With summer upon us, residents are getting out and enjoying our parks and streams. Many of our parks are places where you can easily forget that you live in a densely populated, urban community. While we encourage you to enjoy our parks, remember that stormwater flows directly, untreated, into Arlington streams. Sometimes pollutants also wash into our storm drains and streams (such as paint, concrete wash, sawcut slurry, pet waste, cleaners, and more).
Key Tips for Enjoying Streams Safely
Our streams are generally safe for superficial contact – like fishing or walking in the water.
- Do not ingest stream water or submerge yourself in stream water.
- This includes drinking the water or getting water in your eyes, ears, nose or mouth.
- Open sores should not come into contact with stream water.
- Do not swim and bathe in our streams.
- After touching stream water, always wash your hands with soap and water.
- Children who are too young to understand and follow these precautions shouldn’t be allowed to play in our streams.
If the Water is Clear, It Isn’t Necessarily Clean
You cannot see bacteria or other pathogens in the water. You cannot assume that water is clean and suitable for play just because it is clear.
Absolutely! Remember that when dogs enter a stream, their eyes, nose, mouth and ears are in close proximity to the water. It would be hard for them not to ingest the water. As a result, any pollutants and pathogens in our streams will be consumed by the dog. Many dogs will also lick their paws or fur after leaving the water and will ingest the water that way as well.
Where Do the County’s Stream Recommendations Come From?
Scientists have determined what levels of bacteria in a water body are safe for various activities, and have developed “water quality standards” to help protect human health. These standards help monitoring agencies determine if it is safe for people to have full contact with the water, like swimming.
Water quality standards have been amended through the years as better science has become available. Bacteria has been used since 1914 as an indicator of water quality.* Today we have a bacteria standard based on Escherichia coli (E. coli) levels. Four Mile Run and Little Pimmit Run have been listed by the state as waters that are impaired due to bacteria, meaning that there is too much bacteria in these waters for people to safely swim or do other activities where water may be ingested. Based on the water quality standard and how Arlington’s streams have performed in relation to this standard, we only recommend superficial contact.
Related Web Pages
* Source: Lawrence, S.J. 2012, Escherichia coli Bacteria Density in Relation to Turbidity, Streamflow Characteristics, and Season in the Chattahoochee River near Atlanta, Georgia, October 2000 through September 2008-Description, Statistical Analysis, and Predictive Modeling: U.S. Geological Survey Scientific Investigations Report 2012-5037, 81 p., available online at http://pubs.usgs.gov/sir/2012/5037/.