The biggest industrial polluters in Minneapolis have forged an alliance to reduce smog, improve emissions data and build trust with their inner-city neighbors under a new pilot project headed by the Minnesota Pollution Control Agency.

Designed as a nonconfrontational approach to regulate smokestack businesses that operate in tight confines with people, the Improving Minneapolis Air campaign is part of a broader effort to keep Minnesota in compliance with ever-tightening federal air standards. Particulates and lung-damaging ozone pollution are the most immediate categories of concern.

“The companies are in this voluntarily … but they were invited for a reason,” said Jeff Smith, director of the MPCA’s pollution control division. “They could have told us to pound sand, but none of them did.”

The “club,” as Smith sometimes refers to it, includes two molten metal foundries, a hot-mix asphalt plant, a manufacturer of residential shingles, a large metal plater, an Owens Corning roofing plant and the Hennepin County garbage incinerator next to Target Field. Smith said the 12 charter members are among the biggest stationary emitters of air pollution in Minneapolis or have the permitted capacity to be among the biggest.

The plan is for members of the group to conduct more stack testing and to expand disclosures about their internal operations. Smith said the extra information is critical to more precise modeling of local air quality, perhaps down to sections of a square mile or less. In turn, the transparency could alleviate health concerns among neighbors and lessen the neighborhood friction that delays pollution-control permitting for expansions or renewals.

Carl Michaud, Hennepin County’s director of environmental services, said the city needs a better breakdown of pollution sources to guide policy decisions. He said the current picture of ambient air quality — muddled as it is for individual neighborhoods — hurt the county in its recently failed bid for expanded garbage burning at the Hennepin Energy Resource Co. (HERC).

“We’ve got a pretty good sense of air quality, but it is not as detailed as people want it,” Smith said.

Rick Patraw, manager of community and business assistance for the MPCA, said the pilot project intends to avoid heavy-handed regulation, lengthy permitting fights and companies retreating into shells of litigation.

“It’s kind of a different model instead of going after a company and pounding on them,” Patraw said. “It’s helping to open up doors to have conversations.”

Besides benefiting from less confrontation, companies are eligible for technical assistance available through the program and for collaboration on image building.

At Smith Foundry Co., a longtime maker of metal castings for original equipment manufacturers, President Neil Ahlstrom said membership in the pilot project has aligned his company with the Minnesota Technical Assistance Program (MnTAP), a MPCA-supported cast of scientists and advanced-degree engineers at the University of Minnesota. A MnTAP team is now working to lower the foundry’s emissions of volatile organic compounds by converting the plant to a new set of degreasing agents.

“They know what technologies are state of the art,’’ said Joe Nelson, the foundry’s maintenance supervisor.

According to the MPCA, Smith Foundry is one of the lowest emitters in the pilot project. So, too, is Bituminous Roadways Inc., a loud and odorous hot-mix asphalt plant that operates next door to the foundry near the intersection of Cedar Avenue and E. 28th Street, less than a mile from downtown.

But because the two companies stand within inches of the Midtown Greenway, an attractive and heavily used bicycle and pedestrian trail, they’ve had public perception problems, Smith said. The smells, noise, smoke and truck traffic are incongruent with the “green” in Greenway.

“Their compliance history is very, very good,” Smith said. “We want them to pull back the curtain … build community trust and demystify their facilities.”

A key aspect of the pilot project is for the MPCA to build separate notebooks on each facility to detail and disclose what they do, what pollutants they emit, what systems are in place to lower emissions and how well the businesses have conformed to regulation. There’s also encouragement from the MPCA for companies in the program to spruce up their exteriors with trees and other landscaping to be good neighbors.

“In the pilot program we are all point source polluters,” said Ahlstrom, the foundry president. “Citizens are not trusting of our point sources.”