Environmental Services

Volunteer Stream Monitoring

 

Arlington's Office of Sustainability and Environmental Management coordinates the volunteer stream monitoring program. After participating in a County-sponsored training, stream monitors wade into Arlington's streams and report back important environmental data that the County uses to monitor the long-term trends of our streams. The citizen-collected data is also reported to the state of Virginia as a part of our MS4 Permit.  

How Healthy Are Our Streams?

The addition of surfaces that do not allow water to soak into the ground, like roads and buildings, have a significant impact on stream health. Within Arlington County, roughly 42% of the land has been converted to impervious surfaces, surfaces like roads, sidewalks, and buildings that do not allow water to soak into the ground. As a result of the our urban environment, Arlington's streams are generally in fair condition. The stormwater runoff that enters our streams increases stream temperature, causes flash floods - significant increases of water that occur in a short period of time after a storm, increases the sediment and pollutant loads.  The County is implementing stream restorations, Green Streets, and the StormwaterWise Landscapes program  to reduce runoff. There are many things that homeowners can do to reduce runoff! 

Volunteer Stream Monitoring Programs

  • Macroinvertebrate Monitoring.  Macroinvertebrates are small organisms that live underwater in our streams, can be seen with the naked eye, and lack a backbone.  These "stream bugs" live a portion of their life cycle in the streams and depend on our streams for habitat and food.  Some macroinvertebrates are more tolerant of stream pollution than others, which makes them good indicators of water quality.  If the macroinvertebrates found in the stream are the types that are more tolerant of pollution, it is a sign that the stream is impaired.  If you find a good variety of macroinvertebrates in the stream, it can indicate a healthy stream.  Macroinvertebrate monitoring is also helpful to compare a stream's health before and after a stream is restored, or pollution prevention practices are put in place. If a stream used to only have a few bugs living in it, and now has more types of bugs present, this indicates that the stream's health has improved.
  • Bacteria Monitoring.  Since 2005, Arlington volunteers have been collecting water samples and testing them for E. coli on a monthly basis.  The program was developed to identify hots spots, areas with high bacterial levels, and to help with identify potential sources of bacteria.  The County collects the citizen data and provides it to the Virginia Department of Environmental Quality and the Virginia Department of Conservation and Recreation as a section of our stormwater permit report.   

For more information on becoming a volunteer stream monitor, please contact Jen McDonnell at (703) 228-3042.

View data from both of these monitoring programs below, by clicking on the maps of the sites!   

Map of Arlington macroinvertebrate mapping sites
Macroinvertebrate Monitoring Sites. Click on the map to enlarge.  Link to site data by clicking on the enlarged map's pushpins.
 
Monitoring locations with a street overlay. Click to enlarge and view the PDF.
 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Bacteria Monitoring

E. coli is a type of bacteria that is found in the digestive tract of warm-blooded animals such as people, dogs, cats, raccoons, and birds. If high levels of E. coli are found in a stream or river, there is the potential for disease-causing pathogens to also be present. In 1996, Four Mile Run was listed as an impaired water for E. coli and a Total Maximum Daily Load (TMDL) was later established for the nontidal portions of Four Mile Run. Further information about the Four Mile Run TMDL can be found on the Northern Virginia Regional Commission website

The County uses the Coliscan Easygel kit with its volunteer program. This kit is recommended for citizen monitoring by the Virginia Department of Environmental Quality.  Since 2005, Arlington volunteers have been collecting water samples and testing them for E. coli on a monthly basis. The County collects the citizen data and provides it to the Virginia Department of Environmental Quality and the Virginia Department of Conservation and Recreation. The Coliscan Easygel test results are not laboratory quality, but they have been shown to be a reliable indicator to determine if further testing or investigation is warranted. This form of testing is low cost and provides an efficient method to narrow the search area for potential bacteria sources.  

Where is the bacteria coming from?

  • Concentrated wildlife. In an urban area, wildlife are often concentrated in park areas that are near streams. 
  • Storm sewer systems can provide a habitat for bacteria to reproduce underground in the pipes. Ultraviolet light (sunlight) kills bacteria.
  • Sanitary sewer pipe breaks or leaks.
  • Pet waste. Picking up after your pet (cat and dog) is a public health issue, not just one of courtesy to your neighbor.

What do high bacteria levels in the water mean to me?

High levels from the Coliscan Easygel indicates that there is a greater possibility that illness-causing pathogens could be present in the water. It does not guarantee that the water will make you ill, but the high level is a sign that additional care should be taken. Always wash your hands after working or playing in our streams.

Should I be worried?

No.  Activities that involve touching the water are safe, such as skipping rocks or water monitoring. You should always thoroughly wash your hands afterward coming into contact with the water.  Never drink stream water. The County does not recommend performing activities, like swimming, in our streams that result in submerging your body so that water can enter your nose, eyes, ears, and mouth. Learn more about enjoying streams safely!

Is the Volunteer Data Available?

Yes. The data is available in the Annual Stormwater Management Program Report and through the map below. Click on the map and then on the individual monitoring sites to reach the bacteria data from 2008 through the present.

  

E. coli Monitoring Sites.  Click on the map to enlarge. Link to site data by clicking on the enlarged map's pushpins.


Last Modified: November 12, 2013
2100 Clarendon Blvd. Arlington, VA 22201 Tel: 703-228-3000 TTY: 703-228-4611