Niagara River Toxics Management Plan, Progress Report and Work Plan, May 1999

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TABLE OF CONTENTS

Page

Executive Summary		ii

PROGRESS REPORT

1.	Introduction		2

2.	The Upstream/Downstream Monitoring Program		3

2.1.	The Statistical Model		4

2.2.	Results from Application of the Statistical Model		4

2.3.	A Perspective on the Yearly Data		6

2.4.	Link to Remedial Activity		6

3.	The Biomonitoring Program		7

3.1.	Caged Mussels		7

3.2.	Juvenile Fish		8

4.	Long Term Trends: Sediment Cores		9

5.	Current Concerns Due to Toxic Chemicals		10

6.	Summary and Conclusions		11

7.	References		13

WORK PLAN

1999 NRTMP Annual Work Plan		W-1

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Niagara River Toxics Management Plan
Progress Report and Work Plan

May 1999
EXECUTIVE SUMMARY

The Niagara River flows 60 kilometres or 37 miles from Lake Erie to Lake Ontario. It serves as a source
for drinking water, fishing grounds, and vacation spots. It generates electricity, and provides
employment to millions of people. Unfortunately, the River is also the recipient of toxic wastes that
pollute its waters and prevent us from fully enjoying its beneficial uses.

Since 1987, the Niagara River has been the focus of attention for four environmental agencies in
Canada and the U.S., referred to here as "The Four Parties". In February 1987, Environment Canada,
the U.S. Environmental Protection Agency Region II, the Ontario Ministry of the Environment and the
New York State Department of Environmental Conservation (the "Four Parties") signed a "Declaration
of Intent" (DOI). The purpose of the DOI is to achieve significant reductions of toxic contaminants in the
Niagara River.

Eighteen "priority toxics" were specifically targeted for reduction, ten of which, because they were
thought to have significant Niagara River sources, were designated for 50% reduction by 1996. The
Niagara RiverToxics Management Plan (NRTMP) is the program designed to achieve these reductions.

In December 1996, the Four Parties signed a "Letter of Support", pledging their continued commitment
to reduce toxic chemical inputs to the Niagara River, to achieve ambient water quality that will protect
human health, aquatic life, and wildlife, and while doing so, improve and protect water quality in Lake
Ontario as well.

The 1999 Progress Report highlights some of the most significant accomplishments since the NRTMP
began, and discusses evidence of continuing concerns due to toxic substance contamination. The 1999
Annual Work Plan describes the actions that the Four Parties and individual agencies are taking or will
take to reduce the amount of toxic chemicals going into the Niagara River from various sources, and to
monitor progress.

NYSDEC/EPA and MOE have previously presented point source daily load data showing greater than
50% reductions in the "priority toxics". NYSDEC and EPA have also presented information on progress
in remediation of hazardous waste sites. This progress report presents corroborative evidence of
progress, to gauge the effectiveness of these actions. The key sources of information used in assessing
progress are:

Changes/trends in the eighteen "priority toxics", determined by using a statistical model and data
from the Upstream/Downstream Program;

Biomonitoring Program data (juvenile fish and caged mussels) which show effectiveness of
remedial programs in reducing chemical inputs to the Niagara River at various sources; and
Sediment core data from Niagara River depositional zone cores in Lake Ontario, presented to
put the trends of the last eleven years into a longer-term context.

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The primary method of assessment is the Upstream/Downstream Program. The program collects bi-
weekly1 water and suspended sediment samples from the head and mouth of the river to measure the
changes in the concentrations and loads of more than 90 chemicals. An advanced statistical model
was used to determine trends for the eighteen "priority toxics" for the period 1986/87 to 1996/97, and
to determine with more certainty, the effectiveness of reductions of chemical loads to the river.

Results show that there have been statistically significant reductions in the concentrations and loads for
most of the eighteen "priority toxics". In many cases the reductions have been greater than 50%. For
some chemicals, the reductions observed are due, in part, to the effectiveness of remedial activities at
Niagara River sources in reducing chemical inputs to the river.

Results from the biomonitoring program were also used to corroborate progress. Juvenile fish,
including spottail shiners and other species, collected at several sites along the Niagara River, revealed
reductions in chlorobenzene and PCB concentrations. Examples presented in the progress report
indicate a reduction of contaminants in caged mussels located near known sources of pollution. These
reductions point to the effectiveness of remedial programs in reducing the inputs of contaminants to the
Niagara River. Juvenile fish collected at upstream locations in two Niagara River tributaries suggest
additional areas for investigation of contaminant sources.

