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Document Date:
March 29, 1988
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DIVISION OF ENVIRONMENTAL MANAGEMENT
March 29, 1988
MEMORANDUM
TO: Preston Howard, QWilm' gton Regional Office
FROM: Steve W. Tedder L�1�
SUBJECT: Toxicological Evaluation - Occidental Chemical Corporation,
NPDES No.--N6OO2-6 3, New Hanover County
Nc.a oa3-7 S`
Attached is the final report concerning an intensive toxicological
evaluation of the Occidental Chemical Corporation facility in New Hanover
County.
If there are any questions., please contact myself or Ken Eagleson at
(919)733-5083.
SWT:ps
cc: Ken Eagleson
Larry Ausley
Bob DeWeese
Trevor Clements
Jay Sauher
Jim Overton
iiuinu I>I-
#t1IN111lo
Occidental Electrochemicals
Toxicity Examination
NPDES #NC0026051
NIIIIuIIII
MINIM
North Carolina Department of Natural
Resources & Community Development
MOBJ
Bioassay and Biomonitoring v
LABORA TOR Y
NORTH CARD IA DEPARTMENT OF NATURAL
RESOURCES AND COMMUNfTY
D EVELO PM ENT
WATER QUALITY SECTION
March, 1988
OCCIDENTAL ELECTROCHEMICALS
TOXICITY EXAMINATION
NPDES NO. NC0003875
NORTH CAROLINA DEPARTMENT OF NATURAL RESOURCES
AND COMMUNITY DEVELOPMENT
DIVISION OF ENVIRONMENTAL NA AGEMENT
WATER QUALITY SECTION:
March 1988
TABLE OF CONTENTS
Page
Introduction 1
Toxicity Examination 4
Chemical Sampling Analysis 6
Conclusions 13
Recommendations 14
Footnotes 15
Appendix
Ceriodaphnia dubia Test Procedure 17
96 Hour Flow -Through Test Procedure _............. 18
Ceriodaphnia Reproduction Test Procedure.... ... 20
Benthic Macroinvertebrate Procedure.... 21
List of Definitions . , 22
LIST OF FIGURES
Figure 1. Schematic Diagram of Occidental Electrochemicals
Waste Treatment Facilities 3
Figure 2. Seven Day Ceriodaphnia Mean Cumulative Reproduction 7
Figure 3. Study Area and Sampling Sites, Occidental Electrochemicals9
LIST OF TABLES
Table 1. Self -Monitoring Toxicity Test Results ... 4
Table 2. Sampling Station Descriptions - Occidental
Electrochemicals, Inc 8
Table 3. Results of Chemical Analyses. 10
Table 4. Chloride Toxicity Data 13
Table 5. On -site Chloride Analyses .. 13
INTRODUCTION
An intensive on -site toxicological evaluation was conducted at the Occi-
dental Electrochemicals Corporation (NC0003875) from May 11 through 16, 1987.
Occidental produces sodium bichromate and chromic acid from chrome ore by high
temperature oxidation and acidification. Current production is 290 tons sodium
bichromate and 60 to 80 tonschromic acid per day with 210 employees working 4
shifts. The processing plant has been in production since 1971. Wastewater
generated from the chromium processing plant is discharged to the Northeast
Cape Fear River. The Occidental facility has two other wastewater discharges
(cooling water and automobile rinse water) which were not tested during this
evaluation.
This report contains findings of toxicological and chemical evaluations
performed including the following:
1) 48 hour static Ceriodaphnia dubia toxicity tests onwastewater treat-
ment plant influent and effluent to determine acute toxicity;
2) 96 hour static toxicity test using Pimephales promelas (fathead
minnows) on effluent to determine acute toxicity;
3) Seven day Ceriodaphnia dubia static replacement reproduction suppres-
sion toxicity test on effluent to determine acute and chronic toxicity;
4) 48 hour fractionation toxicity test on effluent in an attempt
to identify or rule out potential classes of constituents causing
acute toxicity;
5) Analysis of chemical samples collected from the wastewater treatment.
system influent and effluent and receiving stream above and below the
discharge.
