MILWAUKEE - Part-time waitress, full-time garbage entrepreneur — Melissa Tashjian has carved out a niche helping turn smelly food scraps into a dark, rich medium to grow more fruits and vegetables.

Two years ago, Tashjian started her little business, Compost Crusader LLC, with a small, slow-moving dump truck and a handful of ­customers.

Today, the Milwaukee resident's client list of restaurants, schools and hospitals stands at 55 and is growing by the week. Her original truck, "Torty," has been traded in, replaced by two larger garbage trucks.

In April, Tashjian's outfit picked up 115,000 pounds of food waste and other organic material — more than four times the weight she was handling in the summer of 2014.

And, she's making money. Not much, but enough that she has reduced her waitressing hours and stopped driving her trucks in favor of calling on potential new accounts.

"I think that in one year from now I'll have at least a hundred customers," Tashjian said. " … I want to just keep growing and spreading the message because it makes sense and so many other states and ­cities are doing it successfully."

There's lots of room to grow. Americans dump 70 billion tons of food waste into the garbage, the Environmental Protection Agency estimates. It's the largest single component going into municipal landfills.

But recycling of food scraps is on the rise. More than 200 communities offered curbside food pickup in 2013, said a 2015 EPA report. And firms such as Tashjian's, which pick up food scraps at businesses, homes or both, have sprouted in dozens of cities.

Jeremy Brosowsky said there simply weren't any other collectors when he started Compost Cab in Washington, D.C., in 2010. "Now I think there are 40 or 50 companies doing it around the country in one form or the other, including a few here in Washington," he said.

And Tashjian isn't the only one growing.

Philadelphia's Bennett Compost has gone from about 1,000 residential customers less than two years ago to 1,400 today. During the same period, Bootstrap Compost, in Boston, has seen its residential accounts grow from 750 to 1,500, and its business customer base rise from 50 to 85. Rust Belt Riders Composting, in Cleveland, which started about when Tashjian did, now has 45 clients and is adding about two per week.

Ecological concerns generate part of that interest, and help motivate some of the folks launching collection businesses. When it started, Bootstrap Compost hauled by bicycle. So did Rust Belt Riders. In Chicago, Jonathan Scheffel still does.

He pedals more than 500 miles a month through the city, collecting waste from 160 homes and 10 businesses, and hauling it — as much as 400 pounds per load on an 80-pound bike trailer — to a worm farm in the Back of the Yards neighborhood on ­Chicago's South Side.

Not yet a year old, his business, Healthy Soil Compost, is one of six food-waste collectors now operating in the city, he said. Others use motor vehicles, but Scheffel, 28, has stuck with two wheels.

"A lot of people sign up with me because I'm bicycle powered, and the value of that is pretty high, I think," he said.

Green values also help drive demand for such services.

Tashjian said many of her customers are able to reduce their regular trash pickup enough to cover the cost of separate collection of food scraps and other organic waste.

It's pretty close — perhaps 90 percent covered, said Kristin Hueneke, executive chef at Milwaukee's Lakefront Brewery. "But where we really make up is the peace of mind with it, that we know this isn't all going to a landfill," she said.

Milwaukee restaurant owner Wendy Mireles said using Compost Crusader at her two restaurants increases her overall waste disposal bill — by a few hundred dollars in March, for example. But Mireles, who not only separates her garbage but pays extra to buy paper and plastic products that can be composted, also has a philosophical commitment to reducing her restaurants' eco footprint.

Mireles applauded Tashjian's efforts, as did good-food guru Will Allen. Allen's Milwaukee nonprofit, Growing Power, collects millions of pounds of food waste annually to help make compost for its roughly 300 acres of farmland. But he welcomes the far-smaller bite Tashjian is taking out of the Milwaukee area's mountain of garbage.

Compost Crusader hauls its scraps to Blue Ribbon Organics, a compost farm that receives an average of 100,000 pounds of food waste a week.

Most of that comes from much larger collector Sanimax, a Montreal-based company with extensive U.S. operations. But Tashjian's contribution is rising, helping to enrich the area's supply of soil-enriching compost, and replacing stinky odors with good ones. "It smells like wet earth," Tashjian said of the finished product. "You know, it smells like after a spring day."