CHARLESTON, W.Va. -- Grease and wet wipes. It's the stuff "fatbergs" are made of. Charleston's sewer lines may not house anomalies such as London's 15-ton mass of fat found in the city's drains last spring, but workers at the Charleston Sanitary Board frequently encounter their own versions, said Operations Manager Tim Haapala. Wet wipes, thought to be flushable, cause real problems for municipal sewer pipelines. These wipes, when paired with grease that gets into drains, can create masses in the city's pipelines that can be costly to remove, Haapala said. Any number of items can cause blockages, but the wipes are one of the biggest culprits for back ups, Haapala said. "They're not degradable. That's the problem," Haapala said. These wipes can't be pushed down sewerage lines, especially by newer toilets, which only provide about a 3-gallon flush. Older toilets, Haapala said, were 5-gallon flushes. Old pipelines made of clay don't help the situation. "When you put those types of things down the drain in an old line and don't put the volume of water behind it to flush it, you're not flushing it," Haapala said. "It's just staying behind." Wipes will sit in sewer lines and catch the grease that's passing by. "That grease mixes with the towels, the wipes and then congeals," Haapala said. "It slowly builds ... like cholesterol in a vein." Of the 300 miles of pipeline maintained by the board, blockage issues tend to be worse on the West Side, East End and in Kanawha City, said Larry Roller, sanitary board general manager. "We run into these problems primarily on the flats ... because the lines are flatter, less slope," Roller said. While the sanitary board offices are open from 9 a.m. to 5 p.m., Haapala said maintenance crews are on call 24-7. The process for solving a blockage issue can require a multitude of workers, from pipeline camera operators to those manning the vacuum trucks that flush pipelines and remove refuse. A four-hour blockage removal can easily cost the city $1,500, Haapala said. The cost of these calls is reflected in the rates, Haapala said. Roller added that these issues could affect homeowners even more directly via backups and flooding. "The incentive is on the property owner not to put those things in the line, because you flood yourself," Roller said. The Sanitary Board has spent time doing outreach, Roller said. With every blockage visit, maintenance workers will go over with a customer what caused the issue and how to prevent it. The board also sends a copy of the city's sewerage ordinance with its bills. It's also posted online, Roller said. Roller and Haapala said the city has slowly been replacing the old, clay pipelines with plastic ones as it has become necessary. But the cost of replacing the entire system is high and might not do much to help the situation. "Newer materials would help, but the bottom line is that stuff shouldn't go in the toilet to begin with," Haapala said. Reach Rachel Molenda at firstname.lastname@example.org or 304-348-5102.