20111013 Ver 1_More Info Received_20121018

11- koi3
Martin Marietta Materials
P.O. Box 30013
Raleigh, North Carolina 27622 -0013
Telephone [phone]
Facsimile (919) 510 -4739
E -Mail: steve.whitt @martinmarietta.com
Steven S. Whitt
Director, Environmental Services
October 16, 2012
Mr. Gil Vinzani, P.E.
NC Division of Water Quality
Complex NPDES Permits Unit
1617 Mail Service Center
Raleigh, NC 27699 -1617
Subject: Request for Additional Information — NCO089168
Amended Technical Memorandum
NPDES Application
Martin Marietta Materials Inc. — Vanceboro Quarry
Dear Mr. Vinzani:
OCT 1 8 2012 D
As discussed with you previously, based on a September 21, 2012 meeting held in the NCDENR
Washington Regional office with staff from the NC Division of Marine Fisheries and NC
Wildlife Resource Commission, changes have been made to the original Technical Memorandum
(dated Sept. 6, 2012) prepared by Kimley -Horn and Associates, Inc. The changes help to clarify
comments received by reviewing agencies. The flood and stability analysis is now contained in
one report and the water quality analysis is in another. Additional information and figures have
been added to each.
Two copies are included for your review.
A copy has also been mailed to the following recipients:
• Mr. Paul Rawls, NCDENR Fayetteville Regional Office
• Mr. Ian McMill an, NCDENR Wetlands and Stormwater Branch (Central Office)
• Mr. Roger Thorpe, NCDENR Washington Regional Office
• Ms. Maria Dunn, NC Wildlife Resources Commission (WRO)
• Mr. Kevin Hart, NC Division of Marine Fisheries (WRO)
Please get in touch with this office if any additional information is needed on this matter.
Sincerel ,
Steve Whitt, P.E.
Director, Environmental Services

Date: October 10, 2012
Project: Vanceboro Site
Martin Marietta Materials
Craven and Beaufort Counties, North Carolina
Subject: Water Quality Analysis
Purpose
The following Technical Memorandum is prepared to summarize the results of analyses performed to address
the North Carolina Division of Water Quality ( NCDWQ) and United States Army Corps of Engineers
(USACE) comments regarding water quality, in particular pH and salinity, associated with the proposed
addition of the quarry dewatering discharge to Blounts Creek from the proposed Vanceboro Site. This memo
also will provide Coastal Zone Resources (CZR) with predicted zones of potential impacts so the company
can further analyze the potential impacts to essential aquatic habitats for fish, benthic invertebrates, and
vegetation.
This Technical Memorandum was originally submitted to NCDWQ as a combined report titled "Stability,
Flood, and Water Quality Analyses ", dated September 6, 2012. This amended memorandum has been
prepared to clarify comments received by reviewing agencies that combining the flood and stability analysis
with the water quality analysis created some confusion. Included herein is the water quality (pH and salinity)
analysis only, as well as an addendum with additional information in response to comments provided by the
NC Division of Marine Fisheries (NCDMF) and NC Wildlife Resource Commission (NCWRC) at a
September 21, 2012 meeting held in the NCDENR Washington Regional Office.
Background
The estimated maximum discharge rate from quarry dewatering is approximately 18 cfs (approximately 12
mgd). As part of the application and review process for the Individual 404 Permit, the associated Water
Quality Certification, and the NPDES Discharge Permit, regulatory agencies raised several concerns related to
stream stability, flooding, and water quality.
The dewatering discharge primarily consists of groundwater infiltration from the Castle Hayne aquifer.
Groundwater Management Associates (GMA) provided water chemistry analysis from wells placed in the
aquifer at the Vanceboro site that were used to perform the pump test /water quality analysis. Kimley -Horn
and Associates, Inc. (KHA) gathered additional existing conditions data to pH and salinity throughout the
C FJ Kimley -Horn 1 of 15
and Associates, Inc,

Blounts Creek system as well. To assess the data, KHA used spreadsheet models. The data collection and
analytical methods are discussed in detail in the attached documents and summarized below.
■ Water Quality—The two main water quality parameters that the quarry dewatering discharge could
affect are pH and salinity. The pH of the existing headwater /swamp streams is very low (4.0 to 5.5). The
results of the analysis predict that the pH of these systems would be elevated to 6.5 to 6.9. Such a change
would not necessarily be considered a negative change as more numbers and diversity of intolerant species
need higher pHs to survive. The effect of the pH would likely be noticeable from the discharge point to
the confluence with Herrings Run where the ambient pH level is near 6.
Salinity also is a concern for estuarine species of flora and fauna. The beginning of the estuary has been
established at the confluence of Herrings Run and Blounts Creek. A volumetric displacement model was
developed to estimate the salinity change that would result from the addition of the dewatering discharge.
The model predicts no dramatic change in salinity and such changes may be masked by natural variability of
the systems from tides and runoff events. It is unlikely that mobile species (such as fish and swimming
invertebrates) would be affected by such a change; however, aquatic vegetation —like salt marsh grasses —may
be affected because such species can be out - competed by freshwater species.
Conclusions
Water Quality—The results of the pH analysis suggest that CZR focus on evaluating the effects of raising
the pH from 4.0 -5.5 up to 6.5 to 6.9 above the confluence of Herrings Run. It is not anticipated that
predicted changes to salinity would be enough to affect mobile aquatic species. CZR would likely need to
provide a narrative assessment of what kinds of changes could occur (if any). The zone of impact for
immobile plants and invertebrates may be larger and should be assessed by CZR from Herrings Run
down to the Cotton Patch Subdivision. Changes may not be enough to require more than a narrative
discussion of potential changes.
Cmley Ki
-Horn 2 of 15
M/1 and Associates, Inc.

0
Table of Contents
1.0 Salinity Evaluation .......................................................... ............................... 4
1.1
Background .............................................................................. ..............................4
1.2
Methods ................................................................................... ..............................4
Figure 1 -1: Salinity Sampling Points Map ............................................................. ...............................
6
1.3
Results and Discussion ............................................................ ...............................
7
Table 1 -1: Measured Salinity ofBlounts Creek ........................................................ ..............................7
Table 1 -2: Measured vs. Predicted Salinity ofBlounts Creek Downstream of Herrings Run ......................9
Figure 1 -2: Measured and Predicted Salinity ofBlounts Creek ................................. .............................10
2.0 pH Evaluation .............................................................. ...............................
11
2.1
Background ............................................................................. .............................11
2.2
Methods .................................................................................. .............................11
Table 2 -1: pH of Blounts Creek at Various Quarry Discharge to Stream Water Ratios ...........................11
Figure 2 -1: Relationship of pH to Percent Quarry Water on Receiving Streams ...... .............................12
2.3
Results and Discussion ............................................................ .............................12
References.............................................................................
...............................
13
Addendum.............................................................................
...............................
14
Attached: Salinity Tables
GMA Aquifer Water Chemistry Sample Report
��mley -Horn
Ki and Associates, Inc.
3of15

r
1.0 Salinity Evaluation
1.1 Background
The NCDWQ requested that Martin Marietta Materials evaluate the effect on salinity in Blounts
Creek from the potential maximum quarry dewatering discharge from the proposed quarry near
Vanceboro, NC, starting at the point where NCDWQ considers estuarine (i.e., salt) waters begin at
the confluence of Blounts Creek with Herrings Run. Per discussions with NCDWQ, it was agreed
that a simple mass balance or other appropriate analysis would be suitable for an initial study on the
potential impact that the discharge may have on salinity. KHA looked at several ways to approach
such an evaluation and concluded that a simple model that evaluates the potential volumetric
displacement of more saline water by the less saline quarry discharge may be adequate to
conservatively estimate the potential effect of the proposed discharge on the salinity of the creek.
1.2 Methods
KHA determined that it would be necessary to collect field data to define salinity profiles along
Blounts Creek starting at the confluence of Blounts Creek with Herrings Run and ending
approximately one mile downstream of the Cotton Patch Subdivision. A number of parameters were
measured including conductivity, which was converted to salinity. These measurements were taken
using a YSI 6920 water quality "sonde" meter. Stream velocity was measured at several observation
locations to estimate channel discharge.
Sampling was performed on three separate days: April 4`h, 2012; April 13`h, 2012; and May 315`,
2012. Sampling dates were chosen to give a variety of flow and salinity conditions. Sampling on April
4`h occurred 3 days after approximately 0.5 -1.0 inches of rain occurred in the watershed. Sampling on
April 13`h occurred after several dry days, with the most recent rainfall occurring a week earlier on
April 6 -7`h (about 0.2 -0.3 inches of rain). Sampling on May 3151 occurred a day after tropical storm
Beryl dropped approximately 3.5 inches of rain on the watershed. These sampling events represent a
moderate flow, low /base flow, and high flow conditions in Blounts Creek, respectively. The sampling
event on April 4`h included only two readings at the Cotton Patch Subdivision and at the confluence
with Herrings Run. Sampling on April 13`h and May 13`h included measurements starting at the
water surface and continuing at 2 -foot intervals down to a depth of 10 feet on Blounts Creek from
the confluence with Herrings Run to Blounts Bay at intervals of approximately 1,000 feet.
Locations of sampling observations points can be seen in Figure 1 -1. A salinity profile with isohaline
lines of the April 13`h samples were developed using CADD. The resulting map is represented by the
isohaline contours labeled "salinity measured 4/13/2012" in Figure_ 1 -2: Measured and Predicted
Salinity of Blounts Creek. The profile data was then used to generate predicted isohaline lines
(labeled "predicted salinity") that could result from the addition of a maximum of 18 cfs of quarry
dewatering discharge.
CKimsey -Horn 4 of 15
�/1 and Associates, Ina

To produce the predicted isohaline contours, a number of assumptions were made:
■ Stream discharge (with or without the addition of the dewatering discharge) does not completely
mix with the more saline estuarine waters.
■ Quarry water discharge was "instantaneously" added to the stream discharge meaning that the
fresh water would simply overrun the more saline water (as it currently does).
These assumptions are shown by the actual measurements taken and illustrated in Figure 1 -2. Due to
this assumption, the addition of the quarry dewatering discharge can be seen more as a volumetric
displacement with some mixing as already occurs naturally. We will be able to further establish this
concept by resampling after a rain event, which would increase the stream (freshwater) discharge in a
similar manner to the addition of the quarry dewatering discharge. Using a "volume displacement
model' provides a way to avoid having to assess the effect of tides and other events. The model only
represents a snapshot in time.
A simple explanation of the model is that the volume displacement is taken as the ratio of the
maximum quarry dewatering discharge to the stream discharge at any given point along the stream.
The ratio of quarry dewatering discharge to the stream discharge would decrease as one progresses
downstream. The model assumes that the stream discharge is proportional to the drainage area and
the stream cross section at any given point along the stream. The presence of the saline water is based
on the fact that it is denser than fresh water resulting in a horizontal stratification such that the
freshwater overruns the more saline water as evidenced by the actual data. This tendency also can be
modeled using the energy equation that takes into account the density of water as well as air pressure.
If air pressure is assumed to be constant over the entire system, this allows the less dense water to
"float" over the denser water. This fact further supports the assumption that the water will continue
to remain stratified by salinity. Assuming a volumetric displacement as a percent increase of the
quarry dewatering discharge versus the stream discharge at any given point is a sensible and
conservative assumption. To determine the volumetric displacement, the ratio of discharge -based
volume displacement was used to interpolate a displaced value of the salinity between every point
measured.
Can Wmley -Horn 5 of 15
and Associates, Inc.

' 3 { 1150 �_ 3
1400 r•
2000
1.1
000
00 400
1 inch = 2,000 feet s

1.3 Results and Discussion
The flow conditions on Blounts Creek were taken during what can be characterized as two base -flow
conditions (4/13/2012 base -low, and 4/4/2012 base - moderate) and one post -storm condition
(5/31/2012 high -flow). Each flow condition has an effect on the salinity of Blounts Creek. Table 1 -1
shows salinity of Blounts Creek at two locations.
Table 1 -1: Measured Salinity of Blounts Creek
' Salinity units are PSU (Undiluted sea water = 35 PSU)
Z Sampling conducted after a week of no rain. Approximate estimated flow rate = 25 cfi at Herrings Run and 100 cfi at the
Cotton Patch Subdivision
s Sampling conducted one day after -0.5 inch rain. Approximate calculated flow rate = 50 cfs at Herrings Run and 200 cfi
at the Cotton Patch Subdivision
4 Sampling conducted one day after -3.5 inch rain. Approximate calculated flow rate = 800 cfi at Herrings Run and 1,700
cfs at the Cotton Patch Subdivision.
Note: Flow rates calculated from cross - sectional area and velocity readings at sampling points. Base -Low flow was estimated
because velocity readings were too low to record.
Although the samples represent only an instant in time, conclusions can be drawn that illustrate the
salinity dynamics of Blounts Creek and the correlation of salinity and flow:
■ Salinity increases with depth.
■ Salinity increases downstream as the creek approaches Blounts Bay.
■ As flow increases, salinity decreases.
Based on sampling conducted on the 4`h and 13`'' of April, 2012 it can be concluded that salinity in
Blounts Creek will be higher after a dry period. This increase in salinity has an upper limit dictated
by the salinity of the Pamlico River at Blounts Bay. Sampling conducted on May 31", 2012 after
Tropical Storm Beryl shows that a moderate intensity storm (3.5 inches of rain for a 24 -hour
duration storm represents a 1- to 2 -year occurrence interval) has the ability to completely push
salinity out of Blounts Creek. These fluctuations of salinity appear to be a natural dynamic of Blounts
MPIIdmiey -Horn 7 of 15
and Associates, Inc.
Measured Salinity'
Sample Location
Depth
Base -Low Flow'
Base-Moderate
High -Flow 4
Flow
(4/13/2012)
(4/4/2012)
(5/31/2012)
Immediately downstream of
3
1.08
0.07
0.03
the confluence with Herrings
Run
8
3.03
--
0.03
In front of the Cotton Patch
3
3.11
2.03
0.05
launch area
8
5.65
4.40
0.05
' Salinity units are PSU (Undiluted sea water = 35 PSU)
Z Sampling conducted after a week of no rain. Approximate estimated flow rate = 25 cfi at Herrings Run and 100 cfi at the
Cotton Patch Subdivision
s Sampling conducted one day after -0.5 inch rain. Approximate calculated flow rate = 50 cfs at Herrings Run and 200 cfi
at the Cotton Patch Subdivision
4 Sampling conducted one day after -3.5 inch rain. Approximate calculated flow rate = 800 cfi at Herrings Run and 1,700
cfs at the Cotton Patch Subdivision.
Note: Flow rates calculated from cross - sectional area and velocity readings at sampling points. Base -Low flow was estimated
because velocity readings were too low to record.
Although the samples represent only an instant in time, conclusions can be drawn that illustrate the
salinity dynamics of Blounts Creek and the correlation of salinity and flow:
■ Salinity increases with depth.
■ Salinity increases downstream as the creek approaches Blounts Bay.
■ As flow increases, salinity decreases.
Based on sampling conducted on the 4`h and 13`'' of April, 2012 it can be concluded that salinity in
Blounts Creek will be higher after a dry period. This increase in salinity has an upper limit dictated
by the salinity of the Pamlico River at Blounts Bay. Sampling conducted on May 31", 2012 after
Tropical Storm Beryl shows that a moderate intensity storm (3.5 inches of rain for a 24 -hour
duration storm represents a 1- to 2 -year occurrence interval) has the ability to completely push
salinity out of Blounts Creek. These fluctuations of salinity appear to be a natural dynamic of Blounts
MPIIdmiey -Horn 7 of 15
and Associates, Inc.

