cazenovia lake: monitoring groundwater phosphorus · daniel kopec suny oneonta biological field...

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Cazenovia Lake: Monitoring Groundwater PhosphorusDaniel Kopec

SUNY Oneonta Biological Field Station, Cooperstown, NY

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Introduction Cazenovia Lake is a 1,184 acre lake located in

Madison County, NY (20 miles east of Syracuse, NY)

Nutrient enrichment has caused the lake to be

placed on the NYS Priority Waterbodies List as

“threatened” due to excessive aquatic macrophyte

growth and algae. These are symptoms of

eutrophication, suspected to be anthropogenic

The primary goal of this study is to provide the

Town of Cazenovia with an updated comprehensive

lake management plan, with the main focus of

monitoring groundwater nutrient influx and updating

the phosphorus budget for Cazenovia Lake based on

findings. The old 1992 budget is presented in Figure 2Figure 3. Image of an installed

piezometer while another is being

installed adjacent.

Piezometers

What are they?

A metal tube, with a pointed tip at the end

that has holes pre-drilled for entry of

groundwater, and is driven into the sub-surface

What do they do?

They allow the installer to successfully

retrieve groundwater samples from a desired

depth

Why do you need groundwater samples?

To accurately measure nutrient levels going

into a waterbody that may be associated with

residential septic systemsFigure 1. Installation of a piezometer on a

residential property.

Figure 4. Total phosphorus isopleths for the

year of 2014.Figure 6. Dissolved oxygen isopleths for

the year of 2014.

Lake Nutrients

Phosphorus is of greatest concern due to

Cazenovia Lake being phosphorus limited

Water samples were taken at 4 meter

intervals down to 12 meters. 2014 profile

data are plotted in Figure 4

Watershed Nutrients

Main concern with residential septic

systems and obtaining empirical data

Figure 7 displays that the majority of

residential land associated with lake

shoreline

Piezometers were installed at the edges of

5 residential properties with septic systems

to monitor phosphorus concentrations in

groundwater

Calculation of a nutrient budget using the Lake

Loading Response Model (LLRM)

Conducting a spring electrofishing survey to

obtain newer data on the fish community

Rhodamine dye testing to confirm the assumed

relationship between elevated groundwater

phosphorus and septic systems

Continued monitoring of the lake and

piezometers to obtain further data

Nutrient Monitoring

Figure 7.

Land use

attributes of

the

Cazenovia

Lake

watershed.

Figure 8.

Sub-

watershed

boundaries

of the

Cazenovia

Lake

watershed.

Current Work

Figure 5. Preliminary data indicate extreme

variation between sites and dates, with occasional

concentrations in the range of raw wastewater

effluent.

Figure 2.

Phosphorus

budget developed

in 1992 by Coastal

Environmental

Services

8/20/2014 8/30/2014 9/23/2014 10/7/2014 10/18/2014

Pro

pe

rty

1

1920 226 62 113 635

10450 682 39 146 610

4675 410 39 142 143

1160 504 38 467 202

4205 564 42 393 645P

rop

ert

y 2

227 147 20 72 143

171 416 34 49 24

107 17 47 35 32

227 44 89 34 36

4500 812 33 189 700

Pro

pe

rty

3

121 25 26 109 26

91 130 68 25 24

544 488 16 63 37

194 56 47 90 45

126 112 71 80 NA

114 92 161 84 70

3490 102 135 335 80

487 510 86 40 51