NC0047597_Report_19860709

DIVISION OF ENVIRONMENTAL MANAGEMENT
July 9, 1986
MEMO RAND U M
TO:
George T. Everett
Dave Adkins
Dennis Ramsey
FROM: Steve W. Tedder
SUBJECT: Durham -Farrington Road WWTP Intensive Toxics Evaluation
NPDES No. NC0047597, Durham County
Staff of the Technical Services Branch have conducted intensive
toxics, biological and chemical evaluations at the Durham -Farrington
WWTP. This evaluation was conducted during October 1985.
The attached report details the results and conclusions, as well
as recommended actions. If there are questions, please contact Ken
Eagleson or myself at [phone] or Larry Ausley at [phone].
Attachment
SWT:ps
cc:
Ken Eagleson
Larry Ausley
Doug Finan
Jay Sauber
Meg Kerr
Jimmie Overton

Durham Farrington Rd_ WWTP
Toxicity Examination
NPDES#NC0047597
111111111111
Chhhhh1tTJ
111111111111
North Carolina Department of Natural
Resources & Community Development
MOBILE 1 i
Bioassay and Biomonitori ng
LABORA TORY
® 0
tt33 13 t2 3#' 3 V,# 332» ,T$31z3t4 ,;!3'3 32 ,"'"'" 3t 3M.:3t0...13#33t3333333'#
NORTH CAROLINA DEPARTMENT OF NATURAL
RESOURCES AND COMMUNITY
DEVELOPMENT
WATER QUALITY SECTION
June, 1986

DURHAM FARRINGTON ROAD WWTP
TOXICITY EXAMINATION
NPOES NO. NC0047597
NORTH CAROLINA DEPARTMENT OF NATURAL RESOURCES
AND COMMUNITY DEVELOPMENT
DIVISION OF ENVIRONMENTAL MANAGEMENT
WATER QUALITY SECTION
June 1986

TABLE OF CONTENTS
Page
List of Figures and Tables
Introduction 1
Toxicity Examination 2
Chemical Sampling 6
Benthic Macroinvertebrate Analyses 14
Conclusions 20
Recommendations 21
Footnotes 22
Appendix 23
Daphnia,pulex Test Procedure 24
96 Hour flow -Through Test Procedure 25
Ceriodaphnia Reproduction Test Procedure 27
Benthic Macroinvertebrate Procedure 28
List of Definitions 30

LIST OF TABLES
Page
Table 1. Industrial Contributors to Durham Farrington Road WWTP 1
Table 2. Durham Farrington Road Self -Monitoring Bioassay Results 4
Table 3. Chemistry Sampling Sites 10
Table 4. Chemical Analyses - Durham. Farrington Road WWTP 11
Table 5. Taxa Present in Major Benthic Groups - New Hope Creek,
Pokeberry Creek (Oct. 9, 1985); Third Fork Creek
(April 30, 1985) 15
Table 6. Benthic Taxa Collected from New Hope Creek and Pokeberry Creek
(April 30, 1985) 16
LIST OF FIGURES
Page
Figure 1. Schematic Diagram of Durham Farrington Road WWTP • 3
Figure 2. Seven -Day Ceriodaahnia Mortality 7
Figure 3. Seven -Day Ceriodaohnia Mean Cumulative Reproduction 8
Figure 4. Durham Farrington Road WWTP Study Area and Sampling Sites 13

Durham -Farrington Road WWTP
INTRODUCTION
An on -site toxicity examination was conducted at the Durham -Farrington Road
Wastewater Treatment Plant (NC0047597) from October 14-19, 1985. This facility,
located in Durham County, began operation in mid November of 1984. The Durham -
Farrington Road WWTP has a permitted flow of 10 million gallons per day (MGD) and
treats primarily domestic waste, but also receives industrial wastewater from
nearby commercial and industrial contributors. The industrial facilities con-
tribute approximately 34.5% of the facility's permitted flow. The individual
contributions of several major industries are presented in Table 1.
Table 1. Industrial Contributors to the Durham -Farrington Road WWTP
Industry
American Tobacco Co.
Flav-O-Rich, Inc.
Durham Linen Services
Pepsi -Cola Bottling Co.
Fairy Finishing Plant
Newton Instrument Co.
Pifer Industry
Piedmont Gravure
South Chem
Category
Cigarette Manufacturer
Milk Processing
Linen Supply
Soft Drink Manufacturer
Hosiery Mill
Electroplating
Electroplating
Electroplating
Industrial Organic Chemicals
Flow (gal/day)
295,000
74,000
52,000
37,000
20,000
15,000
7,000
2,000
2,000
All major industrial contributors had previously discharged their wastewater
to the Durham -Third Fork WWTP (NC0026298) with the exception of the Pepsi -Cola
Bottling facility, which discharged to the Durham -New Hope WWTP (NC0026280).
Both of these treatment plants have ceased discharge since the Durham -Farrington
Road WWTP began operation.
This document details findings of chemical and biological sampling, includ-
ing the following:
1.) 48 hour static bioassay using Daphnia pulex on effluent samples to
determine acute toxicity.

2.) 96 hour flow -through acute bioassay using Pimephalespromelas (fathead
minnows) performed on effluent collected prior to chlorination.
3.) Chemical samples collected from effluent, influent, and the receiving
stream.
4.) Collection and analysis of macroinvertebrate samples to determine the
impact of the effluent on the receiving stream populations.
5.) Seven-day Ceriodaphnia reproduction test to assess sub -lethal (chronic)
toxicity.
The Durham -Farrington Road WWTP discharges into New Hope Creek (Class C)-in
the Cape Fear River Basin. The 7010 (7 day, 10 year low flow) for New Hope Creek
is 0.1 cfs. The permitted flow of the facility is 10 MGD. During 7010 low
stream flow and permitted discharge flow conditions, the effluent from this
facility produces an instream waste concentration (IWC) of 99.35%. From November
1984 until April 1986 the facility has submitted eighteen (18) monthly self -
monitoring compliance reports. Results from these reports indicate permit viola-
tions in levels of BOD for 11 months, NH8 •for 9 months, and fecal coliform for 5
months. The average flow for the eighteen month period was 6.77 MGD.
The waste treatment processes include an influent trash rake, bar screens
and grit removal, primary settling with scum removal, aeration utilizing a fine
bubble diffuser, final clarification from four secondary clarifiers, chlorine
contact chambers, post aeration, and sludge drying beds. A schematic of the
Durham -Farrington Road WWTP appears in Figure 1.
TOXICITY EXAMINATION
An on -site toxicity examination was conducted at the Durham -Farrington Road
WWTP as a result of a series of four Daphnia pulex 48 hour static bioassays
performed by the Aquatic Toxicology Group. The test dates and resulting LCso
values of these tests were: 3/15/85 - 27%; 4/11/85 - P25; 6/6/85 - 52%; 10/2/85
- None. The LCso value is the concentration of effluent lethal to fifty percent
of the test organisms. A value of P25 indicates a partial mortality of 25% in