The wastewater treatment process and facility at Occidental Electrochemi-
cals were designed specifically to treat chromium ore processing wastes. A
simplified schematic of the treatment process appears in Figure 1. The chro-
mium process wastewater, containing elevated levels of hexavalent chromium,
iron and aluminum, travels first to a large waste collection tank where an
agitator mixes the waste to prevent settling. From this tank, the waste is
pumped in 10,000 gallon batches alternately to six reactors where hexavalent
chromium (Cr+6) in the waste will be reduced to trivalent chromium (Cr+3) with
ferrous chloride pickle liquor. Here, an operator measures the amount of Cr+6
in the waste in order to determine the quantity of ferrous chloride pickle
liquor to be added to a particular reactor. Generally, each 10,000 gallon
batch of waste requires about 500 gallons of pickle liquor to reduce all of
the hexavalent chromium. Next, lime is added to form a chromium hydroxide
precipitate. This precipitate is passed through a chloride removal system,
which consist of .successive hydroclones and countercurrent washings in sludge
thickeners. The thickened sludge is discharged to holding lagoons or quarries
on the Occidental Chemicals plant site. In 1976 the chloride removal system
was added to wastewater treatment processes to decrease chloride concentra-
tions in the waste sludge (and as a result, increase chloride in discharged
wastewater). The effluent is made up of waste water from the chloride removal
and precipitate washing and thickening systems. This wastewater is passed
through a final sand filter to remove suspended solids and then discharged to
the Northeast Cape Fear River. Thisriver is designated as a "Class C-Swamp"
river in the Cape Fear River basin with a 7 day, 10 year low flow (700) of 15
cubic feet per second (cfs). The permitted effluent flow for the,process water
discharge is 0.747 million gallons per day (MGD), yielding an instream waste
concentration (IWC) of the effluent in the Northeast Cape Fear at this low
flow condition of 7.16Z.
Figure 1. Schematic Diagram of Occidental Electrochemical's Waste Treatment Process
Waste Collection Tank
Sand Filters
Station 02
Bioassay Sampling
Point
Station 02A
Influent Sampling
Point
To NE Cape Fear River
Reduction Reactors
Hydrocycloning
On May 1, 1986, the Division of Environmental Management required Occi-
dental to begin 48 hour Daphnia pulex static toxicity testing of its process
discharge on a monthly basis. The target acute toxicity value (LC50) for these
tests is >90%. The LCS0 value is the concentration of effluent lethal to fifty
percent of the test organisms. Results reported to date are presented in Table
1.
Table 1. Self -monitoring Toxicity Test Results for Occidental
Electrochemicals Corporation.
Month Test Type LC50
May, 198648 hour Daphnia pulex 53.95
June, 1986 48 hour Daphnia pulex 30.89
July, 1986 48 hour Daphnia pulex 39.59
August, 1986 Ceriodaphnia static acute 45.66
September, 1986 Mysid shrimp static acute 29
October, 1986 48 hour Daphnia pulex, 26.-01
November, 1986 48 hour Daphnia pulex 36.22
December, 1986 48 hour Daphnia pulex 28.28
January, 1987 48 hour Daphnia pulex 26.72
February, 1987 48 hour Daphnia pulex 47.66
March, 1987 48 hour Daphnia pulex 49.9
April, 1987 48 hour Daphnia pulex 42
May, 1987 48 hour Daphnia pulex 29.2
June, 1987 48 hour Daphnia pulex 48
July, 1987 48 hour Daphnia pulex 43
August 1987 48 hour Daphnia pulex 44
September, 1987 48 hour Daphnia- pulex 31
October, 1987 48 hour Daphnia puler 41.25
November, 1987 48 hour Daphnia pulex- 41.59
December, 1987 48 hour Daphnia pulex 32_.22
January, 1988 48 hour Daphnia pulex 25.49
TOXICITY EXAMINATION
An on -site toxicity examination was conducted at the Occidental Electro-
chemicals wastewater treatment facility in response to toxic results shown by
the planes effluent in toxicity tests performed in 1984 and 1986. Results of
these tests are presented. below.
Previous Toxicity Testing Results from Occidental Electrochemicals
Test Date Test Type LC50
October 30, 1984 48 hour Daphnia pulex 53%
March 13, 1986 48 hour Daphnia pulex 33%
May 28, 1986 48 hour Daphnia pulex 40%
May 28, 1986 48 hour Ceriodaphnia 47%
Toxicity tests performed on -site included 48 hour Ceriodaphnia dubia
static toxicity tests on the facility's effluent and influent, a 96 hour fath-
ead minnow static toxicity test, and a seven-day Ceriodaphnia dubia life cycle
test to determine chronic lethality. In addition, effluent fractionation tox-
icity testing, similar to that described by draft EPA protocols, was conducted
while on -site in order to identify or rule_out classes of constituents causing
toxicity. Dilution -water for these toxicity tests was obtained from the Nor-
theast Cape Fear River at Occidental's water intake, above the facility's dis-
charge. This water was tested prior to use at the -Aquatic Toxicology Labora-
tory using the Ceriodaphnia reproduction test. Reproduction in this dilution
water was similar to that of laboratory culture water.
