EPA/600/8-86/005
May 1986
Validity of Effluent and Ambient Toxicity
Tests for Predicting Biological Impact
Naugatuck River, Waterbury, Connecticut
Edited by
Donald I. Mount, Ph.D.a
Teresa J. Norberg-King"
Alexis E. Steen"
"Environmental Research Laboratory
U.S. Environmental Protection Agency
6201 Congdon Blvd.
Duluth, Minnesota 55804
bEA Engineering, Science, and Technology, Inc.
Hunt Valley/Loveton Center
15 Loveton Circle
Sparks, Maryland 21152
Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Duluth, MN 55804
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Notice
This document has been reviewed in accordance with U.S. Environmental
Protection Agency policy and approved for publication. Mention of trade names
or commercial products does not constitute endorsement or recommendation
for use.
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Foreword
The Complex Effluent Toxicity Testing Program was initiated to support the
developing trend toward water quality-based toxicity control in the National
Pollutant Discharge Elimination System (NPDES) permit program. It is designed
to investigate, under actual discharge situations, the appropriateness and utility
of "whole effluent toxicity" testing in the identification, analysis, and control of
adverse water quality impact caused by the discharge of toxic effluents.
The four objectives of the Complex Effluent Testing Program are:
1. To investigate the validity of effluent toxicity tests in predicting adverse
impact on receiving waters caused by the discharge of toxic effluents.
2. To determine appropriate testing procedures which will support regulatory
agencies as they begin to establish water quality-based toxicity control
programs.
3. To provide practical case examples of how such testing procedures can be
applied to effluents discharged into a receiving water.
4. To field test short-term chronic toxicity tests including the test organisms,
Ceriodaphnia sp.a and Pimephales promelas.
Until recently, NPDES permitting has focused on achieving technology-based
control levels for toxic and conventional pollutants in which regulatory
authorities set permit limits on the basis of national guidelines. Control levels
reflected the best treatment technology available, considering technical and
economic achievability. Such limits did not, nor were they designed to, protect
water quality on a site-specific basis.
The NPDES permits program, in existence for over 10 years, has achieved the
goal of implementing technology-based controls. With these controls largely in
place, future controls for toxic pollutants will, of necessity, be based on site-
specific water quality considerations.
Setting water quality-based controls for toxicity can be accomplished in two
ways. The first is the pollutant-specific approach which involves setting limits for
single chemicals, based on laboratory-derived no-effect levels. The second is the
"whole effluent" approach which involves setting limits using effluent toxicity
as a control parameter. There are advantages and disadvantages to both
approaches.
The "whole effluent" approach eliminates the need to specify a limit for each of
thousands of substances that may be found in an effluent. It also includes all
interactions between constituents as well as biological availability.
"The species of Ceriodaphnia used for this study is not known with certainty. The stocks were thought to be C.
retioulata but, in November 1983, based on taxonomic verification by Dorothy Berner, Ph.D. (Temple University,
Pa.), a second species, C. dubia was also discovered in the stock cultures. The exact determination of the species
tested is not critical to this study, and all reference is to the genus in this report.
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This report presents the site study on the Naugatuck River, Waterbury,
Connecticut, which was conducted in August 1983. The Naugatuck River
receives industrial discharges from tributaries and direct discharges from
publicly owned treatment works.
To date, eight sites involving municipal and industrial dischargers have been
investigated. They are, in order of investigation:
1. Scippo Creek, Circleville, Ohio
2. Ottawa River, Lima, Ohio
3. Five Mile Creek, Birmingham, Alabama
4. Skeleton Creek, Enid, Oklahoma
5. Naugatuck River, Waterbury, Connecticut
6. Back River, Baltimore Harbor, Maryland
7. Ohio River, Wheeling, West Virginia
8. Kanawha River, Charleston, West Virginia
This project is a research effort only and has not involved either NPDES permit
issuance or enforcement activities.
Rick Brandes
Permits Division
• Nelson Thomas
ERL/Duluth
Project Officers
Complex Effluent Toxicity
Testing Program
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Contents
Page
Foreword jjj
List of Figures
List of Tables
Acknowledgments
List of Contributors ,
Executive Summary
Quality Assurance
1. Introduction 1-1
2. Study Design 2-1
2.1 Toxicity Tests 2-1
2.2 Field Survey 2-1
2.3 Approach to Integration of Laboratory and
Field Data 2-2
3. Site Description 3-1
4. Onsite Tests for Toxicity of Effluents and
Receiving Water 4-1
4.1 Chemical/Physical conditions 4-1
4.2 Ambient Tests 4-2
4.3 Effluent Tests 4-5
5. Offsite Tests for Toxicity of Effluents and
Receiving Water > 5-1
5.1 Chemical/Physical Conditions 5-1
5.2 Toxicity Test Results 5-1
6. Hydrological Survey 6-1
6.1 Naugatuck River and Discharge Flow Measurements 6-1
6.2 Dilution Analysis of Naugatuck POTW 6-3
6.3 Dilution Analysis of Waterbury POTW 6-4
6.4 Dilution Analysis of Steele Brook 6-6
6.5 Evaluation of Dilution Characteristics 6-7
7. Periphytic Community 7-1
7.1 Community Structure 7-1
7.2 Chlorophyll a and Biomass 7-3
7.3 Evaluation of Periphytic Community Response 7-3
7.4 Periphyton Community Summary 7-6
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Contents (cont'd)
Page
8. Crustacean Zooplankton Community 8-1
8.1 Community Composition 8-1
8.2 Evaluation of Community Response 8-1
9. Benthic Macroinvertebrate Community 9-1
9.1 Community Structure 9-1
9.2 Differences Between Stations 9-3
9.3 Station Comparisons of the Number of Benthic Taxa 9-6
9.4 Evaluation of the Macroinvertebrate Community 9-9
10. Fish Community ....10-1
10.1 Community Structure 10-1
10.2 Evaluation of Fish Community Response 10-2
11. Comparison of Laboratory Toxicity Data and
Receiving Water Biological Impact 11-1
11.1 Background 11-1
11.2 Comparison of Toxicity and Field Data for
Naugatuck River 11-2
11.3 Summary : 11-4
References R-1
Appendix A: Onsite Toxicity Test and Analytical Methods A-1
Appendix B: Offsite Toxicity Test and Analytical Methods B-1
Appendix C: Hydrological Sampling and Analytical Methods C-1
Appendix D: Biological Sampling and Analytical Methods D-1
Appendix E: Onsite Toxicological Data E-1
Appendix F: Offsite Toxicological Data F-1
Appendix G: Biological Data G-1
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List of Figures
Number Title Page
3-1 Study area of the Naugatuck River 3-3
6-1 Hourly USGS flows at Beacon Falls on the Naugatuck River and
the discharge flow from the Waterbury POTW 6-3
6-2 Dilution contours in the Naugatuck River downstream from the
Naugatuck POTW, 23 August 1983 f 6-5
6-3 Dilution contours in the Naugatuck River downstream from the
Waterbury POTW, 25 August 1983 6-6
6-4 Surface dilution contours in the Naugatuck River downstream from
Steele Brook, 27 August 1983 6-8
6-5 Mid/bottom dilution contours in the Naugatuck River
downstream from Steele Brook, 27 August 1983 6-8
6-6 Flow contributions to the Naugatuck River from natural sources,
POTWs, and other dischargers 6-10
7-1 Spatial variations in periphyton standing crop, diversity, and
Autotrophic Index in the Naugatuck River and selected tributary
stations, August 1983 7-4
7-2 Spatial variations in absolute and relative abundance of major
taxonomic groups and selected periphytic taxa in the
Naugatuck River, August 1983 : 7-5
7-3 Spatial variations in periphyton standing crop, diversity,
Autotrophic Index, and densities of selected taxa within the
Mad River drainage, August 1983 7-7
8-1 Spatial variation in crustacean zooplankton diversity and
density in the Naugatuck River, August 1983 8-3
9-1 Spatial comparison of benthic community parameters 9-1
9-2 Spatial trends in abundance of Trichoptera and Ephemeroptera and
predominant trichopteran genera in the Naugatuck River 9-8
9-3 Spatial trends in abundance of Chironomidae and Oligochaeta and
predominant chironomid species groups in the Naugatucck River .. 9-8
9-4 Nonlinear regression of the number of benthic taxa on flow 9-9
9-5 Residuals versus river flow 9-10
10-1 Abundance and number of species of fish captured from the
Naugatuck River, Connecticut 10-3
10-2 Number offish captured in the Mad River, Connecticut 10-4
11-1 Toxicity of ambient station water to fathead minnows
and Ceriodaphnia, Naugatuck River '. 11-3
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List of Figures (cont'd)
Number
Title
Page
11-2 Number of fish and periphyton taxa at the various stream stations,
Naugatuck River 11-3
11-3 Number of benthic and zooplankton taxa at various stream stations,
Naugatuck River 11-4
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List of Tables
Number Title page
13-1 Naugatuck River and tributary stations descriptions 3-2
4-1 Mean individual weights and survival of larval fathead minnows
exposed to ambient toxicity tests, Naugatuck River, Waterbury,
Connecticut 4.0
4-2 Mass balance Ceriodaphnia toxicity test run with ambient
samples collected from the Naugatuck River, Waterbury,
Connecticut 4.3
4-3 Mean young production and percent survival of Ceriodaphnia
impact station toxicity test, Naugatuck River, Waterbury,
Connecticut ' 4_g
4-4 Seven-day percent survival of larval fathead minnows exposed
to various concentrations of three POTW effluents, Naugatuck
River, Waterbury, Connecticut 4.5
4-5 Seven-day percent survival of larval fathead minnows exposed
to various concentrations of two tributary water dilution tests,
Naugatuck River, Waterbury, Connecticut ' 4.5
4-6 Mean individual weights of larval fathead minnows exposed to
various concentrations of three POTW effluents, Naugatuck
River, Waterbury, Connecticut 4.7
4-7 Mean individual weights of larval fathead minnows exposed to
various concentrations of two tributary water dilution tests,
Naugatuck River, Waterbury, Connecticut 4.7
5-1 Results of offsite Phase I Ceriodaphnia toxicity tests with the
Gulf Stream sample, Naugatuck River 5-2
5-2 Results of offsite Phase I Ceriodaphnia effluent dilution toxicity
tests with the Torrington POTW, Naugatuck River 5-3
5-3 Results of offsite Phase I Ceriodaphnia effluent dilution toxicity
tests with the Thornaston POTW, Naugatuck River 5.4
5-4 Results of offsite Phase I Ceriodaphnia toxicity tests with the
Steele Brook sample, Naugatuck River 5.5
5-5 Results of offsite Phase I Ceriodaphnia toxicity tests with the
Great Brook sample, Naugatuck River 5-6
5-6 Results of offsite Phase I Ceriodaphnia toxicity tests with the
Mad River samples, Naugatuck River 5.7
5-7 Results of offsite Phase I Ceriodaphnia toxicity tests with
Station N8 samples, Naugatuck River 5.3
ix
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Number
List of Tables (cont'd)
Title
Page
5-8 Results of offsite Phase I Ceriodaphnia ambient toxicity'tests at
Stations N9 and N10, Naugatuck River 5-9
5-9 Results of offsite Phase II Ceriodaphnia effluent dilution
toxicity tests with the Naugatuck POTW, Naugatuck River 5-10
5-10 Results of offsite Phase II Ceriodaphnia effluent dilution
toxicity tests with the Waterbury POTW, Naugatuck River 5-11
5-11 Results of offsite Phase II Ceriodaphnia ambient station dilution
toxicity tests with Station N8 samples, Naugatuck River 5-12
5-12 Results of offsite Phase II Ceriodaphnia Waterbury POTW and
N8 mixture effluent dilution toxicity tests, Naugatuck River 5-13
5-13 Results of offsite Phase II Ceriodaphnia Naugatuck POTW and
N9 mixture effluent dilution toxicity tests, Naugatuck River 5-14
5-14 Results of offsite Phase II Ceriodaphnia ambient station toxicity
tests at Stations N9 and N10, Naugatuck River 5-15
5-15 Summary of offsite Ceriodaphnia toxicity tests acceptable
effluent concentrations (AEC's) 5-15
6-1 Flows measured at biological sampling and USGS stations on
the Naugatuck River 6-2
6-2 Daily mean, minimum, and maximum discharges at the
Waterbury POTW and Naugatuck POTW 6-2
6-3 Results of the time-of-travel studies performed by the State of
Connecticut 6-4
6-4 Average Naugatuck River flow and percent flow contribution
from three discharges for the period 22-26 August 1983 6-10
7-1 Chlorophyll a and biomass data and statistical results for
periphyton collected from natural substrates in the Naugatuck
River, August 1983 7-1
7-2 Chlorophyll a and biomass data and statistical results for
periphyton collected from natural substrates in the tributaries
to the Naugatuck River, August 1983 7-2
8-1 Percent abundance and occurrence of crustacean zooplankton
taxa collected from the Naugatuck River and tributaries,
25-27 August 1983 8-2
8-2 Density of crustacean zooplankton at sampling stations from
the Naugatuck River, 25-27 August 1984 8-2
8-3 Density of crustacean zooplankton taxa at samplilng stations
along tributaries of the Naugatuck River, 25-27, August 1983 8-4
9-1 Average density of the most abundant species at each sampling
station, Naugatuck River and tributaries, August 1983 9-2
9-2 Density and percent composition of major benthie taxa
collected from the Naugatuck River and tributaries, August 1983 .. 9-7
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Number
List of Tables (cont'd)
Title
Page
10-1 Numbers of fish collected from the Naugatuck River and
tributaries in Connecticut, 1983 10-2
11-1 Percent increase in toxicity and reduction in taxa for each
ambient station using the least toxicity or largest number of
taxa as zero percent 11-5
11-2 Comparison of toxicities with instream impact using four
different levels of effect 11-5
C-1 Transect locations for dye studies at three sites on the Naugatuck
River in August 1983 C-2
D-1 Dimensions of pool and riffle habitat at each sampling station D-2
E-1 Routine chemistry data for effluent dilution toxicity tests,
Naugatuck River, Waterbury, Connecticut E-1
E-2 Routine chemistry data for ambient station toxicity tests,
Naugatuck River, Waterbury, Connecticut E-2
E-3 Hardness, alkalinity, and turbidity measurements for the
ambient stations, the two tributary samples and the three
POTW's tested, Naugatuck River, Waterbury, Connecticut E-2
E-4 Final dissolved oxygen measurements for Ceriodaphnia impact
station toxicity tests, Naugatuck River, Waterbury, Connecticut.... E-2
E-5 Final dissolved oxygen measurements for Ceriodaphnia mass
balance test, run with ambient samples collected from the
Naugatuck River, Waterbury, Connecticut E-2
F-1 Ranges in water quality parameters for ambient stations,
tributaries, and effluent samples, Naugatuck River F-1
4
F-2 Measured water quality parameters during offsite Ceriodaphnia
toxicity tests F-2
F-3 Results of preliminary methodological variability tests with
Ceriodaphnia and Waterbury POTW effluent dilution tests F-4
F-4 Summary of preliminary methodological variability tests F-4
G-1 Abundance and diversity of periphytic algae on natural
substrates in the Naugatuck River, August 1983 G-1
G-2 Abundance and diversity of periphytic algae on natural
substrates in Gulf Stream, Steele Brook, Beaver Pond Brook,
and Mad River, August 1983 G-2
G-3 Crustacean zooplankton species collected from the Naugatuck
River, 25-27 August 1983 G-3
G-4 Taxonomic list of benthic macroinvertebrates collected from a
qualitative sampling effort in the Naugatuck River and
tributaries, September 1983 G-4
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Number
G-5
List of Tables fcont'd)
Title
Page
Ranked abundance listing of all macroinvertebrates collected
from Naugatuck River, August 1983 Q-5
Shannon-Wiener diversity-indices and associated evenness
redundance values for the benthic macroinvertebrates from
the Naugatuck River and tributaries, September 1983 G-8
List offish species and families collected from the Naugatuck
River and tributaries, Connecticut G-9
Analysis of variance and Tukey's Studentized Range Test results
for major benthic groups, Naugatuck River, August 1983 G-9
Analysis of variance and Tukey's Studentized Range Test results
for genera of Hydropsychidae, Naugatuck River, August 1983 G-10
G-10 Analysis of variance and Tukey's Studentized Range Test results
for species of Cricotopus, Naugatuck River, August 1983 G-11
G-6
G-7
G-8
G-9
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A cknowledgments
Our appreciation to Floyd Boettcher, Environmental Research Laboratory—
Duluth, Minnesota, as field engineer and the assistance of Scott Heinritz, ERL-
Dliluth, during the toxicity testing is acknowledged. The local arrangements,
sample collection and general guidance in establishing sampling locations was
provided by personnel from the State of Connecticut. We truly appreciate their
help. Finally, we are indebted to the EPA Region I personnel who assisted in the
study site selection, pre-site visits, and other details of the study.
XIII
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List of Contributors
ONSITE TOXICITY TESTS
Donald I. Mount1 and Dennis McCauley2
OFFSITE TOXICITY TESTS
Wayne L McCulloch3 and Nancy J. Belinko3
HYDROLOGICAL SURVEY
Jonathan C. Yost3
PERIPHYTIC COMMUNITY
Ronald J. Bockelman3
CRUSTACEAN ZOOPLANKTON COMMUNITY
Michael A. Hansen3
BENTHIC MACROINVERTEBRATE COMMUNITY
Michael T. Barbour3
FISH COMMUNITY
David A. Mayhew3
COMPARISON OF LABORATORY TOXICITY DATA AND
RECEIVING WATER BIOLOGICAL IMPACT
Donald I. Mount1, Nelson A. Thomas1, and Teresa J. Norberg-King1
PRINCIPAL INVESTIGATOR: Donald I. Mount1
'Environmental Research Laboratory, U.S. Environmental Protection Agency, 6201 Congdon Blvd., Duluth, MN
55804.
'Center for Lake Superior Environmental Studies, University of Wisconsin-Superior, Superior, Wl 54880.
3EA Engineering, Science, and Technology, Inc., Hunt Valley/Loveton Center, 15 Loveton Circle, Sparks, MD
21152,
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Executive Summary
This report presents part of a larger study conducted on the Naugatuck River,
Connecticut, August 1983. In addition to the studies described here, there is
another report describing efforts to model the toxicity as BOD is modeled (DiToro
and Hallden, 1985) and a site-specific single chemical criterion study (Carlson et
al., 1986).
The major purpose of the study described here was to compare the relationship
between measured toxicity of water samples collected from the Naugatuck River
and the health of the aquatic community at the same locations where samples
were collected. Because the river changed in size and character through the
study area, habitat changes made the determination of toxicity effects on the
stream community more difficult. Periphyton, benthos and fish species all
showed a trend of reduced species richness from headwaters to mouth. The
Ceriodaphnia and fathead minnow toxicity data show a similar trend. The
zooplankton taxa did not follow an upstream downstream pattern. An impound-
ment and the large difference in stream size between N-1 andN-12 may account
for part of the difference.
The effluent dilution tests were not performed in a manner that they could be
used to predict impact because they were to be used for a mass balance model of
toxicity and the needs for that purpose were different. When toxicity and species
richness were converted to normalized percent values and compared at four
levels of impairment, up to 85% correct predictions were achieved. Significant
correlations (P < 0.05) were obtained with the Ceriodaphnia data and the
periphyton, macroinvertebrate, and fish species richness.
Even though a number of factors such as stream size and gradient changed
through the study area, there were significant correlations of the field impact
and toxicity data.
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Quality Assurance
Coordination of the various studies was completed by the principal investigator
preceding and during the onsite work. A reconnaissance trip was made to the site
before the study and necessary details regarding transfer of samples, specific
sampling sites, dates of collections, and measurements to be made on each
sample were delineated. The evening before the study began, a meeting was held
onsite to clarify again specific responsibilities and make last minute adjustments
in schedules and measurements. The mobile laboratory was established as the
center for resolving problems and adjusting of work schedules as delays or
weather affected the completion of the study plans. The prinicipal investigator
was responsible for all Quality Assurance-related decisions onsite.
All instruments were calibrated by the methods specified by the manufacturers.
For sampling and toxicity testing, the protocols described in the referenced
published reports were followed. Where identical measurements were made in
the field and laboratory, both instruments were cross-calibrated for consistency.
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/. Introduction
The focus of water pollution control in the National
Pollutant Discharge Elimination System (NPDES)
permits program has been on the attainment of
national technology requirements andthe implemen-
tation of water quality criteria for the 129 priority
pollutants. However, implementation of these stand-
ards and criteria does not always guarantee that
certain dischargers will not cause adverse effects to
receiving waters. Industrial and municipal effluents
often contain large numbers of potentially toxic
pollutants which can move through treatment sys-
tems virtually unaltered. Often these are pollutants
for which little or no toxicity data exist. Further
complications arise from the potential interaction of
combinations of pollutants to increase or decrease
toxicity.
Future activities in water pollution control will focus
on the control of toxic pollutants which impact water
quality. There are two methods used in controlling
toxic impact: pollutant-specific controls and whole
effluent toxicity-based controls. Because toxicity
testing evaluates a living organism's response, it has
an advantage over chemical-specific analyses which
may not identify all pollutants in a wastewater sample
and which cannot detect toxicity interactions. Toxicity
information can indicate the need for additional
characterization of an effluent and can also provide a
basis for permit limits based on state water quality
standards for toxicity- or technology-based require-
ments.
The primary purpose of this study is to investigate the
relationship between ambient toxicity data and
ecological response and to attempt a mass balance
model of toxicity.
This report is organized into sections corresponding
to the project tasks. An Executive Summary is
presented after the Foreword as a brief overview of
the major findings of this study. Following a descrip-
tion of the study design and a summary of the site, the
chapters are arranged into toxicity testing, hydrology,
ecological surveys for the study period, and an
integration of the laboratory and field studies. Addi-
tional laboratory methods and support data are
included in the appendixes.
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2. Study Design
The primary purpose of this study was to investigate
the ability of laboratory effluent toxicity tests to
predict ambient stream toxicity impacts at a multiple
discharge site on a medium-size river system. The
site chosen for study was the Naugatuck River from
Torrington to Ansonia, Connecticut. The study area
included multiple discharges: several industrial dis-
chargers on each of four tributaries and four major
publicly owned treatment works (POTWs) located on
the mainstem. A more complete description of the
study area is in Chapter 3. This study required
laboratory tests to measure expected effluent dilu-
tions that would be safe for chronic exposure. In
conjunction with these toxicity tests, ecological
surveys of the Naugatuck River and its tributaries
were conducted to identify structural effects to
representative biotic communities and selected pop-
ulations from point source discharges. Hydrological
analyses included effluent configuration studies to
define mixing characteristics of some of the effluents.
Frequent flow measurements were taken at selected
locations along the river to estimate effluent concen-
trations and to provide support data for mass balance
calculations. The results from all of these study
components were then integrated.
The study was conductedfrom 23 through 30 August
1983. The methods used inJhe study are detailed in
Appendixes A, B, C, and D/Support toxicological and
biological data are included in Appendixes E, F, and G.
2.1 Toxicity Tests
Toxicity tests were performed both onsite and at a
remote laboratory. The objectives of these tests were
to measure the Acceptable Effluent Concentration
(AEC) of effluents or tributaries and the toxicity of
undiluted ambient river samples.
For the onsite tests, both the 7-day fathead minnow
larval growth test and the 7-day Ceriodaphnia
reproduction test were used (Chapter 4). For the
fathead minnow tests, 24-hour composite samples
were taken of effluent and ambient samples and the
test animals exposed for 24 hours. Then a new 24-
hour composite was used for the renewal.
For the Ceriodaphnia tests, similar types of ambient
tests were done using the same samples as for the
fathead minnow tests. These were called "impact"
type tests. In addition, another type, named "mass-
balance" type tests, were done for a mass-balance
toxicity model. In these tests, each sample was kept at
4°Cand used to renew the test solutions which were
changed only at the end of days 2 and 4 and were not
changed daily. Thus, there were 7 separate chronic
tests, each completed on a different 24-hour com-
posite sample for each effluent or ambient station
tested.
In the offsite testing, only Ceriodaphnia tests on
effluents were done, i.e., no ambient tests were
attempted (Chapter 5). An aliquot of the daily 24-hour
composite eff I uent sample was shipped to the remote
laboratory in Baltimore by air freight. Mass-balance
type tests were done to establish the AEC for each
effluent or tributary tested.
2,2 Field Survey
The field survey included quantitative assessment of
the periphytic, zooplanktonic, benthic macroinverte-
brate, and fish communities. The periphyton study
measured chlorophyll a and biomass and estimated
species composition and relative abundance (Chapter
7). The relatively short reproduction time and rapid
seasonal fluctuations in growth'make the periphytic
algae community indicative of recent exposure condi-
tions.
In contrast to the more sedentary periphytic and
benthic communities, planktonic communities in lotic
systems drift downstream and do not necessarily
reflect exposure at the collection site. Crustacean
zooplankton populations were measured and used as
an indicator of planktonic community response
(Chapter 8).
The benthic survey investigated ambient community
response above and below the discharges (Chapter
9). The benthic community, measured by the methods
used in this report, is less mobile than other com-
munity groups, such as fish, and is considered an
indicator of longer term water quality trends.
The fish survey measured the fish species present
and their relative abundance to discern any com-
munity changes from previous surveys or upstream
and downstream of the discharges (Chapter 10).
Hydrological measurements were conducted using
dye studies at each of three sites to identify the
individual dilution characteristics of these effluents
2-1
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(Chapter 6). By modeling downstream dilution con-
tours for each discharge, the exposure concentrations
at various ambient stations could then be established.
Ancillary flow measurements were also taken to
estimate the flow contribution of the discharges to
the receiving waterbody.
2.3 Approach to Integration of
Laboratory and Field Data
The data from the ambient toxicity tests is compared
to the species richness at the ambient stations. Some
rationale for selecting species richness as well as the
comparisons is given.
2-2
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3. Site Description
The study area on the Naugatuck River incorporated
60 km of the river and its tributaries extending from
Torrington to Ansonia, Connecticut. Twelve main-
stem river stations and eight tributary stations were
established for sampling and testing (Table 3-1). The
Naugatuck River above Torrington was approximately
15-20 m wide and less than 0.5 m deep during the
study period. River flow measured in this area was
approximately 0.05 mVsec. Downriver, near An-
sonia, the Naugatuck River was approximately 100 m
wide and 2-3 m deep. River flow in this area was 3-4
mVsec. The river was regulated in certain reaches
nearThomaston, Seymour, and Ansonia (Figure 3-1).
Water is impounded behind the Thomaston Dam only
for flood control but there is no permanent pool
maintained there.
Several publicly owned treatment works (POTWs)
and privately owned industries discharge treated
effluents to the Naugatuck River and its tributaries.
Approximately 28 dischargers are within the study
area extending from Torrington to Ansonia, Con-
necticut (Figure 3-1). The industries are mostly small
metal refinishing facilites that discharge effluents
into tributaries of the Naugatuck River (Gulf Stream,
Steele Brook, Great Brook, and Mad River). Each of
these tributaries was treated as a point source
discharge to the Naugatuck River and samples were
tested accordingly. Four major POTWs which dis-
charge directly to the Naugatuck River were also
studied. They are the Torrington, Thomaston, Water-
bury, and Naugatuck POTWs. The waterbury POTW
contributes the largestflowto the river, averaging 0.7
mVsec during the study period. The average dis-
charges for the other POTWs were 0.2 mVsec for the
Naugatuck POTW and less than 0.1 mVsec for the
Torrington and Thomaston POTWs. The Mad River
contributed the largest flow, averaging 0.3 mVsecfor
the study period. Steele Brook had a flow of 0.1-0.2
mVsec. The flows of both Gulf Stream and Great
Brook were less than 0.1 mVsec. See Chapter 6 for a
more detailed description of river flow.
3-1
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Table 3-1. Naugatuck River and Tributary Station Descriptions
Station
Number
N1
N2
N3
N4
N4A
N5
N6
N7
N8
N9
N10
N11
N12
River
Kilometer
67.3
63.5
62.4
59.0
50.1
46.5
32.5
30.4
28.3
21.9
16.5
9.5
3.0
Station Location
Rte. 4, West Fork of Naugatuck River, West of Torrington
East Albert St. in Torrington, confluence of East and West Branch
Palmer Bridge Rd. in Torrington
Rte. 118, 0.8 to 1 .6 km downstream from Torrington
0.1 km upstream from Thomaston Dam
Frost Bridge in Thomaston (Benthos Station for State of Connecticut)
W. Main St., 1,6 km downstream of Steel Brook (Benthos-State work)
0.4 km upstream of Mad River; first bridge upstream of Washington St.
0.8 km upstream of the Waterbury POTW. First bridge upstream on
South Leonard St.
1.6 km upstream from the Naugatuck POTW Rte. 63 bridge
0.4 km upstream from USGS gauging station at Beacon Falls,
Rte. 8 bridge
Bridge immediately downstream from Rte. 8 in Seymour
Railroad bridge 0.4 km upstream from Division St. in Ansonia (Benthos
Station for State of Connecticut)
Tributaries
GS1
SB1
GB1
Ml
M2
BP1
BP2
MS
Location ofPOTWs
Torrington
Thomaston
Waterbury
Naugatuck
62.8
33.4
32.9
29.9
RK 61.2
RK 47.5
RK 27.2
RK 19.4
Gulf Stream Bridge, 0.2 km upstream from confluence with Naugatuck
River in Torrington
Steele Brook at East Aurora St. Bridge
Great Brook at confluence with Naugatuck River
Upper reaches of Mad River at Frost Road Bridge
Upstream of confluence of Mad River with Beaver Pond Brook at Main
St. Bridge
Beaver Pond Brook upstream of confluence with Mad River
Near headwaters of Beaver Pond Brook
Mad River at confluence with Naugatuck River
3-2
-------
Figure 3-1. Study area of the Naugatuck River.
West Branch \ East Branch
N1
Gulf Stream
Torrington
N4 1 T°rrm9t°n POTW
Thomaston POTW A3qi='Thomaston Dam
Thomaston
N5
Housatonic River
Mad River
BP1
Beaver Pond Brook
Beacon Hill Brook
Seymour
—x
N11 —v. Bladens River
Kilometers
02468
3-3
-------
-------
4. Onsite Tests for Toxicity of Effluents and Receiving Water
As part of a large study to assess the biological impact
of numerous discharges to the Naugatuck River,
onsite toxicity tests were conducted in a mobile lab
using samples collected from 23 to 30 August 1983.
The major objective for the onsite testing was to
measure ambient toxicity (the toxicity of water
samples collected directly from the stream) to com-
pare with the field biological test data. Effluent
dilution tests require that the effluent concentrations
in the stream be known in order to predict effects but
this information is not necessary for the ambient
tests. The sample collection and test methodologies
used for both species are delineated in Appendix A.
A second major objective in this study was to gather
information to enable construction of a mass balance
toxicity model. Changes in the toxicity testing study
design from previous sites (Mount et al. 1984, Mount
' et al. 1985) were required to facilitate the model.
Complete 7-day chronic Ceriodaphnia tests on each
of seven 24-hour composite samples were run rather
than changing the animals into a new 24-hour
composite sample every day. This procedure was
defined as the "mass balance test" to distinguish it
from another set of tests called the "impact tests."
The latter test is when the Ceriodaphnia and fathead
minnows are exposed to a different 24-hour com-
posite sample each day for seven days. Thus, the
mass balance tests generate seven estimates of
chronic toxicity for each effluent or ambient station
whereas the impact tests result in only one estimate
of chronic toxicity. The mass balance tests are best
used when the goal is to measure temporal variations
in the toxicity of effluents and ambient stream sta-
tions, and the impact tests are best when simulating
the exposure the organisms in the stream receive.
There is no known way to match the results of the two
tests to account for the different test exposures over
their respective 7-day test periods.
Mass balance tests were conducted only with the
Ceriodaphnia. Such tests are not very practical for
fathead minnows because so many test-chambers
and so much space would be required. The following
summarizes the tests done:
Ceriodaphnia
Sample
Torrington POTW
Waterbury POTW
Naugatuck POTW
Steele Brook
Mad River
N1
N2
N3
N4
N4A
N5
N6
N7
N8
N9
N10
N11
N12
Mass
Balance
0
0
0
0
0
0
X
X
X
0
X
X
X
X
X
X
0
0
Impact
0
0
0
0
0
X
0
0
X
X
0
0
0
0
0
X
X
X
. Fathead
Minnow
Impact
X
X
X
X
X
0
X
0
X
0
0
X
X
X
X
X
X
X
Note: X = tests conducted
0 = no test conducted
All Ceriodaphnia effluent dilution toxicity tests were
mass balance tests but were done on shipped samples
by an environmental consulting laboratory offsite
(Chapter 5). Aliquots of composite effluent samples
were used to do impact tests (using a new composite
sample each day) on the fathead minnows. The
impact type fish tests were done onsite in the mobile
laboratory. For the purpose of comparing the mass
balance tests to biological impact in the field, the
average of the seven Ceriodaphnia effluent tests was
used but without any knowledge as to how the
estimate compares to an impact-type test.
Two of the tributaries, i.e., Steele Brook and Mad
River, had several dischargers- on each. These
tributary waters were treated as effluents to the
Naugatuck River and dilutions were made in order to
estimate an AEC.
4.1 Chemical/Physical Conditions
Temperatures were maintained between 22 and
28°C for the duration of the tests. The weather was
very warm during the test period and the changes
observed were a result of the effects of diurnal
temperatures of the outside air on the mobile lab. The
routine water quality measurements included pH,
4-1
-------
DO, and conductivity. Conductivity measurements
ranged from 88 to 1,150//mhos/cm. The Naugatuck
POTW effluent exhibited the highest conductivity
(1,150 //mhos/cm), whereas the other POTWs and
ambient stations were mostly in the range of 153-484
pmhos/cm (Tables E-1 and E-2).
Other routine chemistries such as hardness, alka-
linity, and turbidity were made on each ambient
station, the tributaries, and the effluents. A summary
of these mean measurements is given in Table E-3.
Hardness ranged from 38 to 99 mg/L as CaCO3 in the
ambient stations, and 82 to 392 mg/L in the effluents
and tributaries. A noticeable drop in hardness
measurements was observed on day 6 (rainfall
increased flow), where all values for the ambients
were approximately half of their previous values.
Alkalinity in the ambient stations ranged from 35 to
70 mg/L. The effluents and tributaries had alkalinity
measurements of 46-151 mg/L. Turbidity measure-
ments were made daily and ranged from 0.85 to 4.7
nephlometric turbidity units (NTU) for the ambients
with the highest values of N7 and N8. Both Steele
Brook and Mad River had turbidity measurements of
about 6, whereas the effluents ranged from 4 to 6
NTU.
Prior to the test animals being placed into the test
solutions, pH and DO measurements were taken, and
again daily before the test water was renewed.
Values observed for pH ranged from 6.9 to 8.2 for the
fathead minnow and Ceriodaphnia tests (Tables E-1
and E-2). The initial DO values for both the minnow
and Ceriodaphnia tests ranged from 8.1 to 8.8 mg/L.
The final mean DO values taken early in the day, prior
to test solution renewal, ranged from 5.0 to 7.0 mg/L;
the means and ranges are given in Tables E-1 and
E-2. Some individual values in fish tests were low, as
low as 1.4 mg/L. However, experience by ERL-Duluth
(Mount and Norberg-King, 1986) has shown that
"such values do not represent the oxygen concentra-
tions the fish are actually exposed to. The fish move to
the surface and the minnows grow at a normal rate
even when the DO measured values are less than 1.0
mg/L. Tables E-4 and E-5 contain final DO values for
the Ceriodaphnia tests. All values are in the accept-.
able range.
Effluent and ambient stream samples were composite
samples with sampling done every 15 minutes.
Stations N6 and N7 were composite samples col-
lected manually every 4 hours. Due to vandalism, the
following samples were collected as grab samples on
the indicated sampling days: Station N1 was a daily
grab. Station N3 on 23,24, and 27 August, Station N4
on 28 August, Station N4A on 29 August, Station N9
on 24 August, and Station N10 on 23 August.
In the test on Steele Brook water, the fish weights for
1 percent are for six days of exposure. All fish died in
the first 24-hour period, and another group was set
up with the same lot of larval fish that were used to
start the testing for the other concentrations.
4.2 Ambient Tests
Table 4-1 contains the growth and survival data for
the fathead minnow ambient tests. The mortality at
Stations N10 and N11 occurred on days 2 and 3,
respectively, of the tests and corresponded to similar-
ly timed mortalities of the Ceriodaphnia. In the
Naugatuck POTW effluent dilution tests, all fish died
on day 2 even at 1 percent. Dead fish were also
observed downstream of Naugatuck POTW corrobor-
ating a slug of toxicity from that POTW. The Cerio-
daphnia mass balance tests (Table 5-8) also show
reasonably good survival and young production at
: Station N10 except on days 2 and 3. Stations N8, N10,
N11 and N12 all had significantly lower survival
and young production than Station N1. Station N9
was the only downstream station that had normal
growth and survival. Station N7 growth was lower,
but not significantly so, than Station N1. Survival and
growth showed about the same toxicity.
Table 4-2 and 4-3 contain the mass balance and
impact ambient toxicity data for the Ceriodaphnia.