Many toxic pollutants are principally conveyed through waterways attached to suspended sediments.
Dated sediment core samples, collected from the Niagara River depositional zone in Lake Ontario, tell
the history of toxic chemical loadings from the Niagara River to Lake Ontario. The concentrations of
many chemicals in these cores have decreased significantly since the 1960s and 70s. The data show
that suspended sediments flowing through the Niagara River are becoming cleaner and cleaner. The
older contaminated sediments in this depositional area are being buried by the new, cleaner sediments.

Each of the above monitoring programs supports the conclusion that remedial activities have had an
effect in reducing the loads of chemicals to the river. This is the overall goal of the Niagara River
Declaration of Intent and the NRTMP.

Despite the successes to date, more work needs to be done. Several chemicals are still at levels that
exceed the most stringent government water quality criteria in the River. Advisories to limit consumption
of sportfish caught in the Niagara River continue due to toxic contamination. There is evidence of
continuing sources of chemical contamination in the River. Inputs from Lake Erie are also important
for some chemicals. The activities in the 1999 Work Plan reflect the commitment of the Four Parties
to continue to reduce toxic chemical inputs to the River and to monitor the progress. This commitment
includes:

Completing the actions described in prior NRTMP Work Plans;

Ensuring that these actions have been effective;

Implementing additional actions to protect and restore the River; and
Continuing and improving the public reporting of progress.

1 Prior to April 1997, sampling was done on a weekly basis.

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1. INTRODUCTION

In February, 1987, Environment Canada, the U.S. Environmental Protection Agency Region II,
the Ontario Ministry of the Environment and the New York State Department of Environmental
Conservation (the "Four Parties") signed a "Declaration of Intent" (DOI). The purpose of this
Declaration is to achieve significant reductions of toxic contaminants in the Niagara River.
Eighteen "priority toxics" were specifically targeted for reduction (Table 1), ten of which, because
they were thought to have significant Niagara River sources, were designated for 50% reduction
from Canadian and U.S. point and non-point sources by 1996. The Niagara River Toxics
Management Plan (NRTMP) is the program designed to achieve these reductions. The NRTMP
Work Plan identifies activities taken by the Four Parties to remediate sources and to monitor
progress toward protecting the River.

The Four Parties have used a variety of information to assess progress. For example,
NYSDEC/EPA and MOE have presented point source daily load data showing greater than 50%
reductions in the "priority toxics". Reductions in point and non-point source loads for certain
priority toxic chemicals were also indicated by ambient river and biomonitoring data. NYSDEC
and EPA have presented information on progress in remediation of hazardous waste sites. The
ambient river data have yielded definitive trend information after application of an advanced
statistical model developed specifically for this purpose. The trend information is useful for
assessing progress in meeting the 50% reduction goal.

This report presents corroborative evidence of progress. The information presented includes:

1. Changes/trends in the eighteen "priority toxics" determined by using an advanced
statistical model completed by Environment Canada in 1998, and data from the
Upstream/Downstream Program.

2. Biomonitoring Program data (juvenile fish and caged mussels) which can show the
effectiveness of remedial programs in reducing chemical inputs to the Niagara River at
various sources;

3. Sediment core data from Niagara River depositional zone cores in Lake Ontario, to put
the trends of the last eleven years into a longer-term context.

Detailed reports are available elsewhere (see References).

The Four Parties are committed to continuing the reduction of toxic chemical inputs to the
Niagara River, and to assessing the effectiveness of remedial activities at Niagara River sources
in reducing the concentrations of these chemicals in water and biota. At a public meeting in
December 1996, the Four Parties signed a Letter of Support reaffirming their commitment to the
NRTMP.

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In the Letter of Support, the Four Parties agreed to make progress toward the following goal:

To reduce toxic chemical concentrations in the Niagara River by reducing inputs from
sources along the River. The purpose is to achieve ambient water quality that will protect
human health, aquatic life, and wildlife, and while doing so, improve and protect water
quality in Lake Ontario as well.

The 1999 Progress Report also presents information on continuing concerns due to toxic
contamination in the Niagara River, such as exceedances of water quality criteria and
contamination of sportfish. The Work Plan addresses tasks to achieve the Four-Party goal, and
to monitor and report progress.

