General Information for Lake Merced Boaters

Individuals who use Lake Merced for boating purposes are urged to be cautious and to use common sense about contact with such water. Officials from the San Francisco Department of Public Health caution that it is impossible to guarantee that any natural body of water is free of risk from disease causing-organisms or injury. All rivers, streams and lakes contain naturally occurring algae, bacteria, viruses and parasites. Microbiological organisms can also come from pet waste, birds, and human sewage. The concentrations of such organisms may be increased from runoff into Lake Merced for several days following rainfall because runoff can introduce bird and animal waste into Lake Merced.  Most of the time, Lake Merced water quality meets full body contact standards.  However, lake water quality can sometimes exceed full body contact standards. Given that swimming is prohibited at Lake Merced, such exceedance does not pose a significant health risk. The following suggestions are made to protect recreational boaters who may accidentally come into contact with the water:
·    Persons whose immune systems are compromised should be careful to avoid swallowing water from any river, stream or lake.
·    Prevent broken skin from directly contacting the water in Lake Merced, especially after a rain event.
·    After boating in Lake Merced, wash your hands with soap prior to eating.
·    Any boater who accidentally falls into Lake Merced should shower with soap as soon as reasonably possible.
·    Do not add to the risk; use appropriate toilet facilities.

For additional Information Contact:
Environmental Health Section
City and County of San Francisco Department of Public Health
1390 Market St, Ste 910
San Francisco CA 94102
phone: 415-252-3973