The sample collection day (Table 4-2) is the date the
composite sample was ended. For the mass balance
tests, Stations N7 through N9 were significantly
lower than N4, the station with the highest young
production and good survival. Station N10 might have
been much higher if the slug of toxicity on days 2 and
3 had not occurred. Of the stations in the impact tests
(Table 4-3), N10, N11, and N12 were significantly
lower than N1, which was the water used for diluting
effluents. The impact test at Station N11 was also
affected by the slug of toxicity as were the mass
balance tests; mortality occurred one day later, on day
3, as compared to Station N10 where it occurred on
day 2. Both impact and mass balance tests were done
using Ceriodaphnia on Stations N4 and N10. The slug
of toxicity showed up at Station N10in both tests but
it made a comparison meaningless. The mean
number of young per female for the seven mass
balance tests at Station N4 is almost identical to the
mean measured for the same station in the impact
tests. Survival was similar also. Correspondence
between the results of the two types of tests would be
expected whenever variability from day to day is
small.
Because the various industries discharge only on a
5-day per week schedule, the results'of the Cerio-
daphnia mass balance reproductivity tests were not
expected to be the same over the duration of the tests
at many stations. Such variation is inherent in
effluent toxicity testing. If one uses the mean
young/female of the seven mass balance tests as an
estimate of an "impact" value that would have been
obtained as well as the data in Table 4-3, the results
4-2
-------
Table 4-1. Mean Individual Weights (mg) and Survival of Larval Fathead Minnows Exposed to Impact Ambient Toxicity Tests,
Naugatuck River, Waterbury, Connecticut
Stream
Station
N2
N4
N6
N7
N8
N9
N10
N11
N12
Replicate
A
0.35
0.47
0.35
0.31
0.10
0.31
--
_-
0.13
B
0.37
0.40
0.33
0.29
—
0.36
--
—
0.17
C
Weights (mg)
0.30
0.44
0.40
0.26
0.18
0.36
-.
0.17
D
0.31
0.39
0.43
0.29
..
0.38
__
__
0.15
Mean3
0.334
0.424
0.374
0.289
0.1 23b
0.352
b
b
0.157"
SE
0.027
0.025
0.025
0.025
0.041
0.025
__
..
0.034
N2
N4
M6
N7
N8
N9
N10
N11
N12
80
90
100
100
10
100
0
0
, 60
90
100
100
100 .
0
80
0
0
70
Survival (%)
60
100
90
80
40
100
0
0
60
100
100
80
100
0
90
0
0
20
83
98
93
95
12"
93
0"
0"
53"
"The mean weight of fish is given as a weighted mean and mean survival is expressed as mean percent.
"Significantly lower from N1 (Table 4-6) using the two-tailed Dunnett's test(P <0.05).
Table 4-2. Mass Balance Ceriodaphnia Toxicity Test Run with Ambient Samples Collected from the Naugatuck River,
Waterbury, Connecticut
Station
Number
N2
Mean
N3
Mean
'N4
Mean
Sample
Collection
Day
23 Aug
24Aug
25 Aug
26 Aug
27 Aug
28 Aug
29 Aug
23 Aug
24 Aug
25 Aug
26 Aug
27 Aug
28 Aug
29 Aug
23 Aug
24 Aug
25 Aug
26 Aug
27 Aug
28 Aug
29 Aug
Mean Number
of Young
per Female
15.0
19.6
17.1
15.6
21.9
18.4
17.8
17.9
15.3
16.5
14.2
16.7
17.1
7.2
17.0
14.9
13.5
17.0
16.2
20.9
24.3
25.0
13.1
18.6
Confidence
Intervals
12.3-17.7
16.6-22.5
13.3-20.9
13.6-17.6
19.5-24.2
14.3-22.5
16.1-19.5
(SD 2.4)"
13.0-17.6
13.3-19.8
11.2-17.2
12.2-21.2
14.7-19.6
5.5-8.9
14.0-20.0
(SD 3.5)
9.8-17.2
14.9-19.2
11.3-21.0
18.2-23.6
19.9-28.7
20.7-29.3
11.0-15.2
(SD 4.9)
Mean
Percent
Survival
60
100
90
100
90
80
100
87
100
80
100
90
90
50
100
87
70
90
60
90
100
100
90
86
4-3
-------
Table 4-2 (Continued)
Sample
Station Collection
Number Day
N5 23 Aug
24Aug
25Aug
26Aug
27Aug
28Aug
29Aug
Mean
N6 23 Aug
24Aug
25 Aug
26 Aug
27 Aug
28 Aug
29 Aug
Mean
N7 23 Aug
24 Aug
25 Aug
26 Aug
27 Aug
28 Aug
29 Aug
Mean
N8 23 Aug
24 Aug
25 Aug
26 Aug
27 Aug
28 Aug
29 Aug
Mean
N9 23 Aug
24 Aug
25 Aug
26 Aug
27 Aug
28 Aug
29 Aug
Mean
N10 23 Aug
24 Aug
25 Aug
26 Aug
27 Aug
28 Aug
29 Aug
Mean
Mean Number
of Young
per Female
18.2
17.6
15.7
17.3
19.9
17.4
16.3
17.5
4.0
7.0
15.6
15.3
21.4
18.1
20.4
14.5
15.1
0
—
—
—
21.0
18.4
7.8"
.-
—
—
—
—
6.5
—
1.2"
15.4
9.2
13.2
5.9
4.7
4.5
11.9
9.3"
10.0
—
—
19.9
21.5
14.4
12.9
11.3
Confidence
Intervals
14.6-21.8
15.2-20.1
12.5-18.9
14.9-19.7
16.3-23.5
15.3-19.6
1 2.2-20.4
(SD 1 .4)
—
3.3-10.6
12.3-19.0
12.5-18.0
16.4-26.4
1 5.7-20.5
1 6.8-24.0
(SD 6.6)
8.8-21.4
--
—
—
—
16.9-25.1
13.3-23.5
(SD 9.9)
—
—
—
—
—
0-21.1
-
(SD 2.4)
' 0-40.6
5.5-12.8
11.3-15.1
3.2-8.5
3.5-5.8
2.8-6.3
9.9-13.9
(SD 4.4)
5.6-14.4
—
—
16.6-23.2
18.9-24.1
11.7-17.2
9.8-16.1
(SD 8.6)
Mean
Percent
Survival
90
80
100
90
100
90
100
93
0
80
70
70
90
100
100
73
50
10
0
0
0
70
80
30
0
0
0
0
0
78
0
11
20
70
80
30
0
50-
100
50
67
0 .
0
100
100
90
89
64
"Significantly lower than Station N4 (P < 0.05).
"Standard deviation.
4-4
-------
Table 4-3.
Mean Young Production and Percent Survival of Ceriodaphnia Impact Ambient Station Toxicity Test, Naugatuck
River, Waterbury, Connecticut
Stream
Station
N1ab
N1b
N1c
N4
N4A
N10
N11
N12
Mean Number
of Young
per Female
19
'12
17
.1
.6
.2
18.5
14
—
--
—
.1
a
a
a
Confidence
Intervals
14.3-24.0
8.4-16.8
13.0-21.4
15.2-21.8
10.1-18.1
—
..
--
Day of Test
1
100
90
100
90
100
89
80
0
2
100
90
100
90
100
0
80
0
3
90
90
90
80
100
0
0
0
4
90
90
90
80
100
0
0
0
5
90
90
90
80
100
0
0
0
6
90
90
90
80
100
0
0
0
7
90
90
90
80
100
0"
0'
0'
"Significantly lower than Station Ml (P < 0.05).
ba, b, and c were replicates of Station N1 water.
show impact at Stations N7 through N12. The fathead
minnowtestsshowtoxicityatStations N8, N10, N11,
and N12. The Ceriodaphnia test results for Station N7
and N9 showed toxicity while no toxicity was observed
in the fathead minnow tests for those stations.
4.3 Effluent Tests
The Ceriodaphnia effluent test data are found in
Chapter 5 as they were conducted in a different
location and manner (mass balance) than the fathead
minnow effluent tests (impact tests).
The fathead minnow survival data for the effluent
tests are given in Tables 4-4 and 4-5, and the weight
data are given in Tables 4-6 and 4-7. The Torrington
POTW gave an atypical dose response curve which
has been seen on other occasions (Mount et al. 1984)
but usually in the Ceriodaphnia tests rather than the
fathead minnow tests. An AEC cannot be obtained
from such data. The effect/no-effect levels were 100
and 30 percent, respectively, for the Waterbury
POTW, and the AEC estimate (which is the geometric
mean of the no observed effect concentration (NOEC)
and lowest observed effect concentration [LOEC]) is
54.7 percent. The toxic concentration of the Nauga-
tuck POTW effluent was determined by a toxic slug
(within 48 hours) that put the AEC (attributed to
the slug of toxicity) at less than 1 percent. The sample
of the Naugatuck POTW was tested two days later at
the 10 percent level using 3-day-old fathead min-
nows. All fish were dead in less than 24 hours. The
AEC for Steele Brook is 1.7 percent and for Mad River
it is less than 1 percent. From Tables 6-4, Steele
Brook made up 15.7 percent of the flow in the
Naugatuck at Station N6 and 14.8 percent at Station
N7, but there was no ambient toxicity found even
though the AEC was 10-fold less. The Mad River
makes up over 20 percent of the flow at Station N8
(Figure 6-6J and the AEC for the Mad River was less
than 1 percent. Toxicity was observed at Station N8
but not as dramatic as might be expected based on the
Mad River dilution test. The explanation undoubtedly
lies in the dilution water used for the effluent tests,
i.e.. Station N1 water. That dilution water does not
contain effluents, especially POTW effluent, whereas
the dilution water for the Steele Brook and Mad River
does. In numerous other studies of receiving streams,
we have observed mixtures of effluents which exhibit
markedly less toxicity thaa would occur by simple
addition of the effluents. Further evidence is provided
by Carlson et al. (1986) in which they showed the
toxicity of copper to be greatly reduced in Station N6
water as compared to Station N1 water. Likewise,
below the Waterbury POTW at Station N9 where the
Mad River still composes over 10 percent of the flow
(Figure 6-6), no toxicity was evident. Based on
experience at other locations and the copper toxjcity
data described by Carlson, et al., the lesser toxicity is
to be expected.
4-5
-------
Table 4-4. Sevan-Day Percent Survival of Larval Fathead Minnows Exposed to Various Concentrations of Three POTW Effluents,
Naugatuck River, Waterbury, Connecticut
Percent Effluent (v/v)
Effluent
by Replicate
Torrington POTW
A
B
C
D
Mean
Waterbury POTW
A
B
C
D
Mean
Naugatuck POTW
A
B
C
D
Mean
100
90
100
60
80
83
80
60
80
10
58"
0
0
0
0
0"
30
100
100
100
90
98
100
90
90
100
95
0
0
0
0
Ob
10
30.
70
20
30
38"
90
90
90
100
93
0
0
0
0
0"
3
60
90
70
40
65"
100
80
100
90
93
0
0
0
0
Ob
1
30
10
0
20
15"
90
100
90
100
95
0
0
0
0
Ob
Dilution
Water0
„
—
95°
100
90
100
90
95'
__
__
__
95b
"N1 water was used as dilution water for each POTW effluent dilution test.
"Significantly lower from N1 using the two-tailed Dunnett's test (P < 0.05):
Table 4-5.
Seven-Day Percent Survival of Larval Fathead Minnows Exposed to Various Concentrations of Two Tributary Water
Dilution Tests, Naugatuck River, Waterbury, Connecticut
Percent Tributary Water (v/v)
Sample by
Replicate
Steele Brook
A
B
C
D
Mean
Mad River
A
B
C
D
* Mean
100
10
0
30
0
10b
10
30
0
30
18b
30
0
0
0
0
0"
40
30
0
0
18"
10
30
50
60
30
43"
70
70
90
90
80
3
10
70
80
90
63
60
10
60
40
43"
1
100
100
100
90
98
60
40
70
30
50b
Dilution
Water0
67
90
90
90
84
80
90
100
100
93
"N1 water was used as dilution water for each test.
"Significantly lower from N1 using the two-tailed Dunnett's test (P < 0.05).
4-6
-------
Table 4-6. Mean Individual Weights (mg) of Larval Fathead Minnows Exposed to Various Concentrations of Three POTW
Effluents, Naugatuck River, Waterbury, Connecticut
Percent Effluent (v/v)
Effluent
by Replicate
Torrington POTW
A
B
C
D
Weighted Mean
SE
Waterbury POTW
A
B
C
D
Weighted Mean
SE
Naugatuck POTWd
A
B
C
D
Weighted Mean
SE
100
0.29
0.33
0.27
0.30
0.307
0.027
0.18
0.20
0.20
0.20
0.193°
0.034
--
—
—
--
C
30
0.34
0.34
0.38
0.38
0.360
0.025
0.38
0.31
0.30
0.31
0.326
0.027
--
--
—
--
C
10
0.17
0.20
0.20
0.17
0.188°
0.040
0.32
0.30
0.33
0.31
0.315
0.027
--
—
--
—
C
3
0.23
0.26
0.26
0.23
0.248°
0.030
0.36
0.33
0.32
0.37
0.345
0.027
*
—
—
--
C
1
0.13
0.30
—
0.25
0.198
0.063
0.36
0.46
0.33
0.32
0.369
0.027
—
--
--
--
C
Dilution
Water'
--
—
—
—
0.341"
0.016
0.38
0.40
0.40
0.47
0.341"
0.016
~"
—
__
—
0.341 b
0.016
"N1 water was used as dilution water for each POTW effluent dilution test.
"Value is a pooled weighted mean of all N1 dilution water weight data and used as basis for statistical comparisons.
"Significantly lower from N1 using the two-tailed Dunnett's test(P <0.05).
dThe fish died early in test and therefore no weight data were obtained.
Table 4-7. Mean Individual Weights (mg) of Larval Fathead Minnows Exposed to Various Concentrations of Two Tributary Water
Dilution Tests, Naugatuck River, Waterbury, Connecticut
Percent Effluent (v/v)
Sample by
Replicate
Steele Brook
A
B
C
D
Weighted Mean
SE
Mad River
A
B
C
D
Weighted Mean
SE
100
0.30
0.13
0.173°
0.087
0.10
0.20
0.10
0.143°
0.062
30
__
__
—
--
C
0.20
0.20
__
--
0.200°
0.062
10
0.27
0.20
0.18
0.23
0.211°
0.042
0.27
0.20
0.23
0.29
0.249°
0.029
3
--
0.27
0.22
0.24
0.242°
0.035
0.35
0.30
0.33
0.30
0.328
0.040
1
0.34
0.29
0.36
0.33
0.330
0.042
0.23
0.20
0.29
0.23
0.245°
0.036
Dilution
Water'
0.35
0.33
0.37
0.33
0.341 "
0.01 6
0.33
0.28
0.22
0.24
0.341"
0.016
"N1 water was used as dilution water for each test.
"Value is a pooled weighted mean of three N1 dilution water replicates.
"Significantly lower from N1 using the two-tailed Dunnett's test (P < 0.05).
4-7
-------
-------
5. Off site Tests for Toxicity of Effluents and Receiving Water
Toxicity tests offsite were conducted 24 August to 13
September using only Ceriodaphnia. The majority of
the offsite tests were mass balance tests as described
in Chapter 4, where seven estimates of chronic
toxicity are generated. Testing was done on four
POTWs, Station N8 and four tributary streams and
some combinations of two. All these tests were run as
effluent dilution tests in order to estimate an Accept-
able Effluent Concentration (AEC). Effluent dilution
tests were run on two POTWs which were mixed with
the stream water from directly above the discharge.
All other tests used N1 water as the diluent for
purposes of the model. Ambient testing on Stations
N9 and N10 were done during Phase I ancl Phase II, as
were Station N8 dilution tests. A description of the
testing program, sampling methods, and analytical
methods is presented in Appendix B. Routine chemi-
cal data on the ambient stations and effluent dilution
tests are in Appendix F, as well as preliminary
methodological variability test results.
The overall objective of this part of the toxicity testing
program was to investigate whether ambient toxicity
can be predicted from the results of laboratory
effluent toxicity tests used in conjunction with
measured flow data in a mass balance model. The
principle of mass balance required that effluents be
diluted in N1 water. This, however, is not the same
water quality in which the effluents are discharged in
the stream and so this aspect could not be examined
using the mass balance model approach. The model
results are being published by DiToro and Hallden
1985.
5.1 Chemical/Physical Conditions
Tables F-1 and F-2 contain the water quality measure-
ment data for the tests. Conductivity, alkalinity, and
hardness varied with station or effluent. All of these
values and pH and D.O. are within acceptable limits for
the test species. Temperatures were cpnsistently
under 25°C. Because of the large number of tests,
constant temperature cabinets were not available.
The lower temperature resulted in only two broods in
many instances". Hamilton (1984) noted that the data
he examined suggested that two broods were suf-
ficient for test purposes, so that the data generated
offsite may be adequate for purposes here.
5.2 Toxicity Test ResuIts
The results of Phase I offsite Ceriodaphnia toxicity
testsaregiven inTables5-1 to 5-7. Each test was run
for seven days and the renewal of the test solutions
were made with the same sample of effluent or
tributary water used to start each test. Ambient
station toxicity tests using Stations N9 and N10 are
shown in Table 5-8. These tests were run without
dilution and a new test was begun daily for both
stream stations.
Tables 5-9 to 5-11 give the results of the effluent
dilution tests using Station N1 water as the diluent
during the Phase II offsite testing. The Waterbury
POTW and Naugatuck POTW effluent tests diluted
with the stream water directly above each discharge
are shown on Tables 5-12 and 5-13. The results of
ambient toxicity tests on Station N9 and N10 are
given in Table 5-12. The tests were run in the
identical manner as Phase I. The only tests run during
both phases were the Station N8 dilution test and the
ambient Stations N9 and IM10.
Five of the values for the Mad River set are invalid and
are not used in Table 5-15. There are five other values
for different tests in which the control mortality
exceeded 20%. Since in none of these cases was the
effect concentration any higher than values for other
days, the values were used in Table 5-15 even though
such mortality would normally render the tests
invalid.
Table 5-15 presents the Acceptable Effluent Con-
centration (AEC) for each dilution test. The AEC is
calculated as the geometric mean of the mean no
observed effect concentration (NOEC) and the mean
of the lowest observed effect concentration (LOEC).
During Phase I Gulf Stream dilution tests had a range
of AECs from 1.7 to 54.7 percent. Torrington POTW
AECs ranged from 5.5 to > 100 percent, but three out
of seven AECs were > 100 percent. Thomaston
POTW AECs were > 100 percent for two tests, 17.3
percent in two tests, 5.5 once, and 54.7 percent once.
Steele Brook AECs were-5.5 percent for five, tests and
1.7 percent for two tests. For four tests. Great Brook
had an AEC of 1.7 percent, less than 1 percent for two
tests and 17.3 for one test. Since only two tests on
Mad River were valid, only two AECs are calculable.
They were 5.5 and 54.7 percent. The AECs for the
Station N8 dilution test were 17.3 percent for six tests
and 54.7 percent for the other.
5-1
-------
Table 5-1 . Results of Offsite Phase I Ceriodaphnia Toxicity Tests with the Gulf Stream Sample, Naugatuck River
Sample Test Mean Number 95%
or Test Concentration of Young Confidence Percent
Effluent Dates Percent (v/v) per Female Interval Survival
Gulf Stream 24Augto31Aug Dilution water
1
3
10
30
100
25 Aug to 1 Sept Dilution water
1
3
10
30
100
26 Aug to 2 Sept Dilution water
1
3
10
30
100
27 Aug to 3 Sept Dilution water
1
3
10
30
100
28 Aug to 4 Sept Dilution water
1
3
10
30
100
29 Aug to 5 Sept Dilution water
1
3
10
30
100
30 Aug to 6 Sept Dilution water
1
3
10
30
100
8.2
9.8
14.4"
13.9°
9.2
a
17.3
16.1
10.0"
4.5"
a
a
11.6
12.8
11.8
11.2
„•
a
10.3
10.9
11.6
10.6
5.5"
__a
11.4
15.1
15.6"
15.7
19.2"
a
12.4
11.3
11.2
14.7
12.7
8
16.7
15.1
14.6
19.4
16.6
a
4.5-12.1
6.8-12.8
10.8-18.1
10.4-17.4
7.2-11.2
--
13.1-21.5
13.0-19.2
8.1-11.9
0.7- 8.3
..
--
9.1-14.2
12.1-13.5
10.0-13.7
8.8-13.6
--
--
8.6-12.0
8.8-12.9
9.6-13.6
8.3-12.9
3.0- 8.0
--
8.7-14.1
12.4-17.8
13.1-18.1
12.5-19.0
17.7-20.8
--
9.8-14.9
10.3-12.3
10.0-12.3
11.5-17.8
11.2-14.2
--
1 3.0-20.4
11.3-18.9
11.5-17.7
13.6-25.2
12.5-20.7
--
100
100
100
100
75
0'
100
100
90
0"
0'
0"
70
90
80
80
0"
0°
78
70
90
89
33
0"
89
100
100
89
89
0"
60
90
90
90
100°
0*
100
90
100
100
100
0°
"Significantly different from the dilution water (P < 0.05)
The Phase II effluent dilution tests showed less
variation in the range of AECs. The Waterbury POTW
AECs were 17.3 percent for five tests and 5.5 percent
for the remaining tests. Naugatuck POTW had an AEC
of 54.7 percent for five tests and 17.3 percent for the
other two tests. The AECs for Station N8 were 17.3
percent for three tests and 54.7 percent for four tests.
Day to day variability exceeds 20 times in several
effluents indicating the need to properly sample
effluents for any type of biological or chemical
measurements. The toxic slug in the Naugatuck
POTW discussed in Chapter 4 occurred before the
tests described here were set up. The effect of dilution
water on effluent toxicity can be seen in Table 5-15
for the Naugatuck POTW. The toxicity is more than 5
times less for some samples when the effluent is
diluted with N9 water instead of N1 water. This
agrees with the lesser toxicity observed at stations 6,
7, and 8 in the ambient tests compared to the toxicity
at those stations that would be predicted from the
effluent tests.
Further discussion of the effl uent data can be found in
the paper on the mass balance model (DiToro and
Hallden, 1985).
5-2
-------
Table 5-2. Results of Offsite Phase 1 Ceriodaphnia Effluent Dilution Toxicity Tests with the Torrington POTW,
Sample Test Mean Number 95%
or Test Concentration of Young .Confidence
Effluent Dates Percent (v/v) per Female Interval
Torrington POTW 24 Aug to 31 Aug Dilution water
1
3
10
30
100
25 Aug to 1 Sept Dilution water
1
3
10
30
100
26 Aug to 2 Sept Dilution water
1
3
10
30
100
27 Aug to 3 Sept Dilution water
1
3
10
30
100
28 Aug to 4 Sept Dilution water
1
3
10
30
100
29 Aug to 5 Sept Dilution water
1
3
10
30
100
30 Aug to 6 Sept Dilution water
T
3
10
30
100
9.9
13.1
14.6
18.8"
20. 1a
12.2
15.1
15.0
14.7
11.1
18.0
a
11.5
9.7
10.7
a
a
a
12.8
11.7
13.1
8.9
6.1a
8.3
7.8
18.1
16.9
18.6,
19.5
21.9
15.1
14.3
12.8
16.7
18.7
18.9
17.0
16.5
19.2
16.6
23.2a
23.4a
7.3-12.5
9.8-16.5
11.0-18.1
14.9-22.7
15.6-24.6
7.2-17.1
9.9-20.3 .
10.5-19.5
11.0-18.3
6.6-15.6
13.7-22.3
--
9.2-13.8
8.3-11.1.
8.5-12.9
--
--
--
11.6-14.0
10.9-12.5
12.0-14.2
5.6-12.2
3.5- 8.6
1.5-15.2
0-20.0
15.0-21.2
14.1-19.7
17.0-20.1
16.3-22.7
1 9.7-24.0
11.1-19.1
11.4-17.2
9.8-15.7
1 2.9-20.5
14.5-22.9
15.3-22.5
12.9-21.1
11.5-21.5
16.2-22.2
1 2.4-20.9
21 .7-24.7
20.6-26.2
Naugatuck River.
Percent
Survival
90
80
80
90
100
90
90
90
100
80
100
Oa
100 '
50"
100
Oa
Oa
Oa
100
100
100
100
90
60a
30
70
100a
100'
100°
100a
100
100
78
100
90
100
100
88
100
89
100
100
"Significantly different from the dilution water (P < 0.05).
5-3
-------
Table 5-3. Results of Offsite Phase I Ceriodaphnia Effluent Dilution Toxicity Tests with the Thomaston POTW, Naugatuck River
Sample Test
or Test Concentration
Effluent Dates Percent (v/v)
Thomaston POTW 24 Aug to 31 Aug Dilution water
1
3
10
30
100
25 Aug to 1 Sept Dilution water
1
3
10
30
100
26 Aug to 2 Sept Dilution water
1
3
10
30
100
27 Aug to 3 Sept Dilution water
1
3
10
30
100
28 Aug to 4 Sept Dilution water
1
3
10
30
100
29 Aug to 5 Sept Dilution water
1
3
10
30
100
30 Aug to 6 Sept Dilution water
1
3
10
30
100
Mean Number
of Young
per Female
16.1
11.9
12.7
12.0
6.1°
__a
12.4
13.3
14.7
12.8
2.1 '
a
11.4
11.6
13.7
13.8
15.6
10.6
10.9
8.8
9.8
8.7
10.0
a
12.7
14.4
11.8
— "
a
a
11.9
12.7
15.7
18.5"
19.4°
8.6
14.6
13.2
7.2"
10.4
a
a
95%
Confidence
Interval
11.2-21.0
6.2-17.6
9.2-16.2
9.7-14.4
2.2-10.0
--
9.1-15.6
10.0-16.6
11.4-18.0
9.2-16.4
0.4- 3.8
--
10.3-12.5
8.2-15.0
10.2-17.2
10.0-17.5
11.9-19.4
7.1-14.0
9.2-12.5
6.5-11.1
8.9-10.8
6.0-1 1 .4
8.0-12.0
--
10.2-15.2
11.2-17.5
14.0
—
-.
--
8.0-15.9
9.8-15.6
11.8-19.6
14.3-22.7
15.9-22.9
4.0-13.2
10.2-19.1
8.8-17.8
3.23-11.1
8.0-12.8
-,
--
Percent
Survival
70
75
67
88
70
0"
70
100
90
100
80
0'
80
78
89
90
90
100
80
60
70
60
90
0"
100
80
60
0'
0°
0"
100
100
100
100
100
100
100
100
63
100
0"
0'
'Significantly different from the dilution water (P < 0.05).
.5-4
-------
Table 5-4. Results of Offsite Phase 1 Ceriodaphnia Toxicity Tests
Sample Test
°r Test Concentration
Effluent Dates Percent (v/v)
Steele Brook 24 Aug to 31 Aug Dilution water
1
3
10
30
100
25 Aug to 1 Sept Dilution water
1
3
10
30
100
26 Aug to 2 Sept Dilution Water
1
3
10
30
100
27 Aug to 3 Sept Dilution water
1
3
10
30
100
28 Aug to 4 Sept Dilution water
1
3
10
30
100
29 Aug to 5 Sept Dilution water
1
3
10
30
100
30 Aug to 6 Sept Dilution water
1
3
10
30
100
with the Steele
Mean Number
of Young
per Female
14.8
11.6
5.1
8.7
9.2
__a
11.8
9.9
8.3"
a
a
a
11.5
10.0
10.6
a
a
a
11.9
10.6
12.0
a
a
a
13.2
13.3
15.2
a
__a
_a
15.1
15.8
16.5
• a
a
a
12.0
14.5
13.7
a
a
a
Brook Sample, IMaugatuck
95%
Confidence
Interval
11:1-18.5
9.0-14.3
2.7- 7.5
2.1-15.2
7.2-11.2
9.5-14.1
7.8-11.9
6.6-10.1
X
8.3-14.7
8.2-11.7
7.9-13.4
10.1-13.7
9.4-11.8
10.5-13.4
__
10.7-15.8
11.4-15.2
12.3-18.1
__
.._ .
11.9-18.3
12.6-19.0
11.6-21.4
__
..
9.0-15.0
10.9-18.1
11.2-16.2
__
__
—
hiver
Percent
Survival
90
80
80
40a
Oa
Oa
100
70
100
Oa
oa
0"
80
70
80
Oa
na
u
Oa
80
100
80
0"
0"
na
u
80
100
100
0°
0°
oa
100
100
100
0°
oa
0"
100
100
90
10*
0"
0"
"Significantly different from the dilution water (P < 0.05).
5-5
-------
Tablo 5-5. Results of Offsite Phase 1 Ceriodaphnia Toxicity Tests with the Great Brook Sample, Naugatuck River
Sample Test Mean Number 95%
or Test Concentration of Young Confidence Percent
Effluent Dates Percent (v/v) per Female Interval Survival
Great Brook 24 Aug to 31 Aug Dilution water
1
3
10
30
100
25 Aug to 1 Sept Dilution water
1
3
10
30
100
26 Aug to 2 Sept Dilution water
1
3
10
30
100
27 Aug to 3 Sept Dilution water
1
3
10
30
100
28 Aug to 4 Sept Dilution water
1
3
10
30
100
29 Aug to 5 Sept Dilution water
1
3
10
30
100
30 Aug to 6 Sept Dilution water
1
3
10
30
100
13.4
15.2
a
a
a
a
8.5
5.2
a
a
__a
a
8.9
6.0b
__a
__a
_.°
a
10.4
12.7
a
a
a
a
13.8
7.2°
a
a
a
a
15.3
13.7
18.0
17.0
a
a
14.9
16.8
a
a
a
a
9.5-17.0
9.5-20.9
--
—
--
—
5.1-12.0
2.5- 8.0
--
--
-.
—
7.1-10.8
--
-.
—
--
--
8.6-12.2
10.9-14.5
..
--
--
--
10.8-16.8
3.7-1 0.7
—
--
--
—
11.6-19.1
11.3-16.1
14.3-21.7
12.5-21.5
—
--
12.3-17.5
12.7-20.9
--
--
—
—
75
63
0°
0"
0"
0"
90
80
0'
0°
0*
0°
30
Oa
0°
0"
0"
0"
90
100
0°
0"
0°
0"
89
67
Oa
0"
0"
0°
90
89
100
100
0"
0°
100
100
0"
0"
0°
0"
'Significantly different from the dilution water (P < 0.05).
This is a survivors only estimate. Value is mean young produced by one female.
5-6
-------
Table 5-6. Results of Offsite Phase 1 Ceriodaphnia Toxicity Tests with the Mad River Samples, Naugatuck River
Sample Test , Mean Number 95%
or Test Concentration of Young Confidence Percent
Effluent Dates Percent (v/v) per Female Interval Survival
Mad River 24 Aug to 31 Aug Dilution water
1
3
10
30
200
25 Aug to 1 Sept Dilution water
1
3
10
30
100
26 Aug to 2 Sept Dilution water
1
3
10
30
100
27 Aug to 3 Sept Dilution water
1
3
10
30
100
28 Aug to 4 Sept Dilution water
1
3
10
30
100
29 Aug to 5 Sept Dilution water
1
3
10
30
100
30 Aug to 6 Sept Dilution water
1
3
10
30
100
12.2b
10.3
16.5
4.7
—
--
12.7"
11.0
11.2
—
—
—
b
1.7
2.9
—
—
--
b
12.3
12.5
6.5
—
13.2b
16.6
13.8
—
—
—
13.3
16.5
20.7"
8
-_a
a
15.3
16.6
19.4
22.3"
10.4
a
5.3-19.2
0-25.1
12.4-20.5
0.7- 8.8
—
—
4.6-20.7
9.4-12.6
7.8-14.7
--
—
--
__
0- 3.4
0.9- 4.9
--
-.
--
_>
11.0-13.6
9.8-15.1
5.2- 7.8
--
—
3.7-22.7
13.5-19.6
10.6-16.9
--
--
—
10.5-16.1
13.2-19.7
15.2-26.2
--
--
—
11.1-19.5
12.1-21.1
15.2-23.6
19.0-25.6
0-32.3
—
40"
29
89
67
0
0
10"
90
100
0
0"
0"
Ob
10
20
0
0
0
0"
90
90
60
0
0
30b
90
70
0
0
0
100
92
100
0"
0"
0"
100
100
100
100
20"
Oa
"Significantly different from the dilution water (P < 0.05).
bDue to an error in test solution preparation these tests are invalid.
5-7
-------
Table 5-7. Results of Of fsite Phase 1 Ceriodaphnia Toxicity Tests with'Station N8
Sample Test Mean Number
or Test Concentration of Young
Effluent Dates Percent (v/v) per Female
Station N8 24Augto31Aug Dilution water
1
3
10
30
100
25 Aug to 1 Sept Dilution water
1
3
10
30
100
26 Aug to 2 Sept Dilution water
1
3
10
30
100
27 Aug to 3 Sept Dilution water
1
3
10
30
100
28 Aug to 4 Sept Dilution water
1
3
10
30
100
29 Aug to 5 Sept Dilution water
1
3
10
30
100
30 Aug to 6 Sept Dilution water
1
3
10
30
100
13.4
11.8
14.3
10.9
a
a
11.3
9.5
9.6
10.6
a
a
11.1
11.9
11.5
12.0
a
a
12.0
13.2
13.6
11.2
— •
a
12.4
10.1
17.6
13.5
a
a
17.1
19.3
22.1°
25.2"
20.2
__a
13.8
14.8
17.2
15.4
6.3'
a
Sample, Naugatuck River
95%
Confidence Percent
Interval Survival
10.9-15.9
8.7-14.9
13.0-15.6
7.4-14.4
.-
--
10.6-12.1
7.1-11.9
7.0-12.1
8.8-12.4
-.
--
5.6-16.6
10.1-13.7
9.3-13.7
6.9-17.1
—
--
9.3-14.7
11.2-15.2
12.6-14.6
9.8-12.6
--
--
9.9-14.8
7.3-13.0
13.0-22.2
8.8-18.1
--
--
13.7-20.5
15.8-22.8
18.9-25.3
19.7-30.7
17.2-23.0
--
8.9-18.7
10.5-19.1
12.6-21.7
13.1-17.6
4.6- 8.0
—
100
100
80
78
0"
0'
80
90
90
100
0"
0'
50
90
80
50
0"
0"
100
90
100
100
0°
0°
90
100
90
67
0°
0°
90
100
100
100
90
0°
90
90
89
100
60
0"
"Significantly different from the dilution water (P < 0.05).
'5-8
-------
Table 5-8.
Results of Offsite Phase I Ceriedaphnia Ambient Toxicity Tests at Stations N9 and N10, Naugatuck River
Ambient
Station
N9
N10
Test
Dates
24Aug-31 Aug
25 Aug - 1 Sept
26 Aug - 2 Sept
27 Aug - 3 Sept
25 Aug - 4 Sept
29 Aug - 5 Sept
30 Aug - 6 Sept
24 Aug -31 Aug
25 Aug - 1 Sept
26 Aug - 2 Sept
27 Aug - 3 Sept
28 Aug - 4 Sept
29 Aug - 5 Sept
30 Aug- 6 Sept
Mean Number
of Young
per Female
8.8
10.6
8.7
5.4
8.3
17.7
11.9
._
12.6
20.2
20.7
19.3
95%
Confidence
Interval
Percent
Survival
4.7-12.9
5.7-15.6
2.4-14.9
3.1- 7.6
6.6-10.0
14.2-21.1
9.5-14.2
10.2-15.0
14.6-25.8
18.0-23.5
15.0-23.6
10
0
33
40
0
10
70
90
0
0
100
100
90
100
5-9
-------
Tablo 5-9. Results of Offsite Phase II Ceriod,phnia Effluent Dilution Toxicity Tests with the Naugatuck POTW. Naugatuck River
____,„ Test Mean Number 95%
o,P Test Concentration of Young Confidence Percent
Effluent Dates Percent (v/v) per Female Interval Survival
Naugatuck POTW 31 Aug to 7 Sept Dilution water
3
10
30
100
1 Sept to 8 Sept Dilution water
3
10
30
100
2 Sept to 9 Sept Dilution water
3
10
30
100
3 Sept to 10 Sept Dilution water
3
10
30
100
4 Sept to 1 1 Sept Dilution water
3
10
30
100
5 Sept to 12 Sept Dilution water
3
10
30
100
6 Sept to 13 Sept Dilution water
3
10
30
100
12.1
11.7
12.6
14.5
12.0
a
10.7
11.9
14.5
13.2
14.1"
1.3"
10.8
11.5
12.7
12.3
9.4
3.0'
12.7
10.4
13.7
14.1
7.0"
3.6"
13.2
12.2
10.6
13.4
2.6°
a
11.6
10.5
10.4
10.8
11.9
3.0'
9.0
9.7
9.7
9.5
14.0"
2.2"
10.5-13.7
9.5-13.8
10.7-14.5
11.5-17.5
9.8-14.2
8.2-13.2
9.8-14.0
11.1-17.9
11.6-14.8
12.3-15.9
0- 2.6
8.6-13.0
10.5-12.5
11.2-14.5
10.5-14.1
6.2-12.6
0.7- 5.2
9.5-16.0
7.4-1 3.4
12.2-15.2
13.0-15.2
4.6- 9.5
2.3- 4.9
10.1-16.3
10.2-14.2 .