2. THE UPSTREAM/DOWNSTREAM MONITORING PROGRAM

The Upstream/Downstream Program collects both water and suspended sediment samples from
the head (Fort Erie = FE), and mouth (Niagara-on-the-Lake = NOTL) of the Niagara River. Data
from the Niagara River Upstream/Downstream Program and a statistical model were used to
measure progress toward reducing the inputs of the 18 "priority toxics" to the Niagara River.

This program has measured, on a bi-weekly basis2, the changes in the concentrations and loads
of over 90 chemicals in the water entering and leaving the Niagara River. Using state-of-the-art
sampling and analytical methodologies, the program has been able to detect chemicals at very
low concentrations-much lower than those allowed by the detection limits used in source
monitoring programs.

The Upstream/Downstream Program data set is one of the best, if not the best, monitoring data
set in the Great Lakes Basin. The fact that the program has been designed and operated by
a single agency, Environment Canada, has ensured the consistency of field and laboratory work
and data management. Four Party audits and peer review of the quality of field and laboratory
work are done regularly.

Both seasonal and large, week to week, fluctuations in the N iagara River U pstream/Downstream
data made discernment of a trend in the concentration and load data difficult. Compounding this
difficulty was the fact that the concentrations of many chemicals, particularly organic chemicals,
were so diluted (due to the river's high rate of flow) that they were often below analytical
detection limits. Furthermore detection limits changed during the period of record. A statistical
model was needed to determine trends.

2 Prior to April 1997, sampling was done on a weekly basis.

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2.1. The Statistical Model

A model was developed that could determine reliable trends for the 18 Niagara River "priority
toxics". Model output would also help answer the fundamental question: "Have remedial
programs implemented at Niagara River sources been effective in reducing the loads of these
chemicals to the river?

Detailed discussion of the development and application of the model is presented elsewhere (El-
Shaarawi and Al-lbrahim 1996). For this report, the model was applied to the eleven years of
data for the eighteen "priority toxics" collected between 1986/87 and 1996/97. The same data
were then examined on a year-by-year basis and compared with the modelled eleven-year
trends to determine possible explanations for the changes observed.

2.2. Results from Application of the Statistical Model

Table 2 presents examples of results for the per cent change in the concentrations and loads
of selected chemicals (for which a statistically valid trend could be determined) from the list of
eighteen "priority toxics" between 1986/87 and 1996/97. These examples were chosen because
they illustrate trends exhibited by many of the other eighteen "priority toxics". Data for both the
suspended sediment and water ("dissolved") phases sampled at Fort Erie and Niagara-on-the-
Lake are included.

While the numbers have changed from those presented in the last NRTMP progress report
(based on comparison between 1986/87 and 1995/96), the overall picture has not. The results
show that, with a few exceptions, there have been statistically significant reductions in the
concentrations and loads of these chemicals over the eleven-year period in both phases, at both
FE and NOTL. In many cases, the reductions have been greater than 50%.

In general, decreases in chemical concentrations result in decreases in chemical loads. There
are, however, situations in which a chemical shows an increase in mean concentration, but a
decrease in the load (eg., see benzo(a)pyrene). This is most evident for chemicals on
suspended solids. Loads are dependent on both the chemical concentration and the river flow;
for chemicals on suspended solids, the load is also dependent on the concentration of solids
in the water column. Both the suspended solids concentrations and flow in the Niagara River
decreased substantially over the period from 1986 to 1997 (Niagara River Data Interpretation
Group (NRDIG) 1999). One possible explanation is, therefore, that while the concentration of
the chemical increased, this was offset by the decrease in river flow and suspended solids
concentrations over the same period. The result was a decrease in the overall load of this
chemical.

Figures 1 through 10 are graphs of the actual data and the model output for the concentrations
of dieldrin, PCB, hexachlorobenzene (HCB), mirex and octachlorostyrene (OCS).

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Decreases in the concentrations and loads of chemicals which are detected only at NOTL (eg.,
mirex and OCS) serve as the best examples of the effectiveness of remedial activities in
reducing the inputs of chemicals from river sources. Many of the eighteen "priority toxics",
however, are detected at both FE and NOTL and exhibited significant decreases in
concentrations and loads at both stations.

The question, therefore, was whether the observed decreases at NOTL were due to decreases
in Lake Erie inputs or, to remedial programs implemented at sources along the river.

