NC0026611_Report_20011130

NPDES DOCUMENT 5CANNINO COVER !;CIEET
Permit:
NC0026611
Morehead City WWTP
NPDES
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Report
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
November 30, 2001
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Division of Water Quality
November 30, 2001
MEMORANDUM
To: Rick Shiver
From: Harold Quidley
Through: Dianne ReiciV
Subject: Calico Creek Water Quality Study September 2001
Morehead City WWTP (#NC0026611)
Sub Basin 03-05-03
DEC - 6 2001
DENR - WATER OUALITY
POINT SOURCE BRANCH
Accompanying this memo are the results from the Calico Creek water quality study conducted by
the Environmental Sciences Branch on September 26, 2001. The purpose of the study was to provide
an updated water quality assessment of Calico Creek in regard to NPDES permit renewal for the
Morehead City WWTP. Chemical data indicates that the Morehead City WWTP effluent continues to
contribute to nutrient loading in Calico Creek. As shown during previous water quality studies
conducted on Calico Creek by the Division of Water Quality, effluent remains in Calico Creek for a
prolonged period of time due to the actions of the tide. The study included high and low tide sampling
at 8 Calico Creek stations, 2 background stations and from the Morehead City WWTP effluent prior to
discharge. Parameters consisted of BODS, N&P, fecal, depth integrated physical profiles and cross -
sections. Also included in the report are tables and figures showing the resulting data and a map of the
survey area showing station locations. If you need additional information or clarification regarding the
Calico Creek study please contact Dianne Reid or Harold Quidley at [phone].
cc: Jay Sauber1
Jimmie Overton
Jackie Nowell
Rich Gannon
•
Environmental Sciences Branch Water Quality Section

Calico Creek Study — September 26. 2001
On September 26, 2001, Environmental Sciences Branch staff (DWQ) conducted a water
quality study on Calico Creek, receiving waters for the Morehead City WWTP (NC0026611).
Calico Creek is located in the White Oak Basin and is currently classified as SC HQW. The
purpose of the study was to provide an updated water quality assessment of Calico Creek in
regard to NPDES permit renewal for the Morehead City WWTP. The 1.7 mgd facility is
scheduled for permit renewal during the fall of 2002. DWQ previously conducted intensive
studies on Calico Creek, during December 1977, August/September 1981 and September 1988.
As shown during the previous water quality studies, effluent remains in Calico Creek for a
prolonged period of time due to the actions of the tide and continues to significantly contribute to
nutrient loading in Calico Creek.
Paramedic coverage for the September 2001 study included BOD5, nutrients, coliform and
physical measurements (D.O., pH, temperature, conductivity and salinity) at Calico Creek
stations and from the WWTP effluent. Calico Creek is tidally influenced; therefore two Calico
Creek sampling runs were performed during the study, the first at low tide (approximately 10:00
am), and the second at high tide (approximately 4:30 pm). Samples were collected at seven
Calico Creek stations established by DWQ during the previous studies (Figure 1).
Cross-section measurements were also taken at each station using a laser range finder. A
staff -plate as temporarily installed at Piggotts Bridge and monitored throughout the day of the
study to determine relative tidal amplitude. The staff -plate indicated a maximum low to high
tidal amplide of feet:
Tide Table for Sept 26, 2001
High 3:54 am
Low 9:57 am
High 4:30 pm
Low 10:55 pm
Sampling tation locations are as follows:
Station Location Coordinates
CO Calico Cr. 1945 ft upstream from outfall (Lat 34° 44' 02' Long 76° 44' 34')
C1 Calico Cr. at influent pipe (Lat 34° 43' 10' Long 76° 44' 44")
C2 Calico Cr. near WWTP effluent pipe (Lat 34° 43' 54' Long 76° 44' 14')
C$ Calico Cr. 400 feet dns effluent pipe (Lat 34° 43' OrLong 76° 44' 42')
C4 Calico Cr. 2000 feet dns effluent pipe (Lat 34° 43' 48' Long 76° 43' 13')
C Calico Cr. SR1176 bridge (Piggotts Bridge) (Lat 34° 43' 48' Long 76° 43' 53')
C Calico Cr. at Morehead City School (Lat 34° 43' 41' Long 76° 43' 30')
Q7 Calico Cr. at SC/SA line markers (Lat 34° 43' 48' Long 76° 42' 36")
BR1 Crab Point Bay (background site 1) (Lat 34° 44' 18" Long 76° 43' 30")
BR2 Crab Point Bay (background site 2) (Lat 34° 44' 28' Long 76° 43' 27')
Fecal coliform samples were collected during the first sampling run only (low tide). The coliform
samples were delivered to Mr. George Gilbert (Shellfish Sanitation Lab, Morehead City) for analysis
inunediately following the first run.
Chemical/Physical Data
Chemical data indicates that the Morehead City WWTP effluent continues to contribute to
nutrient loading in Calico Creek (Table 1). This is particularly evident during low tide when in-