9.1-12.2
11.1-15.7
0.6-4.65
—
9.0-14.1
9.4-11.6
5.7-15.1
9.2-12.4
9.3-14.5
1.3- 4.7
7.0-11.1
8.0-11.4
8.2-11.2
5.5-13.5
12.3-15.7
0- 4.5
90
100
100
100
90
0°
100
100
100
90
90
50"
100
100
100
100
100
75
90
100
100
90
80
80
90
100
100
100
80
OQ
90
100
100
100
100
80
100
90
100
90
100
60"
•Significantly different from the dilution water (P < 0.05).
5-10
-------
Table 5-1 0. Results of Offsite Phase II Ceriodaphnia Effluent Dilution Toxicity Tests with the Waterbury POTW, Naugatuck River
SamPle Test Mean Number 95%
°f Test Concentration of Young Confidence Percent
Effluent Dates Percent (v/v) per Female Inteval Survival
Waterbury POTW 31 Aug to 7 Sept Dilution water
1
3
10
30
100
1 Sept to 8 Sept Dilution water •
1
3
10
30
100
2 Sept to 9 Sept Dilution water
1
3
10
30
100
3 Sept to 1 0 Sept Dilution water
1
3
10
30
100
4 Sept to 1 1 Sept Dilution water
1
3
10
30
100
5 Sept to 1 2 Sept Dilution water
1
3
10
30
100
6 Sept to 1 3 Sept • Dilution water
1
3
10
30
100
11.2
14.1
14.0
12.9
a
a
11.2
13.1
12.7
9.0
a
a
10.7
12.2
11.6
11.8
a
a
11.5
12.7
12.7
12.0
a
a
10.4
11.0
9.8
9.0
__a
a
10.1
8.9
10.6
10.7
a
a
8.0
8.4
7.8
10.7
7.4
a
8.8-13.7
12.8-15.4
13.0-15.1
11.3-14.4
--
--
8.7-13.7
12.2-14.0
11.7-13.7
7.0-11.0
..
--
8.7-12.7
10.6-13.8
10.2-12.9
9.9-13.7
--
--
8.2-14.7
11.3-14.1
11.2-14.2
10.4-13.6
-.
--
8.7-12.1
9.6-12.4
8.0-11.7
7.1-10.9
a
— B
7.2-13.0
7.5-10.3
7.3-14.0
8.0-13.4
--
--
6.4- 9.6
6.5-10.3
6.7- 9.0
9.0-12.4
5.3- 9.4
--
100
100
80
50
0"
0"
100
100
100
20°
0"
0"
100
100
90
67
Oa
0"
70
80
100
50
Oa
0"
100
100
90
30"
Oa
Oa
100
100
60
70
Oa
0°
100
100
90
80
0°
Oa
"Significantly different from the dilution water (P < 0.05).
5-11
-------
Table 5-11. Results of Offsite Phase
Naugatuck River
Sample
or Test
Effluent Dates
N8 31 Aug to 7 Sept
1 Sept to 8 Sept
2 Sept to 9 Sept
3 Sept to 1 0 Sept
4 Sept to 1 1 Sept
5 Sept to 12 Sept
6 Sept to 13 Sept
II Ceriodaphnia Ambient
Test
Concentration
Percent (v/v)
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Station Dilution
Mean Number
of Young
per Female
13.4
13.8
13.9
14.8
9.7'
a
11.9
12.0
12.3
13.8
__a
a
•10.5
10.9
10.6
11.7
11.6
6.8*
13.1
12.4
12.7
13.1
10.7
a
11.6
10.1
11.1
12.8
10.9
a
11.7
10.3
9.0
13.8
15.1
a
9.7
6.2
7,6
9.7
13.3°
a
Toxicity Tests with
95%
Confidence
Interval
12.4-14.4
13.2-14.5
11.9-15.9
13.5-16.1
6.2-13.3
--
9.9-13.9
10.9-13.1
10.5-14.1
12.5-15.1
-.
--
8.3-12.7
8.2-13.6
9.2-11.9
8.5-14.8
9.8-13.4
4.8- 8.8
11.7-14.6
10.9-13.9
11.5-13.9
12.0-14.2
7.3-14.1
--
9.3-13.8
8.6-11.7
8.9-13.3
10.8-14.8
9.3-12.5
—
10.7-12.7
7.9-12.7
6.5-11.2
10.7-16.9
11.1-19.1
--
8.0-11.4
3.4- 9.0
5.7- 9.4
7.6-11.8
11.0-15.6
—
Station N8 Samples,
Percent
Survival
J90
:90
100
100
20°
0°
80
100
100
100
0s
0°
100
86
100
67
80
0"
100
100
80
100
50'
0°
90
90
100
100
100
Oa
90
90
90
100
100
0"
100
80
90
100
100
0"
"Significantly different from the dilution water (P < 0.05).
5-72
-------
Table 5-12. Results of Offsite Phase
Naugatuck River
Sample
or Test
Effluent Dates
Waterbury POTW and 31 Aug to 7 Sept
N8 Mixture
1 Sept to 8 Sept
2 Sept to 9 Sept
3 Sept to 10 Sept
4 Sept to 1 1 Sept
5 Sept to 1 2 Sept
6 Sept to 1 3 Sept
II Ceriodaphnia Waterbury POTW and N8
Test Mean Number
Concentration of Young
Percent (v/v) per Female
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
13.5
15.9
16.7
15.1
18.5
a
10.6
11.8
14.0"
13.5b
11.7
a
11.2
12.9
11.4
12.0
12.7
a
12.1
12.3
12.5
11.1
10.6
a
11.0
10.1
11.0
11.9
12.8
a
12.8
7.5"
12.2
13.0
13.4
a
7.6
10.0
10.3
12.1a
12.5"
a
Mixture Effluent Dilution
95%
Confidence
Interval
9.8-17.2
13.3-18.5
12.2-21.1
12.4-17.8
15.4-21.6
--
9.4-11.7
10.4-13.1
13.0-15.0
12.5-14.5
10.4-13.0
--
9.4-13.1
11.4-14.4
10.0-12.8
9.5-14.5
11.6-13.8
—
10.6-13.6
11.4-13.2
11.0-14.1
9.6-12.6
9.4-11.8
--
8.0-14.0
9.2-11.0
10.0-12.0
9.1-14.8
9.7-15.8
--
10.3-15.2
4.7-10.2
10.9-13.5
10.5-15.5
12.5-14.3
—
5.8- 9.4
8.2-11.8
7.8-12.7
11.0-13.2
9.4-15.7
--
Toxicity Tests,
Percent
Survival
100
90
70
90
80
Oa
100
80
90
100
100
0"
100
100
100
100
100
0"
100
100
90
90
50
0"
100
100
100
90
70
0"
90
90
100
90
80
0"
100
100
90
100
90
0"
"Significantly different from the dilution water (P < 0.05).
5-13
-------
Table 5-13. Results of Offsite Phase II
Naugatuck River
Sample
or Test
Effluent Dates
Naugatuck POTW and 31 Aug to 7 Sept
N9 Mixture
1 Sept to 8 Sept
2 Sept to 9 Sept
3 Sept to 10 Sept
4 Sept to 1 1 Sept
5 Sept to 1 2 Sept
6 Sept to 1 3 Sept
Ceriodaphnia Naugatuck POTW and
Test Mean Number
Concentraiton of Young
Percent (v/v) per Female
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
Dilution water
1
3
10
30
100
11.5
11.5
14.6
15.7°
15.9"
14.8
11.6
10.8
15.3
16.0°
14.6°
13.7
11.3
12.7
12.0
14.2"
14.9°
10.7
10.2
11.7
12.1
14.3°
17.3°
11.8
10.6
10.3
14.1
14.5°
14.9°
8.0
5.3
12.7
12.8
14.2°
14.0°
7.2
7.9
10.7
11.7°
15.2°
16.3°
15.8°
IM9 Mixture Effluent
95%
Confidence
Interval
8.8-14.2
9.2-13.8
13.4-15.8
14.0-17.5
14.6-17.2
13.4-16.2
10.0-13.2
7.2-14.4
11.1-19.4
12.6-19.4
12.9-16.3
10.5-16.8
9.1-13.5
11.4-13.9
10.1-13.9
13.5-14.9
13.4-16.3
8.8-12.6
8.3-12.1
10.0-13.4
10.3-14.0
12.8-15.8
13.1-21.5
9.7-13.8.
8.8-12.4
8.7-12.0
11.2-17.0
11.6-17.4
12.7-17.1
5.0-11.0
0-12.1
10.2-15.2
8.3-17.3
11.4-17.0
11.3-16.7
4.8- 9.6
4.8-10.9
8.1-13.3
10.0-13.4
12.4-18.0
12.6-20.0
13.8-17.9
Dilution Toxicity Tests,
Percent
Survival
100
90
100
70
80
60
100
100
90
100
100
89
100
100
100
100
100
70
90
100
100
100
80
70
90
100
100
100
90
40
50
100°
100°
100°
100°
30
90
100
90
100
100
70
'Significantly different from the dilution water (P < 0.05).
5-14
-------
Table 5-14. Results of Off site Phase II Ceriodaphnia Ambient Station Toxicity Tests at Stations N9 and N10, Naugatuck River
Sample
or
Effluent
N9
N10 .
Test
Dates
31 Aug to 7 Sept
1 Sept to 8 Sept
2 Sept to 9 Sept
3 Sept to 1 0 Sept
4 Sept to 1 1 Sept
5 Sept to 1 2 Sept
6 Sept to 13 Sept
31 Aug to 7 Sept
1 Sept to 8 Sept
2 Sept to 9 Sept
3 Sept to 10 Sept
4 Sept to 1 1 Sept
5 Sept to 1 2 Sept
6 Sept to 1 3 Sept
Mean Number
of Young
per Female
13.5
11.9
8.1
12.4
10.0
6.1
13.4
19.8
12.8
13.0
8.7
13.3
16.3
15.4
95%
Confidence
Intervals
12.8-14.2
10.8-12.9
5.9-10.4
10.8-14.1
8.3-11.8
2.5- 9.7
11.7-15.1
17.2-22.4
11.5-14.1
12.1-13.9
5.7-11.7
11.7-14.9
13.6-19.0
14.0-16.9
Percent
Survival
20
50
50
67
20
0
50
100
100
100
20
100
70
70
Table 5-15. Summary of Offsite Ceriodaphnia Toxicity Tests Acceptable Effluent Concentrations (AEC's)
Sample or Test
Effluent Phase
Gulf Stream I
Torrington POTW I
Thomaston POTW I
Steele Brook \
Great Brook I
Mad River I
Diluent Day Testing
Water Began
N1 24 Aug
25 Aug
26 Aug
27 Aug
28 Aug
29 Aug
30 Aug
N1 24 Aug
25 Aug
26 Aug
27 Aug
28 Aug
29 Aug
30 Aug
N1 24 Aug
25 Aug
26 Aug
27 Aug
28 Aug
29 Aug
30 Aug
N1 24 Aug
25 Aug
26 Aug
27 Aug
28 Aug
29 Aug
30 Aug
N1 24 Aug
25 Aug
26 Aug
27 Aug
28 Aug
29 Aug
30 Aug
N1 24 Aug
25 Aug
26 Aug
27 Aug
28 Aug
29 Aug
30 Aug
(AEC1)
Percent Effluent
54.7
1.7
17.3
17.3
54.7
54.7
54.7
>100
54.7
5.5
17.3
__2
>100
>100
17.3
17.3
> 100
54.7
5.5
> 100
2
1.7
1.7
5.5
5.5
5.5
5.5
5.5
1.7
1.7
<1.0
1.7
<1.0
17.3
1.7
__2
2
__2
__2
2
5.5
54.7
5-75
-------
Table 5-15 (Continued)
N8 I
Waterbury POTW II
Naugatuck POTW II
N8 II
Wsterbury POTW II
Naugatuck POTW II
N1 24Aug
25Aug
26Aug
27Aug
28Aug
29Aug
30 Aug
N1 31 Aug
1 Sept
2 Sept
3 Sept
4 Sept
5 Sept
6 Sept
N1 31 Aug
1 Sept
2 Sept
3 Sept
4 Sept
5 Sept
6 Sept
N1 31 Aug
1 Sept
2 Sept
3 Sept
4 Sept
5 Sept
6 Sept
N8 31 Aug
1 Sept
2 Sept
3 Sept
4 Sept
5 Sept
6 Sept
N9 31 Aug
1 Sept
2 Sept
3 Sept
4 Sept
5 Sept
6 Sept
17.3
17.3
17.3
17.3
17.3
54.7
17.3
17.3
5.5
17.3
17.3
5.5
17.3
17.3
54.7
54.7
54.7
17.3
17.3
54.7
54.7
17.3
17.3
54.7
17.3
54.7
54.7
54.7
54.7
54.7
54.7
54.7
54.7
54.7
54.7
> 100
> 100
> 100
> 100
> 100
> 100
> 100
'AEC (Acceptable Effluent Concentration) is the geometric mean of the no observed effect concentration (NOEC) and the lowest observed
effect concentration (LOEC).
*Dash (--) Indicates test was invalid, see Tables 5-1 through 5-14.
5-16
-------
6. Hydrological Survey
Flow measurements were taken daily during the
study period to calculate and monitor the effluent
contribution to the receiving water at selected
biological stations. A dye study was performed at
three sites (Naugatuck POTW, Waterbury POTW, and
Steele Brooke) to identify the individual dilution
characteristics of each effluent. By modeling down-
stream dilution contours for each discharger, the
exposure concentration pertinent to instream effects
within the near field could then be quantified. See
Appendix C for a presentation of the hydrological
sampling methods.
6.1 Naugatuck River and Discharge
Flow Measurements
Flows measured at the biological stations during the
period 22 August to 4 September 1 983 are shown in
Table 6-1. The tidal influence of the Housatonic River
extends to Station N12 during the high water portion
of the cycle. As the river approaches high tide, the
flow at Station N12 decreases due to water being
impounded. As the water level recedes, the flow is
greater than the base flow because of the excess
storage released. The water level at Station N12 was
recorded at the start and end of each set of velocity
measurements once the tidal nature was observed.
Flow data available from four USGS stream gauging
stations within the study area are also included in
Table 6-1. These stations are located on the East and
West Branch of the Naugatuck River just above their
confluence near Torrington, at Thomaston, and at
Beacon Falls. The reported flows on the East and
West Branch were combined and treated as one
source (Table 6-1). These combined USGS flows,
which should coincide with the measured flows at
Station N2, were typically 0.14 mVsec greater.
Historical USGS data and field observation at the
confluence during this study indicates that flows on
the West Branch are typically larger than the East
Branch. In the USGS data obtained for this study
period, the flows of both branches were similar. The
fact that the combined USGS flow exceeds the
measured flow at Station N2 indicates that the East
Branch USGS flows may be overestimated. The
USGS flows at Beacon Falls were used in place of the
measured flows at Station N10 since the two stations
were within 0.4 km of each other.
The daily flow data indicate that the Naugatuck basin
is undergoing a very gradual flow decrease from 22 to
27 August (Table 6-1). This is evidenced by a decrease
from 0.59 to 0.54 mVsec at the USGS gauge at
Thomaston and a decrease from 2.24 to 1.93 mVsec
at Beacon Falls. Rain during the second half of 28
August greatly increased flows on 28 and 29 August.
Flows receded during the remaining portion of the
study and by 1 September had approached a base
level similar to the previous week.
Historical yearly average flows for the Naugatuck
River are substantially higher than the flows
observed during the study period. Historical USGS
flows average 0.69 mVsec and 1.61 mVsec for the
East and West Branch, respectively, 5.66 mVsec at
Thomaston, and 13.96 mVsec at Beacon Falls. The
USGS records indicate that monthly flows during the
late summer and the fall.are usually significantly
lower than the yearly average value. Reported 7Q10
flows for the Naugatuck River are 0.11 mVsec at the
-confluence of the East and West Branch, 0.35 mVsec
at Thomaston, and 1.71 mVsec at Beacon Falls. The
7Q10 at Beacon Falls includes approximately 0.70
mVsec from the Waterbury POTW which originates
from outside the Naugatuck basin. Examination of
Table 6-1 for 22-26 August shows that the average
USGS Thomaston flow of 0.57 mVsec was 63
percent (0.22 mVsec) higher and the USGS Beacon
Falls flow of 2.22 mVsec was 30 percent (0.51
mVsec) higher than the 7Q10 values.
During the dye studies, and from 29 August to 4
September, hourly flows were tabulated from the
plant operational strip charts of the Waterbury and
Naugatuck POTWs.The resulting daily mean, mini-
mum, and maximum discharges are presented in
Table 6-2. The Waterbury POTW had an overall mean
daily discharge of 0.78 mVsec with hourly flows
varying from 0.33 to 1.25 mVsec over the study
period. The Naugatuck POTW had an overall mean
daily discharge of 0.19 mVsec with hourly flows
varying from 0.11 to 0.32 mVsec. The Naugatuck
POTW receives both domestic and pretreated indus-
trial effluent. The industrial effluent, as reported by
the Naugatuck POTW, showed little daily variations in
flow and averaged 0.07 mVsec during this period. On
Saturday, 3 September, no industrial effluent was
discharged between 1000 and 2000 hours.
6-1
-------
Tabla 6-1. Flows Measured at Biological Sampling and USGS Stations in the Naugatuck River (mVsec)'
September
Stations
N1
N2
(USGS)6
N3
N4
N4A
(USGS)0
N5
SB1
N6
GB1
N7
MS
N8
N9
N10
(USGS)"
N11
N12
22
0,038
0.197
0.314
0.285
0.352
0.411
0.59
0.528
0.195
0.88
0.037
0.824
0.317
1.35
2.17
2.24
2.75
4.47
23
0.063
0.173
0.309
0.263
0.432
0.59
0.611
1.16
0.98
0.327
1.36
1.88
2.66
3.90
24
0.169
0.306
0.445
0.57
0.114
0.054
0.78
0.343
1.24
2.10
2.43
3.64
25
0.046
0.191
0.303
0.242
0.421
0.57
0.543
0.82
0.80
0.393
1.22
2.43
2.07
2.69
26
0.169
0.297
0.470
0.54
0.141
0.056
0.91
0.316
1.10
2.04
2.59
3.16
27
0.035
0.134
0.295
0.304
0.401
0.54
0.118
0.76
0.83
0.294
1.12
1.65
1.93
3.11
28
0.308
0.524
0.443
1.47
0.120
1.01
3.65
2.44
2.86
29
0.234
0.419
0.697
1.05
0.187
0.033
0.344
2.55
3.61
4.28
4.20
5.32
30
0.144
0.293
0.411
0.371
0.527
0.82
0.941
1.30
1.21
1.70
2.51
3.23
7.23'
31
0.257
0.396
0.621
0.76
0.135
0.059
0.398
1.58
2.10
2.52
2.77
2.51
1
0.080
0.251
0.382
0.308
0.417
0.71
0.675
1.04
1.05
1.46
1.99
2.35
2.78"
2
0.242
0.368
0.480
0.65
0.122
0.056
0.347
1.43
2.13
2.18
2.78
2.48°
3
0.052
0.208
0.357
0.407
0.62
0.96
0.82
1.23
1.67
1.95
2.01
4
0.204
0.348
0.454
0.57
0.095
0.043
0.291
1.15
1.48
1.73
2.33
2.27
"USGS data are mean daily values.
"East and West Branch gauging station information combined. Data set intended to be comparable to Station N2 measured flows.
Thomaston gauging station.
dBeacon Falls gauging station.
'Station N12 flow measurement performed at a varying water elevation.
Table 6-2. Daily Mean, Minimum, and Maximum Discharges at the Waterbury POTW and the Naugatuck POTW (m3/sec)
August September
22
23
24
25
26
29
30
31
1
Water/jury POTW
Mean
Minimum
Maximum
Naugatuck POTW
Mean 0.18'
Minimum
Maximum 0.21
0.90"
1.03
0.14"
0.11
0.21
0.78
0.44
1.04
0.54" 0.91°
0.44
1.05
0.21 " 0.19
0.14
0.32 0.23
0.81
0.43
1.25
0.19
0.13
0.22
0.77
0.35
1.10
0.19
0.13
0.23
0.74
0.39
1.01
0.19
0.13
0.23
0.69
0.34
1.01
0.14
0.11
0.17
0.65
0.33
0.99
0.16
0.11
0.26
"Calculations based on a partial day.
Source: POTW plant records.
The hourly USGS flow data at Beacon Falls exhibits a
0.42-0.57 mVsec daily variation. This variation
corresponds to the cyclic day/night flow pattern
associated with the Waterbury POTW which is
approximately 11 km upstream. On 24 and 25 August,
the dates of the dye study, the hourly flows at the
POTW and Beacon Falls are illustrated in Figure 6-1.
The excellent agreement between the two curves is
readily apparent and provides evidence of a 5-hour
lag time between the two locations. This 5-hour shift
represents a phase velocity for the propagation of a
change in discharge downstream and does not
represent a time-of-travel for a water parcel between
the two stations: the parcel velocity would be several
times slower. For 24-25 August the hourly POTW
62
flows were subtracted from the flows at Beacon Falls
taking into account the observed 5-hour shift. This
removed the cyclic pattern resulting in a uniform flow
at 1.30 mVsecfor the two days (Figure 6-1). This flow
is in reasonable agreement with the flows of 1.24 and
1.22 mVsec measured at Station N8 upstream of the
Waterbury POTW, even including a nominal flow of
0.19 mVsec for the Naugatuck POTW.
Time-of-travel studies have been performed by the
State of Connecticut several times between 1979 and
1982. The study in 1979 demonstrated that the tidal
portion of the Naugatuck River which extends ap-
proximately 3 km upstream from the confluence of
the Housatonic River and includes Station N12, has a
-------
Figure 6-1.
2.4-
2.2-
2.0-
1.8-
1.6
"o"
-------
Table 6-3. Results of Time-of-Travel Studies Performed by the State of Connecticut
June-August 1980
July-August 1981, September 1982
Station
N2-N5
N5
N5-N8
NS-N8
N8-N11
N12
River
Kilometer
63.5-41.4
41.4-38.8"
38.8-28,5
38.8-28.5
28.5- 6.6
4.7- 0.6
Travel
Time
(hr)
75.5
35.0
48.0
45.7
29.8
5.8
Average
Velocity
(m/sec)
0.082
0.021
0.061
0.064
0.201
0.195
Flow"
(M3/sec)
0.51-1.27
1.27
1.27-2.12
0.85-1.87
3.31-3.96
20.4-6.6
8.50
River
Kilometer
61.2-55.1
41.4-38.8
27.2-20.4
15.5
Travel
Time
(hr)
19.7
37.0
8.3
0.265
Average
Velocity
(m/sec)
0.085
0.018
0.195
4.81-5.24
Flow0
(mVsec)
0.59
1.13
4.25-4.59
River
Kilometer
63.5
61.2
47.5
38.8-41.5
27.2
19.4
3.0
Feature
Confluence of East and West Branch at Torrington (N2)
Torrington POTW
Thomaston POTW
Inclusive of Summit Impoundment
Waterbury POTW
Naugatuck POTW
RR Bridge at Ansonia (N12)
'Flow at beginning and end of reach.
"Summit Impoundment.
Source: DEP (1980, 1982).
12 transects described in Table C-1. The observed
background fluorescence of 0.19 ppb was subtracted
from all the instream data.
As an aid in determining the appropriate average
discharge concentration to use in the downstream
dilution ratios, the travel time for an "average" water
parcel to reach each transect was considered. Based
on each transect's cross-sectional area and a nominal
flow of 2.2 mVsec, the resulting velocites ranged
from 0.15 to 0.46 m/sec. The time for the average
parcel to reach Transect T11 (1,219 m downstream)
was 1.6 hours. Thus, while the transects were
sampled between 0930 and 1340 hours, the corre-
sponding water was leaving the discharge from 0930
to 1200 hours. This calculation, of course, does not
account for individual pools which may exchange
water at a slower rate. As a result of the above
exercise, an average discharge dye concentration of
85.5 ppb, calculated between 0900 and 1000 hours,
was used for the near-field Transects T1 to T4. At
successive downstream transects the time interval
was expanded such that, at Transects T10 and T11, a
value of 67.3 ppb was used corresponding to the
average discharge concentration from 0900 to 1200
hours. The instream samples had shown that the
average dye concentration in the downstream tran-
sects was decreasing and this use of a variable
discharge concentration was able to partially reduce
the downstream variation in the dilution ratios. The
resulting dilution contours are shown in Figure 6-2.
Only at Transect T6 and T8 was a major portion of the
transect deeper than 0.5 m, resulting in the collection
of surface and bottom samples. In these cases, the
two depths gave very similar results.
The plume from the Naugatuck POTW remained
along the right bank and did not mix past the midpoint
of the river until after passing through a narrow
constriction 365 m downstream. During this interval,
a dilution ratio of 10 was located at approximately
one-quarter of the river width. After the constriction,
the plume mixed slowly across the river with a
dilution ratio of 50 reaching the far bank of 610 m and
a dilution ratio of 20 reaching the far bank of 1,200 m
downstream. At 1,219m (Transect T11), the river was
approaching a fully-mixed condition. At this point, the
remaining horizontal dilution gradient of 15-20
corresponds to the Naugatuck POTW comprising 6.7-
5.0 percent of the Naugatuck River flow at the right
and left bank, respectivley.
6.3 Dilution Analysis of the Waterbury
POTW
The Waterbury POTW is located on the west bank of
the Naugatuck River at approximately RK 27.2. The
POTW has a maximum design flow of 1.1 m3/sec(25
mgd). During the 24-hour period of the dye study
extending from noon on 24 August to noon on 25
August, the average discharge flow was 0.79 mVsec
according to the Waterbury POTW plant records. A
6-4
-------
Figure 6-2.
Dilution contours in the Naugatuck River
downstream from the Naugatuck POTW, 23
August 1983.
15 m
Om'
100ml
200m'
minimum flow of 0.44 mVsec occurred at 0600
hours and a maximum flow of 1.04 mVsec occurred
at 1200 hours on 25 August (Table 6-2). Flows of 1.24
and 1.22 m /sec were measured on 24 and 25
August at Station N8 located 1.1 km upstream from
the POTW (Table 6-1).
Dye concentrations measured at the discharge
fluorometer on 24 and 25 August were compared to
dye concentrations calculated from the reported plant
flows and the dye injection rate of 3.08 g/min. The
measured dye concentrations averaged 0.37 ppb (3
percent) higher than the calculated concentrations.
The instream water samples were collected on 25
August from 0915 to 1350 hours at the 12 transects
described in Table C-1. The observed background was
0.12 ppb in the river and 0.42 ppb in the plant
effluent. The background fluorescence applied to the
transect data was extrapolated between these two
values in proportion to the observed dye concentra-
tion in each sample.
On the morning of 25 August, the POTW flow
increased from the observed minimum of 0.44
m /sec at 0600 hours to a flow of 0.91 mVsec at
0930 hours according to Waterbury POTW plant
records. While the instream samples were being
collected, the POTW flows were on a plateau and
varied from 0.90 to 1.04 mVsec. The varying POTW
flows and the resulting fluctuation in the discharge
dye concentration, made it necessary to estimate a
downstream travel time based upon a nominal river
flow and each transect cross-sectional area. At
Transects T1 to T6, 229 m downstream, which were
sampled between 0930 and 1105 hours, the cor-
responding "average" water particles were leaving
the discharge between 0930 and 1040 hours.
Successively longer times were required to reach the
farther downstream stations. At Transect T11 (1,433
m downstream) a 4-hour travel time was estimated
such that the water sampled at 1350 hours left the
discharge at 0950 hours. It was concluded that the
increasing plant flows and correspondingly decreas-
ing discharge dye concentrations between 0600 and
0930 hours prior to the instream samples being
collected would not have a major influence on the
observed downstream dye configuration.
A discharge dye concentration of 13.0 ppb, repre-
sentative of conditions at the time the near-field
Figure '6-2. (Continued)
15m
500m
600 mi
T11
6-5
-------
Figure 6-3. Dilution contours in the Naugatuck River
downstream from the Waterbury POTW, 25
August 1983.
Om
100m -
15 m
Flow
200m
transects were being sampled, was used to calculate
the dilution ratios. The resulting dilution contours are
shown in Figure 6-3. At Transects T6 and T7 located
in the pool above the dam and at Transect T9, a major
portion of the transect was deeper than 0.5 m,
resulting in the collection of surface and bottom
samples. Dilution differences between the two depths
were within the sampling variability. The plume from
the Waterbury POTW remained along the right bank
for the first 365 m downstream. Initially, the plume
was kept to the right bank by the flow emerging from
the left channel beyond the island in front of the
discharge and by being pushed to the outside of the
river bend that occurs at 240 m. The flow over the
dam, 420 m downstream, takes place on the opposite
side causing the river flow to transverse from right to
left as it approaches. The resulting mixing reduces
the 1.5-200 horizontal dilution gradient present 75 m
above the dam to a 1.8-2.8 dilution gradient directly
below the dam. The remaining mixing occurred more
slowly achieving a dilution gradient of 2.4-2.6 at T10
(1,067 m). The Naugatuck River was observed to be
fully mixed at T11 (1,433 m) with a dilution ratio of 2.5
which corresponds to the Waterbury POTW compris-
ing 40 percent of the total flow.
6.4 Dilution Analysis of Steele Brook
Steele Brook is a tributary which flows into the
Naugatuck River at approximately RK 33.4. During
the dye study on 26 and 27 August, flows of 0.141 •
and 0.118 mVsec were measured at Station SB1. At
the USGS gauging station near Thomaston, located
approximately 12 km upstream of the confluence
between Steele Brook and Naugatuck River, a daily
average flow of 0.54 mVsec was reported on both
days. Flow additions from the Thomaston POTW
which has a reported nominal discharge of 0.06
mVsec (1 mgd) would result in an expected flow of
0.60 mVsec for the Naugatuck River above the
confluence with Steele Brook. This value is consistent
with the flows of 0.611 mVsec and 0.543 rnVsec
measured on 23 August and 25 August at Station N5
(Table 6-1). The combined upstream and Steele Brook
flows are also consistent with the 0.76 mVsec value
measured at Station N6 on 27 August when the day
Figure 6-3. (Continued)
15m
300m
400 m'-*
6-6
-------
the instream samples were collected (Table 6-1).
Station N6 corresponds to Transect T9 for the Steele
Brook dye study.
The cross-sectionally averaged discharge dye con-
centration measured in Steele Brook at the transect
30 m above the confluence with the Naugatuck River
wa's 64.0 ppb on 26 August (1650 hours) and 74.5
ppm on 27 August (0855 hours). In order for the dye
injection rate of 2.21 g/min to result in these
observed discharge concentrations, the flow from
Steele Brook at the time of the dye measurement
would have been 12-20 percent smaller than the
flows of 0.141 and 0.118 mVsec which were
measured on the corresponding days but at different
times. An average discharge dye concentration for
the two sets of measurements of 70.0 ppb was used
to form the downstream dilution ratios.
The instream water samples were collected on 27
August from 0905 to 1215 hours at the 12 transects
described in Table C-1. The observed background
fluorescence was 0.07 ppb in Steele Brook and 0.19
ppb in the Naugatuck River above the confluence. The
background fluorescence applied to the transect data
Figure 6-3. (Continued)
15 m
500 m
600 m
700m
800m
was extrapolated between the two values in propor-
tion to the observed dye concentration in each
sample.
In the near field, depths exceeded 1 m at Transects T1
toT3 and exceeded 0.5 m at T4 such that surface and
bottom samples were collected. The dilution contours
for the near-field surface data are displayed in Figure
6-4. The dilution contours for the mid/bottom data
are presented in Figure 6-5 for the near and far field.
When only a mid-depth was sampled, the same value
was used in both figures.
The surface and bottom data at transects T1 to T4
displayed a plume which emerged from Steele Brook,
crossed the Naugatuck River on the bottom, and
surfaced 50 m downstream on the far bank (Figures
6-4 and 6-5). The Steele Brook plume then proceeded
to mix into the Naugatuck River from the far bank to
the near bank as it traveled downstream. The 5.0
dilution contour crossed the Naugatuck River below
the surface and then extended 230 m down the far
bank. On the surface, a dilution contour of 50
extended 50 m downstream from the confluence
over-riding the plume emerging from Steele Brook. At
Transect T5, which extends from 122 to 194 m
downstream, the flow passes over a wide shallow
riffle in the middle of an "S"bend. Below Transect T5
there is no longer a distinct plume and the remaining
mixing takes place slowly. At Transect T10, 1,067 m
downstream, the river has approached the fully-
mixed state at a dilution ratio of 7.2 (13.9 percent of
the river flow).
6.5 Evaluation of Dilution
Characteristics
The dye configuration studies showed that the
effluent from Steele Brook was nearly fully mixed and
from the Waterbury and Naugatuck POTWs was fully
mixed before reaching the next downstream biolog-
ical sampling station. The plume from Steele Brook
crossed the Naugatuck River on the bottom, surfaced
50 m downstream on the far bank (left), and then
mixed in from the far bank to the near bank as it
traveled downstream. At Station N6 (corresponding
to Transect T9, located 701 m downstream), the
effluent comprised 17.9 percent of the flow on the left
bank and 13.5 percent of the flow on the right bank.
The river was fully mixed by Transect T10, 1,067 m
downstream.
The plume from the Waterbury POTW remained
along the right bank of the Naugatuck River until the
flow traversed from right to left just above the dam,
located 420 m downstream. Below the dam, the
effluent comprised from 56 to 36 percent of the flow
from right to left bank, respectively. The effluent was
fully mixed at 1,430 m downstream with a 40 percent
contribution to the flow.
6-7
-------
Figure 6-4. Surface dilution contours in the Naugatuck Figure 6-5. Mid/bottom dilution contours in the Naugatuck
River downstream from Steele Brook, 27 River downstream from the Steele Brook, 27
August 1983.
August 1983.
15 m
Flow
The plume from the Naugatuck POTW remained on
the right bank of the Naugatuck River for the first 365
m and then mixed across after a narrow constriction.
The river approached a fully mixed state 1,219 m
downstream with a 5.7 percent effluent contribution.
The flow contributions of the three discharges
addressed in the dilution analysis are illustrated in
6-8
15 m
Steele Brook —
200m
400m-
T8
Figure 6-6 in relation to the total Naugatuck River
flow between Station N2 and N12. The fully mixed
(percent) flow contribution of the three discharges at
each biological sampling station is summarized in
Table 6-4. The mean flows used in Figure 6-6 and
Table 6-4 were for the period 22-26 August 1983. At
Station N12 the estimated flow of 3.0 m /sec was the
average for the period 22-26 August and 31 August
-4 September to reduce the irregular daily values due
to tidal fluctuations and sampling variability. The
flows used for the three discharges were 0.13
mVsec, 0.78 mVsec, and 0.19 mVsec for Steele
Brook, Waterbury POTW, and Naugatuck POTW,
respectively.
The flow contribution from Steele Brook decreased
from 15.7 percent at Station N6 to 4.2 percent at
Station N12 (Table 6-4). The Waterbury POTW
contribution decreased from 38.4 to 25.9 percent
from Station N9 to Station N12. Naugatuck POTW
contribution decreased from 8.6 to 6.3 percent at
Station N10 and Station N12.
The observed flows during the 22-26 August portion
-------
Figure 6-5. (Continued)
15 m
500m:
600 m|
900m
6.0
700m
<7.4
7.0
800 mf
1,OOOnrH
1,100 mi
1,200m:
Is.
7.1-7.3
T10
of the study were 0.22 mVsec and 0.51 mVsec
above a 7Q10 condition at the Thomaston and Beacon
Falls USGS gauging stations, respectively. The flow
contribution for the three discharges at Station N10,
for a 1 7.1 mVsec 7Q10 flow condition is calculated
assuming that the discharges remain at their current
discharge rates. The resulting flow contributions are
7.4, 45.4, and 11.1 percent for Steele Brook, Water-
bury POTW, and Naugatuck POTW, respectively
(Table 6-4). It is likely that under 7Q10 conditions the
discharge rates would decrease such that the above
percent contributions would be an upper limit.
6-9
-------
Figure 6-6. Flow contributions to the Naugatuck River from natural sources, POTWs, and other dischargers. Note: Rock Brook
was not included in the study design but flow contribution was calculated for this figure.
3.CK
2.5-
2,0-
^
•§- 1.5
I
1.0
0.5-
Naugatuck
POTW
Great
Brook
Thomaston
POTW*
Steele
Brook
Mad
River
Torrington
POTW'
Rock
Brook
' = Estimated Flow
M2 N3
N4
N4a N5
N6 N7 N8
N9
N10
N11
N12
Tablo 6-4. Average Naugatuck River Flow and Percent Flow Contribution from Three Discharges for the Period 22-26 August
1983
Percent Flow Contribution
Station
N2
N3
N4
N4a
N5
N6
N7
N8
N9
N10
N11
N12
Total Flow
(mVsec)
0.20
0,26
0.40
0.44
0.56
0.81
0.86
1.25
2.02
2.22
2.59
3.00
Upstream
100.0
100.0
100.0
100.0
100.0
84.3
85.2
89.8
55.3
50.7
57.8
63.6
Steele
Brook
15.7
14.8
10.2
6.3
5.7
4.9
4.2
Waterbury
POTW
38.4
35.0
30.0
25.9
Naugatuck
POTW
8.6
7.3
6.3
7O10 Condition
N10
1.71
36.1
7.4
45.4
11.1
6-JO
-------
7. Periphytic Community
The periphyton study investigated plant effects and
the recovery of the periphytic community by measur-
ing chlorophyll a and biomass and determining
periphyton abundance and composition. The relative-
ly short reproduction time and rapid seasonal fluctua-
tion in growth of periphytic algae make that com-
munity a useful indicator of localized effects resulting
from effluent toxicity. An effect on the periphytic
community may be seen in either a reduction of an
important habitat or food source for invertebrates and
fish, or in the enhancement or dominance of nuisance
species of algae that neither support other trophic
levels nor are aesthetically pleasing. The methods
used for periphyton collection and analysis are
presented in Appendix D. Supporting biological data
for periphyton are included in Appendix G.
