NC0031836_Report_19900202

NPDES DOCUNENT SCANNING COVER SHEET
NPDES Permit:
NC0031836
Fourth Creek WWTP
Document Type:
Permit Issuance
Wasteload Allocation
Authorization to Construct (AtC)
Permit Modification
Complete File - Historical
Engineering Alternatives (EAA)
Correspondence
Owner Name Change
& r 71-
Instream Assessment (67b)
Speculative Limits
Environmental Assessment (EA)
Document Date:
February 2, 1990
Thin document its printed on reuse paper - isgnore any
content on the re-srerse side

DIVISION OF ENVIRONMENTAL MANAGEMENT
February 2, 1990
MEMORANDUM
TO: Rex Gleason
Dennis Ramsey
FROM: Steve W. Tedder
SUBJECT: Toxicological Evaluation - Statesville -Fourth Creek WWTP
Attached is the final report concerning an intensive toxicological eval-
uation of the Statesville -Fourth Creek WWTP.
If there are any questions, please contact myself or Ken Eagleson at
[phone].
SWT:ps
cc:
Ken Eagleson
Larry Ausley
Bob DeWeese
Trevor Clements
Jay Sauber
Jim Overton
Central Files
V'bp91990
�U�ti tia
00
1�V

Statesville Fourth Creek WWTP
Toxicity Examination
NPDES # NC0031836
Basin 030706
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North Carolina Department of Environment,
Health, and Natural Resources
Water Quality Section
January, 1990

TABLE OF CONTENTS
Introduction 1
Toxicity Examination 4
Chemical Sampling 6
Benthic Macroinvertebrate Analysis 11
Conclusions 13
Recommendations 14
References 15
Appendices 16
Ceriodaphnia dubia Test Procedure
Ceriodaphnia Reproduction Test Procedure
Compliance Evaluation Analysis Report (December 1988-October 1989)
Benthic Macroinvertebrate Procedure
Benthic Macroinvertebrate Taxa Richness for Fourth Creek.
List of Definitions
LIST OF FIGURES
Figure 1. Statesville Fourth Creek WWTP Study Area 2
Figure 2. Schematic Diagram of Statesville Fourth Creek WWTP 3
Figure 3. Seven Day Ceriodaphnia Mean Cumulative Reproduction 5
LIST OF TABLES
Table 1. Previous Toxicity Testing Results for Statesville Fourth Creek WWTP 4
Table 2. Chemical Sampling Site Descriptions 6
Table 3. Chemical Analyses Results —Statesville Fourth Creek WWTP 7-8
Table 4. Organic Analyses Results —Statesville Fourth Creek WWTP 10
Table 5. Physical Description of Macroinvertebrate Sampling Stations 12
Table 6. Macroinvertebrate Summary Statistics 12

INTRODUCTION
An intensive on —site toxicological evaluation was conducted at the Statesville Fourth Creek Wastewater Treatment
Plant, Iredell County (NPDES# NC0031836) from June 19 through June 24, 1989. This report contains findings of
toxicological, chemical , and benthic macroinvertebrate evaluations performed including the following:
1) 48-hour static Ceriodaphnia dubia toxicity tests on wastewater treatment plant influent and effluent to determine
acute toxicity;
2) 24-hour static pass/fail toxicity test using Pimephales promelas (fathead minnows) on final effluent to determine
acute toxicity;
3) Seven-day Ceriodaphnia dubia static replacement reproduction suppression toxicity test on final effluent to
determine levels of chronic lethality and reproduction suppression;
4) Analysis of benthic macroinvertebrates present in the receiving stream both above and below the treatment
facility;
5) Analysis of chemical samples collected from the WWTP influent and effluent, receiving stream above and below
the discharge, and toxicity test dilution water source.
The Statesville Fourth Creek WWTP receives domestic and commercial waste from the city of Statesville. The facility
operates under N.P.D.E.S. permit number NC0031836, which was issued December 1, 1987, and expires November 30,
1992. The permitted effluent flow for the WWTP is 4.0 million gallons per day (MGD). Effluent is discharged to Fourth
Creek, which is classified as Class "C" waters in the Yadkin -Pee Dee River basin. At the discharge point the creek has a 7
day-10 year low flow (7Q10) of 11.0 cubic feet per second (CFS), yielding an instream waste concentration (IWC) of the
effluent during low flow conditions of 36%. The study area and sampling locations used for this evaluation are presented
in Figure 1.
The facility operates waste treatment processes consisting of an influent lift station, grit removal chamber, dual
aeration basins, dual clarifiers with sludge returns, sludge dewatering unit, effluent chlorination, post aeration, and sludge
drying beds. An additional clarifier and sludge treatment consisting of an aerobic digestor and a sludge press are under
construction. Upon completion of these processes, the facility's design flow will be 6.0 MGD. At this increased flow, the
facility IWC will become 46%. Figure 2 presents a schematic diagram of the functional treatment works.

Figure 1. Statesville Fourth Creek WWTP Study Area and Sampling Stations
-77
I - 4 0
City of
Statesville
US 70
NC 115
-77
SR 2354
SR 2342
NC 115
Fifth Creek
SR 2158
Fourth Creek
Station 04
SR 2158
SR 2169
US 64
SR 2160 stream flow
SR 2316
Station 01 Station 02
stream flov1 Statesville Fourth
Creek WWTP
SR 2355
Statesville
Third Creek WWTP
Third Creek
SR 2318
SR 2360
SR 2359
I - 4 0
Station 03
SR 2308
SR 2313
US 70

Figure 2. Flow Diagram of Statesville Fourth Creek WWTP
•
Aeration Basin
Influent
Sampling
Station
0.1
Distribution
Box
Aeration Basin
Influent
Pump Station
Return Sludge
Final Clarifier
Final Clarifier
Waste Sludge
Sludge Drying Beds '
Chlorine
Contact
Chamber
,,, -Effluent
Sampling
Station
Parshall
Flume
Discharge to
Fourth Creek