Figure 1. Schematic Diagram of Durham Farrington Road WWTP
Anaerobic Sledge Digestion
,6%
Bluer and lab building
1):1
Parshall fiuKe
Aerobic Sludge
Oeuatering
Aerobic Sludge Digester
Chlorine Building
Grit Reeceal Bar Screen
Statism 12
Sisussy Suplift, Pt.
Secondary
Clarifiers
J
Primary
Clarifiers
Aeration
Basins
Stitisa 121
Iafleest
Influent Lift Station
Chlorine
Contact
0
0
0
0
Trash Rakes
,CNN-,
'%'. ,
♦..N.'
, ♦ ♦ ♦
1 ♦ ♦ ♦ 1
1 \ N. 1
N. \ \ •
/ / / 4
/ / I /
I ed.,
/ Ore,
. / \ / \ J ♦r
1 ♦ ♦
♦!
% ♦ \ ♦
♦ ♦ ♦
, ♦ \ \
/ 1 1 .
/ / /
\ ♦ \ \ \
/ / / /
/ / /
♦ 1 ♦ 1
/ / / 1
,•
/ /
\ \ \ •
, 1 / I
, \ \ \
♦ \ \ \ \
1 1 1 \
♦ ♦ 1 •
/ / 1 J
. ♦ 1 \
/ / , ,
♦ ♦ % ♦ \
r / / /
♦ 1 1 1
. / / /
♦ ♦ 1
/ , I .4
\ / \ / ♦
/
/ / / /
♦ / ♦ ! ♦ / ♦/
/ / / /
\ / \ / ♦ / ♦
, / / /
/ ♦ / \/ ♦ /•
, \ \ \
\ ♦ \ ♦ \
1 1 1 1
1 1 1•
,, ,,,"
"'''-l.9
% 1
/ / / /
/1
% 1 % •
, / / /
' ''
.\1\�
/,,
'
%1 \\ .\%
/ / / /
, \ \ \
/ / , I
\ \ 1 1 1
1 / / /
♦ ♦ ♦ ♦
/ / / /
♦ \ 1 •
I 1 / /
, \ 1 ♦
1 1 ♦ 1 \
♦ ♦ 1 ♦
\ \ ♦ •
, ♦ 1 \
\ \ ♦ ♦ 1
♦ ♦ ♦ ♦
♦ 1 1 •
el.',
/ / 1 /
/ zee
, / / I
, ♦ ♦ \
/,, 4
\ 1 ♦ \ \
,,,/,,,,_,,,
1 ♦ ♦ \
\ \ ♦ •
, \ ♦ \
\ ♦ ♦ 1 \
♦ \ 1 1
\ ♦ 1 ,
, \ \ \
♦ 1 \ ♦ \
♦ \ ♦ ♦
♦ ♦ ♦ •
. ♦ ♦ ♦
♦ ♦ ♦ ♦ 1
1 ♦ \ ♦
♦ ♦ \ N
//1J
////.////
•///
. ♦ 1 \
♦ 1 \ ♦ \
♦ ♦ \ ♦
1 ♦ ♦ •
/ / / 11
/ / 1 /
/ / 1 /
/ / / /
—3—
Sludge Drying Beds

the highest effluent concentration tested (90%) and "none" indicates no signifi-
cant mortality at any effluent concentration.
On July 3, 1985, the N.C. Department of Natural Resources required the City
of Durham to initiate monthly self -monitoring bioassays to be performed using
Durham -Farrington Road WWTP effluent. This testing was begun in August of 1985.
A summary of that data appears in Table 2. The target acute toxicity value
(LC50) for these bioassays is >90%.
Table 2. Durham -Farrington Road Self -Monitoring Bioassay Results
Month Daphnia pulex 48 hr. LC60
August 1985 28
September 1985 27.5
October 1985 64*
December 1985 10
February•1986 >90
March 1986 90
April 1986 - 56
June 1986 80
* Performed by N.C. DEM Aquatic Toxicology Group. All others were per-
formed by Black & Veatch, Inc.
On -site bioassays were performed from October 15-19, 1985 and included a 96
hour. flow -through bioassay using fathead minnows (Pimephales promelas) as the
test species, Daphniaoulex 48 hour static bioassays, and a seven-day Ceriodaoh-,
nia chronic toxicity bioassay measuring both lethality and reproduction suppres-
sion. Dilution water for these on -site tests was obtained from Pokeberry Creek
at SR-1711 in Chatham County, N.C. This water was tested prior to use at the
Aquatic Toxicology Laboratory using the Ceriodaphnia reproduction test. Repro-
duction in this dilution water was similar to that of laboratory culture water.
The 96 hour flow -through bioassay was performed on effluent collected from
the overflow weirs of two final clarifiers prior to chlorination. The effluent
and dilution delivery pumps were turned off for four hours by way of timers dur-
ing the early morning hours due to extremely low effluent flows during those
—4—

hours. The test organisms (fathead minnows) were 35-40 days old at the beginning
of the test and were obtained from cultures at the Aquatic Toxicology Laboratory.
These minnows were acclimated to the dilution water 72 hours prior to test ini-
tiation. At approximately 17.5 hours prior to test initiation, the minnows were
randomly transferred to each test chamber. The percentages of effluent to which
the minnows were exposed were 0 (dilution water), 5, 10, 25, 50, 75 and 100.
These dilutions of effluent were tested in replicate. Each test chamber contained
10 minnows. The bioassay was initiated at 10:05 AM on October 15, 1985 and ter-
minated at 10:05 AM on October 19, 1985. The toxicant delivery system cycled 488
times over the 96 hour test period, yielding a 90% replacement volume of test
solution every 2.5 hours. There were no mortalities recorded during the test
period.
Daphnia pulex 48 hour static bioassays were conducted while on -site using a
24 hour composite effluent sample of the effluent and an instantaneous -grab
sample of the influent. The resulting LCee's of (5% for the influent test and
64% for the effluent test indicate that there is significant, but incomplete
removal of toxicity by the treatment plant.
A seven-day Ceriodaphnia static replacement bioassay was performed on dilu-
tions of effluent to assess both sub -lethal toxicity and lethal chronic toxicity.
This test was initiated on -site on October 14, 1985 and terminated at the Aquatic
Toxicology Laboratory on October 21, 1985. A 168 hour LC.0 value of 18% was cal-
culated based on mortality results. The semi -logarithmic graph used to determine
this value is depicted in Figure 2. Reproduction similar to that of the controls
was recorded for all concentrations through 10%. Mean cumulative reproduction is
depicted in Figure 3. It should be stressed that lethality is a more sensitive
indicator of chronic toxicity than reproduction suppression of surviving females
in this instance. Using lethality as the chronic toxicity indicator, a chronic
value (ChV) of 15.8% is calculated from this data.

