Adapting to the Nonwoven Wipes Problem

Collection Systems, Technology and Innovation, Wastewater News

This story was originally posted on the Woodard & Curran blog.  CWEA’s coverage of wipes issues is supported by Aqualitec

Those of us who have witnessed the destruction non-woven wipes are having on our pipes and pumps understand the impact a simple word like ‘flushable’ can have. Since the mid-2000’s, the wastewater industry has been battling with the increasing prevalence of disposable nonwoven wipes in our sewer systems. While some progress is being made on both the legal and regulatory fronts, utilities are predominately left trying to deal with the day-to-day reality of “life after wipes.” As the industry works to simultaneously stop flushable wipes from entering pipes and minimize the impact they are having on our operations, sharing success stories with each other can help solve this persistent problem.

Following the replacement of their major wastewater pump stations in the mid-2000’s, The Town of Billerica. MA began experiencing clogging issues daily. The town spent years trying all manner of homemade solutions, but the problem persisted. Through an outreach campaign, equipment upgrades, and a bit of trial and error, we found Billerica a solution that protected their infrastructure from equipment clogging due to wipes.

A perfect storm: efficient pumps meet ‘efficient’ wipes

As Billerica rehabilitated its major wastewater pump stations during the mid-2000’s, they were installing more energy-efficient pumps just as nonwoven wipes usage was increasing. During this time, pump stations were outfitted with typical non-clog pumps that historically have been the workhorses of the industry. Yet, these pumps immediately proved to be no match for the quantity and type of material now being routinely introduced into the sewer system.

At that moment in time, very little was known about these nonwoven wipes. It was assumed that the pump manufacturers were somehow at fault due to changes in their design or some other change in their product. As it became clear that nonwoven wipes were an industry issue and not something unique to Billerica, the town began taking proactive steps to protect their system and decrease the amount of maintenance required by the clogging pumps.

New problem calls for new technology

First, the town tried to solve the problem by installing channel grinders on the two largest stations that were experiencing the most clogging issues.  The grinders were the traditional coil drum channel grinders and they proved to be inadequate almost immediately.  These grinders, while excellent at processing bricks, wood, and other large debris, were easily blinded by the wipes and became clogged.  This would allow the wipes to bypass the grinder and end up right back in the wetwell, clogging the pumps. Thankfully, just as the town was realizing that these issues were not going away anytime soon, so were the grinder and pump industry.

The grinder manufacturers quickly came up with a new channel grinder design that was specifically targeted toward macerating wipes.  The channel grinders in Billerica were replaced with the new style perforate plate channel grinders that have solved the clogging issue.  In addition, typical non-clog pumps have been supplemented with chopper pumps to provide an added degree of reliability.

Public outreach supports technical solution

Once the town realized that the wipes problem was a new phenomenon, they also began a public outreach campaign to try and curb the introduction of wipes into the sewer system.  The campaign consisted of town website postings and material as well as mailers in the quarterly water bills to residents.  While it is unclear whether the town’s efforts or the industry’s efforts at large are having any effect on the quantity of non-woven wipes entering the sewer system, the most direct way to solve a problem like flushable wipes is by communicating with your customers.

While it may not lead to great dinner table conversation, every municipality with a public sewer system should be concerned about the prevalence of nonwoven wipes. INDA, an association that represents the nonwoven industry, is working to establish more stringent rules regarding flushability, but in the meantime, we should all do our part by continuing outreach efforts and sharing strategies that have helped reduce the impact of non-woven wipes on our systems.

View the original story on Woodard & Curran’s blog