HomeMy WebLinkAbout20041053 Ver 2_More Info Letter_20120214..
NC®ENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue
Governor
CERTIFIED MAIL 7009 2250 0004 3265 6681
RETURN RECEIPT REQUESTED
Mr Danny Rogers
City of Charlotte Charlotte Area Transit System
600 East Fourth Street
Charlotte NC 28202
Charles Wakild P E
Director
Dee Freeman
Secretary
February 14 2012
SUBJECT Proposed LYNX Blue Line Extension Northeast Corridor Light Rail Project from the
Terminal Station at the 7th Street Station to the Northeast to the University of North
Carolina at Charlotte (UNC Charlotte) Campus WBS #6 24 Mecklenburg County DWQ
No 04 1053 v 2
Dear Mr Rogers
The Division of Water Quality (DWQ) has reviewed your submittal for a 401 Water Quality Certification for the
aforementioned project A review of your request revealed it is lacking the necessary information required for
making an informed permit decision The permit application was deficient in the following areas
1 Provide stream flow direction arrows for all jurisdictional streams within the project limits
2 Clearly depict the proposed multi use path on all plan view drawings
3 Stream impacts of 396 linear feet (If) are proposed for Jurisdictional Stream D Figure 14 does not
depict where the flow from stream will be directed If the stream is being relocated to a stabilized
channel details for the channel must be provided to include a clear depiction on the plan view a detail
for the construction and the slope of the proposed channel (or profile drawing depicting the slope)
Additionally Figure 14 depicts rock check dams throughout the stream channel DWQ does not
authorize the installation of erosion control measures in active streams
4 Page 15 of the application indicates that the relocation of Jurisdictional Stream D will incorporate
natural stream channel design elements These elements were not provided in the drawings Provide
all appropriate stream relocation details
5 Figures 14 and 14a depict what appears to be a riprap pad at the end of a 72 RCP Figure 14a refers to
this impact as a rip rap stilling basin constructed of Class I riprap Please be advised that DWQ does
not authorize the construction of stilling basins in jurisdictional streams If the impact is associated with
a dissipator pad it must be labeled as such If a dissipator pad is proposed all riprap must be
embedded such that low flow of water and aquatic passage are unobstructed (i a embedded below the
streambed elevation) Additionally provide justification as part of the required avoidance and
minimization of impacts to jurisdictional resources for the riprap pad as the proposed slope of the 72
RCP is 0 60% (very flat)
6 Stream impacts of 80 If are proposed for Jurisdictional Stream C One 7x7 concrete box culvert will be
extended and two (2) 72 steel pipes will be installed to handle stormwater
Mooresville Regional Office
Location 610 East Center Ave Suite 301 Mooresville NC 28115
Phone (704) 66316991 Fax (704) 663 -60401 Customer Service 1- 877 - 623 -6748
Internet http llportal ncdenr orolwebtwQ
An Equal Opportunity 1 Affirmative Action Employer
NorthCarohna
NaturJ711Y
Mr Danny Rogers
Page Two
The existing 7x7 concrete box culvert is perched approximately 34 feet above the existing surface
water elevation and a very large scourhole exists at the end of the culvert Neither the application nor
Figure 14 or 14c depict any effort to provide stream connectivity as part of the culvert extension and
new pipe installation The plans do depict a nprap stilling basin with Class II nprap Figure 14c
depicts the outfall end of the stilling basin approximately 4 feet above the existing surface water level
As stated above DWQ does not authorize the installation of erosion control measures in jurisdictional
streams If a dissipator pad is proposed all nprap must be embedded such that low flow of water and
aquatic passage are unobstructed (i a embedded below the streambed elevation) Additionally the
applicant must investigate ways to restore stream connectivity These can include but may not be
limited to the construction of floodplain benches (and the subsequent restoration of the normal stream
dimension) at the outlet of the 2 72 steel pipes the installation of a function box at the end of the 7x7
concrete box culvert to lower the stream elevation and reduce stream and storm flow velocities inside
the structure rather than using the streambed and banks as dissipation devices and /or the construction
of a rock ladder
7 Stream impacts of 32 If are also proposed for Jurisdictional Stream C as part of the wastewater utility
line relocation DWQ is requesting that the applicant investigate opportunities to install an aerial
crossing or install the utility line subsurface so as to avoid direct impacts to the stream
8 A bridge crossing is proposed for Jurisdictional Stream F Provide a profile drawing depicting the bridge
support structures in relation to the stream and water surface elevation Typically bridge support
structures located on or near streambanks require scour protection If scour protection is required
details on the type of scour protection must be provided and any impacts associated with the scour
