Water contamination in Baltimore: What to know about E. coli

City officials over the weekend detected E. coli bacteria in the water supply in parts of West Baltimore. A boil water advisory is in effect while the city searches for the source of contamination.

Here’s what Baltimoreans need know about Escherichia coli — commonly known by its abbreviated name, E. coli.


What is E. coli?

E. coli is a family of bacteria found in food, the environment and naturally in the intestines of humans and animals, said Mary Grace White, director for acute communicable disease at Baltimore City Health Department.

Their presence in the city’s water supply indicates that the water might be contaminated with human or animal wastes, according to a news release from the city’s Office of the Comptroller.


“The test that they are reporting or that they routinely test is a water quality test. So the E. coli coliform, that’s a standard public water testing, which basically is to determine whether the water is contaminated with fecal matter,” White said.

The CDC said E. coli can enter the water supply from sewage overflows, sewage systems that are not working properly, polluted stormwater runoff or agricultural runoff. Much of Baltimore’s water and sewer infrastructure is quite old, and failures such as sewage spills and water main breaks are common.

What are the symptoms of having E. coli?

E. coli is often spread during contact with feces and some strains are harmless and play a role in maintaining a healthy intestinal tract in humans while others are pathogenic, White said.

“Typically, the way humans are exposed is by swallowing or eating or drinking something that’s contaminated with a pathogenic E. coli bacteria,” she said. “And usually, symptoms cause gastro-foodborne kind of gastroenteritis illnesses, which are fever; diarrhea, sometimes bloody; vomiting; nausea; stomach pains.”

Those are the more severe presentations of the infection, White said. Human pathogens in these wastes can cause other short-term symptoms including nausea and headaches, the news release states.

Illness caused by the bacteria usually is mild and clears up on its own, but in rare cases, a potentially life-threatening complication can result about a week following the initial infection, according to the U.S. Centers for Disease Control and Prevention.

E. coli might pose a greater health risk for infants, young children, the elderly and people with severely compromised immune systems, according to the city.

What to do if you feel ill

Adults who become ill from the bacteria are encouraged to call their doctors if diarrhea lasts longer than three days, is bloody or is accompanied by a fever higher than 102 degrees, or if vomiting is so severe that patients can’t keep liquid down.


For infants and children, a health care provider should be called right away if the child has a fever of 102°F or higher, seems tired or very irritable, is in a lot of discomfort or pain, has bloody diarrhea or seems dehydrated.

“If there are any symptoms, that is concerning; definitely reach out to their health care provider. They would know best your status, your health,” White said.

Boil water or obtain bottled water.

White said people should not ingest any water tap at this time, and this includes from icemakers and water dispensers.

Residents living in the impacted area need to boil water for most water uses. Water should be brought to a full, rolling boil for at least a minute and then cooled before using, according to the CDC.

The CDC recommends using boiled or bottled water for drinking, making ice, brushing teeth, feeding pets and preparing or cooking food. Filtered tap water also should be boiled.

As of Tuesday afternoon, there are three water distribution sites in West Baltimore.


This story might be updated.