Two of three Baltimore sites that originally had E. coli contamination in water have since tested negative, officials say

Director Jason Mitchell, Baltimore City Department of Public Works, answers questions about E. coli contamination found in the water in parts of Baltimore.

Two days after the city first announced that E. coli had been found in tap water samples taken in West Baltimore, two of the three sites where the bacteria were first found now show negative results, officials said Wednesday.

The city Department of Public Works first discovered the bacteria in water samples taken from Sandtown-Winchester and Harlem Park over Labor Day weekend. On Monday, Public Works told residents across a large swath of West Baltimore and southwestern Baltimore County to boil their water.


The city is still working to determine the source of the E. coli, which can cause intestinal problems, and the water boil advisory remains in effect, Mayor Brandon Scott and city officials said at a Wednesday afternoon news conference.

Of the 25 new samples the city collected between Monday evening and Tuesday morning, one sample showed a positive result for E. coli, Public Works Director Jason Mitchell said.


The positive result came from a police facility at 1034 N. Mount St., one of the three sites that first showed E. coli over the weekend. The other two sites, a fire station at 1503 W. Lafayette Ave. and a building at 920 N. Carey St., showed negative results when retested.

Mitchell said his department is taking eight samples every eight hours in the impacted zone, and some more of those results were expected Wednesday afternoon. The department is sampling 90 areas inside and outside the impacted zone, Mitchell said, and that work is expected to conclude by the end of Thursday.

The problem appears isolated to one particular zone of the city’s sprawling water system, fed by reservoirs in Baltimore County and treatment plants at Lake Ashburton and Lake Montebello. The water is safe to use in the rest of city, officials said.

On Labor Day, the Department of Public Works issued a required boil water advisory for an area of about 56 city blocks surrounding the fire facility where the first positive sample came from. A precautionary boil water advisory was issued for a much larger area of West Baltimore, and extending south into Baltimore County, including Lansdowne and Arbutus.

It’s recommended that residents in both affected areas boil water for one minute before using it for activities such as drinking, teeth brushing or preparing food. Residents may bathe in the water, but must avoid swallowing it, so officials have recommended that guardians sponge-bathe young children.

In addition to the sampling, Public Works staff are working to identify the contamination’s cause by looking at construction projects, testing for leaks, performing valve assessments and checking chlorine levels in the area.

After a reporter at Wednesday’s news conference inquired about a water pumping station taken offline for repairs Aug. 26, Mitchell said it was one of many possible theories for the contamination that officials are investigating. The station, which was taken offline for a valve replacement Mitchell called “critical,” is now back online.


No illnesses stemming from the contamination have been confirmed, though Baltimore Health Commissioner Dr. Letitia Dzirasa said Wednesday that the health department was investigating two cases of gastrointestinal illnesses reported within the affected area to determine whether the individuals had been infected with E. coli.

“The health and well-being of our residents remains our top priority and we will keep working diligently to determine the source of the contamination,” Scott said.

Dr. Letitia Dzirasa, Baltimore's health commissioner, right, answers questions about E. coli’s effects.

The city has been distributing water at several pick-up points in the affected areas and, to date, has distributed about 53,000 gallons of bottled water, said James Wallace, deputy chief of the Baltimore City Office of Emergency Management.

During Wednesday’s news conference, Scott urged residents who need bottled water delivered to their homes to dial 311 to schedule a drop-off.

“We have heard the concerns of our residents around accessibility,” Scott said.

Scott also addressed concerns that his administration has been slow to communicate about sampling results, saying that results take 24 hours, and then city officials must talk through the data with officials from the Maryland Department of the Environment before notifying the public.


“We’re going to continue to follow that, because that’s the regulation,” Scott said.

The E. coli contamination was first discovered after results came back Saturday from routine water testing performed Friday at the fire station on Lafayette Avenue, Mitchell said. The Department of Public Works then conducted additional testing to confirm the positive result and that revealed more positive results at the nearby buildings Sunday, Mitchell said.

Monday morning, the department issued several tweets sharing the positive results, saying that residents in an unspecified geographic area “may want to consider boiling any water from faucets.” The department said it also posted information on the NextDoor neighborhoods website and sent representatives into the community.

But residents and elected officials decried the unclear communication before the city issued a map later Monday afternoon depicting the extent of the boil water advisory.

Baltimore Mayor Brandon Scott’s image is reflected in a news camera eyepiece during Wednesday's news conference.

The boil water advisory area is in the western side of the city’s “Second Zone” for drinking water distribution, according to the city’s water and wastewater plan. The water in that zone flows by gravity from the Lake Ashburton water treatment plant, according to the plan, but it is also pumped in from several pumping stations, which draw treated water from storage areas elsewhere in the city.

The city operates three treatment plants in total, which draw water from three reservoirs outside the city: Loch Raven, Prettyboy and Liberty.


Officials have maintained that the water flowing from the city’s three treatment facilities is clean, and the most recent report that they submitted to the federal Environmental Protection Agency, which dates to 2021, shows the facilities in compliance with regulatory limits.

The problem, then, is likely downstream, somewhere in the network of pipes that deliver water from the treatment facilities to the faucets of West Baltimore, said Natalie Exum, assistant scientist in the department of environmental health and engineering at the Johns Hopkins Bloomberg School of Public Health.

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The water flowing through those pipes is supposed to be very pressurized, Exum said, so that if there’s a crack in the pipes, water flows only out — not in. Given that Baltimore’s water pipes are an average of about 75 years old, leaks are fairly common. So, maintaining high water pressure is especially critical. A drop in pressure, however fleeting, could have opened the door to contamination from fecal bacteria in the environment.

Exum said she wouldn’t compare Baltimore’s problems this week with larger water crises in Jackson, Mississippi, and Flint, Michigan, because they are not systemwide.

“Leaks happen all the time. Pressure changes happen all the time, which is why I’m not as quick to jump to the: ‘Jackson, Mississippi, Flint, Michigan ... conclusion,” Exum said.

Jackson, for instance, is in its sixth week of a boil water advisory after flooding cause problems at its water treatment plant leading to inadequate water pressure.


Boil water advisories are hardly rare, either, Exum added. On Tuesday, Beaver Falls, Pennsylvania — a city of about 9,000 people northwest of Pittsburgh — issued such an advisory after a water main break caused water pressure to plummet. In late August, part of Jacksonville, Florida, came under a brief boil water advisory when E. coli was discovered in well water.

Regardless, the emergence of a drinking water crisis centralized in an already disadvantaged Baltimore neighborhood is “a bad look,” Exum said. The census tracts in the boil water advisory area, located in Harlem Park and Sandtown-Winchester, have a median household income of about $26,000 annually, according to 2020 census data.

“This is burdening an already burdened community,” she said.