A grab sample of the influent and a 24 hour composite sample of the
effluent were collectedMayMay 14. Ceriodrpdania dubia 48 hour static toxicity
tests were conducted on these samples with resulting LC50's of 0.019% for the
influent and 7.3% for the effluent. A 96 hour fathead minnow static toxicity
test resulted in an LC50 of 95.3%.
A seven-day Ceriodaphnia static replacement toxicity test was performed
on dilutions of effluent to assess reproductive impairment as well as lethal
chronic toxicity. This test was conducted with 24 hour composite samples col-
lected daily. This test was initiated on -site on May 11, 1987 and terminated
at the Aquatic Toxicology Laboratory in Cary, N.C. on May 18, 1987. Trimmed
Spearman-Karber analysis of the mortality data yields an LC50 of 29.97% with
95% confidence intervals of 22% and 40%. Reproduction in concentrations
0.01%, 0.1% and 7.5% was similar to that in NE Cape Fear River water upstream
of the Occidental wastewater discharge. There was significant reproduction
suppression in the 25% effluent concentration. :There was complete mortality
in effluent concentrations 50%, 75% and 100%. Figure 2. graphically presents
mean reproduction.
Effluent fractionation toxicity testing, similar to that described by
draft EPA protocols, was conducted while on -site in an attempt to identify or
rule out potential classes of constituents causing toxicity. Effluent was
diluted to 35% before fractionation to provide workable median time till death
results. Among procedures attempted, only the sample that was basified,
aerated, and returned to original pH showed a significant decrease in toxic-
ity. This indicates the presence of volatile basic compounds with a pKa(a
measure of acidity) at least one to two units lower than pH 11. This group
includes ammonia (pKa=9.25) and analine (pKa=4.6) and other relatively
volatile basic compounds (organic and inorganic) which are volatile at pH 11.
Toxicity was not completely reduced from any of the fractions, indicating a
toxicant present in the effluent which the fractionation procedures do not
affect. Examples of the classes of compounds not affected by the fractiona-
tion procPditres include_anions in general, complex anionic forms of metals
such as arsenic, selenium, or chromate, and polar organics.
CHEMICAL SAMPLING
Two series of chemical samples collected during the evaluation were ana-
lyzed at the Division of Environmental Management chemistry laboratory. Table
2. lists descriptions of the sampling stations. All samples were collected as
instantaneous grabs, with the exception of Station 02 (effluent bioassay samp-
ling point), which were taken as 24 hour composites Figure 3., a map of the
Figure 2. Seven Day Mean Cumulative Reproduction
Mean _Cumulative, , Reproduction
study area, illustrates sampling site locations. Results of chemical analyses
are documented in Table 3.
Table 2. Sampling Site Descriptions.
Station 01 - Northeast Cape Fear River at the Occidental Electrochemicals
water inlet ditch, approximately 0.4 miles upstream of the waste
treatment works' discharge. This site served as dilution water
for all bioassays performed;
Station 02 - Occidental Electrochemicals effluent from sand filters prior to
confluence with domestic wastewater.
Station 02A- Occidental Electrochemicals influent from chromium reduction
reactor vessel.
Station 03 - Northeast Cape Fear River at NC 133, approximately 2.3 miles
below the Occidental waste treatment facility's outfall_
Metals analyses revealed copper concentrations of 14 ppb and 12 ppb in
the effluent (Station 02) samples of May 14 and 16 respectively. Grab samples
taken from the Northeast Cape Fear River downstream of the plant's discharge
on these same days showed copper concentrations of 2.9 ppb and 2.5 ppb,
respectively. Copper was detected in Northeast Cape Fear River samples taken
upstream of the Occidental discharge on both sampling dates at levels -of 3.8
ppb and 2.0 ppb, respectively.
Silver was detected in effluent samples from both dates at levels of 30
ppb on the 14th, and 23 ppb on the 16th.. Silver levels were below detection
limits(<25 ug/1) upstream and downstream of the of the discharge on both samp-
ling dates.
