Niagara Power Project FERC No. 2216

DESCRIBING CONTAMINANT LEVELS IN FISH IN LEWISTON RESERVOIR

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Prepared for: New York Power Authority

Prepared by: The Louis Berger Group, Inc.

August 2005

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The New York Power Authority is in the process of relicensing the Niagara Power Project, located in Lewiston, New York. As part of this process, stakeholders to the relicensing requested a study to describe the contaminant levels in fish in the Lewiston Reservoir. The study objective was to describe the concentration of contaminants, if any, in Lewiston Reservoir fish and to document available information regarding contamination of upper Niagara River fish.

The Lewiston Reservoir has a gross storage capacity of 74,250 acre-feet. The usable storage capacity is 69,500 acre-feet, or 94% of the gross storage capacity. When the reservoir is at maximum water surface elevation, the water depth is approximately 42 feet. At maximum reservoir drawdown, the average water depth of the wetted areas is just over 3 feet. Typically, the reservoir is drawn down during weekdays and refilled at night (although it is not fully refilled each day), with a gradual drawdown through the week to its lowest level at the end of the week. It is fully refilled on Saturday and Sunday.

Study components to meet the objectives included an evaluation of the sediment quality in the Lewiston Reservoir, the water quality in the reservoir and Niagara River, sedimentation processes in the reservoir, and an assessment of the bioavailability of any contaminants to selected Lewiston Reservoir species of fish, to provide a qualitative assessment of potential contaminant levels in these fish. This approach was chosen, in lieu of sampling fish tissue in the reservoir, due to the dynamic nature of the system. Specifically, the constant reservoir filling and water withdrawal during pumping and generation may affect fish residency time. Because residence time and past habitat utilization of fish prior to being pumped into the reservoir is unknown, it is uncertain whether contaminant levels observed in short-term fish sampling would be representative of the longer-term contaminant levels of reservoir fish.

Sediment Quality in Lewiston Reservoir

Sediment quality data are available from samples collected from the upper 6 inches of the sediment column in the Lewiston Reservoir in 1983, 2002, and 2003. Sediments in the reservoir were analyzed for metals, organic compounds, and grain size. On average, the upper sediments consisted of 95% silt and clay with minor fractions of sand and gravel. Contaminant concentrations detected in the sediments were compared to New York State Department of Environmental Conservation (NYSDEC) guidelines for human health bioaccumulation, which relate to an assumed risk associated with estimates of consumption and bioaccumulation of contaminants in fish (NYSDEC 1999a ). In addition, data were compared to probable effects concentrations (PEC) and threshold effects concentrations (TEC), which relate contaminant concentrations in sediment to biological effects on bottom-dwelling aquatic organisms (MacDonald et al. 2000); similar guidelines for aquatic life are available for metals from NYSDEC (1999a).

Contaminants that exceeded these guidelines in one or more samples included arsenic, lead, mercury, polynuclear aromatic hydrocarbons, polychlorinated biphenyls, and mirex. Similar concentrations of these contaminants also were detected in some of the Niagara River samples collected in 2002. A comparison with other published sediment quality data from sediments in the Niagara River, compiled in Environmental Standards, Inc. (ESI) 2005, shows that the contaminant concentrations in the sediments of the Lewiston Reservoir are well within the range of concentrations measured in the sediments of the Niagara River.

Water Quality in Lewiston Reservoir and Niagara River

Water quality studies in the Niagara River have been conducted for more than 20 years by Environment Canada and NYSDEC. Environment Canada has maintained stations in the upper and lower Niagara River at Fort Erie and Niagara-on-the-Lake, respectively. NYSDEC has maintained a station in the lower Niagara River at Fort Niagara. Water quality data also were obtained by the URS Corporation in 2003. Contaminant concentrations in the surface water were compared to NYSDEC standards for survival and propagation of aquatic life and standards for the protection of human health from the consumption of fish (NYSDEC 1999b).

