20001195 Ver 12_More Info Letter_20120328

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RMENR
North Carolina Department of Environment and Natural Resources
Beverly Eaves Perdue
Governor
Mr Jerry Orr
Charlotte Douglas International Airport
Post Office Box 19066
Charlotte NC 28219
Division of Water Quality
Charles Wakild P E
Director
March 28 2012
Subject Property Charlotte - Douglas International Airport
UT to Coffey Creek [030834 11 137 4 C]
Dee Freeman
Secretary
DWQ Project # 00 1195v12
Mecklenburg County
REQUEST FOR MORE INFORMATION MODIFIED STORMWATER MANAGEMENT PLAN
Dear Mr Orr
On May 13 2010 the Division of Water Quality (DWQ) issued a revised 401 Water Quality Certification
to impact 1 148 acres of 404 Wetlands 21 669 linear feet of streams 7 522 acres of Open Water (ponds)
in order to expand the Charlotte Douglas International Airport Condition 10 of this certification requires
that a stormwater management plan be submitted to and approved by the DWQ
On December 12 2011 the DWQ received a stormwater management plan (dated November 21 2011)
for the West Boulevard relocation project from your consultant Mr Ronald Geiger PE of HDR On
March 5 2012 the DWQ received a revised stormwater management plan (dated March 1 2012) from
HDR The DWQ has reviewed the revised stormwater management plan and has found it to be
incomplete
Please provide the following information so that we may continue to review your project
Additioral Information Requested
Bioretention Cell #1
1 The bioretention cell is still sloped on the plan view of sheet 14A Bioretention cells must be flat
throughout their section to function properly
1617 Mad Service Center Raleigh North Carolina 27699 1617
Location 512 N Salisbury St Raleigh North Carolina 27604
Phone 919 - 807 -63001 FAX [phone] Customer Service 1- 877.623 6748
Internet www ncwatemuality oro
An EgLal Opportunity 1 Affirmah a Ach n Employer
NonrthCarolina
Naturally

Mr Jerry Orr
March 28 2012
Page 2 of 2
Both Bioretention Cells
1 The plans still show ponding of 18 Ponding shall not be greater than 12 Please revise
2 An original signed O &M Agreement form must be submitted Only a photocopy of the signature
page was submitted It can be downloaded from http Hportal ncdenr orojweb/wg/ws/su/bmp
ch12
3 The SHWT elevation determination should be based on a soil boring that looks for mottling of the
soil that results from mineral leaching The use of a piezometer for a single day will only provide
you with what elevation of the water table is on that given day not the seasonal high water table
elevation
4 Both supplements still incorrectly state that a vegetated filter step (VFS) is provided but there
are not any Note however that a properly designed VFS per chapter 8 of the BMP Manual is
not required for bioretention cells
5 Please be sure that any changes are consistently reflected on all documents (plans calcs and
forms)
Please submit this information or otherwise address this request within 30 calendar days of the date of this
letter Please call Mr Robert Patterson PE at [phone] if you have any questions regarding these
comments or would like to set up a meeting
Since;AA
QD14�
Annette Lucas PE
Wetlands Buffers and Stormwater Compliance and
Permitting (WeBSCaPe) Unit
AML /aml/rdp
cc U S Army Corps of Engineers Asheville Regulatory Field Office
Alan Johnson DWQ Mooresville Regional Office
Samar Bou ghazale DWQ Mooresville Regional Office
Michael Parker DWQ Mooresville Regional Office
Robert Patterson PE DWQ Stormwater Unit
File Copy
Ronald Geiger PE HDR 128 S Tryon St Suite 1400 Charlotte NC 28202 5004
Filename 001195vl2CharlotteDou„ IasinrlAimort(Mecklenburg)_SW_Mod_Hold2 docx