Thanksgiving is a royal pain in the U.S. drain.
Thanksgiving means turkey dinners, family gatherings and football. For household drains and aging sewers across the United States, it means a lot of grease going down the pipes - and into the sewers.
For some harried cooks, the simplest way to get rid of fat from turkeys, bacon and roasts is down the kitchen drain. There it congeals, clogging the pipe and trapping food scraps until the only solution is to call the plumber.
"The day after Thanksgiving is the perfect storm for us," said Paul Abrams, a spokesman for Roto Rooter, the biggest U.S. plumbing and drain cleaning service. "We have all hands on deck."
The number of calls to the company's 7,000 plumbers and drain experts that day jumps 50 percent over a normal Friday. Calls go up by a fifth over the four-day Thanksgiving weekend, Abrams said.
Thanksgiving is especially stressful for household drains.
Cooks, sometimes inexperienced, overload garbage disposals with potato peelings, pumpkin pulp and other food waste. They fail to use enough water to flush them down the pipes, then put cooking grease and oil in the mix.
"Before you know it, they've sent a large slug of semi-solid material down, and it just stops," said Chuck White, vice president of technical services at the Plumbing Heating Cooling Contractors Association, an industry group.
Congealed grease can harden into a consistency like candle wax or clay. Stringy pumpkin pulp takes on an epoxy-like hardness when dry.
Household heart attack
When houses are packed with guests, there are more showers and toilet flushes than normal. People chuck disposable wipes, cotton balls or hair down the toilet.
"Your house kind of has a heart attack," Abrams said. "All that extra activity is enough to push it over the edge."
Some of that household oil and fat makes its way into the 600,000 miles of aging U.S. sewers.
The U.S. Environmental Protection Agency reported in 2004 that grease is the No. 1 cause of blocked sewers, at 47 percent of stoppages. In New York, the nation's biggest city, grease causes 62 percent of blockages, according to a 2013 report by the city's environmental department.
Blockages cause sewers to overflow. The EPA report said that there were between 23,000 and 75,000 U.S. sanitary sewer overflows a year, discharging up to 10 billion gallons (38 billion liters) of raw sewage.
Adam Krantz, managing director for government and public affairs at the National Association of Clean Water Agencies, put the price tag for clearing blockages at hundreds of millions of dollars a year.
Grease is "a very big issue," he said.
The problem has worsened in the last 25 years, he said, as the U.S. population grows and sewer systems, some with pipes 100 to 200 years old, become more fragile.
To avoid home drain problems, experts have some advice:
- Clean up oil and grease with paper towels and discard them. Or pour off the grease into a container, let it congeal, and discard the container in the trash.
- Avoid putting stringy or fibrous waste down the disposal.
- Do not wait until the disposal is full to turn it on. Use plenty of water, and let it run for 20 or 30 seconds until it is clear.
- If there are a lot of house guests, wait 10 minutes or so between showers so slow drains can clear.
- Do not flush wipes, cotton swabs or paper towels down the toilet.
- Take care of plumbing problems before the holidays.