20181064 Ver 1_More Info Recieved_20181005

October 1, 2018
Andy/Stephanie,
Please see.our comments to address the additional information request and to facilitate,
permitting of the proposed water'quality project. Let us know if you have any.
questions. Thank you.
The. Pre -construction notification (PCN) for the proposed Novozymes Treatment
Systems (SAW -2015-02074), received on August 2, 2018 is.incomplete.
The Nationwide Permit (NWP) condition 23 (a) and (b) states: The district engineer will
consider the following factors when determining appropriate and practicable mitigation
necessary to ensure that the individual and cumulative adverse environmental effects
are no more than minimal: (a), The' activity must be designed'arid constructed, to avoid
and minimize adverse effects, both temporary and. permanent; to waters of the United
States to the maximum extent practicable at the project site (i.e., on site)., (b) Mitigation
in all its forms (avoiding,, minimizing, rectifying, reducing, or compensating for.resource
losses) will be required to the extent necessary to ensure that the individual and
cumulative adverse environmental effects are no more than minimal.
In order for use to continue evaluating the proposed project, please provide the
following information:
1. Please indicate if the proposed impacts are permanent or temporary.
Response:
The intent of the proposed water quality improvement project is to address historic,
groundwater nitrate nitrogen entering surface waters on Novozymes property in two
watersheds and.two distinct unnamed tributaries (UT).' The groundwater entering these
waters reveals nitrate nitrogen concentrations >10.0 mg/L, exceeding NCAC 15A 2L
.0200 standards as well as stream standard violations per DEQ rule. Although the two
UTs with surface water exceedances originate on Novozymes property and are
addressed collectively in the approved Corrective Action Plan per DEQ,.they are not
interdependent of each other for function or through construction, maintenance, and
monitoring.
The proposed structures placed in the stream to impound water serve' several functions,
one to provide a means to capture, treat, and discharge water that enters the structure
,with >10b mg/L nitrate nitrogen, as Well as serving to improve adjacent wetlands and
:riparian buffers now degraded, or devoid from past watershed influences including.
.-pond..const.ruction,.diminishing abutting riparian wetlands,'and increased peak
discharges from agricultural fields.

Stream SA - Historic Pond 4 - Watershed 1 - Farm 2 occurs below two small tributaries
to Buffalo Creek, a WS IV class stream with a surface water nitrate nitrogen standard of
10.0 mg/L. An historic pond that was breached from a storm in 1998 resulted in
increased sediment deposition in the stream and riparian wetland loss over time. The
riparian buffer has not been reestablished due to the dynamic state of the stream and
abutting historic pond bottom trying to reach equilibrium. Installing the proposed
stream structure at a lower elevation than the dam would effectively create a grade
control in the stream, halting some sediment transport, and reestablishing a floodplain
bench, riparian wetlands, and restoring riparian buffer vegetation. For these reasons,
we propose to at least keep the structure in place for the period needed to attenuate
the nitrate nitrogen entering surface waters. At that time, the structure may be
replaced with a natural channel design grade control such as a rock cross vein, or
removed and allowed to equilibrate with the existing grade control as installed at the
outlet of the treatment structure depending on accumulated sediment at that time and
at the discretion of USACE/DEQ (See Cross Vein Cross Section - Figure A) .
Stream SE - Watershed 2 - Farm 1: Historic Sediment accumulations of >4 ft have
occurred in Watershed 2 - Farm 1 resulting in a severely incised stream channel and
greatly increased sediment transport during rainfall events. Adjacent agriculture fields
continue to shed water quickly with increased peak discharges during rainfall events in
this tributary. This UT also discharges directly to Buffalo Creek, a WS IV class
stream with a surface water nitrate nitrogen standard of 10.0 mg/L. Installing the
proposed stream structure would effectively create a grade control in the stream,
halting some sediment transport, and reestablishing a floodplain bench and riparian
wetlands. During construction the riparian buffer vegetation would be enhanced
through additional understory plantings. For these reasons, we propose to at least keep
the structure in place for the period needed to attenuate the nitrate nitrogen entering
surface waters. At that time, the structure may be replaced with a natural channel
design grade control such as a rock cross vein, or removed and allowed to equilibrate
with the existing grade control as installed at the outlet of the treatment structure
depending on accumulated sediment at that time and at the discretion of USACE/DEQ
(See Cross Vein Cross Section - Figure A) .
2. Please consider and discuss methods/treatment systems that can be placed in upland
areas that will avoid/minimize impacts to jurisdictional waters. If upland treatment can
be accomplished, please let us know. If not, please provide a detailed discussion of
factors that would preclude the use of an upland treatment system. Based on current
guidance from the Environmental Protection Agency (Region 4), the Clean Water Act
prohibits the designated use of jurisdictional waters from being used as pollution
treatment systems except in the most extreme situations.