7.1 Community Structure
Fifty-five algal taxa (51 genera) representing four
major taxonomic divisions were identified in peri-
phyton samples collected from 20 stations in the
Naugatuck River and its tributaries. Forty-eight taxa
were identified from the 13 stations in the river (Table
G-1) and 36 taxa from the 7 stations in trie tributaries
(Table G-2). Diatoms and green algae comprised most
of the taxa observed. Total periphyton
densities ranged from 1 6,264 to 115,995 units/mm
in the river and from 9,979 to 303,333 units/mm2 in
the tributaries (Tables G-1 and G-2). Diversity varied
from 1.27 to 3.85 in the river and from 1.29 to 3.38 at
tributary stations. Equitability ranges from 0.25 to
greater than 1.00 in the Naugatuck river and from
0.27 to 0.81 in the tributaries.
7.1.1 Naugatuck River
Based on the periphyton data, the portion of Nauga-
tuck River examined in this study was divided into
three sections corresponding to similarities in peri-
phyton community structure. The first section com-
prised stations N1 through N5 and was characterized
by diversities in excess of 3.0, low to moderate
densities of Stigeoclonium, and relatively diverse
diatom flora (Table G-1). The lowest total density
found in the Naugatuck River (16,264 units/mm2)
Table 7-1. Chlorophyll a and Biomass Data and Statistical Results for Periphyton Collected from Natural Substrates in the
Naugatuck River, August 1983
Parameter
Chlorophyll a
(mg/m2)
Rep 1
Rep 2
Rep 3
Mean
Biomass (g/m2)
Rep 1
Rep 2
Rep 3
Mean
Autotrophic Index
(Weber 1973)
Statistical
Results"
Chlorophyll a
F=3.292 Station"
P=0.005 Mean0
N1
134.2
32.2
38.1
68.2
15.0
12.3
35.9
21.0
309
N10
3.97
N2
117.7
84.8
133.8
112.1
15.4
12.7
19.6
15.9
142
N1
4.02
N3
195.7
151.9
268.2
205.3
28.8
44.5
15.8
29.7
145
N11
4.51
N4
123.8
208.7
150.6
161.0
20.1
48.4
63.5
44.0
273
N7
4.52
N4A
165.4
188.4
111.1
155.0
16.2
9.4
23.7
16.4
106
N5
4.70
N5
132.8
171.0
57.1
120.3
19.2
22.8
31.2
24.4
203
N2
4.71
N6
132.8
341.6
51.6
175.3
19.7
37.8
38.0
31.8
181
N9
4.80
N7
95.2
102.0
77.8
91.7
13.3
16.4
45.2
25.0
272
N6
4.90
N8
237.8
592.7
168.9
333.0
19.2
45.7
33.1
32.7
98
N4a
5.03
N9
111.1
135.5
115.8
120.8
11.0
19.3
—
15.1
125
N4
5.06
N10
42.8
51.2
64.2
52.7
6.5
9.0
11.5
9.0
171
N3
5.30
N11
53.0
1 03.0
133.7
96.6
8.0
7.9
--
7.9
82
N12
5.64
N12
254.7
586.7
149.0
330.1
31.3
61.4
57.8
50.2
152
N8
5.67
aResults based on analysis of variance and Tukey multiple comparison test procedure performed on data transformed with natural
logarithms [ln(x+1)J. Stations underscored by a continuous line were not significantly different (P >0.05).
"Stations are listed in order of increasing mean values.
cMeans of transformed data.
7-1
-------
occurred at Station N1 located west of Torrington
(Table G-1). Station N5 was located downstream from
both Thomaston Dam and Thomaston POTW, and the
highest diversity observed in the Naugatuck River
(3.85) occurred at Station N5.
The second section comprised Stations N6 through
N11 and was characterized by diversities of < 2.6,
dominated by Stigeoclonium, Scenedesmus, and/or
unidentified coccoid green algae, and usually less
diverse diatom flora dominated by Nitzschia. A three-
fold increase in total periphyton density occurred
between Station N5 and N6, the latter station being
located downstream from the confluences with
Steele Brook and Great Brook. The low diversity and
equitability at Station N6 also indicated the occur-
rence of an environmental perturbation at this station.
Evidence that conditions had improved at Station N7
was seen in diversity and equitability, both of which
were considered moderate. These parameters fluctu-
ated in this section according to station location with
respect to discharges but generally suggested de-
graded conditions of the periphyton community.
The third section was near the confluence with the
Housatonic River and included only Station N12 from
this study. This section also exhibited moderately low
diversity (2.1), but was dominated by unidentified
naviculoid green algae (possibly Oocystis) and sup-
ported large periphyton standing crops (Tables 7-1
and G-1). Maximum periphyton density in the river
(115,995 units/mm2) occurred at Station N12.
7.1.2 Tributary Stations
Maximum periphyton density observed during this
study (300,333 units/mm2) occurred at a tributary
station (SB1) located in Steele Brook (Table 7-2). The
abundance of several taxa exceeded 20,000 units/
mm2 at this station. These taxa included the diatoms
Achnanthes and Navicula, the green alga Oocystis,
unidentified coccoid forms, unidentified naviculoid
forms, and the blue-green alga Phormidium (Table
G-2). The latter forms may indeed be isolated cells of
Oocystis, a genus more commonly observed in
plankton than periphyton (Prescott 1962). The oc-
currence of Asterionella also indicated there may be
lentic habitats within the Steele Brook drainage.
Diversity and equitability were moderately high at
Station SB1 (3.05). The occurrence of potentially
planktonic taxa complicted an evaluation of water
quality at this station, but the pollution-tolerant
organism, Phormidium, was very abundant.
With the exception of Gulf Stream, the remaining
tributary stations were located within the Mad River
drainage. Total density was 70,851 units/mm2 at
Station BP1 located in the upper reaches of Beaver
Pond Brook and was reduced to 20,586 units/mm2at
Station BP2 located upstream from the confluence
with the Mad River (Table 7-2). Overall, the periphyton
results indicated good water quality for Beaver Pond
Brook (Figure 3-1).
Station M1 was located in the upper reaches of the
Mad River, and total density at this station (70,433
units/mm2) was very similar to that recorded at
Station BP1 (Table 7-2). There were, however, distinct
Tabto 7-2.
Chlorophyll a and Biomass Data and Statistical Results for Periphyton Collected from Natural Substrate* in the
Tributaries to the Naugatuck River, August 1983
Parameter
Chlorophyll a (mg/m2)
Rep 1
Rep 2
Rep 3
Mean
Biomass (g/m2)
Rep1
Rep 2
fj n
Hop 3
Mean
Autotrophic Index (Weber 1 973)
Statistical results for"
Mad River Drainage:
F = 9.531 Station"
P < O.OC2 Meanc
GS1
66.3
32.0
46.2
48.2
4.2
7.3
8.7
6.7
140
BP2
3.712
SB1
164.5
214.5
193.5
190.8
34.7
33.8
39.6
36.0
189
M2
4.047
BP1
132.6
119.5
75.9
109.3
22.9
42.7
46.4
37.4
342
BP1
4.676
BP2
31.7
48.0
41.8
40.5
26.6
13.8
30.9
23.8
587
M1
4.702
M1
99.7
94.7
137.8
110.7
34.3
25.8
55.6
38.5
348
M5
4.948
M2
50.3
53.3
66.3
56.6
19.1
12.8
18.8
16.9
298
M5
229.6
135.6
87.7
151.0
18.9
19.0
19.0
126
"!3ln«hh baSnd/°Jn1»n|!y!-S °f variance and TukeV mult|Ple comparison test procedure performed on data transformed with natural
logarithms [ln(x*1)]. Stations underscored by a continuous line were not significantly different (P > 0.05)
Stations are listed in order of increasing mean values.
'Means of transformed data.
7-2
-------
differences in species composition between these
two stations (Table G-2). Station M2 located upstream
from the confluence with Beaver Pond Brook exhib-
ited a total density of 9,979 units/mm2. As with
Beaver Pond Brook, the overall periphyton results
suggest good water quality for this portion of the Mad
River. Station M5 was located in the Mad River
downstream from the confluence with Beaver Pond
Brook and near the confluence with the Naugatuck
River. Total density at Station M5 (224,883 units/
mm2) was the second highest recorded at any
tributary station and twice as great as the highest
density observed in Naugatuck River. The periphyton
were heavily dominated by unidentified coccoid green
algae although Oocystis was also a numerically
important component of the community (Table 7-2).
Diversity and equitability were low at Station M5, and
indicated poorer water quality than at other stations
within the Mad River drainage.
7.2 Chlorophyll a and Biomass
Average chlorophyll a standing crops in the Nauga-
tuck River ranged from 52.7 to 333.0 mg/m2; biomass
standing crops varied from 7.9 to 50.2 g/m2 (Table
7-1). Statistically, the only significant difference (P <
0.05) noted in the chlorophyll a data was that standing
crops at Station N1 and N10 were less than those at
Station N8 and N12. Spatial trends in the chlorophyll
a and biomass data were similar to those described
for total periphyton densities, except for the absence
of a major peak in biomass at Station N8. Autotrophic
Index (Al) values in the river ranged from 82 to 309
(Table 7-1), and values were less than 200 at most
river stations. These values indicated that periphyton
in the Naugatuck River were typically dominated by
autotrophic(photosynthetic) rather than heterotroph-
ic (nonalgal) taxa (APHA 1981). The higher Al value
observed at Station N1 was similar to values recorded
at several tributary stations, and may have reflected
an increased importance of allochthonous material to
benthic production in these areas (Cummins 1975).
Relatively high Al values also occurred at Station N4
below the Torrington POTW and at Station N7.
Mean chlorophyll a and biomass standing crops at the
tributary stations ranged from 40.5 to 190.8 mg/m2
and from 6.7 to 38.5 g/m2, respectively (Table 7-2).
Except for a lower than expected biomass standing
crop at Station M5, spatial trends in these data were
similar to those noted for total periphyton density. The
only statistically significant difference (P < 0.05) in
chlorophyll a values within the Mad River drainage
was that standing crop at Station BP2 was less than
that at Station M5. In the tributaries, Al values varied
from 126 to 587> with values greater than approx-
imately 300 most frequent in the upper reaches, and
lower values common near the confluences of
tributaries with the Naugatuck River.
7.3 Evaluation of Periphytic Community
Response
7.3.1 Naugatuck River
Although periphyton community structure in the first
river section indicated relatively good water quality,
there was evidence of some perturbations. The first
instance of slightly reduced water quality occurred at
Station N2 where, relative to Station N1, total density
and chlorophyll a increased, while diversity, equit-
ability, and Al values decreased (Figure 7-1). Other
evidence of declining water quality was provided by
the increased relative and absolute abundances of
taxa such as Nitzschia (Palmer 1977) and
Scenedesmus (Figure 7-2). In addition, Achnanthes,
a genus more indicative of good water quality (Lowe
1974) decreased in abundance from Station N1 to
Station N2. AJthough no specific dischargers were
identified between the two stations, Station N2 was
located in the City of Torrington and downstream
from the confluence of a tributary that was not
examined in this study.
Stations N3 and N4 were potentially affected by
discharges from Gulf Stream and the Torrington
POTW. Compared to Station N2, both stations sup-
ported greater periphyton standing crops, and ex-
hibited similar or greater diversity and equitability
(Figure 7-1). Stations N3 and N4 supported less
Stigeoclonium and Phormidium but more Scenedes-
mus (Figure 7-2), as well as more typical periphytic
genera such as Achnanthes, Fragilaria, and Navicula
than Station N2. The abundance of Scenedesmus
was higher at Station N3 than at either Station N2 or
N4. These results indicate a recovery zone from the
minor pollution effects observed at Station N2. The
increased abundance of Nitzschia in this portion of
the Naugatuck River was similar to the trend observed
in the recovery zone downstream from a POTW in the
Ottawa River, Ohio (Mount et al. 1984). It appeared
that the green alga Scenedesmus also exhibited a
similar response in the Naugatuck River. Although
periphyton results indicated that Gulf Stream, which
received effluents from several known Industrial
dischargers, probably had much poorer water quality
than was generally characteristic of this portion of the
river, there was little evidence that discharges from
this tributary or from the Torrington POTW adversely
affected periphyton communities in the Naugatuck
River.
Stations N4A and N5 represented zones of down-
stream recovery from the effects noted near Tor-
rington, although Station N6 was located down-
stream from both the Thomaston Dam and Thomaston
POTW. Standing crop, diversity, and equitability at
Station N5 returned or approached values observed
at Station N1. The abundance of some genera,
especially Nitzschia, also generally declined toward
values at Station N1. It must be emphasized that this
7-3
-------
Figure 7-1. Spatial variations in periphyton standing crop, diversity, and Autotrophic Index in the Naugatuck River and selected
tributary stations (•), August 1983.
120,
Total Density
SB1» »M5
(300.3) (224.9)
Ł
s
o>
S
4a 5 6789
Stations
10 11 12
1.0n
0.8-
0.6
0.4
0.2-
Diversity
Equitability
GS1
350-i
300
250-
200-
150-
100-
50-
Autotrophic Index
GS1
1 23 4
4a 5
678
Stations
10 11 12
recovery was from minor pollution effects, compared
to the more apparent perturbations evident further
downstream, and that the upper section of the
Naugatuck River was generally characterized by
periphyton communities indicative of moderate to
good water quality.
The second section of the Naugatuck River began
with Station N6 located downstream from the con-
fluence of Steele Brook and Great Brook. Relative to
Station N5, this station exhibited greatly reduced
periphyton diversity and equitability (Figure 7-1)
resulting from dramatic increases in the relative and
absolute abundance of Stigeoclonium and unidenti-
fied coccoid green algae (Figure 7-2). Although
conditions in Great Brook were not studied because
most of its flow was underground, it is very probable
that discharges from Steele Brook, which receives
effluents from several known industrial dischargers
as well as the Waterbury POTW, were responsible for
the changes in periphyton noted at Station N6. It is
possible that the initial section of the Naugatuck River
actually extended several miles downstream from
Station N5, making the changes observed at Station
N6 more abrupt, however, additional sampling sta-
tions located between the stations would be needed
to document this hypothesis. Although the presence
of typically planktonic forms in the periphyton of
Steele Brook precluded using that data to predict
composition at Station N6, the data for Station SB1
did suggest that an increase in periphyton standing
crop was probable. An increase in standing crop was
observed at Station N6.
Periphyton at Station N7 exhibited a recovery from
the conditions observed at Station N6. Standing crop
declined whereas diversity and equitability increased
relative to values observed at Station N6 (Figure 7-1).
The absolute and relative abundance of Stigeoclon-
ium and unidentified coccoid greens decreased while
that of Nitzschia and Scenedesmus increased (Figure
7-2). These results are consistent with the conclusion
for the initial section of the river that Nitzschia and
Scenedesmus are intermediate in their tolerance
7-4
-------
Figure 7-2. Spatial variations in absolute and relative abundance of major taxonomic groups and selected periphytic taxa in the
Naugatuck River, August 1983.
30
24
18.
12-
6
Bacillariophyta
\100-,
«
•Ł= 80.
o 60
o
° 40
Ł 20-
'w
c
0)
Density
••• Percent
Chlorophyta
Cyanophyta
MOO
80
60
40
20-
1 234 4a
5 678
Stations
100 5"
80 §
60 o
40 |
20
11 12
o —
100
80
•60-I
40
20-
c
0>
Q
Stigeoclonium + Unidentified Coccoid Greens
1 23 4
4a5 678
Stations
100 S»
•80 §
60
•40
V^
•20 I-
o
D
o
o
3
•
12
and, for the Naugatuck River, are characteristic of the
moderate water quality conditions present in zones of
recovery from pollution.
Periphyton at Station N8 again exhibited the effects of
considerable environmental perturbation. Standing
crops were at the maximum for this section of the
river, diversity and equitability were lower than those
observed at Station N7 (Figure 7-1), and the com-
munity was highly dominated by Stigeoclonium and
unidentified coccoid green algae (Figure 7-2). Dis-
charge from the Mad River drainage was probably
responsible for the apparent decline in water quality
at Station N8. Several industrial discharges are
located within the Mad River drainage, and the
periphyton results for Station M5 suggest that
reduced diversity and equitability and increased
abundance of unidentified coccoid green algae should
be expected at Station N8.
With the possible exception of Station N11, little
recovery was evident for periphyton at remaining
stations in the second section of the river, which
received discharges from the Waterbury and Naug-
atuck POTWs. Although the absolute abundance of
Stigeoclonium and unidentified coccoid greens ex-
hibited progressive declines at Stations N9, N10, and
N11, these two taxonomic groups continued to
dominate periphyton communities. The abundance of
Nitzschia and Scenedesmus, which are associated
with improving water quality conditions, also declined
progressively, except for a modest increase in the
latter genus at Station N11. Diversity and equitability
remained low except for a modest improvement also
noted at Station N11. Thus, discharges from the
Waterbury and Naugatuck POTWs located upstream
of Stations N9 and N10, respectively, may have
favored the continued domination by Stigeoclonium.
Progressive changes in flow or habitat conditions or
progressive increases in dilution characteristics at
Stations N9, N10, and N11 may have been factors
affecting progressive declines in the absolute abun-
dance ofStigeoclonium.
The third section of the Naugatuck River included only
Station N12. Although this station was very similar to
Station N11 in terms of diversity and equitability,
Station N12 was sufficiently different in periphyton
standing crop and composition to be considered a
separate area of the river. Total density and biomass
standing crops at Station N12 were greater than at
any other river station, and chlorophyll a standing
crop was near the river maximum (Figure 7-1). The
periphyton community was dominated by unidentified
naviculoid green algae (possibly Oocystis), although
Nitzschia, Scenedesmus, and Stigeoclonium were
present in numbers similar to those observed at
Station N11 (Table G-1). The blue-green alga
Phormidium was much more abundant at Station
N12 than at Station N11 (6,688 units/mm2 vs. 418
units/mm2) (Table G-1). Overall periphyton results
7-5
-------
for Station N12 generally indicate poor water quality.
Because there were no known discharges to the
Naugatuck River between stations N11 and N12, and
because Station N12 was less than 2 mi from the
confluence with Housatonic River, tidal mixing of
Naugatuck and Housatonic waters was considered
the most probable explanation for sudden change in
periphyton at Station N12. However, the results of the
present study were insufficient to examine this factor.
7.4 Periphyton Community Summary
7.4.1 Naugatuck River
The Naugatuck River was divided into three sections
based on the periphyton community results. Peri-
phyton communities in the first section (Stations N1
through N5), generally were highly diverse, contained
low to moderate densities of Stigeoclonium and
unidentified coccoid green algae, and were repre-
sented by relatively diverse diatom flora. Although
these results indicated good water quality within the
section, minor pollution effects were evident at
Stations N2, N3, and N4, with N3 and N4 appearing as
zones of early recovery from effects at Station N2 in
Torrington. There was no evidence of major adverse
effects on periphyton due to discharges from Gulf
Stream (even though its water quality appeared poor)
or from the Torrington and Thomaston POTWs.
Periphyton in the second river section (Stations N6
through N11) was of low to moderate diversity,
distinctly dominated by Stigeoclonium and/or un-
identified coccoid green algae, and had diatom flora
dominated by Nitzschia. Major effects were noted at
Stations N6 and N8, downstream of discharges from
Steele Brook and the Mad River respectively, both of
which receive effluents from several industries. Some
recovery downstream of the Steele Brook discharge
was noted at Station N7, and this recovery was
characterized by reduced abundance of Stigeoclon-
ium and unidentified coccoid green algae, increased
abundance of Nitzschia and Scenedesmus, and
increased diversity and equitability. Little or no
recovery downstream of the Mad River discharge was
noted at Stations N9, N10, and N11. These results
Indicated poor to moderate water quality.
Periphyton in the third section of the Naugatuck River
(Station N12} differed from the second river section in
terms of standing crop and composition. Maximum or
near maximum standing crop occurred at Station
N12, and the community was numerically dominated
by unidentified naviculoid green algae (possibly
Oocystis). Results continued to indicate poor to
moderate water quality, but influences from the
Housatonic River, rather than direct discharges into
the Naugatuck River, were suggested as the probable
factor producing the observed results for periphyton.
7.4.2 Tributary Stations
Periphyton standing crop and diversity was similar at
Stations M1 andBPI in the upper reaches of the Mad
River drainage (Figure 7-3). The greatest difference
noted in species composition between these up-
stream stations occurred in the dominant diatoms.
Station M1 in the Mad River was dominated by
Navicula and Nitzschia, whereas Station BP1 in
Beaver Pond Brook was dominated by Achnanthes
and Gomphonema (Table G-2).
Periphyton at Stations M2 and BP2 located near but
upstream from the confluence of Beaver Pond Brook
and the Mad River were also similar. Between the
upper reaches and these stations, similar changes in
standing crop and periphyton composition were noted
in each of the tributaries (Figure 7-2). Although
known dischargers existed in this portion of Beaver
Pond Brook, none were evident in this portion of the
Mad River. These results suggest that discharges into
Beaver Pond Brook had little effect if any on peri-
phyton at Station BP2 (with.the possible exception of
elevated Al values), and water quality remained
moderate to good.
'Additional industrial dischargers were known to be
located on the Mad River between Beaver Pond Brook
and the Naugatuck River. These discharges appeared
to cause substantial increases in total periphyton
density and chlorophyll a standing crop; marked
declines in diversity, equitability, and Al values; and
domination by unidentified coccoid green algae at
Station M5. These results suggested poor water
quality at Station M5. The observed effects of this
environmental perturbation extended to Station N8 in
the Naugatuck River.
7-6
-------
Figure 7-3. Spatial variations in periphyton standing crop, diversity, Autotrophic Index, and densities of selected taxa within the
Mad River Drainage, August 1983. (BP1, BP2—Beaver Pond Brook stations; M1, M2, M5—Mad River stations).
225 Total Density
CM j.
| 80
| 60
8 40"
° 20
7 —
^
/
,
[7
c0 Diversity Navicula Achnanthes
t'J IO 1 5 |— 71
T
m \A
M1 BP1
M2
.-<
4.0-
3.0-
2.0-
1.0-
w
E 12-
171
/
/
/
/
7
/
/
/
/
.1 9-
'c
3 6-
ra §' 3.
Mi
12-
9-
6-
3-
n m
/
/
/ r~
/ hi nq |
BP2 M5 M1 BP1 M2 BP2 M5 M1 BP1 M2 BP2 M5 ' M1 BP1 M2 BP2 M
Chlorophyll a
150
120,
CJ
'-f, 90-
E 60
30-
7
/
/
/
M1 BP1
50
40-
<*Ł 30-
X
» 20
10-
Biomass
T^TI . — j
/
'
/
/
r
P_
M2
— n
1
1
R
j/
Equitability
^ '-0 15
I
j
:;i;
0.8-
0.6
0.4
0.2-
W
EE12J
p-
^
/
,
-v
/
/
^
/
,
X
W
1 9"
•I 6-
o
fx
Nitzschia Gomphonema
^-
12-
9-
6-
3-
v\ ^ n _
BP2M5 M1 BP1 M2 BP2 M5 M1 BP1 M2 BP2 M5 M1
7
/
/-
Rnn Autotrophic Index ._
DUU 1 Q o, 1 0 •
400-
300
ra 200'
100-
1
/
J
',
/
,.
_
•
>^
/
f
/
^
{
1 8-
Ł
Z3
8 4
1 S 2
F:::l
Stigeoc/onium
^O
20
15
f~*n
„ I/ : 10-
^ I/ :
x j/ •': 5-
ij 0 -'I
<;
/
/
/
/
/
/
, /
^
/
/
' M
^ H .
BP1 M2 BP2M5
Total Cyanophyta
•;•;
7
/
/
/
/
/
/
H
m I/I
M1 BP1 M2 BP2 M5
M1 BP1 M2 BP2M5
7-7
-------
-------
8. Crustacean Zooplankton Community
Planktonic communities in lotic systems are highly
unstable, and subject to local flow conditions, in
contrast to the more sedentary periphytic and benthic
communities. Crustacean zooplankton in flowing
waters almost always occur at low densities. Crus-
tacean zooplankton community effects may be evi-
dent as a change in species composition or density,
i.e., when impoundment of water behind a dam
provides habitat more suitable to the production of
limnetic zooplankton species. The methods used for
zooplankton collections and data for taxonomic
reference are included in Appendix G.
8.1 Community Composition
Eighty percent of all zooplankton species encountered
were either daphnid (7 species) or chydorid clado-
cerans (5 species) or cyclopoid copepods (4 species).
All of the species encountered are widely distributed
in North America. Both Ceriodaphnia reticulata, and
its smaller congener, C. pulchella, were encountered
in Naugatuck River samples (Tables 8-1 and G-3).
The abundance and distribution of taxa encountered
indicated that the majority of crustacean zooplankton
in the Naugatuck River were subdominant to a few
abundant taxa and were not widely distributed. The
number of taxa ranged from 1 at Station N1 to 12 at
Stations N6 and N7. Using 12 as representative of
optimum conditions and therefore considered an
"expected" value, a chi-square analysis was performed
to detect spatial difference. Results indicated that
Stations N4, N4A, N9, and N10 had significantly (P <
0.05) lower number of species than the optimum
stations. Nearly three-fourths of the crustacean
zooplankton collected were Bosmina longirostris; of
the remaining taxa, only Daphnia ambigua/parvula,
cyclopoid copepodites, nauplii, C. pulchella, and
llyocryptus spinifer constituted more than one per-
cent of the average abundance (Table 8-1).
The spatial distribution pattern of zooplankton
abundance fluctuated greatly among locations and
was exemplified by the fact that, while cyclopid
copepodites were encountered at nearly every river
station, only Bosmina longirostris, nauplii, and
llyocryptus spinifer were encountered at half, or
more, of the stations. Ceriodaphnia was the fifth most
abundant taxa collected and was encountered at 30
percent of the locations sampled (Tables 8-1 and 8-2).
Bosmina longirostris, the most abundant zooplankter,
dominated the community only at Station N5. This
station provided more than 95 percent of the total
zooplankton density collected and was probably a
product of the impoundment behind Thomaston Dam
which is located 1.5 miles upstream. Small impound-
ments upstream from Stations N11 andN12 produced
similar effects at those two stations, where zoo-
plankton densities were next highest. Species which
were most favored by the presence of these impound-
ments were the limnetic cladocerans, Bosmina
longirostris and Daphnia species; and the littoral
cladocerans, Ceriodaphnia pulchella, Diaphanosoma
brachyurum, and llyocryptus spinifer. Copepods
exhibit similar habitat affinities, but taxonomic defi-
nition was limited in the present study by the
preponderance of unidentifiable juveniles in the
population.
The species with the widest distribution in the
Naugatuck River was the littoral cladoceran, llyo-
cryptus spinifer, a taxon favored by the weedy
shallow-water habitat typical of flowing water; while
the most abundant species was the limnetic clad-
oceran, Bosmina longirostris, a taxon favored by the
open deeper-water habitat typical of the scattered
impoundments along the river. Ceriodaphnia reached
its maximum abundance at Station N5, but was also
found upstream at Stations N2 and N3 and down-
stream at Stations N6 through N8.
8.2 Evaluation of Community Response
The most evident zooplankton community responses
to perturbations in the Naugatuck River were ap-
parent by increased density and decreased diversity
at stations downstream from impoundments (Sta-
tions N5, N11, N12; Figure 8-1). Decreased diversity
at these stations resulted from increased density of a
few cladoceran species which dominated the zoo-
plankton community at those stations (Table 8-2).
Diversity at Stations N.5 and N12 were among the
lowest recorded along the river, while density was the
highest (Table 8-2). In contrast, elevated density at
Station N11 did not produce a correspondingly low
diversity because the increase in density was dis-
tributed among more taxa. Density of Ceriodaphnia
followed the overall trend for cladocerans within the
limits of its distribution.
8-1
-------
Table 8-1. Percent Abundance and Occurrence of Crustacean Zooplankton Taxa Collected from the Naugatuck River and
Tributaries, 25-27 August 1983
Taxon
Bosmlna longirostris
Daphnia ambigua/parvula"
Cyclopoid copepodite
Nauplii
Ceriodaphnia pulchella*
Hyocryptus spinifer
Diaphanosoma brachyurum
Chydorus sphaericus sphaericus
Paracyclops fimbriatus poppei
Simocephalus serrulatus
Pleuroxus denticulatus
Diaptomus pygmaeus
Calanoid copepodite
Alona rustica americana
Bucyclops agilis
Daphnia catawba
Mesocyclops edax
Scapholeberis aurita
Cyclops bicuspidatus thomasi
Leydigla leydigi
Harpacticoid copepodite
Acroperus harpae
Percent
Abundance
73.587
15.540
2.770
2.694
1.790
1.304
0.645
0.547
0.304
0.301
0.181
0.112
0.078
0.056
0.031
0.023
0.016
0.010
0.005
0.002
0.002
0.001
Percent
Occurrence
50
40
95
75
30
60
1.0
35
20
20
20
35
35
25
40
5
15
15
5
10
5
5
"Non-helmeted D. ambigua andD. parvula were not separable at 70X enumeration magnification.
"C. retlculata was also identified qualitatively at Station N5.
Tablo 8-2. Density of Crustacean Zooplankton at Sampling Stations from the Naugatuck River, 25-27 August 1983
River Stations
Taxon
Acroperus harpae
Alona rustica americana
Bosmina longirostris
Ceriodaphnia pulchella"
Chydorus sphaericus sphaericus
Daphnia ambigua/parvula"
Diaphanosoma brachyurum
Hyocryptus spinifer
Leydigia leydigi
Pleuroxus denticulatus
Scaphoteberis aurita
Simocephalus serrulatus
Total Cladocera
Nauplii
Calanoid copepodite
Cyclopoid copepodite
Diaptomus pygmaeus
Eucyclops agilis
Mesocyclops edax
Paracyclops fimbriatus poppei
Total Copepoda
Total Zooplankton
Diversity ( d }
No, of taxa
Chi square (X2)c
N1
„
—
—
—
__
—
—
—
—
—
—
2.3
—
—
2.3
2.3
0.0
1
9.19
N2 N3
2,3
23.0 36.8
6.9 -
11.5 5.3
269.4 136.8
6.9 21.1
—
324.6 36.8
„
„
644.7 236.8
5.3
..
2.3 26.3
5.3
—
„
2.3 36.8
647.0 273.7
1.50 2.22
8 7
1.02 1.69
N4
—
..
—
—
3.9
3.9
—
3.9
—
—
11.8
—
--
3.9
::
—
--
3.9
15.8
2.00
4
4.69
N4A
—
--
2.0
—
;:
~"
2.0
--
—
—
3.9
2.0
—
2.0
::
2.0
--
5.9
9.9
2.32
4
d 4.69
N5 N6
..
46.0
156,619.1 105.3
3,789.2 9.9
631.5 49.3
29,681.8 9.9
1,263.1
631.5 16.4
3.3
--
13.2
631.5 3.3
193,247.7 256.6
5,052.2 121.7
3.3
5,052.2 88.8
3.3
—
631.5 -
10,736.0 217.1
203,983.7 473.6 1
1.22 2.84
9 12
d 0.52 0
N7
—
10.5
215.8
5.3
10.5
10.5
147.4
--
--
5.3
5.3
410.5
315.8
5.3
300.0
10.5
--
5.3
636.8
,047.3
2.36
12
0
N8
-
3.9
27.6
3.9
11.8
31.5
—
—
3.9
3.9
86.8
27.6
11.8
51.3
1 1.8
15.8
--
--
118.4
205.2
3.13
11
0.02
N9
..
--
—
—
—
13.2
—
--
—
--
13.2
23.7
--
21.1
5.3
--
_-
50.0
63.2
1.83
3
6.02d
N10
-
--
—
--
—
7.9
--
—
--
--
7.9
15.8
5.3
18.4
2.6
—
--
42.1
50.0 1
2.04
4
4.69d
N11
-
--
252.6
--
536.8 2
1 15.8
21.1 1
--
--
--
—
926.2 4
115.8
10.5
110.5
21.1
10.5
5.3
--
273.7
N12
--
—
14.7
--
58.9
,762.9
,878.8
~~
22.1
--
--
,737.5
14.7
—
51.6
7.4
--
7.4
81.0
,199.9 4,818.6
2.32
9
0.52
1.25
0
1.02
aNon-halmoted D. ambigua and D. parvula were not separable at 70X enumeration magnification.
bC, rettculata was also identified qualitatively at Station N5.
cExpected value = 12 (maximum number).
"Significantly lower (p < 0.05) number of species.
8-2
-------
Figure 8-1. Spatial variation on crustacean zooplankton
diversity and density in the Naugatuck River,
August 1983. Individual data points are for the
tributary stations.
2
t POTW
,, * Thomaston Dam
GS-1
SB-1 M-5
123'4
678 9T 10 11 12
• Cladocera
0 Copepoda
Ceriodaphnia
4a'5 678 9
Sampling Station
10
11 12
Zooplankton community responses to inflowing
POTW effluent at Torrington, Waterbury, and Nauga-
tuck were largely masked by the more dramatic
effects of impoundment-associated habitat changes
(Figure 8-1). Diversity decreased downstream from
the Torrington and Waterbury POTWs, while it
increased downstream from the Naugatuck POTW
(Table 8-2). Neither decrease in diversity associated
with POTWs were as low as those associated with
impoundment effects at Stations N5 and N12. The
increase in diversity noted downstream of the Nauga-
tuck STP did not indicate recovery but was a result of a
decrease in density distributed among relatively few
taxa. Density decreased downstream from each of the
three POTWs; however, each decrease appeared to
be part of a larger decrease initiated further upstream.
Although Ceriodaphnia was not present at any of the
stations immediately downstream of the POTWs
(Stations N4, N9, and N10), it was present in
generally low abundance at other stations, so that
determination of effects upon Ceriodaphnia popula-
tions was not possible.
Likewise, tributary inflow had minimal apparent
effect on the zooplankton community. Cladoceran
densities in all three tributary systems were either
less than or very similar to adjacent stations in the
Naugatuck River (Figure 8-1). Copepod densities
were similar between Gulf Stream (Station GS1) and
the Naugatuck River Station N3. Yet copepod densi-
ties were less in Steele Brook (Station SB1) than in
the river (N5), and less in the Mad River (M5) than on
the Naugatuck River (N7) (Figures 8-1, 8-2, and 8-3).
In no case, however, was there any detectable effect
on Naugatuck River zooplankton densities from the
tributaries; rather, densities were declining in the
Naugatuck River from higher upstream densities to
lower downstream densities irrespective of tributary
inflow. Ceriodaphnia were not present at any tributary
station but were present in the river downstream of
where tributary inflow occurred. Diversity in tribu-
taries was quite similar to adjacent river stations, also
indicating no apparent effect (Table G-6). Density and
diversity of two samples collected in the Mad River
(Stations M1 and M2) and Beaver Pond Brook
(Stations BP1 and BP2) were uniformly very low,
precluding any evaluation of effects within that
tributary system (Table 8-3 and G-5). In contrast, the
number of species and zooplankton abundance was
greater at Station M5 below sources of discharge
within the Mad River compared to the upstream
stations.
In summary, the zooplankton community in the
Naugatuck River exhibited a greater response to the
presence of impoundments than to either sewage
treatment plant effluent or tributary stream inflow.
Density of a few species of crustacean zooplankton
generally increased dramatically in impounded river
reaches, resulting in lower diversity index values.
These effects masked any effects of POTW and
tributary inflows, rendering their detection impos-
sible. Both Ceriodaphnia reticulata and its smaller
congener, C. pulchella, were present in the Nauga-
tuck River, although abundances were generally low
and distribution related mostly to impoundment.
8-3
-------
Table 8-3. Density (No./m3) of Crustacean Zooplankton Taxa at Sampling Stations Along Tributaries of the Naugatuck River,
25-27 August 1983
Tributary Sampling Statiqns
Taxon
Bosmina longirostris
Daphnt'a ambigua/parvula"
Daphnia catawba
llyocryptus spinifer
Total Cladocera
Nauplii
Calanoid copopodite
Cyclopoid copcpodite
Cyclops bicuspidatus thomasi
Diaplomus pygmaeus
Eucyclops agilis
Mesocyclops edax
Paracyclops fimbr/atus poppei
Harpacticoid copepodite
Total Copepoda
Total Zooplankton
Diversity (d)
GS1
5.3
—
—
—
5.3
15.8
15.8
—
--
—
--
5.3
—
36.8
42.1
1.81
SB1
11.8
197.4
49.3
--
258.5
25.7
128.3
152.0
9.9
185.5
7.9
27.6
—
—
536.8
795.3
2.68
BP1
--
--
—
—
--
--
2.6
2.6
—
2.6
--
—
--
—
7.9
7.9
1.58
BP2
--
—
"~
—
--
3.9
3.9
""
~~
—
__
"
"
7.9
7.9
1.00
M1
--
~~
""
""
--
13.2
10.5
__
""
~"
"
""
""
23.7
23.7
0.99
M2
--
""
--
--
2.6
"
""
2.6
2.6
0.0
M5
7Q
,y
-7 n
/ .y
15.8
3.9
3.9
no
.0
Q Q
O. *7
23.7
39.5
2.45
"Non-helmeted D. ambigua and D. parvula were not separable at 70X enumeration magnification.
