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Tests confirm water at Harbor Tunnel building tainted with Legionella

But they stop short of saying contamination source of two employees' Legionnaires' disease

State health officials say they cannot determine if two employees working at the Harbor Tunnel contracted Legionnaires’ disease at the facility despite finding the bacteria in the building’s water system.

Test results released Friday by the Maryland Department of Health found the bacteria in water samples taken from the Harbor Tunnel Administration building more than two weeks ago.

“Nineteen of 28 samples tested positive, all at very low concentrations,” according to the report. “Based on these results, MDH cannot determine whether the two employees diagnosed with Legionnaires’ disease acquired the disease at the building or from another source.”

Officials closed the building and toll booths on July 9 following reports that two unidentified employees had been diagnosed with Legionnaires’ disease.

During the closure, transportation authority officials ordered the sterilization of the water systems before reopening the buildings to employees.

“The results of follow-up testing for Legionella bacteria from water collected July 12, 2019 from this building – after water treatment had proactively been performed – showed significant improvement,” according to the health department report. “Only 1 of 28 sites tested positive for Legionella, again at a very low concentration.”

The report recommended “a comprehensive water management program for this building to ensure that the improvements from the recent water treatment are maintained.”

Legionnaires’ disease is a bacterial pneumonia caused by inhaling the legionella bacteria, which sometimes is found indoors in water systems, according to the Mayo Clinic. The illness is not transmitted through person-to-person contact.

Symptoms include headaches, chills, muscle aches and a fever of 104 degrees or higher.

The disease was first identified in 1976 after an outbreak at an American Legion convention in Philadelphia.

As a precaution, Maryland Transportation Authority officials closed the administrative building at the Harbor Tunnel as well as its toll facilities for nearly three days. Tolls were collected as usual from E-ZPass customers. Cash customers were allowed to drive through the toll plaza and were mailed a bill from the state’s video toll system.


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