Response:
During the pilot study phase of the surface water treatment project and as currently
permitted by USACE/DEQ, several treatment options and treatment media were
considered for nitrate nitrogen_removal. The selection of areas for treatment resulted
from extensive monthly water quality monitoring data that revealed strategic areas for
effective, optimal treatment. The location of the proposed inline structures are such
that treatment is maximized an'd adjacent impacts to buffers and wetlands are
minimized or avoided entirely. ,Offline options were considered for pumping Water from
each UT, treating, and discharging back to the stream; however, any offline option would
require'impounding water due to the base flow discharges for each OT. similar to any
inline treatment option. Ave`rag'e'flows in Watershed 2 -,.Farm 1 are 2 gpm and flows in
Watershed 1 - Farm 2 are 101gpm. Both UTs are shallow;;sand-bed type streams with
impacted dimension, pattern, and profile from historic and, ongoing 'sediment deposition
and transport, thus making it irr''possible to collect and treat'the water offline without
an impounding structure in the'stream and intake/pump;to deliver water to treatment
systems.
Therefore, in order to minimize impacts to riparian areas,to host the treatment systems,
manage discharges through riparian areas, costs to install additional pump/conveyance
infrastructure, power for pump's, and maintenance of inlets and discharge areas
following storm events, the inline treatment is preferred: The inline treatment also
allows for enhanced stream an8. riparian function as described previously in the short
and potentially long-term for th'e. watershed.
It should be noted stormwater would be diverted and allowed to flow downstream,
bypassing any treatment mechanism. Treatment of water is designed for the base -flow
condition and resulting'groundwater influences on the stream flow.
3. Based on the description in the PCN, 100 linear feet of channel on Stream S1 (SE) and
136 linear feet of channel on Stream S2 (SA) will be inundated. The Wilmington District
Regional Condition 3.2 (Mitigation for Loss of Stream Bed) states that for any NWP that
results in a loss of more than 150 linear feet of stream, the permittee shall provide a
mitigation proposal to compensate for more than minimal' individual and cumulative
adverse impacts to the aquatic environment. Based on the current information, a
compensatory mitigation proposa'I should accompany the PCN. Please provide a
'mitigation proposal and/or any additional information that.you believe would be helpful
regarding -the need for compensatory mitigation.
'';!,!.,Response:
I Although the two UTs with surface water exceedances originate on Novozymes property
and are addressed collectively in the approved Corrective. Action Plan per DEQ, they are
not interdependent of each other for, function or through construction.' The inline
treatment also allows for enhanced stream and riparian function as described previously

in the short and potentially long-term for the watershed. Along Stream S2 (SA),
approximately 5,000 ft2 of riparian buffer will be restored as well as approximately
3,000-6,000 ft2 of riparian wetlands consistently inundated by impounded
water. Additional riparian areas within and outside the 50 ft buffer of each UT (S1 (SE)
and S2 (SA)) will be enhanced with understory and overstory plantings. For the historic
Pond 4 (Watershed 1- Farm 2), stream S2 (SA), a bankfull bench will be established
allowing water to access a flood plain, thus restoring a component of the stream absent
with the current hydrogeomorphology and from past impacts due to sedimentation and
pond dam construction.
Therefore, we propose no additional mitigation is necessary for the proposed project
due to the improved water quality benefits and functions of the project including
surface water treatment, long-term stream stability, wetland creation and
enhancement, and riparian buffer restoration and enhancement from construction
activities.
4. If after considering #2 and #3 above, you still plan to apply for these impacts, please
provide a plan view drawing that superimposes the collection boxes superimposed on
the stream segments. The drawings should distinguish the collection boxes from the
remainder of the stream segment that will also be inundated by the proposed project.
Response:
Please see Figures F2-1, F2-2, F2-3 and Figures F1-1, F1-2 showing the location of the
collection boxes superimposed on the stream segments proposed for water quality
improvement.
5. In Section 4g, the applicant states, "Water exiting the system will be controlled using
natural channel design structure to protect the stream and structure during peak flow
events". Please indicate if any additional stream segment below the proposed collection
boxes will be impacted to complete the natural channel design. If so, please provide
impact amounts and the appropriate plans/drawings.
Response:
Please see Figure A showing a typical cross vane for grade control and scour hole
creation. The cross vane is proposed within the footprint of the old dam, thus
improving and stabilizing this reach from further degradation, dam wall sloughing, and
downstream migration of sediment. Bankfull benches will be established as well as a
natural rock cross vane grade control, thus eliminating impacts in this reach, and
restoring stream function. The rock vane structure will be located at the outlet of the
treatment box, occupying approximately < 41f of stream channel. Below -grade footer
rocks will be placed at the outlet to protect the rock vane structure from migration as
well as foster rocks anchored to the banks. Water will be allowed to enter the stream
from the treatment structure and rock vane outlet with no additional bed material in
the scour hole.