Creek between Herrings Run and the Cotton Patch Subdivision. The maximum proposed quarry
discharge of 18 cfs (12 million gallons per day) would be only 1 -2% of the flow rate measured after
Tropical Storm Beryl. As such, the effects of the quarry discharge likely would not be noticeable
during these kinds of flow conditions and should not have the same effect on the salinity profile as a
moderate intensity storm such as Tropical Storm Beryl. Accordingly, it appears more likely that
effects from the quarry discharge only would be noticeable at discharges closer to base -flow
conditions.
The volume displacement model was developed as a tool to predict the effects on salinity from an
increase of 18 cfs (approximately 12 mgd) on salinity in Blounts Creek due to the proposed quarry
dewatering discharge at base -flow conditions. Table 1 -2 and Figure 1 -2 show how the model predicts
that the isohaline lines would be deeper and further downstream when comparing the natural- stream
discharge plus quarry discharge versus the actual, measured conditions —i.e., the natural- stream
discharge alone. The model shows that additional flow essentially "pushes" salinity downstream, but
to a much smaller degree than discharge from a 3.5 -inch rainfall would, for instance.
In this scenario, comparing the salinity measurements taken during the two base -flow discharges (low
and moderate) demonstrate how the addition of the quarry discharge could affect the system. The
difference between the discharges from the low -base flow and moderate base flow at Herrings Run
would be very similar to the discharge difference between the low -base flow and the low -base flow
with the quarry discharge added to it. The difference between the discharges of the low -base flow and
moderate -base flow at the Cotton Patch Subdivision are much larger than the difference between the
low -base flow and low -base flow plus quarry discharge would be. The volume displacement model
over- estimated the predicted salinity (0.07 measured versus 0.7 predicted) at the Herrings Run
confluence. The model also underestimated the predicted versus measured salinity at 3 feet (2.0
measured versus 1.6 predicted) and 8 feet (4.4 measured versus 2.8 predicted) at the Cotton Patch
Subdivision. In any event, the volume displacement model does appear to provide an indication of
the relative predicted changes to salinity from the addition of the quarry discharge that can be
expected during low to moderate base flow conditions.
Kimley -Horn 8 of 15
C M and Associates, Ina

Table 1 -2: Measured vs. Predicted Salinity of Blounts Creek Downstream of Herrings Run
Distance
Downstream
of Herrings
Run (ft)
Depth
Below
Surface
(ft)
Measured
Salinity'
(411312012)
Predicted
Salinity'
Distance
Downstream
of Herrings
Run (ft)
Depth
Below
Surface
(ft)
Measured
Salinity'
(411312012)
Predicted
Salinity'
200
0
0.88
0.51
6,000
0
2.04
1.51
200
2
1.08
0.96
6,000
2
2.14
2.07
200
4
1.70
1.34
6,000
4
2.55
2.25
200
6
2.72
2.13
6,000
6
3.41
2.78
200
8
3.03
2.85
6,000
8
4.51
3.69
200
10
3.12
3.07
6,000
10
5.33
4.72
1,000
0
1.29
0.75
8,000
0
2.22
1.64
1,000
2
1.33
1.31
8,000
2
2.27
2.23
1,000
4
1.77
1.52
8,000
4
2.49
2.33
1,000
6
2.87
2.23
8,000
6
3.98
2.88
1,000
8
3.46
3.12
8,000
8
4.92
4.22
1,000
9.6
3.56
3.50
8,000
10
5.39
5.05
2,000
0
1.61
0.94
10,000
0
2.47
2.10
2,000
2
1.67
1.64
10,000
2
2.51
2.48
2,000
4
2.02
1.82
10,000
4
3.41
2.65
2,000
6
2.65
2.28
10,000
6
4.27
3.54
2,000
8
3.74
3.11
10,000
8
5.00
4.38
2,000
10
4.02
3.86
10,000
9.1
5.48
5.08
3,000
0
1.87
1.38
12,000
0
2.64
2.25
3,000
2
1.96
1.89
12,000
2
3.01
2.70
3,000
4
2.07
1.99
12,000
4
3.23
3.04
3,000
6
2.36
2.15
12,000
6
4.05
3.35
3,000
8
3.96
2.78
12,000
8
5.76
4.31
3,000
10
4.51
4.10
12,000
10
6.07
5.80
4,000
0
1.76
1.30
13,000
0
2.84
2.42
4,000
2
1.89
1.80
13,000
2
3.11
2.88
4,000
4
2.20
1.97
13,000
4
3.47
3.16
4,000
6
3.33
2.49
13,000
6
5.01
370
4,000
8
4.13
3.54
13,000
8
5.65
5.11
4,000
10
4.64
4.27
13,000
10
6.10
5.72
5,000
0
1.92
1.42
14,000
0
3.24
2.75
5,000
2
1.97
1.93
14,000
2
3.28
3.24
5,000
4
2.44
2.09
14,000
4
3.49
3.31
5,000
6
3.30
2.67
14,000
6
4.87
3.69
5,000
8
4.20
3.53
14,000
8
6.36
5.09
5,000 1
10
4.73
4.34
14,000
9.3
6.45
6.38
' Salinity units are PSU (Undiluted sea water = 35 PSU)
Note: Highlighted cells are approximate location of the Cotton Patch Subdivision
C:Mn Wmley -Horn 9 of 15
and Associates, Inc.

0
H
LLJ
W
Lk-
2
F-
IZ
LLJ
0
—2
—4
—6
In
FIGURE 1-2: MEASURED AND PREDICTED SALINITY OF BLOUNTS CREEK
C=I1 Kimley -Horn
and Associates, Ina
X11-1
►r� ,
DISTANCE DOWNSTREAM OF CONFLUENCE WITH HERRINGS RUN (FEET)
12000
14000
SALINITY. MEASURED
(4/13/2 ?1�)
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
SALINITY, PREDICTED
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
COTTON PATCH
SUBDIVISION
10 of 15

2.0 pH Evaluation
2.1 Background
The proposed discharge from the Vanceboro quarry into Blounts Creek will mostly come from the
Castle Hayne aquifer. Based on data from aquifer testing conducted by Groundwater Management
Associates (GMA), discharge from the Castle Hayne aquifer near the Vanceboro Site had a pH of
6.94, an alkalinity of 321 mg /L, and a total hardness of 316 mg /L. Based on these numbers, it was
assumed that the hardness and alkalinity are primarily from calcium carbonate (CaCO3), which
would give this discharge a very strong buffering capacity. Additionally, the pH of the water in
Blounts Creek above the confluence with Herrings Run was measured between 4.0 and 5.5 by CZR
and KHA. Given the available water quality data, a simple water chemistry model was developed to
determine what the predicted pH of the Blounts Creek system might be with the introduction of the
quarry dewatering discharge.
2.2 Methods
It is assumed that the alkalinity of the quarry dewatering discharge is carbonate (CO3), bicarbonate
(HCO3), and carbonic acid (1-12CO3). Natural acidity in the stream is likely tannic acid and other
organic acids; however, for the sake of this study it was assumed that the pH is from hydrogen ions
only (H'). This assumption that there will be no buffering from organic acids is conservative because
the organic acids likely would provide some buffering at the lower pH. A spreadsheet model was
developed to assess the proton condition and to assess various ratios or percentages of quarry water to
stream water. Since the pH of the quarry water was 6.94, it was assumed that bicarbonate (HCO3)
would be the dominant base form. Table 2 -1 shows the predicted pH of the stream as a volumetric
ratio of quarry discharge water to stream water.
Table 2 -1: pH of Blounts Creek at Various Quarry Discharge to Stream Water Ratios
% Quarry
Water
% Stream
Water
Ratio of Quarry to
Stream Water
H z CO s
HCO s
H
pH
10%
90%
1:9
1.54E -04
1.66E -04
4.65E -07
6.33
20%
80%
1:4
2.08E -04
4.33E -04
2.42E -07
6.62
30%
70%
3:7
2.63E -04
6,99E -04
1.89E -07
6.72
40%
60%
2:3
3.17E -04
9.66E -04
1.65E -07
6.78
50%
50%
1:1
3.72E -04
1.23E -03
1.51 E -07
6.82
60%
40%
3:2
4.26E -04
1.50E -03
1.43E -07
6.85
70%
30%
7:3
4.81 E -04
1.77E -03
1.37E -07
6.86
80%
20%
4:1
5.35E -04
2.03E -03
1.32E -07
6.88
90%
10%
9:1
5.89E -04
2.30E -03
1.29E -07
6.89
Receiving stream waters are assumed to have a pH of 4.0
CMn Kimley -Horn 11 of 15
and Associates, Inc.

7.0
6.5
6.0
X 5.5
5.0
4.5
40
Figure 2 -1: Relationship of pH to Percent Quarry Water on Receiving Streams
0% 100/0 20% 30'9 40'9 50'D 60% 70% 80% 90'/O 100%
Percent quarry Water
2.3 Results and Discussion
The model predicts that as the ratio of quarry water to stream water goes from 1:9 (10% quarry
water) to 9:1 (90% quarry water), the pH will begin to rise from 6.3 to 6.8. The pH at the Herrings
Run confluence was measured at approximately 6.5 on April 13`h, 2012. This means that the pH
below the confluence of Herrings Run and Blounts Creek will likely remain at current conditions;
however, the pH of Blounts Creek upstream of the confluence with Herrings Run is expected to
increase from a range of 4.0 -5.5 (as measured on April 13`h, 2012) to 6.3 -6.9 from the addition of the
quarry dewatering discharge.
C• Kimley -Horn 12 of 15
M� and Associates, Ina
'
Mloom
a
r1111111
0% 100/0 20% 30'9 40'9 50'D 60% 70% 80% 90'/O 100%
Percent quarry Water
2.3 Results and Discussion
The model predicts that as the ratio of quarry water to stream water goes from 1:9 (10% quarry
water) to 9:1 (90% quarry water), the pH will begin to rise from 6.3 to 6.8. The pH at the Herrings
Run confluence was measured at approximately 6.5 on April 13`h, 2012. This means that the pH
below the confluence of Herrings Run and Blounts Creek will likely remain at current conditions;
however, the pH of Blounts Creek upstream of the confluence with Herrings Run is expected to
increase from a range of 4.0 -5.5 (as measured on April 13`h, 2012) to 6.3 -6.9 from the addition of the
quarry dewatering discharge.
C• Kimley -Horn 12 of 15
M� and Associates, Ina

References
Chow, Ven Te (1959). Open- Channel Hydraulics. Caldwell, NJ: The Blackburn Press.
i
Fry, Brian (2002). Conservative Mixing of Stable Isotopes Across Estuarine Salinity Gradients: A Conceptual
Framework for Monitoring Watershed Influences on Downstream Fisheries Production. Estuaries and
Coasts, 25, 264 -271.
Stenstrom, Petter (2004). Hydraulics and mixing in the Hudson River estuary: A numerical model study of
tidal variations during neap tide conditions. journal of Geophysical Research, 109(C04019), 1 -12.
Snoeyink, Vernon L., & Jenkins, David (1980). Water Chemistry. New York, NY. John Wiley & Sons.
UNESCO (1981). Background Papers and Supporting Data on the Practical Salinity Scale 1978 (UNESCO
Technical Papers in Marine Science 37). Place de Fontenoy, Paris: United Nations Educational, Scientific
and Cultural Organization.
U.S. Geological Survey (1993). Low -Flow Characteristics of Streams in North Carolina (United States
Geological Survey Water - Supply Paper 2403). Denver, CO: US Government Printing Office.
C• � Kimley -Horn 13 of 15
= and Associates, Inc.

Addendum
Response to Comments Provided by NC Division of Marine Fisheries and NC Wildlife Resource
Commission on September 21, 2012
Date: October 10, 2012
Project: Vanceboro Site
Martin Marietta Materials
Craven and Beaufort Counties, North Carolina
Subject: Response to Comments by NC Division of Marine Fisheries and NC Wildlife Resource
Commission
Kimley -Horn and Associates, Inc. (KHA), Martin Marietta Materials (MMM), Coastal Zone Resources
(CZR) met with NC Division of Marine Fisheries (NCDMF) and NC Wildlife Resources Commission
(NCWRC) on September 21, 2012 held in the NCDENR Washington Regional Office to discuss their
comments on the KHA Technical Memorandum "Flooding, and Water Quality Analyses ", dated September 6,
2012. This addendum has been prepared to provide additional information /discussion in regard to the
general comments provided at the meeting.
■ Comment— The predictive model for the potential change of salinity indicates that, on average for a
given concentration, that salinity will be less at any given location below Herrings Run.
Kimley -Horn Response Extensive salinity stratification data was gathered on a day of normal
springtime base flow and another day of storm discharge conditions (one day after Tropical Storm
Beryl) in April 2012. Less extensive data was also gathered during a preliminary site visit where the
estimated flow was approximately twice the previous base flow observed during the extensive data
gathering. KHA noted that salinity was flushed from the system after Tropical Storm Beryl to well
below the Cotton Patch Subdivision. The other springtime base flow sampling events suggested that
the salt wedge appears to move downstream with an increase in flow. The estimated discharge
difference between the two normal springtime flow conditions is approximate to the proposed quarry
discharge. The results suggest that the salinity wedge appears to be similar, but may simply be
displaced downstream.
■ Comment — An increase in freshwater discharge could lead to oxygen depletion by increasing the
amount of stratification due to a larger wedge of freshwater over running the more saline water.
Strong salinity gradients were recording during recent fish kills along Blounts Creek.
Kinley -Horn Response —It is understood that a strong gradient could prevent the transfer of oxygen
to lower portions of the water column. It is our understanding that the fill kills referred to occurred
during droughts. Under drought conditions, the freshwater discharges are lower by volume, but move
Kimley -Horn 14 of 15
C and Associates, Inc.

more slowly resulting in less potential for turbulent mixing. Such advective conditions could prevent
turbulent mixing and oxygen transfer, allowing for the formation of a strong salinity gradient created
by fresh water overrunning. Turbulent mixing (as opposed to diffusion, for instance) is likely the
most prevalent means of transferring dissolved oxygen throughout the water column and weakening a
salinity gradient. The increased discharge from the quarry would actually increase the opportunity for
turbulent mixing by adding more kinetic energy to the system. This, in turn, would help transfer
more dissolved oxygen across the salinity gradient into the deeper water by mixing.
■ Comment— Increased erosion from the increase in quarry discharge may result in increased turbidly.
Kimley -Horn Response —The stability analysis conducted shows that even if the full 18 cubic feet
per second (cfs) of discharge were instantly distributed to Outfalls 1 and 2, the velocities and shear
stresses experienced throughout the streams would not be increased to the point that excessive erosion
would occur, thereby increasing turbidity downstream. Additionally, the anticipated discharge of 18
cfs would likely gradually increase over a period of years, further allowing any change in channel
geometry to reach equilibrium gradually without becoming unstable. Therefore, significant bank
failure and stream bed erosion that could cause a significant amount of turbidity or sedimentation is
not anticipated.
Comment— There is a concern that the quarry discharge would either contain nutrients or create
some mechanism, such as erosion, that would release nitrogen or phosphorus.
Kimley -Horn Response— The groundwater from the Castle -Rayne aquifer is not known to carry
excessive amounts of nitrogen. See the response above for a discussion of potential erosion.
Kimley -Horn 15 of 15
and Associates, Inc.

