Effects of a Cattail Wetland on

Water Quality of Irondequoit Creek

near Rochester, New York

U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 00-4032

Prepared in cooperation with the

MONROE COUNTY DEPARTMENT OF HEALTH
U.S. GEOLOGICAL SURVEY

Water-Resources Investigations Report 00-4032

Effects of a Cattail Wetland on Water Quality of 

Irondequoit Creek near Rochester, New York

Prepared in cooperation with the

MONROE COUNTY DEPARTMENT OF HEALTH

By WILLIAM F. COON, JOHN M. BERNARD, AND FRANZ K. SEISCHAB

Ithaca, New York

2000
U.S. DEPARTMENT OF THE INTERIOR

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY

Gordon P. Eaton, Director

For addtional information write to: Copies of this report can be purchased

from:

U.S. Geological Survey

Branch of Information Services

Box 25286

Denver Federal Center

Denver, CO 80225-0046

ii

Subdistrict Chief

U.S. Geological Survey

30 Brown Road

Ithaca, NY14850

The use of trade, product, or firm names in this report is for identification or location purposes only and

does not constitute endorsement of products by the U.S. Geological Survey, nor impute responsibility

for any present or potential effects on the natural resources of the United States.
Contents III

CONTENTS

Abstract ................................................................................................................................................................................. 1

Introduction .......................................................................................................................................................................... 2

Irondequoit Creek Basin.............................................................................................................................................. 3

Previous Studies................................................................................................................................................. 3

Ellison Park Wetland.......................................................................................................................................... 4

Purpose and Scope....................................................................................................................................................... 5

Study Area .................................................................................................................................................................. 6

Precipitation....................................................................................................................................................... 6

Location ............................................................................................................................................................. 6

Wetland Characteristics ..................................................................................................................................... 7

Hydrology.......................................................................................................................................................... 8

Acknowledgment ........................................................................................................................................................ 10

Methods ................................................................................................................................................................................. 10

Data Collection ............................................................................................................................................................ 10

Surface Water..................................................................................................................................................... 10

Stream Discharge..................................................................................................................................... 10

Temperature ............................................................................................................................................. 11

Water Quality .......................................................................................................................................... 11

Sediment Quality .............................................................................................................................................. 11

Flora Survey, Plant-Tissue Analyses, and Biomass Measurements................................................................... 11

Quality-Assurance and Quality-Control Program ...................................................................................................... 12

Computation of Constituent Loads and Removal Efficiency ...................................................................................... 14

Effects of Wetland on Water Quality ................................................................................................................................... 17

Constituent Loads and Removal Efficiencies .............................................................................................................. 19

Nitrogen ............................................................................................................................................................. 20

Phosphorus ........................................................................................................................................................ 27

Suspended Solids .............................................................................................................................................. 29

Chloride and Sulfate .......................................................................................................................................... 31

Trace Metals ................................................................................................................................................................ 34

Water Temperature....................................................................................................................................................... 39

Characteristics of Wetland Sediments ........................................................................................................................ 39

Characteristics of Wetland Vegetation (Typha glauca) ............................................................................................... 41

Density and Biomass ........................................................................................................................................ 41

Nutrients and Trace Metals................................................................................................................................ 42

Chemical Standing Stocks ................................................................................................................................ 43

Water-Quality-Improvement Function of Ellison Park Wetland ................................................................................. 44

Progress Toward Water-Quality Improvement of Irondequoit Bay ............................................................................. 45

Trophic Status.................................................................................................................................................... 45

Temporal Trends in Chemical Loads................................................................................................................. 46

Summary ............................................................................................................................................................................... 48

References Cited.................................................................................................................................................................... 50

FIGURES

1. Map showing location of study area and major geographic features of Irondequoit Creek basin, Monroe 

County, N.Y . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2. Map showing locations of data-collection sites and Ellison Park wetland within the Irondequoit Creek basin, 

Monroe County, N.Y. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
IV Contents

3. Graph showing (A) Monthly precipitation, 1990-96, and normal (1961-90) mean monthly precipitation recorded 

at the Greater Rochester International Airport, Rochester, N.Y., and (B) Monthly mean discharges at Irondequoit 

Creek above Blossom Road and at Empire Boulevard, 1990-96, with monthly maximum, mean, and minimum 

discharges for the period of record at Blossom Road, 1981-96, Monroe County, N.Y. . . . . . . . . . . . . . . . . . . . . . . 7

4. Graph showing daily mean water-surface elevation of Ellison Park wetland as measured at Empire 

Boulevard (wetland outlet), Monroe County, N.Y., 1990-96 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

5. Graph showing concentration of (A) a dissolved constituent (ammonia nitrogen), and (B) a particulate constituent 

(total phosphorus) as a function of discharge in Irondequoit Creek above Blossom Road and at Empire Boulevard, 

Monroe County, N.Y., 1990-96 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

6. Graphs showing monthly load and wetland’s removal efficiency for total nitrogen, Ellison Park wetland, Monroe 

County, N.Y., 1990-96 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

7-15. Graphs showing concentrations, monthly loads, and wetland’s removal efficiency for selected constituents, Ellison 

Park wetland, Monroe County, N.Y., 1990-96

7. Ammonia-plus-organic nitrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

8. Ammonia nitrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

9. Nitrate-plus-nitrite nitrogen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

10. Total phosphorus . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

11. Orthophosphate. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

12. Total suspended solids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

13. Volatile suspended solids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

14. Chloride. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

15. Sulfate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

16. Box plots showing concentrations of selected trace metals in stormwater samples from Irondequoit Creek above 

Blossom Road and at Empire Boulevard, Monroe County, N.Y., 1990-96 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

17. Graphs showing water temperatures at Irondequoit Creek above Blossom Road and at Empire Boulevard, Monroe 

County, N.Y.: A. Monthly mean water temperature, 1994-96. B. Daily mean water temperature, 1996 water year. 

C. Water temperature and D. hydrograph during storm runoff period, June 18-28, 1996 . . . . . . . . . . . . . . . . . . . . . 40

18. Graph showing trophic state of Irondequoit Bay, 1971-96, based on measured chlorophyll_a and computed 

potential-phosphorus concentrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

TABLES

1. Monthly and annual total precipitation recorded at Greater Rochester International 

Airport, Rochester, N.Y., 1990-96, with normal 30-year (1961-90) means . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2. Periods of inundation and average maximum depth of inundation in southern and northern areas 

of Ellison Park wetland, Monroe County, N.Y., 1991-96 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3. Explanatory variables used in regression models developed to compute constituent loads for Irondequoit Creek 

above Blossom Road (wetland inlet) and at Empire Boulevard (wetland outlet), Monroe County, N.Y., 1990-96 . 14

4. Regression statistics for models used to compute constituent loads for Irondequoit Creek above Blossom Road 

(wetland inlet) and at Empire Boulevard (wetland outlet), Monroe County, N.Y., 1990-96 . . . . . . . . . . . . . . . . . . . 16

5. Statistics (p-values) related to tests of significant difference between monthly constituent loads computed 

for Irondequoit Creek above Blossom Road (wetland inlet) and at Empire Boulevard (wetland outlet), Monroe 

County, N.Y., 1990-96 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

6. Spearman correlation coefficients between constituent loads and removal efficiencies and four variables, Ellison 

Park wetland, Monroe County, N.Y., 1990-96. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

7. Concentrations and average annual input and output loads, and removal efficiency, for selected constituents, 

Ellison Park wetland, Monroe County, N.Y., 1990-96 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

8. Selected statistics on trace-metal concentrations in Irondequoit Creek above Blossom Road (wetland inlet) and 

at Empire Boulevard (wetland outlet), Monroe County, N.Y., 1990-96 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

9. Concentrations of selected chemicals in sediment of Ellison Park wetland, Monroe County, N.Y., October 1994. . 41

10. Characteristics of Typha glauca in Ellison Park wetland, Monroe County, N.Y., 1991 and 1996 . . . . . . . . . . . . . . . 42

11. Average dry-weight percentage or concentration of selected elements in above- and below-ground biomass of 

Typha glauca in Ellison Park wetland, Monroe County, N.Y., 1991 and 1996 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

12. Average standing stocks of selected elements in above- and below-ground biomass of Typha glauca in Ellison 

Park wetland, Monroe County, N.Y., 1991 and 1996. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

13. Estimated average annual loads of selected chemical constituents entering Irondequoit Bay, Monroe 

County, N.Y. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
Contents V

APPENDIXES

1. Selected chemical analyses of water samples from Irondequoit Creek above Blossom Road and at Empire 

Boulevard (Ellison Park wetland inflow and outflow sites), Monroe County, N.Y., 1990-96 . . . . . . . . . . . . . . . . . . 54

2. Monthly and annual constituent input and output loads and associated errors for Ellison Park wetland, Monroe 

County, N.Y., 1990-96 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

3. Monthly removal efficiencies for selected constituents as percentage of input load retained in Ellison Park 

wetland, Monroe County, N.Y., 1990-96 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

4. Chemical analyses of four sediment samples collected in the Ellison Park wetland, Monroe County, N.Y., 

October 1994 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
VI Contents

CONVERSION FACTORS, VERTICAL DATUM, AND ABBREVIATED WATER-QUALITY UNITS

Specific conductance is given in microsiemens per centimeter at 25 degrees Celsius (μS/cm at 25  ̊C).

Temperature: degrees Celsius ( ̊C ) = 5/9 (degrees Fahrenheit ( ̊F) minus 32)

Concentrations of chemical constituents in water are given either in:

milligrams per liter (mg/L) ≈ micrograms per gram (mg/g) = parts per million (ppm); or

micrograms per liter (μg/L) ≈ micrograms per kilogram (μg/kg) = parts per billion (ppb)

National Geodetic Vertical Datum of 1929 (NGVD) is a geodetic datum derived from a general adjustment of the first-order 

level nets of both the United States and Canada, formerly called Sea Level Datum of 1929.

INCH-POUND TO INTERNATIONAL SYSTEM (SI) UNITS

Multiply By To obtain

Length

inch (in.) 2.54 centimeter

inch (in.) 25.4 millimeter

foot (ft) 0.3048 meter

mile (mi) 1.609 kilometer

Area

acre 0.4047 hectare

square foot (ft2

) 0.09290 square meter

square mile (mi2

) 2.590 square kilometer 

Volume

cubic foot (ft3

) 0.02832 cubic meter 

acre-foot (acre-ft) 1,233 cubic meter 

Flow rate

cubic foot per second (ft3/s) 0.02832 cubic meter per second 

Mass

ounce, avoirdupois (oz) 28.35 gram 

pound, avoirdupois (lb) 0.4536 kilogram 

ton, short (2,000 lb) 0.9072 megagram 

INTERNATIONAL SYSTEM (SI) TO INCH-POUND UNITS

Multiply By To obtain

Length

centimeter (cm) 0.3937 inch

millimeter (mm) 0.03937 inch

meter (m) 3.281 foot 

kilometer (km) 0.6214 mile 

Area

hectare (ha) 2.471 acre

square meter (m2

) 10.76 square foot 

square kilometer (km2

) 0.3861 square mile

Volume

cubic meter (m3

) 35.31 cubic foot 

cubic meter (m3

) 0.0008107 acre-foot 

Flow rate

cubic meter per second (m3

/s) 35.31 cubic foot per second 

Mass

gram (g) 0.03527 ounce, avoirdupois

kilogram (kg) 2.205 pound, avoirdupois

gram per square meter (g/m2

) .0002049 pound per square foot

megagram (Mg) 1.102 ton, short (2,000 lb)
Abstract 1

Effects of a Cattail Wetland on Water Quality of 

Irondequoit Creek near Rochester, New York

by William F. Coon, John M. Bernard1, and Franz K. Seischab2

ABSTRACT

A 6-year (1990-96) study of the Ellison 

Park wetland, a 423-acre, predominantly cattail 

(Typha glauca) marsh in Monroe County, N.Y., 

was conducted to document the effect that this 

wetland has on the water quality of Irondequoit 

Creek, which flows through it. Irondequoit Creek 

drains 151 square miles of mostly urban and 

suburban land and is the main tributary to 

Irondequoit Bay on Lake Ontario. The wetland 

was a sink for total phosphorus and total 

suspended solids (28 and 47 percent removal 

efficiencies, respectively, over the 6-year study 

period). Sedimentation and vegetative filtration 

appear to be the primary mechanisms for the 

decrease in loads of these constituents. Total 

nitrogen loads were decreased slightly by the 

wetland; removal efficiencies for ammonia-plusorganic nitrogen and nitrate-plus-nitrite were 6 

and 3 percent, respectively. The proportions of 

total phosphorus and total nitrogen constituents 

were altered by the wetland. Orthophosphate and 

ammonia nitrogen were generated within the 

wetland and represented 12 percent of the totalphosphorus output load and 1.8 percent of totalnitrogen output load, respectively. Conservative 

chemicals, such as chloride and sulfate, were little 

affected by the wetland. Concentrations of zinc, 

lead, and cadmium showed statistically significant 

decreases, which are attributed to sedimentation 

and filtration of sediment and organic matter to 

which these elements adsorb. 

Sediment samples from open-water 

depositional areas in the wetland contained high 

concentrations of (1) trace metals, including 

barium, manganese, strontium, zinc (each of 

which exceeded 200 parts per million), as well as 

chromium, copper, lead, and vanadium, and (2) 

some polycyclic aromatic hydrocarbons. 

Persistent organochlorine pesticides, such as 

chlordane, dieldrin, DDT and its degradation 

products (DDD and DDE), and polychlorinated 

biphenyls (PCB’s), also were detected, but 

concentrations of these compounds were within 

the ranges often found in depositional 

environments in highly urbanized areas.

Cattail shoots attained a maximum height 

of 350 centimeters, a density of more than 30 

shoots per square meter, and total biomass of 

more than 5,600 grams per square meter (46 

percent of which was in above-ground tissues 

during the growing season). Nitrogen and 

potassium were three times more abundant in 

above-ground tissues (2.4 and 1.5 percent by dry 

weight, respectively) than in below-ground tissues 

(0.8 and 0.5 percent, respectively). 

Concentrations of phosphorus, molybdenum, and 

manganese in above-ground tissues were similar 

to those in below-ground tissues, but the 

concentrations of all other constituents were 

considerably higher in below-ground tissues. 

Concentrations of several elements exceeded 

those typically found in natural wetlands; these 

included manganese (417 ppm, parts per million) 

and sodium (3,600 ppm) in above-ground tissues, 

and aluminum (1,540 ppm), iron (15,400 ppm), 

1

Department of Biology, Ithaca College, Ithaca, N.Y.

2

Department of Biology, Rochester Institute of Technology, 

Rochester, N.Y.
2 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

manganese (433 ppm), and sodium (10,000 ppm) 

in below-ground tissues. 

Large quantities of nutrients are assimilated 

by wetland vegetation during the growing season, 

but neither tissue production nor microbial 

metabolic processes appeared to play a significant 

role in the observed patterns of surface-water 

chemical input-to-output relations on a seasonal 

basis. Presumably, internal cycling of nutrients 

sequestered in the sediments and detritus, 

combined with a summer increase in microbially 

mediated chemical transformations, obscured the 

effects of vegetative assimilation during the 

summer on surface-water chemical loads. 

Additionally, the natural confinement of most 

flows within the banks of Irondequoit Creek, 

which resulted in passage of stormwater through 

the wetland with little dispersion or detention in 

the cattail and backwater areas, diminished the 

capability of the wetland to improve water quality. 

Additional factors that probably affected the 

chemical-removal efficiency of the wetland 

included chemical inflow loading rates, storage 

and release mechanisms of the sediments 

(sedimentation, adsorption, filtration, 

precipitation, dissolution, and resuspension), and 

accretion and burial of organic matter.

Measurements of chlorophyll_a concentrations, 

and calculations of potential phosphorus 

concentrations, since the 1970’s indicate an 

improvement in the trophic state of Irondequoit Bay. 

Estimated average annual loads (1990-96) of selected 

constituents entering Irondequoit Bay indicate that, 

since 1980, the loads of all major forms of nitrogen 

have decreased, chloride loads have increased, and 

sulfate loads have changed little. Inputs of total 

phosphorus and suspended solids to the wetland have 

increased since 1980, possibly as a result of increased 

erosion by stormflows from an increasingly developed 

watershed. The wetland decreases the loads of these 

constituents, but the trends of these loads entering 

Irondequoit Bay cannot be reliably defined because 

the removal efficiencies during the two earlier study 

periods (1980-81 and 1984-88) are unknown.

INTRODUCTION

Wetlands have been recognized as important 

ecosystems that provide unique habitats for fish, 

wildlife, and plants. They provide many other 

functions and values, including ground-water recharge 

and discharge, flood storage and desynchronization of 

flood waves, shoreline anchoring and dissipation of 

erosive forces, sediment trapping and removal of 

adsorbed chemicals (heavy metals and organic 

compounds), nutrient retention and removal, nutrient 

cycling, food-chain support (production, 

decomposition, consumption, and detrital export), 

recreation (swimming, boating, fishing, nature study), 

and scientific research (Adamus and Stockwell, 1983; 

and Mitsch and Gosselink, 1986). Among these 

functions is the potential to improve water quality by 

facilitating the retention or removal of sediment and 

nutrients carried by urban stormwater. This function 

can be achieved through various processes, including 

sedimentation (settling), adsorption, chemical 

precipitation, filtration, biochemical interactions and 

microbially mediated transformations, nutrient 

assimilation, volatilization and aerosol formation, 

infiltration (Strecker and others, 1992), ion exchange, 

biodegradation (U.S. Environmental Protection 

Agency, 1993), and long-term storage of chemicals 

through accretion and burial (Mitsch and Gosselink, 

1986). These processes can cause a wetland to act as 

either a temporary or permanent sink for certain 

constituents. Other processes, such as leaching, 

decomposition, dissolution, diffusion from sediments, 

and, again, microbially mediated transformations, can 

cause a wetland to act as a source for certain 

constituents by generating these constituents and 

exporting them in quantities larger than those that 

entered the wetland (Kadlec and Knight, 1996; 

Strecker and others, 1992; Mitsch and Gosselink, 

1986; U.S. Environmental Protection Agency, 1993).

Mitsch and Gosselink (1986) note that the 

effects of nutrient uptake by macrophytes, algae, 

bacteria, and fungi on water quality in the wetland can 

be similar to those of secondary and advanced 

treatment of wastewater. Johnston (1991) points out 

that physical and microbial processes in a wetland 

generally have a greater effect than vegetative uptake 

in the retention of sediment and nutrients. Hickok and 

others (1977) conclude that, barring flooded or cold 

soil conditions, which inhibit microbial processes, 

microbial activity is the principal mechanism for 

removing phosphorus from the soil-water solution. 
3

Natural and constructed wetlands have been studied 

since the 1960’s and are receiving widespread use as 

cost-effective and environmentally beneficial means of 

mitigating the deleterious effects of storm runoff and 

wastewater on receiving surface-water bodies and 

ground-water systems (Kadlec and Knight, 1996; 

Strecker and others, 1992; U.S. Environmental 

Protection Agency, 1993; Livingston, 1989; Gadbois, 

1989). One factor that largely determines a wetland’s 

removal efficiency for the primary nutrients 

(phosphorus and nitrogen) is macrophyte density — 

that is, the amount of surface area to which bacteria, 

fungi, and epiphytic algae can adhere (Kadlec and 

Knight, 1996). These microbes facilitate the 

assimilation and transformation of nutrients and form 

a biofilm on substrate surfaces. 

The processes of water-quality improvement in 

a wetland are interrelated, and the relative importance 

of any one mechanism can vary from wetland to 

wetland. The broad range in the effectiveness of 

wetlands in treating stormwater results from (1) the 

diversity among wetlands in terms of vegetation, depth 

and duration of inundation, climatic factors, soils, and 

hydraulic characteristics, and (2) differences in water 

sources (surface water, ground water, or atmospheric 

deposition) and in water chemistry. The balance 

between chemical uptake and retention, and chemical 

release (through leaching, decomposition, and plantfacilitated transfer from the sediments to overlying 

waters) and export (through surface flow and 

atmospheric exchange) determines a wetland’s net 

effect on water quality. Chemical retention or export 

can be affected by many factors, including the 

wetland’s size and water-storage capacity; the rate and 

velocity of flow; the detention time of stormwater; the 

flow pattern and degree of dispersal or mixing 

(circulation); the presence or absence of pools for 

sediment accumulation; the frequency, duration, and 

depth of inundation; the types and density of 

vegetation; the water pH, temperature, dissolvedoxygen concentration, and turbidity or amount of light 

penetration; the season; the types of maintenance 

practices used (removal of sediment or vegetation); 

and the chemical-exchange rates between water and 

sediment (Livingston, 1989; Strecker and others, 

1992; Kadlec and Knight, 1996; Adamus and 

Stockwell, 1983). 

The hydrologic characteristics of a wetland play 

a major role in its structure and water-qualityimprovement function in that they (1) determine or 

modify the composition, diversity, and distribution of 

wetland flora; (2) affect the level of productivity 

through volume and circulation of flow and through 

duration and frequency of inundation; and (3) affect 

(a) rates of sedimentation, resuspension, and erosion; 

(b) rates of organic accumulation and export; and (c) 

the input, output, transformation, and cycling of 

nutrients and other constituents (Mitsch and 

Gosselink, 1986). 

Irondequoit Creek Basin

The Irondequoit Creek basin, east and southeast 

of Rochester, in Monroe and Ontario Counties, has 

been the subject of numerous water-quality studies in 

response to public concern over the sedimentation and 

eutrophication of Irondequoit Bay on Lake Ontario 

(fig. 1). Irondequoit Creek, the bay’s main tributary, is 

the source of (1) nutrients that, in the past, supported 

summertime algal blooms in the bay (Pixley, 1982); (2) 

dissolved chloride, which can alter the bay’s chemical 

and thermal stratification and interfere with seasonal 

mixing of the bay’s waters (Diment and others, 1974; 

Bubeck and Burton, 1989); and (3) sediment to which 

heavy metals and organic compounds can adhere 

(Schroeder, 1985). Until the spring of 1977, effluent 

from 14 wastewater-treatment facilities within the basin 

and combined-sewer overflows from the city of 

Rochester were discharged into the creek (M. Schifano, 

Monroe County Pure Waters, oral commun., 1999). At 

present, these wastewaters are treated at a central 

location at the north end of Rochester and are 

discharged into Lake Ontario. These diversions of 

wastewater out of the basin have improved the water 

quality of Irondequoit Bay, but further improvement 

has been slowed by the continued input of contaminants 

from nonpoint sources in the basin—primarily 

nutrients, metals, and organic compounds washed from 

impervious surfaces by rain and snowmelt (R. Burton, 

Monroe County Environmental Health Laboratory, 

written comm., 1996).

Previous Studies

The hydrologic characteristics of the 

Irondequoit Creek basin were studied during 1979-81 

as part of the Nationwide Urban Runoff Program 

(NURP) (O’Brien and Gere, 1983; Zarriello and 

others, 1985; Kappel and others, 1986). One goal of 

that study was to assess the effect of storm runoff and 
4 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

its associated nutrients and contaminants on the 

quality of water in Irondequoit Bay. Kappel and 

others (1986) estimated annual loads (1980-81) 

of selected constituents that entered the bay: 

214 tons of ammonia-plus-organic nitrogen, 

20.2 tons of total phosphorus, and 19,100 tons 

of total suspended solids. O’Brien and Gere 

(1983, p. iv) used a steady-state model and 

estimated that 15.7 tons of phosphorus were 

entering Irondequoit Bay annually (1980-81) 

from external sources and that, from an 

assumption of a zero net phosphorus release 

from the bottom sediments of the bay, the 

external loading would need to be decreased to 

about 5.6 tons annually to maintain the bay in a 

trophic state appropriate for recreational usage. 

They also indicated that 50 to 75 percent of the 

annual phosphorus loads entered the bay during 

a 3-month period that included the major 

seasonal snowmelt and spring runoff. A unique 

component of the Irondequoit Creek NURP 

study (Kappel and others, 1986) was the 

inclusion of an in-stream natural wetland 

(Ellison Park) in the study’s monitoring 

program (fig. 2). Several NURP projects 

considered wetlands to be promising 

mechanisms for treatment of urban runoff, but 

these projects did not include development of 

performance or design criteria (U.S. 

Environmental Protection Agency, 1983). 

Ellison Park Wetland

The Irondequoit Creek NURP study 

identified the large, predominantly cattailcovered Ellison Park wetland near the mouth of 

Irondequoit Creek, just south of Irondequoit 

Bay, as the most cost-effective means of decreasing 

nutrient loads entering the bay (O’Brien and Gere, 

1983). Kappel and others (1986) estimated that the 

wetland provided a 10-percent decrease in phosphorus 

loads and theorized that an additional 15 percent 

decrease (primarily through deposition and 

mineralization of particulate phosphorus associated 

with the silt-clay sediment fraction) could be achieved 

if flows through the wetland were regulated and waterdispersal and detention time increased. Similarly, 

O’Brien and Gere (1983) estimated an annual 

phosphorus removal of 24 percent could be attained 

through operation of a flow-control structure installed 

at a natural constriction in the wetland midway 

between Browncroft and Empire Boulevards (fig. 2).

In 1990, the U.S. Geological Survey (USGS), in 

cooperation with the Monroe County Department of 

Health, began a 6-year study of the wetland to evaluate 

its potential for water-quality improvement. 

Streamflow and water chemistry of Irondequoit Creek 

at the upstream and downstream ends of the wetland 

were monitored. Concurrent biological studies of the 

fish, bird, and benthic-macroinvertebrate communities 

in the wetland were conducted (Miller and Ringler, 

1992). Wetland flora and vegetation studies were 

conducted in 1991 and 1996 (Bernard and Seischab, 

Lake

Ontario

City of Rochester

Irondequoit

Bay

Irondequoit Creek

MONROE COUNTY

ONTARIO COUNTY

WAYNE COUNTY

LIVINGSTON COUNTY

Erie (Ba rge) Ca nal

MONROE COUNTY

Gen ese

e

R

vi er

1 2 3 4 5 MILES

0 1 2 3 4 5 KILOMETERS

0

Base from U.S. Geological Survey 

State base map 1:500,000

43 ̊

43 ̊

07'

30"

43 ̊

15'

77 ̊37'30" 77 ̊30' 77 ̊22'30"

Ellison Park

wetland

(Area shown

in Figure 2.)

LOCATION MAP

Irondequoit

Creek Basin NEW

YORK

Greater

Rochester

International

Airport

Figure 1. Location of study area and major geographic features of 

Irondequoit Creek basin, Monroe County, N.Y.
5

1000 2000 FEET

0 250 500 METERS

0

Base from scanned U.S. Geological Survey

Rochester East, NY 1:24,000, 1978

43 ̊9'

10'

77 ̊ 32' 77 ̊31'

EXPLANATION

Wetland boundary

Streamflow-measurement and waterquality analysis site. Number is

USGS streamflow gage number.

Atmospheric-deposition collector

Observation well

0423205010

43 ̊

Irondequoit

Brighton

Penfield

E

L

L

I

S

O

N

P

ARK

Sediment-quality analysis site

Flora transect

Town boundary

Millrace

0423205025

I r o n d e q u o i t Creek

Blossom Road

0423205010

NYS Route 590

Browncroft

Empire

Boulevard

The Narrows

Irondequoit

Boulevard

B a y

1991 and 1997) between Browncroft and Empire 

Boulevards to (1) identify individual species, (2) map 

plant communities, (3) measure cattail density (shoots 

per square meter) and above- and below-ground 

biomass, and (4) provide chemical analyses of aboveand below-ground cattail tissues. 

A description of the hydrologic, 

sedimentological, and biological characteristics of the 

wetland is given by Coon (1997), who noted that (1) 

water levels in the wetland are controlled by the 

surface elevation of Lake Ontario; (2) bankfull and 

lower flows of Irondequoit Creek do not disperse 

through the wetland, but are mostly confined within 

the banks of the main channel and usually pass 

through the wetland in less than 3.5 hours; dispersal of 

stormflows occurs only when flows exceed the 

capacity of the channel (overbank flows), which on 

average occurs twice a year; (3) dispersed water 

moves into the cattail-covered backwater areas of the 

wetland, where it can be detained for 3 to 15 hours or 

more (the maximum detention time has not been 

determined); (4) dispersal of flows also occurs during 

backwater conditions that result from high water levels 

on Lake Ontario, usually from April to July; (5) the 

channel sediments in the wetland range from sand, 

which is found in the main channel of Irondequoit 

Creek, to silt and clay with a high concentration of 

organic matter (about 4 percent total organic carbon by 

weight), in the backwater areas; (6) sedimentation in 

the wetland is sporadic, but an annual sedimentation 

rate from 0.006 to 0.016 ft has been estimated. Data on 

the biological structure of the wetland are summarized 

in Coon (1997) and include (1) the identification and 

distribution of fish species during 1991-92 (Miller and 

Ringler, 1992); (2) results of the bird surveys 

conducted during 1980-85 (Andrle and Carroll, 1988) 

and 1991-92 (Miller and Ringler, 1992); (3) a cursory 

description of the macroinvertebrate community based 

on the analyses of the stomach contents of fishes 

(Miller and Ringler, 1992); and (4) a general 

description of the wetland flora (Bernard and 

Seischab, 1991).

Purpose and Scope

This report (1) presents Ellison Park wetland’s 

monthly and annual inflow and outflow loads of total 

nitrogen, ammonia-plus-organic nitrogen, ammonia, 

organic nitrogen, nitrate-plus-nitrite nitrogen, total 

phosphorus, orthophosphate, total and volatile 

suspended solids, chloride, and sulfate, during the 

1990-96 water years (a water year is the period from 

October of one year to September of the following 

year); (2) gives the wetland’s computed monthly and 

Figure 2. Locations of data-collection sites and Ellison 

Park wetland within the Irondequoit Creek basin, Monroe 

County, N.Y. (Location is shown in fig. 1.)
6 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

annual removal efficiencies for the above constituents; 

(3) assesses the effect of the wetland on surface-water 

temperature; (4) describes the physical and chemical 

characteristics of the vegetation and recently deposited 

sediment in the wetland; (5) discusses the role of the 

wetland sediment and vegetation, primarily cattail 

(Typha glauca), in the retention or export of nutrients; 

and (6) assesses the current ecological status of 

Irondequoit Bay in terms of trophic state and trends in 

estimated constituent loads entering the bay. Detailed 

chemical analyses of water and sediment samples are 

given in the appendixes.

Study Area

The Irondequoit Bay watershed covers an area 

of 169 mi2 (fig. 1), of which 151 mi2 is drained by 

Irondequoit Creek, which flows into the south end of 

Irondequoit Bay. About 54 percent of the watershed is 

urban or suburban, and about 34 percent is 

agricultural (Christopher Sciacca, Monroe County 

Planning Board, written commun., 1998). The 

upstream (southern) part of the basin is dominated by 

forest and agricultural areas but is becoming 

increasingly developed. 

Precipitation

Average annual precipitation in the Rochester 

area is 32.4 in. (168 years of record), including that 

from an average snowfall of about 90 in. (55 years of 

record), as recorded by the National Weather Service 

station at the Greater Rochester International Airport 

(National Climatic Data Center, 1996). Monthly 

precipitation quantities during the 1990-96 study period 

(table 1) are plotted with 30-year (1961-90) mean 

monthly precipitation values in figure 3A. Monthly 

precipitation greatly exceeded the long-term average 

during July 1992, October 1995, and June 1996, and 

was substantially below average during February and 

June 1991; May, July and August 1993; July and 

October 1994; and February through June 1995.