None of the measurements from these studies of organic compounds and heavy metals in the Niagara River since 1997 exceeded the NYSDEC water quality criteria for aquatic life effects, with the exception of iron. Several organic compounds (hexachlorobenzene, octachlorostyrene, dichloro-diphenyl-trichloroethane and metabolites, mirex, chlordane, dieldrin, and polychlorinated biphenyls) in the river exceeded the NYSDEC water quality criteria for human health (consumption of fish). However, heavy metal and organic compound concentrations measured by the URS Corporation in 2003 in the river (at the New York Power Authority river intake structure) and in the Lewiston Reservoir were all below the detection limit with the exception of monomethyl mercury and the organic compound delta-BHC.

Turbidity and suspended sediment data also were compiled. The suspended sediment concentrations are typically highest in the late fall and winter months as a result of storms stirring up sediments in Lake Erie and increasing sediment runoff from the tributaries to the Niagara River.

Sedimentation in Lewiston Reservoir

The net deposition rate in the Lewiston Reservoir was determined by comparing reservoir bottom topography/elevations between surveys conducted in September 1961 and in May 2001. In this 39.7-year period, the average sediment deposition rate for the entire reservoir was approximately 0.29 inches/year. Sediment is not deposited uniformly in the reservoir. The reservoir has areas of deposition and areas of no deposition or minor erosion. The primary depositional areas are located in the central parts of the reservoir. Generally, deposition also does not occur on shallow areas in the northern parts of the reservoir; these areas are exposed at low water levels during drawdown. Erosion of bottom sediment due to the pumping/draining of water in the reservoir appears to be limited to the immediate vicinity of the Lewiston Pump Generating Plant. One of the reasons for the limited erosion in this area is likely the large rock apron that was placed on the reservoir floor in front of the plant during construction.

Waves in the Lewiston Reservoir are generally not expected to generate scour of the bottom sediments. In the shallow areas of the reservoir that are exposed at low water elevations, the wave energy prevents settling sediment particles from permanent deposition. Particles settle in the deeper part of the reservoir. These settled particles are expected to contain chemical concentrations that reflect recent concentrations in suspended matter within the Niagara River. Minor scour, if any, of sediment may only occur in the reservoir within a few yards of the dikes.

Bioavailability of Contaminants

Chemical or contaminant residues in fish are a function of chemical concentrations in the water and sediment in which they live, and the prey they ingest. Fish take up chemicals in the water column via respiration through the gills and dermal contact (Connell 1989, USEPA 2000). Chemicals in prey items are ingested. Chemicals in sediment can be ingested incidentally while the fish is preying on benthic macroinvertebrates such as insect larvae. Particulates, such as suspended sediment in the water column, can also be ingested. Sediment and water column phases are interconnected in an ecosystem through fate and transport processes such as hydrodynamics, diffusion, particle deposition, and resuspension.

The potential source of contaminants in the water column is Niagara River water that is pumped into the reservoir. Resuspension of sediment is likely limited to recent unconsolidated particulate matter that has settled to the reservoir floor, but has not become part of the permanent sediment column. Scour of older sediments from the reservoir floor appears to be very minor. In addition, dissolved contaminants leached from bottom sediments into the water column are expected to be an insignificant source due to the high exchange rate of water in the reservoir. Therefore, it appears that the exposure of contaminants to fish in the Lewiston Reservoir is generally similar to the exposure to contaminants in the upper Niagara River and its tributaries, in areas of lower flow velocity and fine-grained sediment.

Contaminant Levels of Lewiston Reservoir Fish

Contaminant levels in fish living in the reservoir were evaluated using water quality and sediment data collected from the river and the reservoir, probable exposure pathways, existing fish tissue data for the river, and the life histories of the fish that occur in the reservoir. Tissue analyses from fish in the Niagara River detected mercury and organic compounds. Contaminant levels of Lewiston Reservoir fish are expected to be similar to the range of levels exhibited in fish living in fine-grained sediment areas of the upper Niagara River, based on the comparable contaminant levels in the water and in the fine-grained sediment of the reservoir and river. Exposure pathways for fish in the Lewiston Reservoir and Niagara River are also similar in regard to water, sediment, and prey items. Additionally, fish in the reservoir may not be permanent long-term residents of the reservoir.

