20140608 Ver 1_Emails_20140728 (2)

Cranford, Chuck
From: Dale Pennell <Dale .Pennell @Mcgillengineers.Com>
Sent: Friday, July 25, 2014 6:28 PM
To: david.w.brown @usace.army.miI
Cc: Cranford, Chuck; bryan_tompkins @fws.gov; Greg Hoffman; Royster, Preston B
Subject: PCN review for Big Hungry Upper Dam Removal Project
Attachments: Big Hungry Dam Sediment Sampling Report.pdf
David,
Thank you for your preliminary review of our PCN submittal. I have reviewed your comments, and offer the following
responses below in red.
At your convenience, I would be happy to meet with you and go over these responses, or any other questions you may
have, in order to keep the permitting process moving.
Thanks,
Dale Pennell, PE, PLS
McGill A wte rat..
UJ
X
ENGINEERING &
McGill Associates, P.A.
55 Broad Street I Asheville, NC 28801
Phone: [phone] Mobile: [phone] Fax: [phone]
Email: dale .pennell @mcgillengineers.com I Website: www.mcgillengineers.com
From: Brown, David W SAW [ mailto :David.W.Brown @usace.army.mil]
Sent: Wednesday, June 18, 2014 8:55 AM
To: Dale Pennell
Cc: Cranford, Chuck; Tompkins, Bryan
Subject: Request for Additional Information (UNCLASSIFIED)
Classification: UNCLASSIFIED
Caveats: NONE
McGill Associates
Asheville, NC 28802
Mr. Dale Pennell,
1

The Corps has received and reviewed your recently submitted Pre - Construction Notification
(PCN) application and supporting documents (dated June 13) for the Big Hungry River Upper Dam
Removal Project located in the Upward Community, Henderson County North Carolina. After
review and evaluation of the submitted documents the Corps is requesting the following
additional information in order for us to consider the application complete.
1. The PCN indicates permanent impacts to streams and wetlands for construction of the access
road. These impacts do not meet the conditions of Nationwide Permit (NWP) 33 for Temporary
Construction, Access, and Dewatering activities. Please specify the NWP number you propose
these impacts to be verified under. If the impacts for the access road are to total less
than 25 cubic yards of placement of fill material into the streams and wetlands, then NWP 18
can be used, if more than 25 cubic yards is proposed, than NWPs 39 or 42 may be utilized. It
is our intent to limit the total impact to streams during access road construction to less
than 25 cubic yards; therefore NWP 18 will apply.
2. The PCN states a temporary sand bag berm and diversion piping will be placed in the Big
Hungry River during dam removal activities in order for work to be conducted in the
dry. This temporary impact is not shown Part C, section 3 of the PCN (page 4). The PCN will
be revised to include 700 LF of temporary impact to the Big Hungry River consisting of
temporary piping and sand bag berm.
3. Location of permanent wetland impact W1 on access road. This impact is at stream S1,
where a seep spreads across the existing forest road before it runs over the road's edge. We
will be collecting this seep into a pipe at S1 and therefore eliminating the wet road
area. We will revise our plans to show impact W1 on sheet C -101.
4. How is access to /along the Big Hungry River to be obtained for stream restoration and
sediment removal activities? The majority of the river bed area from river station 13 +00 (at
the dam) to station 4 +00 will be excavated to remove accumulated sediment and to restore the
river channel. From station 4 +00 to 0 +00, we have shown a 12' haul road to move material to
the access road and then to the sediment disposal area. At the dam, the elevation of the
river bed is nearly equal to the top of the concrete dam, so accessing the dam for demolition
or the upstream river banks for sediment removal will not be an issue. As sediment removal
and demolition continues, the trucks will be able to use the remaining areas where sediment
has accumulated to reach the haul road and access road.
5. Sheet C -104 shows a 12 -foot wide haul road for sediment removal along the river. Where is
this road located on sheets C -102 and C -103? The road is not shown on C -102 or C -103, as
this area is where the main accumulation of sediment in the former lake bed is located and
the stream restoration takes place. The contractor will be using the exposed sediment areas
to drive trucks and carry excavated sediment to the disposal area. Are there impacts to
jurisdictional streams or wetlands associated with this road? Based on our observations,
Sheet C -103 shows drainage paths below impacts S -3 and S -4 on the access road. These
drainage paths, indicated by the contours, lead to a low area above the haul road, where any
flowing water seems to disappear into the ground. We have never seen any flowing water
crossing the haul road location during our visits.