Location

The wetland (referred to in this report as the 

Ellison Park wetland) lies at the mouth of Irondequoit 

Creek along the township boundaries of Irondequoit, 

Brighton, and Penfield in Monroe County (fig. 2). The 

wetland, which forms a transition zone between the 

riparian environment of the creek and the lacustrine 

environment of Irondequoit Bay, encompasses about 

423 acres at and below an elevation of 250 ft 

(DeGaspari and Bannister, 1983) and covers less than 

0.5 percent of the creek’s total drainage area. Bounded 

by steep valley sides on the east and west, it covers the 

entire valley floor from Blossom Road to Empire 

Boulevard. Between Browncroft and Empire 

Boulevards, the wetland is dominated by cattails and is 

divided into southern and northern segments 

(263 acres and 160 acres, respectively, DeGaspari and 

Bannister, 1983) by a natural constriction that is 

locally referred to as the Narrows (fig. 2). The width of 

the wetland ranges from 200 ft at the Narrows to 

2,500 ft in the southern and northern parts. 

Table 1. Monthly and annual total precipitation recorded at Greater Rochester International Airport, 

Rochester, N.Y., 1990-96, with normal 30-year (1961-90) means

[Data from National Climatic Data Center (1996). Values are in inches. Location is shown in fig. 1] 

Year

Monthly

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Annual

1990 1.61 3.93 1.56 3.58 5.76 2.88 3.05 3.59 3.36 4.37 2.27 4.18 40.14

1991 1.69 1.16 4.70 4.07 2.43 1.19 2.37 1.80 2.86 1.65 2.39 2.92 29.23

1992 1.46 1.87 3.53 3.43 2.83 1.98 6.03 4.45 3.02 1.78 2.90 2.98 36.26

1993 2.32 1.52 2.44 3.07 1.24 2.76 1.67 1.67 4.37 3.21 3.27 1.60 29.14

1994 2.68 1.63 1.70 4.08 2.56 2.43 0.61 4.27 2.68 1.34 3.24 2.32 29.54

1995 2.46 1.58 1.15 1.18 1.75 2.07 3.85 3.05 1.50 5.70 4.21 1.50 30.00

1996 3.18 1.72 2.07 4.84 3.51 6.65 2.18 3.33 5.09 5.40 4.12 2.97 45.06

Normal mean,

1961-90 2.08 2.10 2.28 2.61 2.72 3.00 2.71 3.40 2.97 2.44 2.92 2.73 31.96
7

1991 1992 1993 1994 1995 1996

0

8

2

4

6

PRECIPITATION, IN INCHES

Monthly precipitation

30-year normal mean monthly precipitation (1961-90)

A. PRECIPITATION

1991 1992 1993 1994 1995 1996

0

500

100

200

300

400

DISCHARGE, IN CUBIC FEET PER SECOND 

Mean 

Maximum

Minimum 

B. DISCHARGE

EXPLANATION

Monthly mean discharge for this study (1991-96)

Blossom Road

 Empire Boulevard

Monthly discharge at Blossom Road for period of record (1981-96)

Figure 3. A. Monthly precipitation, 1990-96, and normal (1961-90) mean monthly precipitation, recorded at the Greater 

Rochester International Airport, Rochester, N.Y. B. Monthly mean discharges at Irondequoit Creek above Blossom Road and at 

Empire Boulevard, 1990-96, with monthly maximum, mean, and minimum discharges for the period of record at Blossom Road, 

1981-96, Monroe County, N.Y. (Locations are shown in figs. 1 and 2.)

Wetland Characteristics

The Ellison Park wetland is classified as a 

palustrine persistent emergent wetland by the U.S. 

Fish and Wildlife Service (Cowardin and others, 

1979); that is, a nontidal marsh characterized by erect, 

rooted, herbaceous hydrophytes that may be 

temporarily or permanently flooded at the base and 

normally remain standing at least until the beginning 

of the next growing season. Cattails, primarily Typha 

glauca, cover about 265 acres, or 63 percent of the 

wetland surface area, which is most of the unponded 

area of the wetland between Browncroft and Empire 
8 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

Boulevards. (Acreages were digitized from a USGS 

7.5-minute topographic map, Rochester East, N.Y. 

quadrangle.) Plant diversity is greatest on the banks of 

the main channel of Irondequoit Creek and along the 

wetland margins, where soil wetness varies with slight 

elevation differences. Open-water areas, including 

channels, cover about 99 acres, or 23 percent of the 

wetland. A hardwood-forested wetland between 

Browncroft Boulevard and Blossom Road covers 

about 25 acres, or 6 percent of the wetland, and 

maintained grass areas of the county park below the 

wetland-demarcation elevation of 250 ft (National 

Geodetic Vertical Datum, NGVD) cover the rest of the 

wetland (about 34 acres, or 8 percent of the wetland).

The Ellison Park wetland contains hydric soil, 

defined by the U.S. Soil Conservation Service (1985) 

as soil that in its undrained condition is saturated, 

flooded, or ponded long enough during the growing 

season to develop anaerobic conditions that favor the 

growth and regeneration of hydrophytic vegetation. It 

is a mineral soil, formed through the deposition of 

alluvium (flood-plain deposits) from the Irondequoit 

Creek basin. The upper layer consists of a dense 

accumulation of partly decomposed organic material.

Hydrology

Wetland conditions in Ellison Park are wholly or 

partly dependent on the surface elevation of Lake 

Ontario, which is maintained within a narrow range 

through regulation of control structures on the St. 

Lawrence Seaway. Data collected at a streamflowmonitoring station at Empire Boulevard indicate that 

water-surface elevations at the mouth of the wetland 

fluctuated only 4.1 ft during 1990-96 (fig. 4). Lake 

Ontario water levels usually rise during the springrunoff period and are maintained through the summer 

for navigational and recreational purposes and for 

hydroelectric-power generation on the St. Lawrence 

River near Massena, N.Y. Water levels are lowered in 

December and January to increase the storage capacity 

for spring runoff (Paul Yu, U.S. Army Corps of 

Engineers, oral commun., 1997). When the watersurface elevation recorded at the streamflowmonitoring site at Empire Boulevard is at or above 

246.9 ft, most of the cattail-covered area in the 

southern and northern wetland sections is inundated. 

At a slightly lower elevation, 246.5 ft, the water levels 

in the southern wetland area drop below land surface, 

and only the northernmost part of the northern wetland 

area remains inundated. Water levels range from 2 ft or 

more above land surface to 1.5 ft below. Flat vegetated 

areas of the wetland can be briefly inundated by runoff 

from large storms and are seasonally inundated for 

periods of 4 to 7 months. The duration of seasonal 

inundation (hydroperiod) varies from year to year and 

from south to north; in some years, the water level 

rises only enough to inundate the southern wetland 

area for several days, but in other years, high water 

levels can persist from January through August (fig. 4 

and table 2). The 6 years of water-level data from this 

study (1990-96) show that the hydroperiod averaged 

136 days per year in the southern wetland area and 189 

days per year in the northern wetland area. The 

maximum depth of inundation during these periods 

ranged from 0.1 to 2.4 ft (average 1.1 ft) in the 

southern wetland area, and from 0.5 to 2.8 ft (average 

1.5 ft) in the northern area. 

Two channels convey water through the 

wetland—the main channel of Irondequoit Creek, 

which carries most of the flow, and a smaller channel, 

locally referred to as the Millrace, which formerly was 

the outlet raceway for a flour mill on the east bank of 

the creek just upstream from Blossom Road but 

currently is a diversion from the main channel 

downstream from Blossom Road to the eastern part of 

the southern wetland area north of Browncroft 

Boulevard. In the vicinity of Blossom Road, the main 

channel is about 70 ft wide and from 10 to 12 ft deep 

at bankfull stage, whereas the Millrace is 20 to 25 ft 

wide and 5 to 6 ft deep. Between Browncroft 

Boulevard and the Narrows, the main channel 

dimensions decrease to a bankfull width of 50 to 60 ft 

and depth of 5 to 8 ft. The extension of the Millrace 

channel into the southern wetland area widens to about 

50 ft but is only about 3 ft deep. North of the Narrows, 

the depth of Irondequoit Creek generally continues to 

decrease to 3 or 4 ft. 

Low flows usually occur during late summer; 

whereas peak flows result from snowmelt and rain 

during late winter and spring, and from summer 

thunderstorms. Daily mean flow in the creek, based on 

16 years of record at the inflow-monitoring site 

(Blossom Road), exceeded 45 ft3

/s 90 percent of the 

time, 87 ft3

/s 50 percent of the time, and 251 ft3/s 10 

percent of the time (Hornlein and others, 1997). 

Annual peak discharges ranged from 658 ft3

/s 

(November 2, 1994) to 1,710 ft3

/s (April 2, 1993) and 

usually exceeded 1,000 ft3

/s. Overbank flows occur 

twice a year on average. Overbank flows causing 

inundation of the Ellison Park wetland occurred 3 to 4 
9

1991 1992 1993 1994 1995 1996

245

250

246

247

248

249

WATER-SURFACE ELEVATION ABOVE NGVD, IN FEET

Elevation above which most of the

 cattail-covered area of the southern

 part of the wetland is inundated.

Elevation above which most of the

 cattail-covered area of the northern

 part of the wetland is inundated.

Figure 4. Daily mean water-surface elevation of Ellison Park wetland as measured at Empire Boulevard (wetland outlet), 

Monroe County, N.Y., 1990-96. (Location is shown in fig. 2.)

Table 2. Periods of inundation and average maximum depth 

of inundation in southern and northern areas of Ellison Park 

wetland, Monroe County, N.Y., 1991-96

[ft, feet. Locations are shown in fig. 2.]

Water 

Year1

1

Water year is the period from October of one year to September of 

the following year. 

Southern wetland area Northern wetland area

Period of 

inundation 

(days)

Average 

maximum 

depth (ft)

Period of 

inundation 

(days)

Average 

maximum 

depth (ft)

1991 194 1.5 234 1.9

1992 155 0.8 194 1.2

1993 230 2.4 289 2.8

1994 113 0.7 157 1.1

1995 1 0.1 100 0.5

1996 121 1.1 159 1.5

Mean 136 1.1 189 1.5

times yearly in 1990-92 and 1994, and once in 1993, 

which was the 16-year period-of-record peak flow; 

then did not occur at all in 1995. Monthly mean 

discharges of Irondequoit Creek above Blossom Road 

and at Empire Boulevard during the study period 

(fig. 3B) were below average for two extended 

periods—June 1991 through February 1992 and 

October 1994 through September 1995. The period-ofrecord peak discharge occurred during a period of 

above-average flow, March to April 1993. Monthly 

discharges also were above average from December 

1990 through April 1991, July 1992 through January 

1993, and March through April 1994.

The slope of the main channel decreases from 

about 0.003 upstream from the Blossom Road 

streamflow-monitoring site (measured from USGS 7.5-

minute topographic maps, Rochester East and Fairport, 

N.Y., quadrangles) to 0.0006 within the wetland from 

Blossom Road to Empire Boulevard (from survey 

data). This decrease in channel gradient, in conjunction 

with the wide wetland flood plain, promotes the 

sedimentation and filtering functions of the wetland 

and the attenuation of peak flows. Time-of-travel and 

flow-dispersion studies conducted in the wetland 

during 1991 (Coon, 1997) indicate the following: 

(1) Medium-to-high flows (600 to 800 ft3

/s) in 

the main channel are contained by banks that are 

higher than the cattail-covered areas beyond and move 

through the wetland with little dispersal into the cattail 

areas. The high banks are a result of preferential 

sediment deposition at the point where overbank flow 
10 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

velocities decrease and sediment is trapped by the 

dense vegetation along the bank tops. 

(2) Overbank flows (greater than about 

900 ft3/s) disperse through the cattail-covered areas. 

(3) Water that leaves the main channel and flows 

through the Millrace into the backwater area of the 

southern part of the wetland becomes detained in that 

area for 3 to 15 hours or more; the maximum detention 

time has not been determined. The channel in this part 

of the wetland is shallower than the main channel and 

does not have well-defined banks; therefore, high 

flows are not confined to the channel and easily move 

into and through the adjacent cattail areas. 

(4) Dispersal and detention of flows in both 

channels is facilitated by backwater from high water 

levels in Irondequoit Bay and Lake Ontario. 

Increasing the detention time and the dispersal 

of stormflows, or maximizing the conditions that 

facilitate these results, presumably could result in 

water-quality improvement. Therefore, modifications 

were made to increase flow into the Millrace and into 

the eastern part of the southern wetland area, where 

detention and dispersal occur naturally. Discharge 

measurements made during 1991 indicated that the 

Millrace could convey as much as a quarter of the total 

flow during low-flow periods but carried a decreasing 

proportion of the flow as total flow in the creek 

increased (Coon, 1997). The diversion from the main 

channel to the Millrace downstream from Blossom 

Road was modified during the summer of 1994 by 

lowering and paving the top of the bank above the two 

diversion culverts (48-in.- and 36-in.-diameter pipes); 

thereby increasing flows in the Millrace for nearbankfull discharges. 

Ground-water movement in the unconfined 

aquifer of the lower Irondequoit Creek basin moves 

from the valley walls toward Irondequoit Creek and 

underflow moves northward (downgradient) toward 

Irondequoit Bay and Lake Ontario (Yager and others, 

1985). High water levels in the creek might cause 

short-term reversal of groundwater flow by recharging 

the streambank and flood-plain deposits, but generally 

the Ellison Park wetland is a ground-water discharge 

point (Kappel and Young, 1989). 

Acknowledgments

Thanks are extended to the employees of 

Monroe County Environmental Health Laboratory 

(MCEHL) who assisted in the maintenance and 

operation of the streamflow- and water-qualitymonitoring sites and analyzed water samples. Richard 

Burton, laboratory administrator, provided guidance 

and suggestions throughout the data-collection period.

METHODS 

The study included (1) collection and chemical 

analyses of surface-water, sediment, and cattail-tissue 

samples, (2) a program to assess the accuracy and 

validity of streamflow and water-quality data provided 

by the cooperating agency (Monroe County 

Environmental Health Laboratory), and (3) use of a 

USGS chemical-load estimation program (Cohn and 

others, 1989) to compute surface-water constituent 

loads in the wetland inflow and outflow. Each of these 

is described below. 

Data Collection

The following paragraphs describe (1) field 

methods for the measurement of surface-water stage, 

velocity, and temperature, the collection of water and 

sediment samples, and the survey of the wetland flora 

and collection of cattail-tissue samples, and (2) 

laboratory methods used for chemical analyses of 

water, sediment, and cattail-tissue samples.

Surface Water

Stream discharge and water temperature were 

measured, and water samples collected, at the inlet 

(Blossom Road) and outlet (Empire Boulevard) of the 

Ellison Park wetland. Each monitoring station 

included an electronic data logger, water-stage and 

temperature sensors, and an automatic water sampler. 

The outlet station also had a water-velocity sensor. 

Sensors made measurements every 15 minutes, and 

the measured values were stored in the data loggers. 

Stream Discharge

The upstream monitoring site was 4,000 ft 

(channel distance) above Blossom Road (fig. 2). 

Discharge was computed from a stage-to-discharge 

relation by standard USGS procedures for gaging 

streamflow (Carter and Davidian, 1968; Rantz and 

others, 1982), measuring stage and discharge 

(Buchanan and Somers, 1968 and 1969, respectively), 

and analyzing stage-to-discharge relations (Kennedy, 
11

1984). Periodic field measurements of discharge were 

made to identify any deviations from the established 

stage-to-discharge relation. The downstream site (fig. 

2) was on the bank of the short channel that connects 

the wetland with Irondequoit Bay. Computation of 

discharge for this site was complicated by backwater 

conditions caused by fluctuating water levels in 

Irondequoit Bay and Lake Ontario. Therefore, water 

velocity was measured with an acoustic velocity 

meter (AVM), and the recorded velocity was 

correlated with the mean velocity in the channel as 

calculated from discharge measurements made from 

the Empire Boulevard bridge. Discharge was 

computed from this relation and from the relation 

between stage and flow area. Standard USGS 

procedures for gaging streamflow with an AVM and 

analyzing stage-and-velocity-to-discharge relations 

(Laenen, 1985) were followed.

Temperature

Water temperatures were measured at each site 

intermittently during 1990-94 and continuously (every 

15 minutes) from December 1994 through September 

1996. The continuous measurements were made by 

temperature probes connected to the data loggers. 

Temperatures were measured manually during site 

inspections to verify the recorded temperatures and to 

permit correction, if necessary. 

Water Quality

Automated samplers, which extracted water 

samples from the channel (near the centroid of flow) 

hourly and stored them in refrigerated bottles, were 

maintained by the Monroe County Environmental 

Health Laboratory (MCEHL). Samples were 

composited on the basis of discharge. If base-flow 

conditions prevailed during the entire sampling cycle 

(3 to 4 days), all samples were composited, and a 

single analysis was performed. During storms, 

samples were composited to represent conditions 

during the rising and falling phases of the storm 

hydrograph, and one or two near-peak samples were 

analyzed separately. Laboratory analyses were done 

by MCEHL, which participated in the USGS qualityassurance program for cooperating analytical 

laboratories. Analytical procedures are described in 

American Public Health Association and others 

(1995). Samples were analyzed for phosphorus (total 

and orthophosphate), nitrogen (total, ammonia-plusorganic, nitrate-plus-nitrite, and ammonia), chloride, 

sulfate, and suspended solids (total and volatile). 

Samples collected during stormflows, and periodically 

during low-flow periods, were analyzed additionally 

for total organic carbon, biochemical and chemical 

oxygen demand, alkalinity, specific conductance, and 

trace metals (zinc, lead, copper, and cadmium). (See 

Appendix 1.)

Sediment Quality

The chemical quality of sediment in the Ellison 

Park wetland was assessed through analyses of three 

fine-grained samples (plus one duplicate sample) 

collected in October 1994 from two sites in the 

backwater areas of the southern part of the wetland 

and one site in the northern part (fig. 2). These sites 

were within open-water long-term depositional areas 

and distant from channels that might carry highvelocity, erosive flows. Samples were carefully 

scooped under shallow water from the top 2 to 3 in. of 

sediment, packed in ice and shipped to the USGS 

National Water Quality Laboratory in Arvada, Colo., 

and analyzed by methods described by Shelton and 

Capel (1994) and Radtke (1997). The sediment 

fraction with particle sizes less than 2 mm (sand size 

and smaller), which constituted 100 percent of each 

sample, was analyzed for (1) polycyclic aromatic 

hydrocarbons by gas chromatography with a massspectrometric detector, and (2) organochlorine 

compounds by gas chromatography with electroncapture detectors as described in Wershaw and others 

(1987). The clay fraction (particle size less than 63 

micrometers) was analyzed for major and trace 

elements following procedures listed in Timme (1995) 

and described in Fishman and Friedman (1989). 

Flora Survey, Plant-Tissue Analyses, and Biomass 

Measurements

Wetland-flora studies conducted during 1991 

and 1996 included (1) identification of individual 

species, (2) mapping of plant communities, (3) 

measurements of cattail density and above- and belowground biomass, and (4) chemical analyses of aboveand below-ground tissues of cattails. During the 1991 

study, flora identification and mapping, and 

measurements of cattail density, were conducted on 

June 5 and July 5; cattail tissues for biomass 

calculations and chemical analyses were collected 

between August 15 and September 10. All components 
12 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

of the 1996 study were conducted between July 25 and 

August 25. 

Two permanent transects (fig. 2) were 

established—one across the southern part of the 

wetland, and one across the northern part—along 

which 3.3-ft2

 (1-m2) plots were established every 33 ft 

(10 m) and marked with 1.5-in. PVC pipe. The height 

of cattail shoots, the cattail density, the percentage of 

plot surface covered by cattails, and the water depth 

were measured at each of 31 plots across the southern 

transect and 26 plots across the northern transect. Only 

20 plots were sampled along the northern transect in 

1996. Samples of above-ground tissues were harvested 

from a 3.3-ft2

 (1-m2) area adjacent to each permanent 

plot, and samples of below-ground tissues were 

collected within these areas from a 1.6-ft2 (0.5-m2

) 

area to a depth of about 12 in. (30 cm). Each sample 

was washed free of sediment and debris, then air-dried 

and weighed, and the biomass per unit area was 

computed. Unusually high water levels and hazardous 

walking conditions in the field necessitated 

modification of the above protocols for biomass 

collection across the northern transect during the 1991 

study. At that time and location, a representative 

sample of above-ground biomass (2 or 3 cattail shoots) 

was collected adjacent to each permanent plot, and the 

rhizomes and roots of these harvested cattails were 

used for the below-ground biomass sample. After 

drying and weighing, the above-ground biomass per 

unit area was computed as the product of the average 

weight per shoot and the number of shoots in the 

adjacent permanent plot. The below-ground biomass 

per unit area was calculated similarly from the average 

rhizome-plus-root weight per shoot. This method of 

calculation was reported to give reliable results for a 

Carex sp. (sedge) wetland in New York (Bernard and 

Gorham, 1978).

Prior to drying, a small subsample of each aboveand below-ground sample was processed for chemical 

analysis. These subsamples were washed in a solution 

of detergent and 0.4 percent hydrochloric acid for 30 

seconds, rinsed twice in distilled water, oven-dried at 

70 ̊C, and ground in a Wiley mill with a 40-mesh 

screen. Samples were composited on the basis of soil 

wetness at the permanent plots, and at least three 

composite samples from each of three “wetness” 

environments (dry, shallow-water, and deep-water 

areas) along each transect were analyzed for metals 

(copper, nickel, chromium, cobalt, molybdenum, zinc, 

aluminum, iron, boron, manganese, and lead) and 

nutrients (nitrogen, phosphorus, potassium, calcium, 

magnesium, and sodium) at the Soil and Plant Testing 

Laboratory in the Soils, Crops and Atmospheric 

Sciences Department at Cornell University, Ithaca, N.Y.

Quality-Assurance and Quality-Control 

Program

Much of the data presented in this report were 

collected and analyzed by the MCEHL, whose 

responsibilities included (1) measurement of stream 

discharge and collection of water samples at the 

streamflow- and water-quality-monitoring stations, 

and (2) analysis of the water samples. A qualityassurance and quality-control (QA/QC) program was 

established to ensure that the data collected by 

MCEHL met USGS standards. QA/QC for discharge 

measurements included (1) periodic instruction of 

MCEHL personnel in USGS measurement techniques; 

(2) monthly review of MCEHL stream-discharge 

measurements; and (3) semiannual discharge 

measurements and inspections of the monitoring sites 

by USGS personnel. The semiannual discharge 

measurements checked the correctness of MCEHL 

measurement techniques and the validity of the stageto-discharge relation that had been developed by the 

USGS for a particular year. 

QA/QC for the water-sampling and analysis 

program included (1) a comparison of constituent 

concentrations measured in depth-integrated crosssectional samples (manual samples) with those 

measured concurrently in samples collected with 

automatic samplers; (2) MCEHL participation in the 

semiannual USGS Standard Reference Water Sample 

program for cooperating analytical laboratories; and 

(3) comparison of results from analyses of split 

samples by MCEHL and the USGS National Water 

Quality Laboratory (NWQL) in Denver, Colo.

Automatic water samplers provided nearly 

continuous water-chemistry data at the wetland inlet 

and outlet. The reliability of these data depends on 

how well constituent concentrations in each sample 

represent the mean concentrations of those 

constituents across the entire flow area. This 

representation was evaluated through a statistical test 

to compare manually collected sample data with the 

automatically collected sample data to determine 

whether the mean of the differences between paired 

data—(manual and automatic)—was significantly 

different from zero (paired t-test). A significant 
13

difference would indicate a systematic bias in the data 

collected by the automatic sampler. Results indicated 

that (1) the concentrations for total suspended solids 

(TSS) and total phosphorus (TP) in the automatically 

collected samples at Blossom Road were significantly 

greater (p-value = 0.0001) than those in manually 

collected samples, and (2) the ammonia-nitrogen 

(NH3) concentrations in automatically collected 

samples at Empire Boulevard were significantly less 

(p-value = 0.0017) than those in manually collected 

samples. No other significant differences (α = 0.05) 

between concentrations obtained with the two 

methods were detected for any other constituent at 

Blossom Road or Empire Boulevard. 

The higher concentrations of TSS and TP in 

automatically collected samples than in the manual 

samples from the Blossom Road site could have 

reflected the location and position of (1) the gage, 

which was at a point where the channel slope and, 

hence, flow velocity were decreasing; (2) the water 

intake, which was in the channel thalweg such that 

it was close to the bottom during medium and highstage flows (repositioning of the intake in the water 

column would have jeopardized collection of lowstage samples); and (3) the manual-samplecollection site for high flows, which was about 

3,500 feet downstream from the automatic-samplecollection site—a distance that, given the decrease 

in gradient, would allow removal of suspended 

sediment and adsorbed chemicals through settling 

or overbank deposition. These discrepancies would 

cause the computed loads and removal efficiencies 

of these constituents calculated for the 

automatically collected samples to be larger than 

those calculated for the manually collected samples. 

The suggested causes for these discrepancies are 

plausible, and except in extreme floods, the 

automatically collected samples might reflect the 

concentrations of these constituents more accurately 

than the manually collected samples.

The higher ammonia concentrations in the 

depth-integrated manually collected samples than in 

the automatically collected samples from the Empire 

Boulevard site could have resulted from the inclusion 

of water with high ammonia concentrations near the 

bottom of the channel (generated by ammonification 

of decomposing organic matter in the bed sediments) 

in the manually collected samples. A similar vertical 

difference in ammonia concentration was reported in a 

wastewater-treatment pond by Davido and Conway 

(1989). The NH3 output load computed from the 

automatically collected samples is significantly larger 

than the computed input load; the negative removal 

efficiency for this constituent indicates that the 

wetland is a source of NH3. The NH3 concentrations 

in the manually collected samples suggest that NH3

output loads should be larger than those computed 

from the concentrations in the automatically collected 

samples. The computed loads could have been 

adjusted to account for this discrepancy, but was not 

done because, even though the magnitude of the 

difference between input and output loads would 

increase, it would not affect the conclusion that the 

wetland is a source of NH3.

MCEHL participated in the semiannual USGS 

Standard Reference Sample (SRS) program, wherein 

reference samples were submitted to participating 

laboratories by USGS for analysis for trace 

constituents, major constituents, and nutrients. The 

analytical results from all participating laboratories 

were transmitted to USGS, and a “most probable 

value” (MPV) was statistically calculated for each 

constituent. MCEHL results were consistently rated 

“satisfactory” to “good” (within 1.50 to 0.51 standard 

deviations of the MPV) for trace elements; and “good” 

to “excellent” (within 1.00 to 0.00 standard deviations 

of the MPV) for major ions, nutrients, and mercury, 

and for analyses of low-ionic strength samples, which 

simulated precipitation. 

An additional check on the analytical accuracy 

of MCEHL included the analyses of samples by both 

MCEHL and NWQL and comparison of the results. 

Samples collected on September 18, 1991, and 

October 20, 1993, were divided into eight equal parts 

(split samples), and four subsamples were analyzed by 

each laboratory for dissolved or total ammonia-plusorganic nitrogen, nitrate-plus-nitrite, and total 

phosphorus. The results of paired t-tests, conducted on 

the analytical data from samples collected at all USGS 

stations in the Monroe County monitoring network to 

identify statistically significant differences between 

the two laboratories for specific constituents, are given 

in Sherwood (1997). Of the samples collected on 

September 18, 1991, only nitrate-plus-nitrite 

concentrations differed significantly between the two 

laboratories, and of the samples collected on October 

20, 1993, only total ammonia-plus-organic nitrogen 

and total phosphorus concentrations showed 

significant differences. P-values associated with these 

tests of significance were not presented in Sherwood 
14 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

(1997). No conclusions from these comparisons have 

been drawn because only two split samples were 

analyzed during the 6-year study period, and the 

results were inconsistent.

Computation of Constituent Loads and 

Removal Efficiency

Monthly and annual constituent loads at the two 

water-quality-monitoring stations were calculated with 

the USGS program, Estimator (G. Baier, T. Cohn, and 

E. Gilroy, U.S. Geological Survey, written commun., 

1995), which is based on a log-linear regression model 

that relates nutrient concentrations to surrogate 

variables of discharge, time (year and decimal-date), 

and season (Cohn and others, 1989; 1992). Nine 

variables were considered for each model: a constant; 

a quadratic fit to the logarithm of discharge (log flow 

and square of log flow); a quadratic fit to time 

(decimal time and square of decimal time); and two 

sinusoidal (first- and second-order Fourier) functions 

to account for the effects of annual seasonality (Cohn 

and others, 1992). Data from the entire period of study 

(October 1990 through September 1996) were used to 

develop the load model for each constituent at each 

sampling site. For a given constituent, if the coefficient 

for a variable was found to be significantly different 

from zero (p-value less than 0.05) for either the input 

or output load models, it was included in both models 

to maintain comparability of the results from both 

models (table 3). The constituent loads were computed 

from continuous water-quality (composited hourly 

samples) and flow data—typically, at least two 

samples were provided per week, but more were 

obtained if a storm occurred. Typically, stormwater 

samples were composited in a similar manner at both 

sites; one sample each for the rising and falling stages 

and one or two samples during the peak. The discharge 

associated with a given water sample was computed as 

the mean of the 15-minute discharges indicated by the 

stage-to-discharge relation at the Blossom Road 

monitoring station and the stage-and-velocity-todischarge relation at the Empire Boulevard site for the 

period covered by the hourly water samples that were 

composited into the analyzed sample. Daily loads 

were computed by the load model from the daily mean 

discharges recorded at each site. From these data, total 

monthly, annual, and period-of-record loads were 

computed for nitrogen and phosphorus compounds, 

chloride, sulfate, and suspended solids. (See 

appendix 2.) The precision of the estimated loads can 

be described in terms of a confidence interval, which is 

based on the estimated mean and the standard error of 

Table 3. Explanatory variables used in regression models developed to compute constituent loads for Irondequoit Creek 

above Blossom Road (wetland inlet) and at Empire Boulevard (wetland outlet), Monroe County, N.Y., 1990-96

[Coefficient for a specified variable was found to be significantly different from zero (p-value less than 0.05) for one or both of the

input- and output-load models. If, for a given constituent, a variable was significant for only one of the load models, 

it was nevertheless used in both models to maintain comparability of the models’ results.] 

Constituent

Explanatory Variable

Constant

Log 

flow

Log flow 

squared

Decimal 

time

Decimal 

time 

squared

Seasonality function (T, time, in years)

Sin(2πT) Cos(2πT) Sin(4πT) Cos(4πT)

Total nitrogen, as N1

1Loads for this constituent were not computed from a regression model.

Ammonia-plus-organic nitrogen, as N XX X X X X X

Ammonia nitrogen, as N XX X X X X X

Organic nitrogen, as N1

Nitrate plus nitrite, as N XXX X X X X X X

Total phosphorus, as P XXX X X X X

Orthophosphate, as P XXX X X X X X X

Total suspended solids XX X X X X

Volatile suspended solids XX X X X X

Nonvolatile suspended solids1

Chloride XXX X X X X X

Sulfate XXX X X
15

prediction calculated by the equation. At a 95-percent 

confidence interval (α = 0.05), the confidence limits 

are the estimated load ±1.96 times the standard error 

of prediction (appendix 2).

Potential problems in calculating loads based on 

regression models include multiply censored waterquality data, logarithm retransformation bias, and lack 

of fit between predicted and observed values. The 

Estimator program handles multiply censored data 

through an adjusted maximum-likelihood estimation 

procedure (Cohn, 1988; 1995). Loads computed from 

the logarithm of constituent concentrations can show 

bias when the loads are transformed back into nonlogarithmic units. This bias, which tends to 

underestimate the loads, is corrected in the Estimator 

program by a minimum-variance unbiased estimator 

(Cohn, 1988; 1995; Cohn and others, 1992). 

Misspecification of a regression model, which is likely 

to result when linear regression is used to describe the 

relation among time-series data, can be indicated by 

serial correlation (non-independence) of the residuals. 