As the loads from sources along the river are reduced at a faster rate than those from Lake Erie,
the contribution of the FE inputs to what goes out from the Niagara River into Lake Ontario at
NOTL should increase (Williams et al 1992); that is, the ratio FE/NOTL for the
concentrations/loads should increase. Conversely, as the loads coming in from Lake Erie are
reduced at a faster rate than those from Niagara River sources, the contribution of the FE inputs
to what goes out from the River at NOTL should decrease; that is, the ratio FE/NOTL should
decrease. The ratio, therefore, provides a simplified indication of the effectiveness of remedial
programs in controlling the inputs of chemicals to the river.

Table 3 presents estimates of this ratio (expressed as a percent) for 1986/87 and 1996/97 for
the water and suspended sediment concentrations and loads of those chemicals noted in Table
2. It can be seen that for HCB and PCB the ratio has increased, while for dieldrin it has
decreased. Changes in this ratio (FE/NOTL) for both concentrations and loads based on the
annual calculated values from 1986 through 1997 are plotted for dieldrin, HCB, PCB and B(a)P,
in the water phase, in Figures 11 (a) through (d), respectively. The trend in this ratio is evident.
For dieldrin, the ratio is clearly decreasing, indicating that inputs from Lake Erie are being
reduced at a faster rate than inputs from Niagara River sources (Williams et al 1993). Note
however that the inputs of dieldrin along the Niagara River are minor compared to the input at
Fort Erie. Although there have been some variations over time in the ratios for HCB and PCB,
overall the ratios have increased over the eleven-year period. This suggests that remedial
activities at Niagara River sources have probably been the most effective in contributing to the
reduction of the inputs of these chemicals to the river. The ratio for B(a)P has also increased,
although the data since 1991/92 are more difficult to interpret.

Figure 12 shows the recombined whole water loads (i.e., sum of water + suspended sediments)
for PCBs at FE and NOTL, and the differential load (i.e., NOTL - FE, representing the PCB
inputs in the Niagara River). The data corroborate what is stated above for the water phase
using the ratio approach. Up until 1990/91, the decreasing loads at NOTL are due to
decreasing inputs to the river from Lake Erie (note the similarity in the decreasing slopes of the
trend lines). After 1990/91, however, the PCB load measured at NOTL decreases faster than
the load to the river from Lake Erie as measured at FE (note the slope of the NOTL trend line
decreases faster than that for FE). This results in a decrease in the differential load, and is
indicative of successes at Niagara River sources in reducing the inputs of PCBs to the river.

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2.3. A Perspective on the Yearly Data

Figure 13 shows the concentration of octachlorostyrene (OCS) on suspended sediments at
NOTL (measurements of OCS started in 1989). Because this chemical is detected only at NOTL
and not at FE, it can be inferred that the major sources are located along the Niagara River
rather than Lake Erie. Post-1990, OCS exhibits a reduction in concentrations and in both the
number and magnitude of the "spikes". Post-1992, it is generally detected less frequently.
Although the levels of OCS are still less than those observed over the period 1989-1990, there
is some indication that the number and magnitude of the spikes may be increasing. These
observations suggest a reduction of inputs to the river and better control of sources which begin
around 1991. However, following this period, the spikes may reflect an increase in the inputs
on an intermittent basis.

Concentrations of hexachlorobenzene (HCB) at NOTL have consistently been much higherthan
concentrations at FE, indicating significant sources along the Niagara River. Figure 14 shows
the suspended sediment data for hexachlorobenzene (HCB) at NOTL. The data show much the
same pattern as discussed above for OCS. Between 1986 and 1992, there is a reduction in
overall concentrations as well as the number and magnitude of the "spikes". Occasional "spike"
concentrations again occur in 1993 and 1995, but are not evident in the other years. Once
again, these observations suggest a reduction of inputs to the river and better control of sources
beginning around 1990 and 1991. However, continued monitoring will be necessary to establish
whether the spikes in later years reflect a continuing pattern in contaminant concentrations and
inputs.

Figures 15, 16 and 17 show the water concentration data for OCS, HCBD and total
chlorobenzenes, respectively, at NOTL. The data clearly show that something happened to
cause an increase in the water concentrations of these toxic chemicals at the end of 1989 and
extending through 1990/91 similar to that for OCS and HCB on suspended sediments.
Subsequent to this period, the water concentrations are again much lower.