Chromium was detected in the eff l tint sample of May 14 at 15 ppb and 8.4
ppb in the effluent sample of May 16. Chromium levels were below detection
limits (<5.0 ppb) upstream and downstream of the plant discharge on both samp-
ling dates.
Figure Occidental Electrochem1cals Study Area
NE Cape Fear River
SR.1002
M 2 miles
Occidental
ectrochemicals
Table 3. Chemical Analyses Results -Occidental Electrochemlcals, Inc.
Permitted Flow (MGD)
15.000
7010 (CFS)
0.747
Instream Waste Conc. (%)
7.16
Upstream
Effluent
Influent
Downstream
Chemical/Physical
Units
Water Oual.
Sta 01
Sta 02
Sta 02A
Sta 03
Analyses
Standards
870514
870514
870514
870514
BOD
PPM
5
COD
PPM
49
330
<5
50
Residue TOTAL
PPM
140
10000
240000
130
volatile
PPM
66
410
11000
69
fixed
PPM
69
9800
280000
60
Residue SUSPENDED
PPM
8
16
160000
12
volatile
PPM
3
7
5500
7
fixed
PPM
5
9
150000
5
pH (standard units)
6.0-9.0
6.4
6
10
6
Acidity
PPM
23
12
NA
19
Alkalinity
PPM
19
25
20000
14
Chloride
PPM
24
5000
710
21
Chromium Hex.
PPB
<50
<50
420000
<50
Cyanide
PPB
0.02
Hardness
PPM
37
4900
210
35
Specific Conductance
uMhos/cm
130
11000
6800
130
NH3
PPM
0.09
0.28
0.21
0.09
TKN
PPM
0.4
0.7
10
0.5
NO2,NO3
PPM
0.54
1.9
0.82
0.52
P. total
PPM
0.13
0.16
0.29
0.12
Aluminum
PPB
400
300
650000
450
Cadmium
PPB
2
<20
<5.0
<10
<2.0
Chromium (Total)
PPB
50
<5.0
15
480000
<5.0
Copper
PPB
15(AL)t
2
14
64
2.9
Iron
PPB
1000
710
140
260000
710
Mercury
PPB
0.2
<0.2
<0.2
0.2
<0.2
Manganese
PPB
<25
40
600
<25
Nickel
PPB
50
<10
<10
95
<10
Lead
PPB
25
<10
<10
65
<10
Silver
PPB
10(AL)
<25
30
35
<25
Zinc
PPB
50(AL)
<10
<10
280
<10
t Values represent action levels as specified In .0211(b)(4)
Fresh Water Classifications Standards I
Table 3. Chemical Analyses Results -Occidental Electrochemlcals, Inc.(contlnued)
Permitted Flow (MGD)
0.747
7010 (CFS)
15.000
Instream Waste Conc.(%)
7.16
Upstream
Effluent
Influent
Downstream
Chemical/Physical
Units
Sta 01
Sta 02
Sta 02A
Sta 03
Predicted stream**
Analyses
870516
870516
870516
870516
conc. at 7010
BOD
PPM
COD
PPM
51
380
<5
51
Residue TOTAL
PPM
140
9100
190000
140
volatile
PPM
77
120
5800
74
fixed
PPM
64
9000
190000
61
Residue SUSPENDED
PPM
10
17
110000
11
volatile
PPM
5
8
4000
2
fixed
PPM
5
9
110000
9
pH (standard units)
6.2
6.1
10.6
6.1
Acidity
PPM
26
24
2200
24
Alkalinity
PPM
21
23
18000
20
Chloride
PPM
22
4500
400
21
340.100
Chromium Hex.
PPB
<50
<50
730000
<50
Cyanide
PPM
Hardness
PPM
37
4500
65
36
Specific Conductance
uMhos/cm
140
12000
6600
130
NH3
PPM
0.12
0.27
0.08
TKN
PPM
0.5
1.2
0.4
NO2,NO3
PPM
0.58
1.6
0.58
P. total
PPM
0.13
0.13
0.12
Aluminum
PPB
500
250
140000
500
19.690
Cadmium
PPB
<2.0
<2.0
<10
<2.0
Chromium (Total)
PPB
<5.0
8.4
400000
<5.0
0.838
Copper
PPB
3.8
12
87
2.5
0.931
Iron
PPB
800
121
340
740
9.344
Mercury
PPB
<0.2
<0.2
<0.2
<0.2
Manganese
PPB
<25
60
760
<25
3.580
Nickel
PPB
<10
<10
73
<10
Lead
PPB
<10
<10
<50
<10
Silver
PPB
<25
25
45
<25
1.969
Zinc
PPB
<10
<10
180
<10
** Values represent predicted instream concentrations using average effluent
concentrations and assuming upstream concentrations of 0.
