Increasingly popular bathroom wipes — pre-moistened towelettes that are often advertised as flushable — are being blamed for creating clogs and backups in sewer systems around the nation.

Wastewater authorities say wipes may go down the toilet, but even many labeled flushable aren’t breaking down as they course through the sewer system. That’s costing some municipalities millions of dollars to dispatch crews to unclog pipes and pumps and to replace and upgrade machinery.

The problem got so bad in this western New York community this summer that sewer officials set up traps — basket strainers in sections of pipe leading to an oft-clogged pump — to figure out which households the wipes were coming from. They mailed letters and then pleaded in person for residents to stop flushing them.

“We could walk right up, knock on the door and say, ‘Listen, this problem is coming right from your house,’” said Tom Walsh, senior project coordinator at South & Center Chautauqua Lake Sewer Districts, which was dispatching crews at least once a week to clear a grinder pump that would seize up trying to shred the fibrous wipes.

The National Association of Clean Water Agencies, which represents 300 wastewater agencies, says it has been hearing complaints about wipes from sewer systems big and small for about four years.

That roughly coincides with the ramped-up marketing of the “flushable cleansing cloths” as a cleaner, fresher option than dry toilet paper alone. A trade group says wipes are a $6 billion-a-year industry, with sales increasing nearly 5 percent a year since 2007 and expected to grow at a rate of 6 percent annually for the next five years.

Manufacturers insist wipes labeled flushable aren’t the problem, pointing instead to baby and other cleaning wipes marked as nonflushable that are often being used by adults.

“My team regularly goes sewer diving” to analyze what’s causing problems, said Trina McCormick, a senior manager at Kimberly-Clark Corp., maker of Cottonelle. “We’ve seen the majority, 90 percent in fact, are items that are not supposed to be flushed, like paper towels, feminine products or baby wipes.”

Wastewater officials agree that wipes, many of which are made from plastic, aren’t the only culprits but say their problems have escalated with the wipes market.

Vancouver, Wash., sewer officials say wipes labeled as flushable are a big part of a problem that has caused that city to spend more than $1 million in the past five years replacing three large sewage pumps and eight smaller ones that were routinely clogging.

To prove their point, they dyed several kinds of wipes and sent them through the sewer for a mile to see how they would break up. They didn’t.

Those labeled flushable, engineer Frank Dick said, had “little rips and tears but still they were intact.”

The Washington Suburban Sanitary Commission, which serves Montgomery and Prince George’s counties in Maryland, has also spent more than $1 million over five years installing heavy-duty grinders, while the Orange County, Calif., Sanitation District, in a single year recorded 971 “de-ragging” maintenance calls on 10 pump stations at a cost of $320,000.

Clogging problems in Waukesha, Wis., prompted the sewer authority there to create a “Keep Wipes out of Pipes” flier. And Ocean City, Md., and Sitka, Alaska, are among cities that have also publicly asked residents not to flush wipes, regardless of whether they are labeled flushable.

The problem got worldwide attention in July when London sewer officials reported removing a 15-ton “bus-sized lump” of wrongly flushed grease and wet wipes, dubbed the “fatberg.”