stream waste concentration is highest. Figures 2 through 5 show high tide and low tide nutrient
values (NH, TKN, NOX and P total) for the seven Calico Creek stations sampled during the
October 26,' 2001 study. Previous water quality, and rhodamine dye studies conducted by DWQ have
shown that effluent remains in Calico Creek for a prolonged period of time due to the actions of the
tide. These studies indicated that several tidal periods are required to flush a slug of waste out of
Calico Creek. The effects of tide on in -stream waste concentration are clearly shown in Figures 2
through 5. At low tide nutrient values are very elevated near the WWTP outfall and decrease in
downstream order to near background levels at the farthest station downstream (station C7). During
high tide the nutrient values are considerably lower at all stations downstream from the WWTP
outfall due to dilution of the effluent. The most elevated values during high tide occur upstream
from the outfall where the incoming tide carries the effluent into the much narrower headwaters
where there is less dilution.
Two background stations (reference sites) located near Crab Point Bay (BG1 and BG2) were also
sampled during high and low tide. The background sites were selected to provide comparison data
from similar creeks in the area that are not influenced by municipal wastewater. Nutrient data from
BG1 and BG2 are presented in Table 2. As shown in Table 2, nutrient values from the background
stations are considerably lower than values detected in the mid to upper reach of Calico Creek.
Nutrient levels from BG1 and BG2 are generally similar to values detected at C7 near the mouth of
Calico Creek where the presence of wastewater is less detectable.
Effluent samples were collected prior to discharge from the Morehead City WWTP during the
high and low tide sampling events (Table 3). Effluent values for NH3 were 0.89 mg/L during low
tide samping and 1.1 mg/L during the high tide sampling. Self -monitoring data for the Morehead
City facility indicates an average NH3 of 1.42 mg/L for the month of September 2001. There are
currently no NH3 limits for the facility. However, NPDES permit limitations for NH3 (summer) will
be 1.0 mg/L upon issuance of the 2002 permit. TKN values at low and high tide were 2.5 mg/L and
3.4 mg/L, respectively. NOX and P total values were consistent during both sampling events at 14.0
mg/L N(30) and 3.5 mg/L total P.
BOD5 values for Calico Creek stations and the Crab Point Bay background stations were low
with most samples being reported at levels not detected above the DWQ practical quantitation limit.
BOD5 effluent values were 9.2 mg/L during low tide sampling and 3.2 mg/L during high tide
sampling, both within current permit limitations. NPDES permit limitations for BOD5 (summer)
will be 5.0 mg/L upon issuance of the 2002 permit. Self -monitoring data indicates 10.1 mg/L
average BOD5 for the month of September.
Depth integrated physical measurements (D.O., pH, temperature, conductivity and salinity) were
taken at Calico Creek stations during low and high tide (Table 4). Stratification of the water column
was observed, particularly in regard to D.O., conductivity and salinity.
Physical parameters indicate significant differences at all stations between low and high tide
(Table 5, Figure 6). As noted during previous studies, the main impacts on D.O. in Calico Creek
come frorf oxygen consuming wastes and the diurnal fluctuations associated with eutrophication.
During low tide, D.O. levels are much lower than during high tide due to decreased dilution of
the wastewater. At low tide surface D.O. at the seven Calico Creek stations ranged from 5.3 mg/L at
Cl, the most upstream station, to 2.6 mg/L at Piggots Bridge (C5). A D.O. sag is evident in the area
of Piggotts Bridge (C5) during low tide (Figure 6 and Table 4) with a surface value of 2.6 mg/L and
a bottom value of 1.5 mg/L. Another area of depressed D.O. is evident during low tide in the
shallow
ater at C2, 250 feet upstream from the outfall.
At high tide, surface D.O. ranged from 6.5 mg/L to 5.3 mg/L. Diurnal fluctuation may have
contributed to the decreased D.O levels during low tide because it occurred during the morning

