Residents and motorists in two areas of Northeast will have to deal with some inconvenience this spring and summer, and the payoff is expected to be cleaner water and about 50 years added to the useful lives of their water mains.
While the work is going on, residents and businesses in the affected areas won’t get their water through the main line that runs from the street to their water meters; instead they’ll get water through their outdoor faucets from a hose that runs to a larger plastic pipe line that will run along the curb in front of buildings. City plumbers will make special connections for buildings that don’t have outdoor faucets.
Outdoor faucets will be fitted with a Y-shaped adapter to allow for water to come into the building, and to allow for outdoor watering.
The work is planned for Johnson, Lincoln, Buchanan and Pierce streets between Lowry Avenue and 29th Avenue NE; plus some of the blocks on 26th, 27th and 28th avenues between Johnson and Pierce; and for Roosevelt, Taft and Wilson streets between 22nd Avenue NE and Lowry, plus 19th Avenue between Stinson Boulevard and Coolidge Street, Walden Place, and Coolidge Street from Walden Place to Lowry; plus 22nd Avenue between Stinson and Coolidge.
City officials call the process “cleaning and lining,” and it’s designed to deal with deterioration in the sometimes century-old unlined cast iron water mains in the area. A letter to residents from Robert Ervin, an engineer in the City of Minneapolis Water Treatment and Distribution department, says that over time, “unlined cast iron mains build up rust deposits on the inside, which decreases the flow of water and [the water] has a less pleasing appearance. We will scrape the rust out of the pipes and install a liner that keeps the water clear and prevents new rust from forming.”
While the work is going on, water will not be flowing through water meters, so “the City will bill your property for water use based on your use in previous years.”
City crews have already begun digging holes (mostly at intersections) and cutting out sections of water mains where contractors will do the cleaning and lining work. “Pipes will be opened every 600 to 750 feet in the project area. It takes much longer to prepare the holes than it takes to actually clean and line the pipes, so the holes must be excavated up to a few weeks in advance. This insures that the cleaning and lining contractor can work continuously without delay once they arrive on the site.”
This year, the city is contracting with Heitkamp Inc., a Connecticut- and Maryland-based firm, to do the cleaning and lining work. Ervin said in an interview that the city has worked with other firms in previous years.
He said the city samples water at various locations to determine “which [mains] are worse than others,” and they become the priority locations for each year’s cleaning and lining work. The city has about 750 miles of unlined cast iron water mains, and can clean and line only about 10 miles per year.
“Last year we didn’t do any at all,” he said, because of budget problems. In most years, he said, the city spends about $4 million on cleaning and lining.
He said the city saves a lot of money by doing the cleaning and lining rather than replacing the corroded mains. He said it costs about $350 per linear foot to replace water mains, including excavation and street repair. The cleaning and lining runs $60 per linear foot.
He also noted that the cleaning and lining option is only workable in water mains that are structurally sound.
For more information, contact the city’s Water Treatment and Distribution department at 612-673-5600.