There are no tissue data available for fish collected from the reservoir. However, based on an evaluation of the available fish tissue data from the river, it is expected that carp, which is a bottom-feeding omnivore, would contain the highest relative concentration of polychlorinated biphenyls and certain pesticides, when compared to other fish species. Other species such as yellow perch, rock bass, and smallmouth bass are expected to contain lower levels than carp, based on existing river tissue data.

Because contaminant levels in fish living in the reservoir are expected to be similar to fish in the upper Niagara River, the current health advisory provided by the New York State Department of Health for consumption of carp caught from the upper Niagara River should also be observed for carp caught from the Lewiston Reservoir. In addition, any future health advisories that may be developed for the upper Niagara River by the Ontario Ministry of the Environment and the New York State Department of Health should be considered applicable to Lewiston Reservoir fish.

ABBREVIATIONS

Agencies

EC Environment Canada

IJC International Joint Commission

NOAA National Oceanic and Atmospheric Administration

NYPA New York Power Authority

NYSDEC New York State Department of Environmental Conservation

NYSDOH New York State Department of Health

OMOE Ontario Ministry of the Environment

USACE United States Army Corps of Engineers

USEPA United States Environmental Protection Agency

USGS United States Geological Survey

Units of Measure

cfs cubic feet per second

cm centimeter

ft/s feet per second

gpm gallons per minute

h hour

kg kilogram

km kilometer

l liter

mg milligram

m/s meters per second

ng nanogram

NTU Nephelometric Turbidity Unit

s second

μg microgram

USLSD U.S. Lake Survey Datum 1935

Environmental

LEL lowest effects level

PAH polynuclear aromatic hydrocarbon

PEC probable effects concentration

PCB polychlorinated biphenyl

RWW recombined whole water

SEL severe effects level

SVOC semivolatile organic compound

TEC threshold effects concentration

TOC total organic carbon

TVS total volatile solids

VOC volatile organic compound

Miscellaneous

LPGP Lewiston Pump Generating Plant

NPP Niagara Power Project

NRTMP Niagara River Toxics Management Plan

PID Photoionization Detector

RIBS Rotating Intensive Basin Study

RMNPP Robert Moses Niagara Power Plant

1.0 INTRODUCTION

The New York Power Authority (NYPA) is engaged in the relicensing of the Niagara Power Project (NPP), located in Lewiston, Niagara County, New York. The present operating license of the plant expires in August 2007. As part of its preparation for the relicensing of the Project, NYPA is developing information related to the ecological, engineering, recreational, cultural, and socioeconomic aspects of the Project.

1.1 Objective

The objective of the study was to describe the concentration of contaminants, if any, in Lewiston Reservoir fish and to document available information on contamination of upper Niagara River fish.

1.2 Project Description

The 1,880-MW (firm capacity) NPP is one of the largest non-federal hydroelectric facilities in North America. The NPP was licensed to the Power Authority of the State of New York (now NYPA) in 1957. Construction of the Project began in 1958, and electricity was first produced in 1961.

1.2.1 Project Components

The NPP has several components that are described below and shown in Figure 1.2.1-1.

NYPA Intakes: Two adjacent intakes are located approximately 2.6 miles upstream of Niagara Falls, and have a total withdrawal capacity of 110,000 cfs.

Water Intake Conduits: Intake water bypasses Niagara Falls through two conduits with a length of 4.3 miles. Travel time is less than 30 minutes at an average velocity of approximately 14 feet per second (ft/s) (Norm Stessing, NYPA, pers. comm., 10/3/03). The conduits decrease in elevation by 11 feet between the intake and the forebay. The conduits have a width of 46 feet and a maximum height of 66 feet. The floor of the conduits is flat, and the ceiling is arched. The conduits are closed structures, built with reinforced concrete, and the wall and floor thickness is 2.5 feet. The total capacity of each conduit is 55,000 cfs.