2.4. Link to Remedial Activity

Over the last decade, the U.S. has taken various measures to reduce the pollutant flow of
untreated dry weather discharge (combined sewer overflows and contaminated (groundwater)
from the Falls Street Tunnel to the Niagara River. During the period, 1989 to 1993, remedial
actions and results determined by DEC and EPA included:

• Spring 1989: Implementation of a court order requiring the City of Niagara Falls to pump
dry weather flow in the Falls Street Tunnel to the Niagara Falls Waste Water Treatment
Plant (NFWWTP) up to the capacity of the pumps that convey the flow from the Tunnel
to the treatment plant. Result: Approximately 3 to 4 million gallons a day out of an
average of 13 million gallons a day taken for treatment.

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• 1990-91: Tunnel cracks repaired to reduce groundwater leakage at the intersection of the
tunnel and the NYPA conduits. Result: Source of heaviest contamination to the tunnel
sealed off. Falls Street Tunnel dry weather flow to the River reduced to 2 to 6 million
gallons a day.

• October 1993: Implementation of a new discharge permit for the Niagara Falls Waste
Water Treatment Plant requiring treatment of 100% of the Falls Street Tunnel dry
weather flow. Result: All dry weather flow sent to the NFWWTP for treatment.

The Upstream/Downstream Program data support the conclusion that these actions have
reduced the inputs of a number of chemicals to the Niagara River.

The reasons for continued occurrence of occasional "spikes" post-1992 have not been
determined at this time. Additional monitoring should help establish whether the spikes will
continue.

3. THE BIOMONITORING PROGRAM

Many chemicals can concentrate in the tissues of aquatic organisms and reveal the presence
of contaminants that cannot otherwise be directly detected in water, because of dilution.

3.1. Caged Mussels

Since 1981, MOE has monitored contaminants in caged mussels (Elliptio complanata) at sites
along the Niagara River every two years. The cooperative assistance of the NYSDEC has
enabled mussels to be placed on the U.S. and Canadian sides of the River. The mussel
biomonitoring program has been successful at identifying contaminant sources by providing
information on the presence or absence of contaminants in the tissue of deployed mussels.
Examples presented here, based on information collected in 1995 and prior, document a
reduction of contaminants in caged mussels located in the proximity of known sources of
pollution, especially some of the U.S. priority hazardous waste sites (see U.S. EPA and
NYSDEC, 1998). At some sites, the reductions point to the effectiveness of remedial programs
in reducing the inputs of contaminants to the Niagara River. The results also corroborate those
of the Upstream/Downstream program. Detailed discussion of the 1995 survey results are
presented elsewhere (Richman 1997).

The most recent mussel data, from caged mussel deployments in 1997, suggest that there may
be improvement in some additional areas, and some recurring problems. All these data are
currently being reviewed by the Four Parties.

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~ Hyde Park - Bloody Run Creek

Bloody Run Creek and the nearby seeps which run down the face of the Niagara Gorge were
historically contaminated from the Hyde Park hazardous waste site. Prior to remediation, the
drainage from this site was a major source of dioxin contamination to the Niagara River
(Gradient Corporation 1990). Remediation of Bloody Run Creek was completed by the
Occidental Chemical Corporation (OCC) in 1994.

Figures 18 and 19 show the dioxin and furan concentrations, respectively, in mussel tissue for
the period 1993 to 1995. Concentrations for the last two years were considerably lower than
those reported in 1993. These data suggest that sediment removal actions along Bloody Run
Creek, action to cover and contain contaminated sediment and soil at the mouth of Bloody Run
Creek and on the shoreline of the Niagara River in the vicinity of the creek, together with
remedial actions taken at the site, may have reduced the bioavailability of these contaminants
to aquatic life in this area.

Water levels fluctuate daily to maintain the operation of the hydro generating stations, thereby,
routinely, submerging and then exposing the contaminated shoreline. This site will continue to
be monitored in future surveys since the contaminated sediment covered during the remediation
along the Niagara River shoreline and at the mouth of the creek may continue to be a source.

~ Occidental Durez - Pettit Flume

Figure 20 shows the concentrations of chlorobenzenes in mussels placed at the mouth of the
Pettit Flume, a storm sewer which was contaminated by groundwater from the Durez hazardous
waste site in North Tonawanda. The concentrations of chlorobenzenes typically found in
mussels at the Pettit Flume were considerably lower in 1995 than concentrations found in
previous years suggesting the positive effects of remedial actions carried out by OCC in 1994.

