20070707 Ver 1_More Info Received_20070801

Rug 01 07 10:05a Land Management Group Inc 9104520060 p.1
ASLMG
LAND MANAGEMENT GROUP wc.
Environmental Consultants
FACSIMILE TRANSMITTAL SHEET
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Company: ff
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2-5Z •
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NoteslComments:
www.lmgroup.net - info @lmgroup.net - Phone: [phone] - Fax: [phone]
3805 Wrightsville Ave., Suite 15, Wilmington, NC 28403 - P.O. Box 2522, Wilmington, NC
28402

Aug 01 07 10:05a Land Management Group Inc 9104520060 p.3
Shown sampmiy pviiuz� diC <ippiu7ui11dlc.
Map Source: 1998 NAPP aerial photography
Lee Cox
Pecan Grove Marina
Pamlico County, NC
02 -05 -232
SITE
Land Management Group, Inc.
Environmental Consultants
Wilmington, N.C.
September, 2005
SCALE 1" = 400'
Figure 1
Aerial Photograph

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•
�7
DISSOLVED OXYGEN MODELING
Pecan Grove Marina
Neuse River
Pamlico County, North Carolina
Prepared for:
Cox Family Properties, LLC.
Oriental, NC
And as requested for:
NC Department of Environment and Natural Resources
Division of Water Quality
Wilmington, NC
Prepared by:
Land Management Group, Inc.
Environmental Consultants
Wilmington, NC
June 2007

DISSOLVED OXYGEN MODELING
PECAN GROVE MARINA
NEUSE RIVER
PAMLICO COUNTY, NORTH CAROLINA
Site Description
JUNE 2007
A.
Existing Conditions
Pecan Grove marina is located along the Neuse River near the
mouth of Greens Creek in Oriental, NC (Figures 1 and 2). The
existing marina includes an upland basin of approximately 3.4
acres and a roughly 1.2 acre entrance channel (Figure 2). Water
depths within the basin and entrance channel are approximately 8 ft
normal low water (NLW). An open water maintained channel
extends approximately 1600 ft beyond the Pecan Grove marina
entrance channel and leads to deeper waters of the Neuse River.
Maintenance dredging has historically been performed as
necessary to maintain 8 ft of water depth within the access channel.
B.
Proposed Project and Purpose
A NC CAMA Major permit application currently requests to expand
the existing basin. The roughly 146,697 sq.ft. (3.4 acres) basin
would be enlarged to roughly 306,697 sq.ft. (7.1 acres). Expansion
would occur on the currently bulkheaded south - western edge into
adjacent upland.
C.
Neuse River
Waters of the Neuse River adjacent to the property are classified as
_-SA;�HQW, NSW by the North Carolina Division of Water Quality
V
(DWQ). SA waters, by definition, include surface waters utilized for
shellfishing or marketing purposes and primary recreation, including
frequent swimming. The SA designation also includes tidal salt
waters protected for secondary recreation such as fishing, boating
and other activities involving minimal skin contact. These waters
are suitable for aquatic life propagation and survival and wildlife.
Waters of the Neuse River in the vicinity of Pecan Grove are
Ac�
`
currently closed to shellfishing.
The HQW classification is intended to protect waters with quality
higher than state water quality standards. The NSW supplemental
classification indicates nutrient sensitive waters with water quality
Dissolved Oxygen Modeling
• Pecan Grove Marina, Neuse River, Pamlico County

0
problems associated with excessive plant growth resulting from
nutrient enrichment. Waters with a NSW designation require
limitations on excessive nutrient inputs.
Portions of the access channel are classified as primary nursery
area (PNA) (Figure 2). PNAs are those areas where food, cover,
bottom type, salinity, temperature and other factors exist allowing
for initial post - larval development of finfish and crustaceans.
Water levels within the lower Neuse River at the project site are
subject to minimal lunar tides. Tidal amplitudes in this vicinity are
largely wind driven and therefore highly variable. The average tidal
41 range was estimated to be 2.0 ft. However, given the orientation of
the marina basin, tidal amplitudes can be much higher, especially
during northeast winds.
II. Water Quality
W quality samplin cl was conducted at Pecan Grove during the months
of June, July and August 2005. esults of this sampling are summarized
tn-Tables -1 — 5. Vertical profiles of physical water parameters were
collected using a YSI 85 water quality probe. Parameters recorded
include, water temperature, dissolved oxygen (DO), specific conductivity
and salinity. A total of six (6) sites were sampled within the open water
access channel leading to the marina (Figure 2).
The lowest mean DO concentrations at Pecan Grove were observed on
June 17, 2005 (mean = 5.5 mg /L). Mean DO concentrations at Pecan
Grove were highest in July 2005 (mean = 7.8 mg /L). The mean ambient
DO concentration observed during June, July, and August 2005 sampling
across all sampling stations was 6.9 mg /L. Mesohaline salinities (range =
4.6 — 10.8 ppt) were recorded at Pecan Grove during all sampling events.
On -site atmospheric conditions were also recorded including, air
temperature, cloud condition, rainfall, wind direction and approximate wind
speed.
III. Dissolved Oxygen Modeling
A. Background
The Coastal Plain of North Carolina has been subject to steady
increases in residential, commercial, and industrial growth. As a
result, there have been increasing demands for water access to
provide recreational opportunities to both residential communities
and the public. In response to concerns regarding the water
Dissolved Oxygen Modeling 2
Pecan Grove Marina, Neuse River, Pamlico County

