19930818 Ver 4_Modifications_20090914

Transmittal
Attention
To Ms. Cyndi Karo
e
HDR Engineering, Inc. 3733 National Drive Telephone:
Suite 207 919 785-1118
Raleigh, North Carolina h?j u I 1??
27612 9Np?N? Kq! ?f?©9
Date 09/14/09 Job No. ST?RzQah"
11 ?
NC DWQ R3-081% U q
Regarding South Wake Landfill, Permit Modification
We are sending you:
? Shop drawings
Z Copy of letter
X Attached
El Prints
? Change Order
El Under separate cover via the following items
E? Plans El I Samples ? I Specifications
El Other
Copies Date No. Description
9/11/09 Permit Modification Letter
These are transmitted as checked below:
Z For approval
El For your use
El As requested
El For review/comment
IQ I Forbids due
El Resubmit Copies for approval
El Submit Copies for distribution
E? Return corrected prints
l u l Prints returned after loan to us
Remarks AttacheNs the permit modification letter we discussed on the phone.
Feel free to cell if you have any questions. C9/ff -73,7- d?-.25,
El Approved as submitted
?1 Approved as noted
E?j Returned for corrections
El Other
19
Copy to I Signed G
If enclosures are not as noted please notify us at once John Jamison
? R3 -08k8 v?}
WAKTE Facilities Design
COUNTY
RO,? L Y
7 & Construction
September 11, 2009
US Army Corps of Engineers
Raleigh Regulatory Field Office
3331 Heritage Trade Drive, Suite 105
Wake Forest, North Carolina 27587
Attn: Mr. Jamie Shern
e64
9198566350
cl SF ? 119
19 8566355
?, I'009 "J, I
WaR Office Building. I? Floor
P.O. X50. Raleigh. NC 27602
Cy,
Subject: Request for Permit Modification
Section 404 Individual Permit, Section 401 Water Quality Certification
South Wake Municipal Solid Waste Landfill, Holly Springs, Wake County
Reference: USACE Action ID No. SAW-2006-20191-292, issued April 19, 2007
NCDWQ 401 Certification No. 1993-0818, issued April 9, 2007
Dear Mr. Shern:
The purpose of this letter is to request a modification to the individual permit for the above-
referenced project. This permit was granted April 19, 2007 to the Wake County Department of
Environmental Services to authorize the placement of fill material into 6.73-acres of
jurisdictional wetlands, 0.15-acre of non jurisdictional isolated wetlands, 2,561 linear feet of
stream having important aquatic functions, and 937 linear feet of streams evaluated as lacking
important aquatic functions (unimportant designation), associated with the construction of the
South Wake Municipal Solid Waste Landfill. The Landfill is currently under construction, with
Phase 1B being built along with the perimeter road along the north side of the Landfill. Phase
IA was constructed during 2007. The area of concern for this modification is the location of the
two stormwater basins on the north side of the Landfill.
The two intermittent stream drainages in question are (1) between the two northern stormwater
basins and (2) west of the western-most stormwater basin. A sediment basin and a sediment trap
were constructed in these intermittent stream drainages downgradient of the impact area of the
landfill. Figure 1 shows the locations of the sediment basin and sediment trap. Based on field
assessment and our September 2, 2009 meeting with DWQ, the sediment basin affected 227 feet
of unimportant intermittent stream channel, and the sediment trap affected approximately 40 feet
of unimportant intermittent stream channel, both of which do not appear to be covered in the
original permit.
The sediment trap involved excavating a small depression adjacent to the stream channel and
filling the stream channel just downstream with riprap to create a small rock check dam. The 40
feet of stream at the sediment trap is a temporary impact; fill will be removed, the small
excavation will be re-graded and stream banks will be stabilized.
The sediment basin was excavated/graded, leaving a generally flat, cleared '/z-acre area with the
stream channel still meandering through the middle of it. The graded area is currently vegetated
with a mix of grasses, sedges and weeds and is essentially dry throughout.
Based on our coordination with DWQ and the USACE, we anticipate no mitigation will be
required for either stream impact. This conclusion is based on a site visit with Lauren
Witherspoon of DWQ on September 2, 2009 and verbal discussions with USACE and DWQ
staff on September 3, 2009. The USACE agreed no mitigation was required and considered the
227 feet of stream to be an unimportant intermittent stream.
We therefore request a modification of the permit to include: 40 feet of temporary stream
impacts and an increase in permanent unimportant stream impacts to 1164 feet (1164 = 937+227
feet). Additionally, we hereby notify you that the contractor may need to utilize the area
impacted by the sediment basin to tie the two adjacent stormwater basins into one larger basin;
they have unexpectedly hit shallow bedrock during construction and the most cost-efficient and
lowest-impact option would be to form one basin over top of this sediment basin. This change
would not be detrimental to erosion control on-site and would help to minimize the need for
blasting and other more costly and invasive construction methods.
If you have any further questions concerning this request, please do not hesitate to contact me at
[phone] and by email at John.RobersonOwakegov.com, or John Jamison at HDR
Engineering at [phone] or John.Jamison,,hdrinc.com.
Sincerely,
4-
John Roberson, Project Manager
Wake County Facilities Design & Construction
cc: Cyndi Karoly, DWQ
Lauren Witherspoon, DWQ
Attachment
Page 2 of 2
I

N
PROPOSED
LIMITS OF
DISTURBANCE
PERENNIAL
STREAM
TEMPORARY SEDIMENT
TRAP (TO BE REMOVED)
ORIGINAL LIMITS
OF DISTURBANCE

22'71.,-" S,T M
IMP, CT'/

STORMWATER
E BASIN 3
C
(UNDER CONSTRUCTION)
1 5jR
\ \ D (vNID CON
ACCESS ROA SEDIMENT BASIN
It- IMPACT AREA
FaR

South Wake Municipal Solid Waste Landfill
Phase 1B Expansion
Scale: 1" = 100'
Permit Modification
09/09
1