Businesses along a historic street in Minneapolis were soaked early Thursday when a water line broke in the middle of the night, the fourth major break of a water pipe in Minneapolis in just over a year.
The break of the private water line — between the city main and the businesses — points to the aging private pipes that bring water to thousands of businesses and homes in Minneapolis. Many of the water mains and the service lines in the city are close to a century old.
The break occurred along St. Anthony Main, just across the Mississippi River from downtown Minneapolis. It's one of the oldest parts of the city, with some buildings dating to the 1850s.
"Our infrastructure is getting older and older, and we need investment," said Seth Spychala, president of the Minnesota section of the American Society of Civil Engineers. Age matters, he said.
Clay or cast iron meets old ground
First, older water mainlines are typically made of clay tile, which is more brittle, or cast iron, which is subject to corrosion. Older pipes also lie in ground that's had more time to settle or be invaded by tree roots over time. Today's ductile steel pipes are stronger and less brittle, he said. Typically, utilities are designed for a 50-year life, which means that much of Minneapolis is well past that. Some city water pipes are nearing 150 years old.
Water service lines from city water mains to private properties are aging along with those mains, and about 300 annually need to be replaced, according to Bernie Bullert, the city's director of water treatment and distribution.
That's the responsibility of the business owner or homeowner, and a typical residential service line replacement costs $3,000 to $5,000, he said. Typically the oldest homes have lead pipes as small as five-eighths of an inch in diameter, and a typical replacement line is 1-inch copper pipe that can better handle the demands of washers and dishwashers. The city requires replacement of lead lines.
The biggest indicators that a line may be leaking is water running down the street or diminished flow inside the building.