Forebay: The forebay has an area of 71 acres and a capacity of 1.8 billion gallons. It is approximately 4,200 feet long, 500 feet wide, and 110 feet deep. The depth of water in the forebay varies between 35 and 63 feet, depending on operating conditions.

Robert Moses Niagara Power Plant: The Robert Moses Niagara Power Plant (RMNPP) is NYPA’s main generating plant at the NPP with a head of approximately 300 feet. The plant has 13 turbine generators with a total discharge capacity of 102,000 cfs.

Lewiston Pump Generating Plant (LPGP): This plant is located at the east end of the forebay. Generally, water is pumped into the Lewiston Reservoir during non-peak-usage conditions (i.e., at night and on weekends). The water stored in the Lewiston Reservoir is used for power generation during peak-usage periods (i.e., daytime Monday through Friday). The plant has 12 pump turbines, although not all units are necessarily used during pumping or power generation. The total generating capacity of the station under normal conditions is approximately 330 MW, and the forebay serves as the tailwater during power generation.

1.2.2 Lewiston Reservoir

The reservoir was built above ground and is surrounded by a rock-filled dike with an impervious clay core (Figure 1.2.2-1). It has a circumference of 6.5 miles. The reservoir has a gross storage capacity of 74,250 acre-feet (24 billion gallons). The usable storage capacity is 69,500 acre-feet, or 94% of the gross storage capacity. The maximum water surface elevation is 658 feet U.S. Lake Survey Datum 1935 (USLSD). When the reservoir is at maximum water elevation, the water depth is about 42 feet and the surface area is 1,900 acres (Figure 1.2.2-2). At maximum reservoir drawdown to an elevation of 620 feet, the average water depth of the wetted areas is just over 3 feet (NYPA 2002).

In general, from Monday through Friday, the daily net drawdown in the reservoir is approximately 6 to 7 feet. The water level of the reservoir is usually at its lowest near the end of the week (Figure 1.2.2-3). During the weekend, the reservoir is typically refilled, bringing the reservoir water level back to its maximum elevation on Monday morning. Typically, in the summer and fall, the reservoir is drawn down to an elevation of approximately 625 feet by Friday (see Appendix A for detailed water level data). At this elevation, 15% of the gross storage capacity remains in the reservoir. The withdrawal and regeneration pattern from July 16 to 23, 2001, reflects the typical high replacement rate of water in the reservoir (Figure 1.2.2-3). The changes in the storage capacity based on the pattern in Figure 1.2.2-3 relative to the total storage capacity are as follows:

Elevation Percent of Gross Storage

Day Time (USLSD 1935) Capacity Remaining

Monday 6:00h 658.0 100%

Monday 21:00h 636.4 44%

Tuesday 6:00h 648.9 76%

Tuesday 22:00h 630.1 28%

Wednesday 6:00h 643.3 62%

Wednesday 21:00h 623.7 12%

Thursday 6:00h 639.1 51%

Thursday 21:00h 622.8 10%

Friday 7:00h 639.3 51%

Friday 20:00h 628.3 23%

Saturday 7:00h 644.3 64%

Saturday 19:00h 639.8 53%

Sunday 7:00h 655.8 94%

Sunday 19:00h 644.6 65%

During the non-tourist season (i.e., November through March), drawdown of the Lewiston Reservoir to 625 feet is less common since water levels are higher because storage in the lowest part of the reservoir is held in reserve in case it is needed to compensate for reduced diversion caused by ice problems (URS et al. 2005a; see Appendix A for water level data for year 2002).

On average, the water surface elevation in the reservoir is approximately two thirds of the maximum elevation. Between years 1991 and 2002, the mean annual water elevation in the reservoir ranged from 641.3 to 646.4 feet USLSD; the minimum annual water elevation ranged from 620.2 to 626.9 feet; the maximum elevation ranged from 658.5 to 658.8 feet (Table 1.2.2-1).

Table 1.2.2-1

Lewiston Reservoir - Water Level Statistics (in feet USLSD 1935)

January

February

March

April

Year

Min

Max

Mean

Min

Max

Mean

Min

Max

Mean

Min

Max

Mean

1991