E. coli bacteria levels are used as an indicator to assess the health of a waterway for recreation.  E. coli is found in the waste of warm blooded animals and although many strains of E. coli are not harmful themselves, they can indicate the possible presence of microorganisms such as other bacteria, viruses, or parasites that can cause illness.  The test results are compared to state standards for recreation and if bacteria levels exceed this standard, the risk of contracting waterborne illnesses increases.  Usually, we see elevated bacteria levels right after heavy rainfall due to runoff from the streets and hillsides, and during prolonged droughts due to the concentration of contaminants during low flow conditions. 

Bacteria test results are just one piece of information to consider before you decide to jump into the river.  Here are some tips to keep in mind for healthier swimming this summer:  

1. Don’t swim in water that is stagnant, looks discolored, murky, or smells unpleasant. 
2. Avoid digging in or stirring up sediment.
3. Avoid getting water up your nose - wear nose plugs or hold your nose.
4. Avoid swimming if you have an open wound or infection. 
5. Use appropriate toilet facilities.  Do not put yourself or others health at risk by using waterways as a toilet. 
6. Don’t leave litter behind – take all your trash with you when you leave. Especially dirty diapers.  
7. Don’t swim in areas with flocks of ducks and geese.
8. Wash your hands before eating and shower when you are done swimming. 
9. Use caution when swimming after heavy rainfall. Contaminants can be washed into the river.  Also, cloudy water will hide hazards such as logs, branches, broken glass, and metal.  We recommend waiting approximately 5 days after heavy rainfall (rainfall that produces significant runoff from streets/hillsides into river) to resume swimming.

And remember…you are the best person to decide if it is safe to swim at a particular swimming spot.