The following is a letter written by Keith Van Ness, Senior Water Quality Specialist at the Montgomery County Department of Environmental Protection, in response to a question about the safety of water in Sligo Creek:

There is no one that can guarantee that a stream in Montgomery County will be okay and safe all the time. There is no easy “fits all” answer to your question and in the end it is really your decision to let your children swim or to determine how far they can wade in the stream.

The primary concern is bacteria. The two biggest sources of bacteria in urban streams like Sligo Creek are pet waste and wildlife. In undisturbed areas the bacteria would be absorbed and filtered by the ground. Because of the large impervious areas created by pavement and asphalt there is no way for the bacteria to be filtered and so the level of bacteria in an urban stream can be elevated, especially after a rainfall event.

Having said that, I have spent over 20 years working in the streams of Montgomery County – I have waded in them, gotten very wet, and even fallen in – and I would suggest a few simple kind of common sense precautions for you to consider for your children:

1. I believe that, generally, children should be able to wade up to their knees or thighs – but no farther.
2. If they have cuts, abrasions, sores – they should not get those wet.
3. When they are done wading – have them use an antibiotic soap or gel (these come in pump bottles and are readily available) to thoroughly clean their hands before they eat or touch their eyes, nose or mouth.
4. Go home and have them shower and wash their clothes as soon as you can.
5. We have been monitoring streams all over the county for over 10 years now – crews regularly use the pump gels before they eat lunch and avoid hand to mouth contact until they have used the gel as much as possible. Before they go into the stream, they walk up and down the stream reach and visually examine it to see if anything warrants their concern – they also will see if any unusual smells or colors are present. If in doubt, they stay out.

The Montgomery County Department of Environmental Protection is working on ways to reduce bacteria in our streams. It will take time and considerable resources to restore our urban stream…”

Thanks,

Keith Van Ness
Senior Water Quality Specialist
Montgomery County, Maryland Department of Environmental Protection