Legionella Bacteria Found In Water At Howard County Schools

HOWARD COUNTY, MD — Water contained in cooling towers for Howard County Public Schools has tested positive for legionella bacteria. As a precaution, the school district began voluntarily testing its water in September. Proactive sampling is not required by federal, local or state regulations, officials confirmed. A press release updated Oct. 21 by the school district stated the water that tested positive "is not drinking water or water that is used for any other purpose."

The district said is not uncommon to find various legionella species in building water systems. There are at least 50 legionella species, only 20 of which cause human diseases. The presence of the organism cannot be directly equated to a risk of infection. However, the detection of the genus legionella at elevated levels (above 100 colony forming units) "suggests additional treatment and maintenance is warranted," the district stated in a release.

According to the Centers for Disease Control and Prevention, legionella bacteria can cause a serious type of pneumonia called Legionnaires’ disease if actually consumed. The bacteria also can cause a less serious illness called Pontiac fever. Symptoms include coughing, shortness of breath, fever, muscle aches and headaches. Legionnaires’ disease can also be associated with other symptoms such as diarrhea, nausea and confusion. Symptoms usually begin two to 10 days after being exposed to the bacteria, but it can take longer so people should watch for symptoms for about two weeks after exposure, the CDC said.

If elevated levels are found by the school district in follow-up testing, remediation efforts will include additional chemical treatment and maintenance, such as super chlorination. Monitoring is done with confirmatory sampling. Any schools where positive results are found will proactively communicate with their school communities.

The district will continue to test all cooling towers annually in the fall when the water in the cooling towers can be idle for extended periods of time due to low cooling load conditions. The school system takes sampling from every cooling tower located at:

• Atholton Elementary School
• Atholton High School
• Department of Education building
• Centennial High School
• Clarksville Elementary School
• Cradlerock Elementary School/Lake Elkhorn Middle School
• Dunloggin Middle School
• Forest Ridge Elementary School
• Hammond High School
• Harper’s Choice Middle School
• Howard High School (ground cooling tower)
• Howard High School (roof cooling tower)
• Laurel Woods Elementary School
• Long Reach High School
• Marriotts Ridge High School
• Mt. Hebron High School
• Oakland Mills High School
• Oakland Mills Middle School
• River Hill High School
• Reservoir High School
• St. John’s Lane Elementary School
• Talbott Springs Elementary School
• West Friendship Elementary School
• Wilde Lake High School