8-4
-------
9. Benthlc Macroinvertebrate Community
The benthic community is considered a good indicator
of ambient response to adverse conditions because of
their general lack of extensive mobility. The degree of
community stability within affected areas can be
measured by comparing composition and dominance
to that of nonaffected areas. An effect on the benthos
would be apparent as an alteration in community
structure, standing crop, or species composition of
the benthos beyond the limits of normal fluctuation
within the receiving waterbody. The increased
abundance of nuisance insect larvae or other benthic
species also would be regarded as an effect. The
following discussion is intended to present an
overview of the response of the benthic community
and selected populations to the discharges. Methods
used for benthos sampling and analysis are discussed
in Appendix D. Support benthic data on the composi-
tion, relative abundance, and community parameters
are presented in Appendix G.
9.1 Community Structure
The abundance or density of the benthos fluctuated
considerably over the study area. A taxonomic list of
organisms collected by station is presented in Table
G-4. The density ranged from approximately 1,500
organisms per m2 at Station 8 to 81,000 organisms
per m2 at Station N5 (Table 9-1; Figure 9-1). The least
dense populations were encountered from Stations
N6 through N9. The most dense populations were at
Stations N4, N4A, and N5. The number of taxa
generally declined from the upstream stations to the
downstream stations (Figure 9-1).
Composition and abundance of benthic invertebrates
varied between stations as summarized in Table 9-2
(based on the 38 most abundant taxa [Table G-5]). The
community in the study area was dominated by the
trichopterans, Cheumatopsyche, and Symphito-
psyche, which together comprised about 37 percent
of individuals. However, with few exceptions, the
benthos at most stations was dominated by midges
within the genus Cricotopus.
Community response was examined using both an
index of diversity and a community loss index
described in D-5. The community indices supported
the spatial trend of the number of species and
indicated a general decline in the health of the
benthic community associated with downstream
distance compared to the upstream communities
Figure 9-1. Spatial comparison of benthic community
parameters. Individual data points are from
tributary stations.
5-
4-
3-
2-
1.
—• Diversity
—c Community Loss Index
+ POTW
Thomaston Dam
GS1
SB1M5
h—rHs "~S. '
6 7'8 9 MO 11 12
1 00,00'
—> Total Benthos r100
'"• Number of Taxa
(D
J2
25
1 23 4
4a~5 678 91
Sampling Station
10- 11
near Torrington (Table G-6; Figure 9-1). Although no
statistical analyses were performed on the commu-
nity parameters to detect significant differences,
three general groupings of the Naugatuck River
stations can be constructed. A general decline in
community quality occurred from Station N1 to
Station N5, a decline from Station N6 to Station N8,
9-1
-------
Tabla 9-1. Average Density (No/m2) of the Most Abundant Benthic Taxa at Each Sampling Station, Naugatuck River and
Tributaries, August 1983
Station
Species
Cheumatopsyche I.
Symphitopsyche I,
Tricladida
Leucotrichia pictipes \.
Hydropsychidae I.
Cricot. bicinct. grp. I.
Nais communis
Chironomfdae p.
Cladocera
Cricot tremulus grp. I.
Cricot. cylind. grp. \.
Acarfna
Nematoda
Hydropsyche I.
Thienemannimyia ser. \.
Cardiocfadfus I.
Trichoptera I.
Baetts n.
Empididae I.
Nais bretscheri
Rheotanyhtarsus I,
Polypedilum scalaenum I.
Symphit. morosa I.
Nemorlea
Ancylidae
Trichoptera p.
Polypedilum convtctum I.
Nais variabilis
Hydroptitidae I.
Eukief. discoloripes grp.
Pristina sima
Smpididae p.
Hydropsychidae p.
Antocha I.
Orthocladius I.
Isonychia n.
Bothrio. vejdovskyanum
Nanocladius I.
Other Species
Station Total
Note.' I. = larva
p, = pupa
n. = nymph
N1
Number
Indivs
301.33
613.97
3.77
158.20
244.83
30.13
0.00
143.13
0.00
135.60
86.63
131.83
26.37
131.83
3.77
199.63
7.53
60.27
101.70
0.00
354.07
3.77
169.50
52.73
380.43
49.97
22.60
0.00
3.77
37.67
3.77
15.07
18.83
45.20
60.27
534.87
0.00
0.00
1,133.77
5,265.80
PCT
Comp
5.72
11.66
0.07
3.00
4.65
0.57
0.00
2.72
0.00
2.58
1.65
2.50
0.50
2.50
0.07
3.79
0.14
1.14
1.93
0.00
6.72
0.07
3.22
1.00
7.22
0.93
0.43
0.00
0.07
0.72
0.07
0.29
0.36
0.86
1.14
10.16
0.00
0.00
21.53
N2
Number
Indivs
199.63
1 24.30
0.00
7.53
301.33
67.80
18.83
316.40
0.00
459.53
455.77
632.80
146.90
90.40
0.00
1 54.43
0.00
0.00
1 28.07
214.70
3.77
33.90
37.67
41.43
11.30
30.13
0.00
0.00
3.77
0.00
0.00
37.67
3.77
64.03
30.13
7.53
3.7.7
7.53
1 24.30
3,759.13
PCT
Comp
5.31
3.31
0.00
0.20
8.02
1.80
0.50
8.42
0.00
12.22
12.12
16.83
3.91
2.40
0.00
4.11
0.00
0.00
3.41
5.71
0.10
0.90
1.00
1.10
0.30
0.80
0.00
0.00
0.10
0.00
0.00
1.00
0.10
1.70
0.80
0.20
0.10
0.20
3.31
N3
Number
Indivs
493.43
105.47
3.77
233.53
199.63
241.07
429.40
316.40
203.40
504.73
470.83
794.77
429.40
210.93
26.37
161.97
11.30
0.00
109.23
346.53
0.00
135.60
15.07
214.70
45.20
33.90
26.37
3.77
662.93
0.00
3.77
33.90
15.07
67.80
41.43
0.00
433.17
48.97
455.77
7,529.57
PCT
Comp
6.55
1.40
0.05
3.10
2.65
3.20
5.70
4.20
2.70
6.70
6.25
10.56
5.70
2.80
0.35
2.15
0.15
0.00
1.45
4.60
0.00
1.80
0.20
2.85
0.60
0.45
0.35
0.05
8.80
0.00
0.05
0.45
0.20
0.90
0.55
0.00
5.75
0.65
6.05
N4
Number
Indivs
621.50
184.57
o.oo.
0.00
256.13
2,998.27
7,292.27
527.33
0.00
2,049.07
549.93
305.10
259.90
1,389.90
425.63
489.67
11.30
11.30
474.60
1,243.00
0.00
519.80
11.30
41.43
384.20
86.63
387.97
768.40
0.00
0.00
139.37
3.77
15.07
3.77
45.20
0.00
97.93
184.57
1,092.33
22,871.20
PCT
Comp
2.72
0.81
0.00
0.00
1.12
13.11
31.88
2.31
0.00
'8.96
2.40
1.33
1.14
6.08
1.86
2.14
0.05
0.05
2.08
5.43
0.00
2.27
0.05
0.18
1.68
0.38
1.70
3.36
0.00
0.00
0.61
0.02
0.07
0.02
0.20
0.00
0.43
0.81
4.78
and a third decline in quality from Station N9 to
Station N12. Information illustrated by diversity and
community loss indices was generally consistent
throughout the study area with the exception of four
stations. Diversity at Stations N6, N8, and N11
declined from adjacent upstream stations due to a
substantial drop in densities (Figure 9-1). However, at
these three stations, the number of species was
similar to the adjacent stations and thus community
loss was not affected. Conversely, at Station N12,
both benthic abundance and number of species
increased from that observed at Station N11. Even-
ness was lowest at Station N12 (0.52), which
accounted for the lowered diversity value (Table G-6).
.The pattern of diversity is reflected strongly in the
evenness component of the diversity index which
considers the way individuals are distributed among
taxa. Evenness and richness, or the relative number
of taxa present, are the two primary components of
diversity, while the community loss index is influ-
enced solely by the number of taxa. The relationship
in the spatial trend of these community parameters to
the point source dischargers was fairly consistent.
The quality of the community declines following the
discharge of Gulf Stream and the Torrington POTW
and after the Thomaston Dam in the upper reach,
after the Mad River in the middle reach, and after the
Naugatuck POTW in the lower reach. An improve-
5-2
-------
Table 9-1. (Extended)
Station
Species
Cheumatopsyche I.
Symphitopsyche I.
Tricladida
Leucotrichia pictipes I.
Hydropsychidae I.
Cricot. bicinct. grp. I.
Nals communis
Chironomidae p.
Cladocera
Cricot tremu/us grp. I.
Cricot. cylind. grp. I.
Acarina
Nematoda
Hydropsyche \.
Thienemannimyia ser. I.
Cardiocladius I.
Trichoptera I.
Baetis n.
Empididae I.
/Va/s bretscheri
Rheotanyhtarsus I.
Polypedilum scalaenum I.
Symphit. morosa I.
Nemertea
Ancylidae
Trichoptera p.
Polypedilum convictum I.
/Va/'s variabilis
Hydroptilidae I.
Eukief. discoloripes grp.
Pristine sima
Empididae p.
Hydropsychidae p.
Antocha I.
Orthocladius \.
Isonychia n.
Bothrio. vejdovskyanum
Nanocladius I.
Other Species
Station Total
Note: I. = larva
p. = pupa
n. = nymph
N4A
Number
Indivs
1,020.77
3,292.07
0.00
3,035.93
327.70
67.80
7.53
109.23
0.00
64.03
150.67
135.60
177.03
3.77
15.07
1,401.20
67.80
165.73
11.30
120.53
1,318.33
15.07
30.13
26.37
322.93
11.30
60.27
0.00
0.00
376.67
0.00
11.30
45.20
339.00
169.50
0.00
0.00
0.00
764.63
13,665.47
PCT
Comp
7.47
24.09
0.00
22.22
2.40
0.50
0.06
0.80
0.00
0.47
1.10
0.99
1.30
0.03
0.11
10.25
0.50
1.21
0.08
0.88
9.65
0.11
0.22
0.19
2.37
0.08
0.44
0.00
0.00
2.76
0.00
0.08
0.33
2.48
1.24
0.00
0.00
0.00
5.60
N5
Number
Indivs
19,940.73
12,859.40
13,770.93
8,885.57
8,395.90
60.27
210.93
60.27
5,936.27
120.53
301.33
482.13
361.60
1,408.73
30.13
64.03
3,002.03
0.00
180.80
0.00
30.13
0.00
1,107.40
271.20
0.00
904.00
301.33
30.13
120.53
361.60
421.87
30.13
572.53
120.53
120.53
0.00
0.00
0.00
685.53
81,149.07
PCT
Comp
24.57
15.85
16.97
10.95
10.35
0.07
0.26
0.07
7.32
0.15
0.37
0.59
0.45
1.74
0.04
0.08
3.70
0.00
0.22
0.00
0.04
0.00
1.36
0.33
0.00
1.11
0.37
0.04
0.15
0.45
0.52
0.04
0.71
0.15
0.15
0.00
0.00
0.00
0.84
N6
Number
Indivs
56.50
15.07
18.83
11.30
45.20
139.37
0.00
90.40
3.77
71.57
116.77
372.90
320.17
33.90
56.50
1 20.53
0.00
3.77
146.90
0.00
3.77
0.00
0.00
37.67
0.00
0.00
3.77
0.00
0.00
3.77
0.00
67.80
0.00
3.77
3.77
0.00
0.00
11.30
30.13
1,789.17
PCT
Comp
3.16
0.84
1.05
0.63
2.53
7.79
0.00
5.05
0.21
4.00
6.53
20.84
17.89
1.89
3.16
6.74
0.00
0.21
8.21
0.00
0.21
0.00
0.00
2.11
0.00
0.00
0.21
0.00
0.00
0.21
0.00
3.79
0.00
0.21
0.21
0.00
0.00
0.63
1.68
N7
Number
Indivs
15.07
18.83
308.87
0.00
0.00
666.70
0.00
94.17
15.07
361.60
173.27
158.20
723.20
11.30
312.63
0.00
0.00
3.77
33.90
0.00
11.30
0.00
0.00
165.73
0.00
0.00
26.37
0.00
0.00
0.00
0.00
33.90
0.00
0.00
0.00
0.00
0.00
33.90
37.67
3,205.43
PCT
Comp
0.47
0.59
9.64
0.00
0.00
20.80
0.00
2.94
0.47
11.28
5.41
4.94
22.56
0.35
9.75
0.00
0.00
0.12
1.06
0.00
0.35
0.00
0.00
5.17
0.00
0.00
0.82
0.00
0.00
0.00
0.00
1.06
0.00
0.00
0.00
0.00
0.00
1.06
1.18
ment in the benthic community was obsered follow-
ing the Waterbury POTW in the middle reach.
Although these findings are not conclusive, they
indicate the presence of both gross effects from
individual dischargers and a degradation of the
benthic community from upstream to downstream.
In comparison to the Naugatuck River stations, both
the diversity and community loss indices for the
tributaries indicated that tributaries had degraded
communities compared to adjacent, river stations
(Table G-6; Figure 9-1). Densities and number of taxa
were reduced in the tributaries from that observed at
the Naugatuck River stations.
9.2 Differences Between Stations
An understanding of the abundance and distribution
of major taxonomic groups of benthic organisms is
important in interpreting the interaction among
various components of the community and hence the
spatial trends in dominance .and composition. With
one exception (Station N6) the trichopterans (cad-
disflies) and chironomids (midge larvae) constituted
more than 50 percent of the benthos in the upper
reach of the Naugatuck River (Table 9-2). However,
the chironomids composed more than 60 percent of
the benthos in the lower reach (Stations N9 through
N12). The oligochaetes were abundant only at
9-3
-------
Table 9-1. (Extended)
Station
Species
Cheumatopsyche \.
Symphitopsyche I.
Tricladida
Leucotrlchia pictipes I,
Hydropsychidae I.
Cricot. bicinct. grp. L.
Nats communis
Chironomidae p.
Cladocera
Cricot tremulus grp. \.
Cricot. cylind. grp. \.
Acarina
Nematoda
Hydropsyche I.
Thienemannimyia ser. I.
Cardiocladius I.
Trichoptera I.
Baetis n.
Empididae I.
Nais bretscheri
Rheotanyhtarsus I.
Polypedilum scalaenum I.
Symphil, morosa I.
Nemertea
Ancylidae
Trichoptera p.
Polypedilum convictum I.
AAs/s varfabilts
Hydroptilidae I.
Eukief. discoloripes grp.
Pristina sima
Empididae p.
Hydropsychidae p.
Antocha I.
Orthocladius I,
Isonychia n.
Bothrio. vejdovskyanum
Nanocladius I.
Other Species
Station Total
Note: I. = larva
p. = pupa
n. = nymph
N8
Number
Indivs
3.77
22.60
64.03
0.00
0.00
161.97
0.00
82.87
0.00
15.07
30.13
71.57
757.10
3.77
26.37
33.90
0.00
7.53
1 73.27
0.00
3.77
0.00
3.77
0.00
0.00
0.00
3.77 .
0.00
0.00
0.00
0.00
3.77
0.00
0.00
3.77
3.77
0.00
18.83
7.53
1,502.90
PCT
Comp
0.25
1.50
4.26
0.00
0.00
10.78
0.00
5.51
0.00
1.00
2.01
4.76
50.38
0.25
1.75
2.26
0.00
0.50
11.53
0.00
0.25
0.00
0.25
0.00
0.00
0.00
0.25
0.00
0.00
0.00
0.00
0.25
0.00
0.00
0.25
0.25
0.00
1.25
0.50
N9
Number
Indivs
11.30
7.53
0.00
0.00
3.77
214.70
0.00
519.80
0.00
534.87
376.67
33.90
105.47
0.00
75.33
22.60
0.00
105.47
203.40
0.00
7.53
135.60
0.00
0.00
3.77
0.00
33.90
3.77
0.00
0.00
0.00
64.03
0.00
0.00
0.00
0.00
0.00
15.07
173.27
2,651.73
PCT
Comp
0.43
0.28
0.00
0.00
0.14
8.10
0.00
19.60
0.00
20.17
14.20
1.28
3.98
0.00
2.84
0.85
0.00
3.98
7.67
0.00
0.28
5.11
0.00
0.00
0.14
0.00
1.28
0.14
0.00
0.00
0.00
2.41
0.00
0.00
0.00
0.00
0.00
0.57
6.53
N10
Number
Indivs
15.07
7.53
0.00
7.53
0.00
406.80
0.00
1,310.80
3.77
587.60
1 1 3.00
18.83
109.23
0.00
214.70
365.37
0.00
1,404.97
372.90
0.00
0.00
1 80.80
3.77
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1 92.1 0
0.00
0.00
0.00
0.00
0.00
15.07
101.70
5,431.53
, PCT
Comp
0.28
0.14
0.00
0.14
0.00
7.49
0.00
24.13
0.07
10.82
2.08
0.35
2.01
0.00
3.95
6.73
0.00
25.87
6.87
0.00
0.00
3.33
0.07
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
3.54
0.00
0.00
0.00
0.00
0.00
0.28
1.87
N1
Number
Indivs
3.77
0.00
0.00
0.00
3.77
497.20
15.07
248.60
0.00
116.77
135.60
11.30
37.67
0.00
670.47
67.80
0.00
455.77
165.73
0.00
0.00
109.23
0.00
0.00
0.00
0.00
67.80
0.00
0.00
0.00
0.00
82.87
0.00
0.00
0.00
0.00
0.00
0.00
116.77
2,806.17
1
PCT
Comp
0.13
0.00
0.00
0.00
0.13
17.72
0.54
8.86
0.00
4.16
4.83
0.40
1.34
0.00
23.89
2.42
0.00
16.24
5.91
0.00
0.00
3.89
0.00
0.00
0.00
0.00
2.42
0.00
0.00
0.00
0.00
2.95
0.00
0.00
0.00
0.00
0.00
0.00
4.16
Stations N3 and N4. With the exception of the
miscellaneous grouping which including various
minor phyla such as nematodes and water mites, the
other major groups did not constitute more than 12
percent of the benthos at the Naugatuck River
stations. The chironomids and oligochaetes generally
dominated the tributary stations (Table 9-2)..Only at
Station M2 were the caddisflies the predominant
group. The miscellaneous species group was numer-
ically important at most tributary stations except in
the upper Mad River tributary.
Certain key taxa represent the greatest contribution
to total abundance of the benthic community eval-
uated under diversity and its components. The
9-4
predominant trichopterans encountered in the Naug-
atuck River were species of Cheumatopsyche and
Symphitopsyche (Table 9-1). The spatial trends of the
abundance of these genera were similar and illus-
trated that of the total group (Figure 9-2). The peak
densities of these genera occurred at Station N5 and
composed the majority of the benthos at that station,
hence increasing the redundancy value and decreas-
ing diversity. For Cheumotopsyche, the abundance (P
= 0.0001) was significantly greater than that at other
stations (Table G-9). Although the density of
Symphitopsyche was significantly (P = 0.0001) dif-
ferent among stations, the results of a Tukey's
multiple-range test indicated the densities at Stations
-------
Table 9-1. (Extended)
Station
Species
Cheumatopsyche I.
Symphitopsyche I.
Tricladida
Leucotrichia pictipes I.
Hydropsychidae I.
Cricot. bicinct. grp. I.
Nais communis
Chironomidae p.
Cladocera
Cricot tremulus grp. I.
Cricot. cylind. grp. I.
Acarina
Nematoda
Hydropsyche I.
Thienemannimyia ser. I.
Cardiocladius I.
Trichoptera I.
Baetis n.
Empididae I.
/Va/s bretscheri
Rheotanyhtarsus \.
Polypedilum scalaenum I.
Symphit. morosa \.
Nemertea
Ancylidae
Trichoptera p.
Polypedilum convictum I.
/Va/s variabilis
Hydroptilidae I.
Eukief. discoloripes grp.
Pristina sima
Empididae p.
Hydropsychidae p.
Antocha I.
Orthocladius I.
Isonychia n.
Bothrio. vejdovskyanum
Nanocladius \.
Other Species
Station Total
Note: I. = larva
p. = pupa
n. = nymph
N12
Number
Indivs
3.77
3.77
7.53
0.00
7.53
2,772.27
0.00
2,015.17
22.60
116.77
730.73
226.00
37.67
0.00
523.57
0.00
0.00
22.60
11.30
0.00
0.00
0.00
0.00
0.00
0.00
0.00
45.20
0.00
3.77
0.00
0.00
7.53
0.00
0.00
0.00
0.00
0.00
82.87
226.00
6,866.63 '
PCT
Comp
0.05
0.05
0.11
0.00
0.11
40.37
0.00
29.35
0.33
1.70
10.64
3.29
0.55
0.00
7.62
0.00
0.00
0.33
0.16
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.66
0.00
0.05
0.00
0.00
0.11
0.00
0.00
0.00
0.00
0.00
1.21
3.29
GS1
Number
Indivs
0.00
0.00
0.00
0.00
0.00
0.00
3.77
37.67
0.00
82.87
37.67
365.37
48.97
0.00
18.83
11.30
0.00
0.00
71.57
0.00
0.00
30.13
0.00
0.00
0.00
0.00
64.03
0.00
0.00
0.00
0.00
105.47
0.00
0.00
3.77
0.00
3.77
0.00
86.63
971.80
PCT
Comp
0.00
0.00
0.00
0.00
0.00
0.00
0.39
3.88
0.00
8.53
3.88
37.60
5.04
0.00
1.94
1.16
0.00
0.00
7.36
0.00
0.00
3.10
0.00
0.00
0.00
0.00
6.59
0.00
0.00
0.00
0.00
10.85
0.00
0.00
0.39
0.00
0.39
0.00
8.91
M1
Number
Indivs
26.37
7.53
0.00
0.00
26.37
48.97
173.27
226.00
0.00
22.60
418.10
361.60
237.30
75.33
3.77
0.00
3.77
0.00
18.83
0.00
0.00
0.00
0.00
263.67
0.00
7.53
0.00
7.53
26.37
0.00
150.67
3.77
0.00
0.00
7.53
0.00
0.00
33.90
207.17
2,357.93
PCT
Comp
1.12
0.32
0.00
0.00
1.12
2.08
7.35
9.58
0.00
0.96
17.73
15.34
10.06
3.19
0.16
0.00
0.16
0.00
0.80
0.00
0.00
0.00
0.00
11.18
0.00
0.32
0.00
0.32
1.12
0.00
6.39
0.16
0.00
0.00
0.32
0.00
0.00
1.44
8.79
M2
Number
Indivs
64.03
33.90
0.00
0.00
41.43
11.30
0.00
15.07
0.00
7.53
22.60
7.53
7.53
259.90
7.53
3.77
3.77
3.77
7.53
7.53
0.00
0.00
0.00
22.60
0.00
3.77
0.00
0.00
0.00
0.00
3.77
0.00
0.00
7.53
18.83
0.00
0.00
0.00
11.30
572.53
PCT
Comp
11.18
5.92
0.00
0.00
7.24
1.97
0.00
2.63
0.00
1.32
3.95
1.32
1.32
45.39
1.32
0.66
0.66
0.66
1.32
1.32
0.00
0.00
0.00
3.95
0.00
0.66
0.00
0.00
0.00
0.00
0.66
0.00
0.00
1.32
3.29
0.00
0.00
0.00
1.97
N5, N4A, and N1 to be similar. Significant station
differences (P = 0.0001) were obtained from ANOVA
on total Trichoptera, but considerable overlap existed
among stations (Table G-8). Some fluctuation in
abundance among the two genera and early instars
occurred at the upstream stations and may have had
some influence on the fluctuations in diversity at
these stations.
The ephemeropterans (mayflies) were not a numer-
ically dominant benthic group, but did attain three
major abundance peaks (Figure 9-2). In the upper
reach where peaks in abundance occurred at Stations
N1 and N4A, the genus Isonychia was responsible for
major densities of mayflies at Station N1 and Baetis
sp. at Station N4A (Table 9-1). The mayflies were not
abundant in the middle reach of the Naugatuck River,
but peaked at Station N10 in the lower reach which
was due to a high density of Baetis sp. No direct
effects from individual dischargers upon either the
mayflies or caddisf lies were readily apparent. Rather,
effects were more generalized and appeared to be
associated with degradation of reaches of the river.
The Chironomidae were relatively abundant' at all
Naugatuck River stations, fluctuating between a low
density of 400/m2 at station 8 to a peak density of
6,500/m2 at Station N12 (Figure 9-3). The chiron-
omids were generally less abundant in the middle
reach. Although results of Tukey's multiple-range
9-5 '
-------
Table 9-1. (Extended)
Station
Species
Cheumatopsyche I.
Symphitopsyche I.
Trlcladida
Leucotrichia pictipes I.
Hydropsychidae I.
Cricot. bicinct, grp. I.
Nais communis
Chironomidae p.
Cladocora
Crfcot tremufus grp. I.
Cricot. cylfnd. grp. I,
Acarina
Nematoda
Hydropsyche I,
Thienemannimyia ser. I.
Cardiocladius I.
Trichoptera \,
Baetis n.
Empididae I.
/Va/s bretscheri
Rheotanyhtarsus I.
Polypedilum scalaenum I.
Sympfiit, morosa I.
Nemertea
Ancylidae
Trichoptera p
Polypedilum convictum I.
/Va/s variabilis
Hydroptilidae I.
Eukief. discoloripes grp.
• Pristine sima
Empididae p.
Hydropsychidae p.
Antocha I.
Orthocladius I.
Isonychia n.
Bothrio, vejdovskyanum
Nanocladius I.
Other Species
Station Total
Note: I. = larva
p. = pupa
n. = nymph
M5
Number
Indivs
0.00
0.00
3.77
0.00
3.77
22.60
0.00
3.77
0.00
0.00
0.00
7.53
48.97
0.00
22.60
26.37
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
15.07
1 54.43
PCT
Comp
0.00
0.00
2.44
0.00
2.44
14.63
0.00
2.44
0.00
0.00
0.00
4.88
31.71
0.00
14.63
17.07
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
9.76
BP1
Number
Indivs
11.30
0.00
0.00
3.77
11.30
11.30
41.43
37.67
0.00
7.53
101.70
214.70
60.27
0.00
478.37
11.30
0.00
82.87
18.83
0.00
0.00
203.40
3.77
0.00
0.00
0.00
11.30
18.83
0.00
3.77
3.77
11.30
0.00
3.77
3.77
0.00
0.00
7.53
644.10
2,007.63
PCT
Comp
0.56
0.00
0.00
. 0.19
0.56
0.56
2.06
1.88
0.00
0.38
5.07
10.69
3.00
0.00
23.83
0.56
0.00
4.13
0.94
0.00
0.00
10.13
0.19
0.00
0.00
0.00
0.56
0.94
0.00
0.19
0.19
0.56
0.00
0.19
0.19
0.00
0.00
0.38
32.08
BP2
Number
Indivs
0.00
56.50
0.00
0.00
82.87
97.93
248.60
331.47
0.00
297.57
527.33
331.47
263.67
101.70
474.60
0.00
3.77
516.03
177.03
0.00
0.00
252.37
11.30
15.07
0.00
0.00
67.80
26.37
0.00
0.00
45.20
60.27
0.00
3.77
105.47
0.00
0.00
0.00
346.53
4,444.67
PCT
Comp
0.00
1.27
0.00
0.00
1.86
2.20
5.59
7.46
0.00
6.69
11.86
7.46
5.93
2.29
10.68
0.00
0.08
11.61
3.98
0.00
• o.oo
5.68
0.25
0.34
0.00
0.00
1.53
0.59
0.00
0.00
1.02
1.36
0.00
0.08
2.37
0.00
0.00
0.00
7.80
SB1
Number
Indivs
0.00
0.00
0.00
0.00
0.00
18.83
3.77
7.53
o.eo
0.00
0.00
18.83
48.97
0.00
52.73
0.00
0.00
0.00
18.83
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
3.77
30.13
203.40
PCT
Comp
0.00
0.01
0.00
0.00
0.00
9,26
1.85
3.70
0.00
0.00
0.00
9.26
24.07
0.00
25.93
0.00
0.00
0.00
9.26
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
1.85
14.81
Total
Number
1,139.42
867.65
709.08
617.17
497.58
426.76
422.24
324.69
309.24
277.79
239.94
234.10
210.37
186.07
171.95
156.69
155.56
142.19
121.29
96.61
86.63
80.98
69.68
57.63
57.44
56.31
56.12
42.94
41.06
39.17
38.61
38.23
33.52
32.96
30.70
27.31
26.93
23.17
314.52
8,460.36
Comp
PCT
13.47
10.26
8.38
7.29
5.88
5.04
4.99
3.84
3.66
3.28
2.84
2.77
2.49
2.20
2.03
1.85
1.84
1.68
1.43
1.14
1.02
0.96
0.82
0.68
0.68
0.67
0.66
0.51
0.49
0.46
0.46
0.45
0.40
0.39
0.36
0.32
0.32
0.27
3.72
test applied to the log transformed counts a posterior
exhibited considerable overlap among stations. No
consistent spatial trend in densities of the three
principal species of Cricotopus could be discerned
along the river gradient (Figure 9-3). However, station
differences were significant (P < 0.01) for all three
species (Table G-10). The densities of the three
species were generally within an order of magnitude
of each other and fluctuated in dominance between
stations.
The oligochaetes fluctuated from less than 100
individuals/m2at several stations to a peak density of
over 10,000/mz at Station N4. The oligochaete, Nais
communis, peaked in abundance at Station N4
accounting for almost 72 percent of the oligochaetes
at that station. Generally, N. communis had a highly
variable spatial distribution increasing in abundance
downstream of the Torrington, Thomaston, and
Waterbury POTWs (Table 9-1). However, other spec-
ies of oligochaetes such as Nais bretscheri, Pristine
sima, and Bothrioneurum vejdovskyanum were pre-
dominant at stations other than at Station N4.
9.3 Station Comparisons of the Number
of Benthic Taxa
Naugatuck River flows increased from 0.2 mVsec in
the headwaters of the study area to 3 mVsec at the
farthest downriver station (N12). Differences in
benthic community structure among the stations may
3-6
-------
Table 9-2.
Density (No./m2) and Percent Composition of Major Benthic Taxa Collected from the Naugatuck River and
Tributaries, August 1983
Station N1
Station N2
Station N3
Station N4
Station N5
Species
Trichoptera
Chironomidae
Ephemeroptera
Oligochaeta
Mollusca
Other Diptera
Other Insects
Miscellaneous
Total
Table 9-2. (Extended)
Species
Trichoptera
Chironomidae
Ephemeroptera
Oligochaeta
Mollusca
Other Diptera
Other Insects
Miscellaneous
Total
Number
Indivs
1,853.20
1,367.30
1,069.73
22.60
429.40
161.97
143.14
218.47
5,265.81
Station
Number
Indivs
57,637.53
1,604.60
30.13
693.07
0
331.47
0
20,852.26
81,149.06
PCT
Comp
35.19
25.97
20.31
0.43
8.15
3.08
2.72
4.15
N5
PCT
Comp
71.03
1.98
0.04
0.85
0
0.41
0
25.70
Number
Indivs
813.60
1,589.53
11.30
241 .07
33.90
233.54
15.07
821.13
3,759.14
Station
Number
Indivs
161.97
621.50
3.77
11.30
0
229.76
7.54
753.34
1.789.18
PCT
Comp
21.64
42.28
0.30
6.41
0.90
6.21
0.40
21.84
N6
PCT
Comp
9.05
34.74
0.21
0.63
0
12.84
0.42
42.10
Number
Indivs
2,000.10
2,188.43
18.83
1,333.40
45.20
222.23
52.73
1 ,668.B3
7,529.55
Station
Number
Indivs
45.20 •
1,710.07
3.77
0
0
75.33
0
1,371.07
3,205.44
PCT
Comp
26.56
2906
0.25
17.71
0.60
2.95
0.70
22.16
N7
PCT
Comp
1.41
53.35
0.12
0
0
2.36
0
42.78
Number
Indivs
2,576.40
8,463.70
11.30
10,147.40
436.93
512.26
30.13
693.07
22,871.19
Station
Number
Indivs
33.90
384.20
11.30
0
0
1 77.03
3.77
892.70
1,502.90
PCT
Comp
11.26
37.01
0.05
44.37
1.91
2.24
0.13
3.03
N8
PCT
Comp
2.26
25.56
0.75
0
0
11.78
0.25
59.40
Number
Indivs
7,902.47
4,015.27
516.03
169.50
327.70
391.74
3.77
339.00
13,665.48
Station
Number
Indivs
26.37
2,01 8.93
1 05.47
79.10
3.77
274.96
3.77
139.37
2,651.74
PCT
Comp
57.83
29.38
3.78
1.24
2.40
2.87
0.03
2.48
N9
PCT
Comp
0.99
76.14
3.98
2.98
0.14
10.37
0.14
5.26
Table 9-2. (Extended)
Station N10
Station N11
Station N12
Station GS1
Station M1
Species
Trichoptera
Chironomidae
Ephemeroptera
Oligochaeta
Mollusca
Other Diptera
Other Insects
Miscellaneous
Total
Number
Indivs
33.90
3,261.93
1,412.50
0
0
572.53
18.83
131.83
5,431.52
PCT
Comp
0.62
60.06
26.01
0
0
10.54
0.35
2.43
Number
Indivs
7.53
1,973.73
455.77
30.13
0
256.13
33.90
48.97
2,806.16
PCT
Comp
0.27
70.34
16.24
1.07
0
9.13
1.20
1.74
Number
Indivs
18.83
6,478.67
22.60
3.77
0
18.83
30.14
293.80
6,866.64
PCT
Comp
0.27
94.35
0.33
0.05
0
0.27
0.43
4.28
Number
Indivs
0
308.87
0
7.53
0
207.1 7
33.90
414.34
971.81
PCT
Comp
0
31.78
0
0.78
0
21.32
3.49
42.64
Number
Indivs
1 84.57
764.63
30.13
369.13
0
22.60
11.30
975.57
2,357.93
PCT
Comp
7.83
32.43
1.28
15.65
0
0.96
0.48
41.38
Table 9-2. (Extended)
Station M2
Station M5
Station BP1
Station BP2
Station SP1
Species
Trichoptera
Chironomidae
Ephemeroptera
Oligochaeta
Mollusca
Other Diptera
Other Insects
Miscellaneous
Total
Number
Indivs
406.80
86.63
11.30
11.30
0
15.07
0
41.43
572.53
PCT
Comp
71.05
15.13
1.97
1.97
0
2.63
0
7.24
Number
Indivs
3.77
75.33
0.00
3.77
0
0
11.30
60.26
1 54.43
PCT
Comp
2.44
48.78
0.00
2.44
0
0
7.32
39.03
Number
Indivs
33.90
1,065.97
86.63
455.77
11.30
52.74
15.07
286.27
2,007.65
PCT
Comp
1.69
53.10
4.32
22.70
0.56
2.63
0.75
14.26
Number
Indivs
256.13
2,282.60
523.57
463.30
26.37
248.60
15.07
629.04
4,444.68
PCT
Comp
5.76
51.36
11.78
10.42
0.59
5.59
0.33
14.15
Number
Indivs
0
97.93
0
• 7.53
0
26.36
3.77
67.80
203.39
PCT
Comp
0
48.15
0
3.70
0
12.96
1.85
33.33
9-7
-------
Figure 9-2.
10,000 3,
Spatial trend in abundance of Trichoptera and
Ephemeroptera and predominant trichopteran
genera in Naugatuck River.
57,000
Trichoptera
Ephemeroptera
t POTW
Thomaston Dam
1*-^
1 23 4
100,000i
4a 5
6781" 9T10 11 12
Cheumatopsyche Larvae
Syrnphitopsyche Larvae
Hydropsychidae Early jnstar
t POTW
Thomaston Dam
10
4a' 5 67!
Sampling Station
11 12
Figure 9-3.
10,000
2,000-
Spatial trends in abundance of Chironomidae
and Oligochaeta and predominant chironomid
species groups in the Naugatuck River.
1,000-
cS"1
E
o>
a
200
100
20
10
1
10,000
2,000.
1,000-
200
o
— 100
E
M
20
10
. Chironomidae
• Oligochaeta
POTW
Thomaston Dam
i
l '
l /
i /
i (
,'.
i \
i i
/ i
/ i
i \
i \
i \
1 23 4
4aT5
—i t-Tj. r-r—• 1 1
678 9* 10 11 12
..*
; Cricotopus bicinctus Group Larvae
— Cricotopus tremulus^ Group Larvae
••'• • Cricotopus cyiinclraceus"Group Larvae
* POTW
+ Thomaston Dam
1 23*4 43*5678^9*10
Sampling Station
11 12
be highly influenced by the differences in the flow
regime along the river gradient. To test this relation-
ship, a nonlinear regression was performed on the
number of benthic taxa versus river flow (M3/sec).
The results indicated that variation in the number of
taxa in the upper reach of the Naugatuck River
(Stations N2 through N7) is related to flow differences
as represented by the steep slope on Figure 9-4.
