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    Friday, May 17, 2024

    Wipes wreak havoc on wastewater plants

    Chris Riley points out materials floating in the Primary Settling Basin at the Norwich Wastewater Treatment Plant on Falls Avenue in the city Wednesday, May 4, 2016. (Sean D. Elliot/The Day)
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    A few years ago, workers at the New London wastewater treatment plant on Trumbull Street discovered a monster lurking in the system.

    During an inspection, Director of Public Utilities Joseph Lanzafame said, workers had found a few small holes in a screen that prevents solid objects — anything from paper towels to two-by-fours — from entering the plant.

    That triggered a look inside their sludge storage tank, where workers found a "rag ball" the size of a Volkswagen Bug made of congealed grease, cotton and disposable wipes.

    "It was mind-boggling to accumulate something that big," Lanzafame said.

    New London isn't the only system facing this problem. From Norwich to Stonington to Ledyard, in big wastewater systems and small, wipes being marketed as disposable are causing clogs everywhere: from the pipes transporting sewage to the plants themselves.

    For utilities, the only recourse is educating the public until regulations change.

    A recent trend

    Flushable wipes, a toilet paper substitute made by brands like Cottonelle and Charmin, are a new and popular innovation on the market.

    Their status as "flushable" is up for some debate, however.

    "From the experiments that we've done, (there's) one wipe on the market that we think might be flushable," said Cynthia Finley, director of regulatory affairs at the National Association of Clean Water Agencies.

    Discussions with the companies are ongoing and NACWA said they were not ready to release the name of that product.

    Her organization has been keeping an eye on the disposable wipes phenomenon since complaints were first filed in 2008, and recently launched the "Toilets are Not Trashcans" campaign with the aim of educating the public about products that cause damage to the sewer system, including the wipes.

    "What we really don't want is a ban on wipes (being) called flushable," said Finley, because research has shown people instead will buy baby wipes — a plastic product that will cause just as much, if not more, damage.

    Instead they would like to see the public using "the right product, that is truly safe," she said.

    "Flushable" wipes are one of many wipe products that end up in the sewers, Finley said.

    Such products are often difficult to distinguish from one another once they get to the end of the system.

    A study done in Maine showed that wipes made up about half of the material that hadn't broke down in the sewer system, and flushable wipes made up around a third of that, in addition to feminine hygiene products and baby wipes.

    The wipes combine with fats, oils and grease to create solid masses like London's infamous 15-ton "Fatberg," as it was christened by sewer company Thames Water. The mass caused damage to the system that took six weeks to repair.

    Norwich, Ledyard face a similar problem

    The headworks of a wastewater treatment plant is the first stage of the treatment process.

    In Norwich, which sees four million gallons on an average day, incoming sewage is piped in a deep, narrow channel through a small building.

    This houses the first few pieces of equipment: a screen that separates and lifts solids (such as wipes) upward out of the stream and into a conveyor, which rotates and transports the solids into a dumpster.

    The remaining sewage flows into primary clarification, where remaining solids settle and are removed.

    On Monday, in the tiny building housing Norwich's headworks, a few wipes had escaped the screen.

    A worker with a rake flicked a wipe off the pipe that transports solids to a digester, where bacteria break down biodegradable material.

    Some wipes were lying on the ground; they likely fell as workers were shovelling them out, said Mike LaLima, the wastewater integrity manager of ‎Norwich Public Utilities.

    In Ledyard, workers at the smaller Highlands Wastewater Treatment Facility on Town Farm Road occasionally will get a late-night call from the emergency dispatch center notifying them of a "breach of screen" alarm.

    The alarm means the screen has shut itself off, likely due to a clog of wipes. Workers have to drive to the plant and manually rake the wipes out of the system.

    "In this industry you can't sit back and kick your feet up: something like the wipes (will) come along," Supervisor Steve Maslin said.

    The National Association of Clean Water Agencies estimates nationwide that damage inflicted by wipes on wastewater systems is anywhere from $500 million to $1 billion — including replacing broken equipment, extra labor and power costs — much of which gets passed on to ratepayers.

    "Monster" help needed 

    Sewer treatment plants in the area are using machines called "Muffin Monsters" as their first line of defense against wipes.

    Muffin Monsters, made by JWC Environmental, a company that produces a wide variety of screening and shredding products for municipal treatment systems, are grinding pumps installed in places where sewage needs to be pumped upward to be sent to a wastewater treatment plant.

    In the Norwich Utilities building on South Golden Street, LaLima's calendar is adorned with JWC's wide variety of Monster products, such as the Auger Monster, a machine that grinds, screens and compacts waste solids, and the Honey Monster, a multi-stage machine that pre-treats material from pumped septic systems.

    As Kevin Bates, director of marketing at JWC explained, the original Muffin Monster was designed for 1970s sewage, which Bates said is fundamentally different from today's sewage.

    "We were designing to take the really tough solids, the rocks and sticks. We were never designing for indestructible pieces of plastic," he said.

    The company has since modified Muffin Monsters to grind material into smaller pieces, with less possibility for wipes to recombine and entangle in pipes.

    In New London, each of the of the six pump stations in the city is equipped with a Muffin Monster, but that's no guarantee there won't be clogs.

    For a while, clogged pumps were a weekly occurence, and it can be a race against the clock before sewage starts to back up into homes and businesses if the system isn't working.

    "The high flow times — spring rains — that tends to be the most frustrating times," Lanzafame said.

    Fortunately, sewage has not backed up into homes and businesses and clogs have become a less frequent headache, happening one or two times a month, said Lanzafame.

    That's thanks to the implementation of a program that reduces fats, oils and grease in the system by requiring restaurants to install grease traps and meet compliance checks.

    In Stonington, a similar program has helped Water Pollution Control Authority Director Douglas Nettleton cut down on the number of clogs, but wipes are still one of the biggest problems he faces.

    He likens the attitude toward flushable wipes to the attitude toward plastic and metal consumer products before the broad adoption of recycling.

    "You don't throw that aluminum can in the garbage," he said. "That's what I'm trying to get across."

    The Volkswagen Bug-ball of wipes took two or three workers several days to remove — piece by piece, five-gallon bucketful by five-gallon bucketful — until the clog was cleared.

    There has been no innovation on removing clogs — so far.

    The effort to educate the public has been small-scale so far. Norwich Utilities has mentioned its issues with disposable wipes in past versions of a newsletter, and Veolia Water has sent out a flier to New London customers along with their bill to educate them about the problems caused by wipes.

    Still, Lanzafame and other supervisors are optimistic that efforts to educate younger children in schools and during tours of the plant will make a difference in communicating the essential truth of the sewer system.

    "When you flush it, it doesn't just go away," Lanzafame said. "We certainly see it again."


    Water flows through a vertical raking screen at the Norwich Wastewater Treatment Plant on Falls Avenue in the city Wednesday, May 4, 2016. (Sean D. Elliot/The Day)
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