Chicago based companies Urban Canopy and Growing Power give a tour of their compost processes.

Once a week, Alex Poltorak roams the alleyways of Chicago's Andersonville neighborhood hunting for white buckets stashed here and there crammed with banana peels, avocado shells, bits of onions and other colorful vegetable scraps from his customers' kitchens.

In turn, Poltorak deposits at his stops a fresh six-gallon bucket with beige flakes. He gets the chaff from a local coffee roaster. "It helps with the compost smell," he explained.

Formed in November, the Andersonville Community Compost program has attracted some 70 residents who pay $5 per week for Poltorak to pick up their scraps. He hauls the kitchen refuse in his beat-up delivery van to an urban farm in Englewood, a practice that is legal at the state level but illegal under a city ordinance that proponents of urban agriculture are pressing to change.

Since Chicago streamlined zoning laws in 2011 to support urban agriculture, the number of urban farms has grown to 11 from two that year. And as the number of city-backed community gardens has grown to 44, so, too, has the demand for compost and businesses that haul food waste.

But city regulations governing composting haven't kept up with the interest in urban farming or gardening in the city. Some Chicago gardeners simply don't have the space to do their own composting.

"This is ideal for us," said neighborhood resident Lee Herman, 62, of the Andersonville program, run by the Andersonville Development Corp., a local nonprofit. "We are in the city and have a pretty small yard, so there is really not space for a compost pile."

Some suburbs have launched composting programs with mixed results. Last year, Highland Park put on hold its curbside program after a commercial composting facility stopped accepting food scraps. The facility was cited twice by the Lake County Health Department with permit violations relating to odors and operational issues, said Michael Kuhn, the department's solid waste unit coordinator.

In August, state lawmakers amended the Illinois Environmental Protection Act to allow urban farms to accept donations of composting additives such as wood chips or food scraps, a practice that many Chicago farmers were already quietly implementing.

The new rules waive a permit for farmers who dedicate up to 2 percent of their land to composting as long as the fertilizer is not sold, fees are not charged for accepting waste and the compost operation registers with the Illinois Environmental Protection Agency.

Though it is legal to haul food scraps to commercial composting facilities, Chicago law only allows farms and community gardens to compost materials generated on site and kept in a container. Permits are needed for containers larger than 5 cubic yards, about the size of a garden shed. Gardeners can also compost landscape waste, but the city requires a permit if the compost pile exceeds 10 cubic yards.

Urban farmers say those limits are too stringent. Iron Street Urban Farm in Chicago's Bridgeport neighborhood said it needs three to five tons of food scraps a week to grow the fruits and vegetables it sells at farmers markets and drugstores throughout the city.

To meet city requirements to process that much vegetable waste, Iron Street essentially had to fill out permits as if it were opening a landfill, said Lauralyn Clawson, youth program coordinator at Growing Power Chicago, the nonprofit that runs Iron Street.

The permit process included providing documents signed off by engineers and environmental experts, an effort that many upstart gardeners and composters wouldn't have been able to afford. Growing Power spent more than $20,000 to get its permit, which it paid for with a grant, Clawson said.

Among the groups pushing the city to bring its regulations in line with the state are the Chicago Food Policy Advisory Council, a nonprofit that advocates for responsible food and agricultural policy, and the Illinois Environmental Council, an advocacy group representing 50 environmental groups.

Jennifer Walling, executive director of the Illinois Environmental Council, said a new ordinance is expected to be submitted to Chicago's City Council "within the next couple of months." Walling said the city looked into amending its compost law when zoning laws were updated in 2011 but waited until state law was first amended.

"We are trying to be as cautious as possible with the laws to avoid problems that can impact the entire industry and get to a point where nothing is allowed," Walling said. "We want as many compost sites as possible, but we want them appropriately overseen to prevent any bad actors."

There are reasons for concern. The state has shut down various composting facilities since it banned yard waste from landfills in 1990. At least one was sued by the state's attorney general for allegedly processing and accepting waste with a permit that had expired.

Peter Strazzabosco, Chicago deputy development commissioner, said the city has had initial discussions about the basic issues of composting.

"I would add that the city would continue to support the expansion of urban ag and entertain ideas that could further promote its viability in Chicago," he said.

A lot of city soil is contaminated, especially in industrial areas where many urban farms have located, so farmers take precautions. To protect its vegetables from Chicago soil, the Iron Street Urban Farm places rows of fertilizer atop a bed of wood chips 2 feet deep that sits on top of concrete.