In the Estimator program, serial correlation of 

residuals and the effect of seasonality is minimized by 

inclusion of sinusoidal functions of time (sin2πT, 

cos2πT, sin4πT, cos4πT, where T is time, in years) 

(Cohn and others, 1992). Lack of fit of a regression 

model can be indicated by low coefficients of 

determination and nonnormal distribution and serial 

correlation of the residuals. Cohn and others (1992) 

point out that (1) load estimators based on log-linear 

models, in general, appear to be relatively insensitive 

to violations of the assumptions of linear regression, 

that is, nonnormality and independence of the 

residuals; (2) a minimum variance unbiased estimator, 

in particular, which is based on the assumptions of a 

log-linear model, provides good estimates of loads 

despite these violations; and (3) the variances of 

annual or monthly load estimates based on infrequent 

sampling appear to be well described by log-linear 

model theory. Model validity or goodness of fit was 

evaluated by regression diagnostic statistics—standard 

error of prediction (appendix 2), coefficient of 

determination, and probability plot-correlation 

coefficient as a measure of the normality of the 

residuals—with consideration given to the number of 

total and censored observations included in the 

development of each model (table 4). 

The effectiveness of the wetland in decreasing 

chemical loads can be evaluated in terms of removal 

efficiency—the percentage of an input load that is 

retained in, or exported from, the wetland. Removal 

efficiency for a given constituent was computed as the 

ratio of the difference between input and output load 

to the input load, expressed as a percentage. Monthly 

and annual removal efficiencies were computed for 

each constituent. A positive value indicated a net 

retention of a constituent in the wetland, and a 

negative value indicated the generation of a constituent 

within the wetland (or, possibly, its adjacent drainage 

area) and a net export of a constituent.

Statistical analyses were conducted through 

SAS (SAS Institute, Inc., 1989; 1990). Most of the 

monthly load and removal-efficiency data did not 

show normal distributions; therefore, nonparametric 

tests were used to analyze the data. Statistically 

significant differences between the monthly input and 

output loads were identified by the Wilcoxon signedranks test on the ranked differences between the paired 

(input and output) loads (table 5). This test indicated 

whether the mean of the differences between input and 

output loads was significantly different from zero. 

As a measure of the strength of association 

between variables, Spearman correlation coefficients 

were computed between monthly efficiencies and 

loads, and season and monthly mean discharges and 

water-surface elevations (table 6). A numeric dummy 

variable was used for “season” as follows: (1) October 

through November, when plant senescence occurs, and 

water levels in the wetland drop in response to the 

lowering of Lake Ontario in anticipation of storage 

requirements during spring runoff; (2) December 

through February, when stream discharges and water 

levels are generally low; (3) March and April, when 

stream discharges are usually greatest, and water 

levels begin to rise in the lake and the wetland; and (4) 

May through September, when water levels are high, 

and stream discharges can vary substantially. The 

season variable was used to assess the wetland’s 

water-quality-improvement function that could be 

attributed to nutrient uptake and release by wetland 

vegetation and microbes. The combined 

variables—season and monthly mean discharge and 

water-surface elevation—were used as surrogate 

variables to assess the effect of the duration and depth 

of wetland inundation on wetland processes. 

Frequency of inundation, which could be quantified by 

the number of overbank flows that occurred during a 

given month, was not included in this analysis because 

(1) overbank flows occurred infrequently (from zero to 

four times a year), and (2) the regulated water level in 
16 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

Table 4. Regression statistics for models used to compute constituent loads for Irondequoit Creek above Blossom Road 

(wetland inlet) and at Empire Boulevard (wetland outlet), Monroe County, N.Y., 1990-96

[Dash indicates no data. Locations are shown in fig. 2.] 

Constituent

Number 

of

observations

Number of 

censored 

observations

Coefficient 

of determination1

1Coefficient of determination (R2): the proportion of the total variance in computed loads that is accounted for by regression model.

Residuals 

probability 

plot 

correlation

coefficient2

2Probability-plot correlation coefficient: a measure of the likelihood that the residuals are normally distributed. A value greater than 0.97 

implies that the data are from a population with a normal distribution.

Standard 

error of 

regression3

3Standard error of regression: a measure of the dispersion of the data around the regression line.

Serial 

correlation

of 

residuals4

4Serial correlation of residuals: a measure of the dependence or correlation in time sequence between residuals. Serial correlation 

coefficient ranges from zero (no serial correlation) to 1.00 (strong serial correlation).

Blossom Road

Total nitrogen, as N 5 -- -- -- -- -- --

Ammonia-plus-organic nitrogen, as N 1016 1 0.850 0.988 0.379 0.375

Ammonia nitrogen, as N 985 440 .571 .955 .865 .449

Organic nitrogen, as N 5

5Loads for this constituent were not computed from a regression model.

-- -- -- -- -- --

Nitrate plus nitrite, as N 1007 0 .938 .948 .216 .633

Total phosphorus, as P 1021 0 .745 .988 .665 .299

Orthophosphate, as P 1022 3 .749 .989 .483 .501

Total suspended solids 313 4 .671 .981 .806 .137

Volatile suspended solids 309 21 .648 .986 .725 .228

Nonvolatile suspended solids5 -- -- -- -- -- --

Chloride 1028 0 .931 .973 .192 .582

Sulfate 1015 1 .847 .933 .175 .159

Empire Boulevard

Total nitrogen, as N 5 -- -- -- -- -- --

Ammonia-plus-organic nitrogen, as N 875 0 .883 .993 .298 .510

Ammonia nitrogen, as N 857 100 .502 .986 .715 .580

Organic nitrogen, as N 5 -- -- -- -- -- --

Nitrate plus nitrite, as N 875 0 .957 .992 .188 .625

Total phosphorus, as P 886 0 .837 .980 .439 .421

Orthophosphate, as P 887 1 .866 .981 .321 .536

Total suspended solids 233 3 .745 .984 .623 .228

Volatile suspended solids 232 28 .762 .987 .493 .293

Nonvolatile suspended solids5 -- -- -- -- -- --

Chloride 890 0 .933 .977 .196 .599

Sulfate 874 0 .877 .978 .160 .274

this system would have obscured any short-term 

effects from overbank flows. Correlation coefficients 

between monthly removal efficiencies, their respective 

input and output loads, and monthly mean discharges 

were computed, but some amount of artificial or 

spurious correlation between these variables was 

expected because the loads were based on discharges, 

and removal efficiencies were based on loads. 
17

EFFECTS OF WETLAND ON WATER 

QUALITY

Chemical concentrations in a stream are affected 

by the volume of flow at the time the sample is 

collected. Concentrations (mass per volume) of 

constituents in the dissolved phase generally decrease 

through dilution as flow increases, whereas the loads 

(total mass) of these constituents generally increase 

during high flows. Dissolved constituents in the 

Ellison Park wetland, such as ammonia nitrogen 

(NH3), generally followed this pattern. The range of 

ammonia-nitrogen concentrations, and the maximum 

concentrations (fig. 5A), were greater during low 

flows (0.01 to 0.66 mg/L) than during high flows (0.01 

to 0.09 mg/L), and, similarly, the maximum 

concentrations of orthophosphate were greater during 

low flows (0.12 mg/L) than during high flows 

(0.03 mg/L). Concentrations of constituents in the 

particulate phase generally increase with increasing 

flow, as do their corresponding loads, when the 

sediment and organic matter to which these 

constituents adsorb is washed into the stream by 

overland flow or resuspended from the channel bottom 

by turbulence. The concentration-to-flow relations for 

constituents in the Ellison Park wetland that are 

associated with particulate matter, such as total 

phosphorus (TP; fig. 5B), show discrepancies, 

however. The concentrations of TP in most low-flow 

samples clustered between 0 and 0.4 mg/L but in some 

samples were as high as 1.5 mg/L. Generally, TP 

concentrations increased with increasing discharge to 

the 700- to 900-ft3

/s flow range, at least at the Blossom 

Road (inflow) site, then decreased as discharge 

increased further. These apparent discrepancies might 

be explained by (1) the time of sample collection in 

relation to the peak discharge for a given storm, and 

(2) the duration of high flows prior to collection of a 

sample. Despite these discrepancies in the 

concentration-to-flow relation for particulate 

constituents, the loads of these chemicals were directly 

related to discharge (table 6). 

The effectiveness of any wetland in decreasing 

chemical loads depends on the balance between 

chemical-removal and chemical-generation processes 

because this balance determines whether a wetland 

acts as a sink or a source of a given constituent at a 

given time. In general, the Ellison Park wetland had 

little effect on the surface-water concentrations and 

loads of dissolved constituents, except ammonia 

nitrogen and orthophosphate, which were generated by 

Table 5. Statistics (p values) related to tests of significant difference between monthly constituent loads computed 

for Irondequoit Creek above Blossom Road (wetland inlet) and at Empire Boulevard (wetland outlet), Monroe 

County, N.Y., 1990-96

[Statistics are based on differences between monthly paired data; that is, input (Blossom Road) load minus output (Empire 

Boulevard) load. Dash indicates test is inappropriate for nonnormally distributed data, or that no conclusion can be stated.] 

Constituent

Shapiro-Wilk 

test of 

normality

(p-value)

Tests of significance

(p-value)

Significant 

difference

Location 

of greater 

load

Paireddifference 

t-test

Wilcoxon 

Signed ranks

test

Total nitrogen, as N 0.0001 -- 0.0028 yes inflow

Ammonia-plus-organic nitrogen, as N .0001 -- .1005 no --

Ammonia nitrogen, as N .1358 .0001 .0001 yes outflow

Organic nitrogen, as N .0001 -- .0006 yes inflow

Nitrate plus nitrite, as N .0030 -- .0163 yes inflow

Total phosphorus, as P .0001 -- .0001 yes inflow

Orthophosphate, as P .0001 -- .0001 yes outflow

Total suspended solids .0001 -- .0001 yes inflow

Volatile suspended solids .0001 -- .0001 yes inflow

Nonvolatile suspended solids .0001 -- .0001 yes inflow

Chloride .0019 -- .0001 yes outflow

Sulfate .0692 .0024 .0007 yes inflow
18 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

Table 6. Spearman correlation coefficients between constituent loads and removal efficiencies and four 

variables, Ellison Park wetland, Monroe County, N.Y., 1990-96

Constituent

Variables

Monthly

mean discharge1

1

 Measured at Irondequoit above Blossom Road (wetland inlet)).

Season2

2

 Season was defined by a numeric value: 1 = October-November,; 2 = December-February, 3 = March-April, and 4 = May-September.

Monthly mean 

water-surface

elevation

Removal

 efficiency 

LOADS

Total nitrogen, input 0.98 -0.20 0.25 0.30

Total nitrogen, output .98 -.27 .16 .18

Ammonia-plus-organic nitrogen, input .96 -.13 .32 .67

Ammonia-plus-organic nitrogen, output .96 -.17 .27 .57

Ammonia nitrogen, input .90 -.18 .25 .71

Ammonia nitrogen, output .88 -.17 .17 .13

Organic nitrogen, input .96 -.13 .32 .59

Organic nitrogen, output .95 -.17 .27 .46

Nitrate-plus-nitrite nitrogen, input .96 -.24 .19 -.20

Nitrate-plus-nitrite nitrogen, output .96 -.33 .07 -.34

Total phosphorus, input .87 .06 .41 .55

Total phosphorus, output .79 .12 .47 .30

Orthophosphate, input .79 -.06 .27 .25

Orthophosphate, output .78 .00 .33 .04

Total suspended solids, input .93 .00 .38 .35

Total suspended solids, output .89 -.02 .36 .12

Volatile suspended solids, input .94 -.05 .34 .41

Volatile suspended solids, output .92 -.17 .24 .12

Nonvolatile suspended solids, input .93 .01 .38 .33

Nonvolatile suspended solids, output .88 .00 .38 .10

Chloride, input .91 -.34 .06 -.04

Chloride, output .92 -.36 .01 -.13

Sulfate, input .99 -.19 .25 -.05

Sulfate, output .99 -.22 .19 -.20

REMOVAL EFFICIENCIES

Total nitrogen .31 .47 .59 1.00

Ammonia-plus-organic nitrogen .64 .11 .44 1.00

Ammonia nitrogen .45 -.10 .19 1.00

Organic nitrogen .59 .13 .42 1.00

Nitrate-plus-nitrite nitrogen -.18 .67 .59 1.00

Total phosphorus .54 -.11 .05 1.00

Orthophosphate .15 -.18 -.08 1.00

Total suspended solids .30 .02 .07 1.00

Volatile suspended solids .32 .31 .30 1.00

Nonvolatile suspended solids .29 -.02 .03 1.00

Chloride .14 .19 .32 1.00

Sulfate -.06 .24 .23 1.00
19

0 200 400 600 800 1,000 1,200 1,400 1,600 1,800

DISCHARGE, IN CUBIC FEET PER SECOND

0

2.5

0.5

1.0

1.5

2.0

CONCENTRATION, IN MILLIGRAMS PER LITER

Blossom Road (inflow)

Empire Boulevard (outflow)

0 200 400 600 800 1,000 1,200 1,400 1,600 1,800

0.8

0

0.2

0.4

0.6

CONCENTRATION, IN MILLIGRAMS PER LITER

Blossom Road (inflow)

Empire Boulevard (outflow)

A. AMMONIA NITROGEN

B. TOTAL PHOSPHORUS

wetland processes and exported from the wetland in 

quantities larger than those which entered the wetland. 

Conversely, the wetland facilitated a substantial 

decrease in particulate constituents, such as suspended 

solids and total phosphorus, through sedimentation 

and vegetative filtration.

Constituent Loads and Removal 

Efficiencies

Two factors that could have affected the 

calculated constituent loads and removal efficiencies 

for the Ellison Park wetland were chemical inputs 

from atmospheric deposition and ground water. 

Atmospheric deposition was collected monthly in the 

northern part of the wetland, about 1,700 ft south of 

Empire Boulevard (fig. 2). Precipitation-quality data 

are given in Coon (1997) or in the annual USGS 

water-resources-data reports for western New York 

State, for example, Hornlein and others (1997). 

Kappel and others (1986) noted that atmospheric 

deposition in the Irondequoit Creek basin is a 

significant source of chemicals and, except for 

chloride, can make substantial contributions to 

chemical loads in the creek. Atmospheric-deposition 

sampling has inherent uncertainties that are related to 

Figure 5. Concentration of (A) a dissolved constituent (ammonia nitrogen), and (B) a particulate constituent (total 

phosphorus) as a function of discharge in Irondequoit Creek above Blossom Road and at Empire Boulevard, Monroe 

County, N.Y., 1990-96
20 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

possible contamination by wildlife (primarily birds), 

areal variability in precipitation and dryfall, and a lack 

of information on the interactions and fate of 

chemicals after deposition; therefore, Kappel and 

others (1986) cautioned against using chemical 

contributions from atmospheric sources to compute 

seasonal rates of deposition, accumulation, or washoff 

to streams. Furthermore, atmospheric deposition that 

falls directly on freshwater marshes dominated by 

surface-water inflow is a relatively small source of 

nutrients (Mitsch and Gosselink, 1986). The Ellison 

Park wetland is surface-water dominated, and the 

difference in drainage area between the inflowsampling site above Blossom Road (142 mi2

) and the 

outflow-sampling site at Empire Boulevard (151 mi2

) 

is only 6 percent; therefore, chemical inputs from 

atmospheric deposition were considered too small to 

affect the results of this study.

Ground-water levels and chemical quality in 

Ellison Park were measured at nine observation wells 

in the vicinity of Browncroft Boulevard and Blossom 

Road (fig. 2) (not in the cattail-covered area of the 

wetland). Ground-water levels and ground-waterquality data are given in Coon (1997) or in the annual 

USGS water-resources-data reports for western New 

York State, for example, Hornlein and others (1997). 

The Ellison Park wetland is a regional and local 

ground-water-discharge area (Yager and others, 

1985), but no studies to date have been conducted to 

map ground-water movement in the wetland, measure 

ground-water-discharge rates, define the interactions 

between ground water, surface water, and 

atmospheric deposition, or to compute chemical loads 

that enter the wetland from ground water. Groundwater contributions to nutrient loads in freshwater 

wetlands dominated by surface-water flow are 

reported to be relatively small (Mitsch and Gosselink, 

1986); therefore, surface-water output loads from the 

Ellison Park wetland were not adjusted for inputs 

from this source.

Monthly and annual surface-water loads of 

selected constituents at the Ellison Park wetland 

inflow and outflow monitoring sites (Irondequoit 

Creek above Blossom Road and at Empire Boulevard, 

respectively) are presented in appendix 2; the 

monthly and annual removal efficiencies for each 

constituent are given in appendix 3. The average 

annual input and output loads, and the annual and 

period-of-study removal efficiencies for each of these 

constituents are summarized in table 7. The following 

sections describe the effect of the wetland on loads of 

nitrogen, phosphorus, suspended solids, chloride, and 

sulfate, and the wetland’s removal efficiency for each. 

Note that:

1. The method used to compute loads is an 

estimation technique, where results have been shown 

to compare reasonably well with observed loads 

(Cohn and others, 1992).

2. Loads and removal efficiencies are based on 

annual and period-of-study results, and tests of 

significance are based on the differences between the 

monthly input and output loads.

3. Removal efficiencies are computed in relation 

to the input loads; therefore, large absolute values 

must be analyzed in relation to the constituent mass 

that is entering the wetland. Large monthly 

fluctuations in removal efficiencies, and large negative 

values during low-flow periods, which suggest a net 

exportation of a constituent, can be misleading. The 

monthly removal efficiencies were calculated to 

indicate seasonal trends (if present) and long-term 

trends in the capability of the wetland to improve 

water quality.

Nitrogen

The mechanisms by which nitrogen can enter a 

wetland include surface-water or ground-water inflow, 

atmospheric deposition, and nitrogen fixation—the 

conversion of nitrogen gas in the atmosphere to 

ammonia (Kadlec and Knight, 1996). Nitrogen can be 

stored in live or standing-dead plants, detritus, 

microbes, wildlife, soils, and in the water column. The 

amount of nitrogen storage in vegetation changes with 

plant species, plant part, above- or below-ground 

tissue, and season (Kadlec and Knight, 1996). 

Ammonia can be removed from solution through 

cation-exchange adsorption reactions with detritus and 

inorganic sediments (Kadlec and Knight, 1996). 

Burial of organic matter results in long-term storage of 

nitrogen. Nitrogen can be transformed within a 

wetland by the processes of (1) ammonification, or 

mineralization of organic nitrogen to ammonia —the 

initial step in the microbial breakdown of organic 

tissues containing amino acids; (2) nitrification—the 

conversion of ammonia to nitrate under aerobic 

conditions; (3) denitrification—the reduction of nitrate 

or nitrite to nitrogen gas under anoxic conditions; and 

(4) nitrogen assimilation—the conversion of inorganic 

nitrogen forms to organic compounds for cell and 

tissue growth (Kadlec and Knight, 1996). Most of 
21

these processes are microbially mediated and, 

therefore, temperature dependent—that is, in northern 

wetlands, these processes proceed at faster rates 

during the summer than during the winter. Nitrogenreleasing processes include decomposition of organic 

matter, leaching, denitrification, and ammonia 

desorption (Kadlec and Knight, 1996).

Total Nitrogen

Total nitrogen (TN) consists of the reduced 

forms of nitrogen (ammonia and organic nitrogen) 

and the oxidized forms of nitrogen (nitrate and 

nitrite). The 6-year average input load of TN in the 

Ellison Park wetland was 275 tons, whereas the 

average output load was 263 tons (table 7). Monthly 

Table 7. Concentrations and average annual input and output loads, and removal efficiency, for selected constituents, 

Ellison Park wetland, Monroe County, N.Y.,1990-96 

[Inflow and outflow locations are shown in fig. 2. Dash indicates concentration not measured.] 

A. Inflow and outflow concentrations (in milligrams per liter) and average annual load (in tons)

Constituent

Inflow concentration Outflow concentration Average annual load 

Interquartile

range Median

Interquartile

range Median

Input 

(Blossom Rd.)

Output 

(Empire Blvd.)

Total nitrogen -- -- -- -- 275 263

Ammonia-plus-organic nitrogen 0.99 - 0.58 0.77 0.98 - 0.61 0.78 126 118

Ammonia nitrogen 0.02 - 0.01 .01 0.05 - 0.02 .03 2.59 4.76

Organic nitrogen -- -- -- -- 124 114

Nitrate plus nitrite 1.2 - 0.79 .96 1.2 - 0.73 .885 149 145

Total phosphorus 0.17 - 0.055 .11 0.16 - 0.06 .10 26.2 19.0

Orthophosphate 0.016 - 0.007 .011 0.023 - 0.01 .016 1.69 2.33

Total suspended solids 244 - 95 139 152 - 73 102 28,500 15,200

Volatile suspended solids 30.5 - 15 21 21 - 12 16 3,540 2,080

Nonvolatile suspended solids -- -- -- -- 24,900 13,100

Chloride 140 - 95 110 140 - 100 120 16,800 17,500

Sulfate 180 - 110 140 170 - 110 140 16,000 15,700

B. Removal efficiency, as percentage of input load, by water year1

1Water year is the period from October of one year to September of the following year.

Constituent 1991 1992 1993 1994 1995 1996 Study period

Total nitrogen 9.6 -1.8 4.6 0.3 2.7 7.6 4.3

Ammonia-plus-organic nitrogen 13.5 1.2 8.1 0 -3.2 8.7 6.1

Ammonia nitrogen 15.3 -42.2 -61.8 -137 -262 -315 - 84.0

Organic nitrogen 13.4 2.2 9.5 2.3 1.5 13.4 8.0

Nitrate plus nitrite 5.9 -5.0 1.3 .1 6.4 6.8 2.7

Total phosphorus 14.5 17.1 33.0 26.0 21.1 49.0 27.6

Orthophosphate -34.1 -67.1 -45.5 -46.0 -28.8 -10.5 - 38.1

Total suspended solids 31.9 40.4 51.3 51.1 49.4 58.6 46.7

Volatile suspended solids 28.1 34.6 43.5 43.8 42.1 55.4 41.0

Nonvolatile suspended solids 32.4 41.2 52.4 52.2 50.7 59.0 47.5

Chloride 3.4 -10.6 -3.7 -6.8 -3.2 -3.8 - 3.9

Sulfate 7.4 -2.4 1.1 -.9 3.1 3.8 2.0
22 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

1991 1992 1993 1994 1995 1996

0

100

20

40

60

80

MONTHLY LOAD, IN TONS

Blossom Road (input load)

Empire Boulevard (output load)

TOTAL NITROGEN, AS N

1991 1992 1993 1994 1995 1996

-40

40

-20

0

20

REMOVAL EFFICIENCY, AS PERCENTAGE OF INPUT LOAD

A. MONTHLY LOAD

B. REMOVAL EFFICIENCY

input and output loads were similar (fig. 6), but the 

differences were statistically significant (p-value = 

0.0028; table 5) and indicated that the wetland 

facilitated a small net removal of TN. Annual removal 

efficiencies for TN ranged from 9.6 to -1.8 percent 

and averaged 4.3 percent.

Ammonia plus Organic Nitrogen

Median concentrations of ammonia-plus-organic 

nitrogen (TKN) at the inflow and outflow were 0.77 

and 0.78 mg/L, respectively, and the interquartile 

ranges at these two sites also were similar (table 7). 

Maximum TKN inflow concentrations were often 

twice as high as the corresponding outflow 

concentrations, indicating that peak TKN 

concentrations decreased within the wetland. The 

1990-96 plot of TKN concentrations (fig. 7A) indicates 

a seasonal pattern of high TKN concentrations during 

the summer and low concentrations during the winter, 

at least during 1991-94. The average estimated annual 

input load of TKN was 126 tons, and the average 

output load was 118 tons (table 7). Annual removal 

efficiencies ranged from -3.2 to 13.5 percent and 

averaged 6.1 percent for the study period, but the 

monthly input and output loads (fig. 7B) did not differ 

Figure 6. Monthly load and wetland’s removal efficiency for total nitrogen, Ellison Park wetland, Monroe County, 

N.Y., 1990-96
23

significantly (p-value = 0.1005; table 5). Input loads 

generally exceeded output loads during high-flow 

periods, but the two were similar during low-flow 

periods (fig. 7).

Ammonia Nitrogen

Concentrations of ammonia (NH3) at the inflow 

(fig. 8A) were typically lower than outflow 

concentrations, and the median values and 

interquartile ranges for the inflow also were lower than 

those for the outflow (table 7). No seasonal pattern in 

NH3 concentrations is apparent (fig. 8A). Output loads 

of NH3, which constituted 4 percent of the TKN 

output loads and 1.8 percent of the TN loads exiting 

the Ellison Park wetland, were consistently greater 

than the input loads (fig. 8B). The average estimated 

annual input load of NH3 was 2.59 tons (2 percent of 

the annual TKN input load and 0.9 percent of the TN 

load); the average output load was 4.76 tons (table 7). 

Annual removal efficiencies ranged from -315 to 15.3 

percent and averaged -84.0 percent for the study 

period (fig. 8C). The significant difference (p-value = 

0.0001) between monthly input and output loads 

(table 5) indicated that the Ellison Park wetland was a 

source of NH3. The general downward trend of the 

monthly removal efficiencies (fig. 8C) indicated that 

generation of NH3 in the wetland increased through 

the study period. The increase in NH3 loads was 

obscured in the TKN data by the large loads of Org-N, 

which were 2 orders of magnitude larger than the NH3

loads. These results suggest that the increase in NH3

loads was caused by transformation processes within 

the wetland, such as ammonification and dissimilatory 

nitrate reduction, and diffusion of NH3 from anaerobic 

sediments. A net increase in NH3 loads within the 

wetland can be expected because the rate of 

ammonification exceeds the rate of nitrification 

(Kadlec and Knight, 1996). Rates of NH3 production 

would be expected to be higher under flooded 

(anaerobic) conditions than under low-water 

conditions, but coefficients of correlation of NH3 loads 

and removal efficiencies with monthly mean water 

levels (table 6) were less than 0.26 and, thus, do not 

support this interpretation. 

Organic Nitrogen

Organic nitrogen (Org-N) made up 98 percent 

of the TKN input load; therefore, monthly Org-N 

loads showed a temporal variation similar to that of 

TKN during the study period, and the monthly output 

loads were similar to or slightly less than the 

monthly input loads. Removal efficiencies for Org-N 

were slightly higher than those for TKN; annual 

removal efficiency ranged from 1.5 to 13.4 percent 

and averaged 8.0 percent for the study period 

(table 7). The monthly Org-N input loads and output 

loads differed significantly (p-value = 0.0006; 

table 5). The significant difference for Org-N loads, 

but not TKN loads, is attributed to the generation of 

NH3 in the wetland, which offset the slight decrease 

in Org-N loads.

Nitrate plus Nitrite Nitrogen

Concentrations of nitrate-plus-nitrite nitrogen 

(NOx) fell within the interquartile range of 1.2 to 

0.73 mg/L at both sites; the outflow median 

concentration was slightly less than the inflow median 

concentration (table 7). A strong seasonal pattern in 

NOx concentrations is evident in fig. 9A; NOx

concentrations at both monitoring sites increased 

during late fall and early winter, attained peak values 

during winter and spring, and decreased through the 

summer. This pattern could result from denitrification 

during the summer, but this water-quality 

improvement did not occur entirely in the wetland 

because the inflow and outflow concentrations were 

comparable. The average estimated annual input load 

of NOx was 149 tons and the average output load was 

145 tons (table 7). Monthly input loads were similar to 

monthly output loads (fig. 9), but the difference is 

significant (p-value = 0.0163) (table 5). The annual 

removal efficiencies for NOx ranged from -5.0 to 6.8 

percent and averaged 2.7 percent (table 7) for the 

study period. 

Nitrogen loads entering and leaving the wetland 

were directly related to discharge (table 6) and were 

highest during high-flow periods. Coefficients of 

correlation between discharge and loads of all forms 

of nitrogen were equal to or greater than 0.90, except 

for the output loads of ammonia, whose coefficient of 

correlation with discharge was 0.88 (table 6). Removal 

efficiencies for all nitrogen constituents (except NOx), 

in contrast, appeared not to be correlated with 

discharge, season, or water level (table 6). The 

possible exception of NOx, had a fairly strong 

association with season (0.67) and water level (0.59). 

Graphical analyses of nitrogen-removal efficiencies 

indicate differing seasonal trends: (1) Although NOx

input loads were generally similar to output loads 

(fig. 9B), the removal efficiencies (fig. 9C) were low 
24 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

1991 1992 1993 1994 1995 1996

0

6

1

2

3

4

5

CONCENTRATION, IN MILLIGRAMS PER LITER

Blossom Road (inflow)

Empire Boulevard (outflow)

1991 1992 1993 1994 1995 1996

0

50

10

20

30

40

MONTHLY LOAD, IN TONS

Blossom Road (input load)

Empire Boulevard (output load)

AMMONIA PLUS ORGANIC NITROGEN, AS N

1991 1992 1993 1994 1995 1996

-40

40

-20

0

20

REMOVAL EFFICIENCY, AS PERCENTAGE OF INPUT LOAD

A. CONCENTRATION

B. MONTHLY LOAD

C. REMOVAL EFFICIENCY

Figure 7. Concentration, monthly load, and removal efficiency of ammonia-plus-organic nitrogen, Ellison Park wetland, 

Monroe County, N.Y., 1990-96
25

1991 1992 1993 1994 1995 1996

0.25

0

0.05

0.10

0.15

0.20

CONCENTRATION, IN MILLIGRAMS PER LITER

Blossom Road (inflow)

Empire Boulevard (outflow)

1991 1992 1993 1994 1995 1996 0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

MONTHLY LOAD, IN TONS

Blossom Road (input load)

Empire Boulevard (output load)

AMMONIA NITROGEN, AS N

1991 1992 1993 1994 1995 1996

200

-600

-400

-200

0

REMOVAL EFFICIENCY, IN PERCENT OF INPUT LOAD

B. MONTHLY LOAD

C. REMOVAL EFFICIENCY

A. CONCENTRATION

Figure 8. Concentration, monthly load, and wetland’s removal efficiency for ammonia nitrogen, Ellison Park wetland, 

Monroe County, N.Y., 1990-96
26 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

1991 1992 1993 1994 1995 1996

0

2.5

0.5

1.0

1.5

2.0

CONCENTRATION, IN MILLIGRAMS PER LITER

Blossom Road (inflow)

Empire Boulevard (outflow)

1991 1992 1993 1994 1995 1996

0

40

10

20

30

MONTHLY LOAD, IN TONS

Blossom Road (input load)

Empire Boulevard (output load)

NITRATE PLUS NITRITE, AS N

1991 1992 1993 1994 1995 1996

-40

40

-20

0

20

REMOVAL EFFICIENCY, IN PERCENT OF INPUT LOAD

C. REMOVAL EFFICIENCY

B. MONTHLY LOAD

A. CONCENTRATION

Figure 9. Concentration, monthly load, and wetland’s removal efficiency for nitrate-plus-nitrite nitrogen, Ellison Park 

wetland, Monroe County, N.Y., 1990-96
27

or negative during the fall and winter and high during 

the spring and summer. (2) The exportation of NH3

decreased during late winter and spring (fig. 8C), 

presumably from the winter decrease in biological 

activity and an increase in aerobic conditions resulting 

from low regional water levels. The generation of NH3

increased during the other seasons, presumably as a 

result of increased biological activity, anaerobic 

conditions caused by high regional water levels in 

summer, and plant senescence in fall. TKN input loads 

were similar to the output loads (fig. 7B), and the 

removal efficiencies (fig. 7C) fluctuated around zero 

and formed no noticeable seasonal trend.

