a link to NCDEQ where information pertaining to the state
mandated Self Inspection Program and related forms can be downloaded. Please remember to
maintain your records!
NPDES:
Since this project will disturb one or more acres, stormwater runoff must be permitted pursuant to
the National Pollutant Discharge Elimination System(NPDES) administered in North Carolina by
the Division of Energy Mineral and Land Resources(DEMLR).You are responsible for complying
with the General Permit requirements and are subject to enforcement by DEMLR for any violations
of the General Permit. Enclosed is a copy of the General Stormwater Discharge Permit for
Construction Activities, NCG010000 covering your activity. The Permit will be considered valid
as long as your submitted plan meets the requirements of NCG010000. Further information
regarding the General Construction Permit introduced in August, 2011 can be obtained at:
http://portal.ncdenr.org/web/wq/ws/su/construction.