` rt
Lee Cox
Pecan Grove Marina
Pamlico County, NC
02 -05 -232
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Land Management Group, Inc
Environmental Consultants
Wilmington, N.C.
SCALE 1" = 400'
DO Sampling Locations
July 2007

Pecan Grove DO sampling
Subject: Pecan Grove DO sampling
From: "Laura Stasavich" <ltasavich @lmgroup.net>
Date: Thu, 2 Aug 2007 12:19:01 -0400
To: <roberto.scheller @ncmail.net>
Roberto,
As requested in our phone conversation yesterday, I am providing a DO sampling plan for Pecan
Grove Marina. The attached pdf shows the approximate location of proposed DO sampling stations.
DO was sampled on 7/27/2007, and will be sampled again on 8/3/2007 and 8/6/2007. A calibrated
YSI 85 water quality probe will be used to measure water temperature, salinity, conductivity, and DO.
At each sampling station, measurements will be taken just above the bottom, at a mid -point in the
water column, and just below the surface. If water depths at the sampling station are 2' or less, one
point in the middle of the water column will be sampled.
Please feel free to contact me at 910 - 452 -0001 or lstasavich(a,lmgroup.net if you would like to discuss
this plan. Thank you for your help.
Laura
Laura Stasavich
Land Management Group, Inc.
P.O. Box 2522
3805 Wrightsville Ave., Suite 15
Wilmington, NC 28402
910 - 452 -0001 (p)
910 - 452 -0060 (f)
1 stasavi ch(a�, lm group. net
1 of 2 8/2/2007 2:24 PM

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quality of marinas and subsequent affects on adjacent coastal
waters, the North Carolina Division of Water Quality (formerly
NCDEM) issued Report No. 90 -01 which documents the
environmental integrity of several marinas in coastal NC. Based
upon the findings of this report and a growing concern for
cumulative impacts associated with marina development, NC DWQ
requires all new marina projects and all proposed marina
expansions demonstrate dissolved oxygen concentrations will meet
or exceed a state standard of 5.0 mg /L.
In order to determine if the proposed basin expansion can be
expected to meet the 5.0 mg /L state standard, DO concentrations
were forecasted via computer modeling. The state - recommended
computer modeling program provided by NC Division of Water
Quality incorporates a number of environmental parameters and
marina features including, but not limited to; ambient DO
concentrations, saturation DO, sediment oxygen demand (SOD),
marina depth, and marina surface area.
f
It is noted that SOD rates and associated chemical reduction and
tc/
bacterial respiration are site specific and can be influenced by
sediment substrate, sediment organic content, and water
'
temperature. Low organic, sandy substances have been generally
shown to exhibit lower SOD concentrations, whereas, more
organic, silty sediments may be expected to have higher SOD
rates. As demonstrated in previous studies, the SOD parameter
has great influence on forecasted DO values. !n situ SOD tests),
.have not been conducted in the vicinity of the marina. Therefore,
modeling results in this report provide predicted DO concentrations
across a range of SOD values (1.5 902/M2 /day — 3.0 902/M2 /day)
B. DO Modeling for Pecan Grove
A two segment DO model was generated for the proposed basin. A
proposed basin size of 306,697 sq.ft. and an entrance channel of
50,400 sq.ft were used as area dimensions in the DO model. The
model generated results over a range of DO concentrations,
including the mean ambient concentrations recorded on site from
June 2005 through August 2005 (5.0 mg /L — 8.0 mg /L). Since, in
situ SOD studies have not been conducted in the vicinity of Pecan
Grove; the model results also incorporate a range of SOD values
representing a number of conditions (1.5 902/M2 /day — 3.0
902/M2 /day). The DO model used an average channel depth and
marina depth of 8.0 ft NLW. The calculated saturation DO was 7.7
mg /L. Boat activity was considered negligible (0 boat/hrs /day) and
a conservative reaeration coefficient of 0.3 /day was used. The tidal
amplitude in this vicinity of the Neuse River is often highly variable
Dissolved Oxygen Modeling 3
Pecan Grove Marina, Neuse River, Pamlico County