An additional observation is that the input loads 

for NH3 appeared to decrease after 1993 (fig. 8B), 

while output loads remained about the same. The net 

result was an increasing trend in the percentage of 

NH3 that was exported from the wetland. This trend 

indicates an increase in the rate of transformation of 

Org-N to NH3 or in the rate of reduction of NOx to 

NH3, if inputs of NH3 from external sources remained 

constant. This trend in NH3 export increased 

noticeably around 1993-94 (figs. 8B, 8C), the period 

of increased flow into the southeastern part of the 

southern wetland area after the flow-diversion 

modifications to the Millrace and, thus, could result 

from the increased residence time and prolonged 

contact between stormwaters and wetland biota, and 

the subsequent increase in the rate of mineralization of 

organic nitrogen. 

Phosphorus

Surface inflow and its associated suspendedsediment load (primarily clay) is the primary source of 

phosphorus to a wetland; atmospheric contributions 

are considered insignificant (Kadlec and Knight, 

1996). Phosphorus-storage mechanisms within a 

wetland include assimilation by plants, microbial 

utilization, deposition of particulate phosphorus 

through sedimentation, accretion of biomass in soils, 

sorbtion to clay and organic particles, and formation of 

insoluble precipitates with metal cations (iron and 

aluminum in acidic soils, or calcium and magnesium 

in alkaline soils) (Kadlec and Knight, 1996; Hickok, 

1978; Mitsch and Gosselink, 1986). Phosphorusreleasing processes include oxidation (or 

decomposition) of organic matter, desorption from 

clay and organic particles, translocation from soils to 

above-ground plant tissue, followed by leaching and 

decay of organic matter, and, in reduced environments, 

solubilization of iron minerals and subsequent release 

of phosphorus coprecipitates (Kadlec and Knight, 

1996; Gehrels and Mulamoottil, 1989).

Total Phosphorus

Median concentrations of total phosphorus (TP) 

at the inflow and outflow were 0.11 and 0.10 mg/L, 

respectively, and the interquartile ranges for both sites 

were similar (table 7). Maximum TP concentrations at 

the inflow were higher, sometimes an order of 

magnitude higher, than the corresponding 

concentrations at the outflow, indicating that peak TP 

concentrations decreased within the wetland. A time 

plot of TP concentrations (fig. 10A) suggests a slight 

seasonal pattern of high TP concentrations during the 

summer and low concentrations during the winter, 

excepting periods of peak inflows. The average 

estimated annual input load of TP during the study 

period was 26.2 tons; the average output load was 

19.0 tons (table 7). The monthly input and output 

loads differed significantly (p-value = 0.0001; table 5). 

The wetland was effective in decreasing TP loads; 

annual TP-removal efficiency ranged from 14.5 to 

49.0 percent and averaged 27.6 percent for the study 

period (table 7). Inflow TP loads were correlated with 

discharge (Spearman correlation coefficient, 0.87; 

table 6); they increased in late winter and spring, the 

period of rapid melting of accumulated snow (“first 

flush”), and during heavy storms and periods of high 

runoff during the summer and fall (fig. 10). Unusually 

large loads of TP (53 percent of the 1992 annual load) 

entered the wetland during July and August 1992, 

when three overbank flows occurred, and during 

March and April 1993, when high flows that included 

the period-of-record maximum discharge on 

Irondequoit Creek, carried 58 percent of the 1993 

annual TP load into the wetland. 

Orthophosphate

Concentrations of orthophosphate (PO4, the 

dissolved phase of phosphorus) at the inflow were 

typically lower than at the outflow, as were the median 

values and interquartile ranges (table 7). A seasonal 

pattern, although inconsistent, is apparent in the time 

plot in figure 11A, which indicates that, during most 

years, high PO4 concentrations occurred during the 

summer and fall. The presence of this pattern at both 

monitoring sites indicates that it cannot result solely 

from processes within the wetland; superimposed 

upon this pattern, however, are three summer (1991, 
28 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

1991 1992 1993 1994 1995 1996

0

2.5

0.5

1.0

1.5

2.0

CONCENTRATION, IN MILLIGRAMS PER LITER

Blossom Road (inflow)

Empire Boulevard (outflow)

1991 1992 1993 1994 1995 1996

0

14

2

4

6

8

10

12

MONTHLY LOAD, IN TONS

Blossom Road (input load)

Empire Boulevard (output load)

TOTAL PHOSPHORUS, AS P

1991 1992 1993 1994 1995 1996

-60

80

-40

-20

0

20

40

60

REMOVAL EFFICIENCY, IN PERCENT OF INPUT LOAD

B. MONTHLY LOAD

C. REMOVAL EFFICIENCY

A. CONCENTRATION

Figure 10. Concentration, monthly load, and wetland’s removal efficiency for total phosphorus, Ellison Park wetland, 

Monroe County, N.Y., 1990-96
29

1993, and 1995) periods of elevated PO4

concentrations that occur only at the outlet (fig. 11A) 

and, therefore, can be attributed to wetland processes. 

The average estimated annual input load of PO4 was 

1.69 tons (6.5 percent of the annual TP input load); the 

average output load was 2.33 tons (12.3 percent of the 

TP output load) (table 7). The monthly input and 

output loads differed significantly (p-value = 0.0001; 

table 5). The annual removal efficiency ranged from 

-10.5 to -67.1 percent and averaged -38.1 percent for 

the study period (table 7). The generation of PO4 is 

attributed to the release processes mentioned above. 

Similar seasonal patterns have been documented by 

Klopatek (1978) and Kadlec and Knight (1996). The 

peak loads of PO4 coincided with those for total 

phosphorus (figs. 10 and 11); that is, peak loads 

occurred during high-flow periods, but the export of 

PO4 occurred throughout the study period. 

High TP removal efficiency was associated with 

peak flows, and low removal efficiency was evident 

during summer low-flow periods (fig. 10C), although 

the correlation between removal efficiency and inflow 

loads of total phosphorus was weak (Spearman 

correlation coefficient, 0.55; table 6). The removal 

efficiency for phosphorus appears to have increased 

around mid-1994 (fig. 11C), probably as a result of the 

1994 Millrace modifications that increased flow into 

the southeastern backwater section of the wetland. 

Neither water depth nor duration of inundation were 

related in a consistent manner to phosphorus-removal 

efficiency when evaluated separately from other 

factors (table 6). When evaluated in conjunction with 

inflow loading rates, hovever, they appeared to 

correlate with phosphorus removal, as evidenced by 

high removal efficiency during the prolonged periods 

of inundation in the spring of 1991 and 1993 (figs. 4 

and 10C). The correlation between water depth and 

removal efficiency was probably obscured by the 

effects of other phosphorus-cycling mechanisms 

within the wetland. 

Phosphorus uptake and retention in temperateclimate marshes, such as the Ellison Park wetland, 

generally increase during the growing season and 

decrease during the senescence period; but exceptions 

have been observed. For example, a 1-year 

phosphorus-budget study of a Typha marsh in Ontario, 

Canada, by Gehrels and Mulamoottil (1989) found 

that seasonal PO4 outputs approximately equaled 

inputs during winter, spring, and summer but were 60 

percent greater than inputs during the fall. Seasonal 

trends reported by Kadlec and Knight (1996) at five 

Canadian cattail-monocultural (Typha latifolia) 

constructed wetlands indicated that (1) large decreases 

in TP loads resulted from assimilation by biota during 

the spring growing season and from translocation of 

nutrients to the rhizomes during the fall; (2) TP 

removal decreased during the summer, probably as a 

result of phosphorus-releasing processes (leaching and 

decomposition of organic matter), which generated 

more phosphorus than was being retained by 

phosphorus-assimilation processes; and (3) midwinter 

decreases in phosphorus removal coincided with a 

decrease in biological activity. These processes could 

explain some of the seasonal variations in the TP and 

PO4 removal efficiencies in the Ellison Park wetland, 

but the pattern was not consistent from year to year. 

The summer release of phosphorus by leaching and 

decomposition of organic matter could be the reason 

for the non-flow-related decrease in removal efficiency 

(increase in exportation) of PO4 during the summer of 

1992 (fig. 11C).

Suspended Solids

The primary source of suspended solids in the 

Irondequoit Creek basin is sediment eroded from 

stream channels and upland soils. Construction 

activities and development have disrupted the soil 

protection afforded by natural vegetation and have 

increased the amount of sediment-laden runoff. The 

increase in impervious surface area (buildings, roads, 

and parking lots) has increased the volume of storm 

runoff and thereby increased peak discharges for a 

given rainfall. This, in turn, has altered the hydrologic 

equilibrium of Irondequoit Creek and probably has 

aggravated erosion and sediment aggradation. Even if 

upland erosion and runoff volumes were decreased, 

channel storage of silt and clay particles from 

construction and development would be a long-term 

source of sediment to the wetland (Harbison, 1974). A 

substantial point source of sediment is a steep bluff 

composed of fine-grained glacial material about 3 mi 

upstream from the wetland. Young and Burton (1993) 

estimated the erosion rate of this bluff and concluded 

that the volume of sediment derived from it was equal 

to about 50 percent of the total sediment load delivered 

to the wetland.

Median concentrations of total suspended solids 

(TSS) at the inflow and outflow were 139 and 

102 mg/L, respectively. Median concentrations of 

volatile suspended solids (VSS), the organic 
30 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

1991 1992 1993 1994 1995 1996

0

0.16

0.02

0.04

0.06

0.08

0.10

0.12

0.14

CONCENTRATION, IN MILLIGRAMS PER LITER

Blossom Road (inflow)

Empire Boulevard (outflow)

1991 1992 1993 1994 1995 1996

0

1.2

0.2

0.4

0.6

0.8

1.0

MONTHLY LOAD, IN TONS

Blossom Road (input load)

Empire Boulevard (output load)

ORTHOPHOSPHATE, AS P

1991 1992 1993 1994 1995 1996

-100

0

-80

-60

-40

-20

REMOVAL EFFICIENCY, IN PERCENT OF INPUT LOAD

B. MONTHLY LOAD

C. REMOVAL EFFICIENCY

A. CONCENTRATION

Figure 11. Concentration, monthly load, and wetland’s removal efficiency for orthophosphate, Ellison Park wetland, Monroe 

County, N.Y., 1990-96
31

component of TSS, at the inflow and outflow were 21 

and 16 mg/L, respectively. The interquartile ranges for 

both constituents at the inflow exceeded those at the 

outflow (table 7); thus, the wetland was a sink for 

suspended solids. The amounts of TSS entering the 

wetland during the study were large (fig. 12B); the 

average estimated annual input load was 28,500 tons, 

and the average output load was 15,200 tons (table 7). 

This difference, which is statistically significant (pvalue = 0.0001; table 5), resulted in annual removal 

efficiencies that ranged from 31.9 to 58.6 percent and 

averaged 46.7 percent for the study period (table 7, 

fig. 12C). Volatile suspended solids constituted 12 to 

14 percent of TSS; the average estimated annual input 

load of VSS was 3,540 tons, and the average output 

load was 2,080 tons (table 7, fig. 13B). Monthly VSS 

output loads were significantly lower (p-value = 

0.0001) than input loads (table 5). Annual removal 

efficiency ranged from 28.1 to 55.4 percent and 

averaged 41.0 percent for the study period (table 7, 

fig. 13C).

Input loads of TSS and VSS were strongly 

correlated with discharge (Spearman correlation 

coefficients exceeded 0.93; table 6), and large loads 

coincided with periods of storm runoff. Although the 

removal efficiencies for TSS and VSS were not 

significantly correlated with discharge or season, nor 

with the duration or depth of wetland inundation 

(table 6), the removal-efficiency plots for TSS and 

VSS (figs. 12C and 13C) indicated a strong relation 

with discharge (fig. 3B). Except for the prolonged dry 

period of 1991, TSS-removal efficiency fluctuated 

between about 40 and 60 percent, and the greatest 

removal efficiencies corresponded to high-discharge 

periods. The primary factors in the removal of TSS 

were the low channel gradient and the dense 

vegetation of the wetland, both of which facilitated the 

wetland’s sedimentation and filtration functions.

A TSS-removal efficiency of 49 percent 

reported for the Ellison Park wetland for the summer 

of 1972 by Harbison (1974) closely agrees with that 

computed from the 1991-96 data (table 7). In contrast, 

an average annual TSS-removal efficiency of only 12 

percent, was measured between Blossom Road and the 

Narrows for 1980-81 by Kappel and others (1986). 

This low value probably reflects the removal efficiency 

for the southern wetland area alone, however.

Chloride and Sulfate

The primary source of chloride in the 

Irondequoit Creek basin is the road salts that are 

applied to highways during the winter (Diment and 

others, 1974). Chloride is a highly soluble, 

conservative substance in that it does not precipitate 

nor enter actively into biological and chemical 

processes (Kadlec, 1987); thus, its mass remains 

relatively constant among surface-water inflow and 

outflow, and wetland storages (Kadlec and Knight, 

1996). Median concentrations of chloride at the inflow 

and outflow sites were 110 and 120 mg/L, 

respectively, and the interquartile ranges also were 

similar (table 7). The average estimated annual input 

load of chloride during the study was 16,800 tons, and 

the average output load was 17,500 tons (table 7). The 

differences among monthly loads were small but 

statistically significant (p-value = 0.0001; table 5). The 

annual removal efficiency ranged from -10.6 to 3.4 

percent and averaged -3.9 percent for the study 

(table 7). Road salt from the land surrounding the 

wetland downstream from the inflow site probably is 

the reason why the output loads were slightly greater 

than the input loads.

Chloride concentrations and loads (fig. 14) were 

elevated during the winter and low at other times. Peak 

chloride input and output loads occurred during 

periods of high discharge (figs. 3 and 14B; Spearman 

correlation coefficients of 0.91 and 0.92, respectively, 

table 6) and reflect the washoff of chloride during the 

high flows that occurred during the winter and spring 

snowmelt; chloride loads during summer stormflows 

were lower. Removal efficiency (fig. 14C) was positive 

during the high-water periods of 1991 and 1993 

(fig. 4), when the high water-surface elevations of 

Irondequoit Bay and Lake Ontario facilitated the 

dispersal and detention of flows, and was near-zero or 

negative during the prolonged low-water periods, 

when flows entering the wetland in the main channel 

of Irondequoit Creek had little opportunity for 

dispersal. Despite these observations, chlorideremoval efficiency was not statistically correlated with 

discharge, nor with depth or duration of inundation in 

the wetland (figs. 4 and 14). 

Sulfate is an airborne byproduct of fossil-fuel 

combustion and industrial processes, such as smelting 

of sulfide ores (Hem, 1989) and, thus, has a 

widespread distribution and settles to the earth as 

dryfall or is removed from the air by rain or snow. 

Sulfate is a soluble salt, and its concentrations and 
32 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

1991 1992 1993 1994 1995 1996

0

1,600

200

400

600

800

1,000

1,200

1,400

CONCENTRATION, IN MILLIGRAMS PER LITER

Blossom Road (inflow)

Empire Boulevard (outflow)

1991 1992 1993 1994 1995 1996

0

12,000

2,000

4,000

6,000

8,000

10,000

MONTHLY LOAD, IN TONS

Blossom Road (input load)

Empire Boulevard (output load)

TOTAL SUSPENDED SOLIDS

1991 1992 1993 1994 1995 1996

0

80

20

40

60

REMOVAL EFFICIENCY, IN PERCENT OF INPUT LOAD

B. MONTHLY LOAD

C. REMOVAL EFFICIENCY

A. CONCENTRATION

Figure 12. Concentration, monthly load, and wetland’s removal efficiency for total suspended solids, Ellison Park wetland, 

Monroe County, N.Y., 1990-96
33

1991 1992 1993 1994 1995 1996

0

200

50

100

150

CONCENTRATION, IN MILLIGRAMS PER LITER

Blossom Road (inflow)

Empire Boulevard (outflow)

1991 1992 1993 1994 1995 1996

0

1,200

200

400

600

800

1,000

MONTHLY LOAD, IN TONS

Blossom Road (input load)

Empire Boulevard (output load)

VOLATILE SUSPENDED SOLIDS

1991 1992 1993 1994 1995 1996

-20

80

0

20

40

60

REMOVAL EFFICIENCY, IN PERCENT OF INPUT LOAD

B. MONTHLY LOAD

C. REMOVAL EFFICIENCY

A. CONCENTRATION

Figure 13. Concentration, monthly load, and wetland’s removal efficiency for volatile suspended solids, Ellison Park 

wetland, Monroe County, N.Y., 1990-96
34 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

loads, like those of chloride, were not greatly affected 

by the wetland. Median sulfate concentrations were 

140 mg/L at the inflow and outflow sites, and the 

interquartile ranges differed little between the two 

sites (table 7). The plot of sulfate concentrations 

(fig. 15A) indicates seasonally high concentrations 

from midsummer through autumn of most years and 

low concentrations from late winter through spring. 

The average estimated annual input and output loads 

of sulfate were 16,000 and 15,700 tons, respectively 

(table 7), but the monthly output loads were 

significantly different from (slightly less than) the 

input loads (p-value = 0.0024; table 5). This decrease 

within the wetland could result from sulfate reduction 

under anaerobic conditions. The annual removal 

efficiency ranged from -2.4 to 7.4 percent and 

averaged 2.0 percent for the study period (table 7). 

The temporal pattern of input and output loads and 

removal efficiency (fig. 15) was similar to that for 

chloride (fig. 14).

Trace Metals

Water samples were collected from Irondequoit 

Creek during stormflows, and less frequently during 

low-flow periods, and were analyzed for four trace 

metals—zinc, lead, copper, and cadmium 

(appendix 1). The range of inflow and outflow 

concentrations of zinc, lead, and copper are shown in 

boxplots in figure 16; cadmium concentrations were 

usually below the analytical detection limit and were 

excluded. Concentrations at the inflow were generally 

greater than at the outflow. The median concentrations 

of these metals in Irondequoit Creek were compared 

with (1) average concentrations found in rivers 

worldwide (Kadlec and Knight, 1996) and in the 

United States (Hem, 1989; Durum and others, 1971), 

and (2) a summary statistic derived from the 

nationwide data collected during the 1980-81 NURP 

studies (U.S. Environmental Protection Agency, 

1983). Of the 13 metals for which urban-runoff 

samples from NURP study sites were analyzed, 

copper, lead and zinc were detected most 

frequently—in at least 91 percent of the samples, and 

in some samples at concentrations that exceeded U.S. 

Environmental Protection Agency water-quality 

standards (U.S. Environmental Protection Agency, 

1983). The mean concentration of a given constituent 

during a specific stormflow (or event mean 

concentration, EMC) at a NURP site was computed as 

the total constituent mass divided by the total runoff 

volume (U.S. Environmental Protection Agency, 1983) 

and was used to normalize the data for differences in 

precipitation and runoff among the study sites. The 

median EMC for each constituent from each NURP 

site was computed, and the median value of the ranked 

medians from all NURP sites was used as a 

nationwide summary statistic for each constituent. 

Zinc

Zinc, an essential micronutrient for plants and 

animals, is naturally occurring but becomes widely 

distributed in the environment through its many uses. 

It is used in dry-cell batteries, building materials, and 

alloys such as brass and bronze (Windholz, 1983); 

galvanized steel, paint pigment, and rubber (Hem, 

1989). Median zinc concentrations in streams 

worldwide are reported to be between 5 and 45 μg/L 

(Hem, 1989), and the average concentration is 

estimated to be 10 μg/L (Kadlec and Knight, 1996). A 

median value of 20 μg/L has been reported for U.S. 

streams in 1970 by Durum and others (1971). The 

NURP median EMC concentration of zinc was 

160 μg/L (U.S. Environmental Protection Agency, 

1983), but this value represents zinc concentrations in 

urban stormwater, which do not reflect average 

conditions. Median concentrations of zinc in 

Irondequoit Creek at the wetland inflow and outflow 

during this study were 40 μg/L (fig. 16), but the 

outflow concentrations were significantly lower than 

the inflow concentrations (p-value = 0.0078; table 8). 

The maximum zinc concentrations at the inflow and 

outflow were 370 μg/L and 150 μg/L, respectively. 

The elevated zinc concentrations in the Irondequoit 

Creek basin are most likely a result of urbanization but 

also could be due partly to the dissociation of zinc 

sulfide from dolomite, which underlies part of the 

basin and is also within the overlying glacial deposits 

and local soils (Kappel and others, 1986). Removal of 

zinc by wetlands results from adsorption, 

sedimentation, ion exchange, formation of insoluble 

compounds such as zinc sulfide, which then 

precipitate, and through bioaccumulation, primarily in 

plant roots (Hem, 1989; Kadlec and Knight, 1996).

Lead

Lead has low solubility, adsorbs readily to 

organic and inorganic-sediment surfaces (Hem, 1989), 

and forms insoluble salts with sulfides, carbonates, 

sulfates, and chlorophosphates (Kadlec and Knight, 

1996). Manmade sources of lead include pipes, 
35

1991 1992 1993 1994 1995 1996

0

600

100

200

300

400

500

CONCENTRATION, IN MILLIGRAMS PER LITER

Blossom Road (inflow)

Empire Boulevard (outflow)

1991 1992 1993 1994 1995 1996

0

4,000

1,000

2,000

3,000

MONTHLY LOAD, IN TONS

Blossom Road (input load)

Empire Boulevard (output load)

CHLORIDE, DISSOLVED

1991 1992 1993 1994 1995 1996

-30

30

-20

-10

0

10

20

REMOVAL EFFICIENCY, IN PERCENT OF INPUT LOAD

A. CONCENTRATION

B. MONTHLY LOAD

C. REMOVAL EFFICIENCY

Figure 14. Concentration, monthly load, and wetland’s removal efficiency for chloride, Ellison Park wetland, Monroe County, 

N.Y., 1990-96
36 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

1991 1992 1993 1994 1995 1996

0

350

100

200

300

CONCENTRATION, IN MILLIGRAMS PER LITER

Blossom Road (inflow)

Empire Boulevard (outflow)

1991 1992 1993 1994 1995 1996

500

3,000

1,000

1,500

2,000

2,500

MONTHLY LOAD, IN TONS

Blossom Road (input load)

Empire Boulevard (output load)

SULFATE, DISSOLVED

1991 1992 1993 1994 1995 1996

-20

20

-10

0

10

REMOVAL EFFICIENCY, IN PERCENT OF INPUT LOAD

C. REMOVAL EFFICIENCY

B. MONTHLY LOAD

A. CONCENTRATION

Figure 15. Concentration, monthly load, and wetland’s removal efficiency for sulfate, Ellison Park wetland, Monroe County, 

N.Y., 1990-96 
37

(76)

(70)

bcu ecu 0

160

20

40

60

80

100

120

140

CONCENTRATION, IN MICROGRAMS PER LITER

EXPLANATION

Detection limit

25th percentile

Median

75th percentile

the interquartile range outside the quartile

Data value less than or equal to 1.5 times

interquartile range outside the quartile

and more than 1.5 times the

Outlier data value less than or equal to 3

interquartile range outside the quartile

Outlier data value more than 3 times the

(76) Number of observations

(80)

(76)

0

100

20

40

60

80

(71)

(61)

0

400

50

100

150

200

250

300

350

CONCENTRATION, IN MICROGRAMS PER LITER

TOTAL 

RECOVERABLE 

COPPER

TOTAL 

RECOVERABLE 

LEAD

TOTAL 

RECOVERABLE 

ZINC

Blossom

Road

Blossom

Road

Empire

Boulevard

Empire

Boulevard

plastics, ceramics, paints, batteries, smelting of ores, 

and combustion of coal and leaded gasoline (Hem, 

1989; Windholz, 1983). Lead concentration in the 

world’s rivers averages about 0.2 μg/L (Kadlec and 

Knight, 1996), and that in U.S. streams ranges 

between 1 and 10 μg/L (Hem, 1989; Durum and 

others, 1971). The NURP median EMC concentration 

of lead in urban stormwater was 144 μg/L (U.S. 

Environmental Protection Agency, 1983). Median 

concentrations of lead in Irondequoit Creek during this 

study were 7 μg/L at the inflow and 5 μg/L at the 

outflow (fig. 16), a significant decrease (p-value = 

Figure 16. Concentrations of selected trace metals in stormwater samples from Irondequoit Creek above Blossom Road 

and at Empire Boulevard, Monroe County, N.Y., 1990-96
38 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

0.0096; table 8). The maximum lead concentrations at 

the inflow and outflow were 84 μg/L and 39 μg/L, 

respectively. Lead removal in wetlands results from 

the formation of insoluble compounds and subsequent 

sedimentation; lead also can become biomagnified in 

aquatic biota (Kadlec and Knight, 1996).

Copper

Copper is an essential micronutrient for plants 

and animals and enters the environment from its use in 

water pipes and plumbing fixtures; it also is used in 

algicides and pesticides (Hem, 1989), in alloys such as 

bronze and brass, and in electrical conductors, 

ammunition, and wood preservatives (Windholz, 

1983). Another source, particularly in urban settings, 

is the abrasion of vehicle brake pads (WoodwardClyde Consultants, 1994; 1997). Of the 13 metals 

detected in NURP urban-runoff samples, copper was 

the most frequently detected (U.S. Environmental 

Protection Agency, 1983). The average copper 

concentration in the world’s rivers is about 2 μg/L 

(Kadlec and Knight, 1996), and that in U.S. streams is 

about 10 μg/L (Hem, 1989; Durum and others, 1971). 

The NURP median EMC concentration was 34 μg/L 

(U.S. Environmental Protection Agency, 1983). 

Median concentrations at the wetland inflow and 

outflow during this study were 50 μg/L and 40 μg/L, 

respectively (fig. 16), but this apparent decrease was 

not statistically significant (α = 0.10; table 8). The 

maximum copper concentrations at the inflow and 

outflow were 120 μg/L and 100 μg/L, respectively. 

The data indicate a decrease in concentrations from 

1990 through 1996 (appendix 1). Wetlands can 

decrease copper loads through adsorption on mineral 

and organic surfaces, through the formation of 

complexes with hydroxides, sulfides, and carbonates, 

and through bioaccumulation in plant tissues (Kadlec 

and Knight, 1996). 

Cadmium

Cadmium is a naturally occurring element that 

enters the environment through industrial uses, which 

include electroplating and photography; it also is used 

in paint pigment, printing ink, and plastics, and as a 

stabilizer in PVC products, in electrical batteries, and 

in fluorescent and video tubes (Hem, 1989; Windholz, 

1983). The average concentration of cadmium in 

surface waters worldwide is about 0.07 μg/L (Kadlec 

and Knight, 1996) and about 1 μg/L in U.S. streams 

(Hem, 1989; Durum and others, 1971). Cadmium 

concentrations in 76 and 83 percent of the samples 

collected at the wetland inflow and outflow, 

respectively, were below the analytical detection limit 

of 1 μg/L. Nonetheless, the outflow concentrations, 

when detected, were significantly lower than the 

inflow concentrations (p-value = 0.0265; table 8). 

Maximum cadmium concentrations at the inflow and 

outflow during this study were 3 μg/L and 4 μg/L, 

respectively. The removal efficiency for cadmium in 

most wetlands is greater than 75 percent. Removal is 

achieved through adsorption on organic particles and 

the formation, and subsequent sedimentation, of 

sulfides (Kadlec and Knight, 1996). 

Table 8. Selected statistics on trace-metal concentrations in Irondequoit Creek above Blossom Road (wetland inlet) and 

at Empire Boulevard (wetland outlet), Monroe County, N.Y., 1990-96

[mg/L, milligrams per liter; <, less than. Dash indicates no conclusion can be stated. Locations are shown in fig. 2.] 

Metal

Number of observations

Censoring

limit(s),1

mg/L

1Censoring limit varies with equipment used for analysis.

Median 

concentration, mg/L

p-value

Wilcoxon

Rank

Sum test2

2Test of significant difference between median inflow and outflow concentrations.

Significant 

difference

Point of 

greater

concentration

Inflow Outflow

Total Censored Total Censored Inflow Outflow

Zinc 783 220 659 192 40 40 40 0.0078 yes inflow

Lead 79 21 76 25 2, 5 7 5 .0096 yes inflow

Copper 77 7 73 6 10, 20, 50 50 40 .89 no --

Cadmium 82 62 78 65 1, 5 < 1.0 < 1.0 .0265 yes inflow
39

Water Temperature

Surface-water temperature increased by passage 

through the wetland, especially during the summer 

(fig. 17A), through the slow movement of water, the 

shallow conditions, and the absence of shade. Winter 

water temperatures at the outflow site were similar to 

those at the inflow site; daily mean temperatures at the 

outflow usually differed from those at the inflow by 

less than 0.5 °C (fig. 17B), except in late spring and 

summer, when daily mean outflow temperatures were 

generally 1 to 2 °C higher than the inflow temperatures 

(fig. 17B). This difference narrowed during periods of 

storm runoff, as shown by the temperature record and 

storm hydrograph (fig. 17C) for June 18-28, 1996. The 

diurnal temperature pattern at the inflow site was not 

greatly affected by the runoff, except on June 19 and 

20, when the runoff shifted the time of the peak 

temperatures. At the outflow site, the runoff lowered 

the water temperature to as low as the inflow 

temperature or lower. This cooling was enhanced by 

cloudy conditions on June 18-20, when less than 20 

percent of possible sunshine was recorded (Northeast 

Regional Climate Center, 1996). Soon after the 

passage of the stormwater, temperatures at both sites 

increased, and the difference in the temperature 

records increased to prestorm values. 

Characteristics of Wetland Sediments

The composition of channel-bottom material 

varies within the Ellison Park wetland according to the 

flow velocity. The predominant bed material in the 

main channel (Irondequoit Creek), in which high flow 

velocities occur, is sand, but the predominant bed 

materials in the open, backwater areas where 

velocities are slow are silt and clay. The four bottomsediment samples collected for chemical analyses 

(fig. 2) were taken from backwater areas; more than 82 

percent of the particles were silt sized and smaller 

(less than 4 mm in diameter). The high percentage of 

fine-grained mineral particles reflects the wetland’s 

high removal efficiency for suspended solids that 

accumulate in these depositional environments. The 

sediment samples were 3.4 to 5.0 percent total organic 

carbon by weight and contained 0.13 percent 

phosphorus by weight. The relatively low 

concentrations of organic carbon in these samples 

reflects the low rate of biomass accumulation from 

small submergent aquatic macrophytes (such as 

Myriophyllum sp. and Ceratophyllum demersum). The 

organic content in the cattail-vegetated (Typha glauca) 

areas of the wetland is expected to be substantially 

greater than that indicated by these results. 

Results of the sediment analyses are presented 

in appendix 4. The high percentage of silt and clay in 

the sediment, and the presence of organic matter, are 

conducive to adsorption of metals (Hem, 1989) and 

organic compounds (Smith and others, 1988). Metals 

found in elevated concentrations (greater than 

200 ppm; see table 9) included barium, manganese, 

strontium, and zinc; these concentrations were within 

the range expected for water draining an urbanized 

watershed, however (E.C. Callender, U.S. Geological 

Survey, written commun., 1996). The elevated 

concentrations of these and other trace elements, 

including chromium, copper, lead, and vanadium, 

could be indicative of the effectiveness of the 

wetland’s removal processes, as substantiated by the 

decrease in surface-water concentrations of lead and 

zinc between the inflow- and outflow-sampling sites, 

or the attainment of the wetland’s maximum retention 

capacity. Another major mechanism for removal of 

metals is the uptake and possible bioaccumulation by 

plants, especially in roots and rhizomes, as discussed 

in the following section.

Some polycyclic aromatic hydrocarbons 

(PAH’s), including chrysene, fluoranthene, 

phenanthrene, and pyrene, also were found in high 

concentrations in the wetland sediments, as were five 

persistent organochlorine pesticides (chlordane, 

dieldrin, DDT and its metabolic-degradation products, 

DDD and DDE) and polychlorinated biphenyls 

(PCB’s) (table 9). The presence, and the magnitude of 

concentrations, of these compounds are fairly typical 

of a depositional environment in a highly urbanized 

watershed, and many of the pesticide and PCB 

concentrations are comparable to or lower than those 

measured in 14 studies in the United States during the 

1970’s and 1980’s, as reported by Smith and others 

(1988, p. 33). Concentrations of cadmium, copper, 

mercury, silver, and all detected PAH’s were 

noticeably higher in the sample from the northern 

(downstream) part of the wetland than in the three 

samples from the southern part, possibly as a result of 

current or past chemical inputs from the adjacent 

drainage area, but no definite conclusions can be 

drawn from these sparse data.