Chloride was detected at 5000 ppm in the effluent sample of May 14 and
4500 ppm in the effluent sample of May 16. Levels of chloride in the Nor-
theast Cape Fear River upstream of the Occidental discharge were found to be
24 ppb on May 14 and 22 ppb on May 16. Downstream of the discharge, chloride
was detected at 21 ppb on both sampling dates.
• Copper LC50's have been reported as low as 17 ppbB in 48 hour Ceriodaph-
nia reticulata bioassays in water of hardness 45 ppm. LC50's for silver have
been reported as low as 1.5 ppbC in Daphnia magna bioassays in water of
hardness of <100 ppm and 1.4 ppbD (EC50) in Ceriodaphnia reticulata 48 hour
bioassays in water of hardness 240 ppm. Chromium LC50♦s have been reported of
51,400 ppbE for Daphnia magna in water of hardness 195 ppm. All of these
metals were less toxic to fathead minnows. It should be noted that the hard-
ness of the Occidental effluent was considerably higher than hardnesses asso-
ciated with the above data, averaging 4750 ppm over the two sampling dates.
Higher water hardnesses generally reduce the toxicity of metals.
There were no organic compounds detected in Occidental's effluent or
influent on either sampling date..
Chloride most likely accounted for the greater part of the chronic and
acute effects observed in the Ceriodaphnia and fathead minnow toxicity tests.
This agrees with results from the fractionation testing discussed above, as
chloride, an anion, is not removed in the fractionation procedure. Table 4
presents chloride toxicity data. There does appear to be another source of
toxicity as indicated by the static testing results during the on -site period
and results or self -monitoring bioassays performed prior to the on -site eval-
uation. A mysid shrimp (a salt water organism) bioassay was performed by the
facility yielding an LC50 of 29%. Chloride determinations performed on -site
(see Table 5.) indicate that the levels of chloride remained essentially the
same throughout the week of the evaluation. The 48 hour Ceriodaphnia static
test conducted on a 24 hour composite produced the lowest LC50 of any toxicity
test performed on the Occidental effluent to date, including the seven day
Ceriodaphnia chronic toxicity test performed during the same week. This
indicates effluent variability, specifically variability of a toxic constitu-
ent other than chloride. Silver constitutes a. candidate for a secondary tox-
icity source due to levels encountered (avg. of 27.6 ppb over the two sampling
dates).
Table 4. Chloride Toxicity Data
Orgaaism Test Type Result (ppm)
Daphnia pulex 48 hour static
LC50 = 3050F
Daphnia puler 21 day reproduction suppression
ChV = 3722
Ceriodaphnia dubia 48 hour static
LC50 = 1577G
Fathead Minnow 96 hour flow -through
LC50 = 6570F
Fathead Minnow 33 day early life stage
ChV = 298F
Table 5. On -site Chloride Analyses
Date
Chloride (mg/1)
5/11 5/12 5/13 5/14 5/15 5/16
4350 4500 4040 4263 3947 4158
CONCLUSIONS
The Occidental Electrochemicals waste treatment facility effluent dis-
played significant acute and chronic toxicity to Ceriodaphnia dubia. A 48
hour acute static toxicity test resulted in an LC50 of 7.3%. A chronic LC50
of 29.97% resulted from a seven day Ceriodaphnia dubia toxicity test. This
reproduction suppression test also yielded a no observed effect concentra-
tion(NOEC) of 7.5% and a lowest observed effect concentration(LOEC) of 25%
producing a chronic value (ChV) of 13.69%. Fathead minnows were less sensi-
tive to the Occidental waste as indicated by a 96 hour static LC50 of 95.3%.
Data collected during and prior to this investigation indicate that effluent
toxicity varies significantly. Accordingly, instream effects will be expected
to vary. Given the facility's instream waste concentration of 7.16% during low
flow conditions, acute toxicity to cladocerans and organisms of like or
greater sensitivity would be intermittently expected in the Northeast Cape
Fear River. If incidents of higher toxicity persist, more subtle chronic
effects would also be expected.