TOXICITY EXAMINATION
Since December 1, 1987, the facility has been required by its permit to monitor chronic toxicity with a target chronic
limit of 36% effluent. This requires self -monitoring Pass/Fail chronic toxicity tests to be performed on a quarterly basis
and result in no significant mortality or reproduction suppression to Ceriodaphnia dubia at this effluent concentration.
The results of all self -monitoring toxicity tests reported for the facility are presented in Table 1.
Table 1. Self -Monitoring Toxicity Test Results -Statesville Fourth Creek WWTP.
Test Date Result Test Date Result
January 1988 Fail February 1989 Fail
March 1988 Fail March 1989 Bad test
April 1988 Fail April 1989 Fail
June 1988 Fail May 1989 Fail
July 1988 Fail June 1989 Fail
August 1988 Fail July 1989 Fail
October 1988 Fail August 1989 Fail
December 1988 Pass September 1989 Fail
January 1989 Fail October 1989 Fail
Four toxicity tests were conducted during the on -site toxicological evaluation: one 24-hour acute pass/fail toxicity
test using Pimephales promelas (fathead minnows), two Ceriodaphnia dubia 48-hour static toxicity tests, and a 168-hour
static renewal reproduction suppression toxicity test using the cladoceran Ceriodaphnia dubia. Final effluent samples
were collected below the chlorine contact chamber, at the head of the parshall flume. Dilution water was obtained from
Fifth Creek at SR 2158 (Iredell County). This dilution water was tested prior to use in the on -site investigation with the
Ceriodaphnia dubia reproduction suppression toxicity test and yielded reproduction results similar to those in Aquatic
Toxicology Laboratory cladoceran culture water.
The fathead minnow 24-hour acute pass/fail toxicity test had no mortality of test organisms exposed to 90% effluent.
Therefore, the test result was "Pass." The fathead minnows used in this test were 15 days old at test initiation.
Ceriodaphnia dubia 48-hour static toxicity tests were conducted while on -site using a 24-hour composite effluent
sample and an instantaneous grab sample of the influent. The resulting 48 hour LC50s were 34% for the influent test and
37% for the effluent test. A seven-day static renewal, Ceriodaphnia dubia reproduction suppression toxicity test was
performed from June 19 through June 26, 1989. Ceriodaphnia dubia exposed to effluent concentrations up to and
including 10% had similar mean overall reproduction and survival when compared to control organisms. An average of 4.0

Average young per female
Figure 3. Ceriodaphnia Mean Cumulative Reproduction for
Statesville Fourth Creek WWTP Chronic Toxicity Test.
1.0
2.0
3.0
Day
4.0
5.0
6.0
7.0
— -- Control
—0-- 1.0%
—a-- 10%
--0— 25%
36%
--17.3.- 5090
---0 — 75%
-1(6- 10(Y'Io
—5—

young were produced per female exposed to 25% effluent, compared to averages of 30.4 young per female exposed to
10% effluent and 33.7 young per control female. This implies that the discharge would cause a chronic impact to sensitive
species in the receiving stream at 7010 flow conditions. Mean cumulative reproduction from this test is depicted in
Figure 3. The No Observed Effect Concentration (NOEL) was 10% based on mortality and reproduction , and the Lowest
Observed Effect Concentration (LOEC) was 25%. A Chronic Value of 15.8% was calculated from this data as defined in
EPA document 600/4-85/0141.
CHEMICAL SAMPLING ANALYSIS
Samples of final effluent, influent, toxicity test dilution water, and the receiving stream above and below the
discharge were collected for chemical analysis on two dates during the on -site evaluation. These samples were analyzed
at the Division of Environmental Management Chemistry Laboratory. Sampling stations are described in Table 2 and
presented schematically in Figure 1. All samples were collected as instantaneous grabs with the exception of Station 02
(effluent toxicity test sampling point), which was sampled as 24-hour composites. Results of chemical analyses are given
in Table 3.
Table 2. Chemical Sampling Site Descriptions
Station Location
01 Fourth Creek at Iredell Co. SR 2316, upstream of the Statesville Fourth Creek WWTP.
02 Statesville Fourth Creek WWTP final effluent at head of parshall flume, below post -aeration chamber.
02A Statesville Fourth Creek WWTP influent at manhole above influent distribution box.
03 Fourth Creek at Iredell Co. SR 2308, downstream of the Statesville Fourth Creek WWTP discharge.
04 Fifth Creek at Iredell Co. SR 2158.
Analyses for metals revealed that copper was being discharged into Fourth Creek at a concentration of 14 ppb in the
effluent (02) sample of June 22, 1989. This value would not be expected to exceed the N.C. Water Quality Action Level
of 7 ppb for copper at 7Q10 receiving stream conditions. Copper was not detectable in the downstream station sample of
June 22, but it was detected at 11 ppb on June 24 at 2 ppb. Influent copper concentrations on June 22 and 24 were 14
ppb and 940 ppb, respectively. No copper was detected at the upstream (01) or dilution (04) sites on either sampling day.
At a hardness of 50 mg/I CaG03, EPA2 recommends a maximum copper concentration of 6.5 ppb as a four -day average
not to be exceeded more than once in three years and a level of 9.2 ppb as a one -hour average not to be exceeded more
than once in three years. They reported acute LC50's ranging from 6.5 ppb for Daphnia magna to 10,200 ppb for the
bluegill sunfish in hard water. Chronic toxicity values ranged from 3.9 ppb for the northeen pike to 60.82 ppb for the brook
trout. Actual toxic levels in an effluent depend on bioavailability, which is a factor of the physical and chemical properties of
the effluent.