Attachment 1
Salinity Tables

Measured vs. Predicted Salinity
Distance Downstream of Confluence
with Herring Run (ft)
Depth below
Surface (ft)
Salinity measured
(4/13/2012)
Salinity Predicted
200
0
088
051
200
2
108
096
200
4
170
134
200
6
272
213
200
8
303
285
200
10
312
307
400
0
109
063
400
2
1.27
1.17
400
4
168
1.44
400
6
295
221
400
8
3.08
3.00
400
10
314
310
600
0
128
075
600
2
139
133
600 _
4
182
157
600
5
232
2.03
600
6
280
252
600
7.88
307
2.91
800
0
1.23
072
800
2
131
126
800
4
185
1.54
800
6
277
224
800
8
339
303
800
876
339
3.39
1000
0
129
0.75
1000
2
133
131
1000
4
1.77
152
1000
6
287
223
1000
8
346
312
1000
96
356
350
1500
0
148
086
1500
2
161
154
1500
4
189
172
1500
6
289
231
1500
8
363
320
1500
10
387
373
2000
0
161
0.94
2000
2
167
1.64
2000
4
202
182
2000
6
2.65
228
2000
8
374
311
2000
10
402
386
1 of6

Measured vs. Predicted Salinity
Distance Downstream of Confluence
with Herring Run (ft)
Depth below
Surface (ft)
Salinity measured
(4/13/2012)
Salinity Predicted
2500
0
189
140
2500
2
192
190
2500
4
203
195
2500
6
208
2.04
2500
8
3.76
2.52
2500
10
435
392
3000
0
187
138
3000
2
196
189
3000
4
207
1.99
3000
6
236
215
3000
8
396
278
3000
10
451
410
3500
0
167
124
3500
2
189
1.73
3500
4
207
194
3500
6
293
230
3500
8
394
320
3500
10
451
4.09
4000
0
176
130
4000
2
189
180
4000
4
220
197
4000
6
333
249
4000
8
413
354
4000
10
464
427
4500
0
182
135
4500
2
184
183
4500
4
219
193
4500
6
327
2.48
4500
8
408
348
4500
10
467
423
5000
0
192
142
5000
2
197
193
5000
4
244
209
5000
6
330
267
5000
8
420
353
5000
30
473
434
6000
0
204
151
6000
2
214
207
6000
4
255
225
6000
6
341
278
6000
8
4.51
369
6000
10
533
472
2of6

Measured vs. Predicted Salinity
Distance Downstream of Confluence
with Herring Run (ft)
Depth below
Surface (ft)
Salinity measured
(4/13/2012)
Salinity Predicted
7000
0
208
1.54
7000
2
224
213
7000
4
232
226
7000
6
345
262
7000
8
465
376
7000
10
534
483
8000
0
222
1.64
8000
2
227
223
8000
4
249
2.33
8000
6
398
288
8000
8
492
422
8000
10
539
SOS
9000
0
241
205
9000
2
250
242
9000
4
271
253
9000
6
409
291
9000
8
471
418
9000
10
5.34
481
10000
0
247
210
10000
2
2.51
248
10000
4
341
265
10000
6
427
354
10000
8
Soo
438
10000
9.1
548
508
11000
0
250
2.13
11000
2
255
251
11000
4
268
257
11000
6
395
287
11000
8
5.39
4.17
11000
10
586
5.46
12000
0
264
225
12000
2
301
270
12000
4
323
304
12000
6
4.05
335
12000
8
576
43
12000
10
607
580
13000
0
284
2.42
13000
2
311
288
13000
4
347
316
13000
6
501
370
13000
8
565
5.11
13000
10
610
5.72
14000
0
3.24
275
14000
2
328
324
14000
4
349
3.31
14000
6
4.87
369
14000
8
636
509
14000
9.3
645
638
3of6

Measured Salinity After Tropical Storm Beryl (5/31/2012)
Distance Downstream of
Confluence with Herring Run (ft)
Depth Below Surface
(ft)
Temperature
(°C)
Salinity Measured
(PSU)
0
0
20.84
0.03
0
2
20.85
0.03
0
4
20.85
0.03
0
6
20.94
0.03
1,000
0
21.00
0.03
1,000
2
21.00
0.03
1,000
4
21.00
0.03
1,000
6
21.00
0.03
1,000
8
21.00
0.03
2,000
0
21.05
0.03
2,000
2
21.04
0.03
2,000
4
21.05
0.03
2,000
6
21.05
0.03
2,000
8
21.05
0.03
3,000
0
21.13
0.03
3,000
2
21.14
0.03
3,000
4
21.08
0.03
3,000
6
21.08
0.03
3,000
8
21.06
0.03
4,000
0
21.08
0.03
4,000
2
21.12
0.03
4,000
4
21.10
0.03
4,000
6
21.06
0.03
4,000
8
21.07
0.03
5,000
0
21.16
0.03
5,000
2
21.13
0.03
5,000
4
21.14
0.03
5,000
6
21.11
0.03
5,000
8
21.11
0.03
6,000
0
22.07
0.04
6,000
2
21.35
0.04
6,000
4
21.41
0.04
6,000
6
21.35
0.04
6,000
8
21.18
0.04
7,000
0
22.01
0.04
7,000
2
21.23
0.04
7,000
4
21.25
0.04
7,000
6
21.20
0.04
7,000
8
21.22
0.04
8,000
0
21.87
0.04
8,000
2
21.70
0.04
8,000
4
21.47
0.04
8,000
6
21.36
0.04
8,000
8
21.44
0.04
9,000
0
22.17
0.04
9,000
2
21.54
0.04
9,000
4
21.35
0.04
9,000
6
21.20
0.04
9,000
8
21.38
0.04
4of6

Measured Salinity After Tropical Storm Beryl (5/31/2012)
Distance Downstream of
Confluence with Herring Run (ft)
Depth Below Surface
(ft)
Temperature
( °C)
Salinity Measured
(PSU)
10,000
0
21.76
0.04
10,000
2
21.47
0.04
10,000
4
21.34
0.04
10,000
6
21.35
0.04
10,000
8
21.33
0.04
11,000
0
22.55
0.04
11,000
2
21.87
0.04
11,000
4
21.72
0.04
11,000
6
21.38
0.04
11,000
8
21.37
0.04
12,000
0
22.40
0.08
12,000
2
22.92
0.07
12,000
4
21.53
0.04
12,000
6
21.40
0.04
12,000
8
21.42
0.04
13,000
0
22.95
0.05
13,000
2
22.32
0.05
13,000
4
21.67
0.04
13,000
6
21.53
0.04
13,000
8
21.50
0.05
14,000
0
22.70
0.05
14,000
2
22.39
0.04
14,000
4
21.88
0.05
14,000
6
21.42
0.05
14,000
8
21.38
0.05
15,000
0
25.10
0.06
15,000
2
24.47
0.06
15,000
4
22.27
0.05
15,000
6
21.79
0.05
15,000
8
21.50
0.05
16,000
0
25.02
0.08
16,000
2
22.60
0.08
16,000
4
21.67
0.06
16,000
6
21.61
0.05
16,000
8
21.60
0.05
17,000
0
24.30
0.07
17,000
2
21.99
0.06
17,000
4
21.74
0.06
17,000
6
21.65
0.06
17,000
8
21.61
0.06
18,000
0
25.66
0.17
18,000
2
23.65
0.21
18,000
4
21.68
0.09
18,000
6
21.75
0.11
19,000
0
26.17
0.10
19,000
2
22.09
0.10
19,000
4
21.98
0.11
19,000
6 1
22.20
0.11
5 of 6

Measured Salinity After Tropical Storm Beryl (5/31/2012)
Distance Downstream of
Confluence with Herring Run (ft)
Depth Below Surface
(ft)
Temperature
( °C)
Salinity Measured
(PSU)
20,000
0
26.58
0.25
20,000
2
24.76
0.16
20,000
4
22.26
0.30
20,000
6
22.30
0.32
21,000
0
26.31
0.28
21,000
2
23.77
0.20
21,000
4
22.82
0.43
21,000
6
23.48
1.00
22,000
0
26.97
0.46
22,000
2
22.80
0.37
22,000
4
23.32
0.90
22,000
6
23.45
1.05
23,000
0
26.23
0.39
23,000
2
23.20
0.43
23,000
4
24.03
1.23
23,000
6
24.11
1.24
24,000
0
26.79
0.48
24,000
2
26.32
0.57
24,000
4
24.30
0.99
24,000
6
24.04
1.19
25,000
0
27.16
0.81
25,000
2
25.68
0.75
25,000
4
24.30
0.91
25,000
6
24.05
1.13
261000
0
27.77
0.94
26,000
2
26.90
0.87
26,000
4
25.36
0.84
26,000
6
24.43
1.01
26,000
8
24.19
1.20
27,000
0
26.90
1.02
27,000
2
26.55
1.02
27,000
4
24.95
1.00
27,000
6
24.56
1.13
27,000
8
24.38
1.19
28,000
0
27.82
1.03
28,000
2
25.49
1.09
28,000
4
24.90
1.16
28,000
6
24.69
1.18
28,000
8
24.40
1.46
6of6

Attachment 2
GMA Aquifer Water Chemistry Sample Report

•10/62/2007 15:28 1- 252 - 758 -8835 GMA GREENVILLE NC PAGE 05/14
Environmental Chemists, Inc.
6602 Windmill Way o Wilmington, Nanh Carolina 28405
(910) 392 -0223 Phono a [phone] Fax
EChem Wkbol.com
Analytical & Consulting Chemists NCDENR: DWQ Certificate 04, IDLS Certificate #37729
NEW WELL INORGAMC CHEMICAL ANALYSIS Page 1 of 10
NoWMI inA�rtt�nbee anxkbeaaoa Por plan review eroaa
WATER, S7dST1 M IUD #: County: AeaQiort
Name of Water System: Almlin Marietta AgLM_tes
Sample Types. X Source for Plan Review
Location Where Collected: -
ot�:
Location Cade; Collection Date Collection Time
Collected I3y: Jay il(olley� «� n 0 S (/07/07 U �0��4�0 -M) AM
Mail Results to (water system representative):
GMA
20zS E�East� ate Drivve Phone #:
Greepy.L -e NC 27$50 _ _ Fax #: (, 1
LABORATORY w #: 3 7 7 2 9
0 SAMPLE UNSATISFACTORY
❑ RESAMPLE REQUIRED
CON T E
CONTAMINANT j
� 4U
REQUIRED ME Dr-TECTED I
REPORTING LMIT < RR4
QUANTIFIED ALIAS IF
(R.R.L.) .,.....�...........,M
E
0100
Turbidity
001
0.10
tutu ;
0
272. NTU
NIA -
1005
,A•xsenir,
125
0.005
M91L i
X
_ _mtz/L
0.010 mg/L
1010
Barium
169
0.400
mg/L
X
wgIL
2.000 mgl-L
1015
Cadmium
169
0.001
mg/L , -
13 , �_0 0 �, mg/L
_ 0.005 mg/L
1016
Calcium
169
0.001
rMS/L
GI
11.1 m� '
N /A,
1017
Chloride
17-8
5.0
mg/L '
©
7. melt.
250.0 mg/L
- _ - _ -
1020
Chromium !
1 6 9
0.020
mg/L
X
mgj
0.100 mg/L
1022
Copper ;
16.9.
0.050
mg/L
X
_
1300 mg/L
1024
cyanide
1 5 4
0.040
mg/L
X
mgll.
0.200 mg/L
1025
Fluoride
107
0.100
mg/L
13
0.4 mg/L
4.000 mg/L
1028
iron
169
0.060
mg/L
13
21. $ flL
0.300 mg/L
1030
Lead
125
0.003
mg/L
X
_ _ _ ___ xna/JL
0.015 mg/1..
1031
Magnesium
L§.2
1.0
M81L
0 -
_ 9.5 $ malL
N/A
1032
Manganese
169
0.010
mg/L
0
0.242 . mgj
0.050 mg/L �
I� 1035
Mercury
103
0.0004
ing/L
X
0.002 mg/L
-mtJ[,
►
for i d and C er arc action levels not MCia
# 16096' 7 -757'9
Note. Concentratton9 .cs �P

