Water Quality Update for September 3, 2021

  • Water Quality Update for September 3, 2021
  • Monitoring of Public Drinking Water Systems
  • Recent rains and duckweed
  • DEC Gill Netting: Keep an eye our for the orange buoys
So far this week:
  • 22 surveys performed
  • No Blooms reported
Current Lake Conditions
Through our monitoring network of watershed staff, Canandaigua Lake Watershed Association volunteers, and reports from the general public – we have had zero blue green algae (cyanobacteria) blooms this week. Overall, water clarity is holding in the 5.5- 6.0 meters as measured by a secchi disk, which is good for this time of year.
Since mid- August, we have also sampled open water levels of blue green algae on a weekly basis at nine locations in the northern third of the lake (historically the area with the highest open water concentrations). We have been trying to sample on days when we are getting reports of shoreline blooms and conditions are ripe for potential open water blooms. Results from our August 28th sampling showed blue green algae levels that ranged from 0.33-1.86 ug/L with an average of 1.05 ug/L. The DEC threshold for a bloom is 25 ug/L. We also sampled at three of these locations for the microcystin toxin that can be produced by blue green algae. Two of the results were less than the 0.3 ug/L detection limit and one sample was 0.31 ug/L. The DOH threshold for re-opening a beach is less than 4.0 ug/L. We are very pleased with these results thus far. We will continue this sampling effort through early October.
Deep Run beach in the Town of Gorham, which is an Ontario County Park, was closed last weekend due to blue green algae. The NYS Department of Health tested the water quality of the beach on Monday, August 30th and the results indicated that the beach could be reopened. However, as with many of the other public beaches – lifeguard staffing issues may not allow Ontario County to re-open Deep Run. Please remember that if there is no lifeguard on duty, no swimming is allowed at public beaches.
Monitoring of Public Drinking Water Systems
The six Canandaigua Lake water purveyors (the City of Canandaigua, the Village of Newark, the Village of Palmyra, the Village of Rushville, the Town of Gorham, and Bristol Harbour) are working alongside the New York State Department of Health to monitor the public drinking water for the presence of toxins associated with harmful algal blooms. Samples are collected of both raw (untreated) and finished (treated) water on a weekly basis for microcystin (the toxin that can be produced by blue green algae). All results to date have come back as undetectable. The water purveyors will continue to sample on a weekly basis through early October. Weekly results are posted on the CLWA website and can be found here.
The above water quality observations and data are very promising this week. However, it is important to remember that conditions can change quickly on the lake. Typically, we have seen our most significant bloom events in the early to mid-September timeframe. Please use your visual indicators before entering the lake. Look for discolored water, surface streaking of blue green algae (cyanobacteria) or pea soup conditions.
If you have a question on a suspected bloom, please feel free to send in a photograph to HABs@canandaigualakeassoc.org. This email address is monitored by CLWA and Canandaigua Lake Watershed Council staff. We may be able to assist with identification though a clear photograph.
Volunteers and watershed staff will be continuing daily observations throughout September and early October, and we will communicate any significant changes in bloom activity through our weekly email updates, on our website, and on our facebook page.
Enjoy Labor Day weekend and consider using LED flares for the Ring of Fire!
Recent rains and duckweed
Just a reminder that with the recent rain events, we may continue to observe mats of floating duckweed / watermeal. This past Sunday the Naples area was hit again with a significant thunderstorm that caused flooding conditions. The stream flows from Naples Creek and the West River ultimately flows through the High Tor wetland system. This wetland system supports a tremendous amount of duckweed and watermeal (harmless tiny aquatic plants) as part of this ecosystem. The major streamflows pushed much of this duckweed and watermeal into the lake.
While duckweed itself is harmless, many other items including debris and blue green algae can sometimes get caught up in these dense mats, so please use caution if boating or swimming in them.
DEC Gill Netting : Keep an Eye out for the Orange Buoys
DEC Aquatic Biologist Pete Austerman reached out to let us know that the DEC will be doing more gill netting on Canandaigua Lake during the weeks of September 6th and September 13th. They will be using fine mesh gill nets to monitor forage fish populations (primarily alewife and smelt). Boaters may observe orange buoys and will want to avoid the nets as some of them are near the surface and could get caught in boat props.