CHEMICAL SAMPLING
A series of chemical samples was collected during this evaluation and sent
to the Division of Environmental Management Chemistry Laboratory for analysis. A
description of the sampling stations is found in Table 3. All samples were col-
lected as instantaneous grabs with the exception of Station 02 samples (effluent
bioassay sampling point) which were taken as 24 hour composites. Figure 4, a map
of the study area, illustrates sampling site locations. Results and summaries of
chemical analyses are documented in Table 4. Metals analyses of Durham -Farring-
ton Road WWTP effluent revealed elevated levels of zinc. It was reported at 110
ppb on October 17 and 90 ppb on October 19. Zinc LCee's have been reported as
low as 100 ppb in 48 hour Daphnia, pulex bioassays at a hardness of 10-80 mg/I'.
Zinc was detected in samples downstream of the discharge (Station 03) at 60 ppb on
October 17 and..80 ppb on October 19. Both of these values exceed the N.C. Water
Ouality Standards Action Level of 50 ppb. Zinc was not detected at the upstream
sampling station (Station 01) on either sampling date.
Cyanide was detected in the effluent on October 17 at 0.03 ppm and at the
downstream sampling station at 0.04 ppm. This last value exceeds the N.C. Water
Quality Standard of 0.004 ppm for cyanide. LCeo's for cyanide have been measured
as. low as .083 ppm in a 48 hour Daphniapulex static bioassays. At levels of
0.02 and 0.03 ppm, cyanide has reduced growth in rainbow trout by 40 to 95%a.
Organic chemistry analyses of an effluent composite sample taken October 17
detected lindane at 0.43 ppb, trichloroethane at 1.8 ppb, dibutyl phthalate at
3.3 ppb and diazinon at 0.28 ppb. On October 19th, analyses performed on a com-
posite sample taken from this same station revealed lindane at 0.64 ppb, tetrach-
Ioroethene at 0.09 ppb and trichloroethane at 0.46 ppb. Organics analyses also
detected an unidentified organic compound in the effluent sample from October 17
and 2 unidentified compounds in the effluent sample from October 19. Lindane was
detected at 0.64 ppb in a grab sample taken from the downstream station (Station

Figure 2. Seven Day Ceri odaphn i a Mortality
T
0
X
C
A
N
T
V
0
L
u
M
E
100
10
1
LOG -CONCENTRATION VS % MORTALITY
0 10 20 30 40 50 60
R MORTALITY
LC50 =18%
70
80
90 100

Figure 3. Seven Day Ceriodaphnia Mean Cumulative Reproduction of Surviving Females
Mean Young
Produced
25
20
15 ...
10
5
0
3
4
5
Day of Test
10014 Mortality was
recorded in the 50-100X
effluent concentrations
with no reproduction.
6
7
Durham Farrington Road WWTP
—8—

03) on October 19. This value exceeds the N.C. water quality standard for lin-
dane of 0.01 ppb. Chloroform was also detected at this station at a level of 6.3
ppb. Organic analyses performed on the influent (Station 02A) detected 1.7 ppb
of trichloroethene, 0.18 ppb of tetrachloroethane and 4 unidentified compounds in
the sample from October 17. Analysis of the sample from October 19 revealed lin-
dane at 0.64 ppb. Tetrachloroethene, trichloroethane, and diazinon are listed
among "Chemical 'Substances Requiring Special Attention" in the N.C. Water
Quality Standards. Diazinon, with reported 48 hour Daphnia pulex,ECso's.of 0.8
ppb4 and 0.9 ppb is a likely contributor to the acute toxicity seen in the D.
pulex static bioassays and most certainly is a contributor to the chronic mortal-
ity in the Ceriodaphnia life cycle test. Diazinon is used on a wide variety of
agricultural crops, ornamentals, domestic animals, lawns and gardens, and house-
hold pets. Lindane, with a 96 hour bluegill sunfish LC5O of 57 ppbs, and a 48
hour Daphnia pulex ECao of 460 ppbT could be a marginal contributor to chronic
toxicity at the levels detected. Toxicity data for tetrachloroethene include a 96
hour fathead minnow flow -through LCso's of 13,400 ppb and 18,400 ppb•. These
values are 150,000 to 200,000 times greater than the amounts of tetrachloroethene
found in Durham Farrington effluent. Fathead minnow 96 hour flow -through LCso's
of 81,600 ppb'o and 52,800 ppb" have been reported for trichloroethane. These
amounts are 114,000 to 170,000 times greater than the levels of trichloroethane
found in the effluent. Tetrachloroethene and trichloroethane were present in the
effluent in amounts well below levels known to cause the toxic effects seen in
the bioassays performed in this study. Limited toxicity data on chloroform indi-
cates that the amounts found downstream (6.3 ppb) would most likely not produce
acutely toxic conditions. A 48 hour Daphnia manna LCso of 29,000 ppb has been
reported for chloroform's.

Table 3. Chemistry Sampling Sites
Station 01 - New Hope Cr. just upstream of an 1-40 bridge construction site and
approximately 1500 m upstream of the Durham -Farrington Road WWTP
discharge. At this point the creek is approximately 10 m wide.
Station 02 - Durham Farrington Road WWTP effluent at the overflow weirs of sec-
ondary clarifiers 41's 1 & 2 (see Figure 1) This is the bioassay
sampling point for the Daphnia oulex static tests.
Station 02A - Durham Farrington Road influent, just prior to the influent bar
screen.
Station 028 - Durham -Farrington Road chlorinated effluent at the spillway from
the chlorine contact chamber.
Station 03 - New Hope Creek at SR-1107 approximately 1500 m downstream of the
Durham -Farrington Road WWTP discharge. At this point the creek is
approximately 15 m wide.
Station 04 - Pokeberry Creek at SR-1711. Here the creek is approximately 5 m
wide. This was the dilution source for all bioassays connected
with this study.

