OCEAN CITY — After water from a fire hydrant tested positive for the presence of legionella, the bacteria associated with Legionnaire’s Disease, in late September, the latest batch of samples taken following the discovery have come back negative and no legionella has been detected.
On Sept. 25, a water sample taken from a hydrant on 145th Street tested positive for legionella. The discovery came on the heels of a positive test for legionella at a nearby hotel earlier in September after two reported cases of Legionnaire’s Disease were linked to the lodging establishment.
The positive test for legionella in the north end fire hydrant set in motion a larger effort to identify and contain the source and the extent of the possible exposure. The Worcester County Health Department and the Maryland Department of the Environment (MDE) worked closely with the town of Ocean City and more samples were taken earlier this month.
A total of six new samples were taken, including a sample from the hydrant that indicated the first positive result along with five other locations in the vicinity. Those new samples were tested extensively and came back with negative results. The latest batch of samples, tested by the Maryland Department of Health and Mental Hygiene (DHMH) last week showed no evidence of the presence of legionella, according to Ocean City Communications Manager Jessica Waters on Monday.
“The reason for the samples was to monitor more closely and comprehensively so as to determine the extent of absence of this microbe within the distribution system,” she said.
In advance of the test results, the town enhanced its usual safety precautions in the event of a positive result. Waters explained normal water department operations involve the addition of chlorine at the treatment plant for disinfection purposes and for monitoring the distribution system for the level of chlorine residual that is present in treated water.
The department maintains a chlorine residual in the distribution system to safeguard the town’s water from excessive microbial growth. In response to the concerns presented by the initial positive legionella test, the water department increased the amount of chlorine in the system to further safeguard against any microbial growth.
While the Town of Ocean City worked closely with its county and state partners after the initial positive test, no restrictions were placed on water use at any time, nor were there any major concerns with public safety. With the negative results returned on the latest batch of samples released late last week, the town no longer has any concerns about the presence of legionella in the water system, although the normal safety and monitoring procedures will remain in place.
“At this time, the water department will continue to work closely and cooperatively with the MDE and Maryland DHMH to ensure the safety of Ocean City’s water supply,” she said.
Waters said local residents and visitors should be reminded hydrant flushing of the town’s water system will begin later this month and is a routine operation not related in any way to the initial positive legionella test. The hydrant flushing, which is done bi-annually, will progress from south to north beginning at South 1st Street on Oct. 26 and will cover several blocks per day.
Residents and businesses are reminded that following the flushing there might be a slight discoloration of the water. The discoloration is not harmful and will dissipate after a short time. Residents and businesses are advised to run cold water for several minutes until the water runs clear to clean their pipes. The entire project is expected to be completed before Nov. 1.