19/02/2007 15:28 1-252-758-8835 GMA GREENVILLE NC PAGE 06/14
Environmental Chemi-sL& Inc.
6602 Windmill Way o Wilmington, Norffi Carolina 28405
[phone] Phone a [phone] Fox
ECheMWL,()aQ1,-U—M
Analytical & Can-uhing Chemists NCDEM: J)WQ CerW'c4(A 494, DUS Certificato 937729
NEW UqMt INORGANIC CHEWACAL ANALYSIS Page 2 of 10
(Conti"Cd)
NW: Aff b,ft.. it ffA# besoWled fbr pine rtAuw cjo&
WATER SYSTEM ED Abirietta Coi!e-� On Date Collection Time
Location Code: -SpMt at well
00/07107 1
jMMIUUIVY) . 1 -40 AM
j.,41"IyAmerrm)- -
LABORATORY 10 N.- 37729
CONTAM
cow
C4DNTAMINANT
MET140 REQUMED
DCOI)t RMOR TING LWT i
=DETECTED 1
(; < R.RJ,)
Mb 15 units
1915
Total Hardness 1
141
-- ------ R,1tL
RF-SULfS
N/A
1925
---
.1036-.;
Nickel
1: 169 1
0.100,
mg/L
-
x
1927
Alkalinity
NIA
1040
Nib-ate
10 9 1
1.00-
m- g-/L,
x
139
10.0 mg/L
10.00 mg/L
1041 -.1 -------
Nitrite
109
0.10
x
M"
1.00 mg/L
1045
'40,50,
Selenium
125
.
0.010
mg/L:
X
1
0.050 mg/L
silver
I 69
mg/L I
x
moJL 1
0.100 mgq,
1052
Sodium
169
1.0
mgfL 1
go,
N/A
1055
Sulfate
i 137
5.0
mg[L
— •
2 50.0 WL
1069
Acidity
144
1.0
MAi ;
0
33.
mj
N /A.
1074
- --.. -..
Antimony
.1 125
--.
0.003
mg/L I
x I
Me/L:
0.006 mg/L
1075 J.
Beryllium
1169
0.002
JMgtL
x --------
M91
0.004 mg/L
1095
Thallium.
125
0.00 1
MA i
x
0.002, mg/L
1095
- -
Zino
169
........
I.o
m wi, 1
x
- -------
—m*L-i
M91
510 me/L
1905
Color
129
5 units
Mb 15 units
1915
Total Hardness 1
141
1.0 mg/L;
316.
N/A
1925
---
PH
N/A
N/A
C.I.A.
units 6.50 - 8.50 twits
1927
Alkalinity
14 2
0 91L:
.......
mPJL NIA
1930
Total Dissolved Solids i
139
10.0 mg/L
408.
'TOWL 500.0 mvJL
*Note: Concmaudons for Lead and Copper we gictign Icycls, not mcLs,
DATE:
ANALYSES BEGUN: 99/07/07 0 4: 50 PM
ANALYSES COMPLETED- I1 08/15/07 04:30 PM
Laboratory Log #: 16 0 9 6 " Certified By,
COMMENTS; 4,
fl— 1=757 9

10/02/2007 15:28 1- 252 - 758 -8835 GMA GREENVILLE NC PAGE 07/14
Environmental Chemists, Inc.
d 6602 V%rmdmiA Way a Wilmington, NC 28405
(910) 392 -0223 (Lab) o (910) 392 -4424 (Fax)
710 Bowsextow,n Road • Mantoo, NC 27954
ANALYTICAL & CONSULTING (252) 473 -5702
CHEMISTS NCDHNR: DWQ Ci3RnFICATE #94, DT-8 CERTIFICATE 037729
Customer.
GMA
2025 — E Eastgate Drive
Greenville, NC 27850
Attu: Jay Holley
1 F
WQAT OF ANALYS15
Date of RepoW. September 17, 2007
Purchase Order No.:
Report Number: 7 -7579
Date Collected: 08/07/07 Report To.- Jay Holley
Sampled By: James Volley Project: Martin Marietta Aggregates
I.D. 9 16096 Page 3 of 10
TRIHALOMEIMANE LORMATION POTENTIAL -- 7 Day Incubation
Chlorine Residual after incubation = 3.1 ppm C12 from a 30 ppoia►Dose
;TMITP nalysis
Chloroform mgtL — 0.216
Srolmofoa m mg/L = < 0.001
Chlo>rodibromaomnetbane mg/L _ < 0.001
Bromodichloromethane mg/L - 0.016
TFP mg/L = 0.232
4 hoar Cblorine Demand = 17.6 ppnt Ch
IIALGACE'TIC ACID p'GRMA'TIGN POTENTIAL — 7 IDay Incubatign
HAAI! P Analysis
Monochlore acetic Acid mg/L = < 0.002
Dieblalroacetic Acid mg/L = 0.051
Trichloroacetic Acid mg/L 0.058
Monebromoacetic Acid mg/L _ < 0.001
I9ibramoacetic Acid mg/L — < 0.001
TFP meg/L = 0.109
Reviewed by
r

10/02'/2007 15:28 1-252-758-8835 GMA GREENVILLE NC PAGE 08/14
14-n-irtrivny" i *-A r.
VOLATILE ORGAMC CMMICALS MALYSIS (VOCs) Page 4 of 10
WAFER SYSTEM ID County: Beaufort
Name Of Water System: - . M—aftrHarietta Agee min
Sample Type: 13 ZatryUnt X Spedal/Non-compliance
f•cation Where Collected: ftilot at well
Location Code.
Collected By.- —.lames HllmpliK)
Mail Results to (water system representative),.
2025 —E EnAzate Drive.
.-_GrftivvHte .WC 27>$.sil
LAl3oRAToRY ID #: 3 7 7 2 9
COMMINGO-TOR-Aft Q0.11ke-flop-3{'i me
or
Phone M
Fax #f: C— )
Cl SAMLE UNSATISFACTORY 0 RESAMPLE, REQUIRED
CONTAM
cm CONTAMINANT
MCEOMIX oD
RMRTrNQ MM
(WREAWNTLMTO ED
R. kt)
AULRWAIT ABLE
(".L.)
0)
2030
217
0.0005
'"91.�
X. "
� — —
N/A
2216
I Chlommethane
217
0.0003
M911-
. I — �—.
X
-
NIA
2212
-
0.
-66
4L
'
ic
NIA
221 4
Dz i; metlrana
2 17
6.'600-5*
mg/-
X,
—T — — — — — —
mg/L i
NIA
2216
7-
().0005
L
/-
X __ — — — — — —
qvL
N/A
221$
i RUOMUiChImmethafte
1 2 17
0.0005
mgll,
X -- ............. ........
mg/L
N/A
2246
j'ficiach6 buiadfeffc
217
0.0005
mg/L
X
mg/L
N/A
224$
217
0.0065
MWL
NIA
2378
1�4-Trioldmobcumo
217
0.0005
Ing/L
X — — — — — —
)L
0.07 M$/It
IS-U•MMOMAYIme
2-1-7-
0,0005
MSIL
X
M
0.07 mg/L
240$
Dibmmamcthane
217
0.()005
aw
mg/L
N/A
2414
1,i- Dichloropropene
217
0.0-005
mg/L..
- - - - - -
mgll.
N/A
2412
I,3Dichlnropropane
217
0.0005
mg/L
X
-
mg/L
2413
217
0,0005
mg/L
...
X --- - - - --
mg/L
N/A
24*14
17
0.6005
mil
X-
N/A
2,2•DicbImpropme
217
0.0005
MOIL
X - - - - --
Mr/L
N/A
2418
I,2A= lrimeHtyibcnzc�te
211
0.0005
mg/L
14/A
2420
1A3-Triebloroba z ' ma
217
0,605
MgIL
X
MOIL
N/A,
i422
-Vutylbv..ra
217
0.0005
Inv,
X __ — — —
Mg/L
NIA
2424
1A5-Trimed0benac
217
0.0005
mg/L
X
mg/L
NIA
2424-
TatrButylbemme
217
0.()005
"WL
X — — — — — —
mg/L
N/A
2428
SCC-BUtYjbCn7.MO
217
0.0005
Mg/r.,
X -- — ---
mg/L
NIA
2430
Broma6lommctfianc
217
0,0005
mg/L
X
mglL
N/A
2941
Chloroform
217
0.0005
mg/L
X
M 911,
NIA
*Note: if result exceeds allowable limit,
the laboratory must fax analytical results to the State within 49 hours
## 16096 7-7579

10/02/2007 15:28 1-252-758-8835 GMA GREENVILLE NC PAGE 09/14
jLny ownenTm unemists, ing.
_
6602 Windmill Way. Wilmington, Xortb Camlins 2805
4= jL
0 [phone] Phone • [phone] Pax E-CheniWOgol.com
Analytical 8t Consulting Chemists
NCDENR'DWQ Certificate #94. DLS Certificate 037729
Laboratory vAg #: 16 0 9 6.
# Z- 7 5 Z 9
CONIMNIM.
VOLATILE ORGANIC CHEMCALS ANALYSIS (VOCO) Pages of 10
Note: A11 infoanWn mat bsmMlied for 0Q"lWC* *WjtC4DfftjUVCd)
WATER SYSTEM YD 0. Martin Akr
Collection Date
C
_911ection:[ime
Location Code; wen
01107/, 07
-AM
(Mlvpj"w)
LABORATORY 10 6: 37729
CONTAM bun]=
CONTAMNANT
REQUIRED 1MDET8W=Mv I
P"ORTWOLUM ABOVE ILR-L
QUANTHqW
Resuvs*
ALLOWABLE
LuArr
CODE
CODE
(FULL)
2942
Hromofbrm
217
0.0005 mg/L
x
----mp)L
N/A
217
0.0005 nW
X
v#L:
N/A
2944
i ChlowdibromomOhane
217
x
N/A
~
217
0,0005 mg/1
'm"
x
— — — — — — mg/L.
10.00 mg/L
i r3lchla ntncthane
217
0.0005 g'AL
X
— — — -- - 1.
_0.005._ mg/L
2965
o-Chlowtolvene
217
0.0005 mg/L_,
X .
.. . . . . . nWL
N/A
2966
217 1
0.0005
x
Mg/L
N/A
2967
217
0-0005 mg/L
x
mg/j,
N/A
9�6i
-.
6005 mg(j,
x
0*1L
0.60
- .
p.Dj�;
21 7
0.0005
a#-L-
2976
VinylChloride
217
X
mg1L
_010-0-2. T#L
2977
1,1,- D;ettlorncthytcnc
217
0.0005 mg/L
x
0.007 mg/L
297
217
),L:
O.M5 Ipp
X
/L
!ny
N/A _.
2979
217
0_000 !jwL
j�
tn?�L
0.10 mg/L
29$0
1,2- laid►ltmnctltane
217
0.0005 MA
x
0.005 mg/L
29$1
1.t.Il- lrichJorocthane
217
6.605 1141..
x
L
0-io 1119/L
2982
Cwbon Tctmchlotide
217
0.0005 94/L
x
!qg/-L
217
0-OW5 W91L
IL
!)p
U05 mg/L
X
0,005 mg/L.
2985
1.1,2-Tticliforoethms
217
0.0005 m►&
x
mg/L
0._00_5 mo,
2986
1,l,1,2-Tdmhlorodhane
217
00005 nig/L
x
mg L
N/A
i9i -T
idftn�mof�Oyjguc
2i7
0.0005 mg/L
:k"
nigh,
0,005 mg/L
1,1",? Tetrachlorodhanc
217
0.0005 mg/L
x
HOL J
NIA
29
217
0-0605 MUIL
— — --- — — mv,�,_
0,10 mg/L
217
0,005 mg/L
x
mg/L
0.005 M911,
2991
Toiuetre
217
0.0005 mg/L
x - --
— — — — -- T91L
1.00 mg/-L
2902
Ethilb-came
217
0.0005 rtig&
0.70 mM,
2093
Bwu4cnzcn - a
21-7
0.0005 mg/L
x
ITWL
NIA
2004
- I I iopf*pylbcnzcnc
217
0.0005 mg/L
x - --
-- — — — -- mg/L
N/A
*6
Styrene
217
0_605 mg/L
x
mg/L
0.10 rnvt.
2998
n-Propylbunzcno 217
0,0005 U191L x -- •....._....._._.... — mgt-
N1A
*Nfj�: if towable limit the laboratory must fax andYtical results
tatc
to 1110 S within 48
h%
DATE,
T MR,
. S .B EG . UN-1
0 8 0 8 7
11: 00 Vl
ANALYSE
—0
':
ANA•L,vsES COMPETED: 1
08/13107
12 00
Laboratory vAg #: 16 0 9 6.
# Z- 7 5 Z 9
CONIMNIM.

10/02/2007 15:28 1- 252 - 758 -8835 GMA GREENVILLE NC PAGE 10/14
PESTICIDES AM SYNTHETIC ORGANIC CHEMICALS ANALYSIS (S®Cs) Page 6 of 10
Nose. nlunfommaon molt be RWUcd &rcmn0imvc credit
WATER, SYSTEM YD #: county: Beaufort,
Name of Water System: Martin MariettaA22[gmtcs
Sample Type: 0 Entry point X apecialMon- catnplRance
Location Where Collected:
Xseation Code:
Collected Icy: .Fames noon
Mail Rents to (water system representative):
GMA
20 – E Eastnte Drive
jpeu'viile. NC 27850
CCo ec -00". Date COilectiou Time
Phone
Fax #: (C- }. -_...
LABORATORY W #: 3 7 7 2 9 13 SA114F'LE UNSATISFACTORY 0 RMAWLE REQUIRED
REQUIRED ZM DETECTEb
CONX/lM CONTAMINANT MBfHQD RUMTIWUNIT o. <xRx : ALLOWABLE
CODE CODE m R t.1 nri ' QPMUA LLTTSS*D LZQT
2005
2010
2015
2020
2021
2022
2031
2035
2036
2037
2040
2041
2042
2043
2044
2045
2046
2047
2050
2051
2065
Endrin
2�0
! 0.00001
uw/L
X
-- — to
Liudanc
210
D -oom
mg/L
x _ -_
- _
fnglL '
Nlethoxycitfor
210
p.0001
mg/L
X —
In ,
.
Toxaphene
2 1.0
0.001
mpjt,
X —
i
Carbatyl
2 3 5
0.004
mg/L ,
X
mg/L
methomyl
2 3 5
0.004
mg, '
X — —_
mg/L
Dalapon
203
0.001
mgIL
x
7p ,
Di(2-ethy1hcxy1)adip3t0
225
0.0006
mgt. '
X — -
- -- Th
CTxamyl(vydate)
2 3 5
0.002
m' g(L' ;
X _
- -_ ffig/L '
SimaAne
2 10
0.00017
mg/L
X — -
-- _ tt WL
Picloram
203
0.0001
mg/L
X --
-- _.. _.
nWL ,
riinoseb
22 63
0.0002
mg/L
X
mgn
Y 1rctachlorocyar0pcutadicttE
2 1 0
0.0001
n1)L ;
X
•--
Aldicarb
235
0.0005
Mg/L. ,
X _
_ _ mom.
AldicarbSu6ne
235
0.000$
tngi'
X
mil[.
Metolachlor
210
0.0008
ME&
X —
mg/L
Carbofuran
2 3 5
0.0009
mg/L
X
Aldicarb
235
0.0005
mg/L
x --- — —
- • • • mom,
Atrazinc
210
0.0001
mg/L
X w�
— — mgli,
Alachlor
2 1 0
0 -0002
mg/L
X -- - - -
- -- MeL
Heptachlor
210
0.00004
mg/L
X
* Note: rfresult excecds allowable limit, the 111130retory must flIX analydeal results
to th0 Stote within 48 hours.
# 1 6096
0.002 mg/L
0.0002 mg/L
0.04 mg/L
0.003 Me,
X/A
N /,A.
0.2 mg1r,
0.4 ing/L
0.2 mg/L
0.004 mA
0.5 mg/L
0.007 mill•.
0.05 M84-
N/A
9/A
N/A
0.04 mg/L
N/A
0.003 MO l
0.002 mgJL, ti
0.0004 mg/L J1
77574