Table 4. Chemical Armlyss-aa Farrington Rd. WITP
Permitted Flow (1160)
10
Average Stream F l ow (CFS)
78
7Q10 (CFS)
0.1
. Chemical/Physical
Units
Mater Qual.
Sta 01
Sta 02
Sta 02A
Sta 02B
Sta 03
Sta 04
Ana l yses
Standards
851017
851017
851017
851017
851017
851017
BOD
PPN
1.7
6.5
75
2.8
0.9
COO
PPt
18
32
230
28
13
Coliform: MF Fecal
1 /100
110
36000
400000
180
Coliform: Tube Fecal
/100
13
Residue TOTAL
PPt1
170
320
340
270
160
volatile
PPM
33
737
120
56
38
fixed
PPt1
140
240
220
220
120
Residue SUSPENDED
PPM
4
5
110
7
2
volatile
PPN
2
5
86
2
1
fixed
PPM
2
0�
22
5
1
pH (standard units)
6.0-9.0
7
6.7
6.9
6.9
6.6
Acidity
PPM
9
30
31
14
12
Alkalinity
PPH
50
55
100
41`
49
Arsenic
PPM
<10
Cyanide
PPM
0.005
0.03
<0.1
Formaldehyde
PPM
<0.1
Hardness
PPM
55
32
42
44
36
Pheno l s
PPt1
<5
<5
13
<5
<5
Specific Conductivity
ullhos/cm
230
420
350
190
570
NH3PPM
0.06
1.9
"17
0.57
0.05
TKN
PPI1
i
0.4
8.7
55
1.6
0.2
NO2,NO3 _
PPM
0.01
6.8
0.03
5.9
0.13
P. total
PPt1
0.16
5.1
5.3
3
0.24
Aluminum
PPB
<100
<100
300
200
<100
Cadmium
PPB
2
<20
<20
<20
<20
<20
Chromium
PPB
50
<50
<50
<50
<50
<50
Copper
PPB
15(AL )t
<20
<20
50
<20
<20
Iron ,
PPB
1000
800
100
3000
_
400
600
Mercury
PPB
0.2
<0.2
<0.2
0.4
<0.2
<0.2
Manganese
PPB
120
110
300
160
<50
N i cke l
PPB
50
<100
<100
<100
_
<100
<100
Lead
PPB
25
<100
< 100
<100_
<100
<100
Zinc
PPB
50(AL)
<20
110
180
`
60
<20
Tributyltin Hydride
PPB
0.008
<0.03
<0.03
Mass Spec. Unidentified Peaks
*
2
1
4
Lindane _
PPB
0.01
0.43
Tetrachloroethene
PPB
0.18
Trichloroethane
PPB
I
1.8
1.9
Dibutyl Phthalate
PPB
,
3.3
Diazinon
PPB
0.28,
It Va 1 ues represent action 1 ere 1 s as specified in . 0211
Cb )(4)
Standards (
i
Fresh (later Classifications

Tab I e 4 . Chem i ca I Ana 1 j a5-Durho. Farrington Rd. UUTP
Permitted Flow (MGD)
10
.
Average Stream Flow (CFS)
78
7Q10 (CFS)
0.2
Chem i ca i /Phut. s i ca I
Units
Sta 01
Sta 02
Sta 02A
Sta 03
Sta 04
Predicted stream
Ana l yses
851019
_
851019
851019
851019
851019
conc. at 7010**
BOO
PPM
COD
PPM
27
35
510
32
15
Co l i form : I'1F Fecal
/ 100
Coliform: Tube Fecal
/100
Residue TOTAL
PPM
200
320
460
300
160
vo l at i l e
PPM
59'
70
210
58
33
fixed
PPM
140
250
250
240
130
Residue SUSPENDED
PPM
3b
3
350
5
1
volatile
PPM
2
3
290
1
1
fixed
PPM
1
0
63
4
0
pH (standard units)
7.1
6.9
6.9
7.1
6.8
Acidity
PPM
14
26
35
25
10
Alkalinity
PPI1
47
85
120
58
46
Arsenic
PPM
<10
<10
Cyanide
PPM-
<.01
<.01
0.04
0.0298
Formaldehyde
PPM
<0.1
<0.1
His
PPM
56
38
43
42
38
Phenols •-
PPM t
52
<5
Specific Conductivity
41hos/cm
280
460
620
470
140
N113
PPM
0.03
6.7
19
4.8
<.01
4.2721
TKH
PPM
0.3
7.4
31
7.7
0.2
7.9977
H02,H03
PPI1
0.02
2.9
0.03
3.9
0.08
4.8185
P. total
PPM
0.18
2.7
6.5
3
0.26
3.8747
A l um i num
PPB
<100
100
700
<100
<100
99.35
Cadmium
PPB
<20
<20
<20
<20
<20
<20
Chromium
PPB
<50
<50
<50
<50
<50
<50
Copper
P138
<20
<20
60
<20
<20
<20
Iron
PPB
1000
<100
2500
400
600
99.3500
Mercury
PPS
<0.2
<0.2
0.3
<0.2
<0.2
<.02
Manganese
PPB
290
110
260
140
<50
109.2850
Nickel
'Lead
PPB
<100
<1007
<100
<100
<100
<100
PPB
<100
<100
<100
<100
<100
<100
Zinc
PPB
<20,
90
180
80
<20
99.3500
Tributyltin Hydride
PPB
<0.03
<0.03
<0.03
<0.03
<.03
(lass Spec. Unidentified Peaks
*
2
,
Lindane
PPB
0.64
0.64
0.64
0.5315
Tetrachloroethene
PPB
0.09
0.0894
Trichloroethane
PPB
0.46
'
1.1227
Ch 1 oroform
PPB
6.3
** Values represent predicted instreae concentrations using average
effluent
concentrations and assuming am concentrations of 0 .
istr
1 i I 1 I

