Bacteria sampling in Sloans Lake is conducted at two week intervals from April through September at
four sample locations. The state's water quality guidance for bacteria is based on
E. coli concentrations which are measured in "colony forming units" (cfu) per 100 milliliters (ml). The advisory level of 235 cfu/100ml that DEH uses as a benchmark is based on the
Colorado Department of Public Health and Environment's guidance.
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Sampling Sloans Lake bacteria levels in 2011 began April 20th and will continue at two week intervals through September. Data will be compiled and presented as it is collected. Here are the latest sampling results for 2011:
While there have been no exceedances of the swim beach guidance of 235 cfu/100ml in 2011, our long term monitoring results indicate that there are typically elevated water column bacteria levels for 24 to 48 hours following moderate to heavy rainfall events. We advise caution if choosing to recreate in Sloans Lake within 48 hours of a rainfall. Rainfall measurements from the area can be obtained from the
Community Collaborative Rain, Hail, and Snow Network website.
Sampling for the 2010 recreation season was conducted at two week intervals from May 25th through September 16th. There was one exceedance of the swim beach advisory level at one site in mid-July. This sample day was preceded by two days of light to moderate rainfall.
Elevated bacteria levels may occur at any time and may cause illness.
What if bacteria levels exceed the state advisory?
When E. coli levels exceed the state guidance level of 235 cfu/100ml, there is an elevated risk of sickness as a result of water intake. Typical symptoms include nausea and gastrointestinal issues.
When the advisory level is exceeded, City personnel will update the yellow informational sign at the boat dock with a red cautionary version. This diamond shaped advisory informs recreationist that recent findings indicate elevated risk based on the most recently measured bacteria levels. The sign will be replaced with the yellow information version when monitoring results indicate bacteria concentrations are below the state advisory level.
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Last updated 6/20/11