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due to wind generated currents. As previously stated, estimates of
tidal amplitude in this vicinity average 2.0 ft. Therefore, a DO
model were generated to reflect a tidal amplitude of 2.0 ft.
IV. Conclusions
Table 6 summarizes the results from the DO model given a tidal
amplitude of 2.0 ft. These matrices display the break point along
decreasing DO and increasing SOD concentrations in which
conditions result in a forecasted DO greater than the State standard
of 5.0 mg /L ven a tidal amplitude of 2 D ft e DO model
forecasts D concentrations will m�eeo exceed the State standard
of 5.0 mg /L over a wide range of SOD and DO scenarios, including
the mean ambient DO concentration from summer 2005 sampling
(6.9 mg /L). However, it should be noted that during periods when
sediment oxygen demand is high and ambient DO concentrations
are depressed, DO within the proposed basin has the potential to
drop below the State standard of 5.0 mg /L. Overall, computer
modeling results predict the DO standard of 5.0 mg /L will be met
with the proposed expansion, except during periods of extreme C
high SOD coupled with low ambient DO concentrations.
1 CV
L
Dissolved Oxygen Modeling
Pecan Grove Marina, Neuse River, Pamlico County
111

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Table 1. Water quality parameters, Pecan Grove Marina, June 2, 2005.
Location
Depth
Sampled
(ft)
Water
Temp.
(OC)
Dissolved
Oxygen
(mg /L)
Salinity
(ppt)
Specific
Conductivity
(µS)
Site 1
0.5
20.4
7.2
9.8
15,120
4.5
20.3
7.3
9.8
15,200
9.0
20.3
7.2
9.9
15,150
Site 2
0.5
20.4
7.2
9.6
14,960
3.0
20.4
7.2
9.7
15,040
6.0
20.2
6.7
10.3
15,950
Site 3
0.5
20.4
7.2
9.7
15,000
3.0
20.4
7.3
9.8
15,090
6.0
20.2
7.3
10.0
15,450
Site 4
0.5
20.3
7.3
9.9
15,220
2.5
20.3
7.1
10.1
15,430
5.0
20.2
6.9
10.4
15,960
Site 5
0.5
20.9
6.7
7.4
11,840
2.5
20.4
7.2
9.1
14,870
5.0
20.3
7.1
10.3
15,900
Site 6
0.5
20.8
6.6
7.7
12,250
1.5
20.5
6.9
9.1
14,250
3.0
20.4
6.6
9.3
15,000

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Table 2. Water quality parameters, Pecan Grove Marina, June 17, 2005.
Location Depth Water Dissolved Salinity Specific
Sampled Temp. Oxygen (ppt) Conductivity
(ft) ( °C) (mg/L) (µS)
Site 1 27.1 6.8 7.0 13,930
r3.0 26.6 5.3 8.0 14,280
6.0 26.3 3.8 8.5 14,980
Site 2 0.5 27.1 7.2 9,000
2.5 26.8 5.3 8,000
5.0 26.3 2.7 11,000
Site 3 0.5 27.2 7.2 8,430
2.5 27.0 6.3 14,000
5.0 26.4 2.8 20,000
Site 4 0.5 27.4 7.7 13,000
2.5 27.2 7.4 12,000
5.0 26.5 3.1 8,200
Site 5 0.5 27.4 5.4 11,000
2.0 27.3 5.3 19,000
4.0 27.0 5.3 16,000
Site 6 0.5 27.5 6.9 8,500
2.0 27.5 6.9 8,500
3.0 10,200
4.0 27. 2
�t 2
* Instrument error.
Q
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Table 3. Water quality parameters, Pecan Grove Marina, June 30, 2005.
Location
Depth
Sampled
(ft)
Water
Temp.
( -C)
Dissolved
Oxygen
(mg /L)
Salinity
(ppt)
Specific
Conductivity
(µS)
Site 1
0.5
28.3
9.3
3.8
7,510
3.3
27.1
7.8
6.6
12,000
6.5
26.8
6.7
7.2
7,510
Site 2
0.5
27.8
9.0
6.4
11,690
2.8
27.7
9.2
6.5
11,900
5.5
26.6
6.2
7.1
12,700
Site 3
0.5
28.0
8.1
5.3
11,980
2.8
27.8
8.3
6.5
12,120
5.5
26.6
6.0
6.7
12,250
Site 4
0.5
28.0
7.8
5.5
10,220
2.8
27.9
7.8
5.1
9,700
5.5
26.7
5.7
5.9
12,480
Site 5
0.5
29.7
6.8
4.6
9,140
2.8
28.4
6.8
4.8
9,160
5.5
26.7
5.6
5.0
9,270
Site 6
0.5
29.9
5.9
6.5
12,580
2.0
29.2
5.8
6.7
12,780
4.0
27.6
3.15
7.4
13,550

