Remediation Efforts Will Be Conducted Over the Weekend; New Water Management System Will Be Installed In Coming Weeks

BALTIMORE, MD (Friday, February 21, 2025) - Today, the City of Baltimore announced the following update on ongoing building water quality concerns in Baltimore City facilities.

Precautionary testing in three Baltimore City courthouses indicated elevated levels of legionella bacteria in the Baltimore City District (People's) Courthouse at 501 E. Fayette Street, Clarence M. Mitchell, Jr. Courthouse at 100 N. Calvert Street, and Elijah E. Cummings Courthouse, at 111 N Calvert Street. This secondary testing was ordered on 2/11/2025, and results were received on 2/21/2025.

Due to the elevated levels of bacteria found, the City will be conducting mitigation efforts, including flushing and chlorination treatments, over the weekend.The City has taken these steps, including the precautionary testing that discovered the elevated levels and the robust mitigation efforts, out of an abundance of caution. Water usage signage will be placed throughout the building.

As this is the second discovery of elevated levels, the recent mass cleaning of the system effectively eliminated 98% of the Legionella bacteria. However, there may be a variety of factors that contribute to this issue, such as dormant sections in the system and potential cracks within the pipes, creating an opportunity for Legionella bacteria to spread over time even after successful mitigation efforts.

The age of the buildings and the design of internal plumbing systems in the courthouse are likely contributing factors to the repeated presence of elevated levels of legionella bacteria. In order to address this, the City will be installing additional mechanical water management systems that prevent bacterial growth. These systems use high purity ammonium salt and stabilized chlorine solutions for the safe production of monochloramine. Both chemicals are dosed in the production reactor by means of precision electronically-controlled dosing pumps. The microprocessor manages all the production, control, safety and alarm features of the unit. The technology guarantees the optimal balance of reagents and ensures the system cannot overfeed.This state-of-the-art system is the same design utilized in hospitals and other sensitive locations that are prone or vulnerable to elevated bacteria levels. The City will continue to monitor the situation over the coming months to determine if more extensive mitigation efforts need to be conducted.

Minimal Impact on Broader Water Distribution System

The City's public distribution system, like most municipal systems, is designed to keep water in constant motion and includes chemicals - namely chlorine - specifically designed to prevent bacteria growth, making the typical conditions for the presence of legionella bacteria unlikely. While there is no requirement for a public water system to test for legionella, out of an abundance of caution, DPW has conducted tests on the level of chlorine in the system in the impacted areas since these concerns arose in an effort to entirely rule out concern about the City's system. The chlorine levels signify whether legionella can grow. So far, the chlorine residual levels in the surrounding areas have been tested and are sufficient.

Current Status of Health Concerns

The Baltimore City Health Department (BCHD) has not received any reports of confirmed cases of Legionnaires' disease related to elevated levels of the bacteria in City Buildings. BCHD will continue to monitor for relevant reports and work in coordination with the Maryland Department of Health to address any concerns as they arise.

Additional Background on Legionella Bacteria & Related Health Concerns

Legionella is a bacterium that can be found in many natural and man-made water systems. The most common way for someone to get sick is by breathing in small droplets of water contaminated with legionella that is sprayed in the air (i.e. water mist or vapor). Most healthy people exposed to legionella do not get sick.

Individuals who do get sick experience symptoms including cough, fever, headache, muscle aches, and shortness of breath. If you are experiencing symptoms of pneumonia (cough, fever, shortness of breath, chest pain), contact your healthcare provider. There are many forms of pneumonia, and respiratory infections with symptoms that overlap with pneumonia. Your health care provider can help determine the cause of your symptoms. Urine tests or sputum tests are the best tests to diagnose Legionnaires' disease. Note that blood tests are usually not as helpful in diagnosing Legionnaires' disease.