Table 3. Chemical Analysis Results -Statesville Fourth Creek WWTP
Permitted Flow (MGD)
11.0
7Q10 (cfs
4.0Id
-Instream Waste Conc. (°/0)
36.0
Upstream
Effluent
Influent
Downstream
Dilution
Chemical/Physical
Units
Water Qual.
Sta 01
Sta 02
Sta 02A
Sta 03
Sta 04
Analyses
Standards
890622
890622
890622
890622
890622
BCD
PPM
2.3
42
150
4.2
1.2
CCU
PPM
21
170
480
34
16
Coliform:MF Fecal*
#/100m1
12000
230
16000
Residue TOTAL
PPM
260
390
440
330
160
volatile
PPM
35
100
270
' 49
30
fixed
PPM
230
290
170
280
130
Residue SUSPENDED
PPM
150
150
110
210
72
volatile
PPM
22
98
84
32
14
fixed
PPM
120
54
24
180
58
pH
std. units
6.0-9.0
7.4
6.7
7.1
7.0
7.2
Acidity
PPM
2
21
24
7
1
Alkalinity
PPM
25
57
110
28
23
Chloride
PPM
230(AL)t
30
Cyanide
PPB
5
<10
Formaldehyde
PPM
1.1
Grease and Oils*
PPM
<1
Hardness
PPM
31
38
36
29
23
Specific Conductance
uMhos/cm
88
370
410
98
82
M BAS
PPM
0.5
0.1
Phenols
PPB
2
NH3 as N
PPM
0.08
0.36
13
0.12
0.04
TKN
PPM
0.6
4.6
85
0.8
0.4
NO2 plus NO3 as N
PPM
0.82
0.27
0.03
0.78
0.43
P: Total as P
PPM
0.3
3.6
2.8
0.4
0.14
Cadmium
PPB
2
<2.0
<2.0
<2.0
<2.0
<2.0
Chromium (Total)
PPB
50
<25
<25
<25
<25
<25
Copper
PPB
7(AL)t
<2.0
14
14
<2.0
<2.0
Nickel
PPB
88
<10
21.0
76
12
<10
Lead
PPB
25
<10
<10
<10
<10
<10
Zinc
PPB
50(AL)t
45
66
<10
<10
<10
Silver
PPB
0.06(AL)t
<5.0
<5.0
<5.0
<5.0
<5.0
Aluminum
PPB
23000
1200
2600
25000
11000
Iron
PPB
1000(AL)t
20000
1200
720
21000
9800
Manganese
PPB
250
14.0
120
270
170
Mercury
PPB
0.012
<0.2
0.2
) <0.2
<0.2
<0.2
* Grab sample taken for analysis.
t Values represent action levels as s ecified in NC Administrative Code
Section 15 NCAC 2B .0211 b 4
Fresh Surface Water Classifications and Standards
-7-

Table 3. Chemical Analysis Results -Statesville Fourth Creek WWTP
Permitted Flow (MGD)
11.00
7Q10 (cfs)
4.00
Instream Waste Conc. (%)
36.05
Upstream
Effluent
Influent
Downstream
Dilution
Chemical/Physical
Units
Sta 01
Sta 02
Sta 02A
Sta 03
Sta 04
Analyses
890624
890624
890624
890624
890624
CCD
PPM
16
47
230
20
9
Residue TOTAL
PPM
160
250
600
200
110
volatile
PPM
29
45
250
35
23
fixed
PPM
140
200
360
160
87
Residue SUSPENDED
PPM
81
18
46
100
' 39
volatile
PPM
10
13
32
14
9
fixed
PPM
71
5
14
88
42
pH
std. units
6.3
7.3
3.2
6.5
6.5
Acidity
PPM
9
5
120
11
16
Alkalinity
PPM
30
63
33
28
Chloride
PPM
28
Cyanide
PPB
<10
Formaldehyde
PPM
1.8
Grease and Oils*
PPM
<1
Hardness
PPM
41
37
120
46
31
Specific Conductance
uMhos/cm
100
340
960
120
85
MBAS
PPM
<0.1
Phenols
PPB
7
NH3asN
PPM
0.04
0.61
8
0.1
0.04
TKN
PPM
0.2
3.7
13
0.6
0.2
NO2 plus NO3 as N
PPM
0.84
0.18
0.1
0.71
0.49
P: Total as P
PPM
0.13
0.83
32
0.31
0.09
Cadmium
PPB
<2.0
<2.0
45
<2.0
<2.0
Chromium (Total)
PPB
<25
<25
62
<25
<25
Copper
PPB
<2.0
5.3
940
2
<2.0
Nickel
PPB
<10
200
1100
11
<10
Lead
PPB
<10
<10
37
<10
<10
Zinc
PPB
24
54
1100
36
<10
Silver
PPB
<5.0
<5.0
12
<5.0
<5.0
Aluminum
PPB
4400
660
13000
9400
3300
Iron
PPB
6300
710
2700
8500
4900
Manganese
PPB
12 0
12_0---_
5.7,11
16 0
12 0
Mercury
PPB
<0.2
'<:0.2y
(0.5)
<0.2
<0.2
II
* Grab sample taken for analysis.

Final effluent samples taken on June 22 and 24 contained 66 ppb and 54 ppb zinc, respectively. The N.C. Water
Quality Action Level for zinc is 50 ppb. Downstream concentrations of zinc were below the stated Action Level. Forty-
eight hour zinc LC50 values have been reported as low as 68 ppb for Daphnia magna and 76 ppb for Ceriodaphnia
reticulata3. EPA4 reported chronic toxicity values ranging from 47 to 852 ppb zinc for aquatic species. At the reported
concentrations in the effluent, zinc would be an unlikely contributor to receiving stream toxicity at 7010 conditions.
Influent levels of zinc were analyzed at less than 10 ppb on June 22 and 1100 ppb on June 24.
Nickel concentrations in the final effluent were 210 ppb and 200 ppb on the two sampling days. Downstream nickel
concentrations were 12 ppb and 11 ppb. At low flow stream conditions, these nickel levels would not exceed the N.C.
water quality standard of 88 ppb. However, these levels would be in excess of the EPA water quality criteria of 68 ppb (as a
24-hour average maximum) for the protection of freshwater species5. Nickel input to the facility varied considerably from
June 22 to June 24. Influent concentrations were 76 ppb and 1100 ppb, respectively.
On June 22, the final effluent contained 0.2 ppb mercury. The N.C. water quality standard for mercury is 0.012 ppb.
A chronic toxicity value of <0.23 ppb has been reported for mercury in a 30-day early life stage fathead minnow toxicity
test.6 Influent analysis detected 0.55 ppb mercury in the June 24 sample.
Manganese, aluminum, and iron were present in upstream, downstream, and dilution water samples at
concentrations which indicate a high ambient presence of these metals. Fluctuations of influent concentrations of these
metals were detected on the two sampling dates, as they were also noted for copper, zinc, nickel, and mercury. In
addition, silver and cadmium were detected in the June 24 influent sample. No silver or cadmium were present in effluent,
upstream, downstream, or dilution water samples for either sampling date. -
Total residual chlorine (TRC) levels were measured daily in the final effluent during the on -site evaluation. Chlorine
was monitored because of its potentially toxic instream effects. The following levels (ppm) of total residual chlorine were
recorded:
Date TRC
890619 <0.01 ppm
890620 0.01 ppm
890621 0.05 ppm
890622 <0.01 ppm
890623 0.03 ppm
890624 <0.01 ppm
The N.C. water quality Action Level for total residual chlorine is 0.017 ppm.
Composite samples of final effluent and influent were analyzed for the presence of organics, including pesticides,
and herbicides. Table 4 contains the results of these analyses and available toxicity data for those compounds. Traces of
I3-BHC and phenols were present in the effluent; however, they were at concentrations below those reported to cause
toxicity to aquatic organisms. It is not likely that these compounds were responsible for the_effluent toxicity observed. As
many as 13 organic compounds were detected in the effluent by GC/EC and GC/FPD. The concentrations of these