6. Are there impacts to jurisdictional streams or wetlands associated with the proposed 6-
foot wide river access trail? We have found no wetlands or streams in the area of the
proposed trail, as this entire area is within the former lake bed that is now filled with
sediment.
7. An endangered plant is noted on CE -103 and C -103. What is this plant? During a site
visit with staff from the Natural Heritage Program, they identified this one spot as
containing Dwarf - flowered Heart Ieaf (Hexostylis noniflora). They specifically asked us not to identify this
plant on our drawings in order to prevent possible plant vandalism or theft. If this is a
federally listed species, have efforts to minimize or avoid impacts /affects to this plant

been coordinated with U.S. Fish and Wildlife Service (USFWS)? It is our understanding that
NHP staff may attempt to move and /or relocate this small area of plants (possibly 2 or 3
plants) prior to construction, in coordination with NCWRC staff.
8. Based upon information submitted, the proposed activities may require verification under
NWP 16 for return water from upland contained disposal areas. The return water from a
contained disposal area is administratively defined as a discharge of dredge material, even
though the disposal itself occurs in an area that has no waters of the U.S. (WoUS) and does
not require a section 404 permit. This NWP satisfies the requirement for a section 404
permit for return water where quality of the return water is controlled by the State through
the section 401 certification procedure. Provide details of how the return water will be
managed. It is our intention that the dewatering of the work area through use of the bypass
piping will yield a relatively dry sediment material which will be transported to the
disposal area. Therefore, we anticipate no "return water" from the disposal area. We have,
however, planned for a bottom drain in the disposal area to allow rain water which falls to
drain from the area and into the adjoining woods. In our opinion, return water would be
defined as water that drains out of the removed sediment once it is placed in the disposal
whereas rain water falling on the dry sediment would be considered runoff. If my
understanding of the return water definition is incorrect, we will revised our PCN
accordingly.
9. Provide a stream restoration plan for the Big Hungry River in the project area. This plan
shall contain details for stream structures, bank stabilization measures, buffer and riparian
zone planting measures, channel stabilization specifications, habitat elements, plans to
return stream bed and banks to natural elevations, and a post - project monitoring plan for the
restored stream area including the areas downstream for stability, sediment transport,
habitat impacts, and water quality effects. The stream restoration plan is shown on Sheets
C -504, and sheets 1 and 2 provided by S &ME. We have not prepared a post - project monitoring
plan.
10. What measures have been or will be taken to determine the presence of pollutants in the sediments located
in the historic /current impounded area? At the beginning of this project, we retained S &ME to perform
contaminant testing on a representative sampling of the accumulated sediment within the river. Their
September 19, 2012 report is attached. If pollutants are present, what measures will be taken to minimize
mobilization and impacts of these constituents to the environment? The report states: Each of the analyzed metals
was detected in the composite samples. Due to the undefined source of potential sediment contamination, the Inactive
Hazardous Sites Branch (IHSB) Preliminary Residential Health -Based Soil Remediation Goals (SRGs) were used for
comparison purposes. Arsenic was detected in each of the four composite sediment samples at concentrations exceeding
the IHSB Preliminary Residential Health -Based SRGs but less than the IHSB Protection of Groundwater SRGs. The
remaining metals were detected in each of the collected sediment samples at concentrations less than either of the IHSB
SRGs.
No pesticides or PCBs were detected in any of the composite samples.
11. Estimated depth(s) of sediment in the area of the historic /current impounded area,
estimated amount of sediment in this area, and volume of this sediment proposed to be
removed. The depth of sediment varies from 1 foot in the upper reaches of the former lake
bed to as much as 30' against the concrete dam. Based on a profile of the river channel from
the base of the dam to the river bed above the elevation of the dam's crest, there may be
50,000 or more cubic yards of accumulated sediment. Our plan shows the removal of
approximately 40,000 cubic yards, with the remainder of the sediment in areas that make up
the newly restored river channel.
