America’s bridges, dams, roads and water mains are aging fast. The need to upgrade the national water system is of particular concern, as we depend on it for clean, fresh water. Every year close to 2.1 trillion gallons of water are lost in the U.S. due to leaking mains.

How much will it cost to upgrade all of those leaky pipes? $1 trillion to replace the nearly 1 million miles of aging mains coast to coast, according to the American Society of Civil Engineers. In Maine alone that cost would be $1 billion. In Bangor, where the water district board recently approved a rate increase, the cost for a full upgrade would be close to $200 million. And the city wouldn’t get to that point for 400 years at the current rate of replacement.

Most of the state’s water systems were built in response to the growth and economic development of the late 1800s and mid-1900s, according to the Maine Public Utilities Commission. But a wide variety in the quality of materials used to build the systems means many pipes are reaching their breaking point, regardless of their installation date.

A mile at a time

Beneath Bangor run more than 200 miles of pipes that carry fresh water across the city. For many, replacement is past due.

According to the Bangor Water District, the average lifespan of Bangor’s water pipes is about 100 years. But about 60 miles of pipes are more than 100 years old. Some have been in use since they were installed in 1875. Replacing them takes time — and it likely won’t come anytime soon.

And that’s not unusual in Maine. Most Maine water systems aren’t being replaced fast enough, according to the Maine Section of the American Society of Civil Engineers. In Maine, large water systems on average replace about 0.7 percent of their pipes each year, which means it would take 110 to 150 years for a full replacement cycle.

“We can replace a half mile of pipe each year,” Bangor Water District General Manager Kathy Moriarty said. That’s 0.25 percent of the entire network.

At that rate it would take 400 years to replace each mile of pipe. In order to sustainably renew the water system, Bangor would have to quadruple its current rate of replacement and lay down two miles of new pipe every year.

But achieving a 100-year replacement cycle costs more than the water district can afford, Moriarty said.

To “close the gap,” the water district board of trustees in mid-March approved a 9.8 percent rate increase, a change that will generate $553,000 annually for an infrastructure renewal account. If the water district gets the go-ahead from the Public Utilities Commission, that rate would likely go into effect this summer.

The extra money will allow the water district to double its current effort and replace a mile of pipe per year, reducing the city’s 400-year replacement cycle to 200 years, according to Moriarty.

Pipe triage

Last summer the Bangor Water District upgraded sections of pipe underneath Main Street, West Market Square in downtown and elsewhere across the city. Some of the pipes replaced in West Market Square dated back to the Civil War. All told, 1.4 miles of pipes were replaced for a total of $2.3 million, allowing the city to pull ahead of its usual half-mile-per-year replacement rate.

That was still a drop in the bucket.

The water district can prioritize what pipes to replace based on age, leak history and water quality issues, Moriarty said. In the case of last summer’s work, it made sense to collaborate with the city of Bangor and the Maine Department of Transportation to replace pipes where construction crews were already tearing up roads, she said.

By partnering with Bangor and the Department of Transportation, the water district was able to save money, especially with paving — one of the more costly chores when replacing pipes.

But often, it’s not easy to know when a pipe needs replacement. “Sometimes it takes a failure,” Moriarty said. “We can only guess at the condition of it.”

Fixing a leak

Every year there are nearly 240,000 water main leaks in the U.S., an average of 657 every day, according to the American Society of Civil Engineers.

In 2014, Bangor saw 21 leaks and lost 4.2 million gallons of water. And that was below Bangor’s average of about 30 main leaks each year. Bangor has already reached 18 leaks in the first three months of 2015. The most recent main break was on Court Street on March 25. “Typically we have a lot of main breaks in the winter,” Moriarty said, and this winter has been exceptionally tough on the old pipes.

The water district spends close to $100,000 a year repairing leaks in the water pipes, and the cost of repair can vary greatly. For example, a leak on Cumberland Court on June 25, 2014, cost $549, while a leak on York Street a week later cost $12,799 to patch. Moriarty said the city’s most expensive main repair back in 2001 cost $130,000.

The York Street leak left 100 residents without water for 23 hours. Earlier in 2014, on May 23, a leak behind the water district’s business office caused flooding that shut down part of State Street, Moriarty said. These leaks were on pipes that were 105 and 64 years old, respectively.

Joint corrosion

The pipes of most concern aren’t necessarily the oldest. They’re the cast iron pipes joined with leadite, a sulfur cement that took off around World War I when lead was in short supply (leadite contains no lead) and was commonly used until the 1970s.

Bangor installed about 41 miles of cast iron pipe with leadite joint seals during that five-decade span. This method was considered a cheaper and high-quality alternative to lead — a December 1916 article in the American Water Association Journal declared that “a leadite joint once declared tight would be good for all time” — but leadite actually corrodes joints over time, increasing the risk of leaks.

In 2002, the Environmental Protection Agency found that “the failure rate in the industry for leadite joint pipe is significantly higher than for lead joint pipe even though the pipe may not be as old.”

With that lesson learned, since 1973 the water district has installed 53 miles of ductile iron pipe, which uses a rubber gasket to seal joints as opposed to corrosive leadite. This type of pipe also uses a cement lining to prevent the corrosion that unlined cast iron pipes suffer.

Another option the water district has pursued to save money and extend the life of the older cast iron pipes is to reline them with a corrosion-preventing epoxy.

“Our focus for the last 100 years was building pipes,” Moriarty said. “Now we have to repair them.”