3.2. Juvenile Fish

Juvenile (young-of-the-year)fish, principally spottail shiners (Notropishudsonius), have also been
used in the Biomonitoring Program. These fish have limited home ranges near shore and are
of known age, making them useful indicators of local, recent chemical inputs to the aquatic
ecosystem.

Both MOE and NYSDEC have collected and analyzed indigenous, young-of-the-yearfish. MOE
has collected fish from NOTL since 1975, and from several other Canadian and U.S. locations
at least every other year since the early 1980s. NYSDEC has collected fish from locations on
the U.S. side of the River annually between 1984 and 1987, and about every five years since.
The following results are based on MOE data (Hitchin 1998).

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In 1996, PCB levels in juvenile fish collected at all sites in the Niagara River (with the exception
of common shiners collected at Cayuga Creek) dropped below 200 ng/g for the first time.

Figure 21 shows that the concentrations of PCB in spottail shiners collected at NOTL. have
decreased substantially since the 1970s. In particular, concentrations have continued to decline
over the last four years (1993-1996). In 1995 and 1996, mean PCB concentrations were below
the Great Lakes Water Quality Agreement specific objective of 100 ng/g for the protection of
fish-eating wildlife for the first time.

Chlorobenzene concentrations in young-of-the-year fish collected at several sites throughout
the Niagara River (Cayuga Creek, 102nd Street, Search and Rescue Station, Lewiston,
Queenston, Youngstown and NOTL) in 1996 were considerably less than those measured in
1995. Reasons for the dramatic decline in chlorobenzenes in 1996 are not known at this time.

Decreases in chlorobenzene concentrations in young-of-the-year fish (spottail shiners) are
consistent with the declines seen in the Upstream/Downstream and the caged mussel
concentrations.

In 1996, as part of a supplemental biomonitoring project in Lake Ontario and the Niagara River
(NYSDEC 1998), NYSDEC collected juvenile fish for contaminant monitoring (including PCBs
and organochlorine pesticides) from two tributaries in the upper Niagara River (Scajaquada
Creek in Buffalo and Two-Mile Creek in Tonawanda). In this project, fish were collected from
upstream locations, unaffected by changing lake levels. The stations were chosen based on
the potential for having elevated levels of contamination in fish tissue but (in most cases) which
had not been examined previously. The intent was to determine whether upstream contaminant
sources may be present in significant concentrations, and to indicate areas where further
contaminant trackdown efforts may be required. The mean PCB concentration in samples of
juvenile bluntnose minnow in Scajaquada Creek was the highest of all the tributaries sampled
(approximately 1400 ng/g, wet weight). The sites sampled are not affected by any of the U.S.
Niagara River priority hazardous waste sites. Follow-up investigations were recommended to
determine the source(s) of the contamination.

4. LONG-TERM TRENDS: SEDIMENT CORES

In the fall of 1995, NYSDEC ,USEPA and Environment Canada collected sediment core samples
from the depositional area in Lake Ontario at the mouth of the Niagara River. Analyses of the
cores and data interpretation were done by NYSDEC (NYSDEC 1996). Dated cores from this
area tell the history of toxic chemical loadings to Lake Ontario from the River, because many
toxic pollutants (e.g., pesticides, PCBs) are principally conveyed through waterways attached
to suspended sediments. Every few centimeters along the length of the core were analysed
separately to determine the concentrations of toxic chemicals on deposits from the particular

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time frame represented by that segment. Radioisotope dating was used to determine the
approximate years during which the sediments were deposited. These sediment cores put the
trends of the last ten years into a long-term context.

Results for dioxin (2,3,7,8-TCDD), hexachlorobenzene, benzo(a)pyrene, and mirex are shown
in Figures 22 (a) through (d). The depth from the surface is shown on the left of the graph. The
corresponding approximate time frame of deposition is also shown. These data indicate that the
burden of toxic chemicals associated with suspended sediment coming from the River has
declined significantly. The most dramatic declines occurred between 1960 and 1980, with the
exception of HCB, which shows mixed results from 1970 to the present, and benzo(a)pyrene,
which has exhibited a more steady decline over the period represented in the core. Similar
results were observed for all priority toxic chemicals analysed.