10/02/2007 15:28 1-252-758-8835 GMA GREENVILLE NC PAGE 11/14
Q 1-mew
PESTICMES AND SYNMT14C ORGANIC CHENUCALS ANALYSIS (SOCs) Page 7 of 10
Now, An faftmgdon --'ICVW-d &I ammlimror -aft
WATER SYSTEM IUD
-MXft,NLa&_tMAMgjLte9 Collection Date ime
Loeation Code: WCH 2 4.4 9 710 7 0 AM
II Q4rd/&RNV V)
X420RATORT IV #; 3 7 7 2 9
II CONTAM ! METHOD REWHOU : X4?jDHj-F: I QUANTIM-0 AUDWABLE
CIONTAMMANT RwjkTMLWT i ABOVERAL. :
C CODE PESULTSO LMOT
CODE : I long% rv% 11
2066
3-1T boft=
.-
206'7 "
1 HqftcW0rfij7o#de
2070
Dieldrin
;'Butad'dor
2617
i RVaddor
2A5-TP (SilvcO
Hmchlorobmme.
4208
.
1! Di(2-cthy,,jcXyj)phthafttc
bm
ienzowpyrcnd
2326-
2356 -
2440 '
2959
Chlordane
*Note' dresultc cccdq 811mable
limit MWL
2 �10 0.0002 mg1L
�1- 0.008 MYJL L
-6-
210 1
-.0-000).
203 0.0002 mg/L z
210 0.0001 MVL
225 0.00132 M91L
0.00002 -0 W2 M91L
.203
21*6 0.00-02 mg/L
U-0 0.0001 mglL
203 1 0.001 mg/L
210 0.0008 mg/L
2 0.00002 mg/L
2.1-0 0.0007 mg1L
1114 Iftbomtory must fax fmamical msu
x N/A
x 0.0002 - mg/L
--- ----- -
X mjy)L N/A
x — — — — — — NIA
x
x _ __ mg/L, ' 0.07 ma
x tn&/L 0-05-- 0)9lL-
x mg/L_' 0.001 mg/L
x mg/L :. 0.006 ma
x mg/L! 0.0002 mgfL
x - - - - -- ing/C, 0-001 mg/L
X
x -- — — -- — — m&fL 0.0005 mg/L
R -mg1L N/A
x MeL
mg/L 0.0062 . MWL
X mg/L 0.100005 mg(L
x 0,002 mg/L
s to thr, Sta(c within 48 hours.
DATE: T :
ANALYSES BU,GW. 08/08/07 07:00 AM
ANALYSES comeLSTED: 08123L.0 �7 d 2_., _..0... Woo" I
Laboratory Log #: 160.96
(Nint and sign nmnc)
- "-/ -,z
COMMENTS:
REPORT#
1114 Iftbomtory must fax fmamical msu
x N/A
x 0.0002 - mg/L
--- ----- -
X mjy)L N/A
x — — — — — — NIA
x
x _ __ mg/L, ' 0.07 ma
x tn&/L 0-05-- 0)9lL-
x mg/L_' 0.001 mg/L
x mg/L :. 0.006 ma
x mg/L! 0.0002 mgfL
x - - - - -- ing/C, 0-001 mg/L
X
x -- — — -- — — m&fL 0.0005 mg/L
R -mg1L N/A
x MeL
mg/L 0.0062 . MWL
X mg/L 0.100005 mg(L
x 0,002 mg/L
s to thr, Sta(c within 48 hours.
DATE: T :
ANALYSES BU,GW. 08/08/07 07:00 AM
ANALYSES comeLSTED: 08123L.0 �7 d 2_., _..0... Woo" I
Laboratory Log #: 160.96
(Nint and sign nmnc)
- "-/ -,z
COMMENTS:
REPORT#
DATE: T :
ANALYSES BU,GW. 08/08/07 07:00 AM
ANALYSES comeLSTED: 08123L.0 �7 d 2_., _..0... Woo" I
Laboratory Log #: 160.96
(Nint and sign nmnc)
- "-/ -,z
COMMENTS:
REPORT#

• J
10/132/2007 15:28 1- 252 -758 -8835 GMA GREENVILLE NC PAGE 12/14
Environmental Chemists, Inc.
6602 Windnull Wtn- a Wil itigtun. North Carolina 28461
(910) 39241223 Phone • 19101.192 -442.4 F.ix
Lit =hctnW r► ;1��1.c_t�m
Anall%lical & Consttltitig C'hettuylR NCDiENR: 1DWQ Certificate #94, DLS Certificate 637729
.- �.....- __•_.. -... _:.......,...:. �.--,----- �--_--_.....,.....-BACTERIOLOGICAL ANALYSIS
c
Note: 41Lapmpriatc information must be supplied for complinnce credit. � ek
Water Systein AID #: _ - - W - --- - County:
i+iame of water System: ' Akal, 14,, A'F ar ;G A,spi-9 a 4 ,l•et Pro "-K
SAMPle IYpes ❑ Routine distribution 0 Repeat 0 Plan Review -0 Special/Non -compliance
Location
Location
Collected
Wail Rewults -tam• (water system mpresent; -I ive))i:
M
g re4n vrLlr� a '7 g'J
']rode No.: -7 3 % C�
Previous !Positive Location Code:
Previous Collection Date: _ _ / _ _ /
Proximity of THLS- sample to Previous )Positive:..__.
❑ Sattte Tap D Nearer to the Source 0 Further from the Source
If Chlorinated: Total Chlorine Rcsidua -, mg/L
Free Chlorine Residual: mg/L
tesponmolo Prx onn Lrtnau: Combined Chlorine Residual: mg/L,
C • CO (Corm6ined (:Murine •^ larot Chlarina o1 i lm rrea /„Molina)
Note: Alao record ihoae valuft on your water Imp report.
E3 Repeat Samples Required from Client
- aboratory I1D#: 37729 ❑ Resample required from Client
1USULTS
,0NI'AKNAN1' M1" I'I fUD CODE
PRESt;,NT"' ABSENT 1NVALID CODE H' I) Ci)nlluent UrowflWo Colifonn Growth Found
'otal Coliform 3 1 2 2) - fl3'iC/No colitolm. (;roth Pound
i) Turbid (Mite No coliform Growth 1,ound
4) Over .10 Hovers 0141
Mcrotrophic P.C. _ cftt/n1L S) Improper satnple or Analysis
.. number
Notch Ir7'otat cwtirorm Anclorin is presattl, the laboratory must fax analytical rat 11c lot the Slate within AS hoar.;.
' f Nunl /t. Coli bacleria La preaegt, the laboratory must fix unalylic:tl rosults to tile State oil day toot atmpletert,
' tnvali(l -samples (code 95) shotlld be n000mponiod by an oKpinnation in the cornnccoW below.
Analysis Begun: Z / C -? _ 3
...+......- ...— '- �w«wru. maws ..�.w+•+...�......�.....�..+.w. .�.�.+�,..........e.,s �....�..d
Analysis Completed: _ �/ _� / �✓_ � � �� - �.► -t�' � __M
Aborafory Lei ✓f' lS�v f �m Cortificd By.�,— J- 1 L. �;' r t�
SP6111 ;Ind Nip Nn ue) u �� -�~ - —
r )NIP�,•rF'N l :5:
ottle 11) # TURBIDITY, 4 - - - _ - -- - - -
ORO

10/02/2007 15:28 1- 252 - 758 -8835 GMA GREENVILLE NC PAGE 13/14
' Florida - oc�. � S
-vices, Inc.
5456 der Aw,, SWft 201 Q b FL 32812
pbam Oar 310-IM Ph= (40*82 -x`744 Page 9 of 10
RADIOLOGICAL ANALYSIS
Note. a h maUen meat be mipplied En eempum= otdit
WATEIR SYSTEM 10 #: _. -- .._ .. _ _ Coo p#.- /L
Name of Water System: &Vrcj� -•' f
Sample Type: 0 Distribution O fttay 1Point O Composite *Recial/Non-complivance
Mail Results to (system repmentative):
Telephone #_ (___j
Fax #:
p'.4w i
$Inge or
.rte lm- Saewplc
VAM-um Cade lOMOM
eoueered
BY
✓ Y7`
4'* Q* I .. _ !_.. r.— —M -- --
LABORATORY 11D #: 1 2 7
0 9
0 SAWLE t( NSA-17 VAC TRY 0 RESAMPLE REQ[I REA
CONTAM
CONTAMINANT
D
. _
QuAN[tFtlrn
COUNT NAQ
ERROR
ALLOWMMX.
ukirr
CODE
(ILRL-)
p0
RESULTS*
4000- (JOV7- Gross Alpha
435
3 pCi/L
0
— f'�. pCVL
_ -�• .�.
15 pCVL
4004
Radon
N/A
100 pCi/L
13
_ _ pCi /L
_//---
N/A
4006
Uranium
456
2 pci/I.
E3
. 2? .. pCl/L
— _1...1
20.1 pOIL
4010
Combined Radimn
NIA
NIA
N /,A.
_ _ _ _ — PC,/(.
__
5 pCVL
4020
4030
Radium 226
stadium 228
446
452
1 pC:i/L
1 poll,
AL
- -- -- pci/L
pCi/L
da.• 1 _
� •
3 pCi/1..
2 pCi/IL
4 100
Gross Beta
435
4 pCi/1.
_. _ pCi/L
±
50 pCi/1-,
4102
Tritium
N/A
1,00() pCi/L
13
_ - -- - pCUL
- -- _ - --
20,(x)0 pCill.
4172
Strontiurn 89
N/A
10 pCi/L
13
- -- -- pCi/l.
-- r _
N/A
4174
Strontium. 90
425
2 pCiA,
13
-- -� pau>r
- •- - -- --
8 pCl/L
4264
iodine 131
N/A
1 pci/L
0
_ . _ , ^ _ pCUL
_ _ . , ,,.
NIA
4270
Cesium 134
N/A
to pod
0
_ -_ - - oCVL
-- -
N/A
- -_
"Note: If result exce ads- allowable limit, the laboratory must fax analytical results to the State within 48 hours.
DATE: 'LIME.,
ANALYSES BEGUN., c} � l -Ltv I b �.W. !i iv Z. � X m
INU.AdY'It) IfM�jA a.l^.A
ANALYSES COMPLETED' �} c��I �+ 7-1 Li M
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Date: October 10, 2012
Project: Vanceboro Site
Martin Marietta Materials
Craven and Beaufort Counties, North Carolina
Subject: Flood and Stability Analysis
Purpose
The following Technical Memorandum is prepared to summarize the results of analyses performed to address
the North Carolina Division of Water Quality ( NCDWQ) and United States Army Corps of Engineers
(USACE) comments regarding stream stability and potential flooding issues associated with the proposed
addition of the quarry dewatering discharge to Blounts Creek from the proposed Vanceboro Site. This memo
also will provide Coastal Zone Resources (CZR) with predicted zones of potential impacts so the company
can further analyze the potential impacts to essential aquatic habitats for fish, benthic invertebrates, and
vegetation.
This Technical Memorandum was originally submitted to NCDWQ as a combined report titled "Stability,
Flood, and Water Quality Analyses ", dated September 6, 2012. This amended memorandum has been
prepared to clarify comments received by reviewing agencies that combining the flood and stability analysis
with the water quality analysis created some confusion. Included herein are the flood and stability analysis
only, as well as an addendum with additional information and figures in response to comments provided by
the NC Division of Marine Fisheries (NCDMF) and NC Wildlife Resource Commission (NCWRC) at a
September 21, 2012 meeting held in the NCDENR Washington Regional Office.
Background
The estimated maximum discharge rate from quarry dewatering is approximately 18 cfs (approximately 12
mgd). As part of the application and review process for the Individual 404 Permit, the associated Water
Quality Certification, and the NPDES Discharge Permit, regulatory agencies raised several concerns related to
stream stability and flooding.
Kimley -Horn and Associates, Inc. (KHA) gathered additional existing conditions data to assess flooding
potential and stability throughout the Blounts Creek system. To assess the data, KHA used HEC -HMS,
HEC-RAS, and spreadsheet models. The data collection and analytical methods are discussed in detail in the
attached documents and summarized below.
C•/1 Kimley -Horn 1 of 14
and Associates, Inc

Flooding— Residents of the Cotton Patch Subdivision have expressed concerns that the additional
discharge from the quarry may affect flood elevations near the subdivision. The flood study within this
document found that the addition of 18 cfs of discharge will have little effect on flood elevations.
Stability—NCDWQ has concerns that the upper reaches of Blounts Creek may experience excessive
erosion from an additional 18 cfs of continuous discharge. KHA performed additional analysis that
indicated the effect of splitting the discharge of 18 cfs between the two outfall locations at a maximum 9
cfs ( -6 mgd) at NPDES Outfall 001 and 9 cfs ( -6 mgd) at NPDES Outfall 002 should, at most, result in
only small changes to the channel geometry of the upper reaches of Blounts Creek.
E:fi• Kimley -Horn 2 of 14
M and Associates, Ina

Table of Contents
1.0 Flooding and Stability Analysis ....................................... ............................... 4
1.1
Background .............................................................................. ..............................4
1.2
Methods ................................................................................... ..............................4
Figure1 -1: Model Layout Map ............................................. ............................... ...........................5
1.3
Results and Discussion ............................................................. ..............................6
Table 1 -1: Flood Analysis WSEL Comparison .......... .. ............................... ...... ..............................6
Table 1 -2: Flood Analysis Velocity Comparison ............................... ..................... ..............................7
Table 1 -3: Permissible Shear Stress and Velocity ....... ............................... .......... ...............................
8
Table 1 -4: Blounts Creek Model Results Compariso ................................................ ..............................9
Table 1 -5. UT -2 Model Results Comparison ........................................................ .............................10
1.4
Conclusion .............................................................................. .............................11
References.............................................................................
...............................
12
Addendum.............................................................................
...............................
13
Attached: Model Results Comparison Tables
Kimley -Horn
® and Associates, Inc. 3 of 14

