20001195 Ver 6_Stormwater Approval_20081031

?O? W A T?90
Michael F. Easley, Governor
William G. Ross Jr., Secretary
North Carolina Department of Environment and Natural Resources
October 31, 2008
Charlotte Douglas International Airport
Attn: Mr. Jerry Orr, Airport Director
P.O. Box 19066
Charlotte, NC 28219
Coleen H. Sullins, Director
Division of Water Quality
DWQ EXP # 00-1195v6
Mecklenburg County
Subject Property: Charlotte-Douglas International Airport, Stormwater Management
Plan for Area West of 2"d Parallel Runway
APPROVAL OF STORM WATER MANAGEMENT PLAN (MODIFICATION)
Dear Mr. Orr:
On March 1, 2008, the Division of Water Quality (DWQ) issued a revised Water Quality Certification to
replace the Certification previously issued to you on July 28, 2006. As a result, a stormwater management
plan (SMP) application was submitted to the DWQ by your engineers Mr. Ron Geiger, PE and Ms. Jennie
Gende-Casanova of HDR Engineering, Inc. requesting a modification to the SMP dated March 15, 2007,
and approved by this office on March 22, 2007.
The DWQ has:reviewed the SMP received on September 22, 2008; with subsequent revisions received on
October 27, 2008 and October 30, 2008. This plan has been approved the DWQ and satisfies the
storrtnwater conditions required by the revised 401 Water Quality Certification issued on March 1, 2008.
You are required to meet the following conditions:
The stormwater treatment system consisting of the pavement vacuum sweeping (twice a week
minimum, prior to qualifying rain events, and after special events), grass swales, grass filter
strips, a bioretention cell, and extended dry detention basins, and the signed and notarized
Operation and Maintenance Agreements dated October 14, 2008, as approved by this Office, and
the drainage patterns depicted on the plan sheets, must be maintained in perpetuity. No changes to
the structural stormwater practices shall be made without written authorization from the Division
of Water Quality. All stormwater management conveyances, detention and treatment structures
shall have maintenance access and at least 10.00 feet drainage easements on each side to allow
for the ability to maintain the structures and to perform corrective actions.
2. DWQ considers the pavement and street vacuum sweeping to be a non-approved stormwater Best
Management Practice (BMP). Consequently,
a. Charlotte-Douglas International Airport will be responsible for conducting a monitoring
program, in consultations with the DWQ, to evaluate the effectiveness of this activity
according to recognized protocols;
b. The following activities, described in the operation and maintenance agreement
specifically for the pavement vacuum sweeping, shall be strictly adhered to. These
include, but are not limited to:
NorthCarolina
401 Oversight/ Express Review Permitting Unit ' aturallf
1650 Mail Service Center, Raleigh, North Carolina 27699-1650
2321 Crabtree Boulevard, Suite 250, Raleigh, North Carolina 27604
Phone: [phone] FAX [phone] Internet: http:l/h2o.enr.state.nc.us/ncwetlands
An Equal Opportunity/Affirmative Action Employer-50% Recycled/10% Post Consumer Paper
CDIA Mod. SWMP for Area West of 2nd Parallel Runway
Page 2 of 2
October 31, 2008
i. Sweeping all paved surfaces a minimum of twice a week, and after special
events/activities;
ii. Sweeping all paved surfaces prior to rain events greater than or equal to 1"
rainfall depth, irrespective of whether the pavement had been swept twice within
a week or not, if upon 24 hours notice that a qualifying rain event is imminent,
and if the pavement had not been swept within a twenty-four (24) hour period. A
qualifying rain event is one resulting in 1" or more rainfall depth as recorded by a
rain gauge;
Ili. Weekly trash and leaf litter pick up on all paved and adjacent grassed areas;
iv. Recording all rainfall events including dates and amounts with initials for rain
events 1" or greater to signify that pavement sweeping activity occurred prior to
the rainfall events;
v. Recording the dates and amounts of debris collected with dates initials.
c. Once a monitoring program is established, you are required to submit monitoring reports
along with rainfall and sweeping logs quarterly to the DWQ Express Review Program at
the letterhead address shown at the bottom of the first page, and also to the NCDENR-
DWQ Stormwater and General Permits Unit at:
NCDENR-DWQ
Stormwater and General Permits Unit
1617 Mail Service Center
Raleigh, NC 27699-1617
d. In the event that this stormwater treatment system does not meet a target performance
standard that would be agreed on in the monitoring program (either based on maximum
effluent TSS and nutrient limits (mg/L) at BMP discharge points, or minimum TSS and
nutrient removal rates), the Charlotte-Douglas International Airport will be required to re-
submit a stormwater management plan for re-approval by DWQ. This may include, but
is not limited to, incorporating other BMPs such as sand filter(s), bioretention cells and/or
extended dry detention basins in order to treat the stormwater runoff from areas where
vacuum sweeping is utilized.
3. The applicant and/or authorized agent shall contact the DWQ Express Review Program in writing
at the letterhead address within ten (10) days of the commencement of construction.
This letter completes the review of the Division of Water Quality under Section 401 of the-Clean Water
Act. If you have any questions, please contact Cyndi Karoly at 919.733.9721 or Joseph Gyamfi at
919.715.3473.
Since ly, ,
Cyndi B. Karoly, Supervisor
401 Oversight/Express Review Program
CBK/jg
cc: USACE Asheville Regulatory Field Office
DWQ Mooresville Regional Office
Bradley Bennett, DWQ Stormwater Permitting Unit
Matt Mathews, DWQ - Wetlands & Stormwater Branch
Ron Geiger, PE, HDR Engineering Inc., 128 S. Tryon St., Suite 1400, Charlotte, NC 28202
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