6. Please confirm if the location of the proposed collection boxes are in the same
locations as previously permitted or if they are located -at different points on those
stream channels.
Response:
The proposed collection box for S2 (SA) Farm 2 Historic Pond 4 is located in a similar
.,location as permitted under NWP18..The proposed collection box for S1 (SE) Farm.1 is
located in a new, location downstream of the pilot study impoundment (Figures F1-1, Fl -
The original structure placed under NWP18 in this UT remains in place in the event
additional treatment is required at the origin of the UT relating to documented nitrate
nitrogen inputs into the stream from groundwater. Upon completion of the required
Corrective.Action'Plan and attenuation of nitrate nitrogen, this structure will be ,
removed and at the discretion of USACE/DWQ.
Included and attached are updated location maps for'Streams S1 (SE), Farm 1 and 'S2 (SA)
Farm 2 (Figures F2-1 and F1-1).
Let me know if you have any questions. Thanks.
=Scott

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0 Storm Bypass Elev. 311.25'+/-
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— — — 100'— — — Existing Grade - 5' contours
Finished Grade P contours
— — 100'— — Finished Grade 5' contours
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rACross Vane Structure
Preliminary
Drawing
Not For
Construction Use
Novozymes North America, Inc.
Details - Pond 4 Construction
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1119 Purfoy Road 7
Fuquay Vwina, NC 27526
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----- 102'----- Existing Grade -1' contours
— — — 100'— — — Existing Grade - 5' contours
Finished Grade 1' contours
— — 100'— — Finished Grade 5' contours
Preliminary
Drawing
Not For
Construction Use
Novozymes North America, Inc.
Constructed Wetland Project - Pond 4
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1119 Purroy Road
Fuquay Va<iuq NC 27526
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Figure i-1-1 -
GRAPHIC SCALE
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( IN FEET )
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Proposed Cross Vane Structure
Aerial Image from Google Earth
May 2018 Image
Lat: 36° 06'21.50" N
Lon: 78° 24'29.74" W
Approx. Head of Drainage Channel
Preliminary
Drawing
Not For
Construction Use
Novozymes North America, Inc.
Treatment Structure Locations - Farm 1
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1119 Purfoy Road
FuquayVarine, NC 27526
Telephone: [phone]

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Collection Inlet
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Collection Inle[
Outlet Pipe = Collection Inlet
Outlet Pipe '
4.0'
Farm 1
Control Elevations
Storm Bypass Elev. 300'+/ -
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Elev. 299.33' Existing Channel
Elev. 299'
"
Keyway Cut
Elev. 296'
1
Key ----102'----- Existing Grade - 1' contours
— — 100'– — – Existing Grade - T contours
— — — — — — Top of Channel
— — — — — — Centerline - Chamtel
Collection Structure
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riCross Vane Structure
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Preliminary
Drawing
Not For
Construction Use
Novozymes North America, Inc.
Details - Farm 1 Structure Construction
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1119 Purfoy Road
Fuquay Varina, NC 27526
Tclephone:[phone]
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FigurE7
Typical Cross Vane Construction Details
Bankfull
Stage
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Section A -A'
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Stage
Flow I I
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Plan View
Section B -B'
Construction Notes:
1, Rocks placed in the Cross vane should be placed with no gaps.
2. Rock diameter should be as large as poosible, with a typical diameter of no less than 2'.
3. Cross Vane placement should act to keep thalweg as nearly as possible to the center of channel.
4. Bankfull bench should be protected and re -vegetated after construction
Preliminary
Drawing
Not For
Construction Use
Novozymes North America, Inc.
Stream Flow Control - Construction Details
Cn lord Cli�eaiq and Ccoslilfiog,
1119 Purfoy Road
Fwuay Varma, NC 27526
Telephone:[phone]
www.cmwfurden¢ineerin¢._ N2NA_St.dwg