However, the number of benthic taxa in the lower
reach of the Naugatuck River (Stations N8 through
N12) is not influenced to any great extent by flow
(—horizontal slope).
9-8
-------
Figure 9-4. Nonlinear regression of the number of benthic taxa on flow.
65
60
55-
. 50
X
03
!H 45.
j;
c
CD 40
d
z
35-
30-
25-
20-
.P.
D
D
-P
0.0 0.2
0.4
06
08 U>
12
US
U3
2LO
2A
Flow
2JS
3X)
A plot of the residuals (actual minus predicted number
of taxa) versus flows and associated standard devia-
tions indicates that the greatest deviation from the
predicted value occurs in the upper reach of the
Naugatuck River (Figure 9-5). However, all data fall
within ±2 standard deviations. Data from the lower
reach (flow > 1 mVsec) are within ±1 standard
devition. The residual number of taxa have a narrower
range (28) among stations than do the original data
set (range - 42 taxa). The implications of these
findings are that variation in number of taxa in the
upper reach is more related to river flows than that in
the lower reach, and differences in number of taxa
along the river gradient need to be interpreted in that
context. However, a number of other changes are
associated with increased flow, for example more
habitat types, increased effluent concentrations, and
higher dissolved solids. There are no data to indicate
which of the many changes caused the effects on the
macroinvertebrates and flow may or may not be
among the causes.
9.4 Evaluation of the Macroinvertebrate
Community
A general degradation of the benthic community
along the river gradient from N2 to N12 was
suggested by the spatial trend of the community
parameters (diversity and community loss) and the
distribution of certain benthic taxa. This downstream
trend of decreasing health of the benthos could be
attributed to the combination of two primary factors.
First, the cumulative input of industrial effluent and
serial positioning of the discharges has not only
localized effects but prohibits effective recolonization
downstream. Secondly, and perhaps more important-
ly, the flow regime of the river substantially increases
from N2to N12 causing shifts in habitat quality from
upstream to downstream. The flow at N12 was more
than 50 times greater than that measured at N2
(Table 6-3). These flow differences along with periodic
regulation of the river, alters the habitat to which the
organisms are exposed.
Results of the community parameters best reflected
effects from individual discharges. Direct effects
were attributed from these data to the Gulf Stream
and Mad River tributaries, the Torrington and Nauga-
tuck POTWs, and the Thomaston Dam. Direct dis-
charge effects were not as apparent from the benthic
population data. A degree of intermediate recovery of
the benthos was noted along the river gradient from
the community parameter data resulting in a division
of the study area into "reaches." The upper reach
contained the healthiest benthic community and
extended from the N1 upstream of Torrington to
Station N5 located downstream of the Thomaston
POTW. The middle reach reflected a lower quality
community and extended from Station N6 located
downstream of Steele Brook to Station N8 down-
stream of the Mad River. The lower reach had the
9-9
-------
Figure 9-6. Residuals (actual minus predicted number of benthic taxa) versus river flow.
-10-
+1 S.D.
A A
5-
0-.
-5-
-1 S.D.
-10-
-15-
-20-
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4
Flow
2.6 2.8
3.0
poorest quality benthic community and extended
from Station N9 downstream of the WaterburyPOTW
to Station N12.
Certain other factors such as predation and grazing
pressure (competition) may have had some influence
on the quality of the benthos. These factors were not
investigated but are believed to have had little
influence on the structure of the benthic community
in comparison to the observed effects due to dis-
charges and habitat.
9-10
-------
10. Fish Community
Investigation of the fish community of the Naugatuck
River was used as another measure of the community
condition of the river. The objective of the fisheries
investigation was to collect, identify, and count fishes
from locations throughout the Naugatuck River
watershed and examine the resulting data for evi-
dence of response to known point-source discharges.
The methods used for the fisheries survey are
presented in Appendix D.
10.1 Community Structure
The fisheries survey of the Naugatuck River water-
shed yielded nearly 4,000 specimens from eight
families and 22 species (Tables 10-1 and G-7). The
minnow family was dominant with the blacknose
dace as the most abundant species (Table 10-1).
, White sucker was the second most abundant species
collected, but was the only representative of the
sucker family. The thjrd most abundant species was
the tassellated darter of the perch family.
The distribution of the fish species among the
sampling stations exhibit three general trends. Spe-
cies distribution and abundance data indicate that
different communities exist in the tributaries and in
the upper and lower Naugatuck River. The species
differences appear to be due to physical habitat
changes as well as influences from effluent dis-
charges. The differences between the three areas
sampled are shown by examining the numbers of
species and individuals collected (Table 10-1). Based
on a chi-square analysis, Stations N6, N8, N10, and
N12 were significantly (P < 0.05) lower than the
maximum number of species found at Station N5. The
maximum number of species was considered reflec-
tive of optimum conditions and therefore used as the
expected value. The mean number of individuals
collected at the-upstream Naugatuck River stations
was four times greater than at the tributary stations
and 10 times greater than at the lower Naugatuck
River stations (474 vs. 115 vs. 45). In addition, the
mean number of fish species collected at the upper
Naugatuck River stations was twice as high as either
of the other two areas (11 vs. 5 vs. 6).
In the tributary stations, fewer species and numbers
of individuals were collected. This occurrence may be
due either to limited habitat or known point-source
discharges. The Beaver Pond Brook Stations, BP1 and
BP2, produced relatively few species in low to
moderate numbers (Table 10-1). This appears to be a
result of habitat limitation rather than upstream
discharges. Beaver Pond Brook was shallow and
narrow (5.2 m) and thus did not have the physical
habitat available to hold a large number of fishes,
despite apparent good water quality. Gulf stream and
Steele Brook (Stations GS1 and SB1, respectively)
were similar in habitat to Beaver Pond Brook, but no
fish were collected at Station GS1 and only three
were collected at Station SB1. This may be due to
point-source discharges upstream. The Mad River
tributary was larger and offered a greater diversity of
habitat than the other tributaries. This was reflected
in the greater number of species and specimens
captured at Stations M1 and M2. Fishing efforts at
Station M5, which contained good fish habitat,
produced no fish. The water at Station M5 contains
the combined effluents of several upstream industrial
discharges. The upper Naugatuck River stations, from
Station N1 atTorrington to Station N5 at Waterbury,
represent a second type of habitat in terms of fish
species composition and abundance (Table 10-1). The
combination of greater amount of physical habitat
(relative to tributaries) and fewer sources of polluted
effluents accounts for the larger number of fish at
these locations. Although there are differences in
individual species among the upper Naugatuck River
stations, they are largely attributable to microhabitat
differences. Minnows, white sucker, and tessellated
darter dominated catches. Sunfish occurred in very
low numbers at these stations, except at Station N5.
Stations N2 and N3 were wide and shallow and
lacked the depth and cover necessary to support
sunfish. The cutlips minnow occurred only at Stations
N2 through N4A. Their absence downstream may be
attributed to their sensitivity to turbidity and siltation
(Scott and Grossman 1973; Cooper 1983); however,
absence from the tributaries and at Station N1 is
unexplained except that the average stream flow may
have been too high for this reportedly sluggish
minnow.
Other differences in catches of a species among the
uypper Naugatuck River .stations are evident. For
example, tessellated darters were uncommon at
Stations N1 through N3 relative to Stations N4
through N5. This may be explained at least in part by
the poorly developed riffles at Stations N2 and ftJ3
10-1
-------
Table 10-1. Numbers of Fish Collected from the Naugatuck River and Tributaries in Connecticut, 1983
Naugatuck
Sampling Station
Spocies
American eel
Brown trout
Chain pickerel
Rodfin pickerel
Common shiner
Spottail shiner
Creak Club
Fallfish
Longnose dace
Slackness dace
Cut lips minnow
Golden shinor
White sucker
Brown bullhead
Yellow bullhead
Bluegill
Pumpklnseod
Redbreast sunfish
Rock bass
Lirgemouth bass
Suntish sp.
Yellow perch
Tessellated darter
Crayfish
Total Number of Fish
Chi-square (Xs)*
No. of Taxa
N1
1
5
1
31
20
9
19
5
1
2
7
6
24
107
0.76
12
N2
67
32
14
9
677
71
38
18
51
926
3.52
8
N3
15
19
22
17
49
43
24
8
138
198
3.52
9
N4
2
58
87
25
1
1
50
4
|
2
1
40
62
268
1.27
11
N4A
1
15
42
262
119
14
6
96
1
I
5
7
252
100
823
0.39
13
N5
1
1
3
3
14
57
9
4
174
3
no
^O
12
58
1
152
131
526
0
16
N6 N7
3
1
1
3
1
2
6 2
1
•j
2 2
1
1
11
5 15
7 94
17 41
6.89" 0.76
5 12
N8 N9
5
8
2
26
62
24
3
13
1
2 8
69
19 23
6 217
9.77" 2.64
3 9
N10 N11 N12 BP1
2 1
9
5
3 8
1
2 7
1 1
2
1 1
1
9 15
15 16 1 34
• 4 29 4 33
9.77 3.52 y.//
383 4
Tributaries
Sampling Station
BP2 GS1 SB1
1
17 1
7
35
1
1
3
55 1
15 5
1190 3
703
M1
3
41
64
4
3
1
254
2
41
6
12
78
431
11
M2
1
1
35
73
20
36
17
1
30
4
1
55
219
11
M5
2
0
0
'Expected value = 16 (maximum number). X2 not calculated for tributaries.
•Significantly lower (P Ł0.05) from Station N5
relative to N4A, and the consequent better darter
habitat at Station N4A.
Beginning with Station N2 and extending down-
stream, there is a third change in the fish community.
Although the number of species captured differed
greatly among these downstream stations, the num-
ber of specimens captured was still markedly lower
than at upper Naugatuck River stations. In addition,
the number of different species collected at the
downstream stations declined relative to those
stations in the upper Naugatuck River. From Station
N6 to N12, the number of species and individuals was
lowerthan at upstream stations, with the exception of
station N9.
10.2 Evaluation of Fish Community
Response
The fish survey was conducted and the results were
analyzed, independent of the effluent configuration
and toxicity testing carried out concurrently and
presented in this report. By excluding information on
effluent concentrations and toxicities, the field data
may serve as an independent confirmation test for the
other studies. The catch from this study of 22 species
70-2
is quite representative of the historically documented
fish community in the Naugatuck River. Whitworth et
al. (1968) reported less than 30 fish species in the
Naugatuck watershed, based on a state-wide survey
in 1965-1967 and other extant records. This is a
rather low number of species, given the size of the
stream, but is a result of the greater effect of
glaciation in this area as well as the relatively poor
productivity of New England streams in general
(Gilbert 1980).
To provide the best comparison of the fish results
among sampling stations, the catch data were con-
verted to total number offish per 93 m2(Figure 10-1).
Although one 91.4-m length of stream was sampled
in all but one case, the stream widths differed greatly
(Table C-1) and consequently, the actual size of the
areas sampled differed among stations—by an order
of magnitude between Stations BP1 and N10. The
calculation of fish per 93 m2 provides a more precise
comparison between stations when assuming that
the carrying capacity of a stream section is directly
proportional to its size.
The catches in the upper Naugatuck River, although
variable, were indicative of an abundant, diverse fish
-------
community from Station N1 downstream through
Station N5 (Figure 10-1). While the differences in
catches among upper stations may be influenced by
point-source effluents, it is probable that these dif-
ferences are due primarily to variation in available
microhabitat among the stations. After Station N5,
the Naugatuck River fish community changes notice-
ably. These data suggest that the fish community in
Steele Brook and in the Naugatuck River below the
confluence with Steele Brook is stressed. This stress
on the fish community does not dissipate for some
distance downstream. The moderate recovery of the
fish community at Station N9 may be a function of
distant downstream from the major effluent sources.
However, this recovery is short-lived, as fish were
essentially absent at Stations N10 through N12.
The Gulf Stream tributary, which enters the Nauga-
tuck River between Stations N2 and N3, was sampled
in its lower reach and no fish were captured. This
tributary is apparently greatly affected by upstream
effluents. Similarly, Steele Brook produced onlyafew
fish. In this tributary, a greenish deposit was noticed
on the substrate that may have originated from any of
several upstream dischargers.
Sampling in Beaver Pond (Stations BP1 and BP2)
revealed a good fish community for the stream size
(Figure 10-2). The community was not noticeably
affected by known point-source effluents down-
stream of Station BP1. The upper Mad River (Stations
M1 and M2) also produced good catches in terms of
species and individuals. However, at Mad River
Station M5 just prior to the juncture with the
Naugatuck River, no fish and only two crayfish were
captured. The most plausible explanation for this is
the effect of industrial dischargers in the lower Mad
River.
Figure 10-1. Abundance and number of species of fish captured from the Naugatuck River, Connecticut.
70-i
Abundance
E
po
(D
-Q
E
•o
c
=1
.Q
Number of Species
Abundance at Tributary Stations
Number of Species at Tributary Stations
2 3
Sampling Stations
10-3
-------
Figure 10-2.
70-1
Number of fish captured inthe Mad River,
Connecticut.
60-
co
O
ex
ro
O
•S
E
D
z
virtually no fishes...south of that city." They attributed
this condition to the effect of domestic and industrial
effluents. Judging by this fish community, the present
survey demonstrates that river conditions have
improved downstream at Torrington but that the
effluent loading in the Waterbury area prohibits the
recovery of the fish community from Waterbury
downstream at least as far as Ansonia and perhaps as
far as the juncture with the Housatonic River.
10
BP1
BP2 M1 M2
Sampling Stations
The presence of a relatively abundant and diverse fish
community in the Naugatuck River between Torring-
ton and Waterbury represents an improvement over
recent historical conditions. In their state-wide
sampling survey during 1965-1967, Whitworth et al.
(1968) reported finding in the Naugatuck River, "a
varied and large fish fauna..above Torrington and
10-4
-------
/ /. Comparison Between Laboratory Toxicity Tests and Instream Biological Response
11.1 Background
The comparisQn between toxicity measured in the
laboratory on a few species and the impact occurring
in the stream on whole communities must compen-
sate for a very limited database from which to predict.
The sensitivity of the test species relative to that of
species in the community is almost never known and
certainly not in these toxicity tests. Therefore, when
toxicity is found, there is no method to predict
whether many species in the community, or just a
few, will be adversely affected at similar concentra-
tions, since the sensitivity of the species in the
community is not known. For example, at a given
waste concentration, if the test species has a toxic
response and if the test species is very sensitive, then
only those species in the community of equal or
greater sensitivity would be adversely affected by
direct toxic effects. Conversely, if the test species is
tolerant of the waste, then many more species in the
community would be affected at the concentration
which begins to cause toxic effects to the test species.
It is possible that no species in the community is as
sensitive as the most sensitive test species, but since
there are so many species composing the community,
this is unlikely. It is more likely that a number of
species in the community will be more sensitive than
the test species. The highest probability is that the
test species will be near the mean sensitivity of
organisms in the community if the test species is
chosen without knowledge of its sensitivity (as was
the case here).
In a special case, where toxicants remain the same
and the species composing the community remain
the same, the number of species in the community
having a sensitvity equal to or greater than the test
species also will remain the same. As a result, there
should be a consistent relationship between the
degree of toxicity as measured by the toxicity test and
the reduction in the number of species in the
community. In this special case, there should be a
tight correlation between degree of toxicity and the
number of species. If the toxic stress is great enough
to diminish the production of offspring by a test
species, it should also be severe enough to diminish
the reproduction of some species within the com-
munity of equal or greater sensitivity. This should
ultimately lead to elimination of the more sensitive
species if the reduction is large enough. Therefore, a
lower number of taxa should be a predictable
response of the community. For example, there
should be a relationship between the number of
young per female Ceriodaphnia or the growth of
fathead minnows (or other test species) and the
number of species in the community. Obviously, the
test species must have a sensitivity, such that at
ambient concentrations to which the community has
responded, a partial effect is produced in the toxicity
test. However, unless the special case described
above exists, the correlation between toxicity and
species richness will not be a tight one.
Effluents differ from single chemicals in some
important respects. We know from the literature on
single chemicals that there usually are large dif-
ferences in the relative sensitivity of species to a
chemical and that the relative sensitivity changes
with different chemicals. For exmaple the fathead
may be more sensitive to effluent A and Ceriodaphnia
more sensitive to effluent B. We also know that
effluents vary in their composition from time to time
and often within a few hours. We should not be
surprised therefore to find fathead minnows being
more sensitive to an effluent on one day and daphnids
more sensitive on another day.
Effluents begin changing in composition as soon as
they are discharged. Fate processes such as bacterial
decomposition, oxidation, and many others change
the composition. In addition, various components will
change at different rates. For example, ammonia
would be expected to disappear more rapidly than
PCBs. If so, then the composition of the effluent is
ever changing as it moves through the receiving
water. Note that this change is not just a lessening
concentration as a result of dilution but also a change
in the relative concentrations of the components. In
reality, the aquatic organisms at some distance from
the outfall are exposed to a different toxicant than
those near the discharge pointl Therefore, it is logical
to expect that sometimes one test species would be
more sensitive to the effluent as it is discharged and
another species more sensitive after fate processes
begin altering the effluent. To be sure, the source of
the effluent is the same but it is certainly not the same
"effluent" in regard to its composition. If these
statements are true then one should also expect that
species in the community in the receiving water may
be affected at one place near the discharge and a
11-1
-------
different group of species may be affected from the
same effluent at another location.
An effluent cannot be viewed as just diluting as it
moves away from the outfall. In fact, it is a "series of
new effluents" with elapsed flowtime. If so, there are
important implications for interpretation of toxicity
and community data. One should not expect the
various test species to respond similarly to water
collected from various ambient stations. We should
expect one species to be more sensitive at one station
and another species to be more sensitive at the next.
The affected components of the community should
vary in a like manner.
An even bigger implication is that the surrogate
species concept is invalid in such a situation. As one
examines the community data in the Lima report
(Mount etal., 1984) and in subsequent studies in
press, it is clear that there is no one community
component that is consistently sensitive. Sometimes
the benthic invertebrates and the periphyton have
similar responses and both are differentfrom thefish.
Sometimes the fish and periphyton have similar
responses and these are unlike the benthic inverte-
brates.
The same is true of the test species. Sometimes the
Ceriodaphnia respond like the periphyton and other
times like the fish. The important point is that a
careful analysis of our knowledge of toxicology,
effluent decay, and relative sensitivity tells us that we
cannot expect:
1. Ceriodaphnia toxicity to always resemble tox-
icity to benthic invertebrates
2. Fathead minnow toxicity to always resemble
toxicity to fish
3. Fathead minnows and other fish to display the
same relative sensitivity to different effluents.
Any test species should have a sensitivity repre-
sentative of some components of the community. The
important distinction is that one never can be sure
which components they will represent.
In comparing toxicity test results to community
response, comparison must be made with the above
in mind. Certainly those community components that
are most sensitive will be most impacted and/or lost.
The response of the most sensitive test species
should therefore be used to compare to the response
of the most sensitive of the community.
A weakness in using the number of species as the
measure of community response is that species may
be severely affected yet not be absent. The density of
various species is greatly influenced by competition
for available habitat, predation, grazing, and/or
secondary effects which may result from changing
species composition. Density is more subject to
confounding causes, other than direct toxicity, and is
not as useful as the species richness in the com-
munity to compare community response to measured
toxicity.
Several measures of co'mmunity structure are based
on number of species, e.g., diversity and community
loss index. Since diversity measures are little affected
by changes in the number of species (or taxa) that are
in very low densities in the community, diversity is an
insensitive measure for some perturbations which
can be measured by toxicity tests. The community
loss index is based only on the presence or absence of
specific species relative to a reference station and
would be useful except that habitat differences
between stations heavily affect this measure. There
are several problems when using the number of (taxa)
species measured. The foremost is that the mere
presence or absence of species is not a compre-
hensive indicator of community health, especially if
the species are ecologically unimportant. Secondly, a
toxic stress may not eliminate species but yet have a
severe effect on density; presence or absence does
not consider such partial reductions. The presence or
absence of species as the measure of community
impact is influenced by the chance occurrence of one
or a few individuals due to either drift, immigration, or
some catastrophic event when in fact that species is
not actually a part of the community where it is found.
Effects other than toxicity, such as habitat, will
always confuse such comparisons to toxicity data to
some extent. Use of artificial substrates should
reduce habitat effects compared to natural sub-
strates. They cannot be eliminated. Identification of
taxa to different levels can reduce the sensitivity of
species richness.
Even though species richness has numeroussources
of error as a representative measure of community
health, it remains the best measure for comparison
with toxicological data. Species sensitivity will re-
spond in the most direct way to toxic response of the
community with the least interference.
11.2 Comparison of toxicity and Field
Data for Naugatuck River
11.2.1 Effluent Tests
The need to provide the data for the mass balance
modeling efforts required that the effluent tests had
to be performed using water from station N1 rather
than immediately upstream of each outfall. In a
complex situation such as this site with many
discharges, the characteristics of the water quality
change with additional dischargers. This is illustrated
in two ways.
In the work for the site-specific criteria development,
Carlson et al. (1986) found that copper was 3.2 and
77-2
-------
7.1 times less toxic at Stations N4A, N5, N6, and N7
as compared to Station N1. In this report, for example,
Steele Brook produces an instream waste concentra-
tion of 15.7% at Station N6 (Table 6-4). The AEC for
daphnids of Steele Brook water is 1.7 and 5.5% (Table
5-15). The instream waste concentration exceeds the
AEC by 3 to 8 times, yet the ambient toxicity at Station
N6 was not measurable on 5 of 7 days of the testing
period (Table 4-2).
Since metals, especially copper (Carlson et al.. In
preparation), were found to be important toxicants at
this site, the addition of POTW effluent would be
expected to reduce metal toxicity. Because the tests
on effluents were not done on water immediately
upstream of each discharge, the effluent test data are
not useful for predicting effects downstream of the
effluent discharge point. However, should the regu-
latory strategy be such that the safety of one
discharge should not be dependent on the presence
of another, then the effluents should be diluted with a
water such as N1 to determine acceptable effluent
concentrations.
11.2.2 Ambient Toxicity
Figure 11-1 is a plot of the ambient toxicity data for
both test species. The data for daphnids and fatheads
represent a different exposure condition. The fat-
heads were exposed to a different water sample for
each 24-hour period whereas the daphnids were
exposed to the same sample for the entire seven-day
test period. The daphnid values plotted are the means
of seven such tests using samples collected on seven
successive days. The daphnids show a trend of
declining young per female from upstream to down-
stream. The fatheads show a similar trend except at
Station N9 where there was little toxicity to the
fatheads. The total mortality of fatheads at Stations
10 and 11 resulted from a toxic slug from the
Naugatuck POTW. Since the fatheads were exposed
to a new sample every day, once killed by a single
day's sample, the toxicity of succeeding day's samples
could not be measured. Similar types of tests were
done using Ceriodaphnia (Table 4-3) and they were
also all killed at Stations N10 and N11. At Station N12
all daphnids were killed (Table 4-3) but mean survival
of fatheads was 53% (Table 4-1) indicating the
fatheads were less sensitive than daphnids to the
toxic slug. The data points in Figure 11-1 for daphnids
are derived as a mean of seven mass balance type
tests (Table 4-2) and the toxic slug lowered the mean
value, but after it passed, young per female was much
higher. Considering the different exposure condi-
tions, the two test species have the same trend except
for Station N-9.
Figures 11-2 and 11-3 are plots of the number of taxa
forperiphyton, benthicmacroinvertebrates, zooplank-
ton, and fish. Except for zooplankton, there is a trend
Figure 11.1
Toxicity of ambient station water to fathead
minnows and Ceriodaphnia, Naugatuck River.
Ł• 2: Łr
8 S 3
CO
Ł
g>
'to
o
c
c
0.50
0.40
0.30
0.20
0.10
O
0.
O -c 'C -c
Q Q. K I- I-
O O
Q- O_
I I U M I I I
X
o>
c
C
ID
=.
D3 = gŁ
=§ € •§ 5 5
__-.-
I (HIM » f
20 r
!
|lB
i
; 10
i
i
i 5
32
J.
Q.
.16 '5
Q.
8 |
3
3 4 56 7_ 8 9 10 11 _i 2
Stream Station (64 km stretch)
of decreasing taxa from upstream to downstream,
trends that resemble the ambient toxicity data shown
in Figure 11-1. The zooplankton data are different.
The zooplankton investigators attribute the increased
density and taxa at Stations N5, N6, N7, and N8 to the
effects of the impoundment. One might expect, if so,
that Station N5 would be the highest followed by a
decline at downstream stations, which was not the
case.
If toxicity occurs that takes time to be expressed, then
one would expect the drifting zooplankters to show
effects somewhat downstream of the point of dis-
charge. This would explain the drop in taxa between
stations N8 and N9. From Table 4-2, one can see that
11-3
-------
Figure 11.3. Number of benthic and zooplankton taxa at
various stream stations, Naugatuck River.
I I H f f I I I
10 11 12
Stream Station (64 km stretch)
Station 8 water was lethal every day but one whereas
Station N9 water was less toxic. The populations
enumerated at Station N9 may have been intoxicated
at Station N8 and then disappeared as they drifted to
Station N9. The absence of zooplankton at Station
N12 agrees with observed toxicity. Although Station
N12 was run as an impact test, new animals were set
up in each day's samples and they were killed within
24 hours in every case. The ambient test data do not
agree with the few species found at Station N1 but
the stream was small atN1 and one would not expect
zooplankton to be abundant as a result of habitat—not
toxicity. The substantial increase at Station 2 may be
a result of an impoundment on a tributary upstream of
that station.
The data for the toxicity test and for the number of
taxa showthesametrendsexceptfor zooplankton. To
make a more quantitative comparison. Table 11-1
was compiled by using the highest number of young
per female or the largest weight as 0 toxicity for the
daphnids and fatheads, respectively. Toxicity for other
stations was then calculated as a percent of those
reference values. The reduction in number of taxa
was calculated in a similar way. Thus the reference
stations were different among the various measures.
Table 11-2 was then constructed from Table 11-1 in
the following way. If both toxicity values for a station
were below 20% and all four taxa values were below
20%, a correct prediction was registered. If one or
more toxicity values and one or more taxa values
were over 20%, a correct prediction was counted.
This was done for all stations and the percent correct
prediction placed in the upper left cell of Table 11 -2.
The same procedure was used for each cell only
changing the percentage used to the appropriate
value for that cell.
The highest percentage of correct predictions were
obtained when 20 percent was used for toxicity and
20 or 40 percent for the field data. Eighty-five percent
of the stations were correctly predicted. One can also
see that the largest percentage of correct predictions
were obtained when comparable percentages were
compared, i.e., the highest values lie along a diagonal
from upper left to lower right. This pattern is evidence
that the degres of toxicity is related to the degree of
taxa reduction. To verify this trend qualitatively, the
degree of toxicity and reduction of taxa was subjected
to a correlation analysis. The correlation was signif-
icant (P < 0.05) for daphnids with periphyton,
macroinvertebrates, and fish but not zooplankton.
Since there were no fathead minnow data at three
stations, correlations were not done with that data.
11.3 Summary
The toxicity data reflected the same trend as the field
data for three groups of organisms. The correlation of
daphnid toxicity data with periphyton, macroinverte-
brates, and fish species richness was significant (P <
0.05). When percent toxicity and taxa reduction were
compared in a matrix, up to 85% of the stations were
correctly predicted.
11-4
-------
Table 11-1.
Percent Increase in Toxicity and Reduction in Taxa for Each Ambient Station Using the Least Toxicitv or Largest
Number of Taxa as Zero Percent
Station
1
2
3
4
4A
5
6
7
8
9
10
11
12
Ceriodaphnia
12
4
20
0
24
6
22
58
94
50
39
100
100
Fathead
Minnows
20
21
—
0
--
—
18
32
70
17
100
100
63
Algae
0
11
41
33
0
0
44
48
56
41
56
44
52
Zooplankton
92
33
42
67
67
25
0
0
8
75
67
25
100
Benthic
Macro-
Invertebrate
0
44
10
21
32
51
59
68
69
58
68
69
65
Fish
25
50
44
31
19
0
69
25
81
44
81
50
81
Source: Tables 4-1 to 4-3, 8-2, 10-1, G-1, G-6, and 10-1.
Table 11-2. Percent Correct Predictions of Impact Using
Four Levels of Comparison
Combined Field Data (Percent)
Combined
Toxioity
Data
20-100
40-100
60-100
80-100
20-100
85
38
23
23
40-100
85
38
23
23
60-100
77
62
46
46
80-100
46
62
77
77
Source: Table 11-1
11-5
-------
-------
References
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R-2
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Appendix A
Onsite Toxicity Test and Analytical Methods
Two types of effluent and ambient toxicity tests were
conducted for the Naugatuck River study. One set of
tests was termed the "impact tests" in which the test
organisms were exposed to a new effluent or ambient
stream station sample each day for seven days. The
other set of tests was termed the "mass balance
tests" (as the results were to be used in a mass
balance model of toxicity) in which the entire test was
completed on the same sample. In this test, the tests
solutions were renewed only twice, in contrast to
daily, and the sample was kept refrigerated for the
duration of the test. Seven such tests were run on
each of seven ambient station samples for each
exposure condition. This type of exposure is less
representative of the exposure of the organisms in
the receiving water.
A.1 Sampling Preparation
Sampling of each effluent and ambient stream station
was done using the ISCO samplers. An aliquot was
collected every 15 minutes and composited into a
5-gal polyethylene container. About 18 L were col-
lected every 24 hours and new samples were taken
each day. However, aliquots of Stations N6 and N7
water were collected manually every 4 hours. The N1
water used for dilution was collected in 5-gal poly-
ethylene containers as a daily grab. Due to collection
difficulties, the following stations on the specified day
were grab samples: Station N3 on 23, 24, and 27
August, Station N4 on 28 August, Station N4A on 29
August, Station N9on 24August, and Station N1 Aon
23 August.
A.2 Fathead Minnow Tests
Only impact tests were performed on the fathead
minnows. Three POTW effluents were tested at
concentrations of 1, 3, 10, 30, and 100 percent. Two
tributary streams (Mad River and Steele Brook) that
each had several discharges were tested as effluents,
using water collected at the mouth of each tributary.
The same dilution sequence was used. The source of
dilution water was the most upstream ambient
station, Station N1, which was upstream of all known
dischargers.
For ambient toxicity tests, stations were established
over the distance of the river from Station N1 to near
the river mouth. Stations were selected to measure
the impact, if any, of the various effluents and
tributaries.
Larval fathead minnows were less than 24 hours old
and were air-shipped from the Newtown Fish Toxi-
cology Station. The fish were assigned one or two at a
time to replicate test chambers until all replicates had
10 fish in each chamber or 40 fish per concentration.
Test tempertures were 25 ± 2°C, and were main-
tained by control of the air conditioner and furnace.
Newly hatched brine fish were fed to the fish twice
per day. The uneaten shrimp were removed daily by
siphoning the chambers during test renewal. At that
time the test water was also drawn down to a depth of
approximately 1 cm, and 2 L of new test solution were
added. Effluent dilutions were made using polypro-
pylene graduated cylinders of various sizes and
mixing was done in 4-L polyethylene beakers. Initial
dissolved oxygen (DO), pH, and conductivity measure-
ments were taken before the test solutions were
added to the test chambers. Prior to renewal, DO was
measured again and recorded as the final value.
After seven days of exposure the fish were removed
and preserved in 4 percent formalin. On returning to
the laboratory, the fish were rinsed in distilled water,
oven-dried for 18 hours in preweighed weighing
pans, and weighed on a five-place analytical balance.
The methods followed those described in Norberg and
Mount (1985).
A. 3 Cerio daphnia Tests
Adult Ceriodaphnia sp. from the ERL-D culture were
transported by air to the study site and transferred to
Station N1 water. One adult each was placed in 15ml
of dilution water in a 1 oz clear plastic cup. Each day
the adult was removed and transferred to new water.
The young produced from these adults were used for
the toxicity tests when they were 0-4 hours old. Since
the mass balance tests were initiated daily (each day
for 7 days), young animals were needed every day.
Therefore, adults were maintained as described
above to constantly provide new test organisms.
Because the various industries discharge on a 5-day
per week schedule, the results of the Ceriodaphnia
mass balance tests were not expected to be the same
over the seven day test period. Both mass balance and
impact tests were conducted using Ceriodaphnia.
A-1
-------
A drop (~ 0.05) of a yeast suspension containing 250
ywg of yeast was fed to each adult daily. In the impact
tests, the test animal was transferred to a new test
solution on day 2 and 4 at which time any young
present were counted and discarded. The effluent
sample for the impact test was stored at < 4°C until
each renewal. At that time the test cups were filled
with 15 ml of test solution and slowly warmed to room
temperature. Final DO was measured in one of the
ten cups for each treatment at each renewal. The
methods used generally followed those of Mount and
Norberg(1984).
A.4 Quantitative Analyses
A.4.1 Ceriodaphnia
The statistical analyses of the data were performed
using the procedure of Hamilton (1984) as modified
by Rogers (personal communication). In this proce-
dure the young production data were analyzed to
obtain the mean number of young per female per
treatment. Daily means were calculated and these
means were summed to derive the 7-day mean young
value. By this method, any young produced from
females that die during the test are included in the
mean daily estimate. Using this procedure, mortal-
ities of the original females affect the estimate
minimally, but the mortality of the adult is used along
with the young production to determine overall
toxicity effects. Confidence intervals are calculated
for the mean reproductivity using a standard error
estimate calculated by the bootstrap procedure. The
bootstrap procedure subsamples the original data set
(n = 999) by means of a computer to obtain a robust
estimate of standard error.
A Dunnett's two-tailed t-test is performed with the
effluent test data to compare each treatment to the
control for significant differences. For the ambient
station data, Tukey's Honestly Significant Difference
Test is used to compare between stations.
A .4,2 Fathead Minno ws
The four groups' mean weights are statistically
analyzed with the assumption that the four test
chamber compartments behave as replicates. The
method of analysis assumes the variability in the
mean treatment response is proportional to the
number of fish per treatment. MINITAB (copyright
Pennsylvania State University 1982) was used to
estimated a t-statistic for comparing the mean
treatment and control data using a weighted regres-
sion with weights equal to the number of measure-
ments in the treatments. The t-statistic is then
compared to the critical t-statistic for the standard
two-tailed Dunnett's test (Steele and Torrie 1960).
The survival data are arcsine-transformed prior to
conducting the regression analyses to stabilize any
variances in the percent data.
A -2
-------
Appendix B
Off site Toxicfty Test and Analytical Methods
B.1 Test Program
Due to the number of tests involved, the laboratory
testing program with Ceriodaphnia was divided into
two phases: Phase I—upstream tributaries and
effluents; Phase II—downstream effluents and ef-
fluent/receiving water mixtures. In addition, a meth-
odological variability study was conducted just prior
to Phase I to provide an estimate of inherent test
variability which may be expected due to differences
in organism sensitivity and/or handling of test
organisms and performance. The methodological
variability study consisted of seven replicate Cerio-
daphnia tests conducted simultaneously using a
single sample of the Waterbury POTW effluent.
Water from Station N1 collected each day as a grab
sample was used as the dilution water for preliminary,
Phase I and Phase II, Ceriodaphnia tests. Newly
released neonates (< 8 hours old) were used to
initiate the tests.
For Phase I seven mass balance effluent dilution
Ceriodaphnia toxicity tests (each with five concen-
trations and a dilution water control with ten repli-
cates per treatment) and two mass balance ambient
toxicity tests (see Appendix A for details of test
methodology) were initiated daily for seven consec-
utive days (Days 1-7; 24-30 August). Twenty-four
hour composite samples were collected daily and
shipped air freight to the laboratory in Baltimore. A
test was initiated with each fresh sample, which was
then stored at 4°C for subsequent use in Day 2 and
Day 5 solution renewals. Prior to use, all samples
were passed through 100 mesh Nitex screen to
remove planktonic organisms.
The Phase I mass balance effluent dilution Cerio-
daphnia toxicity tests were initiated with Torrington
and Thomaston POTWs, and five samples tested as
effluents (Gulf Stream, Steele Brook, Great Brook,
Mad River, and Station N8). Two mass balance
ambient toxicity tests were run with daily samples of
Stations N9 and N10. These tests corresponded to
tests performed,onsite (Chapter 4) and were intended
to serve as internal calibration between tests con-
ducted between onsite and offsite testing. Split
samples for onsite and offsite testing were used
during Phase I. Also, N9 was a grab sample on 24
August and N10 was a grab sample on 23 August.
During Phase II (Days 8-14, 31 August to 6 Sep-
tember) five mass balance effluent dilution toxicity
tests and two mass balance ambient toxicity tests
were initiated daily. Mass balance effluent dilution
tests were conducted on the Waterbury POTW, the
Naugatuck POTW, and Station N8 using N1 water as
the diluent for all tests. In addition, tests were done on
the Waterbury POTW mixed with Station N8 water
and the Naugatuck POTW mixed with N9 water. Both
of these tests were then diluted with N1. The 100
percent solutions of these latter tests were prepared
on the proportional POTW/ stream flows measured
on the day the sample was collected. The two mass
balance ambient toxicity tests with Stations N9 and
N10 were repeated during Phase II to continue the
calibration during Phase I. The mass balance effluent
dilution toxicity tests performed with Station N8
water performed during Phases I and II was done to
provide information on whether there was a change
in the stream toxicity over the two-week sampling
and testing period.
