Bursting Pipes & Opportunistic Pathogens

These Water Stories Can Teach Us A Lot About Our Struggling Systems

New York City. The city that never sleeps. Sometimes, because a 127-year-old water main breaks at 3 a.m. under Times Square, flooding midtown streets and the city’s busiest subway station.

Gah!

Last week, a 20-inch (half-meter) pipe burst under 40th Street and Seventh Avenue.

This is why infrastructure is so important, friends! We forget about what’s under our feet and the age of these systems. There’s about 1.6 million miles of water and sewer pipes in the United States that help deliver our drinking water to homes, schools, and businesses.

The average age of our municipal pipes is almost 50 years old. The cast iron pipes in at least 600 towns and counties are more than a century old, according to industry estimates.

That cast iron pipe in NYC was actually built to last about 120 years, so it was more than past its prime. And just think about what the city was like more than a century ago versus now. That’s a huge demand for an old pipe!

Once it broke, water rushed into the Time Square subway station, flooding stairwells and soaking train platforms.

It took crews about an hour to find the source of the leak and shut the water off, according to Rohit Aggarwala, commissioner of New York City’s Department of Environmental Protection.

Surrounding streets had a few inches of water too, but were open by rush hour. Subway service was suspended through much of Manhattan on the 1, 2, and 3 lines, which run directly under the broken pipe. About 300,000 people rely on those lines during a typical morning rush hour. Service was restored later that day.

New York City has about 6,800 miles (10,900 kilometers) worth of water mains, enough pipe to stretch from Times Square to Tokyo, according to the Associated Press, and has spent $1.9 billion in the past three years upgrading outdated water and sewer lines.

But breaks are pretty normal for the city, happening almost every day. Last year, 402 water main breaks occurred, which was the second lowest number on record.

New York is not alone in this issue.

Although much of historical New Orleans is beautiful, the age of the water pipes is nothing to celebrate. More than half of the city’s 1,530 miles of water mains were installed before World War II; a third were installed before Prohibition. Philadelphia still uses water mains installed before the Civil War.

Chicago has about 400,000 lead service lines, which the city is working to replace. The total cost of the project is about $8 billion, which has left the Chicago Water Department with challenges for replacing the pipes quickly and equitably.

As we’ve discussed before, ongoing infrastructure issues, lack of resources, misappropriated funds, and shortsighted decisions go right along with toxic contamination to impact our water supply each day.

A 2021 report from the American Society of Civil Engineers estimated a water main break every two minutes in this country. The cost for replacing all these aging pipes will be more than $1 trillion. 

These breaks are caused by many factors, including changes in temperature, corrosion, and deterioration of old pipes.

One pipe rupturing can impact the whole water distribution system. Repairing these breaks usually requires the water to be shut off, and during that time contaminants can enter the water supply.

It’s easy to take clean water for granted until it’s suddenly not there, or it’s rushing through the streets and into our public transit systems.

Learn more about the C- we received on our Infrastructure Report Card here.

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What’s an Opportunistic Pathogen?

In mid-August, the U.S. EPA announced it was awarding almost $8.5 million in grant funding to four institutions for research on the occurrence and concentration of pathogens and disinfection by-products and the environmental conditions favorable to their growth in drinking water distribution systems.

It’s about time, as these issues continue to grow! (pun, intended).

Let’s talk first about disinfection byproducts (DBPs). In the ‘70s, scientists discovered that chlorine (a water disinfectant) could react with naturally occurring materials in the water to create what are called DBPs.

These are substances that form when the disinfectant reacts with natural compounds in the water. Many of these DBPs have been shown to cause cancer, including trihalomethanes (THMs), which are a group of chemical compounds.

Today, we have more than 1,000 cities with unsafe levels of total THMs (TTHMs) in their water. TTHMs form when four distinct chemicals, chloroform, bromodichloromethane, dibromochloromethane, and bromoform, are present. Any imbalance of THMs means the system is out of balance.

These compounds occur when organic matter in the water reacts with chlorine, so essentially the system is not being chlorinated properly, meaning you have too much or not enough.

But many cities don’t get to the root of the problem by finding the source of the organic matter. When you know what’s in the water, you can treat it more effectively instead of creating a chemical cocktail mix.