Table 4. Statesville Fourth Creek WWTP Organic Chemical Analyses with Available Toxicity Data.
Organic Analyses
Units
Sta. 02
Sta. 02
Sta. 02A
Toxicity Value
Test Type
Ref. #
890622
890624
890624
Effluent
Effluent
Influent
Q-BHC
PPB
0.02
Organics identified in influent only:
Total alkanes
PPB
180
Benzaldehyde
PPB
6
Butoxyethoxy ethanol
PPB
5
HCB
PPB
0.11
Trifluralin
PPB
0.21
LC50=19 ppb
48hr Bluegill
8
LC50=240 ppb
48hr Daphnia pulex
8
Unidentified peaks by GC/EC
#
11
12
26
Unidentified peaks by GC/FPC
#
1
1
2
Unidentified peaks by GC/MS
PPB
9
Unidentified peaks by GC/MS
PPB
57
i

compounds were not reported with the analyses. These unidentified organics could potentially be toxic to aquatic
organisms.
The facility is required by its NPDES permit to limit effluent concentrations of BOD, total suspended solids (TSS),
ammonia, DO, fecal coliform bacteria, chromium, and cyanide. On June 22, the effluent contained 150 ppm TSS. The
permit limit for TSS is 30 ppm as a monthly average and 45 ppm as a weekly average. Therefore, continued values such as
that of June 22 could lead to averages in excess of the permit limits. The other pollutants were within permitted maximum
values for both sampling dates.
The facility's Compliance Evaluation Analysis Report for the period from December 1988 to October 1989 revealed a
monthly TSS average concentration of 76.6 ppm in July, 1989. Reported values for the other months were below 30
ppm. However, the maximum daily value of TSS for the period of the report was 1,150 ppm. The chromium limit of 0.116
ppb was-ifxceeded in facility's effluent in December (40 ppb, monthly average) and April (17.25 ppb). The maximum
daily concentration of chromium for the period of the report was 69 ppb. Cyanide is limited to 0.014 ppm by the permit.
This limit was exceeded by the facility in February (0.016 ppm), and the overall maximum daily value reported was 0.03
ppm. The Compliance Report is contained in the Appendix.
BENTHIC MACROINVERTEBRATE ANALYSIS
Benthic macroinvertebrates were collected both above (Station 1) and below (Station 3) the Statesville Fourth Creek
WWTP with DEM's standardized qualitative sampling method. This method uses a wide variety of collection techniques to
inventory the aquatic fauna. The primary output is a species list with some indication of relative abundance (Rare,
Common, Abundant) for each taxon (see Apendix). Total taxa richness and the taxa richness of the most intolerant
invertebrate groups (Ephemeroptera, Plecoptera, Trichoptera) can be used with DEM criteria to assign water quality
ratings. Resulting bioclassifications are "Excellent," "Good," "Good/Fair," "Fair," and "Poor." Unstressed streams and
rivers have many species; polluted areas have fewer species. Water quality assessments also may use the abundance of
"pollution indicator" groups. Table 5 provides a physical description of the macroinvertebrate sampling stations used in
this analysis.
Three statistical indices were used with this data set to assign water quality ratings: the Wilcoxon Signed Rank
Statistic, a Common Taxa Index (CTI), and a Dominants in Common Index (DCI). The Wilcoxon test is a nonparametric
statistic which can be used to test the null hypothesis that no statistical difference exists between the total taxa richness of
the two sampling sites. It is based on a ranking of the differences in the number of species per order between the
upstream and downstream locations. The other two indices are based on Arkansas criteria7 and compare a downstream
site to an upstream control, producing ratings of "No Impact," "Slight Impact," "Moderate Impact," and "Severe Impact."
Both the DIC and the CTI look at the species which are found at both sites ("common" taxa) and vary from 0 to 100%. The
macroinvertebrate summary statistics for Fourth Creek are contained in Table 6. _
Biological samples taken above and below the WWTP discharge indicated that the facility had no effect on either
EPT taxa richness or total taxa richness of Fourth Creek. Using the EPT taxa richness criteria, Stations 1 and 3 received

Table 5. Physical Description of Macroinvertebrate Sampling Stations.
LOCATION
WIDTH (M)
DEPTH (M)
AVERAGE
MAXIMUM
CANOPY (%)
AUFWUCHS
BANK EROSION
SUBSTRATE(%)
BOULDER
RUBBLE
GRAVEL
SAND
SILT
COMMENTS
Statesville Fourth
01
Fourth Creek
SR 2316
Above WWTP
9M
0.8
1.5
40
Slight
Moderate
Trace
0
0
80
20
Creek WWTP Sampling
03
Fourth Creek
SR 2308
Below WWTP
9M
0.8
1.2
80
Moderate -Abundant
Severe
10
5
5
65
15
Stations
04
Fifth Creek
SR 2158
Dilution water
5M
0.3
0.7
70
Abundant
Severe
40
25
10
20
5
Turbid; recent rains would be expected to scour stream bottoms.
Table 6. Macroinvertebrate Summary Statistics.
Total Taxa Richness
EPT Taxa Richness
EPT Abundancet
Rating
Stations
01
59
18
89
Good/Fair
03
64
17
61
Good/Fair
Wilcoxon Signed Rank Test (P=0.01) No Significant Difference
Common Dominants Index 33% (Moderate Impact)
Common Taxa Index 52% (Slight Impact)
05*
25
111
Good
tAbundant=10, Common=3, Rare=1; summed for all EPT taxa.
*Abbreviated (4 sample) collection, limited to EPT taxa.