B.2 Toxicity Test Data Analysis
The Ceriodaphnia 7-day test, which is primarily
intended to assess the chronic toxicity of a test
material by detecting differences in cumulative young
production over the test period, also yields data on
mortality caused by toxicant exposure.
In addition, the Acceptable Effluent Concentrations
(AEC) was determined for each test based on the
mean young production at each test concentration.
Estimates of mean young production per treatment
group were calculated using the procedure of Ham-
ilton (1984 as modified by J. Rogers [personal
communication, ERL-Duluth]). Details of this pro-
cedure are discussed in Appendix A (Section A.4.1).
The AEC is determined by taking the geometric mean
of the No Observed Effect Concentration (NOEC) with
no adverse effect and the Lowest Observed Effect
Concentration (LOEC) which has an adverse effect.
Conductivity, pH, hardness, and alkalinity were
measured in each sample received. Table F-1 lists the
ranges in those parameters for each of the sample
points. Table F-2 contains the results of the routing
water chemistry measurements taken during the
tests. Measurements were taken on the dilution
water control, low, medium, and high test concen-
B-1
-------
tration replicate at test initiation, each renewal and
test termination. All dissolved oxygen (DO) measure-
ments were > 6.5 mg/Iiter. Some of the water quality
measurements on freshly prepared solutions were
taken before the beakers had equilibrated to test
temperature and prior to the addition of test organ-
isms. This results in some lower (e.g., 1 8°C) recorded
temperatures and wider recorded temperature ranges
(e.g., 22.4-28.3°C) than presumably occurred during
the tests.
B-2
-------
Appendix C
Hydrological Sampling and Analytical Methods
C.I Flow Measurements
During the study period of 22 August to 4 September
1983, flows were measured at Naugatuck River
Stations N1 through N1 2, as well as tributary Stations
SB1, GB1, and M5. Flows were measured daily at
Stations N2, N8, and N12. At the remaining stations
the flows were measured approximately every other
day. These measurements were performed using a
Teledyne Gurley "pygmy" flowmeter. A minimum of
10 velocity measurements were made along a
transect at each station unless measurements were
limited by the narrowness of the cross section, such
as at Station GB1. As many as 20 measurements
were sometimes performed at the wider stations. The
water depth was also recorded with each measure-
ment. At stations with depths of less than 0.75 m,
velocities were measured at a depth of 60 percent of
the water column. At stations with depths greater
than 0.75 m, velocities were measured at depths of
20 and 80 percent of the water column and the mean
velocity was used in subsequent calculations. A
volume discharge was calculated for each velocity
measurement by multiplying the velocity times the
cross-sectional area associated with the segment.
The total flow through a transect is the summation of
the flows through each segment along that transect.
As part of the hydrological analyses at the three dye
study sites (Naugatuck POTW, Waterbury POTW, and
Steele Brook), a travel time for an "average" water
particle was estimated between the discharge and
each downstream transect. This was accomplished
by calculating an average cross-sectional velocity at
each transect by dividing the appropriate Naugatuck
Riverflowbythe cross-sectional area of that transect.
The resulting velocities were used in conjunction
with the transect spacing in order to calculate travel
time between each transect.
C.2 Effluent Configuration Dye Study
Dye was injected continuously for approximately 24
hours at each of the three sites to establish an
equilibrium between the injection-point dye concen-
tration and the downstream dye distribution. On the
second day of each study, water samples were
collected at 12 transects extending from 30 m above
to approximately 1,400 m below the point of dis-
charge. The transect locations with respect to the
three discharges are illustrated in Table C-1. The ratio
of the dye concentration at the point of discharge to
the dye concentration in the water samples collected
at the downstream transects represents the dilution
undergone by the effluent. By conducting the studies
from the downstream to the upstream site, contam-
ination of dye from one study area to the next was
avoided.
Rhodamine WT dye was injected at each site by a
Fluid Metering, Inc., precision metering pump. The
injection system was placed at a sufficient distance
from the river to allow complete mixing of the dye and
effluent prior to the point of discharge. The weight of
the dye container was periodically recorded to
monitor the dye injection rate. The Rhodamine WT
dye used in the study will decay in the presence of
chlorine. Sodium thiosulfate, Na2S203, reduced the
chlorine to chloride when present in a concentration
approximately six times as great as the chlorine level.
At the Naugatuck and Waterbury POTWs, a second
Fluid Metering, Inc. precision metering pump injected
an appropriate solution of Na2S2O3. The line from the
dye was inserted through the side wall of the larger
line from the Na2S2O3 such that both solutions were
injected at the same point.
A flow-through Turner Designs fluorometer was set
up where the discharge from the Naugatuck and
Waterbury POTWs enters the Naugatuck River to
provide a continuous record of discharge dye con-
centration. The fluorometer reading was recorded on
a Russtrack strip chart recorder. The temperature at
the discharge was recorded using a YSI probe and an
Esterline Angus strip chart recorder because the
fluorometer reading is temperature-dependent. Prior
to the field survey, the two fluorometers used had
been calibrated over a dye concentration range of
0-200 ppb.
During the instream survey on the second day of dye
injection, water samples were collected in 200-ml
bottles. A sample was taken and the water depth
recorded every 3 m across the transect, except, near a
discharge or at a narrow transect where a 1.5-m
interval was used for greater resolution. A manual
sampler was set to take the water samples 0.2 m (8
in.) from the bottom. When the depth was less than
0.25 m, the sample was taken at middepth. If the
water depth was greater than 0.5m, a second sample
C-1
-------
was taken 0.1 m from the surface. Water samples
were processed on the same day of the instream
survey using a Turner Designs fluorometer in the
discrete sample mode. The fluorometer calibration
was checked with field standards each day it was
used.
The fluorometer data was converted to dye concen-
tration, C(ppb), using the relationship
C(ppb) = SR exp(0.027){T-25)
where
(Equation C-1)
S = slope from the calibration regression for the
appropriate sensitivity scale of the f I uorometer
R = fluorometer reading
T = temperature of the grab sample at the time it
was processed
exp(0.027(T-25)) = correction factor for the tem-
perature dependence of fluo-
rescence (25°C is the reference
temperature)
In a similar fashion, the fluorometer readings from
the discharge strip chart recorder were reduced every
30 minutes for the duration of the study. The
background levels (equivalent dye concentration
fluorescence) measured upstream of the discharge
and in the effluent prior to dye injection were flow-
weighted to determine a background level which was
subtracted from the instream data.
On the first day of each of the three dye studies, a dye
integrity study was performed. Rhodamine WT dye
was added to effluent and upstream river water in
order to make two 50 ppbdye solutions. The effluent
solution for the two POTWs also contained sodium
thiosulfate. Each solution was measured in the
fluorometer immediately after mixing, periodically for
several hours, and one day later. No noticeable decay
was observed in any of the samples.
At the Naugatuck POTW, injection of Rhodamine WT
dye started at 1330 hours on 22 August and
continued until 1430 hours on 23 August. The two
precision metering pumps were connected to a 200
gm/kg container of dye and a 400 g/liter solution of
NazSaOa, respectively, and the combined line lead
through a grate following the chlorine contact
chamber. The resulting dye injection rate was calc-
ulated to be 3.15 g/min over the duration of the study.
The NaaSaOa injection rate of 110 ml/min is equiv-
alent to a 4.7 ppm concentration in a discharge flow of
0.16 mVsec, which would protect the dye from a
chlorine residual of 0.8 ppm. The fluorometer moni-
toring the discharge dye concentration was set up at
the flume approximately 30 m below the dye injection
point.
At the Waterbury POTW, injection of Rhodamine WT
dye started at 1350 hours on 24 August and
continued to 1530 hours on 25 August. The two
precision metering pumps were connected to a 200
g/kg container of dye and a 500 g/liter solution of
Na2S2O3, respectively. The solution was injected at
the flume following the chlorine contact chamber.
The resulting dye injection rate was calculated to be
3.08 g/min over the duration of the study. The
Na2S2O3 injection rate of 260 ml/min is equivalent to
a 2.73 ppm concentration in a discharge flow of 0.79
mVsec, which would protect the dye from a chlorine
residual of 0.46 ppm. The fluorometer monitoring the
discharge dye concentration was set up at the point
where the discharge pipe empties into the Naugatuck
River, approximately 150 m from the point of injec-
tion.
At Steele Brook, injection of Rhodamine WT dye
started at 1020 hours on 26 August and continued to
1230 hours on 27 August. The precision metering
pump was connected to a 200 g/kg container of dye.
The dye was injected into Steele Brook at a distance
82 m above its confluence with Naugatuck River.
During the dye study, the injection rate appeared to
increase uniformly from 2.07 g/min to 2.31 g/min.
The average injection rate was 2.21 g/min. A
fluorometer was not set up to continuously monitor
the discharge dye concentration from Steele Brook
due to the lack of 110 v power and the unsecured
nature of the site. Instead, the discharge dye con-
centration was monitored by collecting grab samples
along a transect 30 m before the confluence.
Table C-1. Transect Locations for Dye Studies at Three
Sites on the Naugatuck River in August 1983"
Transect
TO
T1
T2
T3
T4
T5
T6
T7
T8
T9
T10
T11
Naugatuck
POTW
-30
0
15
30
76
152
229
305
396
610
914
1,219
Waterbury
POTW
-30
0
15
30
76
152
229
305
503
762
1,067
1,433
Steele Brook
-30
0
15
30
76
122-194
229
305
457
701
1,067
1,372
"Distance downstream from the discharge (meters).
' C-2
-------
Appendix D
Biological Sampling and Analytical Methods
D.1 Periphyton
Natural substrates (rocks) in the Naugatuck River (13
stations) and selected tributaries (7 stations) (Figure
2-1) were sampled quantitatively using an epilithic
algal bar-clamp sampler. Samples were taken from
the lower end of riffle areas and runs located at each
station. Three replicate samples were taken at each
station for chlorophyll a and biomass measurements.
A volumetrically measured aliquot was removed from
these samples and filtered using 0.45-fjm filters:
These filters were stored with desiccant on wet ice to
await laboratory analysis for chlorophyll a. The
remainder of each sample was stored in 4-oz. glass
jars on ice to await laboratory analysis for biomass.
One sample consisting of a single bar-clamp collec-
tion was taken from each station for cursory (genus
level) identification and abundance estimates. These
samples were stored in M3 preservative prior to
analysis.
Samples were analyzed for ash-free dry weights
(AFDW) and chlorophyll a concentration. For AFDW,
samples were dried at 105°C to a constant weight
and ashed at 500°C. Distilled water then was added
to replace the water of hydration lost from clay and
other minerals. Samples were redried at 105°C
before final weighing, and standing crop (biomass)
was expressed in grams per square meter (g/m2).
Filters for chlorophyll a analysis were macerated in a
90 percent acetone solution, then centrifuged and
analyzed spectrophotometrically. A chlorophyll a
standard (Sigma Chemicals) extracted in a 90 percent
acetone solution was used for instrument calibration.
Chlorophyll, a standing crop was expressed as milli-
grams per square meter (mg/m2). The biomass and
chlorophyll a data were used to calculate the Auto-
trophic Index (Weber 1973), which indicates the
relative proportion of heterotrophic and autotrophic
(photosynthetic) components in the periphyton. The
chlorophyll a data were also statistically examined by
analysis of variance (Steel and Torrie 1960) and
multiple comparison tests to detect significant dif-
ferences (P <0.05) between sampling locations.
For identification and enumeration, each periphyton
sample was mixed for 30 seconds in a blender to
disrupt algal clumps, and then the sample volume
was increased to 100 or 250 ml. Ten percent of each
thoroughly mixed sample was removed to prepare
Hyrax slides, which were examined at 1,250X
magnification to confirm the identity of diatoms
encountered during the quantitative analyses. A 0.1 -
ml, 0.2-ml, or 0.5-ml aliquot from each quantitative
sample was placed in a settling chamber designed for
use on an inverted microscope. The chamber was
then filled with deionized water, and periphytic forms
were allowed to settle to the bottom of the chamber
for 24 hours. Samples were examined at 1,OOOX
magnification with an inverted microscope, and algae
were identified to genus. For each sample, two or four
diameters of the counting chamber were examined,
and algae containing protoplasm were enumerated
as units. These units were cells except for genera of
filamentous blue-green algae and the large green
algae Cladophora and Oedogonium, which were
counted in 10-//m units of length. The actual number
of units identified and counted in each sample ranged
from 191 to 1,473 but was greater than 300 in all
except two samples. Periphyton abundance was
expressed as number of units per square millimeter
(units/mm2), and taxa diversity and equitability were
calculated from raw counts by U.S. EPA Methods
(EPA 1973).
D.2 Zooplankton
Zooplankton samples were collected by filtering 15-
150 gallons of water through an 8-/um mesh Wiscon-
sin plankton net at each of 13 Naugatuck River
stations and 7 tributary stations. Sample concen-
trates were preserved in 10 percent formalin and
returned to the laboratory for analysis. Three replicate
samples were collected from each station. However,
due to an accident during shipment, several samples
were destroyed. Only one sample from each sample
was analyzed in the laboratory. Water quality
measurements consisting of depth, temperature,
dissolved oxygen, conductivity, and pH were taken at
every station using a Hydrolab water quality instru-
ment.
Samples were enumerated by species or the lowest
practical taxon with the aid of a Bausch and Lomb
10-70X dissecting microscope. Whole samples were
analyzed at each station due to the low densities
encountered except for those collected at Stations N5
and N12. A 10-ml subsample of a 400-ml sample
concentrate was analyzed at Station N5, while a
stratified count of Station N12 was utilized, whereby
the first 10-ml aliquot of a 100-ml sample concen-
D-1
-------
trate was scanned for all organisms and four subse-
quent 10-ml aliquots were scanned for the more
uncommon organisms. Representatives of each
species were permanently mounted on microscope
slides in CMC-10 and identified at 200- or 500X with
the aid of a Zeiss compound microscope and phase-
contrast illumination. Zooplankton densities (No./m3)
were extrapolated from the subsample volume,
sample concentrate volume, and the volume of water
sampled. The volume of water sampled was esti-
mated from flow velocity and sample time measure-
ments. Diversity was measured using the machine
calculation of the Shannon-Weaver function (EPA
1973).
D.3 Benthic Macroinvertebrates
Benthic samples were collected from nine stations
with a Hess stream sampler (881 cm2). Three replicate
samples were collected from the riffle habitat at each
station. The mesh size on the Hess sampler is 500 /urn,
thereby retaining those benthic organisms classified
as macroinvertebrates. Samples were preserved in
10 percent buffered formalin and returned to the
laboratory for analysis.
Water quality measurements consisting of temper-
ature, dissolved oxygen, pH, and conductivity were
taken at every station. The water quality for the
biological field efforts are discussed in Section 4.1.
Qualitative samples were collected using a D-frame
kick net. Habitats other than riffle areas were sampled
in a standard unit of effort which consisted of two
sweeps ofthe net for a distance which equaled length
of the net pole. The habitats sampled were generally
shorezone vegetated and non-vegetated areas, pools,
submerged aquatic plants, and detritus packs. The
samples were processed on-site by using white
enamel pans and hand-picking techniques. The
organisms were preserved in 10 percent formalin to
await laboratory processing.
Some benthic samples contained large amounts of
detritus and organisms and were subsampled to
expedite organism sorting and identification. Sub-
sampling was done using EA's penumatic rotational
sample splitter (patent pending). Samples were sorted
with the aid of a Wild M-5 dissecting microscope.
Organisms were sorted into major taxonomic cate-
gories and preserved in 70 percent alcohol for later
identification; organisms were identified to the lowest
practical taxon using appropriate keys and references.
Oligochaetes and chironomid larvae were mounted
on microslides prior to identification.
D.4 Fish
Fish collections were made in premeasured sections
at each of the 13 Naugatuck River stations and 7
tributary biological sampling stations. All but one fish
sampling station were 91.4 m long and most of these
were one-half riffle and one-half pool habitat (Table
D-1). Stations M1 and N4 primarily contained pool
habitat.
Table D-1. Dimensions (m) of Pool and Riffle Habitat at
Each Sampling Station
Station
BP1
BP2
GS1
SB1
M1
M2
M5
N1
N2
N3
N4
N4A
N5
N6
N7
N8
N9
N10
N11
N12
Pool
Length
45.7
45.7
0
54.9
73.2
45.7
45.7
45.7
45.7
45.7
75.3
45.7
45.7
61.0
45.7
45.7
45.7
45.7
45.7
45.7
Riffle
Length
45.7
45.7
91.4
36.6
18.3
45.7
45.7
45.7
45.7
45.7
16.2
36.6
45.7
30.5
45.7
45.7
45.7
45.7
45.7
45.7
Mean Width
Entire Section
3.6
6.4
4.6"
5.2
10.4
6.4
13.4
8.2
19.5
14.9
18.6
14.6"
21.9
32.0
38.1
28.6
38.7
39.6
29.6
19.8"
"Estimated.
bStream bissected by island; only sampled one channel.
Most fish collections were made with a Coffelt VVP-
2C electroshocker operated either from a towed pram
or from the stream bank. Pulsed direct current was
generated through two hand-held positive electrodes.
Each section of stream was fished from bank-to-bank
in the upstream direction. Captured fishes were held
in buckets of stream water until an entire section was
completed, and then they were identified and count-
ed. Only those fish of questionable identify and
requiring further examination were preserved and
returned to the laboratory. Remaining fishes were
either released alive or properly disposed of if dead.
D.5 Data Analysis
At tributary Stations BP1, BP2, GS1, and SB1, the
habitat was small (average stream width of 5.2 m) and
shallow and thus unsuitable for the electrofishing
system. These sites were sampled by placing a 1.2 m
by 3.4 m, 0.32-cm mesh seine in position and
"kicking" the rocks and habitat above the seine to
chase fish down into the seine. This was done
throughout each 91.4-m section such that all avail-
able habitat was sampled.
In conjunction with fish sampling, stream widths
were measured at four approximately equidistant
0-2
-------
points through the section. This was used in the
computation of number of fish per 93 m2.
Community response was examined using both an
index of diversity and a community loss index. The
Shannon-Wiener diversity index (Shannon and
Weaver, 1963) is based on information theory, and
incorporates both the number of taxa present (rich-
ness) and the distribution of individuals among taxa
(evenness). Diversity and associated parameters of
evenness and redundancy were calculated. The
community loss index (Courtemarch 1982) which is
based on the presence or absence of species empha-
sizes taxonomic differences between the reference
station and the station of comparison. In this index,
rarer species are given equal weight to the more
abundant taxa. Therefore, an effect is measured as
the elimination or replacement of entire species
populations. The formula used to calculate com-
munity loss is:
A-C
(Equation D-1)
B
where
A = number of species found at reference station
B = numberof species found at station of comparison
C = number of species common to both stations
D-3
-------
-------
Appendix E
Onsite Toxicological Data
Table E-1. Routine Chemistry Data for Effluent Dilution Toxicty Tests, Naugatuck River, Waterbury, Connecticut
Sample
Torrington
POTW
Waterbury
POTW
Naugatuck
POTW
Steele Brook
Mad River
Percent
Effluent
(v/v)
100
30
10
3
1
100
30
10
3
1
Dilution
Water3
100
30
10
3
1
100
30
10
3
1
Dilution
Water8
100
30
10
3
1
Dilution
Water'
Initial DO
(mg/L)
pH Range
6.9-7.3
7.2-7.3
7.3-7.5
7.4-7.5
7.5
7.0-7.2
7.0-7.3
7.1-7.4
7.2-7.5
7.2-7.6
7.2-7.7
7.0-7.1
7.3
7.3-7.4
7.4-7.5
7.4-7.6
7.0-7.2
7.2-7.3
7.3-7.5
7.4-7.5
7.4-7.6
7.5-7.6
7.1-7.3
7.2-7.4
7.3-7.4
7.4-7.5
7.4-7.7
7.1-7.7
X
7.9
8.3
8.4
8.4
8.3
7.7
8.2
8.3
8.3
8.2
8.2
7.0
8.2
8.4
8.4
8.3
8.3
8.4
8.4
8.4
8.4
8.4
8.3
8.5
8.6
8.6
8.8
8.4
Range
6.9-9.2
8.1-8.5
8.2-8.5
8.2-8.5
8.1-8.5 .
7.0-8.4
7.8-8.6
8.1-8.6
8.1-8.6
8.1-8.6
7.9-8.5
6.6-7.4
7.9-8.5
8.2-8.5
8.2-8.6
8.1-8.5
8.1-8.4
8.1-8.7
8.0-8.8
8.1-8.7
8.1-8.9
8.1-8.8
7.6-8.8
8.0-8.8
8.2-8.9
8.3-8.9
8.2-9.8
6.8-9.9
Final DO
(mg/L)
X
7.0
6.3
6.5
6.2
6.1
6.2
5.8
6.1
6.0
6.0
6.4
6.7
6.8
7.0
6.9
6.9
6.2
5.2
6.2
5.8
6.2
6.9
6.6
6.2
6.4
6.2
6.5
6.0
Range
6.5-7.8
4.3-7.7
4.3-7.7
2.7-7.6
3.7-7.4
3.9-7.3
2.0-7.3
1.9-7.7
2.2-7.4
3.8-7.2
5.6-7.1
6.4-7.0
6.6-7.0
6.6-7.5
6.4-7.3
6.1-7.6
2.3-7.8
1.5-7.5
1.5-7.8
1.6-7.4
4.2-7.2
6.2-7.5
5.4-7.4
4.7-7.1
4.8-7.2
4.8-6.9
5.2-7.1
4.4-6.8
Conductivity
433
192
123
100
90
518
252
128
95
80
90
1,150
375
190
120
100
382
160
122
100
93
88
253
140
107
95
88
88
°N1 water was used as dilution water for each POTW effluent dilution test.
E-1
-------
Table E-2.
Stations
N2
N3
N4
N4A
N5
N6
N7
N8
N9
N10
N11
N12
Routine Chemistry Data
pH Range
7.5-7.8
7.2-7.6
7.0-7.5
7.4-7.6
7.3-7.9
7.1-7.5
7.1-7.5
7.1 -7.4
7.1 -7.4
7.3-7.6
7.4-8.2
7.1-7.5
for Ambient Station
Initial DO
(mg/L)
X
8.3
8.1
8.1
8.3
8.6
8.3
8.1
8.6
8.2
8.4
8.8
8.0
Toxicity Tests,
Range
7.7-8.8
7.9-8.3
7.5-8.7
8.0-8.7
8.3-9.0
7.6-9.5
7.5-9.2
7.7-9.0
7.4-8.7
7.8-9.8
8.4-9.2
7.6-8.4
Naugatuck
X
7.0
__
6.8
—
--
5.6
5.6
6.3
5.2
6.6
5.0
6.7
River, Waterbury, Connecticut
Final DO
(mg/i)
Range
5.7-8.2
_.
4.9-7.8
—
--
2.8-7.4
2.9-7.2
3.1-7.6
1.4-6.7
6.1-7.1
1.4-7.5
5.7-7.8
Conductivity
(/umhos/cm2)
153
255
285
258
380
308
373
434
386
484
433
440
Table E-3. Hardness, Alkalinity, and Turbidity Measure-
ments for the Ambient Stations, the Two Trib-
utary Samples and the Three POTWs Tested,
Naugatuck River, Waterbury, Connecticut
Table E-5. Final Dissolved Oxygen Measurements for
Ceriodaphnia Mass Balance Test, Run with
Ambient Samples Collected from the Naugatuck
River, Waterbury, Connecticut
Sample
N1
N2
N3
N4
N4A
N5
N6
N7
N8
N9
N10
N11
N12
Steele Brook
Mad River
Torrington POTW
Waterbury POTW
Naugatuck POTW
Hardness
(mg/L)
38
50
59
62
56
73
74
84
88
83
99
99
94
133
114
82
115
392
Alkalinity
(mg/L)
38
42
47
61
43
38
42
45
35
70
66
55
48
61
46
96
151
145
Turbidity
(NTU)
0.85
1.4
1.7
2.3
2.6
2.0
3.0
4.0
4.7
3.4
3.5
2.7
2.3
5.7
6.4
3.7
5.5
5.9
Table E-4. Final Dissolved Oxygen Measurements for
Ceriodaphnia Impact Station Toxicity Tests,
Naugatuck River, Waterbury, Connecticut
Stream Station
N1A
N1B
NIC
N4
N4A
N10
N11
N12
Mean Final DO
(mg/L)
7.5
7.7
7.7
7.5
7.7
7.8
7.7
7.8
Range
7.2-7.9
7.4-7.9
7.4-7.9
7.3-7.9
7.4-7.9
7.5-8.0
7.5-7.9
7.7-7.9
Station
ft umber
N2
N3
N4
N5
N6
N7
Sample Collection
Day
8/23
8/24
8/25
8/26
8/27
8/28
8/29
8/23
8/24
8/25
8/26
8/27
8/28
8/29
8/23
8/24
8/25
8/26
8/27
8/28
8/29
8/23
8/24
8/25
8/26
8/27
8/28
8/29
8/23
8/24
8/25
8/26
8/27
8/28
8/29
8/23
8/24
8/25
Final DO (mg/L)
Range
7.0-8.3
7.0-7.2
7.0
7.0
6.9-7.0
7.2
6.9-7.2
7.1-7.3
6.5-7.2
7.4
6.9-7.8
6.9-7.0
6.8-7.0
7.0-7.4
6.7-6.9
6.8-7.1
7.2-7.3
6.9-7.3
6.8-7.2
7.0-7.2
7.2-7.4
6.4-7.2
7.1-7.7
7.2-7.3
7.1-7.4
7.3
6.8-7.0
7.5
6.2-7.5
7.0-7.4
7.3-7.6
7.0
7.0
7.2
7.0
6.7-7.0
6.7-7.7
7.0-7.2
E-2
-------
Table E-5 (Continued)
N8
N9
N10
8/26
8/27
8/28
8/29
8/23
8/24
8/25
8/26
8/27
8/28
8/29
8/23
8/24
8/25
8/26
8/27
8/28
8/29
8/23
8/24
8/25
8/26
8/27
8/28
8/29
7.0-7.4
7.0
6.9-7.1
7.1-7.4
6.9
7.3
7.5
7.4
7.3
6.9-7.2
7.1-7.4
6.2-6.6
6.5
7.2-7.9
7.0-7.3
7.4-7.3
6.9
7.3
6.6-6.8
7.4
7.4
7.0-7.3
7.2
6.9-7.3
7.3-7.4
E-3
-------
-------
Appendix F
Off site Toxicological Data
Table F-1. Ranges in Water Quality Parameters for Ambient Stations, Tributaries and Effluent Samples, Naugatuck River
Sample or Effluent
Phase 1
Gulf Stream
Torrington POTW
Thomaston POTW
Steele Brook
Great Brook
Mad River
Station N8
Station N9,
Station N10
Phase II
Station N8
Waterbury POTW
Naugatuck POTW
Naugatuck POTW and
N9 mixture
Waterbury POTW and
and N8 mixture
Station N9
Station N10
Conductivity
(^mhos/cm2)
89-310
70-1 ,600
70-3,300
85-480
75-205
40-355
85-450
60-480
40-550
300-500
400-800
700-2,060
300-700
390-590
1 90-480
230-600
pH
6.70-7.96
6.75-7.67
6.68-7.88
6.78-7.78
6.45-7.66
6.80-8.16
6.70-7.57
6.95-7.92
7.15-7.70
6.21-8.30
7.01-8.41
6.81-8.16
7.01-7.93
7.08-7.95
7.03-8.03
7.27-9.04
Alkalinity
(mg/L as CaC03)
22-43
26-172
32-204
21-63
12-49
25-49
22-46
38-76
44-73
31-47
125-172
74-92
53-65
53-77
47-65
47-62
Hardness
(mg/L as CaCO3)
21-69
25-311
25-1,419
26-146
24-78
24-1 23
24-103
28-119
69-106
69-97
66-111
220-337
87-173
83-100
67-100
73-110
F-1
-------
Table F-2. Measured Water Quality Parameters During Offsite Ceriodaphnia Toxicity Tests
Dissolved Oxygen
(mg/L)
Sample or Effluent
Phase 1
Watorbury POTW
Gulf Stream
Torrington POTW
Thomaston POTW
Steels Brook
Great Brook
Mad River
Station N8
Station N9
Test Dates
24Aug-31 Aug
25 Aug-1 Sept
26Aug-2Sept
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
24Aug-31 Aug
25 Aug-1 Sept
26 Aug-2 Sept
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
24Aug-31 Aug
25 Aug-1 Sept
26 Aug-2 Sept
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
24 Aug-3 1 Aug
25 Aug-1 Sept
26 Aug- 2 Sept"
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
24 Aug-3 1 Aug
25 Aug-1 Sept
26 Aug-2 Sept
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
24 Aug-31 Aug
25 Aug-1 Sept
26 Aug-2 Sept
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
24 Aug-31 Aug
25 Aug-1 Sept
26 Aug-2 Sept
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
24 Aug-31 Aug
25 Aug-1 Sept
26 Aug-2 Sept
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
24 Aug-31 Aug
25 Aug-1 Sept
26 Aug-2 Sept
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
Mean
7.6
7.5
7.6
7.7
7.7
7.7
7.8
7.9
7.6
7.5
7.9
7.9
7.9
7.9
7.6
7.6
7.5
7.9
7.9
7.6
7.9
8.0
7.7
7.7
7.9
7.5
7.7
7.9
7.7
7.7
7.6
8.0
7.6
7.5
7.9
7.9
7.8
7.6
8.0
7.7
7.7
7.9
7.9
7.8
7.6
8.1
7.8
7.8
8.0
7.9
7.9
7.8
7.9
7.9
7.7
7.9
8.0
8.0
7.9
7.8
7.9
7.7
7.9
Range
7.0-8.4
6.8-8.4
6.9-8.6
6.9-8.6
7.1-8.8
7.0-8.8
7.2-8.8
7.3-8.6
7.2-8.2
6.6-8.3
7.4-8.2
6.9-8.8
7.5-8.2
7.6-8.1
6.6-8.3
7.1-8.1
6.9-8.1
7.7-8.1
6.9-8.9
6.6-8.5
7.6-8.5
7.3-8.6
7.0-8.1
6.8-8.3
7.6-8.3
6.5-8.7
7.1-8.4
7.6-8.4
6.6-8.3
7.3-8.0
7.0-8.3
7.2-8.8
6.6-8.9
7.1-8.2
7.7-8.5
7.2-8.5
7.4-8.1
7.1-8.2
7.3-8.8
6.9-8.9
7.3-8.2
7.6-8.4
7.4-8.1
7.4-8.1
7.2-8.0
7.6-8.8
6.8-8.8
7.5-8.3
7.6-8.5
7.5-8.3
7.6-8.1
7.5-8.2
7.5-8.2
7.1-8.9
7.3-8.3
7.6-8.3
7.4-8.7
7.6-8.2
7.7-8.2
7.4-8.0
7.0-8.7
7.4-8.3
7.6-8.4
pH
Mean
7.7
7.7
7.8
7.9
7.8
7.9
7.9
7.5
7.4
7.4
7.1
7.2
7.3
7.3
7.4
7.5
7.6
7.2
7.3
7.6
7.2
7.4
7.7
7.6
7.3
7.3
7.7
7.4
7.6
7.9
7.5
7.4
7.4
7.9
7.4
7.5
7.8
7.5
7.5
7.3
7.8
7.3
7.5
7.6
7.4
7.4
7.2
7.6
7.3
7.7
7.6
7.6
7.4
7.2
7.7
7.2
7.5
7.6
7.6
7.4
7.4
7.7
7.1
Range
7.3-8.2
7.6-7.9
7.5-8.0
7.5-8.1
7.5-8.1
7.6-8.1
7.6-8.1
6.8-8.2
7.2-7.7
7.2-7.5
6.9-7.3
7.0-7.4
7.1-7.4
6.8-7.6
6.8-7.8
7.4-7.8
7.4-7.8
6.9-7.6
7.0-7.7
7.4-7.8
6.8-7.5
6.8-7.8
7.4-8.1
7.3-8.0
7.0-7.9
7.2-7.8
7.5-7.9
6.9-7.8
7.0-8.1
7.4-8.3
7.3-7.7
6.9-7.7
7.1-8.0
7.5-8.2
6.9-7.8
7.0-7.8
7.4-8.0
6.8-7.8
7.0-7.7
6.9-7.5
7.5-7.9
6.9-7.7
6.9-7.8
7.3-7.9
7.3-7.7
6.9-7.7
6.9-7.4
7.5-7.9
6.8-7.6
6.9-8.3
7.3-7.9
7.1-7.8
7.0-7.7
7.0-7.4
7.4-7.9
6.6-7.6
7.0-7.7 .
7.3-7.8
7.5-7.7
7.0-7.6
7.2-7.6
7.5-7.9
6.7-7.4
Temperature (C)
Mean
24.3
23.9
23.8
23.9
23.8
23.8
23.7
24.2
24.2
24.5
23.8
24.9
23.9
23.4
23.9
23.8
24.3
23.7
24.5
23.7
22.6
23.9
23.7
24.1
23.7
25.1
23.7
22.8
23.6
23.7
24.1
23.5
25.1
24.0
22.9
23.5
23.8
24.2
23.6
24.8
24.1
23.1
23.9
23.7
23.8
23.4
24.8
24.1
22.8
23.7
23.7
23.9^
23.7
24.4
23.9
23.0
23.7
23.4
23.9
23.4
24.5
23.6
23.4
Range
23.0-25.7
22.5-24.9
24.5-22.4
22.2-24.9
22.1-25.0
22.1-24.7
19.8-24.7
23.6-25.0
23.4-25.4
23.7-25.0
22.8-24.8
23.0-27.6
22.6-25.0
20.0-24.4
22.9-24.7
23.0-25.1
23.4-24.7
23.0-24.5
22.3-27.7
22.8-25.1
19.5-24.3
22.6-24.9
23.0-25.0
23.5-24.6
22.6-24.5
22.4-28.3
22.8-25.1
20.0-24.3
22.2-24.7
22.7-24.9
23.4-24.5
22.2-24.6
22.4-28.1
22.8-25.7
18.0-24.3
22.0-25.0
22.8-25.0
23.5-24.5
22.2-24.4
22.4-27.7
22.8-25.8
20.0-24.3
23.0-25.0
22.6-24.8
23.4-24.2
22.2-24.4
22.3-28.0
22.5-25.7
20.0-24.4
22.5-24.7
22T6-24.8
23.3-24.5
23.5-24.0
22.1-27.2
22.7-24.8
20.1-24.4
22.3-24.9
22.4-24.2
23.4-24.2
22.8-23.9
22.9-27.1
22.8-24.4
22.2-24.4
F-2
-------
Table F-2. (Continued)
Station N10
Phase 11
Station N8
Waterbury POTW
Naugatuck POTW
Naugatuck POTW and
N9 Mixture
Waterbury POTW and
and N8 Mixture
Station N9
Station N10
24Aug-31 Aug
25 Aug-1 Sept
26 Aug-2 Sept
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
31 Aug-7 Sept
1 Sept-8 Sept
2 Sept-9 Sept
3 Sept-IOSept
4 Sept-1 1 Sept
5 Sept-1 2 Sept
6 Sept-1 3 Sept
31 Aug-7 Sept
1 Sept-8 Sept
2 Sept-9 Sept
3 Sept-1 0 Sept
4 Sept-1 1 Sept
5 Sept-1 2 Sept
6 Sept-1 3 Sept
24 Aug-31 Aug
25 Aug-1 Sept
26 Aug-2 Sept
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
24 Aug-31 Aug
25 Aug-1 Sept
26 Aug-2 Sept
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
24 Aug-31 Aug
25 Aug-1 Sept
26 Aug-2 Sept
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
24 Aug-31 Aug
25 Aug-1 Sept
26 Aug-2 Sept
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
24 Aug-31 Aug
25 Aug-1 Sept
26 Aug-2 Sept
27 Aug-3 Sept
28 Aug-4 Sept
29 Aug-5 Sept
30 Aug-6 Sept
7.9
7.6
7.7
7.9
7.9
7.7
7.9
7.8
8.0
7.9
8.0
7.8
8.1
7.7
7.7
8.0
7.9
7.9
7.7
8.1
7.8
7.7
7.9
7.9
8.0
7.4
8.0
7.8
7.7
7.9
7.9
7.9
7.9
8.0
7.8
7.7
8.0
7.9
7.9
7.7
8.0
7.8
7.6
7.8
7.8
7.9
7.6
7.9
7,7
7.7
7.9
7.8
7.8
7.7
7.9
7.6
7.5-8.2
7.5-7.6
7.7-7.8
7.6-8.1
7.0-8.8
7.3-8.3
7.4-8.4
7.5-8.0
7.7-8.5
7.1-8.3
7.8-8.6
7.5-8.2
7.6-8.6
7.2-8.2
7.4-8.0
7.6-8.3
7.4-8.3
7.2-8.6
7.0-8.3
7.3-8.6
7.4-8.2
7.4-8.0
7.7-8.3
7.4-8.2
7.5-8.7
7.4-8.7
7.7-8.5
7.4-8.4
7.4-7.9
7.7-8.4
7.6-8.2
7.5-8.7
7.2-8.3
7.6-8.6
7.4-8.3
7.4-7.9
7.7-8.4
7.5-8.2
7.4-8.9
7.4-8.2
7.7-8.5
7.5-8.4
7.5-7.9
7.7-8.0
7.6-8.0
7.4-8.5
6.9-8.3
7.5-8.5
7.3-8.1
7.6-7.9
7.7-8.3
7.6-8.0
7.3-8.6
7.3-8.4
7.7-8.4
7.3-8.0
7.5
7.7
7.6
7.5
7.5
7.8
7.2
7.8
7.5
7.5
7.3
7.4
7.6
7.4
7.5
7.7
7.6
7.4
7.7
7.6
7.5
7.5
7.7
7.6
7.5
7.7
7.7
7.6
7.5
7.7
7.8
7.6
7.7
7.7
7.6
7.5
7.7
7.8
7.5
7.8
7.6
7.6
7.6
7.7
7.9
7.7
7.8
7.8
7.6
7.7
7.9
8.5
7.2
8.4
8.4
7.7
7.CT-7.9
7.6-7.7
7.5-7.6
7.1-7.7
7.4-7.5
7.6-8.0
6.9-7.5
7.2-8.9
7.1-7.8
6.9-8.1
6.8-8.0
7.2-7.8
7.1-7.8
7.2-7.5
6.9-8.1
7.5-7.9
7.1-8.1
7.0-7.7
7.4-8.1
7.3-7.9
7.0-7.7
6.8-7.9
7.5-7.8
7.2-8.1
7.1-8.0'
7.5-8.0
7.4-7.9
7.1-7.9
6.9-8.1
7.6-7.9
7.4-8.3
7.1-8.1
7.6-8.0
7.4-7.9
7.1-7.9
7.0-8.1
7.5-7.9
7.6-8.3
7.1-8.0
7.6-8.1
7.6-7.9
7.1-7.9
7.1-8.0
7.6-7.8
7.7-8.1
7.5-8.1
7.6-8.0
7.7-7.9
7.2-7.9
7.3-8.1
7.8-7.9
8.4-8.7
7.3-8.2
8.2-8.6
8.2-8.6
7.3-7.9
23.7
23.4
24.0
23.4
24.6
23.7
23.3
23.6
23.6
23.9
23.2
24.3
23.0
24.4
23.4
23.3
24.1
23.0
24.2
22.9
24.2
23.5
23.3
24.3
23.0
23.8
23.0
24.4
23.3
23.3
25.0
23.1
23.8
22.7
24.5
23.6
23.2
24.7
23.1
24.3
22.7
24.6
23.6
23.4
23.2
23.4
24.1 •
22.9
24.6
23.5
23.3
23.8
23.5
24.1
22.7
24.7
22.6-24.6
22.5-24.3
23.8-24.2
22.7-23.8
23.0-27.3
22.8-24.6
22.2-24.3
22.4-24.3
22.6-24.2
23.3-26.0
22.6-23.6
23.0-25.2
20.9-24.2
23.5-25.9
22.4-24.0
22.8-23.8
23.5-26.0
22.7-23.4
22.6-25.7
21.1-24.2
23.2-25.9
22.4-24.0
22.8-23.8
23.2-26.0
22.5-23.4
22.5-25.2
22.3-24.0
23.0-26.0
22.8-23.7
23.0-23.7
23.5-29.0
22.6-23.5
22.3-25.7
20.8-24.0
27.1-26.1
23.3-24.0
22.6-23.6
23.4-28.0
22.8-23.2
22.9-25.8
20.9-24.0
23.2-26.4
23.4-24.0
23.1-23.8
22.0-23.9
23.3-23.5
22.8-25.5
21.2-23.8
23.4-26.3
22.8-24.0
23.1-23.1
23.4-24.0
23.4-23.6
22.7-25.7
21.1-23.5
23.5-26.4
F-3
-------
Table F-3. Results of Preliminary Methodological Variability Tests With Ceriodaphnia and Waterbury POTW Effluent
Dilution Tests
Sample Test Mean Number 95%
or . Test Concentration of Young Confidence Percent
EffHiont Dates Percent (v/v) per Female Interval Survival
Waterbury POTW
Test 1
Test2
Tost 3
Test 4
TestB
Test6
Test?