Analyses of chemical samples show elevated effluent concentrations of
chloride and silver. Silver and chloride were both present in concentrations
sufficient to cause acute mortality to Ceriodaphnia dubia.
RECOATIONS
1. The facility should develop a written toxicity reduction plan with a
schedule of completion included. Results of the monthly self -
monitoring toxicity tests specified by the facility's permit will
serve to evaluate progress of the toxicity reduction plan.
2. The source of silver should be investigated and efforts made to mini-
mize discharge of silver and chloride, and thus reduce observed acute
toxicity.
3. The facility may wish to consider performing furthpi- chemical frac-
tionation procedures in order to determine sources of toxicity not
detected by this evaluation.
FOOTNOTES
B Mount, D.I. and T.J. Norberg. A Seven -Day Life -Cycle Cladoceran Toxicity
Test. Environmental Toxicology and Chemistry. Vol. 3. pp 433. 1984.
Leblanc, G.A. 1984. Interspecies relationships in acute toxicity of chemi-
cals to aquatic organisms. Environ. Toxicol. Chem., 3:37-60.
D Elnabarawy, M.T., A.N. Welter, and R.R. Robideau. 1986. Relative sensitivity
of three Daphnid species to selected organic and inorganic chemicals. Envi-
ron. Toxicol. Chem., 5:393-398..
E Ambient Water Quality Criteria For Chromium,(USEPA, 1984),EPA 440/5-84/029.
F Birge, W.J. et. al. 1985. Recommendations on Numerical Values for Regulat-
ing Iron and Chloride Concentrations for the Purpose of Protecting Warmwater
Species of Aquatic Life in the Commonwealth of Kentucky. Memorandum of
Agreement No. 5429. Kentucky Natural Resources and Environmental Cabinet.
G EPA unpublished data, 1987.
Copies of all reports are available.
.APPEND LX
t
.17
48 Hour Cladoceran Screening Toxicity Test Appendix •
• Aquatic Toxicology Group
N. C. Division of Environmental Management
The Aquatic Toxicology 6roiip performs*48hour static.toxicity tests using clsdocerans D*mie galaand/or
Corigdeoligg, dial to estimata the toxicity -of waste discharge to aquatic life In receiving streams. All test and
sampling glassware and eguipmentwith are reined. ere washed with.soap and hot water, then rinsed in nitric' ecid,
acetone. end distilled/deidnited water. to remove toxins and contaminants. Effluent samples ere.collected by Del
Regional Ofnce 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, allowed to reach standard test
'temperature. and aerated if dissolved oxygen is below 40X saturation. Total residual chlorine is measured. The
effluent is then diluted with culture water.. typically to seven concentrations (with replicates) from 0 to 90R
of t Each. tact chamber receives 100 mis total volume and ten tent organisrns.0 24 hours old. Initial DO and pH
are Treasured in separ.ate surrogate veseels.of dilution and effluent solutions. The test is conducted in a 20 degree
centigrade incubator with s 162 hour.light:dark cycle. Mortality of the test organisms is recorded after .48 hours.
along with final pH. dissolved-oxygen.and temperature.
A 481otr LC54. or concentration of effluent lethal to 50% of the test organisms in 48 hours. is calculated from
the mortality data using Trimmed Spearman-iCarber analysis. An instream waste concentration (IWC) for the
ef(luent_in Ow-recafving stream is calculated using the wastewater trestsnent system permitted flow and -receiving
stream 7Q10 flow. The 450 and IWC are .then used to predict instream toxicity.
Guidance Documents:. .
1985. th:_S. f. P. A. Methods for measuring the acute toxicity of effluents to freshwater and
Third Ed. (fPA/600/4-85/013).
1977. iaaniltan, M. A., Russo, R. C.. and Thurston. R. V. Trimmed Spearman-Karber Method
Lethal Concentrations in Toxicity Bioassays. Environmental Science & Technology, Volume 1
1977. _.
marine organisms.
for Estimating Median
1, Number 7, July
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 thefacility site is performed in order to:
1)Detarmine appropriate erase for physical.plac,m.nt of the mobila.laboratory.
- -2) Acquire.proper equipment and :instaliatton needed forelectrical service.
3) Determine appropriate areas for of luent simpling and equipment needed for such. -Determine discharge
Sampling is done below cspecified:
hlorination'unless otherwise schedule.
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.ssmples of effluent and possible dilution waters for further static acute and static renewal
lion toxicity tests to determine the range of concentrations of effluent to be used for
the
e flowthrough toxicity test, to test for potential toxicity of possible dilution waters. and for fish acclimation to
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 requirement.s with appropriate facility personnel.