"Good/Fair" bioclassifications. Benthic community structural changes were evident between the two sites.
Ephemeroptera and Plecoptera were dominant at Station 1; Tricoptera (hydropsychids) and Oligochaeta (Limnodrilus
hoffmeisteri, especially) were dominant at Station 3. This change indicated the input of particulate organic matter (POM)
between the two sites. Hydropsychids feed on suspended POM, and Limnodrilus feed on deposited POM. In addition,
large numbers of Limnodrilus may be associated with low dissolved oxygen concentrations.
Several EPT taxa, as well as certain Coleoptera, declined in abundance at Station 3. The latter group can indicate
stress in a community under increased flow conditions, such as those present at the time of sampling. Riffle beetles,
which can withstand low dissolved oxygen conditions but are sensitive to toxics, were less abundant downstream.
The Wilcoxon Signed Rank Test did not reject the null hypothesis (no significant difference), indicating that there
was not a significant difference in taxa richness between the two sites. Results of the DCI and CTI tests detected
between -site differences. The Common Taxa Index was 52%, which represents a slight impact on Station 3. A moderate
impact (33% abundant taxa in common) was determined by the Common Dominants Index.
The benthic studies were conducted after a prolonged period of high flow in the receiving stream. The relatively
minor impacts that were observed in Fourth Creek due to the WWTP discharge suggest that, under low -flow conditions,
greater impacts might be expected.
CONCLUSIONS
The Statesville Fourth Creek WWTP effluent displayed acute toxicity caused a chronically toxic response in
Ceriodaphnia dubia at a concentration less than the instream waste concentration at low flow conditions. Two 48-hour
acute static toxicity tests performed on 24-hour composite samples of the effluent and influent resulted in LC50 values of
37% and 34%, respectively. The reproduction suppression test yielded a No Observed Effect Concentration (NOEC) on
mortality and reproduction of 10% and a Lowest Observed Effect Concentration (LOEC) of 25%, producing a Chronic
Value (ChV) of 15.8%. A 24-hour fathead minnow pass/fail acute toxicity test resulted in a "Pass" rating. Given the facility's
instream waste concentration of 36% during low flow conditions, both acute and chronic toxicity to cladocerans and
organisms of like or greater sensitivity would be expected in Fourth Creek.
Analyses of chemical samples show elevated effluent concentrations of copper, zinc, nickel, mercury, and TSS.
The metals were present in concentrations sufficient to be suspect as contributors of observed toxicity to Ceriodaphnia
dubia in the higher effluent concentrations. High, sporadic concentrations of copper, nickel, zinc, cadmium, silver, iron,
manganese, and mercury in the WWTP influent suggest pulse loading of metals. Therefore, metals which were not
detected by chemical analysis on June 22 and 24 could have been present in the effluent on other days and potentially
caused toxic effects.
Benthic macroinvertebrate population studies indicated that the discharge has had a significant impact on
downstream populations. Particulate organic loading might be partially responsible for this.impact, although the studies
indicate the likelihood of a toxic problem, also.

In a letter to the Mooresville Regional Office dated August 9, 1989, the facility reported the results of bench scale
tests it had been performing to detect sources of toxicity in its effluent. Metals levels were not being reduced by bench
scale reactor, but the WWTP stated that effluent nickel levels were decreasing over the past year. Possible Sewer Use
Ordinance violations by non -permitted industrial users were to be investigated. Toxicity characterization testing would not
be performed until the completion of plant expansion. As of January 17, 1990, the facility was not utilizing its expanded
facilities.
RECOMMENDATIONS
1. Steps should be taken to address the potential contribution of metals to the efflent's observed toxicity. Suggested
methods would include the EDTA metals chelation test described in: Mount, D.I. and L. Anderson -Carnahan. 1988.
Methods for Aquatic Toxicity Identification Evaluations: Phase I. Toxicity Characterization Procedures. EPA/600/3-88/034.
Sept 1988. Environmental Research Laboratory, Duluth, Minn. However, as this procedure can be used in the case of
acute toxicity only, further testing may need to include sampling and analysis of the concentrations of both total and
dissolved metals to correlate their concentrations with possible bioavailability.
2. Of the metal concentrations reported in the effluent, it is likely that mercury, zinc, and nickel would have the strongest
possible contributions to effluent toxicity. The continued presence of these metals, as well as others detected in the
effluent, should be investigated through a more intensive monitoring program including sampling of the effluent, influent,
and the receiving stream upstream and downstream of the discharge.
3. If the continued presence of metals in the influent and/or effluent is detected by the monitoring program described by
recommendation #2, then the facilities contributing to the treatment plant should be investigated to determine the
sources of these metals. Pretreatment options to eliminate or reduce metals received by the WWTP should then be
considered.
4. Mercury, zinc, and nickel limits should be considered for inclusion in the next issuance of the NPDES permit, pending
results of bench reactor testing and fractionation analyses.
5. The facility should continue to monitor total suspended solids in the effluent. Precautions should be taken to prevent
high concentrations of TSS from being released into Fourth Creek.
6. Due to continued failure to meet effluent toxicity limitations, the facility should be required to implement a formal toxicity
identification/reduction evaluation.

REFERENCES
1 U.S. Environmental Protection Agency. 1985. Short Term Methods for Estimating the Chronic Toxicity of
Effluents and Receiving Waters to Freshwater Organisms. EPA/600/4-85/014, 162 pp.
2U.S. Environmental Protection Agency. 1984. Ambient Water Quality Criteria for Copper. EPA/440/5-84/031.
3Mount, D.I. and T.J. Norberg. 1984. A seven-day life -cycle cladoceran toxicity test. Environ. Toxicol. Chem.,
3:425-434.
4U.S. Environmental Protection Agency. 1980. Ambient Water Quality Criteria for Zinc. EPA/440/5-80/079.
5U.S. Environmental Protection Agency. 1980. Ambient Water Quality Criteria for Nickel. EPA/440/5-80/060.
6CaII, Daniel J. et al. 1983. Toxicity and metabolism studies with EPA priority pollutants and related chemicals in
freshwater organisms. Wisconsin University -Superior Center for Lake Superior Environmental Studies. EPA-
600/3-83/095.
7Shackleford, B. 1987. Procedures for rapid bioassessments of aquatic macroinvertebrate communities. Arkansas
Dept. of Pollution Control and Ecology, Little Rock, Arkansas. 13 pp.
8Verschueren, Karel. 1983. Handbook of Environmental Data on Organic Chemicals, 2nd ed. Van Nostrand
Reinhold Co., New York. 1310 pp.

