DULUTH – Utility supervisor Daniel Berg sees evidence of leaking, cracking water pipes all over the place when he drives through his beloved city.

"There's a dig. There's a dig. There's a dig," he said in staccato succession as he cruised down Piedmont Avenue, pointing out each asphalt patch as evidence of repairs made deep underneath streets. In some recent years, his crews have repaired nearly 300 leaks, and in Berg's mind the city can't replace the aging pipes fast enough. He's grateful, he said, that Duluth is stepping up efforts toward that goal.

"We've been replacing about a mile and a half a year," Berg said, adding with a chuckle that it was a multi-century replacement plan "on a system that's designed for 100 years."

In Duluth and many cities across Minnesota, leaders are tackling the formidable task of replacing leaky water pipes, deteriorating sewer lines and other aging out-of-sight, out-of-mind infrastructure that, in some cases, has been patched for decades. Though the Legislature infused nearly $122 million into the stream of money available for water projects last year, it was just a drop in the bucket of a more than $11 billion need over 20 years for Minnesota cities, according to estimates from two state agencies.

Regardless of how much state or federal money is available, projects typically involve hefty local funding, too, soaking water and sewer users with bigger bills.

"Cities are getting to the point where, really, it's costing them a lot of money to deal with it in a piecemeal fashion, and they're sort of facing up to and taking on these larger projects," said Jeff Freeman, executive director of the Minnesota Public Facilities Authority, which administers state grants and loans to cities for infrastructure.

Costs going up

The reason so many cities are tackling the issue now, Freeman said, "is just the timing."

Much of the infrastructure across the state was built in the 1930s and '40s under the Works Progress Administration and after World War II. It's simply wearing out. So, too, are treatment plants added in the 1970s and '80s, when federal grants for wastewater treatment were up for grabs, he explained.

Clean water has also taken on increased importance in recent years, for public health, the environment and economic vitality. Modern water quality standards are prompting upgrades to facilities, too.

The longer cities wait, mayors and administrators know, the costlier the work and the greater the sticker shock.

"We can't wait. It'll just cost us more. Materials go up. Labor costs go up. Standards change," said Granite Falls Mayor Dave Smiglewski, who serves as president of the Coalition of Greater Minnesota Cities.

A Minnesota Department of Health report estimates that drinking water infrastructure in the state will need $7.4 billion in improvements over 20 years, about $4.6 billion of which will need to be spent on replacing old pipes.

Of an estimated $4.2 billion needed for wastewater projects, according to the Minnesota Pollution Control Agency, about 40 percent will need to go toward rehabbing existing sewer systems. More than half of the overall need is in greater Minnesota, where the population is more sparse and infrastructure upgrades are more expensive per capita. Small towns are sometimes eligible for extra help through grants from the state and the U.S. Department of Agriculture, however.

In addition to funding some individual projects, the Legislature appropriated nearly $106 million in bonding for water projects last year, and the state's Clean Water Fund added another $16 million. It was an amount far above the previous 10-year average of just over $30 million per year.

Local leaders are seeking a similar infusion this year.

"You need to pass several years worth of bonding bills with that level of funding in order to begin to meet these needs," said Bradley Peterson, a lobbyist for the Coalition of Greater Minnesota Cities. "It is a lot more money than we've had in the past, but we need a lot more."

Funding the work

While the city of Duluth relied heavily on grants and loans for a massive upgrade of its wastewater system several years ago to meet environmental standards, it is now trying to replace water pipes without much outside help.

The Duluth Public Utilities Commission recently decided to increase water volume rates for its customers by 4.7 percent per year over the next six years, for an overall bill increase of about 28 percent. That should allow the city to replace about 4.3 miles of pipe per year, or 1 percent of the system, said Eric Shaffer, chief engineer of utilities.

In Minneapolis, water pipes are in "really good condition" compared to older systems, spokeswoman Sarah McKenzie said. But 80 percent of the city's sanitary sewers are more than 80 years old, and after using cameras to check the lines for cracks, roots and other obstructions, the public works department is asking the city to increase its sewer rehab funding by more than $4 million a year, to $11.5 million, which would be covered by a rate increase.

At the St. Paul Regional Water System, where half the 1,200 miles of water pipes were built before 1950, the administration has a goal of replacing 1 percent of the system each year, though it is replacing about .6 percent right now, said public information officer Jodi Wallin.

The system operates without state or federal grants, and rates are proposed to go up by 3 percent next year for various maintenance, operations and replacement needs. The city's sewer system is also being replaced on schedule without state or federal grants, spokesman Joe Ellickson said.

Utility pipe replacement is often done most efficiently as streets are repaired and rebuilt.

Federal and state grants came to the rescue for the 130-some households and businesses in Echo, a small prairie town in southwest Minnesota. When Yellow Medicine County decided to redo the main thoroughfare through town, city officials decided it was the right time to replace the town's water and sewer pipes and make other upgrades, to the tune of more than $4.5 million.

About three quarters will be covered by grants, but that still leaves the locals with more than $1 million in low-interest loans to pay off through increased rates over the next 40 years.

Checking for leaks

In Duluth, where the city's steep topography and rock and clay geology mean more line breaks than in many other cities, utility crews play a version of water main Whac-A-Mole, checking reported leaks and bursts.

The basic water system was laid in the late 1800s and early 1900s. Since then, electricity in many buildings has been grounded to the water pipes, a common practice in many cities. Pipes get eroded in spots where electricity travels into the soil, Utility Operations Supervisor Chris Kleist said.

Members of Duluth's "Leak Seek" crew travel to reported leaks and pull out special equipment to place atop a hydrant, pipe or valve. One of the crew members uses headphones to listen for a change in a what sounds like static, signifying a leak in the pipe six feet or more below. A computer helps them pinpoint the leak's location.

Digging to repair a leak costs $5,000 to $7,000, supervisors said.

Just before midnight recently, a crew worked under spotlights at 40th Av. W. and Grand Av. to replace a leaky valve. The digging was relatively easy; in the depths of winter, it can take more than an hour to dig through a foot of frost.

After a backhoe removed scoops of brown soil, one crew member climbed into the hole to chip remaining dirt from the valve. Water sprang out in several directions. "There's the leak!" he yelled.

Crew members who work on pipes in any city know where the trouble spots are and understand the looming price tags to replace infrastructure. Residents don't think about it, they said, until suddenly they have no water pressure in their faucets.

"It's been delayed for so long," utility operations lead worker Daral Lange said as he peered down into the hole. "Out of sight, out of mind."

pam.louwagie@startribune.com 612-673-7102