Sewage was seeping into a resident's basement, and Dan Kovar could guess the cause: wet wipes.

Across the country, public works directors like Kovar are extracting the disposable baby, facial and disinfecting wipes that have gotten caught in key pieces of their plumbing networks. The cloths have increasingly plugged pipes and pumps in recent years, forcing Minnesota cities to boost their monitoring and invest in expensive grinders.

The flooded basement in Wadena, Minn., led workers to the latest blockage, a dirty mass largely comprised of wipes that would not break down. "They come out just like they go in," Kovar said, "in one piece." In March, he posted a warning to the city's Facebook page: A wipe labeled "flushable," he explained, only means that it "will fit down the piping within your home."

Down the line, it's another story. The wipes combine with grease and paper, forming massive clumps wastewater folks have nicknamed polar bears. They eventually wind around pumps at lift stations, which bring sewage and wastewater to higher elevations, testing their motors and gears.

"It's a huge problem — an absolutely horrible problem," said Frank Stuemke, of the Minnesota Rural Water Association. Wipes have shortened pumps' lives and transformed what it means to maintain a system, he said. "To smaller communities, in particular, it can be difficult."

A spokesman for the growing industry that makes moist wipes pins the blame on people improperly flushing items that were never meant to go down the toilet, such as baby wipes. "Flushable" wipes, made of organic fibers, make up just 5 percent of the market, said Dave Rousse, president of the Association of Nonwoven Fabrics Industry, a trade group representing manufacturers of wipes and other products.

"We acknowledge that they're having a problem," Rousse said. "But they're blaming the wrong item for their problem."

The group has designed a do-not-flush logo for companies to put on their packaging and has been working with wastewater organizations on a new version of voluntary standards to define "flushable."

Some city officials have argued that even "flushable" wipes don't break down. They also say the guidelines don't get at a problem they're seeing: Wipes "reweaving" within their pipes.

On Friday morning, workers in Avon, Minn., pulled up two wastewater pumps from 15 and 25 feet underground. Then they removed, with gloved hands and tools, gobs of wet rags.

Utilities Supervisor Jon Forsell and his team monitor these pumps daily, removing wipes weekly. "Unfortunately, we have to do it all the time," he said. They're educating residents, folding pamphlets into water bills. They're also upgrading their equipment: At Monday night's City Council meeting, Forsell will request $17,000 to replace a pump with a better brand.

"That's a great expense for a smaller city like this," he said.

But big cities, too, have highlighted equipment strains and swelling budgets. New York City officials reported the city spent more than $18 million over five years on equipment problems caused by wipes, according to Bloomberg News.

In Minnesota, the Metropolitan Council collects and treats about 250 million gallons of wastewater in the metropolitan area each day. The council's environmental services division spends staff time unclogging equipment and filtering screens, spokesman Tim O'Donnell said by e-mail. It supports national efforts to improve labels and educate consumers, he said.

While some Minnesota cities have found that pamphlets and videos have helped, others say the problem is still picking up. In Edina last year, 13 of 15 sewer blockages involved rags and wipes, said David Goergen, Public Works coordinator.

"It's getting worse," said Scott Gilbertson, Detroit Lakes' wastewater supervisor, of the more widespread use. "We're just constantly fighting it."

Nursing homes, hospitals and group homes seem to be a big source of wipes, Gilbertson said. His workers are now finding more large towels and disposable rags downstream from commercial districts with restaurants and stores such as Wal-Mart. "It's hard to change the ways of larger institutions," he said.

Gilbertson won't use wipes in his own home.

People don't consider what follows a flush, he said. "Until they have a problem or they don't have water, they don't think about it."

Jenna Ross • 612-673-7168