protection must be accounted for as a jurisdictional impact
9 Figure 15 depicts a high hazard temp silt fence along the top of the streambanks Please provide a
definition for high hazard temp silt fence It appears the fence is below the top of the streambank in
some locations Erosion control measures must be located outside jurisdictional areas
10 Figure 15 depicts what appears to be a nprap pad at the end of a 24 RCP The corner of the pad
appears to be on the top of the streambank Provide the slope of the 24 RCP and all details associated
with the nprap pad Provide information on how erosion will be prevented from stormwater discharging
from the pad as it appears to be discharging at the edge of the stream
11 Jurisdictional Stream J is proposed to be relocated to an 11x6 PBC Please define the acronym PBC
12 Figures 16 and 16a depict the installation of a rip rap stilling basin constructed of Class II nprap
Please be advised that DWQ does not authorize the construction of stilling basins in jurisdictional
streams If the impact is associated with a dissipator pad it must be labeled as such If a dissipator
pad is proposed all nprap must be embedded such that low flow of water and aquatic passage are
unobstructed (i a embedded below the streambed elevation) Additionally provide justification as part
of the required avoidance and minimization of impacts to jurisdictional resources for the nprap pad as
the proposed slope of the 11x6 PBC is 0 60% (very flat)
13 Provide information as to whether the width of the proposed culvert on Jurisdictional Stream J is 11 feet
or 6 feet The average normal channel width of the stream in the proposed impact area is
approximately 5 feet If the proposed culvert width is 11 feet provide information on how you propose
to maintain the normal stream dimension (approximately 5 feet) at the inlet and outlet ends of the
culvert
14 Figure 16 depicts a 15 RCP discharging to the 11x6 PBC which will be conveying Jurisdictional Stream
J Is the 15 RCP conveying stormwater directly to the stream? DWQ discourages the direct discharge
of stormwater to jurisdictional streams Provide information that the stormwater will be treated prior to
discharge (i a grassed swales) or why treatment is not feasible in this location
15 Provide the proposed pipe size (and flow direction) on Figure 17 This pipe will be conveying
Jurisdictional Stream N and water from Wetland Y
16 Figure 17 depicts a pipe north of Wetland Y that flows into the pipe which conveys Jurisdictional
Stream N Is this pipe existing or proposed? Is the pipe conveying stormwater directly to the pipe that
conveys Stream N?
Mr Danny Rogers
Page Three
DWQ discourages the direct discharge of stormwater to jurisdictional streams Provide information that
the stormwater will be treated prior to discharge (i a grassed swales) or why treatment is not feasible in
this location
17 Figure 18 depicts a nprap pad at the outlet of the proposed culvert on Jurisdictional Stream A
(perennial) No detail has been provided for the nprap pad The nprap pad is not depicted on profile
drawings Figure 18a and Figure 18b Additionally provide justification as part of the required
avoidance and minimization of impacts to jurisdictional resources for the nprap pad as the proposed
slope of the 11 x6 PBC is 0 69% (very flat)
18 Figure 18 depicts a nprap pad at the outlet of the proposed culvert on Jurisdictional Stream A
(intermittent) No detail has been provided for the nprap pad on the plan view drawing nor has a profile
drawing with the slope been provided for the 8 -6 PBC which appears to discharge to the nprap pad
Additionally provide justification as part of the required avoidance and minimization of impacts to
jurisdictional resources for the nprap pad (as well as the proposed slope)
19 Figure 18 does not clearly depict the impacts to Jurisdictional Stream A (intermittent) It appears that
the flow from Jurisdictional Stream A (intermittent) and Jurisdictional Wetland A is being split in a 8 6
PBC with some flow being directed to Jurisdictional Stream A (perennial) and some flow being directed
to drop inlet and some other unlabeled pipe Provide information why the flow is being split and where
the portion of flow that is directed to the drop inlet is ultimately being conveyed
20 Figure 18b depicts one of the two (2) — 72 steel pipes being installed at an elevation approximately
three (3) feet higher than the main /low flow pipe DWQ requests that the applicant investigate an
alternative method for discharging stormwater from the pipe rather than a three (3) foot drop down onto
nprap (if that is what is being proposed)
21 Stream impacts of 1 666 If are proposed for Jurisdictional Stream P Figure 19 does not depict where
the flow from stream will be directed If the stream is being relocated to a stabilized channel details
for the channel must be provided to include a clear depiction on the plan view a detail for the
construction and the slope of the proposed channel (or profile drawing depicting the slope)
22 Figure 19a depicts what appear to be two (2) 30 RCPs at the outlet of a 72 steel pipe Are these
pipes conveying stormwater directly to a stream? DWQ discourages the direct discharge of stormwater