Wetland sediments can act as a sink for 

chemicals that (1) precipitate out of solution as 
40 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

D J F M A M J J A S O N D J F M A M J J A S

1994 1995 1996

0

30

10

20

TEMPERATURE, IN DEGREES CELSIUS

Blossom Road

Empire Boulevard

O N D J F M A M J J A S

1995 1996

0

30

10

20

TEMPERATURE, IN DEGREES, CELSIUS

Blossom Road (inflow)

Empire Boulevard (outflow)

B. DAILY MEAN WATER TEMPERATURE

1996 WATER YEAR

18 19 20 21 22 23 24 25 26 27 28

June 1996

16

24

18

20

22

TEMPERATURE, IN DEGREES CELSIUS

Blossom Road (inflow)

Empire Boulevard (outflow)

C. WATER TEMPERATURE DURING SUMMER STORM RUNOFF

18 19 20 21 22 23 24 25 26 27 28

June 1996

0

800

200

400

600

DISCHARGE, IN CUBIC FEET PER SECOND

Discharge at Irondequoit Creek

above Blossom Road

D. STORM HYDROGRAPH (INFLOW TO THE WETLAND)

A. MONTHLY MEAN WATER TEMPERATURE, 1994-96

Figure 17. Water temperatures at Irondequoit Creek above 

Blossom Road and at Empire Boulevard, Monroe County, N.Y.: A. Monthly mean water temperature, 1994-96. B. Daily mean 

water temperature, 1996 water year. C. Water temperature and D. hydrograph during storm runoff period, June 18-28, 1996
41

insoluble salts, (2) are in particulate form, or (3) 

adsorb to mineral and organic particles (Kadlec and 

Knight, 1996). The storage potential of wetland soils 

for sorptive chemicals becomes limited, however, 

when the soil’s capacity is reached (Mitsch and 

Gosselink, 1986; Gehrels and Mulamoottil, 1989; 

Kadlec and Knight, 1996). Thus, the only mechanism 

for increasing the capacity for long-term storage of 

chemicals is the accretion and subsequent burial of 

organic matter and the insoluble, particulate, and 

adsorbed chemicals

Characteristics of Wetland Vegetation 

(Typha glauca)

Vegetation plays an important role in the 

wetland’s effectiveness in improving water quality. 

Plants provide filtration, nutrient assimilation and 

translocation, heavy-metal uptake, and surfaces for 

microbial growth and their subsequent utilization of 

nutrients (Kadlec and Knight, 1996). The Ellison Park 

wetland is an ideal environment for cattails, Typha 

glauca, which cover more than 60 percent of it. The 

cattails are extremely tall (more than 10 ft at the peak 

of the growing season) and have a high density, a large 

biomass, and a considerable capacity for taking up and 

utilizing nutrients during the growing season. 

Density and Biomass

Characteristics of Typha glauca in the southern 

and northern parts of the wetland, including density, 

height, percentage of land surface covered, and 

biomass, for the two flora studies conducted during 

1991 and 1996 are presented in table 10. About 63 

percent, or 265 acres, of the wetland’s land surface 

Table 9. Concentrations of selected chemicals in sediment of Ellison Park wetland, Monroe County, N.Y., October 19941

[Concentrations are average values from four samples. Percentages are by dry weight.] 

1 Values for other trace elements, organochlorine compounds, and polycyclic aromatic hydrocarbons that were not found 

in concentrations above the analytical detection limit are tabulated in Coon (1997).

Elements

Percent or 

concentration Elements Concentration Organic compounds Concentration

Percent by weight Parts per million (cont.) Parts per billion

Aluminum 4.9 Gallium 12 Chlordane 22

Calcium 6.0 Lanthanum 24 DDD 4.8

Carbon, organic 4.0 Lead 65 DDE 7.5

Carbon, inorganic 1.7 Lithium 27 DDT .8

Iron 2.6 Manganese 710 Dieldrin 2.2

Magnesium 1.3 Mercury .19 PCB 40

Phosphorus .13 Neodymium 24 Benzo a anthracene 850

Potassium 1.6 Nickel 20 Benzo b fluoranthene 1,000

Sodium 1.2 Niobium 11 Benzo k fluoranthene 1,040

Sulfur .43 Scandium 8 Benzo a pyrene 800

Titanium .26 Selenium .7 Bis(2-ethyhexyl) phthalate 600

Parts per million Silver 1.2 Chrysene 1,100

Antimony 0.4 Strontium 400 Fluoranthene 2,080

Arsenic 4.6 Thorium 6.2 Phenanthrene 920

Barium 460 Uranium 1.6 Pyrene 1720

Beryllium 1 Vanadium 48

Cadmium 1.8 Yttrium 19

Cerium 43 Ytterbium 2

Chromium 49 Zinc 230

Cobalt 11

Copper 54
42 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

was covered by cattails. Cattail density ranged from 31 

to 38 shoots per 1-m2

 (3.3-ft2) plot and averaged 34 

shoots/m2

. These shoots averaged about 280 cm 

(9.2 ft) in height, and those in the northern part of the 

wetland averaged more than 300 cm (9.8 ft) in 1991 

and attained maximum heights of 350 cm (11.5 ft). 

Cattail density and height varied with soil wetness; dry 

areas along streambanks and deep-water areas, where 

water depth exceeded about 40 cm (15 in.), yielded 

lower productivity than areas where the water level 

was between a few centimeters and about 30 cm 

(12 in.) above the top of the cattail mat.

The average weight of an individual shoot was 

76 g; the maximum average was 90 g for plants in the 

northern part of the wetland during 1996. These long, 

dense shoots yielded a large biomass that averaged 

2,608 g/m2

 above ground (46 percent of the total 

biomass) and 3,025 g/m2

 below ground. Maximum 

values were found in the northern wetland area during 

1996. Above- and below-ground biomass exceeded 

most values reported by other researchers; reported 

measurements of peak above-ground biomass in Typha 

glauca range from 1,281 g/m2

 in an Iowa marsh (Van 

der Valk and Davis, 1978) to 1,361 g/m2

 in a central 

New York site (Bernard and Fitz, 1979) to 2,320 g/m2

in a Minnesota marsh (Andrews and Pratt, 1978). Peak 

shoot biomass of other Typha species range from 

1,118 to 2,338 g/m2

 (Whigham and others, 1978; 

Mason and Bryant, 1975; McNaughton, 1966; Van der 

Valk and Davis, 1978; Boyd and Hess, 1970; Boyd, 

1971; Bray, Lawrence, and Pearson, 1959). Reported 

measurements of peak below-ground biomass in 

Typha glauca range from 1,450 g/m2

 in an Iowa marsh 

(Van der Valk and Davis, 1978) to 2,960 g/m2

 (Bray, 

1960) and 3,100 g/m2

 (Andrews and Pratt, 1978) in 

two Minnesota sites. Peak below-ground biomass of 

other Typha species range from 2,646 to 5,053 g/m2

(Whigham and others, 1978; McNaughton, 1966). 

Reported values for total biomass, which is 

infrequently measured, range from 3,405 g/m2

 in 

Oregon and 3,982 g/m2

 in Texas (McNaughton, 1966) 

to 4,230 and 4,720 g/m2

 in Minnesota (Andrews and 

Pratt, 1978; Bray, 1960). Total biomass measured in 

the Ellison Park wetland ranged from 4,801 g/m2

 in 

the southern area in 1991 to 7,085 g/m2

 in the northern 

area in 1996 and averaged 5,633 g/m2

 over the two 

study periods (table 10).

The values for all these characteristics, except 

cattail height in the northern area and below-ground 

biomass in the southern area, were lower in 1991 than 

in 1996, perhaps as a result of differences in sampling 

date, or chance variation in sampling resulting from 

differences in water depth, temperature, or other 

environmental factors. Seasonal variations in cattail 

biomass have been documented by many of the studies 

referenced above. Annual variation in wetland-plant 

biomass also has been reported: for example, a 37-

percent difference in above-ground biomass of 

Phragmites australis, another emergent wetland plant, 

was found in Norfolk, England over a 3-yr period 

(Boar, 1996). Therefore, the mean values for both 

sampling periods (1991 and 1996) are considered 

reliable representations of the average values for 

cattails over the entire wetland (table 10).

Nutrients and Trace Metals 

Results of the chemical analyses of cattail tissue 

are presented in table 11; the values represent aboveand below-ground tissues collected from both parts of 

Table 10. Characteristics of Typha glauca in Ellison Park wetland, Monroe County, N.Y., 1991 and 1996

[g/m2, grams per square meter. Values are averages of samples collected along the specified transect. Data from Bernard and 

Seischab (1991, 1997).]

Characteristic

Transect location within wetland

Overall 

mean

1991 1996

Southern part Northern part Southern part Northern part

Number of 1-square-meter plots 31 26 31 20 27

Number of shoots per square meter 32 31 35 38 34

Height, centimeters 212 318 290 297 279

Percentage of land surface covered 68 79 88 97 83

Weight per shoot, grams 65 76 72 90 76

Above-ground biomass, g/m2

 2094 2368 2505 3466 2608

Below-ground biomass, g/m2

 2707 3291 2484 3619 3025

Total biomass, g/m2

 4801 5659 4989 7085 5633
43

the wetland during the two study periods (1991 and 

1996). No striking differences are evident between the 

above-ground tissue data for 1991 and those for 1996, 

except possibly for aluminum and manganese 

concentrations, both of which were more than twice as 

great in 1991 as in 1996. The 1991 below-ground 

tissue data for most constituents also were similar to 

the 1996 data, except for boron concentrations, which 

were almost three times higher in 1991 than in 1996. 

Concentrations of sodium and lead were not measured 

in 1996.

Above-ground cattail tissues assimilated an 

average of 2.4 and 0.3 percent of their dry weight in 

nitrogen and phosphorus, respectively. Of the major 

macronutrients, nitrogen and potassium were found in 

higher concentrations in above-ground tissues (2.4 and 

1.5 percent by dry weight, respectively) than in belowground tissues; calcium and magnesium were found in 

higher concentrations in below-ground tissues. Aboveground concentrations of phosphorus, as well as 

molybdenum and manganese, were similar to those 

below ground; concentrations of all other chemicals 

were considerably higher in below-ground tissues. 

Concentrations of manganese (417 ppm) and sodium 

(3,600 ppm) in above-ground tissues were 

exceptionally high, as were those of aluminum (1,540 

ppm), iron (15,400 ppm), manganese (433 ppm), and 

sodium (10,000 ppm) in below-ground tissues. These 

concentrations exceeded those typically found in a 

wide range of aquatic plants in natural wetlands 

(Hutchinson, 1975; Vitosh and others, 1973). The 

chemical composition of the Ellison Park cattails was 

generally within the range observed at two other 

cattail-study sites—a natural marsh in South Carolina 

(Boyd, 1970) and a constructed wetland in New York 

that receives landfill leachate (Bouldin and others, 

1993). An exception was sodium, which was found in 

higher concentrations in the Ellison Park cattails than 

in those at the other sites, presumably as a result of 

winter road-salt application in the basin. Also, as in 

other studies, the highest concentration of 

micronutrients was found in below-ground tissues.

Chemical Standing Stocks

The standing stock of an element in an 

ecosystem is defined as the total mass of that element, 

Table 11. Average dry-weight percentage or concentration of selected elements in above- and belowground biomass of Typha glauca in Ellison Park wetland, Monroe County, N.Y., 1991 and 1996

[%, percent by weight; ppm, parts per million. Dash indicates no data.]

Element

Above-ground biomass Below-ground biomass

1991 1996 Mean 1991 1996 Mean

Nitrogen, % 2.6 2.3 2.4 0.8 0.8 0.8

Phosphorus, % .3 .3 .3 .2 .2 .2

Potassium, % 1.4 1.7 1.5 .4 .6 .5

Calcium, % 1.0 .8 .9 1.3 1.4 1.4

Magnesium, % .2 .18 .19 .5 .5 .5

Copper, ppm 5.3 3.9 4.6 15.6 13.9 14.7

Nickel, ppm 1.6 1.1 1.4 9.6 11.7 10.6

Chromium, ppm 1.4 .12 .8 6.0 5.2 5.6

Cobalt, ppm .1 .1 .1 .6 .6 .6

Molybdenum, ppm .4 .5 .5 .6 .5 .5

Zinc, ppm 17.5 13.5 15.5 59.8 48.5 54.1

Aluminum, ppm 17.3 6.0 11.6 1,880 1,200 1,540

Iron, ppm 67.4 56.6 62.0 18,000 12,800 15,400

Boron, ppm 12.1 7.0 9.6 132 46.5 89.2

Manganese, ppm 598 236 417 458 408 433

Sodium, ppm 3,600 -- 3,600 10,000 -- 10,000

Lead, ppm .6 -- .6 18.9 -- 18.9
44 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

computed as the product of the element’s 

concentration and the total biomass of the ecosystem. 

The total standing stocks of elements in above- and 

below-ground cattail tissues for 1991 and 1996, and 

the percentage of the total in the above-ground tissues, 

are presented in table 12. The above-ground tissue 

samples contained more than half of the total standing 

stocks of only three elements—nitrogen (73 percent), 

phosphorus (54 percent), and potassium (72 percent). 

Nitrogen had the largest above-ground standing stocks 

of any constituent measured, averaging almost 

60 g/m2

; phosphorus, had just over 6 g/m2 in aboveground tissues. Other elements with large aboveground standing stocks included potassium (37 g/m2

), 

calcium (23 g/m2

), and sodium (7 g/m2). The other 

elements, especially the metals, tended to be 

concentrated in below-ground tissues; 98 percent of 

standing stocks of lead and more than 99 percent of 

standing stocks of iron and aluminum were found in 

below-ground tissues. Other elements with large 

below-ground standing stocks were iron (41 g/m2

), 

calcium (37 g/m2

), sodium (24 g/m2), magnesium 

(14 g/m2

), and aluminum (4 g/m2). 

Water-Quality-Improvement Function of 

Ellison Park Wetland

A wetland’s ability to improve water quality by 

the retention or removal of sediment and nutrients 

carried in stormwater, and the mechanisms by which 

this is achieved, are of special interest to waterresources managers, especially if the wetland is in an 

urban setting. The Ellison Park wetland is smaller than 

would be desired for a constructed wetland designed 

to effectively treat the volume and quality of 

stormwater that passes through it (the wetland covers 

0.5 percent of Irondequoit Creek’s drainage area). The 

water-quality, sediment, and biomass data obtained in 

this study indicate that the wetland provides effective 

stormwater treatment despite its small size and poor 

dispersal of all but the largest stormflows. The loads of 

particulate constituents (total phosphorus and 

suspended solids) and of constituents that form 

precipitates or that adsorb to, or chemically bind with, 

fine-grained sediment particles or organic matter 

(metals and organic chemicals) were significantly 

decreased by sedimentation and vegetative filtration. 

The loads of other constituents, such as organic 

Table 12. Average standing stocks of selected elements in above- and below-ground biomass of Typha glauca in

Ellison Park wetland, Monroe County, N.Y., 1991 and 1996

[g/m2, grams per square meter; mg/m2, milligrams per square meter. Dash indicates no data.] 

Element

Above-ground standing stock Below-ground standing stock Total mean

standing 

stock

Percent 

standing stock 

1991 1996 Mean 1991 1996 Mean above ground

Nitrogen, g/m2 50.1 68.1 59.1 19.1 23.8 21.4 80.5 73

Phosphorus, g/m2 4.8 8.3 6.5 5.2 6.0 5.6 12.1 54

Potassium, g/m2 27.0 47.8 37.4 9.6 19.6 14.6 52.0 72

Calcium, g/m2 19.2 26.5 22.8 30.4 43.6 37.0 59.8 38

Magnesium, g/m2 3.8 5.4 4.6 10.8 16.4 13.6 18.2 25

Iron, g/m2 .13 .17 .15 43.4 39.4 41.4 41.6 .4

Manganese, g/m2 1.2 .7 .9 1.0 1.2 1.1 2.0 45

Sodium, g/m2 6.9 -- 6.9 24.1 -- 24.1 31.0 22

Copper, mg/m2 10.2 11.8 11.0 37.6 41.8 39.7 50.7 22

Nickel, mg/m2 3.0 3.0 3.0 23.1 35.4 29.2 32.2 9

Chromium, mg/m2 2.6 .3 1.4 14.4 15.0 14.7 16.1 9

Cobalt, mg/m2 .09 .20 .14 1.4 1.8 1.2 1.3 11

Molybdenum, mg/m2 .8 1.5 1.1 1.4 1.5 1.4 2.5 44

Zinc, mg/m2 33.6 40.2 36.9 144 149 146 183 20

Aluminum, mg/m2 33.3 17.5 25.4 4,524 3,662 4,093 4,118 .6

Boron, mg/m2 23.2 20.4 21.8 320 140 230 252 9

Lead, mg/m2 1.1 -- 1.1 45.6 -- 45.6 46.7 2
45

nitrogen, nitrate plus nitrite, and sulfate, were 

moderately decreased, although the long-term (6-year) 

removal efficiencies were low, less than 8 percent.

The input-output relations and the chemicalremoval efficiencies found in this study were 

determined mainly by: (1) inflow loading rates, (2) 

storage or release mechanisms in the sediments, and 

(3) accretion and burial of organic detritus. The 

chemical loads and removal efficiencies for most 

constituents were directly related to stream discharge; 

that is, high flows produced large chemical loads and 

resulted in high removal efficiencies for constituents 

that were affected by the wetland, and low flows 

generally resulted in low removal efficiencies (relative 

to a given constituent). 

Many of the chemicals, such as the metals, for 

which the cattail-tissue samples were analyzed, were 

more abundant in below-ground tissue than in aboveground tissue, but even nitrogen, phosphorus, and 

potassium, whose above-ground standing stocks were 

large during the growing season, might have been 

translocated below ground prior to senescence and 

stored during the winter. Generally T. glauca retains 

less than half of the summer standing stocks of these 

nutrients at the time of senescence (Bernard and Fitz, 

1979); the remainder may be released into the water, 

and large releases of elements during fall and winter 

have been documented in some studies (Mason and 

Bryant, 1975; Gehrels and Mulamoottil, 1989). The 

chemical concentrations of some constituents showed 

seasonal patterns in this study, but most of the patterns 

were evident in the inflow data as well as the outflow 

data and, therefore, cannot be attributed to wetland 

processes alone. The chemical load data also do not 

indicate a seasonal release of nutrients during 

senescence, except possibly for nitrate plus nitrite, but 

do indicate that large amounts of chemicals are stored 

in the sediments and below-ground biomass. In 

addition to this long-term retention of nutrients and 

trace elements, the above-ground biomass and the 

microbial community provide a seasonal storage of 

chemicals. This seasonal retention is not reflected by 

the surface-water output loads of most constituents, 

however, and indicates that most of the seasonal 

nutrient needs of flora and microbes are not met by 

surface-water inputs, but through internal cycling of 

chemicals from the sediments and detritus, and that 

vegetative assimilation generally did not measurably 

decrease the nutrient loads in surface water passing 

through the wetland. A similar conclusion was reached 

by Johnston (1991), who reviewed the results of many 

wetland studies and noted that, with the exception of 

floating plants, vegetative uptake often is less 

important in sediment and nutrient retention in 

wetlands than physical and microbial processes. In the 

Ellison Park wetland, physical processes are the 

primary mechanisms for the decrease in surface-water 

chemical loads, but the effect of microbial processes, 

although considered substantial, were not studied 

directly and, except for the generation of ammonia 

nitrogen, had no identifiable effect on surface-water 

chemical loads.

The two removal processes that can be 

considered ultimate sinks for nutrients retained in a 

Typha sp. wetland are denitrification and the 

permanent burial of nutrients in sediment (Prentki and 

others, 1978). The effectiveness of burial is dependent 

on the availability of buried nutrients in root-zone 

soils, and the susceptibility of these nutrients to 

reuptake by wetland plants and subsequent release 

back into surface waters. If the depth of burial is 

sufficient to inhibit the translocation of nutrients in 

this manner, accretion and burial of sediment and dead 

but undecomposed plant tissues will be an effective 

nutrient trap and would provide a long-term removal 

mechanism for some chemicals. The magnitude of this 

removal mechanism in the Ellison Park wetland has 

not been documented, however. 

Progress Toward Water-Quality 

Improvement of Irondequoit Bay 

Improvement of the ecological and recreational 

status of Irondequoit Bay through control of nutrient 

loads entering the bay have been management 

objectives of Monroe County since the 1970’s. 

Progress toward these objectives has been monitored 

by (1) evaluation of the bay’s trophic status through 

periodic sampling of summer phytoplankton 

chlorophyll_a concentrations and calculation of 

biologically available phosphorus concentrations in 

the bay, and (2) estimation of constituent loads 

entering the bay in surface-runoff. 

Trophic Status

Two limnological measures of lake fertility are 

concentrations of phytoplankton chlorophyll, a 

measure of algal growth present, and phosphorus, a 

productivity-limiting nutrient. Chlorophyll_a
46 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

concentrations have been measured in Irondequoit Bay 

since 1971 (MCEHL, written comm., 1997). Biweekly 

water samples are collected at a measuring site at the 

deepest point in the bay between May 1 and October 

31 at about 3-ft intervals through about 20 ft of depth 

in the epilimnion. Concentrations of chlorophyll_a

within the water column are averaged for a given day, 

and the mean of these daily values is used as the 

summer mean chlorophyll concentration. The 

potential, or biologically available, phosphorus 

concentration in the bay is computed from the annual 

total-phosphorus load and surface-water discharge to 

the system, and the bay’s mean depth and surface area 

(Vollenweider, 1976). The chlorophyll_a and 

potential-phosphorus concentrations in the bay 

indicated the eutrophic conditions during the 1970’s, 

when effluent from sewage-treatment plants was 

discharged into Irondequoit Creek (fig. 18). These 

concentrations have decreased in response to the 

cessation of effluent discharges in 1977 and, possibly, 

to erosion- and stormwater-control measures 

implemented by Monroe County to decrease chemical 

loads from nonpoint sources in the basin. The trophic 

state of Irondequoit Bay has improved during the last 

20 years, but this improvement has not reached target 

levels nor returned the bay to mesotrophic conditions.

Temporal Trends in Chemical Loads

Data from this study indicate that the average 

annual loads of selected chemical constituents 

entering Irondequoit Bay, as measured at the Empire 

Boulevard monitoring site and adjusted for the 

intervening surface-drainage area, are: total nitrogen, 

289 tons, which includes 130 tons of ammonia-plusorganic nitrogen and 159 tons of nitrate-plus-nitrite 

nitrogen; total phosphorus, 21 tons; total suspended 

solids, 16,700 tons; dissolved chloride, 19,200 tons; 

and sulfate, 17,200 tons (table 13). Corresponding 

71

77

78

79 81 80

82

83

84

85

86

87

88

89 90

91 92

93

94

95

96

20 30 40 50 70 100 200 300 400 500 700 1,000

POTENTIAL PHOSPHORUS CONCENTRATION, IN MILLIGRAMS PER CUBIC METER

2

100

3

4

5

7

10

20

30

40

50

70

SUMMER MEAN CHLOROPHYLL_A CONCENTRATION, IN MILLIGRAMS PER CUBIC METER

TARGET RANGE OF

EUTROPHIC 

(Nutrient rich)

MESOTROPHIC 

(Nutrient balanced)

OLIGOTROPHIC 

(Nutrient poor)

WATER QUALITY 

MANAGEMENT PLAN

Figure 18. Trophic state of Irondequoit Bay, 1971-96, based on measured chlorophyll_a and computed potentialphosphorus concentrations (Source: Monroe County Environmental Health Laboratory.)
47

values calculated from data collected during 1980-81 

and 1984-88 (Kappel and others, 1986; Johnston and 

Sherwood, 1996) should indicate whether decreasing 

trends are present, but these are difficult to evaluate 

because the earlier load calculations were based on 

data collected at the Blossom Road monitoring site 

(adjusted for intervening surface-drainage area by a 

multiplier of 1.17). This estimation technique 

assumed that loading rates from the intervening area 

(the Ellison Park wetland) were comparable to those 

from the rest of the basin, whereas the present study 

(1990-96) indicated that the wetland can have a 

significant effect on the loads of certain constituents. 

For example, loads of total phosphorus and total 

suspended solids were greatly decreased by passage 

through the wetland; therefore, the estimated loads of 

these constituents, which were based on the adjusted 

Blossom Road values, probably exceeded the loads 

actually entering Irondequoit Bay by about 30 

percent for TP and about 50 percent for TSS (based 

on 1990-96 estimated loads, table 13). Loads of 

conservative constituents, such as chloride and 

sulfate, which did not appear to be strongly affected 

by the wetland, also might have been slightly 

overestimated, and the loads of ammonia nitrogen 

and orthophosphate, which increased during passage 

through the wetland, probably were underestimated 

by this calculation method.

Comparison of estimated annual loads 

transported by Irondequoit Creek to Irondequoit Bay 

during the 1980-81 study (Kappel and others, 1986) 

with those for 1984-88 (table 13), indicates a decrease 

in TKN loads (24 tons, 11 percent), and an increase in 

TP loads (2.9 tons, 14 percent) and TSS loads (9,300 

tons, 49 percent); chloride loads to Irondequoit Bay 

did not change substantially. Some of the differences 

between the two periods might be attributed to the 

differing lengths of time spanned by each study—the 

1980-81 data provide a 1-year “snapshot” of a 

dynamic system, whereas the 1984-88 values 

represent a 5-year period. A comparison of the 1984-

88 data with those from this study, which covered a 

similar time span, should provide a more reliable basis 

Table 13. Estimated average annual loads of selected chemical constituents entering Irondequoit Bay, 

Monroe County, N.Y.

[All values are in tons. Dash indicates no data available.]

Constituent

Values based on data from

Upstream end of wetland 

(Blossom Road)1

1Values are estimated loads computed for Irondequoit Creek at Blossom Road multiplied by 1.17 to account for the drainage area 

between Blossom Road and the mouth of Irondequoit Bay.

Downstream end of wetland

(Empire Boulevard)2

2Values are estimated loads computed for Irondequoit Creek at Empire Boulevard multiplied by 1.10 to account for the drainage area 

between Empire Boulevard and the mouth of Irondequoit Bay.

1980-813

3Data from Kappel and others (1986).

1984-884

4Data from Johnston and Sherwood (1996).

1990-965

5Data from this study, 1990-96. 

1990-965

Total nitrogen -- 383 322 289

Ammonia-plus-organic nitrogen 214 190 148 130

Ammonia nitrogen -- 6.33 3.03 5.24

Organic nitrogen -- 184 145 125

Nitrate plus nitrite -- 193 174 159

Total phosphorus 20.2 23.1 30.7 20.9

Orthophosphate -- 2.44 1.97 2.56

Total suspended solids 19,100 28,400 33,300 16,700

Volatile suspended solids -- 3,170 4,140 2,290

Nonvolatile suspended solids -- 25,200 29,200 14,400

Chloride 16,400 16,700 19,700 19,200

Sulfate -- 18,700 18,700 17,200
48 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

for discerning long-term temporal trends in 

constituent loads.

The chemical loads entering Irondequoit Bay as 

calculated from the 1990-96 data were computed two 

ways—the first calculation used the Blossom Road 

(wetland inflow) loads adjusted by the drainage-area 

multiplier of 1.17 (as was done for the earlier load 

estimates), and the second used the Empire Boulevard 

(wetland outflow) loads adjusted by a drainage-area 

multiplier of 1.10 (table 13). Comparison of these 

results confirms the potential error inherent in the use 

of the upstream (Blossom Road) data; that is, 

overestimation for constituents whose loads are 

significantly decreased by the wetland, especially total 

phosphorus, total nitrogen, and total suspended solids, 

and underestimation for those that are increased in the 

wetland, such as orthophosphate and ammonia 

nitrogen. The results indicate that (1) the loads of all 

major forms of nitrogen entering Irondequoit Bay have 

decreased since the 1980’s, (2) the loads of chloride 

have increased, (3) the loads of sulfate have remained 

about the same, and (4) the loads of ammonia nitrogen 

and orthophosphate entering the Ellison Park wetland 

have decreased, and (5) the loads of total phosphorus 

and suspended solids entering the wetland have 

increased. This increase in TP and TSS loads is 

possibly a result of increased erosion potential and 

transport capability of stormflows from an 

increasingly developed watershed and is substantiated 

by Young (1996), who documented an increasing rate 

of sediment accumulation in the floodplain of the 

lower Irondequoit Creek during the 20th century. The 

trend in loads of TP, TSS, NH3, and PO4 entering 

Irondequoit Bay since the 1980’s cannot be reliably 

defined because the removal of TP and TSS and 

generation of NH3 and PO4 in the wetland during the 

two earlier study periods are unknown. 

SUMMARY

A 6-year (1990-96) study of the Ellison Park 

wetland in Monroe County, N.Y., was conducted by 

the USGS, in cooperation with the Monroe County 

Department of Health, to document the effect of this 

predominantly cattail marsh on the chemical quality of 

Irondequoit Creek, which flows through it. This stream 

drains 151 mi2

 of mostly residential and urban land 

and is the main tributary to Irondequoit Bay. The 

wetland covers 423 acres and is mostly a palustrine 

persistent emergent marsh that is divided 

topographically into a southern and a northern part. 

Water levels in the wetland are controlled by the 

water-surface elevation of Irondequoit Bay and Lake 

Ontario. The seasonal periods of inundation averaged 

136 and 189 days in the southern and northern areas, 

respectively. The average maximum depth of 

inundation during these periods was 1.1 ft in the 

southern part and 1.5 ft in the northern part. 

Stream-discharge and water-quality data were 

collected at the inlet and outlet of the wetland, and the 

chemical loads were computed. Results indicate that 

the wetland decreased loads of particulate constituents 

and those chemicals associated with fine-grained 

sediment and organic matter, presumably through 

vegetative filtration, precipitation, and sedimentation 

and removal of adsorbed chemicals. Total-phosphorus 

and suspended-solids loads were decreased by 28 and 

47 percent, respectively, over the 6-year study period, 

and outflow concentrations of metals (zinc, lead, and 

cadmium) were significantly lower than inflow 

concentrations. Ammonia nitrogen and 

orthophosphate output loads exceeded their input 

loads (-38 and -84 percent removal efficiencies, 

respectively) but represented only 1 to 2 percent of 

total nitrogen loads and 6 to 12 percent of total 

phosphorus loads, respectively. The export of these 

constituents reflects generation through leaching and 

decomposition of organic matter and the diffusion of 

ammonia nitrogen from the reduced wetland soils. The 

loads of other constituents, such as organic nitrogen, 

nitrate plus nitrite, and sulfate, were decreased by the 

wetland, but the long-term (6-year) removal 

efficiencies were low (less than 8 percent). The 

wetland appeared to have little effect on conservative 

constituents, such as chloride and sulfate. Removal 

efficiencies for total phosphorus, orthophosphate, and, 

possibly, suspended solids, appeared to increase after a 

diversion- control modification in1994 that permitted 

additional stormwater to flow into the southeastern 

backwater area of the wetland to increase dispersal 

and detention time. Water temperatures were 

minimally affected by the wetland during winter, but 

the summer daily mean outflow temperatures were 

generally 1 to 2 °C warmer than the inflow 

temperatures. The summer differences between 

outflow and inflow temperatures usually decreased 

during the passage of storm runoff. 

