top of page


Water Quality Monitoring Program


The Canandaigua Lake Watershed Council has partnered with Finger Lakes Community College for the past 20+ years to monitor the lake for nutrients, chlorophyll, temperature, and dissolved oxygen.

Click HERE for the 2018 Monitoring Program Presentation.

Phosphorus & Nutrients

Urban and suburban runoff is a major source of phosphorus and other nutrients entering Canandaigua Lake.  Excess nutrients in aquatic ecosystems can cause algae blooms and an overgrowth of aquatic plants.

The Issue:

Phosphorus and other nutrients are important for healthy plant growth however when excess nutrients, especially phosphorus, enter waterways, they can have a negative impact on water quality by creating

 Did you know?  1 pound of phosphorus entering our waterways can result in 500 pounds of aquatic plant growth!!

What’s Being Done:

Phosphorus Ban- It’s the Law:

In 2012 the NYS DEC ban on phosphorus fertilizer for all lawns and non-agricultural turf went into effect to protect waterways across the state, including Canandaigua Lake.  Use a zero-phosphorus fertilizer on your lawn to comply with the law, or, if you use a commercial landscaping company, make sure their fertilizing practices are in compliance with the current law.

Find the full text of the law, Frequently Asked Questions and to learn more, please visit the NYS DEC website at:

Look for a zero-phosphorus lawn fertilizer at local home and garden centers


Erosion & Sedimentation

Erosion posed a threat to water quality by enriching the lake with nutrients such as phosphorus and nitrogen and infilling the bottom substrate of a water body such as Canandaigua Lake or Sucker Brook.

The Issue:

Rain and snowmelt can wash over the ground and pick up loose soil as the water travels overland towards drainage systems, streams or the lake.  This process is called erosion and can result in the deposition of large amounts of sediment in water bodies (sedimentation). The problem is two-fold: nutrients present in soil can result in harmful algal blooms or an overgrowth in aquatic plant growth, and secondly, sediment can fill in waterways, which smothers fish spawning areas, creates shallow areas prone to aquatic “weed” growth, or can impede lake access to the point of requiring dredging.

What’s Being Done:

Clean Sweep: In 20XX the City of Canandaigua purchased a new street sweeper that removes approximately XXXX tons of sediment and debris from roadways annually, protecting Canandaigua Lake from nutrient-rich sediment.



Pesticides are chemical substances used to control or destroy insect and/or plant pests in a variety of settings, including agriculture, around homes or commercial areas.

The Issue:

Pesticide application can result in environmental contamination through diverse pathways.  Some pesticides are persistent for long periods of time and collect in the tissue of plants and animals. Predators feeding on smaller prey accumulate these persistent pesticides. Those organisms higher up in the food chain bioaccumulate these toxins to a level that can alter reproductive success or cause other chronic toxicity problems. Many questions remain about the synergistic or combined effects of multiple toxins and pesticides interacting in a lake environment.  Due to the substantial human health and environmental considerations, prudence dictates that the input of these chemicals into the lake should be minimized as much as possible.

What’s Being Done:

Integrated Pest Management: Integrated Pest Management outlines strategies that represent industry standards and best management practices that protect sensitive aquatic ecosystems. The City of Canandaigua has developed a Turf Management Policy that calls for the application of pesticides only once every 1-5 years as needed. Talk to your commercial landscaper about reducing pesticide applications around your home or business and consider following the City of Canandaigua’s Turf Management Policy. To learn more about Integrated Pest Management practices, visit the Cornell Cooperative Extension Integrated Pest Management website:

Harmful Algal Blooms

Most algae do not impact human health, however, certain types of blue green algae (such as Microcystis), are capable of producing toxins.  When concentrations of these algae are high enough, they can pose a risk to human, pet, and wildlife health. The health threat depends on the type of toxin produced and level of exposure, but can range from skin rashes to liver and neurological problems.

