We all know the real reason behind holiday family gatherings: food. The turkey, your mother’s special mashed potatoes and dressing recipes, the sweet potato pies and other desserts are the real stars of the season.
But leftover food and grease that doesn’t get scraped into the garbage often goes into the disposal or down the kitchen sink drain, flowing into the city sewer lines and collecting enough debris to cause blockages. And with colder temperatures, the grease solidifies more quickly, leading to potential sewer overflow.
Sewer overflow is preventable. That is the key message Houston Public Works wants the public to understand and why HPW launched its “Protect Our Pipes” campaign as a way raise awareness during the winter months.
“If we can work together to prevent fats, oils, grease and flushable wipes from entering our pipes, we can greatly reduce the number of sewer overflows in our community,” said Lacie Ulrich, event planning and outreach lead for Houston Water.
Ulrich said more than 70% of overflows in Houston are caused by clogs from grease and wipes. Overflows occur when a wastewater line becomes blocked and the untreated water cannot flow forward. When it has nowhere to go, the wastewater backs up and overflows out of manholes or cleanouts into streets, homes and environment.
The “Protect Our Pipes” campaign launched in the fall of 2020 and replaced HPW’s “Corral the Grease” campaign, which the department used since 2005. While it achieved modest success, Ulrich said HPW wanted a new campaign that was more inclusive, relevant, and provided a platform for wipes messaging as well as FOG (or fat, oil and grease) messaging.
During winter, HPW responds to nearly 20% more sewer overflows due to blockages caused by grease. Ulrich said fats and greases like the saturated fat found in foods such as meat, butter, milk, cheese, and palm oil solidifies at room temperature.
“It’s important to fully scrape off all leftover food waste directly into the trash to avoid FOG from entering our wastewater system,” she said.
Additionally, the city’s wastewater pipes are underground where the temperature is slightly lower than the above-ground temperature, making it easy for minor drops in temperature to cause grease to solidify and build up on the walls of pipes. That traps other items like hair and wipes and contributes to blockage, she said.
HPW is in the process of implementing an innovative program installing intelligent manhole monitors in locations throughout the city with a history of reoccurring overflows.
These intelligent monitors measure the level of wastewater in the manhole and send a notification when the wastewater level rises above pre-set levels, Ulrich said.
“This allows HPW to dispatch a crew to address the problem and prevent a sewer overflow from happening. So far, over 1,000 smart manhole monitors have already been installed,” she said.
Ulrich explained how the city’s wastewater system transports all the “dirty water” residences to a treatment plant where the water can be cleaned and discharged back into the bayou.
“When you wash your dishes in the sink, flush your toilet or take a bath, all of the dirty water leaves your home through a service lateral line and is transported together in one large city main line to one of the 39 City of Houston wastewater treatment plants,” she said.
“This means that any FOG that is rinsed off your pans, wipes that are flushed down the toilet, or hair that washes down the shower drain will meet in the city main lines and can combine to cause a blockage in the wastewater pipes.”
So, wait … flushable wipes also clog the lines?
“Flushable wipes are indeed ‘flushable’… but so are a handful of pennies,” Ulrich explained. “Wipes do not dissolve like toilet paper does, even if the packaging says ‘flushable’. Since they don’t break down at the same rate, wipes can easily get snagged in wastewater pipes or gather with grease to cause a blockage.”
Ulrich also said wipes remain intact through miles of wastewater lines all the way to the city’s treatment plants where they wreak havoc by clogging lift stations, pumps and blocking screens.
“To put it simply, wipes clog pipes,” she said. “All types of wipes should always be disposed of in the trash and never in the toilet.”
Ulrich said HPW responds to service requests from 311 calls and complaints within four hours. The inspector that arrives will investigate to determine the cause of the issue so the appropriate crew can respond.
If the inspector finds there is a blockage in the city line and an overflow is occurring, the stoppage team will be dispatched within 24 hours to clear the line and clean and disinfect the area.
“In 2022 alone, HPW responded to more than 20,000 service requests. For residents, that means if they call 311, an HPW inspector will be out to determine if the issue is a city issue and determine how the issue can be resolved,” Ulrich explained.
It’s an issue that is easily solvable, Ulrich said, by taking the following three steps: first, pour any leftover fats, oil and grease into a heat-resistant container like a can or glass jar. Next, let the FOG cool to a safe temperature. Finally, toss the full container into the trash.