The wetland sediments in open-water areas are 

predominantly silt sized and smaller and contained 

relatively small amounts of organic matter. The high 
49

percentage of fine-grained mineral particles and 

particulate forms of chemicals, such as suspended 

solids and phosphorus, that accumulated in these 

depositional areas are reflected in the wetland’s high 

removal efficiency for these constituents. The 

relatively low concentrations of organic carbon in the 

sediments reflect the lower rate of biomass 

accumulation from small submergent aquatic 

macrophytes here than would be expected in the 

cattail-covered areas. The sediments also contained 

high concentrations of trace metals, including barium, 

manganese, strontium, and zinc (each of which 

exceeded 200 ppm during this study), chromium, 

copper, lead, and vanadium; some polycyclic aromatic 

hydrocarbons, including chrysene, fluoranthene, 

phenanthrene, and pyrene; and persistent 

organochlorine pesticides (chlordane, dieldrin, DDT 

and its metabolic-degradation products, DDD and 

DDE) and polychlorinated biphenyls (PCB’s). 

Cattails, primarily Typha glauca, covered about 

63 percent of the wetland, attained a maximum height 

of 350 cm, a density of more than 30 shoots/m2, and a 

total biomass of over 5,600 g/m2, 46 percent of which 

was in above-ground tissues during the summer. 

Chemical analyses of cattail tissues indicated that the 

above-ground tissues contained greater 

concentrations of nitrogen and potassium (2.4 and 1.5 

percent by dry weight, respectively) than the belowground tissues and considerably lower concentrations 

of all other constituents than the below-ground 

tissues, except for phosphorus, molybdenum, and 

manganese, whose concentrations in above-ground 

tissue were similar to those in below-ground tissue. 

The concentrations of four elements exceeded those 

typically found in natural wetlands—manganese (417 

ppm) and sodium (3,600 ppm) in above-ground 

tissues; and aluminum (1,540 ppm), iron (15,400 

ppm), manganese (433 ppm), and sodium (10,000 

ppm) in below-ground tissues.

The wetland vegetation undoubtedly assimilated 

large quantities of nutrients during the growing season 

as indicated by the large biomass, but neither tissue 

production nor microbial metabolic processes 

appeared to appreciably affect the seasonal removalefficiency patterns of surface-water chemical loads. 

Presumably, internal cycling of nutrients in the 

sediments and organic detritus, combined with a 

summer increase in microbially mediated chemical 

transformations, obscured the effect of vegetative 

assimilation on surface-water loads. Additionally, 

confinement of most flows within the banks of 

Irondequoit Creek, which resulted in passage of storm 

water through the wetland with little dispersion or 

detention of water in the cattail and backwater areas of 

the wetland, diminished the wetland’s capability for 

water-quality improvement. Anaerobic conditions in 

the wetland soils probably were the reason for 

generation of ammonia nitrogen (through microbially 

mediated reduction of nitrate) and orthophosphate 

(through dissolution of cation-phosphate precipitates). 

The dominant factors in the chemical-removal 

efficiency of the wetland are (1) inflow-loading rates, 

(2) storage and release mechanisms of the sediments 

(sedimentation, adsorption, filtration, precipitation, 

dissolution, and resuspension), and (3) accretion and 

burial of organic matter. 

Measurements of chlorophyll_a concentrations 

and calculations of potential phosphorus 

concentrations made since the 1970’s indicate an 

improvement in the trophic state of Irondequoit Bay. 

Estimated annual loads of selected constituents 

indicated a decrease in loadings of all major forms of 

nitrogen, an increase in chloride loads, and little 

change in sulfate loads since 1980. Loads of total 

phosphorus and suspended solids entering the wetland 

increased during this period, possibly in response to 

increased stormflow volume and erosion from 

increased development in the watershed, but the trends 

of these loads entering Irondequoit Bay cannot be 

reliably defined because their removal efficiencies 

during the 1980’s are unknown. Loads of ammonia 

nitrogen and orthophosphate entering the wetland have 

decreased, but no trends on loads entering Irondequoit 

Bay can be stated because the generation of these 

constituents within the wetland was not taken into 

account by the earlier studies. Average annual loads 

(1990-96) of selected constituents entering 

Irondequoit Bay, as measured at the wetland outflow 

(Empire Boulevard) monitoring site and adjusted for 

the intervening surface-drainage area, were estimated 

to be 289 tons of total nitrogen (including 130 tons of 

ammonia-plus-organic nitrogen and 159 tons of 

nitrate-plus-nitrite nitrogen), 21 tons of total 

phosphorus, 16,700 tons of total suspended solids, 

19,200 tons of dissolved chloride, and 17,200 tons of 

sulfate.
50 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

REFERENCES CITED

Adamus, P.R., and Stockwell, L.T., 1983, A method for 

wetland functional assessment—v. I, critical review 

and evaluation concepts: U.S. Department of 

Transportation, Federal Highway Administration 

Report FHWA-IP-82-23, 176 p.

American Public Health Association, American Water 

Works Association, Water Environment Federation, 

1995, Standard methods for examination of water and 

wastewater, 19th ed.: Washington, D.C., American 

Public Health Association, paginated by section.

Andrews, N.J., and Pratt, D.C., 1978, The potential of 

cattails (Typha spp.) as an energy source—Productivity 

in managed stands: Journal of the Minnesota Academy 

of Science, v. 44, p. 5-8.

Andrle, R.F., and Carroll, J.R., 1988, The atlas of breeding 

birds in New York State: Ithaca, N.Y., Cornell 

University Press, 551 p.

Bernard, J.M., and Seischab, F.K., 1991, Flora and 

vegetation of the Irondequoit Creek and Buttonwood 

Creek wetlands: Report submitted to U.S. Geological 

Survey, Ithaca, N.Y., in fulfillment of contractual 

agreement, 49 p.

__________, 1997, Vegetation of the wetland near the 

mouth of Irondequoit Creek, 1996: Report submitted to 

U.S. Geological Survey, Ithaca, N.Y., in fulfillment of 

contractual agreement, 23 p.

Bernard, J.M., and Gorham, E., 1978, Life history aspects 

of primary production in sedge wetlands, in Good, 

R.E., Whigham, D.F., and Simpson, R.L., (eds.), 

Freshwater wetlands—production processes and 

management potential: Academic Press, N.Y., p. 39-

51.

Bernard, J.M., and Fitz, M. L., 1979, Seasonal changes in 

aboveground primary production and nutrient contents 

in a central New York Typha glauca ecosystem: 

Bulletin Torrey Botanical Club, v. 106, p. 37-40.

Boar, R.R., 1996, Temporal variations in nitrogen content of 

Phragmites australis (Cav.) Trin. ex Steud. from a 

shallow fertile lake: Aquatic Botany, v. 55, p. 171-181.

Bouldin, D.R., Bernard, J.M., and Lauve, T.E., 1993, 

Leachate treatment system using constructed wetlands, 

Town of Fenton sanitary landfill, Broome County, N.Y. 

Final Report to New York State Energy Research and 

Development Authority No. 94-2.

Boyd, C.E., 1970, Production, mineral accumulation and 

pigment concentrations in Typha latifolia and Scirpus 

americanus: Ecology, v. 51, p. 285-290.

__________, 1971, Further studies on productivity, nutrient 

and pigment relationships in Typha latifolia

populations: Bulletin of the Torrey Botanical Club, 

v. 98, no. 3, p. 144-150.

Boyd, C.E., and Hess, L.W., 1970, Factors influencing shoot 

production and mineral nutrient levels in Typha 

latifolia: Ecology, v. 51, no. 2, p. 296-300.

Bray, J.R., 1960, The chlorophyll content of some native 

and managed plant communities in central Minnesota: 

Canadian Journal of Botany, v. 38, p. 313-333.

Bray, J.R., Lawrence, D.B., and Pearson, L.C., 1959, 

Primary production in some Minnesota terrestrial 

communities: Oikos, v. 10, p. 38-49.

Bubeck, R.C., and Burton, R.S., 1989, Changes in chloride 

concentrations, mixing patterns, and stratification 

characteristics of Irondequoit Bay, Monroe County, 

New York, after decreased use of road-deicing salts, 

1974-1984: U.S. Geological Survey Water-Resources 

Investigations Report 87-4223, 52 p.

Buchanan, T.J., and Somers, W.P., 1968, Stage measurement 

at gaging stations: U.S. Geological Survey Techniques 

of Water-Resources Investigations, book 3, chap. A7, 

28 p.

__________, 1969, Discharge measurement at gaging 

stations: U.S. Geological Survey Techniques of WaterResources Investigations, book 3, chap. A8, 65 p.

Carter, R.W., and Davidian, J., 1968, General procedure for 

gaging streams: U.S. Geological Survey Techniques of 

Water-Resources Investigations, book 3, chap. A6, 

13 p.

Cohn, T.A., 1988, Adjusted maximum likelihood estimation 

of the moments of lognormal populations from type I 

censored samples: U.S. Geological Survey Open-File 

Report 88-350, 34 p.

Cohn, T.A., 1995, Recent advances in statistical methods for 

the estimation of sediment and nutrient transport in 

rivers: U.S. National Report to International Union of 

Geodesy and Geophysics 1991-1994, Reviews of 

Geophysics, Supplement, p. 1117-1123.

Cohn, T.A., DeLong, L.L., Gilroy, E.J., Hirsch, R.M., and 

Wells, D.K., 1989, Estimating constituent loads: Water 

Resources Research, v. 25, no. 5, p. 937-942.

Cohn, T.A., Caulder, D.L., Gilroy, E.J., Zynjuk, L.D., and 

Summers, R.M., 1992, The validity of a simple 

statistical model for estimating fluvial constituent 

loads—an empirical study involving nutrient loads 

entering Chesapeake Bay: Water Resources Research, 

v. 28, no. 9, p. 2353-2363

Cowardin, L.M., Carter, V., Golet, F.C., and LaRoe, E.T., 

1979, Classification of wetlands and deepwater 

habitats of the United States: U.S. Fish and Wildlife 

Service, FWS/OBS-79/31, 131 p.

Coon, W.F., 1997, Hydrology, biology, and sedimentology 

of Ellison Park wetland at the mouth of Irondequoit 

Creek near Rochester, New York: U.S. Geological 

Survey Water-Resources Investigations Report 96-

4269, 41 p.

Davido, R.L., and Conway, T.E., 1989, Nitrification and 

denitrification at the Iselin marsh/pond/meadow 
51

facility: in Hammer, D.A., Constructed wetlands for 

wastewater treatment—municipal, industrial and 

agricultural: Chelsea, Mich., Lewis Publishers, p. 477-

483.

DeGaspari, C., and Bannister, T.T., 1983, Survey of the 

Irondequoit Creek wetlands—possible effects of shortterm impoundment of storm water behind a proposed 

flow-regulating structure at the Narrows: Rochester, 

N.Y., Monroe County Department of Health, 

Irondequoit Bay Report No. 13, 21 p.

Diment, W.H., Bubeck, R.C., and Deck, B.L., 1974, Effects 

of deicing salts on the waters of the Irondequoit Bay 

drainage basin, Monroe County, New York, in Coogan, 

A.H., ed., Fourth Symposium on Salt: Cleveland, Ohio, 

Northern Ohio Geological Society, v. 1, p. 391-405.

Durum, W.H., Hem, J.D., and Heidel, S.G., 1971, 

Reconnaissance of selected minor elements in surface 

waters of the United States, October 1970: U.S. 

Geological Survey Circular 643, 49 p.

Fishman, M.J., and Friedman, L.C., (eds.), 1989, Methods 

for the determination of inorganic substances in water 

and fluvial sediments: U.S. Geological Survey 

Techniques of Water-Resources Investigations, book 5, 

chap. A1, 545 p.

Gadbois, L.E., 1989, Environmental feasibility of using 

wetlands to treat runoff pollution: U.S. Navy, Naval 

Ocean Systems Center Technical Report 1321, 29 p.

Gehrels, J., and Mulamoottil, G., 1989, The transformation 

and export of phosphorus from wetlands: Hydrological 

Processes, v. 3, p. 365-370.

Harbison, K.G., 1974, Summary of the effects on water 

quality of the marshlands located in the lower 

Irondequoit valley: Rochester, N.Y., Monroe County 

Environmental Management Council, 4 p.

Hem, J.D., 1989, Study and interpretation of the chemical 

characteristics of natural water, 3rd ed.: U.S. 

Geological Survey Water-Supply Paper 2254, 263 p.

Hickok, E.A., 1978, Wetlands and organic soils for the 

control of urban stormwater, in Lake Restoration, 

Proceedings of a National Conference, Minneapolis, 

Minn.: U.S. Environmental Protection Agency Report 

440/5-79-00, p. 153-158.

Hickok, E.A., Hannaman, M.C., and Wenck, N.C., 1977, 

Urban runoff treatment methods, volume I, Nonstructural wetland treatment: U.S. Environmental 

Protection Agency Report 600/2-77-217, 121 p.

Hornlein, J.F., Szabo, C.O., Zajd, H.J., Jr., and Mulks, R.L, 

1997, Water-Resources Data, New York, Water year 

1996, volume 3--Western New York: U.S. Geological 

Survey Water-Data Report NY-96-3, 284 p.

Hutchinson, G.E., 1975, A treatise on limnology, volume 

III, limnological botany: New York, John Wiley, 660 p.

Johnston, Carol A., 1991, Sediment and nutrient retention 

by freshwater wetlands—Effects on surface water 

quality: Critical Reviews in Environmental Control, 

v. 21 (5,6), p. 491-565.

Johnston, W.H., and Sherwood, D.A., 1996, Water 

Resources of Monroe County, New York, water years 

1984-88, with emphasis on water quality in the 

Irondequoit Creek basin, Part 2—Atmospheric 

deposition, ground water, streamflow, trends in water 

quality, and chemical loads to Irondequoit Bay: U.S. 

Geological Survey Water-Resources Investigations 

Report 96-4054, 84 p.

Kadlec, J.A., 1987, Nutrient dynamics in wetlands, in

Reddy, K.R, and Smith, W.H. (eds.), Aquatic plants for 

water treatment and resource recovery: Orlando, Fla., 

Magnolia Publishing Co., p. 393-419.

Kadlec, R.H., and Knight, R.L., 1996, Treatment wetlands: 

Boca Raton, Lewis Publishers, 893 p.

Kappel, W.M., Yager, R.M., and Zarriello, P.J., 1986, 

Quantity and quality of urban storm runoff in the 

Irondequoit Creek basin near Rochester, New York, 

Part 2—Quality of storm runoff and atmospheric 

deposition, runoff-quality modeling, and potential of 

wetlands for sediment and nutrient retention: U.S. 

Geological Survey Water-Resources Investigations 

Report 85-4113, 93 p.

Kappel, W.M., and Young, R.A., 1989, Glacial history and 

geohydrology of the Irondequoit Creek valley, Monroe 

County, New York: U.S. Geological Survey WaterResources Investigations Report 88-4145, 34 p.

Kennedy, E.J., 1984, Discharge ratings at gaging stations: 

U.S. Geological Survey Techniques of WaterResources Investigations, book 3, chap. A10, 59 p.

Klopatek, J., 1978, Nutrient dynamics of freshwater riverine 

marshes and the role of emergent macrophytes, in

Good, R.E., Whigham, D.F., and Simpson, R.L., (eds), 

Freshwater Wetlands—Ecological processes and 

management potential: New York, Academic Press, 

p. 195-216.

Laenen, A., 1985, Acoustic velocity meter systems: U.S. 

Geological Survey Techniques of Water-Resources 

Investigations, book 3, chap. A17, 38 p.

Livingston, E.H., 1989, Use of wetlands for 

urbanstormwater management, in Hammer, D.A., 

Constructed wetlands for wastewater 

treatment—municipal, industrial, and agricultural: 

Chelsea, Mich., Lewis Publishers, p. 253-262.

Mason, C.R., and Bryant, R.J., 1975, Production, nutrient 

content, and decomposition of Phragmites communis 

Trin. and Typha angustifolia L.: Journal of Ecology, 

v. 63, p. 71-95.

McNaughton, S.J., 1966, Ecotype function in the Typha

community-type: Ecological Monographs, v. 36, no. 4, 

p. 297-325.

Miller, D.J., and Ringler, N.H., 1992, Effects of storm water 

retention on the animal community of the upper and 

lower wetlands of Irondequoit Creek, Rochester, New 
52 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

York: Report submitted to U.S. Geological Survey, 

Ithaca, N.Y., in fulfillment of contractual agreement, 

50 p.

Mitsch, W.J., and Gosselink, J.G., 1986, Wetlands: New 

York, VanNostrand Reinhold, 539 p.

National Climatic Data Center, 1996, Local climatological 

data, 1996 annual summary with comparative data, 

Rochester, New York: Asheville, N.C., National 

Climatic Data Center, 8 p.

Northeast Regional Climate Center, 1996, New York 

Climate-June1996: Ithaca, N.Y., Northeast Regional 

Climate Center, v. 96, no. 6, 13 p.

O’Brien and Gere, 1983, Nationwide urban runoff program, 

Irondequoit basin study, final report: Rochester, N.Y., 

Irondequoit Bay Pure Waters District, 164 p.

Pixley, E.Y., 1982, Rochester Committee for Scientific 

Information—Studies of pollution control in a 

lakefront community, 1964-81, Rochester Academy of 

Science, Proceedings: Rochester N.Y., Rochester 

Academy of Science, v. 14, no. 2, 243 p.

Prentki, R.T., Gustafson, T.D., and Adams, M.S., 1978, 

Nutrient movements in lakeshore marshes, in Good, 

R.E., Whigham, D.F., and Simpson, R.L., (eds), 

Freshwater Wetlands— Ecological processes and 

management potential, New York, Academic Press, 

p. 169-195.

Radtke, D. B., 1997, Bottom-material samples: U.S. 

Geological Survey Techniques of Water-Resources 

Investigations, National Field Manual for the 

Collection of Water-Quality Data, book 9, chap. A8, 

48 p

Rantz, S.E., and others, 1982, Measurement and 

computation of streamflow, v. 1, Measurement of stage 

and discharge; v. 2, Computation of discharge: U.S. 

Geological Survey Water-Supply Paper 2175, 631 p.

SAS Institute, Inc., 1989, SAS/STAT users guide, version 6, 

4th ed, v. 2, Cary, NC: SAS Institute, Inc., 846 p.

SAS Institute, Inc., 1990, SAS procedures guide, version 6, 

3rd ed, Cary, NC: SAS Institute, Inc., 705 p.

Schroeder, R.A., 1985, Sediment accumulation rates in 

Irondequoit Bay, New York, based on lead-210 and 

cesium-137 geochronology: Northeastern 

Environmental Science, v. 4, no. 1, p. 23-29.

Shelton, L.R., and Capel, P.D., 1994, Guidelines for 

collecting and processing samples of streambed 

sediment for analysis of trace elements and organic 

contaminants for the National Water-Quality 

Assessment Program: U.S. Geological Survey OpenFile Report 94-458, 20 p.

Sherwood, D.A., 1997, Water resources of Monroe County, 

New York, water years 1989-93, with emphasis on 

water quality in the Irondequoit Creek basin, Part 

1—Water-Resources Data: U.S. Geological Survey 

Open-File Report 97-587, 219 p.

Smith, J.A., Witkowski, P.J., and Fusillo, T.V., 1988, 

Manmade organic compounds in the surface waters of 

the United States - a review of current understanding: 

U.S. Geological Survey Circular 1007, 92 p.

Strecker, E.W., Kersnar, J.M., Driscoll, E.D., and Horner, 

R.R., 1992, The use of wetlands for controlling 

stormwater pollution: Washington, D.C., The Terrene 

Institute, 65 p.

Timme, P.J., 1995, National Water Quality Laboratory 1995 

services catalog: U.S. Geological Survey Open-file 

Report 95-352, 120 p.

U.S. Environmental Protection Agency, 1983, Results of the 

Nationwide Urban Runoff Program, Executive 

Summary: National Technical Information Service, 

Accession No. PB84-185545, 24 p.

__________, 1993, Natural wetlands and urban 

stormwater—potential impacts and management: U.S. 

Environmental Protection Agency Report 843-R-001, 

76 p.

U.S. Soil Conservation Service, 1985, Soils—hydric soils of 

the United States: Soil Conservation Service Natural 

Bulletin no. 430-5-9, 3 p.

Van der Valk, A.G., and Davis, C.B., 1978, Primary 

production of prairie glacial marshes: in Good, R.E., 

Whigham, D.F., and Simpson, R.L., (eds.), Freshwater 

wetlands—production processes and management 

potential: Academic Press, N.Y., p. 21-37.

Vitosh, M.L., Warncke, D.D., and Lucas, R.E., 1973, 

Secondary and micronutrients for vegetables and field 

crops: Extension Bulletin E-486, Cooperative 

Extension Service, Michigan State University, East 

Lansing, in Donahue, R.L., Miller, R.W., and 

Shickluna, J.C., 1977, Soils - an introduction to soils 

and plant growth: Englewood Cliffs, N.J., PrenticeHall, 626 p.

Vollenweider, R.A., 1976, Advances in defining critical 

loading levels for phosphorus in lake eutrophication: 

Memorie dell’Istituto Italiano di Idrobiologia, v. 33, 

p. 53-83.

Wershaw, R.L., Fishman, M.J., Grabbe, R.R., and Lowe, 

L.E. (eds.), 1987, Methods for the determination of 

organic substances in water and fluvial sediments: U.S. 

Geological Survey Techniques of Water-Resources 

Investigations, book 5, chap. A3, 80 p.

Whigham, D.F., McCormick, J., Good, R.E., and Simpson, 

R.L., 1978, Biomass and primary production in 

freshwater tidal wetlands of the Middle Atlantic coast: 

in Good, R.E., Whigham, D.F., and Simpson, R.L., 

(eds.), Freshwater wetlands—production processes and 

management potential: Academic Press, N.Y., p. 3-20.

Windholz, Martha, (Ed.), 1983, The Merck index, an 

encyclopedia of chemicals, drugs, and biologicals, 

10th ed.: Rahway, N.J., Merck and Co., Inc., 1463 p. 

plus appendixes.
53

Woodward-Clyde Consultants, 1994, Contribution of heavy 

metals to storm water from automotive disc brake pad 

wear: Oakland, Calif., Woodward-Clyde Consultants, 

38 p.

__________, 1997, Metals control measures plan (v. I) and 

evaluation of nine metals of concern (v. II): Oakland, 

Calif., Woodward-Clyde Consultants, paginated by 

section.

Yager, R.M., Zarriello, P.J., and Kappel, W.M., 1985, 

Geohydrology of the Irondequoit Creek basin near 

Rochester, New York: U.S. Geological Survey WaterResources Investigations Report 84-4259, 

scale 1:24,000, 6 sheets.

Young, R.A., 1996, Historic and recent sedimentation rates 

and projections from radiocarbon samples, Irondequoit 

Creek floodplain study, Ellison Park, Monroe County, 

NY: Report submitted to Monroe County Department 

of Health, Rochester, N.Y., 13 p.

Young, R., and Burton, R., 1993, Bluff erosion along 

Irondequoit Creek in Linear Park: Rochester 

Committee for Scientific Information, Bulletin 315, 

6 p.

Zarriello, P.J., Harding, W.E., Yager, R.M., and Kappel, 

W.M., 1985, Quantity and quality of storm runoff in 

the Irondequoit Creek basin near Rochester, New York, 

Part 1—Data-collection network and methods, qualityassurance program, and description of available data: 

U.S. Geological Survey Open-File Report 84-610, 

44 p.
54 Effects of a Cattail Wetland on Water Quality of Irondequoit creek near Rochester, New York Appendix 1. Selected chemical analyses of water samples from Irondequoit Creek above Blossom Road and at Empire Boulevard (E

inflow and outflow sites), Monroe County, N.Y., 1990-96 [yr-mo-d, year, month, day; Q, mean discharge; ft3/s, cubic feet per second; Cd, total cadmium; Cu, total recoverable copper; Pb, total recoverable le

total organic carbon; BOD5, 5-day biochemical oxygen demand; COD, chemical oxygen demand; Alk, alkalinity as calcium carbonate; Spec. Cond

microsiemens per centimeter. Dash indicates no data; <, less than.]

Beginning of

sampling period

End of sampling

period Q 

(ft3/s)

Metals (micrograms per liter) Physical properties (m

Yr-mo-d Time Yr-mo-d Time Cd Cu Pb Zn TOC BOD 

5 

A. Irondequoit Creek above Blossom Road, Rochester, N.Y. (station 0423205010)

1990-01-03 1915 90-01-05 0915 170 < 1 50 < 5 80 -- -- 1990-01-18 0115 90-01-19 0915 350 < 1 60 82 180 -- -- 1990-02-08 1015 90-02-09 0515 340 1 40 13 70 -- -- 1990-02-09 0615 90-02-12 0915 540 < 1 50 32 120 -- -- 1990-02-22 1535 90-02-23 0835 500 3 50 30 120 -- -- 1991-03-02 1005 91-03-04 0305 440 2 90 50 240 -- -- 1991-03-07 1105 91-03-08 1005 560 1 70 84 260 -- -- 1991-03-08 1320 -- -- 410 < 5 < 10 < 5 40 -- -- 1991-03-11 1140 -- -- 210 < 1 < 10 7 < 40 -- -- 1992-02-18 1020 92-02-19 1320 140 < 1 120 6 60 -- -- 1992-02-18 1055 92-02-19 1355 144 < 1 60 < 5 40 -- -- 1992-02-19 1420 92-02-20 0820 190 < 1 50 20 40 -- -- 1992-02-19 1455 92-02-20 0855 186 < 1 30 9 40 -- -- 1992-02-20 0915 92-02-22 2015 160 < 1 60 5 40 -- -- 1992-02-20 0940 92-02-22 2040 160 < 1 20 -- 50 -- -- 1992-02-22 2115 92-02-24 0815 190 < 1 60 6 40 -- -- 1992-02-22 2140 92-02-24 0840 188 < 1 < 20 < 5 60 -- -- 1992-03-26 0915 92-03-27 2015 610 1 90 56 290 -- -- 1992-03-27 2115 92-03-30 0815 850 < 1 90 15 140 -- -- 1992-10-09 1330 92-10-10 0430 299 1 70 16 110 -- -- 1992-10-10 0530 92-10-13 1030 160 < 1 40 6 60 -- -- 1992-11-02 1030 92-11-03 0930 312 1 50 7 50 -- -- 1992-11-03 1030 92-11-05 0430 342 3 100 10 40 -- -- 1992-12-10 1100 92-12-14 1000 120 < 1 60 < 5 < 40 -- -- 1992-12-14 1205 92-12-16 0505 140 < 1 80 < 5 40 -- -- 1992-12-16 0605 92-12-17 1005 286 < 1 70 6 60 -- -- 1992-12-17 1100 92-12-18 0200 498 < 1 60 -- 80 -- -- 1992-12-18 0300 92-12-21 1000 439 < 1 50 -- 70 -- -- 
Appendix 1 55

A. Irondequoit Creek above Blossom Road, Rochester, N.Y. (station 0423205010, cont.)

1993-02-04 1215 -- -- 147 < 1 < 50 < 5 < 40 -- -- 1993-03-22 0920 93-03-25 0820 307 < 1 100 5 50 -- -- 1993-03-25 0915 93-03-29 0815 721 < 1 70 6 60 -- -- 1993-03-29 0925 93-03-30 0025 1270 < 1 120 20 80 -- < 2.00 1993-03-29 0925 93-03-31 0025 1360 -- 120 -- 80 -- -- 1993-04-01 0945 -- -- 1400 1 20 8 70 -- < 2.00 1993-04-05 0935 93-04-08 0835 482 < 1 40 12 60 4.60 < 2.00 1993-05-24 0900 93-05-28 0800 87 < 1 60 8 60 3.80 3.00 1993-06-05 0525 93-06-05 2025 318 < 1 110 80 370 6.60 12.3 1993-06-05 2125 93-06-06 1225 238 2 90 18 180 5.90 9.70 1993-09-03 0035 93-09-04 0035 159 < 1 100 48 270 6.10 7.20 1993-09-04 0135 93-09-06 0735 71 < 1 70 22 130 4.60 < 4.00 1993-11-24 1005 93-11-27 0705 68 < 1 -- 6 50 3.50 < 2.00 1993-11-27 0805 93-11-28 1305 431 < 1 -- 20 180 4.90 3.50 1993-11-28 1405 93-11-29 0905 580 < 1 -- 16 110 6.70 4.50 1993-11-29 0905 93-12-02 0805 203 < 1 -- < 5 -- 6.60 2.30 1994-01-14 0950 94-01-18 0850 58 < 1 -- < 5 -- -- 2.00 1994-02-18 0920 94-02-21 0820 320 < 1 -- 11 -- -- 2.30 1994-02-21 0920 94-02-22 0820 818 < 1 -- 7 -- -- 3.30 1994-02-22 0905 94-02-24 0905 392 < 1 -- 6 -- -- < 2.00 1994-03-21 0920 94-03-23 0220 735 1 50 15 -- -- 2.20 1994-03-23 0320 94-03-24 0820 959 2 40 9 -- -- 2.10 1994-03-24 0930 94-03-24 2030 724 1 30 5 -- -- -- 1994-04-12 1820 94-04-14 0820 780 -- 30 12 -- -- 3.60 1994-04-14 0900 94-04-18 0800 383 2 20 11 -- -- 2.30 1994-06-09 0920 94-06-13 0820 65 -- 58 2 -- -- -- 1994-08-13 0925 94-08-14 1225 148 < 1 40 10 -- -- 2.70 1994-08-14 1325 94-08-15 0825 168 < 1 50 13 -- -- 3.60 1994-08-15 0900 94-08-18 0800 68 < 1 40 6 < 40 -- < 2.00 1994-09-19 0915 94-09-22 0815 52 < 1 30 < 5 < 40 -- 2.10 1994-12-05 0940 94-12-06 0240 264 2 28 -- -- -- < 2.00 

Beginning of

sampling period

End of sampling

period Q 

(ft3/s)

Metals (micrograms per liter) Physical properties (m

Yr-mo-d Time Yr-mo-d Time Cd Cu Pb Zn TOC BOD 

5 

Appendix 1. Selected chemical analyses of water samples from Irondequoit Creek above Blossom Road and at Empire Boulevard (Einflow and outflow sites), Monroe County, N.Y., 1990-96 (continued)
56 Effects of a Cattail Wetland on Water Quality of Irondequoit creek near Rochester, New York A. Irondequoit Creek above Blossom Road, Rochester, N.Y. (station 0423205010, cont.) 1994-12-06 0340 94-12-07 2040 190 2 27 -- -- -- < 2.00 

1994-12-08 0915 94-12-09 1615 138 < 1 30 5 40 -- < 2.00 1994-12-30 0745 94-12-31 1845 57 < 1 40 < 5 < 40 -- 2.00 1995-02-09 0930 95-02-13 0830 60 < 1 < 50 < 5 < 40 -- < 2.00 1995-03-06 1645 95-03-08 1250 283 1 20 < 5 40 -- 2.00 1995-03-08 1350 95-03-09 0750 322 < 1 20 < 5 < 40 -- 2.00 1995-03-09 0815 95-03-13 0715 222 < 1 20 < 5 < 40 -- < 2.00 1995-03-13 0930 95-03-16 0730 187 < 1 20 2 50 -- < 2.00 1995-03-16 0805 95-03-20 0705 148 1 20 < 2 < 40 -- < 2.00 1995-05-08 1125 95-05-09 2225 52 < 1 < 20 1.7 < 40 -- < 2.00 1995-05-09 2325 95-05-11 1025 94 < 1 < 20 3 < 40 -- < 2.00 1995-08-21 1245 95-08-24 1045 30 < 1 20 < 5 30 2.3 < 2.00 1995-10-21 0315 95-10-21 1815 1030 < 1 30 34 220 -- < 4.00 1995-10-21 1915 95-10-23 1015 551 < 1 30 12 70 -- < 2.00 1995-12-11 1200 95-12-14 1100 58 < 1 20 < 5 20 6.3 < 2.00 1996-01-16 1045 96-01-18 0945 189 < 1 20 7 55 7.20 < 2.00 1996-01-18 1025 96-01-19 2125 933 1 70 31 220 7.10 8.20 1996-01-19 2225 96-01-22 0525 777 2 80 34 360 10.1 14.0 1996-01-22 1125 96-01-25 1025 336 < 1 40 10 45 7.60 2.00 1996-01-25 1040 96-01-29 0940 268 < 1 30 13 35 5.80 < 2.00 1996-01-29 1100 96-02-01 1000 145 < 1 20 8 30 5.70 < 2.00 1996-02-01 1045 96-02-05 0945 86 < 1 20 8 25 5.20 < 2.00 1996-04-12 1440 96-04-14 0140 475 < 1 50 < 5 30 5.60 2.30 1996-04-14 0240 96-04-15 0940 866 < 1 50 9 40 11.0 2.90 1996-04-14 1100 96-04-17 0820 287 < 1 30 < 5 20 6.20 < 2.00 1996-04-18 1045 96-04-22 0945 229 < 1 20 < 5 10 -- -- 