The Issue:

It is well understood that increased nutrient loading from the surrounding watershed directly impacts algae levels.  However, research around the country is trying to determine what conditions trigger the development and release of the toxins in these algae. Federal or NYS guidelines on safe concentrations of blue green algae have not yet been established, though they are underway.  In 2013 and in previous years, Canandaigua Lake has experienced increased algal concentrations dominated by blue- green algae.


In late August of 2013, Secchi disk water clarity readings dropped below 3 meters, raw water turbidity doubled (algae based) and samples analyzed by Dr. Bruce Gilman documented that Microcystis was dominant algae in the water. The increasing dominance of Quagga Mussels along with runoff events has created the conditions for blue-green algae to continue to dominate the algal bio-mass.  Minimizing phosphorus into the lake will be the only manageable way to curtail blue green algae levels.

Algae bloom observed at the north end of Canandaigua Lake in 2009 (photo courtesy of

What’s Being Done:

Long-term Monitoring: Testing for the presence of harmful blue-green algae such as Microcystis is one of the many components of the long-term water quality monitoring program that started in 1995. Further testing when an algae bloom is suspected and communication to the general public is important to minimize the risk of exposure and protect public health.


‘Take a Dip for Canandaigua Lake’ Volunteer Monitoring Program: The Watershed Council has partnered with the Canandaigua Lake Watershed Association to train volunteers to monitor water clarity in different locations throughout the lake, augmenting the monthly data collected in the long-term monitoring program with weekly data from volunteers.  Water clarity can be impacted by both sediment and the presence of algae; however, a rapid decrease in water clarity in the absence of storm events usually indicates the start of an algae bloom.  Further testing can then be performed.

“Take a Dip” volunteer taking a water clarity reading using a Secchi disk.


Invasive Species

Invasive species are plants and animals that exist outside their natural range due to human influence and cause net harm to the environment, the economy and human health.  Common aquatic invasive species already established in Canandaigua Lake include curly-leaf pondweed, Eurasian water milfoil, Aisan clams, Zebra mussels, Quagga mussels and the common carp, to name a few.

The Issue:

Invasive species often outcompete native species as they lack natural predators, thereby disrupting the ecological balance within aquatic communities. They also reduce fish and other aquatic wildlife habitat, replace beneficial native plants, and reduce dissolved oxygen levels. Invasive species impact the economy by clogging waterways, interfering with irrigation, and reducing recreational opportunities for fishing, boating and swimming. Certain invasive species can also impact human health.  For example, Quagga mussels contribute to harmful algal blooms by both feeding on non-blue green algae communities and cycling nutrients into the water column increasing the ability of blue green to grow  These two factors increase the risk of exposure to toxins associated with blue green algae.

What’s Being Done:

Watercraft Stewards Program: The Finger Lakes Institute has worked with communities throughout the Finger Lakes region, including those around Canandaigua Lake, to train Watercraft Stewards work at public boat launches to preventing the spread of aquatic invasive species.  Invasive species can enter the Finger Lakes through multiple aquatic pathways, one of which is moving boats from waterbody to waterbody. The Great Lakes Watershed has 4.2 million small boats, and Canandaigua Lake alone has over 4000 power/sail boats that may be used on other waterbodies. Watercraft can move invasive species if they are not properly cleaned or inspected before each use.  Stewards inspect boats upon their exit or entrance into the water and physically remove any plant and animal material. Stewards also share important information with boaters about preventing the spread of aquatic invasives.


Finger Lakes Institute
Watercraft Steward Program


Observe, ID, & Remove: Early detection of new arrivals of aquatic invasives provides the opportunity to manage the species while eradication is still possible, especially with aquatic plant species. In the summer of 2013, Water chestnut (an invasive aquatic plant) was observed and positively identified in the West River. The established plants were removed and the surrounding location continues to be monitored. Rapid response to a new arrival, as was the case with the Water chestnut, can helps minimize the spread of the invasive species.




Pathogens are disease-causing microorganisms that can be harmful to human health.  Runoff that includes fecal matter from geese, wildlife, livestock, pets and failed septic systems are often the source of these harmful microbes.