Figure 4. Durham Farrington Rd. WWTP Study Area and Sampling Sites

BENTH1C MACROINVERTEBRATE ANALYSIS
New Hope and Pokeberry Creeks were sampled for benthic macroinvertebrates on
October 9, 1985. These sites correspond to chemical sampling stations on New
Hope Creek above (01) and below (03) the Durham -Farrington Road discharge and the
bioassay dilution water collection site on Pokeberry Creek (04), respectively.
Data from this benthic investigation are summarized in Table 5 and all taxa col-
lected are listed in Table 6.
Benthic macroinvertebrates were sampled using a standardized qualitative
collection technique (DEM 1983). The primary output from this collection tech-
nique is a tabulation of taxa richness, i.e., the number of different kinds of
animals present. Unstressed streams and rivers always have high taxa richness.
Various types of pollution will reduce or eliminate the more intolerant species,
producing lower taxa richness values. In-house criteria have been developed to
relate taxa richness to five water quality ratings or bioclassifications: Excel-
lent, Good, Good/Fair, Fair and Poor. Taxa richness values are calculated both
for all species (ST) and for the more intolerant groups (Ephemeroptera, Plecop-
tera, Trichoptera: SEPT). The distribution and abundance of various pollution
"indicator" species also can be utilized to deduce changes in water quality.
Pokeberry Creek, Station 04, was given a bioclassification of Good. Total
taxa richness (ST) at this site was 86 and the EPT (intolerant) taxa richness
(SEAT) was 21. The stream was 4 meters wide with a substrate of boulder and
rubble in riffle areas and gravel and sand in pools.
Station 01, New Hope Creek above the WWTP, was 4 meters wide with a sub-
strate of silt and clay with some riprap along the banks, and several fallen
trees or "snags". Taxa richness values of 49/10 (ST/SepT) give this site a
bioclassification of Fair. Most taxa collected were tolerant to pollutants.
Examples are the mayflies Stenacron interounctatum and Baetis intercalarus; the
caddisflies Cheumatonsvche and Hvdrontila; and the very tolerant chironomids
-14-

Table 5.
Taxa Present in Major Benthic Groups
New Hope Creek, Pokeberry Creek (9 Oct 85) , Third Fork Creek (30 April 85)
New Hope Creek
Above Below Third Fork Pokeberry
Taxonomic Group
Ephemeroptera 7 5 2 10
Plecoptera 0 0 0 2
Trichoptera 3 0 1 9
Oligochaeta 3 2 5 5
0donata 7 4 0 10
Coleoptera 3 1 4 10
Megaloptera 1 0 0 3
Crustacea 4 2 4 2
Diptera (Misc.) 1 0 6 6
Ch i ronomi dae 15 15 14 18
Mollusca 2 2 1 6
Other 3 1 3 5
Total 49 32 40 86
EPT 10 5 3 21
Rating Fair Poor Poor Good

Table 6. Benthic Taxa Collected from New Hope Creek and Pokeberry Creek
October 9, 1985.
New Hope Creek
Above Below Pokeberry Cr.
EPHEMEKOPTERA
Baetis flavistriga - - A
Baetis intercalaris A R -
Baetis propinquus - - C
Baetisca carolina - - C
Baetisca gibbera - - R
Caenis C A -
Centroptilum C - -
Cloeon R - R
Epeorus rubidus - - R
Eurylophella temporalis R R -
Heptagenia marginalis - - R
Isonychia - - A
Paraleptophlebia R R -
Stenacron interpunctatum A C A
Stenonema modestum - - A
PLECOPTERA
Eccoptura xanthenes - - R
Sweltsa - - C
TRICHOPTERA
Ceraclea ancylus - - C
Cheumatopsyche A - A
Chimarra - - A
Hydropsyche betteni - - C
Hydropsyche venularis - - R
Hydroptila A - -
Oecetis - - R
Polycentropus R - R
Ptilostomis - - R
Triaenodes tardus - - C
OLIGOCHAETA
Branchiura sowerbyi - A -
Ilyodrilus templetoni R - R
Limnodrilus hoffmeisteri C - C
Lumbriculidae - - R
Opisthopora C - -
Quistadrilus multisetosus - - R
Stylaria lacustris - - R
Tubificidae - R -
ODONATA
Argia C A A
Basiaeschna janata - - R
Boyeria vinosa R - C
Calopteryx R - A
Enallagma C A C
Gomphus - - A
Hagenius brevistylus - - R
Macromia C - A
Nasiaeschna pentacantha - R -
Neurocordulia obsoleta - - C
Progomphus obscurus - - R
Sympetrum R R -
Somatochlora R - -
-16-

Table 6. (Cont.)
COLEOPTERA
Ancyronyx variegatus - - A
Berosus - - R
Deronectes - - R
Dineutus C - C
Dubiraphia vittata - - A
Helichus - - C
Hydroporus C R R
Macronychus glabratus - - A
Optioservus ovalis - - R
Psephenus herricki - - A
Sperchopsis tessalatus R -
MEGALOPTERA
Corydalus cornutus - - A
Nigronia serricornis - - A
Sialis C - A
CRUSTACEA
Asellus C A
Cambarus R R R
Crangonyx - - C
Hyallela azteca A
Palaemonetes paludosus R - -
DIPTERA (MISC. )
Anopheles - - R
Chrysops R - R
Hexatoma - - R
Palpomyia group - - R
Simulium (Phosterodorus) - - A
Tipula - - A
CFIIRONOMIDAE
Ablabesmyia mallochi A A A
Brillia R - R
Chironomus A R A
Conchapelopia A A -
Corynoneura - - R
Cricotopus A C
Cryptochironomus fulva R R R
Dicrotendipes neomodestus A C -
Labrundinia pilosella C - R
Nanocladius R - R
Paracladopelma undine - R -
Phaenopsectra flavipes C C -
Polypedilum fallax C A -
P. illinoense A C -
P. convictum - C A
Procladius C C R
Paratendipes - - C
Rheocricotopus C - C
Rheotanytarsus - - A
Stenochironomus C C C
Tanytarsus - C A
Thienemaniella - R C
Tribelos - A A
Zavrelimyia - - R
New Hope Creek
Above Below Pokeberry Cr.
-17-

Table 6. (Cont.)
New Hope Creek
Above Below Pokeberry Cr.
OTHER
Dugesia tigrina -
Erpobdella
Hydracarinidae
Placobdella papillifera R
Prostoma graecens -
Ranatra R
Sigara A
C
R
C
R
R