8) Determine appropriate samplingsites and -techniques .for benthic macroinvertebraie surveys.
All tested sampiing.glassware and equipment are. washed prior to.use with soap and hot water. then rinsed in
nitric acid. acetone, and distilledfdeionized 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.untii 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
NA the dilution and effluent pumping systems are turned on and the fathead minnow flowthrough toxicity testis
begun. A water bath is utilized to bring. the effluent and dilution water to a constant 20 degrees centigrade. Test
organisms are fed newly-hatchetbrine-shrimp twice daily throughout the test. . .
A 7 day Cethilimblik dulgit static reaewai..reproduction toxicity test using newborn organisms is begun the first
day.o� te. The rg sms_ are transferred to fresh dilution and efnu¢nt solutions daily andinitial Ind final pH and
oxygendissorecord d.lbe number of young born per organismh_per day is recorded and mean cumulative
-reproduction is calculated for each cax:entration. 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/ aifaifs/fermented trout chow mixture with
Sm cendocaubmadded per organism per. day.(See Cadadagthda
Appendix)Reproduction Toxicity Test
Individual chemtcal/phystcal parameter meters are calibrated daily according to DEM standards. At 15 minute
Intervals throughout the test. Hydrolab systems measure and record dissolved oxygen, pH.
specific conductance In the Lek chambers -with the h temperature. and
calibratedst test initiation, mi highest and lowest concentration of effluent. These systems are
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 Benthic Macroinvertabrate Survey appendix). Where
appropriate. electrofishing is undertaken upstream and downstream of the discharge to obtain resident fish
population data. On i site -specific basis. various other efforts are undertaken. such as monitoring dissolved
oxygen levels in the receiving strean.
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 charmer. 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 levets'in the chambers are monitored closely in
order to preventlevels from dropping below 40R saturation at test •temperatures.
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Two separate 24 tour c anPosite samples of efrlusnt are collected for chemical analysis by means of an automatic
sampler. Influent, receiving stream, end -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 tour of the facility is conducted. The actual treatment process is reviewed to ascertain the quality of the
operation of the treatment system end 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 fecility.;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.
8reakdovm and packing routines are performed and the mobile laboratory is transported back to the Cary Aquatic
Toxicology Laboratory. The fierigdgehala duWa reproduction toxicity* test is continued at the lab until the 7th test
day.
•
Ceriodaphnia dubia Reproduction Toxicity Test Appendix
Aquatic Toxicology Group
N. C. Division of Environmental Management
The cladoceran rgeriodaphnlogdge, Is used as test organism In a 7 day static renewal toxicity test. This test
estimates the effect of an affluent or other water sample on repoduction. A control and 8 concentrations of
effluent ranging from 0.01 X to 100% are used. There are 10 organisms per concentration, each organism in a one
ounce polystyrene test chamber with 15 mils of solution. The test is conducted at 25 degrees centigrade with .1,
light/ 8 dark hour photoperiod.
Alt 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. Ali 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/1. 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 negates 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 fly. Each organism receives 0.1 ml of fermented trout chow -yeast -alfalfa food with Saleneskum
candramnutum 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
sing microscope. A mean number of young produced per adult is calculated for each lion. Mortality
of greater than 20R 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)
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 emciency 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 nurnber 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 ciassification to each station
(Excellent, Good, Good/Fair, Fair, and Poor). Bioclassiftcation criteria for several ecoregions have been
developed, including mountain, piedmont. inner coastal, and outer coastal. The 'bioclassiflcation' 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 Tridaptera. Only four samples
we 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 (SEPT) and EPT abundance (lpT). Abundance
values are calculated using 1 for Rare species, 3 for Common species, and 10 for Abundant species.
These values we then summarized for all EPT taxa.
List of Definitions
Aquatic Toxicology 6rosp
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 cthemical 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
&'� -the group within the Biological Services Unit (Water Quality Section) which performs
. aquatic toodc1ty tests for the Division of Environmental Management. The Group is located at the Cary
laboratory facilities. All test organisms (including Daphnia hex, Ceriodaohnia §L, 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.