hours when D.O. values may have been depressed due to the affects of respiration and
photosynthesis by phytoplankton. Green water, indicative of algal productivity, was noted in Calico
Creek during the study.
On September 20, 2001, one week prior to the September 26 Calico Creek study, a pre -survey
was conducted of the Morehead City area to assess potential boat ramps and general station access.
During the pre -survey, physical parameters (surface and bottom only) were measured at the seven
Calico Creek stations during high tide and are also included with this report in Table 6.
Fecal coliform samples were collected at all stations during the low tide sampling event and
delivered to Mr. George Gilbert (Shellfish Sanitation Lab, Morehead City) for analysis. Fecal
coliform and E. Coli results in Calico Creek ranged from >1600 at stations CO and Cl, upstream
from the WWTP outfall, to 23 at the farthest downstream station C7 (Table 4). Fecal coliform and
E. coli values were <1.8 in the WWTP effluent at the time of the high and low tide sampling.
Cross-s tion measurements provided a relative indication of the water surface during low and
high tide in relationship to the bottom profile at each station. Cross-section data showed relatively
similar wid s and depths to those that had been reported during previous studies indicating little
physical ch nge in channel characteristics in Calico Creek. During low tide, at stations upstream
from Piggots Bridge (C5), the water surface is generally confined to a relatively narrow and very
shallow channel, and does not extend into the marsh. During high tide, the volume of water in
Calico Crek is significantly increased and the water surface extends out of the channel and into the
wide expanse of marsh. For example, Cl cross-section data indicated a maximum depth of only 0.9
feet and a cannel width of 52 feet during low flow. At the same site during high flow, maximum
depth was 3.5 feet in the channel and width extending into the marsh to 442 feet.

Figure 1 - Calico Creek Study Sites
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Table 1
Calico Creek Study - September 26, 2001
Chemical Data for Calico Creek Stations (NH3, TKN, NOX, P Total) at High Tide and Low Tide
NH3
NH3
TKN
TKN
NOX
mg/L
NOX
mg/L
P Total
mg/L
Low Tide
P Total
mg/L
High Tide
Station
Location
mg/L
Low Tide
mg/L
High Tide
mg/L
Low Tide
--mg/L
High Tide
Low Tide
High Tide
0
Calico 9000 ft upstream from outfall
1.10
0.96
2.7
2.1
0.13
2.50
0.87
0.98
1
Calico at influent pipe crossing
1.20
0.56
2.2
1.3
1.20
1.80
1.10
0.57
2
Calico 20 ft from end of outfall pipe
0.97
0.38
2.8
1.0
5.60
0.80
1.90
0.31
3
Calico 400 ft downstream from outfall
1.00
0.31
2.7
1.0
4.50
0.27
1.70
0.19
4
Calico 2000 downstream from outfall
1.10
0.21
2.1
0.7
3.30
0.13
1.30
0.11
5
Calico at SR1172 (Piggotts Bridge)
0.90
0.19
2.0
0.7
1.90
0.11
0.84
0.10
6
Calico near City School
0.64
0.20
1.2
0.6
1.10
0.08
0.57
0.09
7
Calico at SC/SA line markers
0.41
0.09
0.4
0.5
0.22
0.02
0.04
0.04
Table 2
Calico Creek Study - September 26, 2001
Chemical data for 2 Background Stations (Crab Point Bay) (NH3, TKN, NOX, P Total) at High Tide and Low Tide
Station Location
BG1 Crab Point Bay (background site 1)
BG2 Crab Point Bay (background site 2)
NH3 NH3
mg/L mg/L
Low Tide High Tide
0.20 0.07
0.48 0.07
TKN TKN
mg/L mg/L
Low Tide High Tide
1.2 0.6
1.0 0.8
Table 3
Calico Creek Study - September 26, 2001
Chemical data for Morehead City WWTP Effluent (NH3, TKN, NOX, P Total) at High Tide and Low Tide
(Sampled prior to discharge)
Station Location
IC-EFF Morehead City WWTP effluent
NOX NOX
mg/L mg/L
Low Tide High Tide
0.01 0.01
0.01 0.01
P Total P Total
mg/L mg/L
Low Tide High Tide
0.18 0.04
0.12 0.05
NH3 NH3
mg/L mg/L
Low Tide High Tide
0.89 1.1
TKN TKN
mg/L mg/L
Low Tide High Tide
_2.5 3.4
NOX NOX
mg/L mg/L
Low Tide High Tide
14.00 14.00
P Total P Total
mg/L mg/L
Low Tide High Tide
3.50 3.50

