Crews try to clear up St. Cloud’s drinking water with a whole bunch of ice

A small river of reddish-brown, icy water was poured down the street in St. Cloud’s Canoe Creek Lakes neighborhood Tuesday morning, and though it may not be the prettiest sight, city crews hope it’ll help clear up the dirty water that’s plagued residents for years.

The draining water is the result of the process called "ice pigging." 

It’s an experimental process that city leaders are trying to clear up the water coming out of local faucets.

A river of reddish-brown, icy water flows from the pipes of a St. Cloud neighborhood being ice pigged.

"It’s [the ice] basically scraping the inside of the pipes,” said St. Cloud’s Interim Environmental Utilities Director Brian Wheeler.

Ice pigging consists of two trucks set up on opposite sides of a neighborhood and run by a specialized crew, one of only a few crews in the world that offer the process.

The first truck, a large tanker filled with about 2,700 gallons of an ice-salt mixture hooks up to a fire hydrant on one end of a length of underground water pipe.

The ice pigging truck pumping 2,700 gallons of ice-salt mixture into the city's water pipes.

City crews close off surrounding pipes to isolate that length and then the truck begins pumping the icy mixture into the system.

Wheeler said it’s kind of like a giant Slurpee drink that forms up into a plug of ice in the pipe.

Then, when crews start flowing water in, he said it acts in the same way a glacier would: Scraping the built-up sediment and contaminants in the pipe and forcing it all out of a hydrant hooked to the truck on the other end of the neighborhood.

For St. Cloud leaders and residents, getting that mess out of the city’s pipes is a major priority.

For several years, residents have reported incidents of reddish-brown, murky water flowing from the faucets in their homes.

In recent months, the problems appear to have grown more widespread, as neighbors have flooded public meetings demanding solutions.

Wheeler said a leak was discovered in one of the city’s water treatment plants that had been releasing small amounts of a treatment resin into the water supply for years.

The result was the discolored water.

While the issue has been fixed and water is now running clear out of the plant, city leaders have struggled to get all of the resin out of their underground water pipes and brown water has continued popping up at homes across the city.

So, Wheeler said they’re trying the ice pigging on sections of the city’s pipes to see if it clears up those contaminants.

Samples taken during the ice pigging process showing the water going from murky to clear as the pipes clear out.

So far, he said the results are promising.

"The clear water follows the ice as the ice comes out and that's what we like to see,” Wheeler said.

He said many residents in the already "pigged" neighborhoods are reporting clear water in their homes.

However, the process is slow and expensive.

The city council has already authorized an extension to St. Cloud’s deal with the ice pigging contractor so they can complete cleaning more of the system.

However, Wheeler said the company is in high demand and they won’t be able to rely on the process alone.

Brown water pouring from the back end of the ice pigging process.

"This isn't, we're nowhere near the end, unfortunately,” he said.

Wheeler said they’re exploring other options to complement the ice pigging.

Last week, city council members asked city staff to get estimates on installing whole-home water filtration systems on all houses in town affected by the water problems.

No word yet on if they plan to pursue that option.

At last check, the ice pigging is scheduled to continue through April.