This is the 34th year for SRA's Operation Clearwater, a water quality monitoring program that provides waterfront communities on the Severn River with regular updates of the microbial water quality at their waterfront recreational areas. We will identify those times when it may be inadvisable to swim. Our member, Dr. Sally Hornor, of the Environmental Center at Anne Arundel College, will again supervise Operation Clearwater. She may be reached by phone at AACC at 410.777.2842 or via email at clearwater@severnriver.org 

Operation Clearwater monitors water quality by enumerating a group of bacteria collectively known at the enterococci. These bacteria, like the fecal coliforms counted in the past, are associated with fecal waste of warm-blooded animals, birds and mammals. These bacteria in themselves are not harmful to swimmers but they do indicate the presence of recent fecal contamination of water. When the number of enterococci exceeds 104/100 ml, there may be other microorganisms present in that water which could cause illness, such as gastroenteritis and ear infections. It is generally recommended by the U.S. Environmental Protection Agency not to swim in water containing enterococci counts that have an average value exceeding 35/100 ml or a single sample result of more than 104/100. Thus counts that exceed 104/100 ml are highlighted in red on this web site. For more information about the EPA method and interpretation of results, visit this EPA document.

The counts of bacteria in water are always variable. The number of enterococci/100 ml will vary greatly depending on rainfall. Once we have received enough rain to cause substantial overland flow into our creeks and rivers, generally about one-half inch of rain, bacterial counts will tend to rise sharply and will remain high for 24-48 hours. This is especially true in areas where runoff flows down streets directly into creeks and rivers. For this reason, rain data are included in this report when we have had at least 0.5" of rain within the watershed 24-48 hours previous to sample collection. Of course, summer thunderstorms are notoriously spotty, and we measure rainfall in Arnold. A brief but intense storm in Annapolis or in Millersville may not even be recorded. Samples are collected on Wednesday mornings between 7 am and noon from land at the community's waterfront facility. Data are posted at this web site by Thursday afternoons. If the number of enterococci exceeds 104/100 ml, Operation Clearwater Community Representatives are notified by phone or email.

A 14 week schedule costs $360 and runs from mid-May through August while a 7 week bimonthly schedule costs $185. This cost includes $25 per sample plus a one-time charge of $10 for the SRA. Contact Dr. Sally Hornor at the number or email given above for more information or to sign up for sampling. For your convenience, an application can be downloaded here:

Operation Clearwater 2008 Application

Operation Clearwater Results

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