Figure 2 Figure 3
1.40
1.20
J 1.00
r 0.80
= 0.60
Z 0.40
0.20
0.00
Calico Creek NH3 Data 10/26/2001
(WWTP outfall)
Low Tide
High Tide
0 1 2 3 4 5 6 7
Stations
3.0
2.5
2.0
rn
E 1.5
Z
I- 1.0
0.5
0.0
0
Calico Creek TKN Data 09/26/01
(WWTP outfali)
Low Tide
High Tide
1 2 3 4 5 6 7
Stations
Figure 4 Figure 5
Calico Creek NOX Data 01/26/01
(WWTP outfall)
3 4
Stations
2.00
To 1.00
0
t`
a 0.50
0.00
Calico Creek P Total Data 09/26/01
(WWTP outtall)
0 1 2 3 4 5 6 7
Stations

Table 4
Calico Creek Study - September 26, 2001
Physical Parameters for High Tide and Low Tide (showing depth profiles)
Station Location Tide Date Time Depth (M) D.O. Temp pH Cond Salinity Fecal E coli
MPN /looml
CO Calico 1945 ft upstream from outfall Low 09/26/2001 1150 0.1 5.3 23.8 7.8 10340 5.9 1600 >1600
CO Calico 1945 ft upstream from outfall High 09/26/2001 1455 0.1 5.3 23.6 7,3 38630 -24.5
CO Calico 1945 ft upstream from outfall High 09/26/2001 1455 0.8 5.5 23.4 7.4 43450 28.2
C1 Calico at influent pipe crossing Low 09/26/2001 0930 0.1 3.0 20.2 7.0 22810 13.5 1600 1600
C1 Calico at influent pipe crossing High 09/26/2001 1455 0.1 6.1 23.3 7.6 40780 29.5
C1 Calico at influent pipe crossing High 09/26/2001 1455 0.9 5.7 23.4 7.6 46130 29.9
C2 Calico 20 ft from end of outfall pipe Low 09/26/2001 0950 0.1 4.8 21.0 7.3 18340 11.1 540 350
C2 Calico 20 ft from end of outfall pipe Low 09/26/2001 0950 0.7 3.9 20.8 7.2 21000 12.7
C2 Calico 20 ft from end of outfall pipe High 09/26/2001 1555 0.1 6.5 23.3 7.6 31170 24.5
C2 Calico 20 ft from end of outfall pipe High 09/26/2001 1555 1.0 5.6 23.3 7.6 46790 27.4
C2 Calico 20 ft from end of outfall pipe High 09/26/2001 1555 1.7 5.5 23.3 7.6 46480 30.2
C3 Calico 400 ft downstream from outfall Low 09/26/2001 1000 0.1 4.6 21.0 7.3 20300 12.0 920 540
C3 Calico 400 ft downstream from outfall High 09/26/2001 1600 0.1 5.8 23.3 7.6 45960 29.7
C3 Calico 400 ft downstream from outfall High 09/26/2001 1600 1.0 5.5 23.3 7.6 46830 30.5
C4 Calico 2000 downstream from outfall Low 09/26/2001 1010 0.1 3.4 20.8 7.2 27760 17.0 350 350
C4 Calico 2000 downstream from outfall High 09/26/2001 1.610 0.1 6.0 23.3 7.7 47280 30.8
C4 Calico 2000 downstream from outfall High 09/26/2001 1610 1.0 5.8 23.3 7.7 47990 31.3
C5 Calico at SR1172 (Piggotts Bridge) Low 09/26/2001 1020 0.1 2.6 20.8 7.2 37420 23.6 350 170
C5 Calico at SR1172 (Piggotts Bridge) Low 09/26/2001 1020 1.0 2.2 20.9 7.1 40040 25.5
C5 Calico at SR1172 (Piggotts Bridge) Low 09/26/2001 1020 1.6 1.5 20.9 7.1 41440 26.9
C5 Calico at SR1172 (Piggotts Bridge) High 09/26/2001 1615 0.1 6.0 23.3 7.7 47450 30.9
C5 Calico at SR1172 (Piggotts Bridge) High 09/26/2001 1615 1.0 6.0 23.3 7.7 48030 31.3
C5 Calico at SR1172 (Piggotts Bridge) High 09/26/2001 1615 2.0 5.9 23.2 7.8 48700 31.8
C6 Calico near City School Low 09/26/2001 1030 0.1 3.8 20.3 7.2 40530 25.8 350 170
C6 Calico near City School High 09/26/2001 1625 0.1 6.0 23.3 7.7 48070 31.3
C6 Calico near City School High 09/26/2001 1625 1.0 5.6 23.1 7.8 48880 31.9
C7 Calico at SC/SA line markers Low 09/26/2001 1040 0.1 4.3 21.0 7.4 45680 29.6 23 23
C7 Calico at SC/SA line markers Low 09/26/2001 1040 0.6 4.4 20.9 7.4 46810 31.4
C7 Calico at SC/SA line markers High 09/26/2001 1635 0.1 6.5 23.4 7.8 48910 31.9
C7 Calico at SC/SA line markers High 09/26/2001 1635 1.0 5.7 23.7 7.9 50150 32.8
C7 Calico at SC/SA line markers High 09/26/2001 1635 1.3 5.4 23.8 7.9 50300 33.0
C-EFF Morehead City WWTP effluent 09/26/2001 0945 effluent 8.1 22.0 7.7 3030 <1.8 <1.8
C-EFF Morehead City WWTP effluent 09/26/2001 1455 effluent 8.5 22.9 8.1 3090 ns ns