Beginning of

sampling period

End of sampling

period Q 

(ft3/s)

Metals (micrograms per liter) Physical properties (m

Yr-mo-d Time Yr-mo-d Time Cd Cu Pb Zn TOC BOD 

5 

Appendix 1. Selected chemical analyses of water samples from Irondequoit Creek above Blossom Road and at Empire Boulevard (Einflow and outflow sites), Monroe County, N.Y., 1990-96 (continued)
Appendix 1 57

B. Irondequoit Creek at Empire Boulevard, Rochester, N.Y. (station 0423205025)

1991-03-02 1825 91-03-04 0925 438 1 80 39 150 -- -- 1991-03-06 1110 91-03-08 1010 659 < 1 70 13 90 -- -- 1991-03-08 1015 91-03-11 0915 291 < 1 50 8 60 -- -- 1991-03-12 0955 -- -- 175 < 1 < 10 < 5 < 40 -- -- 1992-02-14 1015 92-02-15 1715 72 < 1 60 < 5 -- -- -- 1992-02-15 1815 92-02-16 1715 136 < 1 70 6 -- -- -- 1992-02-16 1815 92-02-17 1915 143 < 1 70 < 5 -- -- -- 1992-02-18 1130 92-02-19 1430 136 < 1 70 7 -- -- -- 1992-02-19 1530 92-02-20 0930 160 < 1 70 7 -- -- -- 1992-02-20 1015 92-02-22 2115 148 < 1 60 5 < 40 -- -- 1992-02-22 2215 92-02-24 0915 176 < 1 50 < 5 < 40 -- -- 1992-03-26 1000 92-03-28 0400 714 1 90 37 120 -- -- 1992-03-28 0500 92-03-30 0900 1010 1 < 50 14 90 -- -- 1992-10-09 0945 92-10-10 0845 256 < 1 40 8 70 -- -- 1992-10-10 0945 92-10-13 0845 167 < 1 40 6 60 -- -- 1992-11-02 1010 92-11-03 2110 316 1 40 9 70 -- -- 1992-11-03 2210 92-11-05 0910 336 1 40 7 70 -- -- 1992-12-10 1025 92-12-14 0925 134 < 1 60 < 5 40 -- -- 1992-12-14 1125 92-12-16 0725 147 < 1 80 < 5 30 -- -- 1992-12-16 0825 92-12-17 0925 276 < 1 90 < 5 50 -- -- 1992-12-17 1025 92-12-18 0125 437 < 1 70 -- 110 -- -- 1992-12-18 0225 92-12-21 0925 461 < 1 70 -- 80 -- -- 1993-02-01 1100 93-02-04 1000 162 < 1 < 50 8 < 40 -- -- 1993-03-22 0950 93-03-25 0850 325 < 1 70 < 5 40 -- -- 1993-03-25 0950 93-03-29 0850 668 < 1 90 < 5 110 -- -- 1993-03-29 1005 93-03-31 0405 1260 < 1 100 6 65 -- < 2.00 1993-03-29 1005 93-03-31 0605 1250 < 1 80 7 50 -- < 2.00 1993-03-31 0705 93-04-01 0905 1360 < 1 70 10 60 -- < 2.00 1993-04-01 1030 93-04-03 0130 1760 < 1 90 10 70 5.00 < 2.00 1993-04-03 0230 93-04-05 0830 1150 < 1 90 5 60 4.40 < 2.00 1993-04-06 1015 93-04-06 1045 496 < 1 70 5 70 4.40 < 2.00 1993-04-06 1045 93-04-08 0945 442 < 1 80 8 70 4.30 < 2.00 

Beginning of

sampling period

End of sampling

period Q 

(ft3/s)

Metals (micrograms per liter) Physical properties (m

Yr-mo-d Time Yr-mo-d Time Cd Cu Pb Zn TOC BOD 

5 

Appendix 1. Selected chemical analyses of water samples from Irondequoit Creek above Blossom Road and at Empire Boulevard (E

inflow and outflow sites), Monroe County, N.Y., 1990-96 (continued)
58 Effects of a Cattail Wetland on Water Quality of Irondequoit creek near Rochester, New York B. Irondequoit Creek at Empire Boulevard, Rochester, N.Y. (station 0423205025, cont.) 1993-05-24 0925 93-05-28 0825 68 1 70 5 < 40 4.90 < 2.00 

1993-06-05 0545 93-06-06 0045 275 -- 60 9 110 6.50 2.20 1993-06-06 0145 93-06-07 0845 174 < 1 60 12 90 5.60 5.30 1993-09-02 2015 93-09-04 0615 150 < 1 30 6 80 4.30 < 2.00 1993-09-04 0715 93-09-07 0915 106 < 1 40 12 60 4.50 < 2.00 1993-11-24 1030 93-11-27 1230 69 < 1 -- < 5 40 3.50 < 2.00 1993-11-27 1330 93-11-28 1330 307 < 1 -- 13 60 5.00 < 4.00 1993-11-28 1430 93-11-29 0930 591 < 1 -- 11 80 7.40 < 4.00 1993-11-29 1000 93-12-02 0900 244 < 1 -- < 5 -- 6.70 2.30 1994-01-14 1030 94-01-18 0930 64 < 1 -- < 5 -- -- < 2.00 1994-02-18 1025 94-02-21 1325 362 < 1 -- 9 -- -- 4.90 1994-02-21 1425 94-02-22 0925 976 < 1 -- 6 -- -- 2.90 1994-02-22 0945 94-02-24 0845 574 < 1 -- 5 -- -- < 2.00 1994-03-21 0950 94-03-23 0550 582 1 40 12 -- -- 2.60 1994-03-23 0650 94-03-24 0850 919 1 30 7 -- -- 2.20 1994-03-24 1000 94-03-27 0500 580 1 30 5 -- -- -- 1994-04-12 1555 94-04-14 0855 563 -- 20 8 -- -- 2.50 1994-04-14 0930 94-04-18 0830 438 < 1 30 -- -- -- 2.70 1994-06-09 1035 94-06-13 0835 67 < 1 29 3 -- -- -- 1994-08-13 0955 94-08-14 1655 133 < 1 30 10 -- -- < 2.00 1994-08-14 1755 94-08-15 0855 180 < 1 40 5 -- -- < 2.00 1994-08-15 0930 94-08-18 0830 70 < 1 30 5 < 40 -- < 2.00 1994-12-05 1005 94-12-06 0305 259 1 21 -- -- -- < 2.00 1994-12-06 0405 94-12-08 0905 192 < 1 22 -- -- -- < 2.00 1994-12-08 0945 94-12-09 2045 135 < 1 40 < 5 < 40 -- 2.00 1994-12-30 0815 94-12-31 1915 54 -- 30 < 5 < 40 -- 2.00 

Beginning of

sampling period

End of sampling

period Q 

(ft3/s)

Metals (micrograms per liter) Physical properties (m

Yr-mo-d Time Yr-mo-d Time Cd Cu Pb Zn TOC BOD 

5 

Appendix 1. Selected chemical analyses of water samples from Irondequoit Creek above Blossom Road and at Empire Boulevard (E

inflow and outflow sites), Monroe County, N.Y., 1990-96 (continued)
Appendix 1 59

B. Irondequoit Creek at Empire Boulevard, Rochester, N.Y. (station 0423205025, cont.)

1995-02-09 1000 95-02-13 0900 60 < 1 < 50 < 5 < 40 -- < 2.00 1995-03-06 1025 95-03-08 0815 273 < 1 20 < 5 < 40 -- < 2.00 1995-03-08 0915 95-03-09 0815 348 < 1 20 < 5 < 40 -- < 2.00 1995-03-09 0845 95-03-13 0745 237 < 1 20 < 5 < 40 -- < 2.00 1995-03-13 0950 95-03-16 0750 198 < 1 20 2 < 40 -- < 2.00 1995-03-16 0835 95-03-20 0735 147 1 20 3 40 -- < 2.00 1995-05-08 1100 95-05-09 2200 52 < 1 < 20 3.3 < 40 -- < 2.00 1995-05-09 2300 95-05-11 1000 87 < 1 < 20 4 40 -- < 2.00 1995-08-21 1215 95-08-24 1015 32 < 1 20 < 5 40 3.6 < 2.00 1995-10-21 0250 95-10-22 0550 664 < 1 30 15 65 -- < 2.00 1995-10-22 0650 95-10-23 0950 564 < 1 30 7 50 -- < 2.00 1995-12-11 1140 95-12-14 1040 60 < 1 20 < 5 10 5.60 < 2.00 1996-01-16 1025 96-01-18 0925 178 < 1 40 5 30 6.10 < 2.00 1996-01-18 1005 96-01-20 0105 708 4 50 5 35 6.90 4.00 1996-01-20 0205 96-01-22 0905 848 4 40 9 40 6.90 2.40 1996-01-22 1055 96-01-25 0955 329 < 1 30 8 50 7.60 < 2.00 1996-01-25 1015 96-01-29 0915 288 < 1 40 6 25 6.00 < 2.00 1996-01-29 1025 96-02-01 0925 136 < 1 20 < 5 15 6.00 < 2.00 1996-02-01 1020 96-02-05 0920 94 < 1 30 < 5 20 5.20 2.40 1996-04-14 1035 96-04-17 0935 541 < 1 40 < 5 20 6.10 2.10 1996-04-18 1025 96-04-22 0925 222 < 1 30 < 5 20 -- -- 1996-10-20 1820 96-10-21 0920 -- < 1 50 18 50 -- 3.00 

Beginning of

sampling period

End of sampling

period Q 

(ft3/s)

Metals (micrograms per liter) Physical properties (m

Yr-mo-d Time Yr-mo-d Time Cd Cu Pb Zn TOC BOD 

5 

Appendix 1. Selected chemical analyses of water samples from Irondequoit Creek above Blossom Road and at Empire Boulevard (E

inflow and outflow sites), Monroe County, N.Y., 1990-96 (continued)
60 Effects of a Cattail Wetland on Water Quality of Irondequoit creek near Rochester, New York

Appendix 2. Monthly and annual constituent input and output loads and associated errors for Ellison Park wetland, Monroe County, N.Y

[Values are in tons. Input and output loads are based on data from Irondequoit Creek above Blossom Road and Irondequoit Creek at Empire Boulevarerror of prediction, which, when multiplied by 1.96 and added to and subtracted from the estimated load, provides 95-percent confidence limits of th

A. Nitrogen Compounds 

Month/

 year

Total nitrogen1

1Loads of total nitrogen are computed as the sum of ammonia-plus-organic and nitrate-plus-nitrite nitrogen loads. No associated errors of prediction are ava

Ammonia-plus-organic nitrogen Ammonia nitrogen Organic nitrogen2

2Loads of organic nitrogen are computed as the difference between ammonia-plus-organic and ammonia nitrogen loads. No associated errors of prediction a

Input

Load

Output

Load

Input Output Input Output Input

Load

Output

Load

Load Error Load Error Load Error Load Error 

10/90 19.24 20.01 10.82 0.99 10.91 0.76 0.18 0.04 0.18 0.03 10.63 10.72 11/90 20.05 20.82 10.40 0.87 10.57 0.69 0.19 0.04 0.23 0.04 10.21 10.34 12/90 49.19 44.53 25.05 2.82 20.06 1.63 0.62 0.19 0.58 0.12 24.43 19.48 

1/91 45.24 39.17 19.59 1.86 15.07 1.17 0.68 0.16 0.57 0.11 18.92 14.51 2/91 36.82 31.52 14.33 1.31 11.05 0.78 0.59 0.14 0.42 0.08 13.75 10.63 3/91 66.69 61.58 30.08 2.96 25.58 1.99 0.99 0.26 0.64 0.13 29.09 24.95 4/91 53.98 46.39 28.03 3.01 23.94 2.08 0.62 0.16 0.43 0.09 27.40 23.51 5/91 25.85 19.92 13.47 1.07 11.00 0.69 0.27 0.06 0.23 0.04 13.21 10.77 6/91 9.55 9.58 5.13 0.45 5.62 0.36 0.10 0.02 0.16 0.03 5.02 5.46 7/91 8.38 7.70 4.57 0.38 4.45 0.28 0.10 0.02 0.15 0.02 4.46 4.30 8/91 7.28 7.12 3.91 0.32 3.95 0.25 0.09 0.02 0.12 0.02 3.83 3.83 9/91 5.50 6.05 2.89 0.25 3.33 0.22 0.06 0.01 0.09 0.01 2.83 3.25 

WY91 total 347.78 314.38 168.27 16.27 145.54 10.92 4.49 1.14 3.80 0.72 163.78 141.74 

10/91 6.32 7.50 3.23 0.26 4.08 0.25 0.05 0.01 0.10 0.02 3.17 3.98 11/91 7.33 9.28 3.48 0.30 4.67 0.31 0.06 0.01 0.14 0.02 3.42 4.53 12/91 11.85 15.24 5.14 0.51 6.64 0.46 0.13 0.03 0.27 0.05 5.01 6.37 

1/92 13.98 17.25 5.07 0.42 6.25 0.40 0.18 0.04 0.34 0.06 4.89 5.91 2/92 16.44 18.80 5.70 0.51 6.49 0.44 0.22 0.05 0.31 0.05 5.47 6.17 3/92 40.42 46.78 17.94 2.15 20.26 1.80 0.49 0.14 0.56 0.11 17.45 19.69 4/92 43.90 42.59 21.30 1.90 20.95 1.42 0.45 0.10 0.48 0.08 20.86 20.47 5/92 26.34 24.82 13.86 1.43 13.76 1.03 0.24 0.06 0.33 0.06 13.62 13.43 6/92 14.93 14.19 8.07 0.66 8.21 0.53 0.14 0.03 0.26 0.04 7.93 7.95 7/92 33.71 28.91 20.58 2.34 16.85 1.43 0.35 0.10 0.52 0.11 20.23 16.33 8/92 44.06 39.35 27.61 3.11 22.66 1.95 0.45 0.13 0.60 0.12 27.16 22.06 9/92 18.03 17.57 10.06 0.87 9.49 0.63 0.16 0.04 0.25 0.04 9.90 9.24 

WY92 total 277.33 282.29 142.04 14.44 140.29 10.66 2.92 0.75 4.16 0.77 139.12 136.13 
Appendix 2 61

A. Nitrogen Compounds (continued)

Month/

water year

Total nitrogen Ammonia-plus-organic nitrogen Ammonia nitrogen Organic nitrogen 

Input

Load

Output

Load

Input Output Input Output Input

Load

Output

Load

Load Error Load Error Load Error Load Error Loa

10/92 15.29 16.50 8.13 0.67 8.79 0.56 0.11 0.02 0.22 0.04 8.01 8.57 7.11/92 30.35 31.38 16.10 1.47 15.94 1.10 0.23 0.06 0.46 0.08 15.87 15.48 14.212/92 38.69 37.92 18.26 1.78 16.46 1.17 0.37 0.10 0.71 0.13 17.89 15.75 20.4

1/93 53.94 52.63 22.63 1.93 19.72 1.31 0.62 0.14 1.04 0.18 22.00 18.68 31.32/93 20.46 22.01 6.90 0.55 7.32 0.46 0.24 0.05 0.43 0.07 6.66 6.89 13.53/93 62.43 58.18 29.05 3.49 25.15 2.16 0.67 0.19 0.80 0.16 28.38 24.34 33.34/93 79.64 74.61 40.93 4.29 37.33 3.02 0.76 0.22 0.94 0.19 40.16 36.38 38.75/93 19.96 14.09 9.71 0.76 7.51 0.46 0.16 0.03 0.24 0.04 9.55 7.27 10.26/93 16.98 14.51 9.03 0.76 8.23 0.53 0.14 0.03 0.31 0.05 8.90 7.92 7.97/93 8.79 8.98 4.56 0.36 4.97 0.30 0.08 0.02 0.23 0.04 4.48 4.74 4.28/93 7.20 7.09 3.66 0.28 3.78 0.23 0.07 0.01 0.17 0.03 3.59 3.61 3.59/93 10.38 9.59 5.38 0.46 5.03 0.33 0.08 0.02 0.18 0.03 5.30 4.85 5.0

WY93 total 364.12 347.49 174.32 16.80 160.21 11.62 3.54 0.89 5.72 1.03 170.79 154.48 189.8

10/93 8.33 8.17 4.08 0.32 4.24 0.26 0.05 0.01 0.14 0.02 4.03 4.09 4.211/93 17.05 17.52 8.49 1.09 8.54 0.70 0.11 0.04 0.32 0.07 8.37 8.21 8.512/93 16.60 17.21 6.93 0.61 7.23 0.49 0.13 0.03 0.40 0.07 6.81 6.83 9.6

1/94 14.81 14.28 5.05 0.53 4.82 0.36 0.15 0.04 0.38 0.07 4.90 4.44 9.72/94 28.08 30.53 10.28 1.36 10.58 1.04 0.30 0.10 0.63 0.14 9.98 9.95 17.83/94 53.38 52.02 21.97 2.20 20.43 1.47 0.49 0.12 0.85 0.15 21.47 19.58 31.44/94 44.97 42.93 20.33 1.95 19.71 1.39 0.35 0.09 0.66 0.12 19.98 19.05 24.65/94 21.51 22.36 10.17 0.81 11.63 0.72 0.14 0.03 0.42 0.07 10.02 11.21 11.36/94 12.93 12.51 6.51 0.58 6.86 0.46 0.09 0.02 0.31 0.05 6.42 6.55 6.47/94 6.64 6.79 3.24 0.25 3.65 0.22 0.05 0.01 0.21 0.03 3.19 3.43 3.48/94 11.54 10.61 5.88 0.55 5.43 0.38 0.09 0.02 0.27 0.05 5.79 5.16 5.69/94 8.51 8.55 4.14 0.35 4.31 0.28 0.06 0.01 0.18 0.03 4.09 4.12 4.3

WY94 total 244.33 243.49 107.07 10.60 107.42 7.76 2.01 0.52 4.78 0.87 105.05 102.64 137.2

Appendix 2. Monthly and annual constituent input and output loads and associated errors for Ellison Park wetland, Monroe County, N.Y., 19
62 Effects of a Cattail Wetland on Water Quality of Irondequoit creek near Rochester, New York 10/94 6.14 6.02 2.80 0.22 3.01 0.18 0.03 0.01 0.13 0.02 2.77 2.88 3.3

11/94 12.38 12.09 5.77 0.65 5.79 0.50 0.07 0.02 0.25 0.05 5.70 5.54 6.612/94 18.10 17.63 7.16 0.62 6.98 0.47 0.12 0.03 0.47 0.08 7.05 6.51 10.9

1/95 18.41 18.09 6.06 0.64 5.80 0.46 0.15 0.04 0.52 0.10 5.91 5.28 12.32/95 12.68 12.50 3.61 0.32 3.74 0.26 0.10 0.02 0.34 0.06 3.51 3.41 9.03/95 25.83 25.36 8.38 0.71 8.48 0.55 0.20 0.04 0.52 0.09 8.18 7.95 17.44/95 11.58 11.06 4.10 0.34 4.60 0.30 0.07 0.02 0.23 0.04 4.03 4.37 7.45/95 8.60 8.51 3.54 0.29 4.21 0.27 0.05 0.01 0.21 0.04 3.49 4.00 5.06/95 6.48 6.27 2.93 0.26 3.30 0.23 0.04 0.01 0.20 0.04 2.89 3.10 3.57/95 8.92 8.24 4.22 0.37 4.20 0.27 0.06 0.01 0.28 0.05 4.16 3.91 4.78/95 5.96 5.70 2.74 0.26 2.80 0.20 0.04 0.01 0.19 0.03 2.70 2.61 3.29/95 4.10 3.92 1.79 0.15 1.90 0.12 0.02 0.01 0.11 0.02 1.76 1.79 2.3

WY95 total 139.17 135.39 53.11 4.82 54.82 3.82 0.96 0.23 3.47 0.61 52.16 51.36 86.0

10/95 15.00 14.63 7.65 1.26 7.14 0.72 0.07 0.03 0.29 0.07 7.58 6.84 7.311/95 18.04 18.28 7.77 0.72 7.89 0.55 0.08 0.02 0.43 0.08 7.68 7.46 10.212/95 12.01 12.90 4.17 0.35 4.70 0.31 0.06 0.01 0.41 0.07 4.11 4.30 7.8

1/96 41.21 38.58 14.99 2.07 12.20 1.16 0.31 0.11 1.13 0.26 14.69 11.07 26.22/96 26.38 26.19 7.84 0.89 7.45 0.60 0.19 0.05 0.69 0.14 7.65 6.76 18.53/96 29.89 30.21 9.41 0.86 9.76 0.68 0.18 0.04 0.66 0.12 9.22 9.10 20.44/96 40.74 36.36 16.71 1.80 15.29 1.19 0.22 0.06 0.73 0.14 16.49 14.56 24.05/96 39.65 32.88 18.52 2.08 15.82 1.23 0.19 0.06 0.74 0.14 18.32 15.07 21.6/96 27.32 22.22 13.31 1.31 11.08 0.82 0.14 0.04 0.67 0.13 13.17 10.41 14.07/96 12.23 10.19 5.48 0.46 4.83 0.32 0.07 0.01 0.38 0.06 5.41 4.45 6.78/96 7.92 7.10 3.42 0.31 3.21 0.22 0.04 0.01 0.25 0.04 3.37 2.96 4.59/96 8.33 8.16 3.57 0.35 3.62 0.26 0.04 0.01 0.22 0.04 3.53 3.39 4.7

WY96 total 278.72 257.69 112.81 12.46 102.99 8.07 1.59 0.45 6.62 1.28 111.22 96.37 165.9

Period of 

record 

1990-96 1,651 1,581 757.64 75.39 711.27 52.84 15.52 3.98 28.55 5.29 742.12 682.73 893.8

A. Nitrogen Compounds (continued)

Month/

water year

Total nitrogen Ammonia-plus-organic nitrogen Ammonia nitrogen Organic nitrogen 

Input

Load

Output

Load

Input Output Input Output Input

Load

Output

Load

Load Error Load Error Load Error Load Error Loa

Appendix 2. Monthly and annual constituent input and output loads and associated errors for Ellison Park wetland, Monroe County, N.Y., 19
Appendix 2 63

Appendix 2. Monthly and annual constituent input and output loads and associated errors for Ellison Park wetland,

Monroe County, N.Y., 1990-96 (continued) 

[Values are in tons. Input and output loads are based on data from Irondequoit Creek above Blossom Road and Irondequoit Creek 

at Empire Boulevard, respectively. Error is standard error of prediction, which, when multiplied by 1.96 and added to and

subtracted from the estimated load, provides 95-percent confidence limits of the load estimate. WY, water year.]

B. Phosphorus Compounds 

Month/

year

Total phosphorus, as P Orthophosphate, as P

Input Output Input Output

Load Error Load Error Load Error Load Error

10/90 2.36 0.47 2.39 0.28 0.16 0.02 0.23 0.02

11/90 1.49 0.25 1.54 0.16 0.13 0.01 0.18 0.01

12/90 4.53 1.33 3.10 0.48 0.32 0.05 0.38 0.04

1/91 2.53 0.56 2.05 0.29 0.21 0.03 0.25 0.03

2/91 1.72 0.32 1.46 0.16 0.12 0.01 0.14 0.01

3/91 6.29 1.46 5.14 0.72 0.23 0.03 0.32 0.03

4/91 7.20 2.11 5.48 0.94 0.20 0.03 0.28 0.03

5/91 2.09 0.31 1.85 0.18 0.10 0.01 0.12 0.01

6/91 0.75 0.14 1.00 0.10 0.06 0.01 0.09 0.01

7/91 0.75 0.12 0.92 0.09 0.07 0.01 0.11 0.01

8/91 0.73 0.12 0.89 0.09 0.07 0.01 0.11 0.01

9/91 0.52 0.09 0.64 0.07 0.05 0.01 0.08 0.01

WY91 total 30.94 7.27 26.44 3.55 1.72 0.23 2.30 0.21

10/91 0.47 0.07 0.58 0.05 0.05 0.01 0.08 0.01

11/91 0.36 0.06 0.47 0.05 0.05 0.01 0.08 0.01

12/91 0.46 0.10 0.60 0.07 0.06 0.01 0.11 0.01

1/92 0.37 0.06 0.53 0.05 0.05 0.01 0.09 0.01

2/92 0.49 0.09 0.64 0.07 0.05 0.01 0.08 0.01

3/92 3.73 1.16 3.64 0.65 0.13 0.02 0.25 0.03

4/92 3.89 0.77 3.41 0.37 0.14 0.02 0.23 0.02

5/92 2.52 0.69 2.25 0.30 0.11 0.02 0.17 0.01

6/92 1.20 0.19 1.35 0.13 0.09 0.01 0.15 0.01

7/92 6.40 1.89 4.84 0.76 0.36 0.06 0.60 0.06

8/92 11.76 3.23 7.88 1.21 0.58 0.09 0.98 0.10

9/92 2.33 0.40 1.99 0.21 0.17 0.02 0.28 0.02

WY92 total 33.96 8.70 28.17 3.91 1.85 0.26 3.09 0.29

10/92 1.40 0.23 1.27 0.13 0.12 0.01 0.19 0.01

11/92 2.65 0.51 1.98 0.22 0.23 0.03 0.33 0.03

12/92 2.42 0.54 1.68 0.19 0.24 0.03 0.33 0.03

1/93 2.72 0.48 2.04 0.21 0.26 0.03 0.37 0.03

2/93 0.57 0.09 0.63 0.06 0.06 0.01 0.09 0.01

3/93 8.26 2.60 4.38 0.73 0.26 0.05 0.36 0.04

4/93 12.48 3.56 7.44 1.19 0.36 0.06 0.55 0.06

5/93 1.33 0.20 0.89 0.08 0.08 0.01 0.09 0.01

6/93 1.42 0.24 1.25 0.12 0.11 0.01 0.16 0.01

7/93 0.72 0.11 0.83 0.08 0.08 0.01 0.14 0.01

8/93 0.65 0.10 0.67 0.06 0.08 0.01 0.12 0.01

9/93 1.08 0.18 0.86 0.09 0.10 0.01 0.15 0.01

WY93 total 35.70 8.83 23.92 3.17 1.99 0.26 2.90 0.25
64 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

10/93 0.61 0.09 0.49 0.05 0.07 0.01 0.09 0.01

11/93 1.41 0.48 0.89 0.13 0.14 0.03 0.18 0.02

12/93 0.67 0.13 0.56 0.06 0.10 0.01 0.14 0.01

1/94 0.44 0.11 0.35 0.05 0.06 0.01 0.08 0.01

2/94 1.62 0.58 1.28 0.25 0.11 0.02 0.18 0.02

3/94 4.57 1.13 2.81 0.35 0.20 0.03 0.28 0.02

4/94 4.28 1.01 2.82 0.34 0.18 0.02 0.25 0.02

5/94 1.54 0.24 1.50 0.14 0.10 0.01 0.16 0.01

6/94 1.06 0.20 1.00 0.11 0.09 0.01 0.15 0.01

7/94 0.52 0.08 0.56 0.05 0.07 0.01 0.11 0.01

8/94 1.35 0.28 1.05 0.12 0.14 0.02 0.21 0.02

9/94 0.85 0.14 0.69 0.07 0.09 0.01 0.14 0.01

WY94 total 18.92 4.45 14.00 1.71 1.36 0.18 1.98 0.17

10/94 0.43 0.06 0.33 0.03 0.06 0.01 0.07 0.00

11/94 0.99 0.29 0.63 0.11 0.11 0.02 0.14 0.01

12/94 0.76 0.13 0.53 0.06 0.12 0.01 0.14 0.01

1/95 0.62 0.16 0.46 0.06 0.09 0.01 0.11 0.01

2/95 0.32 0.06 0.28 0.03 0.04 0.00 0.05 0.00

3/95 1.07 0.18 0.84 0.08 0.08 0.01 0.11 0.01

4/95 0.50 0.08 0.44 0.04 0.04 0.00 0.05 0.00

5/95 0.48 0.07 0.45 0.04 0.04 0.00 0.06 0.00

6/95 0.46 0.08 0.43 0.05 0.05 0.01 0.07 0.01

7/95 0.82 0.14 0.69 0.07 0.10 0.01 0.14 0.01

8/95 0.61 0.12 0.50 0.06 0.08 0.01 0.11 0.01

9/95 0.37 0.06 0.28 0.03 0.05 0.01 0.06 0.00

WY95 total 7.43 1.43 5.86 0.66 0.88 0.11 1.14 0.09

10/95 3.00 1.37 1.19 0.23 0.22 0.05 0.24 0.03

11/95 1.32 0.25 0.80 0.09 0.17 0.02 0.20 0.02

12/95 0.44 0.07 0.34 0.03 0.09 0.01 0.10 0.01

1/96 3.55 1.30 1.45 0.26 0.32 0.07 0.33 0.04

2/96 1.28 0.39 0.78 0.11 0.12 0.02 0.14 0.01

3/96 1.65 0.32 1.15 0.13 0.12 0.01 0.15 0.01

4/96 5.07 1.36 2.45 0.33 0.23 0.04 0.25 0.02

5/96 6.52 2.06 2.81 0.39 0.31 0.05 0.32 0.03

6/96 4.09 0.88 2.21 0.28 0.32 0.04 0.36 0.03

7/96 1.34 0.22 0.90 0.09 0.17 0.02 0.19 0.01

8/96 0.93 0.17 0.63 0.07 0.13 0.02 0.15 0.01

9/96 1.07 0.24 0.67 0.08 0.13 0.02 0.15 0.01

WY96 total 30.25 8.62 15.41 2.10 2.32 0.37 2.57 0.24

Period of record 

1990-96 157.19 39.30 113.81 15.11 10.12 1.42 13.97 1.25

B. Phosphorus Compounds (continued)

Month/

year

Total phosphorus, as P Orthophosphate, as P

Input Output Input Output

Load Error Load Error Load Error Load Error

Appendix 2. Monthly and annual constituent input and output loads and associated errors for Ellison Park wetland,

Monroe County, N.Y., 1990-96 (continued)
Appendix 2 65

Appendix 2. Monthly and annual constituent input and output loads and associated errors for Ellison Park wetland, 

Monroe County, N.Y., 1990-96 (continued)

[Values are in tons. Input and output loads are based on data from Irondequoit Creek above Blossom Road and Irondequoit Creek 

at Empire Boulevard, respectively. Error is standard error of prediction, which, when multiplied by 1.96 and added to and

subtracted from the estimated load, provides 95-percent confidence limits of the load estimate. WY, water year.] 

