State pollution regulators won't require further environmental review of a revised state permit for a controversial metal shredder on the north Minneapolis riverfront.

The citizen board of the Minnesota Pollution Control voted 6-1 at a special meeting Monday to consider the revised permit on Oct. 23 without requiring further study, as its staff recommended before the day-long hearing.

If the proposed permit is issued after almost a year of debate, that will put shredder operator Northern Metals in compliance with state air quality standards for the first time since shortly after the machine began dicing scrap metal in 2009. Company President Stephen Ettinger said he had no comment on the decision.

The vote came despite pleas for more study from three area legislators, North Side residents and advocates. Some argued that further assessment would better define whether the pollutants released by the shredder affect human health and also look into environmental justice issues raised by having the facility in a heavily minority and often low-income population. City officials said about 18,000 people live within a mile of the shredder.

But the agency's staff said that although statistical modeling found that air quality standards would be violated by the cumulative effect of area businesses emitting small particle pollutants, the shredder would contribute only about 2 percent of that load. They said that the state will install air monitors to keep closer tabs on the pollution, and has begun working with major area polluters to cut what they contribute.

The proposed permit sets an initial limit of slightly under two pounds of fine particles per hour, although that could go up after three years under certain conditions. The current limit is about 25 percent of that level but agency staff said that the proposed limit also takes into account particles that form in the condensing of shredder emissions. The company sought but later dropped a limit of more than four pounds per hour but agency staff said at that level they would have urged an environmental impact statement. The proposed permit converts the current daily limit to what it called an equivalent annual limit of three pounds. Testing would occur every five years.

The proposal also would end the prohibition on the shredder consuming auto hulks, rather than the pieces of cars it now is fed. The agency said such material must still have contaminants removed before processing.

The riverfront site at 2800 Pacific St. N. has been used as a yard where scrap metal is collected, sorted and shipped off to market since 1951. The proposal to raise the value of that scrap emerged in 1989 when a previous owner put down a deposit on a shredder but it took 20 years of political, legal and regulatory debate for Northern Metals to begin operating it.