The graphs also show a line entitled "Persaud's LEL (Lowest Effect Level)", [i.e., formally
Ontario's Provincial Sediment Quality Guideline LEL (Persaud et al. 1993)] which is the
concentration at which a contaminant can be expected to begin to affect aquatic organisms.
This set of guidelines is the most complete, and in most cases the most rigorous, for toxic
chemicals in sediment. The sediment concentrations of the priority chemicals in the 1960s and
1970s were above the LELs. However, as the Upstream/Downstream sampling has shown,
suspended sediments flowing through the Niagara River are becoming cleaner and cleaner.
The older contam inated sediments in this depositional area are being buried by the new, cleaner
sediments so that the surface concentrations of all priority chemicals in these cores, with the
exception of DDE and PCB congeners, are now less than the LELs.

5. CURRENT CONCERNS DUE TO TOXIC CHEMICALS

Despite the progress in reducing toxic chemical inputs to the Niagara River, there are continuing
concerns. For example, some toxic chemicals continue to exceed the most stringent
government water quality criteria, and advisories on consumption of sportfish due to toxic
chemical contamination continue. While the following discussion may not necessarily address
all the current concerns, it suggests the need to continue the program to reduce inputs of toxic
chemicals to the River.

Six of the eighteen NRTMP priority toxic chemicals (Table 1) have also been designated as
"Critical Pollutants" in the Lake Ontario Lakewide Management Plan (LaMP). That is, they are
causing, or likely to cause, lake-wide impairments to "beneficial uses" in the lake (Table 4).
Thus, as Niagara River sources of these chemicals continue to be reduced, Lake Ontario will
also benefit.

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New York State and Ontario issue advice regarding consumption of sportfish caught in their
waters. In the Niagara River, New York State has issued advisories on the consumption of
certain species of sport fish, based on contamination by PCBs, mirex and dioxin (NYSDOH
1998). The 1998/1999 New York State advisories for the Niagara River are summarized in
Table 5. These advisories are unchanged from the 1997/1998 advisories.

The Ontario MOE issues advice contained in a biannual "Guide to Eating Sport Fish".
Consumption advice on a total of 18 species offish from two locations on the Niagara River is
included in the guide. The consumption advice is based on health protection guidelines
developed by Health Canada. Table 6 is taken from the 1999/2000 guide (MOE 1999). The
1999 consumption tables show less restrictive consumption advice for Chinook salmon, rainbow
trout and lake trout than the 1997/1998 guide. Elevated concentrations of mercury, PCBs, and
mirex continue to be the major causes of consumption advisories for the sport fish found in the
Niagara River.

The 1996/1997 Upstream/Downstream Monitoring Program (NRDIG 1999) identifies a number
of NRTMP priority toxic chemicals that are still exceeding the most stringent government water
quality criteria in the Niagara River (Table 7). The Upstream/Downstream Monitoring Program
has identified some additional chemicals, for example several polycyclic aromatic hydrocarbon
(PAH) compounds, that are also exceeding the water quality criteria.

The 1996/1997 Upstream/Downstream Monitoring Program has also identified a number of
chemicals for which the loading in 1996/1997 was higher at NOTLthan at FE in the water and/or
suspended solids phase, indicating that Niagara River sources remain. Several of the NRTMP
priority toxic chemicals are among those identified, including all the chemicals in Table 7.
Additional indications of continuing sources to the Niagara River may be found through
contaminant biomonitoring and source trackdown programs. For example, note the discussion
regarding PCB contamination in juvenile fish (pages 8-9).

While Niagara River sources remain, the loadings of some of the chemicals at Fort Erie,
representing the input to the Niagara River from upstream sources, including Lake Erie, are
significant. For example, as illustrated in the last column of Table 7, the loads at FE are greater
than or roughly equivalent to the differential load (i.e. NOTL-FE) for two of the six chemicals
(based on recombined whole water). Thus, while a continued focus on Niagara River sources
is essential, improving the River may also involve actions beyond its boundaries.

6. SUMMARY AND CONCLUSIONS

The Upstream/Downstream Program and the Biomonitoring Program are important,
complementary programs that are key to measuring the success of the NRTMP. The
Upstream/Downstream Program measures the input from Lake Erie, output to Lake Ontario, and

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the difference between the two. It cannot, however, reveal the sources along the river that are
responsible for this difference. This is where the Biomonitoring Program is most effective.