1.0 Flooding and Stability Analysis
1.1 Background
The NCDWQ requested that Martin Marietta Materials evaluate the effect of the quarry dewatering
discharge from the proposed quarry on the stability of Blounts Creek. Local community members
near the Cotton Patch subdivision also have expressed concern that increased flow from the quarry
dewatering discharge may have an adverse effect on flooding near their property. KHA performed a
detailed hydrologic and hydraulic analysis to the stability and flooding concerns. To address both of
these issues, KHA determined that it would be necessary to develop an unsteady state HEC-RAS
model using hydrographs generated from HEC -HMS. Future conditions scenarios analyze a steady
discharge of 18 cfs (approximately 12 mgd) at the proposed quarry site.
1.2 Methods
Hydrology —The HEC -HMS model used the SCS synthetic unit hydrograph to create flow
hydrographs of the 1 -, 5 -, 25 -, and 100 -year 24 -hour- duration storms. Hydrograph parameters
of loss, transform, and depth were input using the following sources: runoff volume was
calculated using composite curve numbers from land use coverage KHA generated using 2010
aerial photography, lag times were calculated using the SCS Lag Time Method, and precipitation
depth was taken from NOAA Point Precipitation Frequency Estimates for the station located in
Washington, NC.
Since there are no tide gauges located on the Pamlico River, daily tides were assumed to be
diurnal with a maximum amplitude of 1 foot and mean sea level at 0.00 ft NAVD 88. It is
possible that there is no observable diurnal tides based on observations from local residents, but
the tides were added as an additional conservative analysis. Surge hydrographs were developed
using methodology described in HEC -25 Tidal Hydrology, Hydraulics, and Scour at Bridges and
data from the effective Flood Insurance Study (FIS) of Beaufort County, NC.
Hydraulics —The HEC-RAS model was created using field measurements of cross - sections, ditch
widths /heights, pipe inverts, and soundings. Ditch widths /heights and pipe inverts were
measured on the proposed mining site, eight stream cross - sections were measured on
Weyerhauser property downstream of the proposed NPDES discharge point (two were taken
from previous studies), and four soundings of Blounts Creek were taken below the confluence of
Blounts Creek and Herrings Run. Cross - section measurements were only taken for the stream
section and LIDAR was used to supplement floodplain geometry. Additionally, since field
measurements were taken based on temporary benchmarks, elevations were tied into LIDAR as
best -fit approximations. To supplement the reach of Blounts Creek from the last Weyerhauser
property cross - section to the Herrings Run confluence, the effective FEMA HEC-RAS model of
Blounts Creek beginning at NC -33 was included.
A layout of the HEC-RAS model centerline and detailed areas of interest for the Flooding and
Stability analyses is shown below in Figure 1 -1. Note: only layouts of cross sections referenced in
this memo are shown on the figure.
C ® Kimley -Horn 4 of 14
®� and Associates, Ina

FLOODING ANALYSIS
iii
.0,
I
AL
STABILITY ANALYSIS
1.5
i ;nn f..t

1.3 Results and Discussion
1.3.1 Flooding
The hydraulics of the Pamlico River at Blounts Bay play a significant role in the hydraulics
of Blounts Creek, especially at the Cotton Patch subdivision. Since information on the
elevations of the Pamlico River during storm events is limited and because rainfall can be
spatially determinant (meaning rainfall can be localized or systemic across multiple drainage
areas) a variety of rainfall and downstream boundary condition scenarios were chosen to
cover a wide range of possible hydraulic conditions at Blounts Creek. Those scenarios
include 1 -year storm with assumed daily tide, 5 -year storm with assumed steady downstream
elevation of 0.5 feet, 25 -year storm with friction slope of 0.01 %, and 100 -year storm with a
synthetic surge hydrograph downstream boundary condition. Tables 1 -1 and 1 -2 (below)
show the output of these four scenarios and the resulting Water Surface Elevations (WSELs)
and velocities, respectively.
Table 1 -1: Flood Analysis WSEL Comparison
Feet above Blounts Bay
2 Estimated daily tide with amplitude of I ft at Blounts Bay
3 No change in downstream water surface elevation (set at 0 5 ft)
4 Downstream friction slope ofO.OlYo
5 Theoretical 100yr surge stage hydrograph based
* Confluence of Blounts Creek with Herrings Run
** The Cotton Patch subdivision
Note: Ex = Existing Conditions; Fu = Future Conditions, A = Difference between future and existing conditions. All elevations
are in feet and referenced to the North American Vertical Datum of 1988 (AA VD 88)
C:M / \ Kimley -Horn 6 of 14
®and Associates, Inc.
1 -yr
5 -yr
25 -yr
100 -yr
River
(Tides Z)
(No Tide')
(Friction Slope
4)
(Surge 5)
Station
Ex
Fu
A
Ex
Fu
A
Ex
Fu
A
Ex
Fu
A
28600*
0.96
0.97
0.01
2.24
2.26
0.02
4.71
4.73
0.02
9.30
9.31
0.01
25000
0.76
0.77
0.01
1.60
1.61
0.01
3.84
3.86
0.02
9.13
9.14
0.01
15900**
0.57
0.57
0.00
0.82
0.83
0.01
2.68
2.69
0.01
8.95
8.95
0.00
7000
0.50
0.50
0.00
0.50
0.50
0.00
1.87
1.87
0.00
9.20
9.20
0.00
Feet above Blounts Bay
2 Estimated daily tide with amplitude of I ft at Blounts Bay
3 No change in downstream water surface elevation (set at 0 5 ft)
4 Downstream friction slope ofO.OlYo
5 Theoretical 100yr surge stage hydrograph based
* Confluence of Blounts Creek with Herrings Run
** The Cotton Patch subdivision
Note: Ex = Existing Conditions; Fu = Future Conditions, A = Difference between future and existing conditions. All elevations
are in feet and referenced to the North American Vertical Datum of 1988 (AA VD 88)
C:M / \ Kimley -Horn 6 of 14
®and Associates, Inc.

Table 1 -2: Flood Analysis Velocity Comparison
Feet above Blounts Bay
2 Estimated daily ude with amplitude of ]fiat Blounts Bay
3 No change in downstream water surface elevation (set at 0.5 ft)
a Downstream fiction slope of 0.01 %
s Theoretical 100 yr surge stage hydrograph based
* Confluence of Blounts Creek with Herrings Run
** The Cotton Patch subdivision
Note: Note: Ex = Existing Conditions, Fu = Future Conditions, A = Difference between future and existing conditions. All
values are velocity in feet per second (fps).
The modeling results show that there is no significant change in water surface elevation and
velocity at the Cotton Patch subdivision due to the proposed quarry dewatering discharge.
Variations shown in the model are less than the effects wave action or wind tides would
produce.
1.3.2 Stability
Naturally stable coastal streams typically have mobile stream beds and deformable banks.
This means that during the runoff events from most storms the bed and banks will change
their shape. These changes are minor and normally do not result in bank failure, vegetation
loss, or excessive erosion. For a stream to be characterized as unstable, these changes would
need to be more dramatic and result in excessive erosion, bank collapse, and vegetation loss.
DWQ asked MMM to provide some analysis to assess whether adding the dewatering
discharge of 18 cfs would cause the existing streams to become more unstable. The following
analysis is based on splitting the discharge between NPDES Outfall 001 and NPDES Outfall
002 such that they are receiving 9cfs (�6 mgd) each.
To determine the effects of the proposed quarry dewatering discharge on the 'stability of
Blounts Creek, it is necessary to analyze channel shear stress and velocity. Bed mobility and
bank deformation of the existing channel is likely to occur when shear and /or velocities in
the channel rise above threshold levels that have been shown to be the limits of maximum
C FI Kimley -Horn
7 of 14
1 -yr
5 -yr
25 -yr
100 -yr
River
Tides z
(Tides
(No
Tide 3 )
(Friction Slope
4 )
(Surge 5)
g
Station'
Ex
Fu
A
Ex
Fu
A
Ex
Fu
A
Ex
Fu
A
28600*
0.85
0.87
0.02
1.60
1.62
0.02
2.08
2.09
0.01
0.58
0.60
0.02
25000
0.62
0.63
0.01
1.32
1.33
0.01
1.84
1.84
0.00
-0.29
-0.26
0.03
15900 **
0.34
0.35
0.01
0.79
0.80
0.01
TM.1.10
' 1.11 ^
0.01
-0.68
-0.67
0.01 `
7000
0.00
0.00
0.00
0.00
0.00
0.00
0.90
0.90
0.00
-0.57
-0.57
0.00
Feet above Blounts Bay
2 Estimated daily ude with amplitude of ]fiat Blounts Bay
3 No change in downstream water surface elevation (set at 0.5 ft)
a Downstream fiction slope of 0.01 %
s Theoretical 100 yr surge stage hydrograph based
* Confluence of Blounts Creek with Herrings Run
** The Cotton Patch subdivision
Note: Note: Ex = Existing Conditions, Fu = Future Conditions, A = Difference between future and existing conditions. All
values are velocity in feet per second (fps).
The modeling results show that there is no significant change in water surface elevation and
velocity at the Cotton Patch subdivision due to the proposed quarry dewatering discharge.
Variations shown in the model are less than the effects wave action or wind tides would
produce.
1.3.2 Stability
Naturally stable coastal streams typically have mobile stream beds and deformable banks.
This means that during the runoff events from most storms the bed and banks will change
their shape. These changes are minor and normally do not result in bank failure, vegetation
loss, or excessive erosion. For a stream to be characterized as unstable, these changes would
need to be more dramatic and result in excessive erosion, bank collapse, and vegetation loss.
DWQ asked MMM to provide some analysis to assess whether adding the dewatering
discharge of 18 cfs would cause the existing streams to become more unstable. The following
analysis is based on splitting the discharge between NPDES Outfall 001 and NPDES Outfall
002 such that they are receiving 9cfs (�6 mgd) each.
To determine the effects of the proposed quarry dewatering discharge on the 'stability of
Blounts Creek, it is necessary to analyze channel shear stress and velocity. Bed mobility and
bank deformation of the existing channel is likely to occur when shear and /or velocities in
the channel rise above threshold levels that have been shown to be the limits of maximum
C FI Kimley -Horn
7 of 14

permissible shear and velocity in stable stream channels. Table 1 -3 below summarizes two
bed materials from Table 7- 3— Maximum Permissible Velocities Recommended by Fortier
and Scobey and the Corresponding Unit - Tractive Force Values Converted by the U.S.
Bureau of Reclamation in Open - Channel Hydraulics (Chow, 1959); it shows an estimate of
the maximum nonerodible velocities in old and well- seasoned channels based on channel
material. Pebble counts performed in previous studies by KHA estimate bed material to be
an organic silty loam. Because there is a significant amount of organic and clay material in
the channel substrate, maximum permissible velocity and shear was assumed to be
somewhere between non - colloidal silt loam and colloidal alluvial silts. The average value of
the two soil types are shown in Table 1 -3 as the estimated maximum value.
Table 1 -3: Permissible Shear Stress and Velocity
Maximum Permissible
Values
Shear (lbs /ftZ)
Velocity (fps)
Non colloidal Silt Loam
0.05
2.00
Colloidal Alluvial Silts
0.26
3.75
Estimated Maximum'
0.15
2.5
' Estimated maximum permissible shear and velocity for the study area of
Blounts Creek
Low flow was estimated using the Coastal Plain 30Q2 for Clay Soils in Table 2 of USGS
Water - Supply Paper 2403 Low -Flow Characteristics of Streams in North Carolina (USGS,
1993). The 30Q2 is the annual minimum average 30 -day consecutive low flow that has a
50% chance of occurring in a given year. The 30Q2 flow is equivalent to 0.032 cfs per
square mile drainage area or approximately 0. 14 cfs at Blounts Creek just downstream of the
NPDES discharge point. The future conditions model included a constant flow of 9 cfs at
both Blounts Creek and UT2 to simulate splitting the maximum proposed quarry
dewatering discharge between the two reaches.
For stable coastal plain streams, instability does not necessarily occur when flow overtops the
top of bank. The study reach of Blounts Creek has excellent access to the floodplain;
therefore, incremental increases to discharge above the maximum channel discharge capacity
do not have incrementally large increases in shear and velocity. Erosion occurs at elevations
higher than bankfull as velocity and shear increase due to flood stages surcharging above the
bankfull stage. To determine the effects of the dewatering discharge on storm events, the 1-
year 24 -hour storm was modeled in HEC-RAS.
C ®/J Kimley -Horn 8 of 14
-► \ and Associates, Inc.

Model results are shown in Table 1 -4 for the reach of Blounts Creek from approximately
500 feet downstream of the proposed NPDES discharge point to the last cross - section on
Weyerhaeuser property.
Table 1 -4: Blounts Creek Model Results Comparison
1 Feet above Blounts Bay
Z Last cross - section on Weyerhauser property, approximately 7250 feet upstream from Tripp Road
Note: Ex = Existing Conditions; Fu = Future Conditions, d = Difference between future and existing conditions. Highlighted
cells exceed the estimated permissible values listed in Table 3 -3.
The model results show that velocity and shear increases (as compared to the 30Q2 low flow)
due to the proposed quarry dewatering discharge, but stay below the estimated maximum
permissible shear and velocity. Peak flow conditions of the 1 -year storm produce shear that is
higher than the estimated maximum permissible shear stress while velocity was below the
estimated maximum permissible velocity except at cross - section 50,380. The additional
proposed quarry dewatering discharge had a minimal effect on the 1 -year peak flow
hydraulics on Blounts Creek.
Model results for the reach of UT2 are shown in Table 1 -5.
i♦ Kimley -Horn 9 of 14
i•n and Associates, Inc,
Low Flow
1 -year 24 -hour Storm
River
Station
Shear (1b /ft2)
Velocity (fps)
Shear (lb/ft)
Velocity (fps)
Ex
Fu
A
Ex
Fu
0
Ex
Fu
0
Ex
Fu
A
55,513
0.07
0.11
0.04
0.71
1.04
0.33
0.31
0.32
0.01
2.11
2.14
0.03
54,460
0.06
0.14
0.08
0.66
1.17
0.44
0.43
0:44
0.01
2.42
2.43
0.01
53,848
0.06
0.12
0.04
0.64
1.03
0.39
0.19
0.19
0.00
1.64
1.66
0.02
52,597
0.03
0.07
0.04
0.47
0.81
0.34
0.00
0.89
0.91
0.02
0.06
0.06
51,462
0.01
0.03
0.02
0.29
0.57
0.28
0.00
2.10
2.11
0.01
0.28 0.28
50,380
0.05
0.10
0.05
0.62
0.96
0.34
0.53
0.53
0.00
2.86
2.87
0.01
49,1742
0.03
0.05
0.02
0.52
0.65
0.13
0.18
0.18
0.00
1.63
1.63
0.00
1 Feet above Blounts Bay
Z Last cross - section on Weyerhauser property, approximately 7250 feet upstream from Tripp Road
Note: Ex = Existing Conditions; Fu = Future Conditions, d = Difference between future and existing conditions. Highlighted
cells exceed the estimated permissible values listed in Table 3 -3.
The model results show that velocity and shear increases (as compared to the 30Q2 low flow)
due to the proposed quarry dewatering discharge, but stay below the estimated maximum
permissible shear and velocity. Peak flow conditions of the 1 -year storm produce shear that is
higher than the estimated maximum permissible shear stress while velocity was below the
estimated maximum permissible velocity except at cross - section 50,380. The additional
proposed quarry dewatering discharge had a minimal effect on the 1 -year peak flow
hydraulics on Blounts Creek.
Model results for the reach of UT2 are shown in Table 1 -5.
i♦ Kimley -Horn 9 of 14
i•n and Associates, Inc,