APPENDIX

96 Hour On -site Toxicity Evaluation Appendix
Aquatic Toxicology Group
N. C. Division of Environmental Management
For each on -site toxicity examination, a pre -test inspection of the facility site is performed in order to:
1) Determine appropriate areas for physical placement of the mobile laboratory.
2) Acquire proper equipment and installation needed for electrical service.
3) Determine appropriate areas for effluent sampling and equipment needed for such. Determine discharge schedule.
Sampling is done below chlorination unless otherwise specified.
4) Determine possible areas for dilution water collection (actual receiving waters or other unstressed streams in
the area) and equipment needed for such.
5) Collect additional samples of effluent and possible dilution waters for further static acute and static renewal
Ceriodaphnia dubia reproduction toxicity tests to determine the range of concentrations of effluent to be used for
the flowthrough toxicity test, to test for potential toxicity of' possible dilution waters, and for fish acclimation to
the chosen dilution water.
6) Determine route suitability to the facility for the mobile laboratory (eg. low clearances, poor road conditions).
7) Discuss test procedures and requirements with appropriate facility personnel.
8) Determine appropriate sampling sites and techniques for benthic macroinvertebrate surveys.
All test and sampling glassware and equipment are washed prior to use with soap and hot water, .then rinsed in
nitric acid, acetone, and distilled/deionized water to remove all toxins and contaminants. Upon actual arrival on -
site with the mobile laboratory, dilution water is obtained and dilution and effluent pumping systems are set up and
tested. Six to eight week old fathead minnows are wet transferred to the test chambers (containing approximately
one liter of dilution water), ten fish to a chamber.This transfer is accomplished five fish at a time in a randomized
order to each of the fourteen test chambers until two randomized sets of five have been transferred to each
chamber. Seven concentrations (with replicates) including a control are used. The second day on -site the dilutor
and the dilution and effluent pumping systems are turned on and the fathead minnow flowthrough toxicity test is
begun. A water bath is utilized to bring the effluent and dilution water to a constant 20 degrees centigrade. Test
organisms are fed newly hatched brine shrimp twice daily throughout the test.
A 7 day Ceriodaphnia dubia static renewal reproduction toxicity test using newborn organisms is begun the first
day on -site. The organisms are transferred to fresh dilution and effluent solutions daily and initial and final pH and
dissolved oxygen are recorded. The number of young born per organism per day is recorded and mean cumulative
reproduction is calculated for each concentration. The test is conducted at 25 degrees centigrade with a 16 light:8
dark hour photoperiod. Test organisms are fed 0.1 ml of a yeast/alfalfa/fermented trout chow mixture with
5.elenzatum capricornutum added per organism per day.(See Ceriodaphnia dubia Reproduction Toxicity Test
Appendix)
Individual chemical/physical parameter meters are calibrated daily according to DEM standards. At 15 minute
intervals throughout the test, Hydrolab systems measure and record dissolved oxygen, pH, temperature, and
specific conductance in the test chambers with the highest and lowest concentration of effluent. These systems are
calibrated at test initiation, mid -point, and termination. Data from these systems is recovered daily and stored on
floppy disc and hard copy. Daily residual chlorine measurements will be made of effluent, influent, dilution water,
and receiving stream samples as feasible.
During the on -site evaluation, Biological Monitoring Group personnel collect benthic macroinvertebrate samples at
the upstream, downstream, and dilution sites (see Benlhic Macroinverlebrate Survey appendix). Where
appropriate, electrofishing is undertaken upstream and downstream of the discharge to obtain resident fish
population data. On a site -specific basis, various other efforts are undertaken, such as monitoring dissolved
oxygen levels in the receiving stream.
On a daily basis, test chamber screens are cleaned, effluent and dilution pumping systems are checked and adjusted
as necessary, and pH, dissolved oxygen, and fish mortalities are recorded for each chamber. Dilution water is
generally collected on alternate days, depending on need. If the effluent has a high oxygen demand, aeration
systems for the test chambers are utilized and dissolved oxygen levels in the chambers are monitored closely in
order to prevent levels from dropping below 40% saturation at test temperatures.

Two separate 24 hour composite samples of effluent are collected for chemical analysis by means of an automatic
sampler. Influent, receiving stream, and dilution water samples are also taken for chemical testing.
Static 48 hour cladoceran toxicity tests are conducted on a 24 hour composite sample of the effluent and a grab
sample of the influent.
A Lour of the facility is conducted. The actual treatment process is reviewed to ascertain the quality of the
operation of the treatment system and to determine the treatment system's appropriateness to the type of waste
being treated. An inventory of any industrial contributors to a municipal waste treatment facility is made. The
manufacturing process at an industrial facility is reviewed to determine the nature and composition of the waste.
An inventory of all chemicals used at the facility in manufacturing or wastewater treatment is made. Where
feasible, 48 hour cladoceran static toxicity tests may be performed on samples from individual wastewater
streams coming into the wastewater treatment facility to attempt to pinpoint a particular source of toxicity.
A photographic record is made of the manufacturing and treatment facility, sampling points, receiving stream, and
sampling procedures.
At the end of the 96 hour test period, the dilutor is turned off and final mortality observations are made.
Breakdown and packing routines are performed and the mobile laboratory is transported back to the Cary Aquatic
Toxicology Laboratory. The Ceriodaphnia dubia reproduction toxicity test is continued al the lab until the 7th test
day.

