As communities around Philadelphia identify new ways to reduce their carbon footprint and minimize waste, their efforts are undermined by households unwittingly producing “fatbergs” by pouring things like turkey grease down the drain.

Caused by the accumulation of oil, grease, and non-disposable waste dumped down toilets and sinks, these disgusting masses grow over months and even years. The result? Sewers are clogged, wastewater infrastructure is damaged, and public and private sewer backups cost vital tax dollars. And beyond the associated clean-up costs, fatbergs present a tremendous environmental and public health threat.

Many sewer spills are caused by fats, oils, and grease. Not only is this problem contributing to inflated operating costs for cities and towns, but fatbergs can become so bloated they cause people’s toilets to back up, flooding their homes with raw sewage.

The U.S. spends millions annually addressing fatberg issues in cities big and small. Such clean-up costs exceeded $18 million last year in New York alone. In 2017, Baltimore spent about $60,000 clearing a single 20-foot fatberg. Detroit cleared a massive 100-foot-long fatberg found in an 11-foot diameter pipe, costing the taxpayers $100,000.

This is a global issue, impacting both urban and rural communities. Even in smaller cities and towns, these annual costs can climb into tens of thousands of dollars. For instance, Fort Wayne, Indiana has spent half a million dollars a year cleaning grease out of sewers. One particularly appalling mass — the size of a double-checker bus — was recently found in a drain in London.

In Rialto, Calif., where I work as the general manager of the city’s water and wastewater treatment plants, recently experienced a fatberg-induced backup, causing overflowing sewage at two busy intersections. My colleagues at Veolia North America — which specializes in managing wastewater treatment for municipalities across the country — worked with local officials, spending the better part of a week using heavy equipment to flush and vacuum the sewer overflows that covered streets and spilled into nearby stormwater catch basins.

Communities across Greater Philadelphia and beyond also face this growing threat. The solution begins at home. Many products, such as wipes, are marketed as “disposable,” so people flush them down the toilet not realizing the consequences. The reality is they frequently attach themselves to grease and oil residing in sewer pipes, allowing fatbergs to snowball and leading to overflows, backups, clogged pumps, and failed sewer systems.

Restaurants tend to be the biggest culprits of disposing grease improperly, but average Americans should be mindful of the best way to properly dispose of their household items.

Whether it’s securing grease in a sealed non-recyclable container and throwing out with regular garbage, or simply being careful to not use the sink as a toilet — or the toilet as a garbage disposal — there’s a lot everyday people can do to minimize the dangers of fatbergs.

And with the holiday season underway, it’s particularly important to think twice before depositing turkey grease down the sink. Hot fat can be poured easily, but quickly solidifies, causing sewer pipe blockages. Small pipes in homes are most likely to be affected, risking blocked drains, flooding and, eventually, increased pollution.

In the United States, over 14,000 wastewater treatment plants support vital infrastructure systems protecting public health and the environment. According to a recent infrastructure report card, at least $271 billion of investment is needed to meet current and future wastewater system demand. While there’s a huge scope at play, this issue is ultimately local and personal.

Given the financial and environmental impact on municipal sewers, along with residential plumbing, this is a critical moment for Delaware Valley residents to step up on addressing flushable waste and grease traps. The negative image of fatbergs — disgusting, oozing blobs — is well earned. Now it’s time that their serious, expensive and long-term repercussions on public health and the environment are met with similar revulsion.

Aaron Kraft is a General Manager at Veolia North America, which operates plants in the Delaware Valley region.