How to Solve the Flushable Wipes Problem at Your Plant

Solving the flushable wipes problem requires a two-pronged approach: It begins with public education and ends with proper equipment. Find out how manufacturers are approaching the wipes dilemma.
How to Solve the Flushable Wipes Problem at Your Plant

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Handy at home, trouble at the treatment plant.

They’re flushable and disposable wipes. Despite recent cooperation between the wastewater profession and the INDA (Association of Non-Woven Fabrics Industry), they’re causing clogging problems in sewer systems and wastewater treatment facilities coast to coast.

According to Rob Villee of the Plainfield (New Jersy) Area Regional Sewer Authority, the Water Environment Federation and INDA are drafting a flushability guidance document and are developing a stewardship process with corporate sustainability personnel to lessen the affect of nonflushable wipes (baby wipes) that are getting flushed.

“On the good news side, we are seeing lots of new flushable substrates come on the market,” says Villee, who has won awards for his work on the problem. “Some are really good — like Kimberly Clark — and some are better than toilet paper, like the wipes from Haso USA [currently marketed in Asia but planned for the U.S.]. Other manufacturers are improving their substrates, but their new ones still fall far short of where wastewater thinks they need to be.”

Wipes at Waukesha
Waukesha, Wisconsin, is trying internal and external approaches to keep flushables and disposables from creating problems. On the outside, they’ve sent notices and bill stuffers to customers in targeted neighborhoods and have publicized the problem in the public works newsletter. Inside, they’ve replaced the pump impeller on a lift station that was having trouble passing the material.

“It’s a widespread problem, affecting not only Waukesha but many other utilities,” says Jeff Haranda, manager of Waukesha’s 10 mgd treatment plant.

Tim Young, the utility’s pretreatment manager, says the mailings have had some effect, although it’s not easy to tell and the changes have not been dramatic.

“Where we have a dedicated sewer line from a specific facility — like a health care center — we can monitor the amount of flushables coming into the system and go out and talk to them about the problem,” he says.

The lift station pump impeller change-out appears to have had some effect, too, although Young says it’s also difficult to assess. He says his utility will know better come spring when the system flushes out.

Waukesha has analyzed the material clogging up the system.

“We dried them out and in most cases it’s a non-woven synthetic fiber material that’s very strong,” Young says. “When they get intertwined, they form massive clogs.”

The 3 Ps
San Francisco, California, has developed a catch phrase to keep flushable and disposable materials out of the sewer system.
It’s the three “Ps” explains Idil Bereket, of the San Francisco Public Utilities public outreach division.

“Pee, poop and paper [toilet paper] is all that should be flushed down the toilet. Nothing else goes in there,” she says, adding the phrase not only clarifies the problem but is catching on with some of the utility’s customers.

“When the material gets into our treatment plants,” Bereket says, “it gets tangled up in the screens. The plant has to stop the process, and operators have to remove the rags by hand. It takes time and takes people away from their assigned responsibilities.”

The 3-P message is hammered home during tours of the city’s Southeast and Oceanside treatment plants, which together treat about 80 mgd during dry weather.

“This is one of our main talking points,” Bereket says. “At the plant, people can see [the problem] with their own eyes.”

To the rescue
Equipment suppliers are coming to the rescue.

At the Vaughan Company, marketing manager Josh Niels says the firm has been working on chopper pumps, which combine the chopping and pumping mechanisms into a single process step, since 1960. Vaughan has supplied between 30,000 and 40,000 units.

The pumps are generally applied to the wastewater stream in lift stations or septic receiving stations, where they are capable of chopping virtually any disposable diaper or wipe material into smaller uniform pieces that can be pumped as a slurry down the line without clogging pipes and other equipment.

According to Niels, Vaughan chopper pumps are guaranteed to operate clog-free and are available in flow rates up to 13,000 gpm. Models range in horsepower from 5 to 250, with discharge connections from 3 to 16 inches in diameter. Vaughan’s proprietary mechanical seal requires no flush water to keep it cool, helping municipalities conserve water.

Niels agrees with others who say the terms disposable and flushable are relative.

“They might be disposable after a number of days [in the system],” he says, “but they don’t disintegrate fast enough to avoid clogging up the works.”

Double-barreled approach
JWC Environmental, supplier of the Muffin Monster line of grinders and Monster Separation systems, has performed numerous tests to determine what happens to disposable wipes in lift stations and treatment plants.

“We discovered that at about 10 percent of the installations, ‘wily wipes’ were getting around the screens,” says Alec Mackie, marketing manager. “They follow all holes, all routes. Even small pieces can rope together to wrap around shafts and clog screens.”

Fibers from wipes can also pass through screens, then ball up together to create ragging issues in aeration basins, heat exchangers, sludge pumps and other vital treatment plant process equipment, according to Mackie.

To address these issues, JWCE offers grinders and screens. Located at lift stations, the grinders are designed to ensure the capture of all items in the waste stream, including wipes, and drive the debris into the cutter stack. Wipes and other disposable materials are cut into small pieces to eliminate long strings that are likely to wrap together and form clogs.

The fine screens feature perforations of ¼-inch or less, and use brushless cleaning technology to remove debris from the panels and direct it into a JWCE washer compactor.

“The grinder and the screening system work together,” Mackie says, to help communities overcome the wipes problem and keep their treatment works clog-free.



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