Chironomus, Dicrotendeaes neomodestus and Polvaedilum illinoense, all abundant at
Station 01.
Station 03, New Hope Creek below the WWTP, was rated Poor based on taxa
richness values of 32/5 (ST/SEpT). The abundance values of non-chironomid taxa
were reduced over those at Station 01. It was very unusual that no caddisfly
nymphs were collected at this site. Poor habitat and reduced flow could reduce
(caddisfly) CheumatoDvche abundance, but should not eliminate them entirely.
Both these observations could indicate toxics. The mayfly ,Coenis, the odonates
Araia and Enallaama, and the isopod Asellus were abundant.
It is not possible to determine whether the water quality degradation from
Fair at Station 01 to Poor at Station 03 is due to the Farrington Road WWTP or to
the effects of Third Fork Creek which enters New Hope Creek just above the Far-
rington Road discharge. A biological survey of Third Fork Creek in April 1985
showed Poor water quality with taxa richness values similar to Station 03
(ST=40, SEpT=3). At present there are no permitted dischargers on Third Fork
Creek. However, Durham -Third Fork WWTP and Durham -Hope Valley WWTP did discharge
to Third Fork Creek until late 1984 when the Farrington Road WWTP came on line.
If either of the WWTP's had impacted either stream, recovery might not be com-
plete. In addition, Third Fork Creek's drainage area includes a large portion of
the City of Durham and therefore, receives substantial urban runoff. The water
quality degradation in New Hope Creek below the Durham -Farrington Road WWTP could
be caused by the WWTP discharge or by urban runoff and/or residual water quality
problems associated with the now closed WWTP's on Third Fork Creek.

CONCLUSIONS
Results of on -site toxicological evaluations would predict an acutely toxic
effect to the biota of New Hope Creek from the Durham -Farrington Road WWTP dis-
charge at most stream flow regimes. This effect would become more pronounced
during lower flow conditions when the instream waste concentration (IWC)
approaches 99.35%. Given the 168 hour LC60 of 18% determined from the Ceriodaph-
nia Life Cycle Test, chronic toxicity expressed as mortality would be expected in
New Hope Creek during stream flows well above 7010 condiditions, including at
average stream flows when the IWC is equal to 16.6%.
Four chemicals found in the effluent and downstream of the plant discharge
are of particular concern. Cyanide and the pesticide lindane were detected
downstream of the plant discharge at levels exceeding N.C. water quality stan-
dards. Zinc was found downstream in amounts exceeding N.C. water quality action
levels. Diazinon was found in acutely toxic amounts in the effluent. Self -
monitoring data from this facility indicates that the action level for zinc and
the Water Quality Standard for mercury will frequently be exceeded.
The amounts of zinc and diazinon present in the effluent could account for
mortality in the Ceriodaphnia life cycle and Daphnia pulex bioassays. Possibly
lindane, and very likely cyanide, could be additional contributors to chronic
toxicity in the Ceriodaphnia life cycle test.
Benthic macroinvertebrate data indicate a decline in water quality down-
stream of the Durham -Farrington Road WWTP discharge, though this decline cannot
be solely attributed to the plant due to the complicating factors of Third Fork
Creek and extensive construction in the area.

RECOMMENDATIONS
1.) Durham -Farrington Road WWTP should continue to perform self -monitoring acute
toxicity tests until the )90% LC6O target level has been achieved consis-
tently, at which time the facility should be required to perform the
Pass/Fail Ceriodaohnia reproduction bioassay. This test should be performed
monthly until such time as the effluent passes the test for three consecu-
tive months. Should chronic toxicity target values under this test not be
met within six months. it is recommended that Durham -Farrington Road WWTP's
permit be reopened and a toxicity limit added. This toxicity limit should
be based on the facility's IWC at 7010 (99.35%) and should be defined as
quarterly Ceriodaohnia survival and reproduction tests.
2.) Efforts should be made by the plant to locate sources of zinc, cyanide, lin-
dane and diazinon. The facility should take appropriate actions to reduce
discharge of these chemicals to levels below N.C. water quality standards
and action levels.
3.) Zinc, cyanide, diazinon and lindane should be included as monitoring
requirements in the next Durham -Farrington Road WWTP NPDES permit issuance.

FOOTNOTES
Ambient Water Quality Criteria for Zinc, (USEPA. 1980), EPA 440/5-80-079.
a Ambient, Water QualityCriterua for Cyanide, (USEPA, 1985), EPA 440/5-85-028.
• D. George Dixon and Gerard Leduc, "Chronic Cyanide Poisoning of Rainbow Trout
and Its Effects on Growth, Respiration, and Liver Histopathology", Archives
of Environmental Contamination and Toxicology, 10 (1981), pp 117-131.
'' Waynon W. Johnson and Mack T. Finley, Handbook of Acute Toxicity of Chemicals
to Fish and Aquatic Invertebrates (United States Department of the Interior,
Fish and Wildlife Service, Washington, D.C., 1980), p. 26.
6 Sanders, H.O. and Cope, O.B., "Toxicities of Several Pesticides to Two Species
of Cladocerans", Trans. Am. Fish Soc., 95(2), pp. 165-169.
o W.F. Randall et al., "Acute Toxicity of Dechlorinated DDT, Chlordane and
Lindane to Bluegill (Lepomis macrochirus) and Daphnia manna", Bull. Environ.
Contam. Toxicol., 21, pp. 849-854, 1979.
' Sanders, H:O. and Cope, 0_B_, ,off cit., pp. 165-169.
o D.L. Geiger, C.E. Northcott, D.J. Call, and L.T. Brooke, Editois. Acute
Toxicities of Organic Chemicals to Fathead Minnows (Pimephalespromelas)
(Center for Lake Superior Environmental Studies, University of Wisconsin -
Superior, 1985), II, p. 26.
O Alexander, H.C., et al., "Toxicity of perchloroethylene, trichloroethylene,
1,1,1-trichloroethane, and methylene chloride to fathead minnows". Bull.
Environ. Contam. Toxicol., 20, 344, 1978.
1O D.L. Geiger, et al., aja. cit., p. 40.
11
Konemann, W.H., "Quantitative Structure -activity relationships for kinetics
and toxicity of aquatic pollutants and their mixtures in fish", Univ. Utrecht,
Netherlands, 1979.
12 G.A. Leblanc, "Acute Toxicity of Priority Pollutants to Water Flea (Daphnia,
maona), Bull. Environ. Contam. Toxicol., 24(5), pp. 684-691, 1980.