In the last 40 years or so, we have discovered more than 600 DBPs in chlorinated tap water, including haloacetic acids (HAAs). As you can imagine, the water has only become more polluted (with both organics and inorganics), creating more treatment headaches and violations.

The EPA has worked to regulate DBPs with the adoption of the EPA Stage 1 and Stage 2 Disinfectants and Disinfection Byproducts Rules (DBPRs). These rules help to tighten drinking water regulations, requiring water treatment systems to monitor and reduce DBPs so they can provide cleaner drinking water.

Unfortunately, many cities and towns use chloramines to fix their DBP problems.

This alternative disinfectant method is a mixture of chlorine and ammonia. Water treatment facilities have been switching at alarming rates from chlorine to chloramines, largely to help public water systems meet federal disinfection byproduct requirements. I would say it’s a convenient fix, but not necessarily a safe or effective one. Chloramine treatment is the cheapest way of meeting EPA regulations, but it’s one of the most dangerous ways as well.

I’m glad to see the EPA funding more research to improve our understanding of how to control these contaminants and help inform water infrastructure management and risk-mitigation practices to ensure cleaner drinking water for all.

Now, let’s talk about opportunistic pathogens (OPs), such as Legionella, mycobacteria, and Pseudomonas. They can all grow in drinking water systems and pose potential risks to public health, according to the EPA’s press release.

The occurrence of these and other microbial pathogens is also associated with contaminated storage facilities and other problems in water distribution systems such as backflow and low-pressure incidents.

When left untreated, these contamination events can lead to outbreaks of gastrointestinal and other waterborne illnesses.

One person whose been studying OPs is Jade Mitchell, associate professor in the Michigan State University Department of Biosystems and Agricultural Engineering (BAE). She has looked specifically at waterborne pathogen risk levels in low-flow plumbing.

“Water conservation has been mainly driven by the energy policy, and not on how we treat and store water,” Mitchell said in an MSU publication. “What's happening—is that due to water conservation and low-flow fixtures, we're using less water—so our water is being stored longer in the pipes and that allows for leaching of chemicals and growth of pathogens.”

Opportunistic pathogens can manifest in these low-flow systems. They can also cause infections in people with sensitive immune systems, including individuals with an existing disease or illness, children, the elderly and pregnant women.

“Opportunistic pathogens tend to grow in situations where other pathogens don't, so like we set our water heaters at a certain temperature so that people aren't scalded, but they're not high enough to kill these pathogens,” Mitchell said.

It’s important to know about OPs, especially if you’ve been on vacation or out of the office for a few weeks.

“I think that utilities (companies) tell people if you're on vacation, when you come back, you really should flush your water lines before you use them, but how much time it requires depends on what that whole pipe network looks like, like ‘how big is the building?’,” Mitchell said. “What we're hoping is that this research helps offer some better guidelines for what to do.”

Her work continues as she received more than $2 million to better understand and predict occurrence of DBPs, OPs, and the associated health risk tradeoffs posed by them in drinking water distribution systems across the country.

The following institutions are receiving EPA awards for further study:

• University of Minnesota, Minneapolis, Minn., to develop strategies for limiting exposure to OPs and DBPs and generate new data on OP and DBP occurrences in U.S. water distribution systems, including understudied small systems in rural Alaska that serve economically disadvantaged native populations.

• Michigan State University, East Lansing, Mich., to better understand and predict occurrences of DBPs, OPs, and their associated health risk tradeoffs. Project outcomes will support better evaluation, monitoring, and risk management strategies in drinking water distribution systems across the U.S.

• University of Texas, Austin, Texas, to conduct a nationwide study of contaminants across a wide variety of drinking water distribution systems and help identify occurrence patterns of OPs and DBPs. Research will demonstrate how health risks are correlated with general water quality and distribution system factors to inform strategies that will reduce risks to people from drinking water.

• Georgia Tech Research Corporation, Atlanta, Ga., to monitor the drinking water microbiome and manage pathogen and DBP risks in drinking water storage and distribution systems. The project will also assess pathogen and DBP impact on the availability of safe water to inform appropriate health risk interventions.

Learn more about the grantees.

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Let’s continue the conversation below! Do you know how old the water pipes are in your neighborhood? Have you heard of OPs?