12. There is a large source of sediment located behind the dam (north side) in the area of
the current /historic impoundment and along the river channel immediately above the
impoundment. Provide additional details of how release of this sediment will be
minimized. How are these areas to be stabilized, measures to be taken to prevent significant
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amounts of sediment from mobilizing (e.g., mechanically remove sediment before dam removal,
use of sediment curtains, etc.), anticipated amounts of sediment that will be transported by
the stream and deposited downstream, sediment management practices to be utilized, including
those to mimic natural sediment transport, etc. The information provided should be
sufficient so that the Corps can determine (1) if a permit is required for this release of
sediment and (2) effects on the aquatic ecosystem. We have designed this project so that
little or no sediment is intended to be released during the removal of sediment and /or
restoration of the river channel, thru a variety of measures and by careful project
planning. By using a diversion berm and piping, we are planning to route the entire river
flow thru the active work area during construction. If rainfall or runoff exceeds the
diversion piping capacity, work will be halted until the river is once again contained. The
dam will remain in place during the majority of sediment removal, providing another means to
capture and settle any sediment -laden runoff. Extensive erosion control measures will be in
place to prevent sedimentation during construction of the access road, staging area, and
disposal area. The river channel restoration will be performed "in the dry" and properly
stabilized prior to allowing water to again be directed thru the channel. No material from
the demolition of the concrete dam will be deposited in the river, and a variety of woody
debris will be removed from the channel immediately below the dam. All woody vegetation that
is growing within the accumulated sediment in the former lake bed will be logged and removed
from the area, and all other vegetation will be mulched for ground cover.
Removal of the dam will generally cause sediment behind the dam to erode rapidly usually in a
discrete single event or in a series of discrete events which move sediment
downstream. There is a high variability in the amount of sediment and water carried by
streams over an annual cycle. Such high flows may occur as result of storm and seasonal
runoff events. Larger amounts of sediment may be considered de minimis in relationship to
such factors as location of the dam, the normal amount of erosion in the watershed, and bed
load that the stream carries during normal events.
When evaluating more than de minimis sediment flow, the Corps needs to consider factors like
the time of the year in which the dam removal activities will take place, normal seasonality
of high volume flows, intended /anticipated release volume, the speed of the drawdown, normal
amount of sediment in the watershed, and the potential for environmental harm (e.g.,
downstream species, stressors, stream bank stability, etc.).
Regulatory Guidance Letter (RGL) 05 -04 provides guidance on the discharge of sediments from
or through a dam and the breaching of dams, for purposes of Section 404 of the Clean Water
Act and Section 10 of the Rivers and Harbors Act of 1899. According to RGL 05 -04,
"Activities that are not usually considered regulated discharges of dredged material and do
not require Department of Army (DA) permits include actions such as ... breaching or removal of
a dam that results in the movement of only de minimus amounts of material... releases during
times of high water or flood stages for purposes of passing flood waters through the dam..."
As discussed and communicated with representatives of McGill Associates in the Fall of 2012,
in addition to the other fill activities on the site (i.e., culverts for roads, stream
restoration, etc.), the Corps must determine if DA authorization is also required for the
release of sediments from behind the dam. As stated above, please provide additional
information so that the Corps can determine if (1) the amount of sediment released is or is
not more than de minimus and (2) potential adverse effects of the sediments to the downstream
aquatic ecosystem. We would be happy to meet with you and bring our environmental /stream
restoration staff to discuss the sediment transport issue further. Again, it is our intent
thru design, permitting, scheduling, and construction observation to limit any sediment loss
during the project.
After reviewing the information you provide, the Corps may determine additional DA
authorization is required, such as the use of additional NWPs or an Individual Permit. Do
4

note the Corps may condition any authorization to require further activities to minimize the
potential adverse affects on downstream aquatic environments from the release of sediments.
Also, based upon the potential of sediment impacts to habitat downstream and water quality,
the Corps will coordinate with USFWS and NC Department of Natural Resources - Division of
Water Resources (DWR) to provide comments on the potential impacts to downstream species,
habitat, and water quality.
Once the Corps receives the information listed above and comments from USFWS and DWR, we will
be able to continue to process your application. If you have any questions please contact
me.
Sincerely,
David Brown, PG
Regulatory Specialist /Geologist
828 - 271 -7980, ext. 232
david.w.brown @usace.army.mil
USACE Wilmington District - Asheville Regulatory Field Office
151 Patton Avenue, Room 208
Asheville, NC 28801 -5006
9