APPEND I X

48 Hour Daphnia pulex Screening Bioassay
Aquatic Toxicology Group
N. C. Division of Environmental Management
The Aquatic Toxicology Group performs 48 hour static bioassays using the c l adoceran
Daphnia pulex to estimate the toxicity of waste discharge to aquatic life in receiving
streams. 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 above
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 24 hours
after collection.
The samples are prepared for testing by being thouroughly mixed, adjusted to
standard test temperature, and aerated if dissolved oxygen is below 40% saturation.
Chlorine is removed with Sodium Thiosulfate if applicable. Initial pH and DO are
also recorded. The effluent is then diluted with D. pulex culture water, typically to
seven concentrations (with replicates) from 0 to 90% effluent. Each test chamber
receives 100.mis total volume and ten 24 hour old D. pulex test organisms. The test
is conducted in a 20 degree centigrade incubator with a 14:10 hour light:dark cycle.
Mortality of the D. pulex is recorded after 48-hours, along with final pH and
dissolved oxygen.
A 48 hour LC50, or concentration of effluent lethal to 50% of the test organisms in
48 hours, is calculated from the mortality data. An instream waste concentration
(IWC) for the effluent in the receiving stream is calculated using the treatment
system design flow and low —flow (7Q10) stream flow. The LC50 and IWC are then
used to predict instream toxicity. If the effluent toxicity and/or the IWC are high. a
persistance bioassay may be conducted. This involves a second 48 hour static D. pulex
bioassay on the same effluent sample after it has been exposed to light and aeration
for an additional 48 hours. 1f there is a 100% reduction in the LC5g, the effluent is
considered to be non—pers istant.

96 Hour On —site F l owthrough Bioassay
Aquatic Toxicology Group
N. C. Division of Environmental Management
Candidacy for an on —site toxicity evaluation by the Aquatic Toxicology Group is
determined on the basis of acute toxicity of the effluent in comparison with
instream waste concentration. Acute toxicity is determined by a 48 hour screening
static bioassay using Daphnia pulex.
For each on —site, flowthrough bioassay, a pre —test site inspection 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.
Sampling is done above chlorination unless otherwise specified.
4) Determine possible areas for dilution sampling (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 Daphnia pulex acute and static renewal Ceriodaphnia sp. reproduction bioassays
to determine the range of concentrations of effluent for the flowthrough bioassay, 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.
Upon actual arrival on —site with the mobile laboratory, dilution water is obtained
and dilution and effluent pumping systems are set up and tested. Two to three week
old fathead minnows are wet transferred to the test chambers (containing
approximately one liter of dilution water), ten fish to a 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 bioassay 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 Ceriodaphnia static renewal reproduction bioassay using newborn organisms is
begun the first day on —site. The organisms are transfered 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 in a 25
degree cent i gade incubator with 10 I ight:14 dark photoper i od. Test organisms are fed
a mixture of yeast and algae.
Individual chemical/physical parameter meters are calibrated daily according to DEM
standards. Hydrolab systems measure and record dissolved oxygen, pH, temperature,
and specific conductance in the test chambers with the highest and lowest
concentration of effluent at 15 minute intervals throughout the test. These systems
are calibrated at test initiation, the mid —point of the test, and test
termination.Data from these systems is recovered daily and stored on magnetic tape
and hard copy. On alternate days, samples of dilution water, effluent at the sampling
site, final effluent, and the receiving stream upstream and downstream of the
-25-

discharge point are analyzed for hardness. On variable effluents, daily residual
chlorine measurements will be made at the above described sites.
During the on —site evaluation, Biological Monitoring Group personnel collect benthos
samples at the upstream, downstream and dilution sites (see Benthic
Macroinvertebrate 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, dilution water is collected (where
appropriate), effluent and dilution pumping systems are checked and adjusted as
necessary, and pH, dissolved oxygen, and fish mortalities are recorded for each
chamber.
Two separate 24 hour composite samples of effluent are collected by means of an
automatic sampler for chemical analysis. Receiving stream and dilution water
samples are also taken for chemical testing.
Static 48 hour Daphnia pulex bioassays are conducted on a 24 hour composite sample
of the effluent and a grab sample of the influent.
A photographic record is made of the treatment facility, sampling points, receiving
stream, and sampling procedures while on —site.
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.
Several special care operating procedures should be mentioned. At facilities that
discharge for only a portion of the day, effluent samples are composited by the
dilutor system into a large reservoir on board the mobile laboratory for use as the
effluent while discharge is not in progress. 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. In the event that actual receiving waters are
deemed unfit for the test (i.e. potentially toxic), an alternate source of dilution
water is sought in the vicinity.

Ceriodaphnia ,s.. Reproduction Bioassay Procedure
Aquatic Toxicology Group
N. C. Division of Environmental Management
The Ceriodaphnia aquatic bioassay is conducted to estimate the effect of an
effluent or other water sample on reproductivity. The cladoceran Ceriodaphnia
sL is used as test organism in a 7 day static renewal bioassay. A control and 8
concentrations of effluent ranging from 0.01% to 100% are typically used. There
are 10 animals per conoentration, each animal in a one ounoe polystyrene test
chamber with 15 mis of solution. The test is conducted in a 25 degree centigrade
incubator with a 14 light/ 10 dark photoperiod.
The test is initiated with newborn animals, or neonates. Adults having brood
sacs of 5 or more eggs with visible eyespots (indicating eggs are about to be
released) are isolated and checked periodically. Neonates are removed and •
grouped according to time of birth. Selected groups are then composited to make
the youngest set of 90 or more neonates born within a 4 hour period. The test is
begun when the neonates are introduced into the test chambers. Temperatures must
be within 2 degrees centigrade for transfer.
The animals are transferred daily to new test chambers containing freshly mixed
solutions. Chemical/physical parameters are measured twice for each batch of
solutions. The initial value is taken before the animal is introduced and the
final value after the animal has been transferred out the next day. Dissolved
oxygen of greater than 40% saturation is necessary.
The animals are fed daily, just after transfer. Each animal receives 1/2
standard dose of yeast and 1/2 standard dose algae (one drop or 0.05 mis of a
solution made by dissolving 0.25 grams active dry baker's yeast in 100 mis of
distilled water plus one drop of a solution of 1.71 x 106 cells/ml Selenastrum
capricornutum).
As reproduction begins, only the adult is transferred to a 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 10% in control test organisms invalidates a test.

