Helmut Schmidt, Published January 10 2013
Cold snap could have water mains popping again in Fargo-Moorhead
But major water main breaks, like those seen in Minneapolis, Duluth, Minn., and Sioux Falls, S.D., are less likely every year in the Fargo-Moorhead area because the cities have been steadily replacing cast-iron pipes installed from the 1930s to 1960s, officials said.
Fargo had 75 main breaks in 2012, with about two-thirds of them (48) occurring in July, August and September, said Ben Dow, the city’s director of public works.
July alone had 22 main breaks, he said.
In 2010, the city had 40 main breaks, and there were 45 breaks in 2011.
“We really saw an impact from these dry soils,” Dow said. “It was really strange; we had one almost every day” as soils shifted around pipes, causing them to break.
There haven’t been many water main breaks so far this winter, but the frost is deep – about 4½ feet – due to little snow cover, he said.
With a good cold snap, the frost will get into the 5- to 5½-foot range, he said, and “that’s when we see it popping.”
On the east side of the Red River, 2012 saw 70 main breaks, up from 60 in 2011 and 40 in 2010, said Kris Knutson, the water division manager for Moorhead Public Service.
Moorhead has a main replacement budget of about $350,000 a year, Knutson said.
Moorhead has 206 miles of water piping, with 40 miles of it being cast iron, which is slowly corroding due to the area’s acidic soils.
Moorhead has had a main replacement program since 1984 and replaces a half-mile to a mile of pipe a year, Knutson said.
But some stretches can be much more expensive.
“A four- or five-block stretch of a main transmission line is about a half-million (dollars). It adds up very quickly,” Knutson said.
Fargo plans to spend
$7.4 million this year on six water main projects – about 2.5 miles in all – which also includes street reconstruction costs.
That will be paid with
$3.7 million from Fargo’s infrastructure sales tax, $1.9 million from special assessments on property owners and $1.8 million from utility funds generated by water rates, said Cody Eilertson, a division engineer for design and construction in the city’s engineering department.
Fargo has 475 miles of water mains. Of that, there are 51 miles of cast-iron pipe, Eilertson said. Smaller diameter pipes are replaced with PVC pipe, though large mains, 30 inches in diameter or more, are replaced with ductile iron pipe, he said.
Fargo averages two to four miles of main replacement in a year. That means most or all of the cast-iron pipe should be swapped out in 15 to 20 years, Eilertson said.
Some of the oldest pipe in Fargo is downtown.
Eilertson said some of the mains that will be replaced when First Avenue North and NP Avenue are rebuilt are about 100 years old. The main at First Avenue North near Roberts Street was installed in 1911.
“Anywhere we’re doing a project, if there’s cast-iron pipe, it’s getting replaced,” Eilertson said.
Records show that between 1990 and 1996, Fargo averaged 181 water main failures a year. From 2007 to 2009, it dropped to an average of 84 failures a year.
The highest number of Fargo main breaks was 603 in 1988. The lowest number of breaks since the early 1950s was 24 in 2005, records show.
Unhappy New Year
The focus on the infrastructure under our feet came with three major main breaks in the region.
Two occurred on New Year’s Day.
• In Duluth, a water pipe installed in 1887 burst, pouring 3 million gallons of water on its downtown streets.
• Sioux Falls had a 20-inch drinking water main break in a remote area on the north side of the Big Sioux River near Falls Park. The city lost about 2 million gallons of treated water.
• The big attention-getter was the rupture of a downtown Minneapolis 36-inch main that filled streets with 14 million gallons of water.
That break was caused by a heavy construction machine piercing the line, which was installed in 1890.
Duluth’s Mayor Don Ness said the city spends about $2.3 million annually fixing breaks and leaks in the city’s 426 miles of underground pipes, half of which are more than 80 years old.
Over the past decade the number of water main breaks in Duluth has doubled to about 140 every year.
Duluth now has a plan to slowly replace its aging infrastructure.
A 2007 federal study estimated Minnesota’s drinking water infrastructure needs $6 billion in repairs and upgrades. That doesn’t include needed sewer systems fixes, which state officials estimate at $4.5 billion.
This story includes material from Minnesota Public Radio News.
Readers can reach Forum reporter Helmut Schmidt at (701) 241-5583