to jurisdictional streams Provide information that the stormwater will be treated prior to discharge (i e
grassed swales) or why treatment is not feasible in this location
23 Stream impacts of 44 If are proposed for Jurisdictional Stream Z Figure 20 depicts this impact as what
appears to be an energy dissipator pad (unlabeled) and an unidentified shaded area of impact (no
explanation provided) Verify what the jurisdictional impact is and why it is necessary
24 Figure 20a refers to the nprap impact as a rip rap stilling basin constructed of Class II nprap Please
be advised that DWQ does not authorize the construction of stilling basins in jurisdictional streams If
the impact is associated with a dissipator pad it must be labeled as such If a dissipator pad is
proposed all nprap must be embedded such that low flow of water and aquatic passage are
unobstructed (i a embedded below the streambed elevation) Additionally provide justification as
part of the required avoidance and minimization of impacts to jurisdictional resources for the nprap pad
as the proposed slope of the 54 steel pipe (conveying an intermittent stream is 164%
25 Figure 20 depicts a culvert (unknown size) being plugged with flowable fill and abandoned Is this
culvert currently conveying Jurisdictional Stream Z*? If so it appears that some channel realignment
may be required to convey the stream at the outlet end of the new 54 steel pipe to the existing stream
channel If channel realignment is required a detail must be provided depicting the realignment
26 Figure 20 depicts what appears to be rock check dam in the jurisdictional stream DWQ does not
authorize the installation of erosion control measures in active streams
27 Figure 20 depicts an arrow with a label ( A21 8 D ) in Jurisdictional Stream Z No information is
provided for this label Additionally it appears some sort of easement is proposed for the stream as a
box with the label SIDE is located around a portion of the stream Provide information related to any
easements on the stream
Mr Danny Rogers
Page Four
28 Figure 21 depicts two (2) pipes with what appear to be dissipator pads at their outlets The pipes are a
30 RCP and a 60 RCP According to the scale provided the dissipator pad from the 60 RCP is
located approximately 20 feet from Jurisdictional Stream E Discharges from stormwater outfalls can
lead to stream and streambank destabilization Therefore provide details for both dissipator pads a
map depicting the topography of the area where the dissipator pads will be constructed (should be close
to flat) and the proposed slopes of the 30 and 60 RCPs
29 A bridge crossing is proposed for Jurisdictional Stream U Provide a profile drawing depicting the bridge
support structures in relation to the stream and water surface elevation Typically bridge support
structures located on or near streambanks require scour protection If scour protection is required
details on the type of scour protection must be provided and any impacts associated with the scour
protection must be accounted for as a jurisdictional impact
30 Provide a copy of the stormwater management plans for all proposed park and ride facilities
31 Page 18 of the application states that mitigation for stream impacts will be provided by the Charlotte
Umbrella Stream and Wetland Mitigation Bank (Umbrella Bank) It also states that the acceptance letter
F is included in Attachment E The letter provided in Attachment E states that The Umbrella Bank does
not currently have enough credits to cover this request however pending credit releases will
adequately cover the request DWQ will not issue a 401 Water Quality Certification authorizing stream
impacts without a letter from the Umbrella Bank and /or the Ecosystem Enhancement Program (EEP)
indicating that the required mitigation can be provided
32 Page 28 of the application indicates that heavy equipment will be prohibited from operating in the
stream channels without appropriate measures Please be advised that DWQ prohibits the use of
heavy equipment in stream channels without prior authorization
Therefore pursuant to 15A NCAC 2H 0507(a)(5) we will have to place the permit modification request on hold
until we are supplied with the necessary information You have 21 days to respond in writing with the requested
information or notification to this office that the information is forthcoming If at the end of the 21 days this
office has not received this information in writing we will assume you are withdrawing your application and it will
be returned Furthermore until the information is received by the NC Division of Water Quality we request by
copy of this letter that the US Army Corps of Engineers place the permit modification request on hold If you
have any questions or require additional information please contact Polly Lespmasse at (704) 663 1699
Sincerely
,—a, 19
for Charles Wakild P E
Director
cc Amanda Jones US Army Corps of Engineers Asheville Field Office
Michael lagnocco STV /Ralph Whitehead Associates
Brandon Phillips STV /Ralph Whitehead Associates
Karen Higgins NCDWQ Wetlands Buffers Stormwater Compliance /Permitting Unit
Sonia Carrillo NCDWQ Transportation Permitting Unit
File Copy