The Issue:

Exposure to water that contains pathogens can cause a variety of symptoms, some of which include skin irritation, infections, nausea, vomiting and diarrhea. Often the pathogens originate from wildlife, livestock or human waste that is washed into waterways during storm events. If you have a concern that you may have been exposed to waterborne pathogens, contact your doctor.

What’s Being Done:

Water Testing:  Weekly bacteria sampling occurs at Kershaw Park by the City of Canandaigua, with results indicating consistently low bacteria levels required by the NYS Department of Health for public swimming at beaches. To date, none of the public swimming beaches (Kershaw Park, Canandaigua Town Park, Deep Run Park, Onanda Park, and Vine Valley Beach) or large private swimming beaches (Bristol Harbour Village, Holiday Harbor/Town Harbor Island, Crystal Beach, and Canandaigua Lake Yacht Club) have required closure due to unsafe bacteria levels.Ongoing monitoring will continue.


Toxic Substances

oxic substances are chemicals that can poison and/or be harmful to living plants and animals, including humans. The main toxins of concern in the Canandaigua Lake watershed are various types of pesticides, PCBs, hydrocarbons and benzene.

The Issue:

There are various sources of potential chemical contamination, including inactive hazardous waste sites, petroleum bulk storage, accidental spills, illegal dumping and inactive landfills. Soils, surface water and groundwater can all be contaminated with hazardous wastes, petroleum, chemicals, heavy metals, and other substances.  The impacts of contamination all depend on the pollutant. Contamination can pose risks to public health, making water unfit for drinking or recreation.  Contamination can also degrade wildlife habitat and can be toxic to plants and animals. The Canandaigua Lake watershed has very little industry that would contribute significant amounts of chemical pollutants to the lake. However, individual sites may pose a risk.

What’s Being Done:

Spill Response: For a suspected hazardous waste spill, call:

NYS DEC Spill Hotline: 1-800-457-7362

and Kevin Olvany, Canandaigua Lake Watershed Manager at (585)396-3639

Link: DEC website for recommendations for homeowners


Annual Hazardous Waste Collection: Ontario County holds an annual hazardous waste collection day which provides community members with a safe and proper method to dispose of chemicals.

 Labeling Storm Drains: Storm drains are located in many communities to prevent roads from flowing.  However, they are also a direct link to the lake; storm drain water does not get cleaned, anything that goes down into the storm drain can end up in the lake. The Watershed Council and Canandaigua Lake Watershed Association have worked together to label unmarked storm drains throughout the watershed with student and youth service groups.  To date, nearly 500 storm drain have been labeled with new markers, which serve as a reminder to the general public that anything entering the strom drain system could end up in Canandaigua Lake.

Legacy Pollutants

The NYS DEC describes legacy pollutants as originating from industrial discharges and waste disposal practices prior to the establishment of regulation in the 1960s and 1970s, prior to which a wide variety of toxic compounds were disposed of either directly into lakes and rivers or landfills that leached into waterways.  Many of these legacy pollutants have a tendency to persist in lake and river bottom sediment and also bioaccumulate in fish.

The Issue:

The north end of Canandaigua Lake is an example of a legacy pollution site within the Canandaigua Lake watershed.  In the early 1930s, the area where Lakeshore Drive and Kershaw Park now exist was used as a landfill, as was common practice at the time. A variety of materials were disposed of to fill in the existing wetland, including building materials such as bricks and concrete, and old petroleum storage drums, most of which were empty or nearly empty.  In the summer of 2010, however, small amounts of tar-like substance were found in the Kershaw Beach swimming area.  Extensive chemical testing of this material determined that it was a form of hydrocarbon originating from the 1930s and most likely migrated to the surface from the buried storage drums.  Due to the concern for human health, the entire Kershaw beach area was closed for the remainder of the summer and an extensive remediation project removed the contaminated materials. The beach was restored by filling in the excavated area with new sand and ongoing monitoring will be performed at the site using a monitoring well designed to intercept any subsurface contamination.

What’s Being Done:

Ongoing Monitoring: A monitoring well was created during the remediation process to allow for continued access to the groundwater for testing of hydrocarbons.

bottom of page