During the summer of 2019 a total of 180 water samples were collected from the upper watershed swimming sites and analyzed for E. coli. Of these, 4% (n = 7) exceeded the single-sample recreational water standard for E. coli (235 MPN/100 mL). This number was the lowest frequency of exceedances since the program began.

All the sites are used by the public for recreational purposes, especially on the weekends and holidays. As a result, the TSG required that most samples be collected on weekend days, holidays or days following either of these.

On the map to the left you can explore the locations and bacterial concentrations at each of the sites during the previous year. Also, to view the raw data for the samples collected in 2019 and previous years, go to the Data Portal on this website.

What were swimming conditions during the summer of 2019?

During the summer of 2019 a total of 180 water samples were collected from the upper watershed swimming sites and analyzed for E. coli. For the most part swim sites were relatively safe with only 4% (n = 7) exceeding the single-sample recreational water standard for E. coli (235 MPN/100 mL). Of these exceedances, three occurred at station SGUT210 (n = 3) on the West Fork below the North Fork confluence, and two occurred at SGUT206 (n = 2) on the East Fork at Cattle Canyon. Recreational use at each of these sites is heavy, especially on the weekends and holidays.

Levels of bacteria measured across all sites were greatest on the weekends and holidays. Of the seven exceedances, two occurred on weekdays. However, one of these occurred on July 5th, the day after the July 4th holiday. All other exceedances were on weekends.