Ceriodaphnia dubia Reproduction Toxicity Test Appendix
Aquatic Toxicology Group
N. C. Division of Environmental Management
The cladoceran Ceriodaphnia dubia is used as test organism in a 7 day static renewal toxicity test. This test
estimates the effect of an effluent or other water sample on reproduction. A control and 8 concentrations of
effluent ranging from 0.01 R to 100R are used. There are 10 organisms per concentration, each organism in a one
ounce polystyrene test chamber with 15 mis of solution. The test is conducted at 25 degrees centigrade with a 16
light/ 8 dark hour photoperiod.
All test and sampling glassware and equipment are washed with soap and hot water, then rinsed in nitric acid,
acetone, and distilled/deionized water, to remove all toxins and contaminants. Effluent samples are collected by
DEM Regional Office or Aquatic Toxicology personnel. All samples are collected chilled and below chlorination
unless otherwise specified. Each sample is collected as a grab or 24 hour composite using an automatic sampler and
is sent chilled to the Aquatic Toxicology Laboratory by state courier or bus. The sample must be received within
72 hours after collection.
The effluent samples are prepared for testing by being thoroughly mixed, adjusted to standard test temperature,
and aerated if dissolved oxygen is below 5 mg/l. Total residual chlorine is measured.
The test is initiated with organisms less than 24 hours old and within 4 hours of each other. The test is begun when
the neonates are introduced into the test chambers. Temperatures must be within 1 degree centigrade for transfer.
The organisms are transferred daily to new test chambers containing freshly mixed solutions. Dissolved oxygen,
pH, and temperature are measured twice for each batch of test solutions. The initial value is taken before the
organism is introduced and the final value after the organism has been transferred out the next day. The organisms
are fed daily. Each organism receives 0.1 ml of fermented trout chow -yeast -alfalfa food with Selenastrum
capricornutum added.
As reproduction begins, only the original test organism, now an adult, is transferred to the new chamber. A drop
of concentrated nitric acid is added to the old chamber. This kills the young so they can be easily counted under a
dissecting microscope. A mean number of young produced per adult is calculated for each concentration. Mortality
of greater than 20% in control test organisms invalidates a test.
Guidance Document:1985. U. S. E. P. A. Methods for estimating the chronic toxicity of effluents and receiving
waters to freshwater organisms. (EPA-600/4-85-014)

�KEX88/MP
COMPLIANCE EVALUATI�p �HALYJI� PFPnRT PA�E
. PERMIT--NC003i836 PIPE--O0i REPO|,�� PERlOB O0i2-3?ii L�`C---E
FACILITY-~%TATE%VILLE FOURTH CREEK WWTP DE�I�i/
LOCATION--%TATE%VILLE UH/COUNTY--03 lREDELL
5005O 003iO OO53O 0O6iO 3i6i6 �i��� O�3OO TcP3�
MONTH (3),/MGD ' BOD RE%/T%% NH3+NH4.... FEC COLl CHLORINE DO CERI7DPF
LIMIT F 4^0000 F 27.00 F 30.0 F iG.0O FNOL
88/12 2^1161 5.65 16.9
LIMIT F 4^0000^F 27.O0 F 301.O F 18F j- L
89/01 2^2741 6.7
89/�2 �^�2i4 6.92 25.9 .56 11.2
89/03 2.7193 6.96 23.0
LIMIT F 4^W0OO F i7.00 F 30.0 F
89/04 2^5966
89/05 3.1258 7.99
89/06 3^2466 7.60
`
89/07 3^4000 7.i2 76.�F .44 .155 8.54
89/08 3.2903 5.48 i4.4
89/09 3.0466 4.74
89/10 3^6483 6.34 ...
AVERAGE 2°9350 6.82 27.8
MAXIMUM i0.1000 46.60
MINIMUM 1^2000 2.0O ' 6.O LE%JTHAN LE�Jr(m/'
UNIT MCS, D ML M�/L MC,/L
`^`

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PAGE 2
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Benthic Macroinvertebrate Sampling Procedure Appendix
Biological Monitoring Group
N. C. Division of Environmental Management
Benthic macroinvertebrates, found on the bottom of streams, rivers, and lakes, are commonly used as
biological indicators of water quality. The Biological Monitoring Group uses a standardized qualitative
collection method designed to sample all habitats within a wadable stream and provide a reliable
estimate of both the number of different kinds of organisms (taxa) present and their relative abundance.
This data is then used to assign water quality ratings to the stream and river. This methodology is
applicable for most between -site and/or between date comparisons.
The sampling methodology requires that freshwater streams or rivers be wadable. High water
conditions severely impair sampling efficiency by making critical habitats inaccessible. Ten samples are
collected and processed at each site: two kick net samples from riffle and/or snag habitats; three
sweep net samples from bank, macrophyte, and root habitats; three fine -mesh samples from, rocks,
logs, and sand; one leaf pack sample collected in the current; and a visual inspection of large rocks and
logs. A collection card is filled out at each sampling station with relevant data on station location, field
parameters, instream habitat, and water chemistry.
Data output for the standard qualitative technique consists of a list of all taxa collected with a rough
estimate of abundance (Rare if 1-2 individuals are collected, Common for 3-9 individuals, or Abundant
for more than 9 individuals). The total number of taxa collected or total taxa richness (ST) and taxa
richness for the pollution intolerant groups Ephemeroptera, Plecoptera, and Trichoptera (SEPT) are
calculated for each sample. These values are used to assign a biological classification to each station
(Excellent, Good, Good/Fair, Fair, and Poor). Bioclassification criteria for several ecoregions have been
developed, including mountain, piedmont, inner coastal, and outer coastal. The "bioclassification" rating
primarily reflects the influence of chemical pollutants. The effects of sediments are poorly assessed by
taxa richness analysis.
An abbreviated version of this qualitative collection technique, the "EPT" survey, can be used to quickly
determine gross between -site differences in water quality. Collections focus on the pollution intolerant
groups within the benthic community: Ephemeroptera, Plecoptera, and Trichoptera. Only four samples
are processed: 1 kick, 1 sweep, 1 leaf -pack, and 1 visual. Field notes record extremely abundant taxa.
Data summary is usually limited to EPT taxa richness (SEAT) and EPT abundance (NEAT). Abundance
values are calculated using 1 for Rare species, 3 for Common species, and 10 for Abundant species.
These values are then summarized for all EPT taxa.