Table 1 -5: UT -2 Model Results Comparison
' Feet above confluence of UT -2 with Blounts Creek
* Upper portion of UT2 that is in man -made collector ditches within the MMM proposed mine site, and not considered stream
or modified natural channel
** Station 6 020 Origin of UT2 considered to be modified (ditched) natural channel by the USA CE
* ** Station 4,370 Origin of UT2 considered to be a regulated stream subject to the Tar - Pamlico Riparian Buffer Rules
Note: Ex = Existing Conditions; Fu = Future Conditions, A = Difference between future and existing conditions. Highlighted
cells exceed the estimated permissible values listed in Table 3 -3.
The model results for UT -2 show that velocity and shear increases (as compared to the 30Q2
lowflow) due to the proposed quarry dewatering discharge, but stay below the estimated
maximum permissible shear and velocity. Peak flow conditions of the 1 -year storm produce
shear and velocity that is higher than the estimated maximum permissible shear stress and
velocity. The additional proposed quarry dewatering discharge had a minimal effect on the
1 -year peak flow shear but increases velocity in the upper reach ditch UT -2.
There are two cross sections where the model predicts that future conditions will exceed the
estimated critical velocity or shear stress, and the existing conditions do not exceed the
thresholds. These cross sections occur at stations 3,750 and 3,920, which are immediately
downstream and upstream, respectively, of an existing culvert under Blounts Creek Road. It
is important to observe the predicted increase in shear stress at station 3,920 is similar to the
predicted increases at the other stations. The same is true of the predicted change in velocity
at station 3,750. For both cross sections, the change represents an increase of approximately
13% for both shear stress and velocity. It is important to note, that both the existing and
future conditions shear stress predicted at 3,920 and existing and future conditions velocity
[:® Klmley -Horn 10 of 14
®n and Associates, Ina
Low Flow
1 -yr 24 -hr Storm
River
Station `
Shear (lb /ft')
Velocity (fps)
Shear (lb/ft)
Velocity (fps)
Far
Fu
A
Ex
Fu
A
Ex
Fu
A
Ex
Fu
A
8,085*
0.04
0.14
0.10
0.86
2.39
1.53
0.36
0.39
0.03
4.54
4.81
0.27
7,515*
0.01
0.14
0.13
0.43
2.38
1.95
0.33
0.36
0.03
4.37
4.64
0.27
6,020 **
0.05
0.14
0.09
0.99
2.37
1.38
0.44
0.48
0.04
4.96
5.30
0.34
4,370 * **
0.01
0.09
0.08
0.38
1.82
1.44
0.18
0.20
0.02
3.04
3.25
0.21
3,920
0.12
0.10
-0.02
1.40
1.93
0.53
7.14
0.16
0.02
2.71
2.94
0.23
3,820
0.01
0.08
0.07
0.51
1.72
1.21
0.12
0.14
0.02
2.56
2.80
0.24
3,750
0.00
0.04
0.04
0.17
1.24
1.07
0.11
0.14
0.03
2.31
2.67
0.36
3,263
0.02
0.11
0.09
0.28
1.00
0.72
0.22
0.23
0.01
1.75
1.80
0.05
1,420
0.02
0.08
0.06
0.29
0.81
0.52
0.49
0.49
0.00
0.01
2.74 2.75
' Feet above confluence of UT -2 with Blounts Creek
* Upper portion of UT2 that is in man -made collector ditches within the MMM proposed mine site, and not considered stream
or modified natural channel
** Station 6 020 Origin of UT2 considered to be modified (ditched) natural channel by the USA CE
* ** Station 4,370 Origin of UT2 considered to be a regulated stream subject to the Tar - Pamlico Riparian Buffer Rules
Note: Ex = Existing Conditions; Fu = Future Conditions, A = Difference between future and existing conditions. Highlighted
cells exceed the estimated permissible values listed in Table 3 -3.
The model results for UT -2 show that velocity and shear increases (as compared to the 30Q2
lowflow) due to the proposed quarry dewatering discharge, but stay below the estimated
maximum permissible shear and velocity. Peak flow conditions of the 1 -year storm produce
shear and velocity that is higher than the estimated maximum permissible shear stress and
velocity. The additional proposed quarry dewatering discharge had a minimal effect on the
1 -year peak flow shear but increases velocity in the upper reach ditch UT -2.
There are two cross sections where the model predicts that future conditions will exceed the
estimated critical velocity or shear stress, and the existing conditions do not exceed the
thresholds. These cross sections occur at stations 3,750 and 3,920, which are immediately
downstream and upstream, respectively, of an existing culvert under Blounts Creek Road. It
is important to observe the predicted increase in shear stress at station 3,920 is similar to the
predicted increases at the other stations. The same is true of the predicted change in velocity
at station 3,750. For both cross sections, the change represents an increase of approximately
13% for both shear stress and velocity. It is important to note, that both the existing and
future conditions shear stress predicted at 3,920 and existing and future conditions velocity
[:® Klmley -Horn 10 of 14
®n and Associates, Ina

Nf
rd
Legend
0 Dewatering Discharge Point
0 Confluence of Blounts Creek and Herrings Run
0 The Cotton Patch Subdivision
r,,,l Project Boundary
Velocity (fps)
W+ E
_
Prepared By:
EM" Kimley
and Associates, Inc.
Velocity: I -yr Storm
Vanceboro
Stability Analysis
A�
Prepared For:
Martin Marietta Materials
_
Prepared By:
EM" Kimley
and Associates, Inc.
Velocity: I -yr Storm

at 3,750 are within 7% of the estimated permissible threshold values. It is KHA's opinion
that this change is small enough that it would be masked by natural variability predicted
within the rainfall and runoff patterns described in the paragraph below, despite the fact that
the future conditions value exceeds the estimated permissible value and the existing
conditions value does not. As such, any changes to the channel geometry are expected to be
minimal, and should not result in excessive erosion. It is recommended that MMM visually
monitor the channel yearly (using photograph points) as discharge rates increase to assess
changes, if any, to channel stability.
The 1 -year rainfall depth is 3.19 inches and the peak flow rate for the drainage area at river
station 55,513 is 230 cfs. The corresponding rainfall depth for the same drainage area for
221 cfs (1 -year peak flow rate minus proposed quarry dewatering discharge) is approximately
3.14 inches. The 90% confidence interval for the 1 -year 24 -hour storm is 2.92 -3.56 inches.
Since the future adjusted 1 -year rainfall depth lies well within that confidence interval, the
future dewatering discharge is not anticipated to increase the frequency of storm discharges.
1.4 Conclusion
It is expected that the increase in discharge from the proposed quarry will result in some adjustments
in the base -flow geometry of the stream. The modeling results suggest that such adjustments should
not result in excessive erosion of the stream since the estimated maximum permissible shear stresses
and velocities should not be exceeded in low flow conditions. Additionally, storm events are assumed
to have the most influence on channel geometry since they result in larger velocities and shear stress
as the water column surcharges above the channel. Typically, NCDWQ considers the 1 -year 24 -hour
discharge to be related to channel stability for its various stormwater programs. The above results
show only minor changes during the peak 1 -year 24 -hour storm event when comparing the existing
conditions to the proposed quarry dewatering discharge. Based on this analysis, it is not anticipated
that the maximum dewatering discharge would result in major stream channel profile or geometry
changes.
fi Kimley -Horn 11 of 14
�� and Associates, Inc.

References
Chow, Ven Te (1959). Open- Channel Hydraulics. Caldwell, NJ: The Blackburn Press.
Fry, Brian (2002). Conservative Mixing of Stable Isotopes Across Estuarine Salinity Gradients: A Conceptual
Framework for Monitoring Watershed Influences on Downstream Fisheries Production. Estuaries and
Coasts, 25, 264 -271.
Stenstrom, Petter (2004). Hydraulics and mixing in the Hudson River estuary: A numerical model study of
tidal variations during neap tide conditions. Journal of Geophysical Research, 109(C04019), 1 -12.
Snoeyink, Vernon L., & Jenkins, David (1980). Water Chemistry. New York, NY: John Wiley & Sons.
UNESCO (1981). Background Papers and Supporting Data on the Practical Salinity Scale 1978 (UNESCO
Technical Papers in Marine Science 37). Place de Fontenoy, Paris: United Nations Educational, Scientific
and Cultural Organization.
U.S. Geological Survey (1993). Low -Flow Characteristics of Streams in North Carolina (United States
Geological Survey Water - Supply Paper 2403). Denver, CO: US Government Printing Office.
U
C:j Ki—/mley -Horn 12 of 14
i► `� and Associates, Inc.

Addendum
Additional Velocity Analysis and Response to Comments
Provided by NC Division of Marine Fisheries and NC Wildlife Resource Commission
on September 21, 2012
Date: October 10, 2012
Project: Vanceboro Site
Martin Marietta Materials
Craven and Beaufort Counties, North Carolina
Subject: Response to Comments by NC Division of Marine Fisheries and NC Wildlife Resource
Commission
Kimley -Horn and Associates, Inc. (KHA), Martin Marietta Materials (MMM), Coastal Zone Resources
(CZR) met with NC Division of Marine Fisheries ( NCDMF) and NC Wildlife Resources Commission
( NCWRC) on September 21, 2012 held in the NCDENR Washington Regional Office to discuss their
comments on the KHA Technical Memorandum "Flooding, and Water Quality Analyses", dated September 6,
2012. This addendum has been prepared to provide additional information /discussion in regard to the
general comments provided at the meeting.
■ Comment —The NCDMF and NCWRC expressed concern that the proposed discharge would
increase velocity and potentially affect spawning habitat suitability within Blounts Creek. In
particular, NCWRC commented that velocities shown for the 1 -Year, 24 -Hour storm event of 2.5
fps was high and may impact the in- stream spawning habitat.
Kimley -Horn Response — Hydrologic and hydraulic modeling was conducted in the upper reaches of
Blounts Creek and an Unnamed Tributary to Blounts Creek (UT -2) within the Weyerhaeuser
property to assess the potential change from additional quarry discharge on base flow and for a
moderately large storm event (1 year, 24 hour storm or 3.19 inch rainfall).
The results of the base flow modeling have been shown in Table 1 -4 and Table 1 -5 of the "Flood and
Stability Analysis" technical memorandum, dated October 10, 2012, for the upper portions of
Blounts Creek and UT -2, respectively (also shown in Figure 1 attached to this addendum). Under
base flow conditions, the highest predicted average velocity in the upper portion of Blounts Creek is
1.17 fps with the addition of the quarry discharge. This occurs at the uppermost portion of the
watershed and predicted velocities decrease as flow travels downstream. This predicted base flow
velocity is below the 2.5 fps that was discussed as a concern, and the greatest velocity of the area (1.0
to 1.2 fps) occurs only in the uppermost portion of the watershed. The uppermost portion of UT -2
is upstream of station 3,750, that is located at the culvert crossing under Blounts Creek Road, to the
origin of the jurisdictional stream channel at station 6,020, which is also the location of the proposed
G ® Kimley -Horn 13 of 14
®� and Associates, Inc

NPDES Outfall 002. The relative change in velocities (with the addition of the quarry discharge) in
this area shows a relatively large change in velocity between existing and proposed maximum
discharge conditions. This is, in part, due to the very small existing conditions discharge the stream
currently experiences in low flow conditions. The existing stream has also been significantly
channelized upstream of the culvert. KHA has observed the UT to have no flow on several occasions
and, as such, is considered as intermittent in the upper portions. In any event, the resulting velocities
with the maximum quarry discharge remain below 2 fps, and generally decrease downstream.
Modeling was also conducted to compare the velocities that would be experienced at various
locations along Blounts Creek as the result of a 1 -year, 24 -hour rain event (or a storm that has a 50%
chance of occurring in any year). The velocity results are summarized in Table 1 -4 of the "Flood and
Stability Analysis" technical memorandum, dated October 10, 2012, and are shown in Figure 2
attached to this addendum. The model results show that there were two locations within the upper
portion of Blounts Creek that experienced velocities close to 2.5 fps under existing conditions for the
larger storm event. The addition of the quarry dewatering discharge would result in an increase of
only 0.01 fps in both situations which should not be noticeable.
Table 1 -5 shows that 2.5 fps will be exceeded in both the existing conditions and proposed condition
with quarry discharge added at all except one cross section for the same sized storm events in UT -2.
In summary, the analysis of the 1 -year, 24 -hour storm event shows that existing velocities within
Blounts Creek and UT -2 currently exceed 2.5 fps in the upper portion of the watershed, and the
degree of change with the additional quarry discharge varies from minimal (i.e. 0.36 fps) to negligible
(i.e. 0.01 fps).
O Comment Increased erosion from the increase in quarry discharge may result in increased turbidly.
Kimley -Horn Response— The stability analysis conducted shows that even if the full 18 cubic feet
per second (cfs) of discharge were instantly distributed to Outfalls 1 and 2, the velocities and shear
stresses experienced throughout the streams would not be increased to the point that excessive erosion
would occur, thereby increasing turbidity downstream. Additionally, the anticipated discharge of 18
cfs would likely gradually increase over a period of years, further allowing any change in channel
geometry to reach equilibrium gradually without becoming unstable. Therefore, significant bank
failure and stream bed erosion that could cause a significant amount of turbidity or sedimentation is
not anticipated.
C � Kimley -Horn 14 of 14
and Associates, Ina