Benthic Macroinvertebrate Procedure
Biological Monitoring Group
N.C. Division of Environmental Management
The sampling methodology requires that a stream or river be
wadable. High water conditions may severely impair sampling
efficiency by making critical habitats unaccessible. A fixed
number of samples are collected for each station. These include:
2 kick net samples of riffle and snag areas; 3 sweep net samples
of bank areas and macrophyte beds; 2 fine mesh washdown samples
of rocks and logs; 1 elutriated sand sample; 1 leafpack sample;
and 1 visual search of rocks, logs, leaves, and substrate. The
benthic macroinvertebrates are picked out with tweezers and
preserved in alcohol. A collection card is filled out which
includes such data as canopy cover, dissolved oxygen, pH, stream
temperature, substrate composition and stream morphology at the
site. Organisms are identified to the lowest possible taxonomic
level, generally to species. Density of each taxon is rated as
Rare (1 or 2 individuals), Common (3 to 9), Abundant (10 or
more). Most organisms may be identified using only a dissecting
microscope, but Oligochaeta and Chironomidae must be mounted and
identified with a compound microscope. Reference collections are
maintained and all samples are kept and stored by study area.
The first level of analysis summarizes the data by total -number
of taxa or "taxa richness" (S) and density (N) for each
station.The association of good water quality with high taxa
richness is intuitively obvious even to the non -biologist.
Increasing levels ofpollution gradually eliminate the more
sensitive taxa, leading to lower and lower taxa richness. Clean,
unstressed, aquatic communities are characterized by a density
(N) and taxa richness (S) above average levels. Toxic stress
(including pesticides and metals) reduces both S and N below the
average. Sediment stress, especially at low levels, tends to
decrease density, but affects taxa richness only slightly.
Finally, nutrient enrichment tends to increase the total number
of organisms, while selectivelyfavoring a few types of organisms
tolerant to this type of pollution.
The second level of analysis summarizes data by taxonomic groups
(mostly orders of insects). A particularly useful parameter is
the "EPT" value: the sum of the taxa richness for the intolerant
insect groups Ephemoroptera, Plectoptera, and Trichoptera. The
EPT value is consistantly related to water quality.
The final step in data analysis is to summarize the data
separately for each taxa.The presence or absence of individuals
of "indicator species" is, in itself, insufficient for
characterizing water quality. Tolerant species are present in all
aquatic habitats, however these species will usually become
dominant only in polluted systems. Information on pollution
tolerance of any given taxon, combined with quantitative data on
-28-

its distribution can often be related to specific chemical or
physical changes in the environment.

List of Definitions
Aquatic Toxicology Group
N. C. Division of Environmental Management
Accli motion - refers to the process of gradually edj usti ng organisms from eater 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 en organism; usually
defined es death of that organism.
Application factor - e vel ue which estimates en i nstmam toxicant level that will be safe et a chronic level
for resident organisms from acute toxicity data, usuall y defined by a fraction of the LC50•
Aquatic - having to do with eater.
Aquatic Toxicology Group - the group within the Biological Services Unit (Water Duality Section) which
performs egoistic bioesseys for the Division of Environmental Management. The Group is located et
the Cary laboratory facilities. All test organisms (including Daphnia pulex, Ceriodaphnie IQ, and
fathead minnows) are cultured at these facilities by Aquatic Toxicology personnel.
Benthos/Benthic mecroi nvertebretes - e vide assemblage of invertebrate animals (i nsects, crustaceans,
molluscs, etc.) which live in streams, are en important food source for fish populations, and are
used es long term eater quality indicators.
Bioassay - e test used to determine the effects of a chemical or substance on an organism.
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.
Ceriodaohnia - a smell cledoceren crustacean. It is found throughout most of North America end obtains
e maximum size of approximately 1 mm. This organism has been adopted for aquatic bioassay
testing because of its small sire, ease of culture under laboratory conditions, stability of genetic
strains, end sensitivity to toxic substances. It is generall y used in e 7 day static renewal
mini -chronic' bioassay testing for mortality, time to sexual maturity end reproductive rate.
Ceriodeohnia ;Lis 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 usuell y measured es a non -fatal response
(eg. reduction in growth, egg production, predator avoidance, feeding rate, etc.). Test for chronic
toxicity are frequently performed duri ng the entire life cycle of the organism.
Chronic vel ue(ChV) : A numeric value representing the geometric mean of the numeric values of
concentrations analyzed es the No Oberaerved Effect Concentration (N.O.E.C.) and the lowest
Oberserved Effect Concentration (1.0.ECC.) by chroic toxicity testing. The chronic value is an
eeti mete of the toxicant conosntr stion that will be the actual no effect concentration bend on the
-30-

chronic effect tested. ChY-Antiloq(( Log i OL.O.E.C.♦ Log 1 ON.O.E.C.) /2)
Composite - a sample or method of sampling used to obtai n data on a substance which may nary over time
or space. for example, a time or temporal composite of a stream would be one collected et
intervals of time et the same location. This is frequently accomplished with automatic sampling
devices.
kaki' wax (eater flea) - e smell ciedoceren crustacean. It is found throughout most of North America
end obtains a maximum size of approxi motel y 3.5 mm. This organism hes been adopted for aquatic
bioassay testing because of its smell size, ease of culture under laboratory conditions, stability of
genetic strains, and sensitivity to toxic substances. It is generally used in e 48 hour static
bioassay testing for mortality. D. pulex is widely accepted in the field of aquatic toxicology for
testing in moderately soft eaters.
Design flow - the volume of water and waste that is initially planned to pass through a facility or waste
treatment plant end still allow maximum operating efficiency. Design floe is usually expressed in
millions of gallons per day (mgd).
Dilution (eater) - the water used in bioassay tests to dilute the waste voter to various concentrations
(expressed es 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 toe modified Mount and Brungs 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) .
Electrofishing - method for collecting fish using electrical shock to momentarily stun the fish so they float
to the surface and are easily netted.
Effluent - the waste water writing a facility which is discharged es treated waste to a stream ores
untreated waste to some other facility.
Fathead minnow (Pimeohelas promeles) - e small fish which occurs throughout much of North America. It
obtains a maximum size of approximately 100 mm and is raised commercially as bait fish. The
fathead minnow has been raised for numerous generations in a number of laboratory culture for
use in toxicity testing. The fish can produce eggs year round in the laboratory environment under
correct conditions which produce test organisms as needed.
Flow -through - the floe -through bioassay utilizes which either continuously of occasionally replace
effluent/toxicant concentrations throughout the test in an attempt to simulate stream conditions
where new effluent and dilution water are continually flowing through an organism's habitat.
Hydrolab} - e multi parameter instrument which measures and records temperature, pH, dissolved
oxygen, and specific conductance of eater.
"Use of this term or system does not constitute an endorsement
I nstreem waste concentration (IWC) - the percent concentration of an effluent/toxicant which is present
in e stream under assumed worst case conditions. The IWC is derived from the formula: [ Df /
—31—