“Offering a washer and dryer in-unit is a trend we’re certainly seeing,” says Paula Munger, the director of industry research for the National Apartment Association. A recent survey by the industry group found the addition of washers and dryers to be one of the most common upgrades to apartments in recent years. ... That has posed a problem for laundromats. According to data from the Census Bureau, the number of laundry facilities in the U.S. has declined by almost 20 percent since 2005, with especially precipitous drops in metropolitan areas such as Los Angeles (17 percent) and Chicago (23 percent). (While that data includes both laundromats and dry cleaners, laundromats account for the bulk of the drop.) In the disappearance of laundromats, a longtime staple of urban living, one can detect yet another way that cities have changed in response to an influx of higher-earning residents. ... Collectively earning $5 billion each year, as estimated by the Coin Laundry Association, the U.S.’s coin-operated laundromats are overwhelmingly mom-and-pop operations and share a tightly knit history with the American city. ... Laundromats’ margins are further thinning as the price of water and sewage services have risen across the country.