Csriodaphnia ma's - a small cladoceran crustacean. It is found throughout most of North America and obtains a
maximum sizeof approximately 1 mm. This organism has been adopted for aquatic toxicity testing because of
its snail 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 rate. Ceriodaphnia dubi,� 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 dining 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 rxrreric 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 tasting. The chronic value is an estimate of the toxicant concentration that wily
be the actual no effect concentration based on the chronic effect tested. ChVWAntilog((Log 10L.O.E.C.+
}
Log1.0N O.E.C.)/2) -
Cladoceran - Commonly known as water fleas, the Order Ciadocera belongs to the Class Crustacea which includes
shrimps and crabs. Clsdocerans 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 time or space: For
example, a time or temporal composite of a stream would be ore collected at intervals of time at the same
location. This is frequently accomplished with automatic sampling devices.
Daphnia pulex. - a snail 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 46 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 (0F) - 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 *grossed in millions of gallons per
day (mgd).
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 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).
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,
..Electrolshfng:;- mdUiod'for collecting f s_ h .using electrical shock to momentarily stun the fish so they float to the
• surface and .are easily netted. - .
Effluent - the wads water exiting a facility which is discharged as treated waste to a stream or as untreated or
'pre-treated waste tosome other fadlity.
Fsttw.d minnow (Pimevhelas, prmmwlas) - a 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 cultures for use in toxicity testing. The fish can
produce eggs year round in the laboratory environment under correct conditions, to provide test organisms as
needed.
Flow -through - the flow -through toxicity test utilizes a mechanical dilutor which either continuously or occasionally
replaces the effluent/toxicant and:dikttion water in the test chambers with fresh solutions throughout the test
in an attempt to sample the•variaeb1lfty of effluent toxicity throughout the test period.
HYdrola" - imultiparamuter� .Instrument which measures and records temperature, pH, dissolved ox
ygen. and specific
conductance Older*.
instream waste concentration.f WC) - the percent concentration of an effluent/toxicant which is present in a stream
• under worst case conditions (defined as 7010 low flow). The IWC is derived from the formula: IPF / (7010 +
• PF)j x 100 = IWC (2), where PF is the permitted flow (in cfs) of the facility in question and 7010 is the 10
year: 7 day. low flow (in cfs) of the receiving stream.
LC50 - that concentration or percentage of a waste/chemical/substance which is lethal to 50% of test organisms over
a stated period of time.
Lowest Observed Effect CarcentraUon (L.O.E.C.) The lowest concentration of toxicant to which orga iwis are exposed
in a life -cycle or partial life -cycle test. which causes a statistically significant adverse effect on the
observed parameters (usually survival. growth. reproduction .and/or egg hatchability).
NPOES - National Pollutant Discharge Eiimmstion. System. A system devised by the Federal Government and adopted by
North -Carolina for the permitting, monitoring, and pollution abatement of dischargers to surface waters. •
Neonate - roughly, translated to newly born. In reference to cladoceran, the neonate refers to the life stage in the first
and early second fnstar. generally the first 24 hours of its life.
No Observed -Effect Concentration (N.O.E.C.) - The highest concentration of toxicant to which organisms are exposed in
a life -cycle or partial life -cycle test, which causes no statistically significant adverse effect on the observed
parameters (usually survival. growth. reproduction ,and/or egg hatchability).
Permitted flow (PF) - the volume of water and waste that is allowed by the NPOES permit to pass through a facility or
waste treatment. plant. Permitted flow is usually expressed in millions of gallons per day (mgd).
Screening toxicity test - s testing system established to determine general levels of acute toxicity of
compounds/discharges using start -term toxicity tests with sensitive species.
7Q10 - the measurement.of a stream's lowest average daily flow over a 7 day period during a 10 year span. generally
stated as flow in cubic feet per second (cfs).
Sodium lauryl sulfate (SLS) - a chemical accepted -by EPA as a toxicant for quality assurance testing of the health of
aquatic organisms.
Static - refers to an aquatic toxtdty test in which toxicant/effluent concentrations are set up at the beginning of the
test and not changed or replaced for the rest of the test. This test is generally short term as compared to a
flow -through or replacement test because of potential degrsdaUon of the toxicant/effluent. "
Taxa - refers to a group of genetically related organisms. (i. e. genus, order. species).
Taxa richness - number of taxa.
Toxicity - the adverse effect of a chemical/substance on an organism. Toxicity is usually defined as a fatal or
non -fatal response over a given period of time.
Toxicity Test - a test used to determine the effects of a chemical or substance on an organism.
UT or Unnamed tributary - a term given to streams which have no accepted name.
'Use of this term or system does not constitute an endorsement