Update: Since this article was published the boil-water advisory was lifted after the city tested more than 100 water sites throughout Baltimore and did not find evidence of E. coli or other bacteria.

What areas are still under a boil-water advisory?

A portion of West Baltimore remains under a boil-water advisory, spanning from North and South Riggs Avenue to West Franklin Street and East and West Carey Street to Pulaski Ave. These boundaries encompass the three sites where contaminants were first detected, one of which still tested positive for E. coli on Wednesday. This area is a significant reduction from the area placed under a boil-water advisory on Labor Day, which encompassed areas south and southwest of Route 40, as well as a swath of Baltimore County.

Mayor Brandon Scott announced that it was lifting its advisory in much of the precautionary zone at a press conference on Wednesday night, following a series of tests in the lifted area that all came back negative for E. Coli and coliform. Testing in this area never returned positive bacteria results and was only included as a precautionary measure, the mayor said.

You can find an interactive map of the city’s boil-water area on the Department of Public Works website

When will the boil-water advisory end?

City officials have not identified a specific date or date range for the end of the boil-water advisory. The advisory will be lifted once the city can identify the source of the contamination and receives two negative tests in a row for sites in the impacted and precautionary areas, the mayor’s spokesman Jack French said in a statement Thursday.

What do we know about how this happened?

Unfortunately, not very much. The mayor’s office and the city’s Department of Public Works are still investigating the source of the contamination by “surveying and sampling additional locations, working to identify construction projects in the area, performing leak tests, conducting valve assessments and checking chlorine levels,” French said. On the first day of the boil-water advisory, DPW Director Jason Mitchell ruled out the city’s three drinking water filtration plants, as well as its troubled Back River and Patapsco wastewater treatment plants.

While we wait for an official explanation, The Baltimore Banner has been speaking with experts about some of the most likely causes. They agreed that the contamination was likely a localized issue, based on the close proximity of the detection points. One likely explanation is that there was a break in a pipe somewhere close to the detection sites, either due to the age of the pipe or to construction- or demolition-related damage. That break, combined with a loss of pressure or chlorination — possibly stemming from leakage or an issue at a pumping station — could have allowed seepage of contaminated liquid, perhaps from a nearby sewage line or on the street, into the water pipe.

An internal report distributed to agency heads and obtained by The Baltimore Banner notes the positive tests occurred after a pumping station in Mount Vernon was taken offline on Aug. 26, and Public Works received a positive coliform reading “shortly after.”

“The theory is that no pumping resulted in low chlorination in the distribution system,” the report says.

Still, officials have declined to elaborate on possible causes. At a news conference on Wednesday, Scott responded to the Mount Vernon pump station event, saying the city “is not going to be talking about theories.”

“Anything that you hear from us is going to be about facts that we absolutely know through the science,” he said. “We cannot afford to go off theories.”

How does Baltimore keep its water safe?

Baltimore’s drinking water system is fed by a network of reservoirs north of the city, including Loch Raven and Prettyboy, and water from these reservoirs travels across the city via a network of pipes.

Upal Ghosh, a professor at the University of Maryland, Baltimore County, said the city uses two main tactics to guard against the kind of contamination seen this week. First, local pumping stations keep the water moving through the system at high pressures, ensuring that the flow is too strong to allow contaminants to seep in, even where there are inevitable leaks in valves or piping.

The other “line of defense,” Ghosh said, is chlorine. The chemical purges bacteria from the water but also decays over time and must be maintained at a high level. In response to the discovery of E. coli and coliform this week, Baltimore has been has been flushing the system and adding extra chlorine.

Could this happen again?

It’s hard to speculate about whether there could be another E. coli contamination without knowing what caused this one. But water infrastructure experts we spoke with say that Baltimore’s aging infrastructure is vulnerable to a number of challenges.

“This is kind of a signal or a flare that we should be paying better attention to the water supply in Baltimore,” said Dillon Mahmoudi, a professor of Geography at the University of Maryland, Baltimore County.

Baltimore has been widely regarded as a national leader in supplying clean drinking water, becoming a model for other cities. But the likelihood of problems has increased as the system ages, Ghosh said. The average age of the city’s water mains is 75 years, with many over 100 years old. Many pumping stations have also “seen better days,” Ghosh said.

“A lot of this infrastructure lies underground — out of sight, out of mind — and there is clearly need for big investment in infrastructure all over the city,” he said.

What is the city doing to invest in its water system?

In part because the infrastructure is largely buried underground, upgrades to city’s water systems can be extremely expensive. Local governments around the country are anticipating major windfalls from the $550 billion Infrastructure Investment and Jobs Act — funding Baltimore hopes to score, in part, for investments in its aging water and sewer systems.

Baltimore has put $2 million into an office overseeing the city’s applications for federal infrastructure funding, and City Administrator Chris Shorter told City Council members at an August hearing that the city is holding off on investing its federal COVID-19 relief money in needs like water, roads and bridges because of the anticipated funding out of the infrastructure bill.

Without major investment, the city is struggling to complete large scale infrastructure replacement.

“The city is in a cat-and-mouse game of basically whack-a-mole: Find a leak and fix it,” said Natalie Exum, an assistant scientist in the department of environmental health and engineering at the Johns Hopkins Bloomberg School of Public Health.

At the same time, Baltimore is in the process of some significant water system improvement projects. The city is currently installing two massive underground water tanks and covering a portion of Druid Lake to protect the drinking water supply there in accordance with federal regulations. The project was slated for completion in March 2022, but remains under construction.

How do Baltimore’s water challenges compare to other cities?

This week’s water safety scare comes as tens of thousands of people in Jackson, Mississippi, another majority Black city, were without clean water over the last week.

The crisis playing out in the Mississippi capital stems from decades of disinvestment and urban depopulation, and Exum stressed that West Baltimore’s boil-water advisory “is not what happened in Jackson.” While Baltimore has seen similar population declines, its drinking water system has historically been well managed and has not experienced the systemic failure and the “vicious cycle” of a diminished ratepayer base that Jackson has seen, Exum said.

While it’s not exactly common for E. coli to show up in municipal drinking water, it’s not unheard of, said Steve Via, director of federal relations for the American Water Works Association, the trade association of water-supply professionals.

In recent weeks, communities in Harris County, Texas, Jacksonville, Florida, and Doña Ana County, New Mexico have advised residents to boil their water following positive test results for E. coli.

“The thing to keep in mind about E. coli is it’s an indicator that every water system across America monitors for frequently,” Via said. “That creates opportunities for catching something.”

Where is the city distributing water to residents?

The Department of Public Works is distributing water at three sites: Harlem Park Elementary/Middle School (1401 W. Lafayette Ave.), Middle Branch Park (3301 Waterview Ave.) and Lansdowne Library (500 3rd Ave.)

Banner reporter Tim Prudente contributed to this article.

adam.willis@thebaltimorebanner.com

sophie.kasakove@thebaltimorebanner.com

Read more:

• Officials reduce boundaries of boil-water advisory and announce plan to discount water bills citywide by 25%
• Baltimore’s pandemic aid money could be ‘life-changing.’ How will the city measure the success of its spending?

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