Attachment
Model Results Comparison Tables

Vanceboro Future Pit Discharge Stability Analysis
Shear (Ib /ft2)
Velocity (fps)
RIVER
30QZ
1 -yr Max WSEL
30QZ
1 -yr Max WSEL
STATION
Existing
Future
Change
Existing
Future
Change
Existing
Future
Change
Existing
Future
Change
71300
000
004
004
000
003
003
004
159
155
003
134
131
69286
000
030
030
001
009
008
002
376
374
046
206
160
69176
000
002
002
000
000
000
000
090
090
009
048
039
66451
001
008
007
003
008
005
047
191
144
080
175
09S
66402
001
007 1
006
002 1
007
005
033 1
184
151
070-1
1 68
098
66353
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
66304
001
003
002
001
002
001
035
121
086
053
102
049
66239
000
003
003
001
002
001
022
116
094
043
096
053
63140
000
005
005
000
003
003
003
154
151
015
106
091
60629
001
006
005
002
004
002
040
167
127
064
135
071
60579
000
005
005
001
004
003
024
160
136
051
126
075
60539
DITCH CULVERT
DITCHCULVERT
DITCH CULVERT
DITCH CULVERT
60500
001
017
016
006
014
0 08
043
264
221
115
216
101
60465
006
017
011
017
015
-002
107
261
154
258
224
-034
60067
003
006
003
003
006
003
089
168
079
094
145
051
60025
002
006
004
002
005
003
079
161
082
080
138
058
59989
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
59952
003
010
007
003
007
004
087
203
116
092
162
070
59849
002
Oil
009
003
008
005
086
212
126
089
169
080
57421
003
007
004
003
006
003
097
180
083
099
147
048
57382
002
007
005
003
005
002
084
173
089
086
137
051
57351
NPDES DISCHARGE POINT
NPDES DISCHARGE POINT
NPDES DISCHARGE POINT
NPDES DISCHARGE POINT
57319
006
022
016
001
010
009
121
284
163
051
185
134
57222
009
017
008
000
005
005
144
258
114
028
134
106
56714
004
017
013
000
000
000
056
134
078
003
018
015
55513
007
010
003
031
032
001
071
104
033
211
214
003
54460
006
021
015
043
044
001
066
149
083
242
243
001
53848
006
014
008
019
019
000
064
119
055
164
166
002
52597
003
009
006
006
006
1 000
047
097
050
089
091
002
51462
001
005
004
028
028
000
029
076
047
-210
211
001
50380
005
014
009
053
053
000
062
118
056
286
287
001
49174
003
005
002
018
018
000
052
075
023
163
163
000
44901
001
0 06
005
008
008
000
030
083
053
1 15
116
001
44851
000
001
001
070
071
001
012
038
026
332
334
002
44846
RAILROAD
RAILROAD
RAILROAD
RAILROAD
44842
000
001
001
072
073
001
013
038
025
338
340
002
44742
003
009
006
025
025
000
054
096
042
204
'2 04
000
42007
001
003
002
031
031
000
031
055
024
224
224
000
41972
000
001
001
018
018
000
009
027
018
172
173
001
41942
TRIPP RD
TRIPP RD
TRIPP RD
TRIPP RD
41912
000
001
001
0 19
0 19
000
009
027
018
176
176
000
41827
002
004
0 02
036
1 036
000
036
058
022
240
240
000
40111
005
010
005
019
019
000
063
095
032
177
177
000
36680
000
003
003
020
020
000
009
054
045
188
188
000
34964
000
000
000
033
033
000
000
021
021
233
234
001
34939
000
000
000
028
029
000
001
017
016
216
217
001
34909
NC -33
NC -33
NC -33
NC -33
34879
000
000
000
029
029
000
001
017
016
220
221
001
34800
000
000
000
036
037
001
001
021
020
245
246
001
28600'
000
000
000
004
004
000
-002
001
003
085
086
001
25000
000
000
000
002
002
000
-001
000
001
062
063
001
15900"
000
000
000
001
001
000
-002
-001
001
034
035
001
7000
000
000
000
000
000
0 00
-003
-002
001
000
000
000

Vanceboro Future Pit Discharge Flooding Evaluation
RIVER
MAXIMUM WSEL VELOCITY (fps)
STATION
1 -YR (TIDES')
5 -YR (NO TIDE)
25 -YR (FRICTION SLOPE 3)
100-YR (SURGE°)
EXISTING
FUTURE
CHANGE
EXISTING
FUTURE
CHANGE
EXISTING
FUTURE
CHANGE
EXISTING
FUTURE
CHANGE
71300
0.32
1.59
127
050
1.59
109
0.50
159
1.09
0.32
1.59
1.27
69286
0.22
3.49
3.27
0.38
3.43
3.05
038
3.45
3.07
0.22
3.42
3.20
69176
0.05
085
0.80
008
0.83
075
0.08
084
0.76
0.05
083
0.78
66451
0.80
191
1.11
092
1.91
099
0.92
1.91
0.99
0.80
191
1.11
66402
0.70
1.84
1.14
0.84
1 184
1.00
084
1.84
1.00
0.70
1.84
1.14
66353
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
66304
0.53
121
0.68
057
1.21
0.64
0.57
121
0.64
0.53
121
0.68
66239
0.39
1.16
0.77
0.48
1.16
0.68
0.48
1.16
0.68
0.39
1.16
0.77
63140
012
154
1.42
0.21
154
133
0.21
1.54
133
012
1.54
142
60629
064
1.67
103
0.74
167
0.93
074
1.67
0.93
064
1.67
1.03
60579
051
1.60
1.09
0.62
160
0.98
0.62
160
0.98
0.51
160
1.09
60539
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
60500
1.15
264
1.49
124
2.64
1.40
1.24
2.64
140
1.15
2.61
1.46
60465
2.58
2.61
0.03
112
2.61
1.49
1.02
260
1.58
2.58
256
-0.02
60067
081
1.68
087
0.94
168
074
094
1.68
0.74
0.43
1.62
1.19
60025
0.69
1.61
092
0.83
161
0.78
0.84
1.61
0.77
0.36
1.56
1.20
59989
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
59952
0.78
2.03
1.25
0.93
2.03
1.10
093
2.03
1.10
0.33
189
1.56
59849
0.76
212
1.36
091
2.12
121
0.91
2.11
1.20
029
1.91
1.62
57421
089
1.80
0.91
0.25
180
1.55
0.11
1.31
1.20
0.03
090
087
57382
076
1.73
0.97
0.22
1.73
1.51
0.10
127
1.17
0.03
089
086
57351
NPDES DISCHARGE POINT
NPDES DISCHARGE POINT
NPDES DISCHARGE POINT
NPDES DISCHARGE POINT
57319
0.24
2.52
2.28
0.13
1.51
1.38
0.06
0.84
078
0.02
0.52
0.50
57222
0.13
2.08
1.95
0.10
1.22
1.12
0.06
073
0.67
0.02
0.48
0.46
56714
0.01
0.33
0.32
001
0.15
014
0.01
0.09
0.08
0.00
007
0.07
55513
2.11
2.17
0.06
2.74
2.77
0.03
3.28
3.30
0.02
3.69
3.71
0.02
54460
2.42
245
0.03
2.68
2.71
0.03
288
2.90
0.02
3.02
3.04
002
53848
1.64
1.68
004
1.87
190
0.03
2.14•
216
0.02
2.24
2.26
0.02
52597
089
0.94
005
0.96
0.99
0.03
1.06
1.08
002
1.16
1.17
0.01
51462
2.10
2.13
0.03
2.74
276
0.02
3.41
3.42
001
3.91
3.92
0.01
50380
2.86
2.89
003
3.33
3.34
0.01
3.54
355
0.01
360
3.61
0.01
49174
1.63
1.64
001
1.77
177
0.00
1.82
182
0.00
185
1.85
0.00
44901
1.15
1.17
0.02
1.27
1.28
001
1.40
1.41
001
1.51
1.52
001
44851
332
3.37
0.05
500
5.03
003
6.41
6.42
0.01
7.35
7.37
0.02
44846
RAILROAD
RAILROAD
RAILROAD
RAILROAD
44842
3.38
3.43
0.05
5.17
5.20
0.03
6.72
6.74
002
7.76
777
001
44742
2.04
2.05
001
2.38
238
0.00
2.67
2.68
001
2.87
2.87
000
42007
224
2.25
0.01
250
2.50
000
2.80
2.80
0.00
3.00
3.00
0.00
41972
172
1.73
0.01
2 11
2.11
000
245
2.45
0.00
2.68
2.68
0.00
41942
TRIPP RD
TRIPP RD
TRIPP RD
TRIPP RD
41912
176
177
0.01
2.21
221
00.0
255
256
001
284
2.85
001
41827
2.40
2.41
001
2.71
2.72
001
2.97
2.98
0.01 1
3.23
3.24
0.01
40111
1.77
1.78
001
2.13
214
0.01
256
256
000
294
295
001
36680
188
1.88
0.00
2.18
2.19
001
272
272
0.00
317
317
000
34964
2.33
235
0.02
2.97
2.98
001
310
310
0.00
250
250
000
34939
2.16
2.19
0.03
3.23
3.25 1
002
4.18
419
0.01
434
427
-007
34909
NC -33
NC -33
NC -33
NC -33
34879
2.20
2.22
002
3.31
3.34
0.03
4.43
4.44
0.01
4.35 1
4.37
0.02
34800
2.45
2.47
0.02
3.11
312
0.01
3.29
3.30
0.01
2.68
2.69
0.01
28600*
0.85
087
0.02
1.60
1.62
0.02
208
2.09
001
0.58
060
0.02
25000
0.62
0.63
001
1.32
133
0.01
-84
1.84
0.00
-0.29
-0.26
0.03
15900 **
0.34
0.35
0.01
0.79
0.80
0.01
1.10
1.11
0.01
-0.68
-0.67
0.01
7000
0.00
0 00'
0.00
0.00
0 00
0.00
0.90
0.90
0.00
-0.57
-0.57
0.00
' Estimated daily tide with amplitude of Vat Blounts Bay
Z No change in downstream water surface elevation
3 Downstream friction slope of 0.01%
4 Theoretical 100-yr surge stage hydrograph based on FEMA FIS elevations and storm data and timed 12 hours after peak precipitation
* Confluence of Blount's Creek with Herrings Run
** Approximate location of the Cotton Patch

Vanceboro Future Pit Discharge Flooding Evaluation
RIVER
MAXIMUM WATER SURFACE ELEVATION (NAVD 88)
STATION
1 -YR (TIDES`)
5 -YR (NO TIDE)
25 -YR (FRICTION SLOPES)
100-YR (SURGE°)
EXISTING
FUTURE I
CHANGE
EXISTING
FUTURE
CHANGE
EXISTING I
FUTURE
CHANGE
EXISTING
FUTURE
CHANGE
71300
34.52
38.49
397
3472
3849
3.77
34.72
38.49
3.77
34.52
38.49
3.97
69286
34.41
35.69
1.28
3452
3567
1.15
34.52
35.68
1.16
3441
35.68
1.27
69176
34.41
35.67
1.26
34.51
3565
114
3451
35.65
1.14
34.41
35.65
1.24
66451
32.39
34.53
2.14
32.50
3453
2.03
32.50
34.53
203
3239
34.53
2.14
66402
32.33
34.51
2.18
3244
34.51
2.07
32.44
34S1 1
207
32.33
34.51
218
66353
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
66304
3199
34.24
2.25
32.14
34 24
2 10
32.14
3424
210
31.99
3424
2.25
66239
31.97
34.23
2.26
32.12
34.23
2.11
3212
34.23
2.11
3197
34.23
2.26
63140
31.57
3327
170
31.67
3327
160
31.67
33.27
1.60
3157
33.27
1.70
60629
30.28
32.10
182
3039
32.10
1.71
30.39
32.10
1.71
3028
3210
1.82
60579
30.25
3208
1.83
3036
32.08
1.72
3036
3208
1.72
3025
32.08
183
60539
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
60500
3000
31.12
112
3008
31.12 1
1.04
3008
3112
1.04
30.00
31.14
1.14
60465
2981
31.04
123
29.92
3104
1.12
29.92
3104
112
29.81
3106
1.25
60067
28.54
30 47 1
1.93
28.75
3047
172
28.74
30.47
173
28.60
3053
193
60025
2851
30.44
1.93
2871
30.44
1.73
2871
3044
1.73
28.59
3051
192
59989
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
DITCH CULVERT
59952
2840
3001
1.61
28.61
3001
140
2861
3002
141
28.57
3012
1.55
59849
2832
29.85
1.53
2852
29.85
1.33
2852
29.86
1.34
28S6
30.01
1.45
57421
2547
27.03
1.56
2625
27.03
0.78
2743
27.62
0.19
2847
28.58
0.11
57382
25.42
2701
159
26.25
27.01
0.76
27.43
27.61
0.18
28.47
28.58
0.11
57351
NPDES DISCHARGE POINT
NPDES DISCHARGE POINT
NPDES DISCHARGE POINT
NPDES DISCHARGE POINT
57319
2503
25.79
0.76
2625
26.46
0.21
27.43
27.52
0.09
2847
1 28.52
0.05
57222
25.03
2560
057
26.25
2642
0.17
2743
27.51
0.08
2847
28.51
0.04
56714
25.03
2518
0.15
26.25
2633
008
27.43
2749
0.06
28.47
28.51
0.04
55513
2401
24.10
0.09
2504
25.11
0.07
26.14
26.18
004
27.13
27.17
0.04
54460
21.75
2183
0.08
2281
22.87
0.06
2403
24.08
0.05
25.13
25.17
004
53848
2062
2072
0.10
2186
21.92
0.06
23.23
23.27
0.04
24.44
24.48
0.04
52597
19.81
1989
008
2123
21.27
0.04
2266
22.69
0.03
2397
24.00
0.03
51462
19.07
1912
0.05
20.38
2042
0 04
2168
21.71
0.03
2293
22.96
0.03
50380
17.33
17.38
0.05
1856
18.60
0.04
19.90
19.93
003
21.30
2133
003
49174
15.56
1562
006
16.96
1700
0.04
18.59
18.62
0.03
2025
2028
003
44901
1341
1345
0.04
15.25
15.28
003
17.27
17.30
0.03
1918
19.20
0.02
44851
13.26
1331
0.05
1498
15.02
004
16.90
1693
003
18.74
18.76
0.02
44846
RAILROAD
RAILROAD
RAILROAD
RAILROAD
44842
13.18
1322
004
1479
1483
004
1657
1660
003
1832
18.35
0.03
44742
13.06
13.10
0.04
1464
1467
0 03
1641
1644
003
18.19
18.22
0.03
42007
1040
10.45
0.05
12.35
12.40
005
14.36
14.39
0.03
1639
1641
002
41972
10.38
1043
0.05
12.33
12.37
004
14.34
14.37
0.03
1637
16.39
0.02
41942
TRIPP RD
TRIPP RD
TRIPP RD
TRIPP RD
41912
1030
10.35
005
1213
1217
0.04
1411
1413
0.02
1594
15.96
0.02
41827
10.21
10.26
0.05
12.06
12.10
004
1404
1407
003
15.88
1590
002
40111
852
8.57
0 05
10.66
1070
004
1279
12.82
0.03
14.68
1471
003
36680
634
6.41
0 07
879
883
004
10.78
1080
0.02
1253
12.55
0.02
34964
4.88
4.94
0 06
728
732
0.04
946
9.48
0.02
11.59
11.61
002
34939
4.86
4.92
0.06
720
7.24
004
932
935
003
1145
11.47
0.02
34909
NC -33
NC -33
NC -33
NC -33
34879
4.76
482
0 06
701
704
0.03
8.93
896
0.03
10.87
10.89
002
34800
4.67
472
0 05
693
697
004
889
8.91
002
10.86
1088
002
28600*
0.96
0.97
0 01
2.24
226
0.02
471
4.73
0.02
930
931
001
25000
0.76
077
0.01
1.60
1.61
0.01
3.84
3.86
0.02
9.13
9.14
001
15900 **
0.57
0.57
0.00
0.82
0.83
0.01
2.68
2.69
0.01
8.95
8.95
0.00
7000
0.50
0 50
0.00
050
0.50
000
187
1.87
0.00
9.20
920
000
' Estimated daily tide with amplitude of 1' at Blounts Bay
2 No change in downstream water surface elevation
S Downstream friction slope of 0 01%
"Theoretical 100-yr surge stage hydrograph based on FEMA FIS elevations and storm data and timed 12 hours after peak precipitation
* Confluence of Blount's Creek with Herrings Run
** Approximate location of the Cotton Patch