22-29 Aug Dilution water
1
3
10
30
100
22-29 Aug Dilution water
1
3
10
30
100
22-29 Aug Dilution water
1
3
10
30
100
22-29 Aug Dilution water
1
3
10
30
100
22-29 Aug Dilution water
1
3
10
30
100
22-29 Aug Dilution water
1
3
10
30
100
22-29 Aug Dilution water
1
3
10
30
100
13.1
13.8
13.2
11.0
3.7s
a
11.6
13.2
14.1
11.5
1.3"
a
12.8
14.2
13.2
11.7
a
--
11.6
13.1
15.2"
12.9
a
--
13.4
12.6
11.8
12.0
a
a
12.5
11.7
12.2
11.2
a
a
12.4
11.5
14.0
12.5
a
—
10.0-16.2
11.3-16.3
9.0-17.4
7.5-14.5
0-11.2
--
9.5-13.8
10.5-15.9
11.5-16.7
8.7-14.3
0-2.6
--
11.5-14.2
12.0-16.4
11.9-14.5
9.6-13.8
--
--
9.9-13.3
11.5-14.8
13.6-16.8
11.0-14.9
.. .
--
12.0-14.8
11.9-13.3
10.6-13.0
10.4-13.6
--
--
10.1-14.9
9.9-13.6
9.3-15.1
9.7-12.6
--
--
10.4-14.4
9.9-13.1
12.4-15.6
11.2-13.8
—
"~
90
90
90
40
20"
0"
80
90
80
70
10"
0"
80
100
70
40
Oa
0°
100
90
90
30
0"
0"
100
100
100
30
0"
Oa
80
90
80
20
0"
0'
90
80
100
70
10"
0"
"Significantly different from dilution water (P < 0.05)
Table F-4. Summary of Preliminary Methodological Variability Tests
Effluent
Waterbury POTW
Phase Test No.
Preliminary*1 1
2
3
4
5
6
7
Test Dates
22-29 Aug
22-29 Aug
22-29 Aug
22-29 Aug
22-29 Aug
22-29 Aug
22-29 Aug
AEC2
Percent Effluent
17.3
17.3
17.3
17.3
17.3
17.3
17.3
'Preliminary testing just prior to start of offsite tests. „.«__, _, ,_ , .^,u ^
*AEC(Aceptable Effluent Concentration) isthe geometric mean of the No Observed Effect Concentration (NOEC) and the Lowest Observed
Effect Concentration (LOEC).
F-4
-------
Appendix G
Biological Data
Table G-1.
Abundance (units/mm2) and Diversity of Periphytic Algae on Natural Substrates in the Naugatuck River, August
1983
Taxa
BACILLARIOPHYTA
(Diatoms)
Achnanthes
Amphipleura
Cocconeis
Cyclotella
Cymbella
Denticula
Fragilaria
Comphonema
Melosira
Navicula
Nitzschia
Pinnularia
Rhoicosphenia
Surirella
Synedra
Unidentified
pennates
Total Bacillariophyta
CHLOROPHYTA
(Green Algae)
A nkistrodesmus
Chlamydomonas
Cladophora
Coelastrum
Cosmarium
Dictyosphaerium
Hydrodictyon
Micractinium
Oedogonium
Oocystis
Pediastrum
Quadrigula
Scenedesmus
Selenastrum
Sorastrum
Sphaerocystis
Staurastrum
Stigeoclonium
Tetraedron
Tetrastrum
Unidentified coccoid
forms
Unidentified
naviculoid forms
Total Chlorophyta
N1
3,219
42
84
42
460
0
84
209
84
2,257
585
0
0
0
42
0
7,108
42
0
0
0
84
836
0
42
209
376
502
0
836
42
0
0
42
0
0
0
460
0
3,471
N2
794
0
0
0
84
0
543
84
543
1,714
3,010
0
0
0
125
0
6.897
460
0
293
0
42
0
0
0
418
0
0
0
8,067
669
0
334
0
11,788
0
167
3,302
0
25,540
N3
3,135
0
0
0
209
209
7,315
0
627
5,643
1 1 ,077
0
0
0
209
0
28,424
209
0
2,299
0
0
0
0
0
0
0
0
836
14,212
1,463
0
0
0
5,016
0
0
2,926
0
26,961
N4
4,807
0
0
0
0
0
2.299
418
2,299
5,016
10,659
0
418
0
0
0
25,916
1,881
0
0
5,016
0
0
0
0
1,672
0
3,762
0
5,643
0
0
0
0
2,508
0
0
8,360
0
28,842
N4A
794
0
0
84
42
0
1,588
84
836
711
1,505
0
0
42
209
0
5,895
42
0
0
669
42
•o
0
0
0
167
920
334
7,775
42
0
0
0
6,855
42
0
1,338
0
18,226
N5
502
0
0
84
0
167
1,338
125
1,547
669
1,170
0
0
42
0
0
5,644
42
167
0
0
42
334
0
42
794
167
3,804
0
3,428
0
752
0
0
1,839
125
0
1,505
0
13,041
N6
314
0
0
104
0
0
104
• 104
0
209
2,194
104
0
0
0
0
3,133
0
104
0
0
104
0
0
0
0
104
0
0
5,748
0
0
0
0
1 0,346
0
0
39,814
1,358
57,578
N7
418
0
0
0
0
0
522
0
0
836
8,360
732
0
104
0
0
10,972
0
0
0
0
104
0
0
0
0
1,045
836
0
1 4,839
0
0
0
0
9,614
0
0
6,479
0
32,917
N8
732
0
0
0
104
0
0
0
0
209
7,210
0
0
0
0
0
8,255
104
0
0
0
418
0
0
0
0
418
0
0
7,942
0
0
0
0
58,206
0
0
21,318
209
88,615
N9
836
0
0
0
0
0
0
209
0
1,672
6,061
104
0
0
0
0
8,882
104
209
0
0
0
0
0
0
0
209
0
0
5,748
0
0
0
0
42,845
0
0
8,256
209
57,580
N10
42
0
0
0
0
0
0
0
0
376
1,463
0
0
0
0
84
1,965
84
0
0
0
0
167
0
0
0
251
0
0
1,797
0
0
0
0
27,254
0
0'
2,132
0
31,685
N11
376
0
0
0
0
0
0
0
0
2,633
1,756
42
0
0
0
0
4,807
0
0
0
0
84
0
0
0
0
167
0
0
4,347
0
0
0
0
15,550
42
0
2,048
a
22,238
N12
209
0
0
0
0
0
209
0
0
0
2,926
0
0
0
0
O
3,344
209
0
0
0
209
0
418
0
0
1,672
0
0
6,688
0
0
0
0
11,077
0
0
23,408
61,655
105,336
CHRYSOPHYTA
(Yellow-green Algae)
Characiopsis
0 1,547
G-1
-------
Table G-1. (Continued)
CYANOPHYTA
(Blue-green Algae)
Aphanocapsa
Chroococcus
Lyngbya
Merismopedia
Oscillatoria
Phormidium
Unidentified coccoid
forms
Total Cyanophyta
836 0
1,714 334
1,965 1,463
334 0
0 794
836 4,138
0 1,254
0
0
0
0
0
2,508
0
0
0
1,672
0
7,106
627
627
0
0
3,010
0
543
878
3,177
0
167
1,087
0
251
334
167
0
0
0
0
0
627
0
0
0
209
0
0
522
0
0
0
0
0
0
4,076
0
0
0
836
0
418
418
418
0
0
376
0
0
251
0
0
669
125
0
167
418
334
0
0
0
0
0
6,688
627
5,685 7,983 2,508 10,032 7,608 2,006 627 731 4,076 2,090 627 1,713 7,315
EUGLENOPHYTA
(Euglenoids)
Eugfena
Trachelomonas
TOTAL PERIPHYTON
DENSITY _
Taxa Diversity ( d )
Taxa Equitability (e)
Total Taxa Identified
0
0
1 6,264
3.78
0.72
27
0 0
0 0
41,967 57,893
3.42 3.20
0.64 0.82
24 16
0
0
64,790
3.72
1.06
18
42
42
31,813
3.45
0.58
27
0
0
20,691
3.85
0.77
27
0
0
61,338
1.70
0.28
15
0 0
0 0
44,620100,946
2.59 1.87
0.59 0.40
14 12
0
0
68,552
1.95
0.32
16
0
0
34,277
1.27
0.25
12
0
0
28,758
2.27
0.43
15
0
0
115,995
2.11
0.44
13
Table G-2. Abundance (units/mm2) and Diversity of Periphytic Alga* on Natural Substrates in Gulf Stream, Steele Brook, Beaver
Pond Brook, and Mad River, August 1983
Sampling Station
Taxa
BACILLARIOPHYTA (Diatoms)
Achnanlhes
Anomoeoneis
Asterlonella
Colonel's
Cyclotella
Cymbella
Eunot/a
Fragilaria
Frustulia
Gomphonema
Molosira
Navicula
Neidium
Nitzschia
Plnnularia
Surirella
Synedra
Tabellaria
Unidentified pennates
Total Bacillariophyta
CHLOROPHYf A (Green Algae)
A nkistrodesmus
Cosmarium
Dictyosphaerium
Oodogon/um
Oocystfs
Pediastrum
Scenedesmus
Setenastrum
Staurastrum
Stigeoclonium
Unidentified coccoid forms
Unidentified naviculoid forms
Total Chlorophyta
GS1
585
0
0
42
0
84
0
42
0
0
0
293
0
836
0
0
0
0
0
1,882
0
0
0
0
293
0
543
0
0
3,219
11,370
334
1 5,759
SB1
68,134
0
418
0
209
209
0
1,672
0
836
0
20,691
209
5,225
418
0
209
0
0
98,230
418
0
0
0
21,318
,0
4,389
0
0
6,897
33,649
58,938
125,609
BP1
1 5,048
209
0
0
0
627
0
418
0
17,138
0
1,254
0
1,463
0
0
1,881
418
0
38,456
209
0
0
2,508
0
0
836
209
0
5,016
836
0
9,614
BP2
1,463
0
0
0
0
0
0
1,463
0
4,180
0
522
0
1,463
104
0
314
0
104
9,613
104
0
0
0
0
0
1,568
732
104
0
209
0
2,717
M1
3,135
209
0
0
209
1,672
0
4,807
0
418
1,045
10,659
0
15,257
0
418
836
0
0
38,665
418
209
0
0
209
0
5,016
' 0
0
2,717
418
0
8,987
M2
4,076
0
0
0
0
157
104
104
52
52
52
836
0
679
0
0
157
0
0
6,269
.52
0
418
0
0
157
627
52
0
0
314
0
1,620
M5
5,643
0
6
0
0
0
0
418
0
418
209
0
0
418
0
0
0
0
0
7,106
0
0
0
0
38,874
0
1,254
0
0
5,434
165,318
6,688
217,568
G-2
-------
Table G-2. (Continued)
CYANOPHYTA (Blue-green Algae)
Lyngbya
Oscillatoria
Phormidium
Unidentified coccoid forms
Total Cyanophyta
EUGLENOPHYTA (Euglenoids)
Trachelomonas
TOTAL PER1PHYTON DENSITY
Taxa Diversity fdj
Taxa Equitability ( e )
Total Taxa Identified
418
0
293
167
878
18,519
2.03
0.39
14
1,463
0
75,031
0
76,494
300,333
3.05
0.61
19
19,019
0
3,762
0
22,781
70,851
2.88
0.60
17
3,971
314
3,971
0
8,256
20,586
3.19
0.81
16
836
13,585
5,852
2,508
22,781
70,433
3.38
0.71
21
366
626
52
1,045
2,090
9,979
3.12
0.61
20
0
0
0
0
0
209
224,883
1.29
0.27
11
Note: StationGSI in Gulf Stream, Station SB1 inSteele Brook, Stations BP1 andBP2inBeaverPondBrook,andStationsM1 M2 andM5
in Mad River.
Table G-3. Crustacean Zooplankton Species Collected from
the Naugatuck River, 25-27 August 1983
Cladocera
Sididae
Diaphanosoma brachyurum (Lievan) 1848
Daphnidae
Ceriodaphnia pulchella Sars 1862
Ceriodaphnia reticulata (Jurine) 1820
Daphnia ambigua Scourfield 1947
Daphnia catawba Coker 1926
Daphnia parvula Fordyce 1901
Scapholeberis aurita (Fischer) 1849
Simocephalus serrulatus (Koch) 1841
Bosminidae
Bosmina longirostris (O. F. Muller) 1785
Macrothricidae
llyocryptus spinifer Herrick 1884
Chydoridae
Acroperus harpae (Baird) 1834
Alona rustica americana Flossner and Frey
1970
Chydorus sphaericus sphaericus
(O^F. Muller) 1785
Leydigia leydigi (Schoedler) 1863
Pleuroxus denticulatus Birge 1879
Copepoda"
Calanoida
Diaptomidae
Diaptomus pygmaeus Pearse 1906
Cyclopoida
Cyclopidae
Cyclops bicuspidatus thomasi S. A. Forbes
1882
Eucyclops agilis (Koch) 1838
Mesocyclops edax (S. A. Forbes) 1891
Paracyclops fimbriatus poppei (Rehberg)
1880
Harpacticoida ,.
"Adults only determined to species; copepodids determined to sub-
order; nauplii determined to order.
G-3
-------
Table G-4. Taxonomic List of Benthic Macroinvertebrates Collected from a Qualitative Sampling Effort in the Naugatuck River
and Tributaries, September 1983
Naugatuck River Stations
Tributary Stations
Platyhelminthes
Turbollaria
Tricladida
Mollusca
Gastropoda
Limnophila
Physidae
Physella
Planorbidae (a. anceps)
Helisoma
Annelida
Oligochaeta
Arthropods
Arachnida
Acarina
Crustacea
Isopoda
Asollidae
Asellus
Amphipoda
Talitradae
Hyalella azteca
Decapoda
Astacidae
Occonectes rusticus
Insects
Ephemeroptera
Caenidae
Caenfs N.
Baetidae
Baetis N.
Calibaetis N,
Centroptilum N,
Heptageniidae
Stanonama
Anisoptera
Aeshnidae
Aeshna N.
Boveria N.
Zygoptera
Calopt arygidae
Calopteryx N.
Coenagrionidae
Argia N.
Enallagma N.
Ischnura N.
Coleptera
Hydrophilidae A.
Laccophilus A.
Laccophilus L
Berosus A.
Barosus L
Tropisternus A.
Haliplidae
Peftodytes A.
Peltodytes N.
Hemiptara
Belosiomaiidae A.
Corixtdaa A.
Corfxfdaa N.
Nepidaa A,
Ranatra A.
Masovaliidae
Mesovelia
1 2 3 4 4A 5 6 7 8 9 10 11 12 GS1 SB1 M1 M2 M5 BP1 BP2
X X
X
X X X X X
X X
xxxxxxx x
X
X
X
XX X
X
X
XX X
X
X
"x x
X
X
x x
X
XX XX
xxx- x xxx
X
X XX
xxx x
X XX
X X
X
x x
X
XX x
X
X X
X X
G-4
-------
Table G-4. (Continued)
Naugatuck River Stations
12344A567891Q 11 12 GS1 SB1
Tributary Stations
M1 M2 M5 BP1 SP2
Megaloptera
Corydalidae
Nigronia
Trichoptera
Hydropsychidae
Hydropsyche I.
Cheumatopsyche I.
Limnephiloidae
Phryganeinae
Oligostomia I.
Dipteria
Simulidae
Simulium I.
Chironomidae p.
Tanypodinae I.
Macropelopiini I.
Procladius I.
Pentaneurini I.
Ablabesmyia I.
Thenemanninnyia grp.
Orthocladiinae I.
Cardociadius I.
Orthocladius I.
Eukieff discoloripes grp.
Chironomini I.
Chronomus I.
Polypedilum I.
Poly, illenoense I.
Poly, tripodura I.
Poly. trip. sco/.
Poly. trip. grp.
Xenochironomus I.
Phaenospectral
Tanytarsini
Cladotanytarsus I.
Orthocladini
Cricotopus
Cricotopus bicinctus
Culicidae P.
Culicidae L.
Anopheles I.
No. of Taxa
X X
X X
X
X
X
X
X
X
X
X "X
X X
X
X
X
X
X X
X X
4 10 12 12 11 2 4 5 5 4 11 5 12 1 1 4 5 2 8 2
Table G-5.
Ranked Abundance Listing for all Macroinvertebrates Collected from Naugatuck River. August 1983
Taxa
Cheumatopsyche I.
Symphitopsyche I.
Tricladida
Leucotrichia pictipes I.
Hydropsychidae I.
Cricot. bicinct. grp. I.
Nais communis
Chironomidae p.
Cladocera
Cricot. tremulus grp. I.
Cricot. cylind. grp. I.
Acarina
Number
1139.416
867.652
709.075
617.168
497.577
426.763
422.243
324.687
309.243
277.792
239.937
234.098
Percent
13.468
10.256
8.381
7.295
5.881
5.044
4.991
3.838
3.655
3.283
2.836
2.767
Cumulative
Percent
13.468
23.723
32.105
39.399
45.281
50.325
55.316
59.154
62.809
66.092
68.928
71.695
G-5
-------
Table G-5. (Continued)
Nematoda
Hyefropsycha I.
Thienemannimyia ser. I.
Cardiocladius 1.
Trlchoptera I.
Bsetis n.
Empldidae I.
/Va/s bretscheri
Rheotanytarsus I.
Polypeditum scalaenum I.
Symphit, morosa 1.
Nemertea
Ancylidae
Trichoptera p,
Polypadilum convictum I.
/Va/s variabilis
Hydroptilidae I.
Eukief. discotoripes grp.
Pristine sima
Emptdfdae p.
Hydropsychidee p.
Antocha I.
Orthocladius I.
tsonychia n.
Bothrio. vejdovskyanum
Nanoc/adius I.
A/a/s a/p/na
Stenonema n.
Leucotrichia sp, a. I.
Pseudocloeon n.
Cr/e. intersect, grp.
Tanytarsus I.
Naispardalis
Polyped. fallaxgrp. I.
Abtabesmyia I.
Enchytraeidae
Tanytarsus coffmani I.
Physelta
Neuraclipsis I.
Psectrocladfus I.
Chaetogaster diastrophus
Branchiobdallida
Hydroptilidaa p.
Aulodrilus limnobius
Limnodrilus udekemianus
Cladotanytarsus I.
Euklef. bavarica grp. I.
Diptera p.
/mm. fw& w/o cop. c/?aef
Crfcot. trifasc. grp. I.
Phaenopsectra I.
Dicrotendipes I.
Parachironomus I.
Hydrozoa
Pristine foreli
Berosus I.
Pagastia I.
Harpacticoida
Corydalus cornutus I.
Ceratopogonidaa I.
Hydroptila I.
Procladius 1.
Oulimnius latiusculus a.
/Va/s simplex
Coenagrfonidae n.
/loo/osoma
Synorthocladius I.
Lumbriculidae
Limnodrilus hoffmeisteri
210.368
186.073
171.948
156.693
155.563
142.192
121.287
96.615
86.633
80.983
69.683
57.630
57.442
56.312
56.123
42.940
41.057
39.173
38.608
38.232
33.523
32.958
30.698
27.308
26.932
23.165
23.165
22.223
21.658
20.905
16.762
14.878
13.937
10.923
10.547
8.852
7.345
6.592
5.650
5.273
4.897
4.897
4.520
4.520
4.520
4.143
3.955
3.578
3.390
3.390
3.390
3.202
3.013
2.825
2.825
2.825
2.825
2.260
2.260
2.260
1.883
1 883
1.695
1.507
1.507
1.507
1.507
1.318
1.318
2.487
2.199
2.032
1.852
1.839
1.681
1.434
1.142
1.024
0.957
0.824
0.681
0.679
0.666
0.663
0.508
0.485
0.463
0.456
0.452
0.396
0.390
0.363
0.323
0.318
0.274
0.274
0.263
0.256
0.247
0.198
0.176
0.165
0.129
0.125
0.105
0.087
0.078
0.067
0.062
0.058
0.058
0.053
0.053
0.053
0.049
0.047
0.042
0.040
0.040
0.040
0.038
0.036
0.033
0.033
0.033
0.033
0.027
0.027
0.027
0.022
0.022
0.020
0.018
0.018
0.018
0.018
0.016
0.016
74.182
76.381
78.414
80.266
82.105
83.785
85.219
86.361
87.385
88.342
89.166
89.847
90.526
91.191
91.855
92.362
92.848
93.311
93.767
94.219
94.615
95.005
95.368
95.690
96.009
96.282
96.556
96.819
97.075
97.322
97.520
97.696
97.861
97.990
98.115
98.219
98.306
98.384
98.451
98.513
98.571
98.629
98.682
98.736
98.789
98.838
98.885
98.927
98.967
99.007
99.047
99.085
99.121
99.154
99.187
99.221
99.254
99.281
99.308
99.334
99.357
99.379
99.399
99.417
99.435
99.452
99.470
99.486
99.501
G-6
-------
Table G-5 (Continued)
Psephenus herricki \.
Chironomus 1.
Dina parva
Eurylophella n.
Oulimnius latiusculus \.
Orconectes
Baetidae n.
Calopteryx n.
Argia n.
Elmidae 1.
Larsia 1.
Dero digitata
Telmat. vejdovskyi
Erpobdella punc. punc.
Ostracoda
Nigronia 1.
Petrophila 1.
Optioservus trivittatus
Chironomidae 1.
Thienemanniella \.
Polypedilum seal. typ. 1.
Paratanytarsus 1.
Rheotanytarsus p.
Tipulidae 1.
Antocha p.
Gasfropocte
Slaving appendiculata
Stephensoniana tandyi
Ephemeroptera n.
Gomphidae n.
Hemiptera n.
Stenelmis a.
Thienemannimyia grp. \.
Brillia 1.
Cricotopus p.
Cryptochironomus \.
Rhabdocoela
Nais „,
Plecoptera n.
Acroneuria n.
G err is n.
Megaloptera \.
Corydalus 1.
Psychomyia 1.
Glossosomatidae p.
Glossosoma \.
Oecetis 1.
Dipt era \.
Microtendipes \.
Parachironomus freq. \.
Limonia 1.
Lymnaeidae
Sphaerium
Turbellaria
Arcteonais lomondi
Aulodrilus pluriseta
Copepoda
Ase/lus
Heptageniidae n.
Heptageniinae n.
Epeorus n.
Serrate/la n.
Tricorythodes n.
Zygoptera n.
Boyeria n.
Paragnetina n.
Phasganophora n.
Rhagovelia a.
Rhagovelia n.
Corixidae n.
1.318
1.318
1.130
1.130
1.130
0.942
0.942
0.942
0.942
0.942
0.942
0.753
0.753
0.753
0.753
0.753
0.753
0.753
0.753
0.753
0.753
0.753-
0.753
0.753
0.753
0.753
0.565
0.565
0.565
0.565
0.565
0.565
0.565
0.565
0.565
0.565
0.377
0.377
0.377
0.377
0.377
0.377
0.377
0.377
0.377
0.377
0.377
0.377
0.377
0.377
0.377
0.377
0.377
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.016
0.016
0.013
0.013
0.013
0.011
0.011
0.011
0.011
0.011
0.011
0.009
0.009
0.009
0.009
0.009
0.009
0.009
0.009
0.009
0.009
0.009
0.009
0.009
0.009
0.009
0.007
0.007
0.007
0.007
0.007
0.007
0.007
0.007
0.007
0.007
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.004
0.002
0.002
0.002
0.002
0.002
O.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
99.517
99.533
99.546
99.559
99.573
99.584
99.595
99.606
99.617
99.628
99.639
99.648
99.657
99.666
99.675
99.684
99.693
99.702
99.711
99.720
99.728
99.737
99.746
99.755
99.764
99.773
99.780
99.786
99.793
99.800
99.806
99.813
99.820
99.826
99.833
99.840
99.844
99.849
99.853
99.858
99.862
99.866
99.871
99.875 .
99.880
99.884
99.889
99.893
99.898
99.902
99.907
99.911
99.915
99.918
99.920
99.922
99T924
99.927
99.929
99.931
99'.933
99.935
99.938
99.940
99.942
99.944
99.947 •
99.949
99.951
99.953
G-7
-------
T«bl« G-5 (Continued)
Polycentropodidae 1.
Polycentropodidae p.
Leucotrichiinaa 1.
Coteoptera p.
Promoreslo \.
Promoresia alegans 1.
Hydrophilidae \.
Ectopria nervosa 1.
Dolfchopodfdae p.
Ephydridae \.
Crlcotopus \.
Heterotrissocladius I.
Perachaetocladius 1.
Polypedilum 1.
Polypedilum ophoides I.
Symposiolladium acutil.
Xenochfr. xenofabfs 1.
Psychodidae p.
Tiputidae p.
Atharix Variegata 1.
Pisfdiidaa
Note; 1 = larva
p = pupa
n = nymph
a = adult
grp = qroup
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.188
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
0.002
99.956
99.958
99.960
99.962
99.964
99.967
99.969
99.971
99.973
99.976
99.978
99.980
99.982
99.984
99.987
99.989
99.991
99.993
99.996
99.998
100.00
Table G-6.
Shannon-Wiener Diversity Indices d and Associated Evenness and Redundancy Value* for th« Benthic
Macroinvertebrates from the Naugatuck River and Tributaries, September 1983.
Station
N1
N2
N3
N4
N4A
N5
N6
N7
N8
N9
N10
N11
N12
GS1
MS
SB1
Diversity"
4.7755
4.01 65
4.6377
3.8117
3.5951
3.1770
3.6509
3.3000
2.6480
3.4889
3.0631
3.2932
2.4384
3.1610
2.8449
3.0076
Evenness
0.7765
0.7547
0.7729
0.6563
0.6437
0.6194
0.7515
0.7295
0.5938
0.7110
0.6771
0.7385
0.5251
0.6807
0.8224
0.8389
Redundancy
0.2260
0.2477
0.2287
0.3445
0.3575
0.3808
0.2522
0.2725
0.4120
0.2921
0.3244
0.2637
0.4768
0.3268
0.1898
0.1 702
Maximum
Diversity
Naugatuck River
6.1498
5.3219
6.0000
5.8074
5.5850
5.1293
4.8580
4.5236
4.4594
4.9069
4.5236
4.4594
4.6439
Tributaries"
4.6439
3.4594
3.5850
Minimum
Diversity
0.0682
0.0515
0.0444
0.0140
0.0192
0.0027
0.0721
0.0336
0.0633
0.0525
0.0208
0.0361
0.01 84
0.1066
0.2221
0.1924
Number of
Species
71
40
64
56
48
35
29
23
22
30
23
22
25
25
11
12
Mean
Density
(No./m2)
5,267
3,759
7,530
22,871
1 3,665
81,149
1,789
3,205
1,503
2,652
5,432
2,806
6,867
972
154
203
Community
Loss
Index"
1.00
0.57
0.81
0.79
1.23
1.71
2.30
2.05
1.76
2.56
2.76
2.29
2.33
7.71
5.50
"Calculated on a logarithmic base 2.
RivertributaryiStations BP1, BP2, M1, M2) were not calculated.
G-8
-------
Table G-7. List of Fish Species and Families Collected from the Naugatuck River and Tributaries, Connecticut
Family
Anguillidae (freshwater eels)
Salmonidae (trouts)
Esocidae (pikes)
Cyprinidae (minnows)
Castostomidae (suckers)
Ictaluridae (bullhead catfishes)
Centrarchidae (sunfishes)
Percidae (perches)
Scientific Name
Anguilla ro strata
Sa/mo trutta
Esox niger
Esoxa. americanus
Notropis cornutus
Notropis hudsonius
Semotilus atromaculatus
Semotilus corpora/is
Rhinichthys cataractae
Rhinichthys atratulus
Exoglossum maxillingua
Notemigonus crysoleucas
Castostomus commersoni
Ictalurus nebulosus
Ictalurus natalis
Lepomis macrochirus
Lepomis gibbosus
Lepomis auritus
Ambloplites rupestris
Micropturus salmoides
Perca flavescens
Etheostoma olmstedi
Common Name
American eel
Brown trout
Chain pickerel
Redfin pickerel
Common shiner
Spottail shiner
Creek chub
Fallfish
Longnose dace
Blacknose dace
Cutlips minnow
Golden shiner
White sucker
Brown bullhead
Yellow bullhead
Bluegill
Pumpkinseed
Redbreast sunfish
Rock bass
Largemouth bass
Yellow perch
Tessellated darter
Table G-8. Analysis of Variance and Tukey's Studentized Range Test Results for Major Benthic Groups, Naugatuck River,
August 1983
Dependent Variable: In count
Source df
Model
Error
Corrected total
12
26
38
Sum of
Squares
Chtronomidae
Mean
Square
23.27
15.47
38.74
1.94
0.60
F Value
PR>F
3.26
0.0057
Tukey's Studentized Range
Station
mean in count
4
(6.3)
12
(6.2)
4A
(5.8)
10
(5.5)
3
(5.2)
9
(5.2)
5
(5.0)
resf
2
(4.9)
11
(4.9)
1
(4.7)
7
(4.3)
6
(4.0)
8
(3.5)
Dependent Variable: In count
Source df
Sum of
Squares
Oligochaeta
Mean
Square
F Value
PR>F
Model
Error
Corrected total
12
26
38
126.81
35.29
162.09
10.57
1.36
7.79
0.0001
Tukey's Studentized Range Test
Station 4 3 5 2 11 4A9 1 6 12 10 7 8
mean in count (6.0) (4.6) (2.9) (2.7) (2.6) (2.3) (1.7) (1.1) (0.7) (0.2) (0) (0) (0)
G-9
-------
Table G-8 (Continued)
Dependant Variable: In count
Source df
Model 12
Error 26
Corrected total 38
Station 1 0 1
mean in count (4.6) (4.5)
Dependent Variable: In count
Source df
Model 12
Error 26
Corrected total 38
Station 5 4A
mean in count (8.4) (6.4)
Ephemeroptera
Sum of Mean
Squares Square F Value PR > F
103.10 8.59 11.05 0.0001
20.21 0.78
123.32
Tukey's Studentized Range Test
4A 11 9 12 5 3 2 8 4
(3.6) (3.6) (1.7) (0.8) (0.7) (0.6) (0.6) (0.6) (0.5)
Trichoptera
Sum of Mean
Squares Square F Value PR>F
226.10 18.84 17.04 0.0001
28.75 1.11
254.86
Tukey's Studentized Range Test
4 1 2 3 6. 7 10 8 9
(5.3) (5.0) (3.9) (3.6) (2.6) (1.3) (1.2) (1.1) (1.0)
7 6
(0.2) (0.2)
12 11
(1.0) (0.4)
Table G-9. Analysis of Variance and Tukey's Studentized Range Test Results for Genera of Hydropsychidae,
August 1983
Dependent Variable: In count
Source df
Model 12
Error 26
Corrected total , 38
Station 5 4A
mean in count (7.2) (4.2)
Dependent Variable: In count
Source df
Model 1 2
Error 26
Corrected total 38
Station 5 4A
mean in count (6.7) (5.3)
Cheumatopsyche spp.
Sum of Mean
Squares Square F Value PR > F
158.45 13.20 13.76 0.0001
24.95 0.96
183.40
Tukey's Studentized Range Test
41 2 3 6 7 10 9 12
(3.9) (3.2) (2.6) (2.3) (1.6) (0.7) (0.7) (0.5) (0.2)
Symphitopsyche spp.
Sum of Mean
Squares Square F Value PR > F
159.34 13.28 13.57 oioOOl
- 25.45 0.98
184.79
Tukey's Studentized Range Test
1 2 4 3 8 7 6 10 9
(4.1) (2.5) (1.9) (1.7) (1.0) (0.8) (0.7) (0.6) (0.5)
Naugatuck River,
8 11
(0.2) (0.2)
12 11
(0.2) (0)
G-10
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Table G-1 0. Analysis of Variance and Tukey's Studentized Range Test Results for Species of Cricotopus. Naugatuck River,
Dependent Variable: In count
Source
Model
Error
Corrected total
Station 1 2
mean in count (5.4)
Dependent Variable: In
Source
Model
Error
Corrected total
Station 1 2
mean in count (4.0)
df
12
26
38
Sum of
Squares
63.05
26.82
89.87
C. bicinctus
Mean
Square F Value
5.25 5.09
1 03
PR>F
0.0003
Tukey's Studentized Range Test
4
(5.1)
count
df
12
26
38
10 11 7
(3.6) (3.4) (3.1)
Sum of
Squares
22.29
18.47
40.76
3 98 6
(2.9) (2.9) (2.7) (2.5)
C. cylindraceus
Mean
Square F Value
1.86 2.61
071
2 4A 1 5
(1.9) (1.7) (1.2) (0.9)
PR>F
0.0195
Tukey's Studentized Range Test
3
(3.7)
495
(3.5) (3.5) (3.3)
2 6 4A 11
(3.2) (2.4). (2,4) (2.4)
C. tremulus
7 10 1 8
(2.2) (2.2) (2.1) (1.3)
Dependent Variable: In count
' Source
Model
Error
Corrected total
Station 4
mean in count (4.6)
df
12
26
38
Sum of
Squares
46.8
25.4
72.2
Mean
Square F Value
3.90 3.99
098
PR>F
0.0015
Tukey's Studentized Flange Test
10
(3.9)
932
(3.8) (3.8) (3.7)
7 12 1 6
(3.0) (2.3) (2.3) (1.9)
5 11 4A 8
(1.9) (1.9) (1.6) (0.8)
* GOVERNMENT PRINTING OFFICE: 1986 - 646116 / 40664
G-11
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