ORDER E SPECIES
APPENDIX 2 SPECIES LIST AND RELATIVE ABUNDANCE,
STATESVILLE THIRD CREEK WWTP (T) AND FOURTH CREEK WWTP (F )
IREDELL COUNTY, JUNE 1989.
STAT1O;4S
T1 T3 FL F3
EPHEMEROPTERA
BAETIS FLAVISTRIGA R R
BAETIS INTERCALARIS AAAA
BAETIS PLUTO RRRR
BAETIS PROPINQUUS ACAC
CAENIS SPP CCCC
CENTROPTILUM SPP C R C R
CLOEON SPP R R
DANNELLA SIMPLEX C C
HEXAGENIA SPP R C R L
ISONYCHIA SPP - AAAA
PSEUDOCLOEON SPP R R
STENONEMA MODESTUM AAAA
TRICORYTHODES SPP AAAA
PLECOPTERA
ISOPERLA TRANSMARINA (GR) R R
NEOPERLA SPP R R R
PARAGNETINA FUMOSA R `�
PERLESTA PLACIDA A A A 4
PTERONARCYS DORSATA R R
TRICHOPTERA
CHEUMATOPSYCHE SPP 4 A A A
HYDROPSYCHE BETTE`41 CCCC
HYDROPSYCHE ROSSI R R
HYDROPSYCHE SPARNA R R
HYDROPSYCHE VENULARIS 4 4 A A
LYPE DIVERSA R C R C
PYCNOPSYCHE GUTTIFER C C
TRIAENODES TARDA R R
COLEOPTERA
ANCYRONYX VARIEGATUS CCCC
DERONECTES GRISEOSTRIATUS R R
OINEUTES SPP P. R
DUBIRAPHIA QUADRINIJTATA R c
OUBIRAPHIA VITTATA R . R
HELICHUS SPP R q
HYDROPORUS SPP R ��
MACRONYCHUS GLABRATUS 4 C A C
DDUNA TA
ARGIA SPP R , R A
BOYERIA GRAFIANA C C
BOYERIA V INOS A C C A
CALOPTERYX SPP k ��
CORDULEGASTER SPP ,R
ENALLAGMA SPP k K
GOMPHUS SPP 4 C A C
MACROMIA SPP R R

ORDER E SPECIES
APPENDIX 1. SPECIES LIST AND RELATIVE ABUNDANCE,
STATESVILLE THIRD CREEK WWTP (T) AND FOURTH CREEK WWTP (F
IRE©`LL COUNTY, JUNE 1989.
STATIONS
T1 T3 FI F3
LIMNOORILUS HOFFMEISTERI R R
LIM1VODRILUS SPP R R
LUMBRICULIDAE A A
NAIS SPP RRRR
OP I STHOPORA SPP R R
CRUSTACEA .
ASELLUS 'SPP R R
CAMBARUS .SPP CCCC
r
MOLLUSCA.
CORB.ICULA MANILENSIS •- RRRR
ELIMIA SP R R
_ PHYS.ELLA SPP C C
S,TAGNICOLA R R
OTHER:
;: HYDRACARINA R R
PROSTOMA GRAECENS R R

List of Definitions
Aquatic Toxicology Group
N. C. Division of Environmental Management.
Acclimation - refers to the process of gradually adjusting organisms from water of one type to another so that the
organisms are not stressed from radical changes in temperature, hardness, pH, ionic strength, etc.
Acute toxicity - the effect a short term exposure to a chemical or substance has on an organism; usually defined as
death of that. organism.
Application factor - a value which estimates an instream toxicant level that will be safe at a chronic level for resident
organisms from acute toxicity data, usually defined by a fraction of the LC50.
Aquatic - having to do with water.
Aquatic Toxicology Group - the group within the Biological Services Unit (Water Quality Section) which performs
aquatic toxicity tests for the Division of Environmental Management. The Group is located at. the Cary
laboratory facilities. All test organisms (including Daphnia pulex, Ceriodaphnia sue., and fathead minnows) are
cultured at these facilities by Aquatic Toxicology personnel.
Benthos/Benthic macroinvertebrates - a wide assemblage of invertebrate animals (insects, crustaceans, molluscs,
etc.) which live in streams, are an important food source for fish populations, and are used as long term water
quality indicators.
Cadmium - one of the toxicants recommended by EPA for quality assurance testing of the health of aquatic organisms.
Calibration - the adjustment of meters or systems with standards of known values in order to assure the quality of
data obtained from these meters or systems.
Ceriodaphnia dubia - a small cladoceran crustacean. It is found throughout most of North America and obtains a
maximum size of approximately 1 mm. This organism has been adopted for aquatic toxicity testing because of
its small size, ease of culture under laboratory conditions, stability of genetic strains, and sensitivity to toxic
substances. It is generally used in a 7 day static renewal "mini -chronic" toxicity testing for mortality, time
to sexual maturity, and reproductive rate. Ceriodaphnia dubia is accepted in the field of aquatic toxicology for
testing in moderately soft waters.
Chronic toxicity - the effect of a chemical or substance on an organism, usually during a longer period of time than that
measured for acute toxicity. This effect is usually measured as a non -fatal response (eg. reduction in growth,
egg production, predator avoidance, feeding rate, etc.). Tests for chronic toxicity are frequently performed
during the entire life cycle of the organism.
Chronic value (ChV) - A numeric value representing the geometric mean of the numeric values of concentrations
analyzed as the No Oberserved Effect Concentration (N.O.E.C.) and the lowest Oberserved Effect. Concentration
(L.O.E.C.) by chronic toxicity testing. The chronic value is an estimate of the toxicant concentration that will
be the actual no effect concentration based on the chronic effect tested. ChV=Antilog((Log
Log 10N.O.E.C.)/2) .
Cladoceran - Commonly known as water fleas, the Order Cladocera belongs to the Class Crustacea which includes
shrimps and crabs. Cladocerans are capable of asexual reproduction and therefore create genetically similar
offspring easily cultured in the laboratory environment, making them ideal as test organisms. The cladocerans
are generally considered to be a freshwater species sensitive to the effects of toxicants.
Composite - a sample or method of sampling used to obtain data on a substance which may vary over Lime or space. For
example, a time or temporal composite of a stream would be one collected at intervals of time at the same
location. This is frequently accomplished with automatic sampling devices.
Daphnia puiex - a small cladoceran crustacean. it is found throughout most of North America and obtains a maximum
size of approximately 3.5 mm. This organism has been adopted for aquatic toxicity testing because of its small
size, ease of culture under laboratory conditions, stability of genetic strains, and sensitivity to toxic
substances. It is generally used in a 48 hour static toxicity testing for mortality. D. pulex is widely accepted
in the field of aquatic toxicology for testing in moderately soft waters.
Design flow (DF) - the volume of water and waste that is initially planned to pass through a facility or waste treatment
plant and still allow maximum operating efficiency. Design flow is usually expressed in millions of gallons per
day (rngd).
Dilution (water) - the water used in aquatic toxicity tests to dilute the waste water to various concentrations
(expressed as percent). Wherever possible, this water is from the actual stream that receives the waste,
upstream from that waste. When this is not possible, other suitable water is obtained.
Dilutor - refers to a modified Mount and rungs design serial dilution apparatus which receives dilution water and
effluent/waste and, through a series of chambers and electrical solenoid valves, mixes the effluent and
dilution into a series of concentrations for the test (expressed as percentages of 100% effluent).