Don’t flush those wipes.

I know, it says “flushable wipes” on the package of numerous brands. You have Cottonelle Flushable Wipes, Babyganics flushable baby wipes and the bulk-purchase bargain, Costco’s Kirkland Signature Moist Flushable Wipes.

The problem is that they don’t break down, clogging pipes and pumps in Honolulu’s sewer system.

“I think people, on the whole, have no idea,” said Lori Kahikina, Honolulu’s director of environmental services. “They flush it, thinking it says flushable, out of sight, out of mind, and they don’t realize the impact it has on us downstream.”

As Kahikina describes it, there is a complex system of pipes that run from your bathroom along a 4-inch line to an underground main line in the street. Oahu’s 72 pump stations help move everything that goes down your toilet along to the treatment plant, sometimes for miles across the isle. From Hawaii Kai, for instance, it will need to travel to the Sand Island treatment plant.

Kahikina had no estimated cost for wipe-related problems, or for how many wipes clog the system every month because they clump together with a lot of other stuff that shouldn’t go down the drain, including dental floss, hair and paper towels.

But she confirmed that the problem has gotten worse in the past five years, prompting the city to launch a radio ad campaign this summer to educate the public about not flushing wipes.

Chronic clog-ups occur most frequently on the leeward side, at the Lualualei wastewater station as well as the West Beach station near Ko Olina. Kahikina says crews go to Lualualei at least once a week and to West Beach more than four times a week to pull clumps of wipes and other debris out of the pumps.

The Department of Environmental Services also asks the public not to flush other cloggers down the toilet, including disposable diapers, feminine hygiene products, paper towels, napkins, rags and dental floss. Sometimes unusual items turn up in the sewer system, including toys, clothes, car parts — even a bowling ball showed up once, according to Kahikina.

Besides the extra manpower expenses, Kahikina says pump replacements are costly. “A pump could last 15 years, but if it keep clogging, we have to replace it every two to three years,” she said.

It’s not just a problem in Honolulu. In New York in March, The New York Times reported more than $18 million had been spent over five years fixing equipment problems. In the United Kingdom the wipes are making their way from the bathroom to the beach through sewer system discharge. Volunteers at the “Great British Beach Clean” in 2014 picked up a growing number of wipes, according to the Marine Conservation Society.

When she used to visit elementary schools, Kahikina says she used to tell kids, “The only thing that goes in the sewers is No. 1, No. 2 and toilet paper, and that’s it. Nothing else.”

So please, don’t flush those wipes.

Nina Wu writes about environmental issues. Reach her at 529-4892 or nwu@staradvertiser.com.