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Table 4. Water quality parameters, Pecan Grove Marina, July 14, 2005.
Location
Depth
Sampled
(ft)
Water
Temp.
( °C)
Dissolved
Oxygen
(mg /L)
Salinity
(ppt)
Specific
Conductivity
(µS)
Site 1
0.5
27.8
8.34
10.5
18,770
3.3
27.8
7.55
10.6
19,010
6.5
27.7
6.84
10.7
19,080
Site 2
0.5
27.8
8.53
10.4
18,700
2.5
27.8
8.17
10.5
18,790
5.0
27.8
8.53
10.6
18,820
Site 3
0.5
27.8
8.25
10.5
18,820
2.5
27.8
8.33
10.5
18,800
5.0
27.7
7.12
10.6
18,980
Site 4
0.5
27.7
8.54
10.5
18,790
2.5
27.7
8.22
10.5
18,880
5.0
27.6
8.54
10.5
18,881
Site 5
0.5
28
7.56
9.9
18,440
2.3
27.9
8.16
10.6
19,000
4.5
27.8
7.85
10.6
19,000
Site 6
0.5
28.2
7.04
10.6
18,940
3.8
27.9
6.63
10.7
19,110
7.5
27.6
5.33
10.8
19,190

LM
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Table 5. Water quality parameters, Pecan Grove Marina, August 8, 2005
Location
Depth
Sampled
(ft)
Water
Temp.
( °C)
Dissolved
Oxygen
(mg/L)
Salinity
(ppt)
Specific
Conductivity
(PS)
Site 1
0.5
29.2
7.40
9.3
17,090
2.5
29.2
6.28
9.4
17,390
5.0
29.2
5.20
9.4
17,420
Site 2
0.5
28.8
8.55
8.7
16,070
2.0
28.8
8.57
8.7
16,450
4.0
29.1
6.17
8.9
17,260
Site 3
0.5
28.7
8.54
8.7
16,030
2.3
28.8
8.16
8.8
16,250
4.5
29.2
6.01
9.3
17,340
Site 4
0.5
28.7
8.74
8.6
15,960
2.3
28.7
8.45
8.7
15,990
4.5
28.4
5.67
9.3
16,060
Site 5
0.5
28.7
7.01
8.8
16,200
1.8
28.7
7.33
8.7
16,120
3.5
28.5
5.85
8.7
16,180
Site 6
0.5
28.9
6.65
8.7
16,200
2.5
28.4
5.80
8.8
16,140

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Table 6. DO Model Matrix, Pecan Grove Marina (tidal amplitude = 2.0 ft).
Pecan Grove Marina - Existing Entrance Channel
DISSOLVED
OXYGEN
(mg /L)
SEDIMENT OXYGEN DEMAND (g 02/M2 /day)
1.5
2.0
2.5
3.0
8.0
7.35
7.16
6.98
6.79
7.5
7.00
6.80
6.61
6.42
7.0
6.60
6.43
6.25
6.06
6.9
Average Ambient DO
6.55
6.37
6.18
5.99
6.5
6.26
6.07
5.89
5.70
6.0
5.90
5.71
5.53
5.34
5.5
5.54
5.35
5.17
4.97
5.0
5.17
4.99
4.80
4.61
"Shaded values indicate a DO concentration above the State standard of 5.0 mg /L.
Pecan Grove Marina - Proposed Marina Basin
DISSOLVED
OXYGEN
(mg /L)
SEDIMENT OXYGEN DEMAND (g 02/M2 /day)
1.5
2.0
2.5
3.0
8.0
6.73
6.37
6.00
5.63
7.5
6.50
6.13
5.77
5.40
7.0
6.27
5.90
5.54
5.17
6.9
Average Ambient DO
6.22
5.86
5.49
5.12
6.5
6.04
5.67
5.31
5.00
6.0
5.81
5.44
5.07
4.71
5.5
5.57
5.21
4.84
4.48
5.0
5.34
5.00
4.61
4.25
'Shaded values indicate a DO concentration above the State standard of 5.0 mg /L.

0
`Boundaimb die dPPrUxlrndLU dnU dre
not meant to be absolute.
SITE
Map Source: Oriental Quadrangle 7.5 minute (topographic) 1990.
SCALE 1" = 1000'
Pecan Grove Marina
Pamlico County, NC LMG Figure 1.
02 -05 -232 LAND MANAGEMENT GROUP USGS Topgraphic Map
Environmental Consultants
June 2007

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iiiii
*Boundaries are approximate and are -71-� S
not meant to be absolute. ��cr SCALE 1" = 1000'
Map Source: 1998 NAPP aerial photography
Pecan Grove Marina Figure 2.
Pamlico County, NC LMG Ambient Water Quality
02 -05 -232 LAND MANAGEMENT GROUP me
Environmental Consultants Sampling Stations
June 2007