Table 5
Calico Creek Study - September 26, 2001
Physical Parameters for High Tide and Low Tide (Showing surface measurements only)
Station
Location
Tide
Date
low/high
Time
Depth (M)
Low Tide
D.O.
Hlgh Tide
D.O.
Low Tide
Temp
Hlgh Tide
Temp
Low Tide
pH
Hight Tide
pH
Low Tide
Cond
High Tide
Cond
Low Tide
Salinity
High Tide
Salinity
0
Calico ]945 ftupstream from outfall
Low/High
09/26/2001
1150/1730
0.1
5.3
5.3
23.8
23.5
7.8
7.3
10340
38630
5.9
13.5
11.1
12.0
17.0
23.6
25.8
29.6
24.5
1
2
3
4
5
6
7
Calico at influent pipe crossing
Calico 20 ft from end of outfall pipe
Calico 400 ft downstream from outfall
Calico 2000 downstream from outfall
Calico at SR1172 (Piggotts Bridge)
Calico near City School
Calico at SC/SA line markers
Low/High
09/26/2001
0935/1545
0.1
3.0
6.1
20.2
23.3
7.0
7.6
22810
40780
Low/High
09/26/2001
0950/1555
0.1
4.8
6.5
21.0
23.3
7.3
7.6
18340
31170
Low/High
09/26/2001
1000/1600
0.1
4.6
5.8
21.0
23.3
7.3
7.6
20300
45960
Low/High
09/26/2001
1010/1610
0.1
3.4
6.0
20.8
23.3
7.2
7.7
27760
47280
Low/High
09/26/2001
1020/1615
0.1
2.6
6.0
20.8
23.3
7.2
7.7
37420
47450
Low/High
09/26/2001
1030/1625
0.1
3.8
6.0
20.3
23.3
7.2
7.7
40530
48070
Low/High
09/26/2001
1040/1635
0.1
4.3
6.5
_21.0
23.4
7.4
7.8
45680
48910
Figure 6
Surface D.O.values for Calico Creek
High and Low Tide 09/26/2001
(WWTP outlall)
7.0
6.0
-J 5.0:1
0) 4.0
3.0
0 2.0
1.0
0.0
• 0 1 2 3 4 5 6 7
stations
High Tide ;

Table 6
Calico Creek Pre -Survey - September 20, 2001
Physical Parameters for High Tide only (surface and bottom readings only)
Station Location
Tide Date Time Depth (M) D.O. Temp pH Cond
C1 Calico at influent pipe crossing High 09/20/2001 1050 0.1 5.1 23.5 7.1 45,000
uentpipe crossing High 09/20/2001-1050 0,8 5.0 23.5 7.6 45,000
C3 Calico 400 ft downstream from outfall High 09/20/2001 1100 0.1 4.9 23.7 7.4 45,320
C3 Calico 400 ft downstream from outfall High 09/20/2001 1100 0.9 5.5 23.5 7.4 45,000
C4 Calico 2000 downstream from outfall High 09/20/2001 1110 0.1 5.3 23.7 7.6 45,150
C4 Calico 2000 downstream from outfall High 09/20/2001 1110 1.1 5.4 23.7 7.6 45,800 •
C5 Calico at SR1172 (Piggotts Bridge) High 09/20/2001 1120 0.1 5.4 23.6 7.6 45,190
C5 Calico at SR1172 (Piggotts Bridge) High 09/20/2001 1120 1.8 5.5 23.6 7.7 45,360
C6 Calico near City School High 09/20/2001 1125 0.1 6.2 23.7 7.7 45,300
C6 Calico near City School High 09/20/2001 1125 0.9 6.1 23.7 7.7 45,210
C7 Calico at SC/SA line markers High 09/20/2001 1135 0.1 7.4 24.0 7.8 47,190
C7 Calico at SC/SA line markers High 09/20/2001 1135 1.4 7.6 24.0 7.8 47,350
C-EFF Morehead City WWTP effluent
09/20/2001 1400 effluent 7.4 24.9 7.9 640