Mobile Area Water and Sewer System crews are pulling a steady stream of grease, wipes and other debris out of the pipes and lift stations that keep the region’s sewage moving, and the utility says the cleanup is starting to carry a hefty price tag that ultimately lands on customers’ bills.
At the Eslava Creek lift station, one of dozens of pumping facilities that push wastewater through MAWSS’s network before it reaches treatment, workers recently pulled a sample from below the surface to show what has been building up inside the system. What looks from above like a routine holding pool for roughly 6 million gallons of sanitary sewer water is, just beneath the surface, choked with a thick mat of grease and debris.
“It looks like dirt, but it’s grease and debris,” said Terry Herman, a MAWSS lift station supervisor who oversees the Eslava Creek facility. Herman said the material has hardened into a mat six to eight inches thick sitting atop roughly 12 feet of wastewater, an accumulation that should not be there at all.
Pulled apart, the mat reveals a wide mix of items that never should have gone down a toilet or drain in the first place: grease, cotton balls, cotton swabs, condoms, toothbrushes, towels and a wide range of so-called flushable wipes. Herman said crews regularly find syringes, feminine hygiene products, hair, fishing line, plastic bottles, wash rags and shop towels tangled into the mass as well.
According to Herman, two culprits are doing most of the damage, and they make each other worse. Disposable wipes, even those marketed as flushable, do not break down the way toilet paper does. Once a wipe catches or snags on a seam or joint inside a pipe, grease poured down kitchen drains begins to cling to it, and the clump grows.
“When a disposable wipe is flushed and it catches or snags on the inside of a pipe, then fats and grease leach onto it, and then you have a perpetuating snowball effect,” Herman said.
That snowball effect is not just a maintenance headache, it is an expensive one. Crews already have to manually vacuum accumulated grease and debris out of lift stations like Eslava Creek twice a year, a labor-intensive process that pulls staff and equipment away from other system upkeep. MAWSS is now in the design phase of a larger fix: installing screening equipment at lift stations to catch rags and debris before they can build into the kind of mat crews found at Eslava Creek. Officials say that project, for just one station, is expected to cost about $1.5 million.
Herman said the bottom line is straightforward, and it is not good news for ratepayers. “The end result is it’s the customer that has to pay for maintenance of what we do,” he said. Every dollar spent vacuuming lift stations or engineering new filtration systems is a dollar that ultimately shows up in the rates MAWSS customers pay for sewer service.
To try to get ahead of the problem, MAWSS has launched a public education campaign called “It’s Easy to be Ungreasy,” encouraging households to stop pouring cooking grease and fats down sink drains. Customers can pick up a free grease collection container at participating distribution locations, fill it with used cooking oil and grease, and return it rather than sending the fats into the sewer system, where they combine with wipes and other debris to clog pipes and equipment.
Utility officials across the country have increasingly flagged wipes, even ones labeled “flushable,” as a leading cause of sewer blockages and costly equipment damage, a problem the wastewater industry has taken to calling a plumbing pandemic. MAWSS’s experience at Eslava Creek mirrors what other utilities have reported: wipes do not disintegrate in water the way toilet paper is designed to, and once snagged inside a pipe or pump, they become a magnet for grease and other debris moving through the system.
MAWSS officials say the message to customers is simple. Only human waste and toilet paper should go down a toilet, and cooking grease, fats and oils should be collected and disposed of separately rather than poured down a sink. Following those two rules, the utility says, would go a long way toward keeping pipes clear and holding down the maintenance costs that otherwise get passed along to customers across the Mobile area.