See Source Info tab to understand what these results mean
Passed water quality tests 60-95% of the time
This status is based on the latest sample, taken on August 3rd, 2026
Upper St. Lawrence Riverkeeper
updates the status of this beach as soon as test results become available.
These results were posted to Swim Guide on August 6th, 2026 at 15:49.
Monitoring Frequency:
Round Island is sampled
Weekly from
July 3rd
to
August 28th.
Water Quality Graph:
About Round Island
Round Island is an island within the Thousand Islands that is situated to the East of Clayton. There is no exact swimming area on Round Island but the water off the West side of Round Island is tested because it is a popular swimming spot for boaters and those on the island.
Current Weather
25°C
Partly cloudy
Source Information
Recreational public beaches in upstate New York are tested at least once every week typically from mid-June to September. Freshwater beaches in New York are posted when a single sample exceeds 235 E. coli / 100 ml or when the geometric mean of samples collected over a 30-day period exceeds 126 E. coli / 100 ml. Chapter I of the State Sanitary Code Subpart 6-2 includes more criteria for freshwater quality, but most monitoring agencies rely on the E. coli standard.