Results from applying a statistical model to the Upstream/Downstream Program data show that,
with a few exceptions, there have been significant decreases in the concentrations and loads
of most of the eighteen "priority toxics" over the eleven-year period between 1986 and 1997.
The decreases in both the concentrations and loads for many of the eighteen chemicals
exceeds 50%. For some of the eighteen chemicals, the reductions are due to the effectiveness
of remedial activities in reducing inputs from Niagara River sources.

This conclusion is corroborated by analysis of the Biomonitoring Program data. For example,
PCB concentrations in spottail shiners collected at NOTL continue to decrease since 1993. In
1995 and 1996, concentrations were below the Great Lakes Water Quality Agreement specific
objective for the protection offish eating wildlife for the first time since the Niagara River young-
of-the-yearfish program began. Also, based on information from 1995 and prior, concentrations
of several chemicals in the tissue of mussels placed adjacent to some known sources of
contamination to the river are the lowest over the period of record.

Concentrations of priority toxic chemicals in cores collected from the depositional zone of the
Niagara River in Lake Ontario have declined significantly. For most chemicals, the most
dramatic declines occurred between 1960 and 1980. Concentrations of these chemicals in the
1960s and 1970s were above the Ontario Provincial Sediment Quality Guideline LEL (lowest
effect level = LEL). However, with the older contaminated sediments in this depositional area
now being buried by cleaner sediments entering the Lake from the river, surface concentrations
of all priority chemicals in these cores, with the exception of DDE and PCB congeners, are now
less than the LELs.

Each set of data corroborates the other. All results lead to the same conclusion: remedial
activities have had an effect in reducing the loads of chemicals to the river and thus, their
concentrations in the river. This is the overall goal of the Niagara River Declaration of Intent
and the NRTMP.

Despite the successes to date, more work needs to be done. For example, several chemicals
still exceed the most stringent government water quality criteria and contaminate sportfish in the
River. There is evidence of continuing sources of some of these chemicals in the River.
Upstream sources are important for a few of the chemicals. The Four Parties will continue to
monitor progress toward reduction of chemical concentrations in the Niagara River, and to
define additional actions necessary to reduce toxic chemical inputs, through the activities
outlined in the 1999 Work Plan.

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7. REFERENCES

El-Shaarawi, A.H., and A.H. Al-lbrahim. 1996. Trend Analysis and Maximum Likelihood
Estimation of Niagara River Data (1986-1994). National Water Research Institute and
McMaster University, Burlington, Ontario.

Gradient Corporation. 1990. Lake Ontario TCDD Bioaccumulation Study, Final Report. U.S.
Environmental Protection Agency, New York State Department of Environmental
Conservation, New York State Department of Health and Occidental Chemical
Corporation.

Hitchin, G. 1998. Contaminants in Niagara River Juvenile Fish -1996. Ontario Ministry of the
Environment, Toronto, Ontario. Summary Report. January 1998.

MOE. 1999. Guide to Eating Ontario Sport Fish, 1999-2000. Ontario Ministry of the
Environment, Toronto, Ontario.

Niagara River Data Interpretation Group (NRDIG). 1999. Joint Evaluation of
Upstream/Downstream Niagara River Monitoring Data 1996-1997. Environment Canada,
Ontario Ministry of the Environment, New York State Department of Environmental
Conservation and the United States Environmental Protection Agency. Draft Final
Report, February 11, 1999.

NYSDEC. 1996. Lake Ontario Sediment Survey: 1995 Sediment Coring Results. New York
State Department of Environmental Conservation, Division of Water, Bureau of
Watershed Assessment and Research, Albany, New York.

NYSDEC. 1998. Contaminants in Young-of-Year Fish from Selected Lake Ontario Tributaries.

New York State Department of Environmental Conservation, Division of Fish, Wildlife
and Marine Resources, Albany, New York.

NYSDOH. 1998. Health Advisories, Chemicals in Sportfish and Game, 1998-1999. New York
State Department of Health. Revised September 1998.

Persaud, D., R. Jaagumagi, and A. Hayton. 1993. Guidelines for the Protection and
Management off Aquatic Sediment Quality in Ontario. Ontario Ministry of the
Environment, Toronto, Ontario.

Richman, L. 1997. Niagara River Mussel Biomonitoring Program, 1995. Surface Water
Section, Environmental Monitoring and Reporting Branch, Ontario Ministry of the
Environment, Toronto, Ontario. Final Report, November 1997.