It’s now up to officials in Houston to decide who will lead the city’s proposed “one bin for all” recycling program.

The city recently closed a request for proposals period and received five bids from firms looking to take the helm of the program, which will allow residents in America’s fourth-most-populous city to put recyclables, trash and organics in a single curbside cart.

Once collected, material will be separated at a yet-to-be-built materials recovery facility, or “dirty MRF”, and at least 75 percent of the collected refuse will need to be recycled, composted or converted into energy.

City officials say they will review the proposals and submit recommendations by the end of this year.

Proponents of the plan argue the approach will finally jump-start diversion in Houston, which has a 6 percent recycling rate through its current curbside collection program. “We have reached another key milestone in this process and are eager to move forward as this advanced recycling and waste diversion technology has the potential to improve health and quality of life not only in Houston, but around the world,” Annise Parker, Houston’s mayor, said in a press release last week.

Opponents, including the Natural Resources Defense Council, charge that dirty MRFs have never been able to recover sufficient or cleanly material.

“From the perspective of materials management, from the perspective of recovering recyclables in an optimal way for purposes of marketing, this is not the best way to go,” Allen Hershkowitz, director of the solid waste program at the Natural Resources Defense Council, told the Texas Tribune.

The argument over whether to employ mixed-waste-sorting MRFs has recently taken place in other large municipalities as well. Last month, Indianapolis’ mayor, Greg Ballard, opted to accept a proposal for a hotly debated $35 million facility from waste-to-energy firm Covanta. Montgomery, Alabama, also recently opened a similar mixed-waste sorting operation.