C. Selected Anions (chloride and sulfate) 

Month/year

Chloride Sulfate

Input Output Input Output

Load Error Load Error Load Error Load Error

10/90 874 36 893 38 1242 46 1179 40

11/90 1056 43 1067 44 1242 45 1174 39

12/90 2249 101 2206 101 1739 65 1627 56

1/91 2575 105 2416 103 1683 61 1512 50

2/91 2328 97 2199 95 1470 54 1324 45

3/91 3232 136 3215 144 2112 77 1991 68

4/91 2222 92 2065 91 1926 70 1743 59

5/91 1183 46 1006 41 1417 48 1205 38

6/91 488 20 511 21 813 29 800 26

7/91 436 17 435 18 785 27 741 24

8/91 412 16 426 17 774 27 744 24

9/91 357 15 382 16 702 25 691 23

WY91 total 17,414 725 16,821 729 15,903 575 14,731 490

10/91 441 17 483 19 792 27 799 25

11/91 557 23 642 27 797 28 838 27

12/91 914 39 1128 48 939 33 1046 33

1/92 1248 49 1520 61 1017 34 1113 34

2/92 1415 59 1663 71 1051 37 1127 36

3/92 2317 100 2766 121 1703 61 1877 62

4/92 2184 87 2257 93 1922 66 1908 60

5/92 1244 52 1252 54 1466 50 1433 45

6/92 741 29 757 31 1104 37 1083 34

7/92 1176 51 1201 55 1581 56 1546 50

8/92 1441 64 1521 71 1873 67 1875 63

9/92 906 36 940 39 1361 46 1335 42

WY92 total 14,584 608 16,130 690 15,606 543 15,981 510

10/92 904 35 961 38 1315 44 1321 40

11/92 1624 67 1699 72 1725 60 1732 55

12/92 2315 98 2413 103 1828 63 1832 58

1/93 3482 137 3672 149 2150 73 2168 67

2/93 1838 73 2068 84 1272 44 1329 42

3/93 3294 143 3496 151 2217 83 2263 77

4/93 3426 152 3528 165 2627 98 2638 92

5/93 1161 45 936 37 1413 47 1176 36

6/93 875 34 839 34 1241 42 1171 37

7/93 537 20 593 23 920 31 948 29

8/93 485 18 513 20 876 30 868 27

9/93 663 26 649 27 1087 37 1021 32

WY93 total 20,605 849 21,366 903 18,670 651 18,467 592
66 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

10/93 633 24 615 24 1023 34 960 29

11/93 1108 51 1165 54 1271 46 1283 42

12/93 1377 54 1445 58 1285 43 1285 40

1/94 1443 62 1499 66 1101 38 1086 34

2/94 2197 104 2510 123 1398 54 1484 53

3/94 3376 138 3652 150 2227 79 2298 74

4/94 2558 105 2674 112 2100 74 2120 68

5/94 1298 50 1412 56 1516 51 1569 48

6/94 762 30 804 33 1108 38 1114 35

7/94 467 18 517 20 823 28 848 26

8/94 710 29 734 31 1116 38 1089 34

9/94 616 24 643 26 1016 35 995 31

WY94 total 16,545 690 17,670 753 15,983 559 16,131 516

10/94 540 21 524 21 902 30 842 26

11/94 941 40 910 41 1149 41 1073 36

12/94 1555 62 1573 64 1371 46 1325 41

1/95 1769 77 1860 84 1241 43 1225 39

2/95 1412 59 1500 64 1020 36 1009 32

3/95 2282 91 2422 100 1611 54 1602 50

4/95 1061 43 1076 44 1098 37 1060 33

5/95 704 28 727 30 960 32 942 29

6/95 486 20 503 22 786 28 769 25

7/95 605 24 632 26 955 32 935 29

8/95 457 19 479 21 794 28 768 25

9/95 380 15 374 16 709 25 655 22

WY95 total 12,193 498 12,580 532 12,595 434 12,204 386

10/95 913 47 962 49 1205 47 1191 41

11/95 1370 58 1410 61 1426 50 1385 45

12/95 1219 48 1327 54 1119 38 1121 35

1/96 3014 150 3186 160 1718 67 1698 61

2/96 2419 108 2630 119 1448 54 1445 49

3/96 2540 104 2780 116 1706 61 1714 56

4/96 2495 108 2515 110 1975 74 1889 65

5/96 2061 89 1994 87 1977 73 1836 62

6/96 1394 60 1348 60 1600 60 1473 51

7/96 809 32 785 32 1132 41 1028 34

8/96 601 24 610 25 930 34 867 29

9/96 655 28 678 30 984 37 926 32

WY96 total 19,491 857 20,226 904 17,220 638 16,574 561

Period of record 

1990-96 100,832 4,226 104,793 4,512 95,978 3,400 94,087 3,055

C. Selected Anions (chloride and sulfate) (continued) 

Month/year

Chloride Sulfate

Input Output Input Output

Load Error Load Error Load Error Load Error

Appendix 2. Monthly and annual constituent input and output loads and associated errors for Ellison Park 

wetland, Monroe County, N.Y., 1990-96 (continued)
Appendix 2 67

Appendix 2. Monthly and annual constituent input and output loads and associated errors for Ellison Park wetland,

Monroe County, N.Y., 1990-96 (continued) 

[Values are in tons. Input and output loads are based on data from Irondequoit Creek above Blossom Road and Irondequoit Creek 

at Empire Boulevard, respectively. Error is standard error of prediction, which, when multiplied by 1.96 and added to and

subtracted from the estimated load, provides 95-percent confidence limits of the load estimate. WY, water year.]

D. Suspended Solids Nonvolatile 

suspended solids1

Month/

year

Total suspended solids Volatile suspended solids

Input Output Input Output Input

Load

Output

Load Error Load Error Load Error Load Error Load

10/90 2541 719 2038 411 357 85 303 46 2184 1736

11/90 1815 453 1470 270 278 60 247 35 1537 1222

12/90 5072 1755 3229 791 628 171 453 76 4444 2776

1/91 3390 957 2267 512 454 105 336 53 2936 1931

2/91 2529 651 1660 310 343 75 248 35 2186 1412

3/91 7640 2151 5317 1151 848 196 590 91 6792 4726

4/91 7778 2547 4882 1219 816 207 494 82 6962 4388

5/91 2631 553 1520 234 341 62 199 23 2291 1321

6/91 775 200 672 107 117 25 100 12 657 572

7/91 693 157 550 87 110 21 88 11 583 462

8/91 633 144 508 81 105 20 88 11 528 420

9/91 446 109 374 65 80 17 74 10 365 300

WY91 total 35,944 10,396 24,486 5,239 4,479 1,044 3,221 483 31,465 21,265

10/91 439 97 374 61 83 16 81 10 356 293

11/91 382 93 349 63 74 15 79 11 308 270

12/91 565 166 516 103 99 24 108 16 466 408

1/92 502 122 484 88 92 19 102 14 411 382

2/92 712 179 601 110 116 25 111 16 596 490

3/92 4088 1480 3035 773 467 131 361 61 3621 2674

4/92 4637 1139 2769 478 550 111 341 43 4088 2428

5/92 2767 888 1617 334 339 82 207 29 2428 1410

6/92 1265 272 831 131 181 33 122 15 1084 708

7/92 5190 1774 2681 638 580 152 310 49 4610 2371

8/92 8481 2782 4195 994 912 239 478 79 7569 3718

9/92 2146 494 1144 195 308 60 188 24 1838 957

WY92 total 31,175 9,487 18,595 3,967 3,800 908 2,486 367 27,374 16,109

10/92 1395 317 801 136 222 43 153 20 1173 648

11/92 2770 700 1421 265 397 84 251 35 2373 1170

12/92 2741 767 1358 267 387 88 242 35 2354 1116

1/93 3389 789 1769 317 470 94 298 41 2918 1471

2/93 825 185 558 97 136 27 109 15 688 449

3/93 7624 2728 3369 813 795 225 398 66 6829 2971

4/93 11292 3500 5366 1228 1148 284 574 92 10143 4792

5/93 1593 329 598 95 223 40 96 12 1370 503

6/93 1501 343 737 122 209 40 111 14 1292 627

7/93 657 138 433 70 106 19 75 9 550 359

8/93 558 115 332 54 96 17 64 8 463 268

9/93 998 233 466 82 159 31 89 12 839 378

WY93 total 35,343 10,144 17,209 3,547 4,350 991 2,458 359 30,993 14,751

1 Loads of nonvolatile suspended solids are computed as the difference between total suspended solids and 

volatile suspended solids. No associated errors of prediction are available.
68 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

10/93 600 130 290 50 108 20 66 9 492 224

11/93 1422 579 634 148 208 63 122 20 1214 512

12/93 835 217 442 86 142 31 96 14 693 346

1/94 591 199 303 69 99 26 65 11 492 237

2/94 1931 805 1102 315 247 79 162 31 1684 940

3/94 5271 1542 2378 457 607 143 311 43 4664 2067

4/94 4969 1389 2247 423 571 128 281 38 4398 1966

5/94 1905 407 1078 170 257 47 151 18 1649 927

6/94 1139 286 617 112 161 33 92 12 977 525

7/94 475 98 299 48 80 14 54 7 395 246

8/94 1275 345 592 112 185 40 97 13 1090 496

9/94 822 191 405 72 134 26 77 10 688 328

WY94 total 21,236 6,188 10,388 2,062 2,800 651 1,574 227 18,436 8,814

10/94 428 91 203 34 80 15 48 6 348 155

11/94 1072 391 464 122 163 45 88 15 909 376

12/94 1021 246 470 85 167 35 97 14 854 373

1/95 895 293 446 104 139 36 85 14 756 361

2/95 504 138 280 56 85 19 56 8 419 224

3/95 1658 386 842 145 234 47 132 17 1425 710

4/95 729 167 389 68 112 22 65 9 617 325

5/95 605 138 347 62 94 19 56 8 510 291

6/95 506 128 290 58 79 17 47 7 427 243

7/95 873 213 451 85 129 26 70 10 743 381

8/95 596 167 314 68 94 21 53 8 502 261

9/95 348 81 177 34 63 13 37 6 285 140

WY95 total 9,235 2,438 4,674 920 1,440 314 833 122 7,795 3,841

10/95 2738 1455 953 291 323 128 140 28 2415 813

11/95 1741 452 768 153 256 56 135 20 1485 633

12/95 655 161 363 70 113 24 74 11 542 288

1/96 4330 1809 1697 472 489 160 225 43 3841 1472

2/96 2016 733 978 240 258 73 139 24 1757 838

3/96 2755 733 1422 302 343 77 183 30 2412 1239

4/96 6767 2215 2728 674 692 183 280 51 6076 2447

5/96 7824 2839 2863 742 770 218 282 54 7053 2581

6/96 5110 1514 2044 526 547 137 211 42 4563 1833

7/96 1663 425 769 187 221 49 100 19 1443 669

8/96 1072 302 523 132 153 37 76 15 919 447

9/96 1284 421 615 168 181 49 92 19 1102 523

WY96 total 37,955 13,059 15,721 3,959 4,347 1,190 1,936 358 33,608 13,785

Period of 

record 

1990-96 170,888 51,712 91,074 19,693 21,215 5,097 12,508 1,915 149,673 78,565

1

D. Suspended Solids (continued) Nonvolatile 

suspended solids1

Month/

year

Total suspended solids Volatile suspended solids

Input Output Input Output Input

Load

Output

Load Error Load Error Load Error Load Error Load

Appendix 2. Monthly and annual constituent input and output loads and associated errors for Ellison Park wetland, 

Monroe County, N.Y., 1990-96 (continued)
Appendix 3 69

Month/

year

Percent removal

Total 

nitrogen

Ammonia 

plus organic

nitrogen

Ammonia 

nitrogen

Organic 

nitrogen

Nitrate plus 

nitrite

Total 

 phosphorus

Orthophosphate Chloride Sulfate

T

susp

so

10/90 -4.0 -0.9 -1.1 -0.8 -8.0 -1.0 -45.0 -2.3 5.1 11/90 -3.9 -1.6 -17.6 -1.3 -6.3 -3.8 -36.5 -1.0 5.4 12/90 9.5 19.9 6.9 20.3 -1.4 31.7 -19.2 1.9 6.4 

1/91 13.4 23.1 16.0 23.3 6.0 19.0 -20.7 6.2 10.2 2/91 14.4 22.9 28.8 22.6 9.0 15.2 -17.5 5.6 9.9 3/91 7.7 15.0 35.8 14.2 1.7 18.3 -41.3 0.5 5.7 4/91 14.1 14.6 30.1 14.2 13.5 23.8 -39.1 7.1 9.5 5/91 22.9 18.3 11.6 18.5 27.9 11.6 -22.6 15.0 15.0 6/91 -0.3 -9.7 -50.9 -8.8 10.5 -33.7 -62.5 -4.6 1.5 7/91 8.1 2.6 -46.3 3.7 14.7 -23.1 -53.7 0.2 5.5 8/91 2.3 -1.1 -43.2 -0.1 6.2 -22.0 -58.4 -3.4 3.9 9/91 -9.9 -15.5 -56.0 -14.7 -3.6 -23.3 -59.0 -6.9 1.6 

WY91 9.6 13.5 15.3 13.4 5.9 14.5 -34.1 3.4 7.4 

10/91 -18.7 -26.4 -79.9 -25.5 -10.6 -23.9 -57.7 -9.5 -0.9 11/91 -26.5 -34.2 -117 -32.6 -19.6 -31.4 -61.7 -15.3 -5.2 12/91 -28.6 -29.2 -114 -27.1 -28.0 -31.2 -71.8 -23.4 -11.4 

1/92 -23.4 -23.1 -85.2 -20.8 -23.5 -42.9 -70.9 -21.8 -9.5 2/92 -14.4 -13.9 -39.1 -12.9 -14.7 -29.3 -66.9 -17.5 -7.1 3/92 -15.7 -12.9 -14.3 -12.8 -18.0 2.5 -90.5 -19.4 -10.2 4/92 3.0 1.7 -8.1 1.9 4.2 12.2 -57.0 -3.3 0.7 5/92 5.8 0.7 -36.5 1.4 11.3 10.5 -56.4 -0.7 2.3 6/92 4.9 -1.7 -81.4 -0.3 12.7 -12.3 -64.9 -2.2 1.9 7/92 14.2 18.1 -48.0 19.3 8.1 24.4 -66.3 -2.2 2.2 8/92 10.7 17.9 -35.4 18.8 -1.5 33.0 -70.1 -5.6 -0.1 9/92 2.6 5.7 -59.4 6.7 -1.3 14.5 -58.6 -3.7 1.9 

WY92 -1.8 1.2 -42.2 2.2 -5.0 17.1 -67.1 -10.6 -2.4 

Appendix 3. Monthly removal efficiencies for selected constituents as percentage of input load retained in Ellison Park wetland, Monro[Values are in percent. Positive and negative values indicate net constituent retention in or export from wetland, respectively. WY, water year. Water are based on total annual loads and are not mean monthly values.]
70 Effects of a CAttail Wetland on Water Quality of the Irondequoit Creek near Rochester, New York 10/92 -8.0 -8.2 -97.4 -6.9 -7.7 8.9 -56.4 -6.2 -0.4 42.6 

11/92 -3.4 1.0 -98.5 2.4 -8.3 25.3 -46.3 -4.7 -0.4 48.7 12/92 2.0 9.9 -90.4 11.9 -5.1 30.6 -36.0 -4.2 -0.2 50.4 

1/93 2.4 12.9 -66.2 15.1 -5.1 25.0 -41.7 -5.4 -0.8 47.8 2/93 -7.6 -6.0 -76.7 -3.5 -8.3 -10.3 -56.9 -12.5 -4.5 32.4 3/93 6.8 13.4 -19.3 14.2 1.1 47.0 -37.4 -6.1 -2.1 55.8 4/93 6.3 8.8 -23.6 9.4 3.7 40.4 -52.4 -3.0 -0.4 52.5 5/93 29.4 22.6 -54.1 23.9 35.8 32.5 -10.9 19.4 16.8 62.4 6/93 14.5 8.9 -120 11.0 20.9 12.3 -48.5 4.2 5.6 50.9 7/93 -2.2 -9.0 -187 -5.8 5.2 -15.4 -75.2 -10.5 -3.1 34.0 8/93 1.6 -3.3 -163 -0.4 6.7 -2.3 -59.8 -5.7 0.9 40.5 9/93 7.6 6.5 -122 8.4 8.8 20.8 -41.8 2.1 6.1 53.3 

WY93 4.6 8.1 -61.8 9.5 1.3 33.0 -45.5 -3.7 1.1 51.3 

10/93 2.0 -3.8 -167 -1.6 7.5 19.5 -31.8 3.0 6.2 51.6 11/93 -2.8 -0.6 -181 1.9 -4.9 36.6 -32.8 -5.2 -0.9 55.4 12/93 -3.7 -4.3 -214 -0.4 -3.3 16.5 -37.9 -4.9 -0.0 47.0 

1/94 3.5 4.5 -160 9.4 3.1 19.6 -27.8 -3.9 1.3 48.8 2/94 -8.7 -2.9 -112 0.3 -12.1 21.1 -63.3 -14.3 -6.1 43.0 3/94 2.5 7.0 -72.0 8.8 -0.6 38.5 -40.7 -8.2 -3.2 54.9 4/94 4.5 3.1 -88.2 4.6 5.8 34.1 -44.0 -4.5 -1.0 54.8 5/94 -4.0 -14.4 -187 -11.9 5.4 2.4 -66.5 -8.8 -3.5 43.4 6/94 3.2 -5.4 -241 -2.0 12.0 5.5 -59.3 -5.5 -0.5 45.8 7/94 -2.2 -12.5 -306 -7.6 7.5 -7.4 -61.9 -10.8 -3.0 37.0 8/94 8.0 7.7 -206 10.9 8.4 22.4 -47.2 -3.5 2.4 53.5 9/94 -0.5 -3.9 -231 -0.8 2.7 19.1 -43.3 -4.3 2.0 50.8 

WY94 0.3 0.0 -137 2.3 0.1 26.0 -46.0 -6.8 -0.9 51.1 

Month/

year

Percent removal

Total 

nitrogen

Ammonia 

plus organic

nitrogen

Ammonia 

nitrogen

Organic 

nitrogen

Nitrate plus 

nitrite

Total 

 phosphorus

Orthophosphate Chloride Sulfate

Total 

suspende

solids

Appendix 3. Monthly removal efficiencies for selected constituents as percentage of input load retained in Ellison Park wetland, Monroe Co(continued)
Appendix 2 71

10/94 1.9 -7.6 -280 -4.3 9.8 23.7 -22.0 3.0 6.6 52.6 11/94 2.4 -0.3 -275 2.9 4.7 36.2 -25.1 3.3 6.7 56.7 12/94 2.6 2.6 -297 7.6 2.6 30.0 -20.5 -1.1 3.4 53.9 

1/95 1.7 4.3 -244 10.7 0.5 26.6 -25.2 -5.2 1.3 50.1 2/95 1.4 -3.7 -220 2.8 3.3 12.8 -26.7 -6.2 1.1 44.4 3/95 1.8 -1.1 -165 2.9 3.2 21.4 -33.3 -6.1 0.6 49.2 4/95 4.5 -12.3 -226 -8.5 13.7 12.1 -30.2 -1.4 3.5 46.6 5/95 1.1 -18.9 -334 -14.5 15.1 5.1 -37.3 -3.3 1.9 42.6 6/95 3.3 -12.6 -411 -7.2 16.5 6.6 -38.0 -3.6 2.2 42.7 7/95 7.6 0.5 -379 5.9 14.0 16.1 -38.4 -4.5 2.1 48.4 8/95 4.3 -2.1 -375 3.3 9.7 17.8 -35.3 -4.7 3.3 47.3 9/95 4.5 -6.4 -385 -1.5 13.0 23.9 -17.9 1.7 7.5 49.3 

WY95 2.7 -3.2 -262 1.5 6.4 21.1 -28.8 -3.2 3.1 49.4 

10/95 2.5 6.7 -320 9.7 -1.9 60.3 -8.7 -5.3 1.2 65.2 11/95 -1.3 -1.6 -415 2.9 -1.1 39.2 -14.9 -2.9 2.9 55.9 12/95 -7.4 -12.7 -527 -4.6 -4.6 22.3 -18.4 -8.8 -0.2 44.6 

1/96 6.4 18.6 -270 24.6 -0.6 59.1 -2.4 -5.7 1.1 60.8 2/96 0.7 4.9 -271 11.6 -1.0 38.9 -15.8 -8.7 0.2 51.5 3/96 -1.1 -3.7 -259 1.4 0.2 30.1 -24.7 -9.4 -0.5 48.4 4/96 10.8 8.5 -236 11.7 12.3 51.6 -9.7 -0.8 4.4 59.7 5/96 17.1 14.6 -284 17.7 19.2 56.9 -3.2 3.3 7.1 63.4 6/96 18.7 16.7 -379 21.0 20.5 45.8 -12.5 3.3 7.9 60.0 7/96 16.7 11.8 -465 17.8 20.7 32.6 -13.5 2.9 9.1 53.7 8/96 10.4 5.9 -484 12.2 13.8 31.5 -13.7 -1.5 6.8 51.2 9/96 2.0 -1.4 -486 3.8 4.6 36.9 -12.1 -3.4 5.9 52.1 

WY96 7.6 8.7 -315 13.4 6.8 49.0 -10.5 -3.8 3.8 58.6 

Period of record 

1990-96 4.3 6.1 -84.0 8.0 2.7 27.6 -38.1 -3.9 2.0 46.7 

Month/

year

Percent removal

Total 

nitrogen

Ammonia 

plus organic

nitrogen

Ammonia 

nitrogen

Organic 

nitrogen

Nitrate plus 

nitrite

Total 

 phosphorus

Orthophosphate Chloride Sulfate

Total 

suspende

solids

Appendix 3. Monthly removal efficiencies for selected constituents as percentage of input load retained in Ellison Park wetland, Monroe Co

(continued)
72 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

Appendix 4. Chemical analyses of four sediment samples collected in Ellison Park wetland,Monroe County, N.Y., 

October 1994.

[μg/g, microgram per gram; <63U or <180U WS, material passing through a 63- or 180-micrometer wet sieve, respectively;

 DW REC, dry weight recoverable; < , less than. SQ1 = Station 430951077312801. SQ2 = Station 430952077314001. 

SQ3 = Station 431021077315901. Locations are shown in fig. 2.] 

A. Major Elements, Trace Elements, and Carbon

 ALUM- ANTI- BERYLLOCAL INUM MONY ARSENIC BARIUM LIUM BISMUTH CADMIUM CALCIUM

SITE <63U WS <63U WS <63U WS <63U WS <63U WS <180U WS <63U WS <63U WS

ID (PERCENT) (μg/g) (μg/g) (μg/g) (μg/g) (μg/g) (μg/g) (PERCENT)

 

 SQ1 5.0 0.4 4.9 460 1 <10 0.9 6.4

 5.0 .5 5.1 460 1 <10 .7 6.6

 SQ2 4.9 .2 5.0 450 1 <10 .9 6.7

 SQ3 4.8 .6 3.9 470 1 <10 3.8 4.7

 CHRO- EURO- LANTHALOCAL CERIUM MIUM COBALT COPPER PIUM GALLIUM GOLD HOLMIUM IRON NUM

SITE <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS

 ID (μg/g) (μg/g) (μg/g) (μg/g) (μg/g) (μg/g) (μg/g) (μg/g) (PERCENT) (μg/g)

 SQ1 45 43 11 41 <2 11 <8 <4 2.7 25

 44 43 10 38 <2 12 <8 <4 2.7 25

 SQ2 45 46 12 49 <2 12 <8 <4 2.8 25

 SQ3 39 59 10 72 <2 11 <8 <4 2.4 23

 MAGNE- MANGA- MOLYB- NEODYM- PHOSLOCAL LEAD LITHIUM SIUM NESE MERCURY DENUM IUM NICKEL NIOBIUM PHORUS

SITE <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS

 ID (μg/g) (μg/g) (PERCENT) (μg/g) (μg/g) (μg/g) (μg/g) (μg/g) (μg/g) (PERCENT)

 SQ1 44 30 1.4 880 0.11 <2 25 19 12 0.13

 46 30 1.4 890 .10 <2 26 18 12 .13

 SQ2 62 30 1.2 720 .14 <2 24 20 11 .15

 SQ3 89 20 1.3 530 .33 <2 23 20 11 .12

 POTAS- SCAN- SELE- STRON- TANTALOCAL SIUM DIUM NIUM SILVER SODIUM TIUM SULFUR LUM THORIUM TIN

SITE <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS <63U WS

 ID (PERCENT) (μg/g) (μg/g) (μg/g) (PERCENT) (μg/g) (PERCENT) (μg/g) (μg/g) (μg/g)

 SQ1 1.7 8 0.5 0.5 1.2 420 0.34 <40 4.7 <10

 1.7 8 .6 .5 1.2 420 .33 <40 7.8 <10

 SQ2 1.6 8 .8 .7 1.1 440 .60 <40 6.5 <10

 SQ3 1.6 7 .8 2.3 1.3 340 .35 <40 5.7 <10

 CARBON, 

 TITA- CARBON, ORG + CARBON,

LOCAL NIUM, VANA- YTTER- ORGANIC INORG, INORGANIC,

SITE <63U WS URANIUM DIUM YTTRIUM BIUM ZINC <63U WS <63U WS <63U WS

 ID DW REC <63U WS <63U WS <63U WS <63U WS <63U WS DW REC DW REC DW REC 

 (PERCENT) (μg/g) (μg/g) (μg/g) (μg/g) (μg/g) (PERCENT) (PERCENT) (PERCENT)

 SQ1 0.26 1.6 50 20 2 210 3.4 5.4 1.9

 0.26 1.6 49 20 2 220 3.5 5.4 1.9

 SQ2 0.25 1.6 50 19 2 230 5.0 6.9 1.9

 SQ3 0.27 1.7 45 19 2 250 3.7 5.1 1.4
Appendix 4 73

B. Polycyclic aromatic hydrocarbons

 PARA- 4,6- 2,4-

 CHLORO- 2- 2,4-DI- DINITRO DI- 2- 4- PENTA- PHENOL

LOCAL META CHLORO- CHLORO- -ORTHO- NITRO- NITRO- NITRO- CHLORO- (C6H5

SITE CRESOL PHENOL PHENOL 2,4-DP CRESOL PHENOL PHENOL PHENOL PHENOL -OH)

 ID (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg)

 SQ1 <600 <200 <200 <200 <600 <600 <200 <600 <600 <200

 <600 <200 <200 <200 <600 <600 <200 <600 <600 <200

 SQ2 <600 <200 <200 <200 <600 <600 <200 <600 <600 <200

 SQ3 <600 <200 <200 <200 <600 <600 <200 <600 <600 <200

 BIS

 2,4,6- BENZO B BENZO K BENZO N-BUTYL (2-

 TRI- ACE- ACE- BENZO A FLUOR- FLUOR- BENZO- (G,H,I) BENZYL CHLOROLOCAL CHLORO- NAPHTH- NAPHTH- ANTHRA- ANTHRA- AN- AN- A- PERY- PHTHAL- ETHOXY)

SITE PHENOL ENE YLENE CENE CENE THENE THENE PYRENE LENE ATE METHANE

 ID (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg)

 SQ1 <600 <200 <200 <200 500 1,100 1,100 640 <400 <200 <200

 <600 <200 <200 <200 500 780 830 590 <400 <200 <200 

 SQ2 <600 <200 <200 <200 <400 750 740 500 <400 <200 <200

 SQ3 <600 <200 <200 <200 1,200 1,300 1,400 1,300 780 <200 <200

 BIS BIS (2- 4- 4-

 (2- CHLORO- BROMO- 2- CHLORO- 1,2,5,6 DI-N-

 CHLORO- ISO- PHENYL CHLORO- PHENYL -DIBENZ BUTYL 1,2-DI- 1,3-DI- 1,4-DILOCAL ETHYL) PROPYL) PHENYL NAPH- PHENYL CHRY- -ANTHRA PHTHAL- CHLORO- CHLORO- CHLOROSITE ETHER ETHER ETHER THALENE ETHER SENE -CENE ATE BENZENE BENZENE BENZENE

 ID (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg)

 SQ1 <200 <200 <200 <200 <200 900 <400 <200 <200 <200 <200

 <200 <200 <200 <200 <200 930 <400 <200 <200 <200 <200

 SQ2 <200 <200 <200 <200 <200 670 <400 <200 <200 <200 <200

 SQ3 <200 <200 <200 <200 <200 1,700 440 <200 <200 <200 <200

 BIS(2- HEXA-

 DI- DI-N- ETHYL HEXA- HEXA- CHLORO-

 DIETHYL METHYL 2,4-DI- 2,6-DI- OCTYL HEXYL) CHLORO- CHLORO- CYCLOLOCAL PHTHAL- PHTHAL- NITRO- NITRO- PHTHAL- PHTHAL- FLUOR- FLUOR- BENZENE BUT- PENTSITE ATE ATE TOLUENE TOLUENE ATE ATE ENE ANTHENE TOTAL ADIENCE ADIENE

 ID (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg)

 SQ1 <200 <200 <200 <200 <400 750 <200 1,700 <200 <200 <200

 <200 <200 <200 <200 <400 330 <200 2,000 <200 <200 <200

 SQ2 <200 <200 <200 <200 <400 510 <200 1,100 <200 <200 <200

 SQ3 <200 <200 <200 <200 <400 750 <200 3,300 <200 <200 <200

 INDENO N-NITRO N-NITRO N-NITRO- 1,2,4-

 HEXA- (1,2,3- -SODI- -SODI- SODI-N- TRILOCAL CHLORO- CD) ISO- NAPHTH- NITRO- METHY- PHENY- PROPYL- PHENAN- CHLOROSITE ETHANE PYRENE PHORONE ALENE BENZENE LAMINE LAMINE AMINE THRENE PYRENE BENZENE

 ID (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg)

 SQ1 <200 <400 <200 <200 <200 <200 <200 <200 580 1,300 <200

 <200 <400 <200 <200 <200 <200 <200 <200 880 1,500 <200

 SQ2 <200 <400 <200 <200 <200 <200 <200 <200 320 850 <200

 SQ3 <200 720 <200 <200 <200 <200 <200 <200 1,700 2,900 <200

Appendix 4. Analyses of sediment samples collected in the Ellison Park wetland, Monroe County, N.Y., 

October 1994 (continued)
74 Effects of a Cattail Wetland on Water Quality of Irondequoit Creek near Rochester, New York

 C. Organochlorine compounds

 CHLOR- P,P'- P,P'- P,P'- DI- ENDOLOCAL ALDRIN, DANE, DDD, DDE, DDT, ELDRIN, SULFAN, ENDRIN,

SITE TOTAL TOTAL RECOVER RECOVER RECOVER TOTAL TOTAL TOTAL

ID (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg)

SQ1 <0.1 22 3.8 7.1 1.0 2.3 <0.1 <0.8

 <0.1 19 3.1 6.2 .9 1.8 <0.1 <0.8

SQ2 <0.2 18 4.5 8.4 .6 1.2 <0.2 <1.6

SQ3 <0.1 26 6.5 7.4 .8 3.5 <0.1 <0.8

 HEPTA- METH- 

 CHLOR HEPTA- OXY- PER- TOXALOCAL EPOXIDE, CHLOR, LINDANE, CHLOR, MIREX, THANE, PHENE, PCB, PCN,

SITE TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL TOTAL

 ID (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg) (μg/kg)

 SQ1 <0.8 <0.1 <0.1 <32 <0.1 <1 <10 28 <1.0

 <0.8 <0.1 <0.1 <26 <0.1 <1 <10 25 <1.0

 SQ2 <1.6 <0.2 <0.2 <24 <0.2 <2 <20 43 <2.0

 SQ3 <0.8 <0.1 <0.1 <38 <0.1 <1 <10 52 <1.0

Appendix 4. Analyses of sediment samples collected in the Ellison Park wetland, Monroe County, N.Y., 

October 1994 (continued).