COL Silver Lake plant should meet Clean Air Act terms

Rochester Public Utilities studies pollution issue

At a recent public hearing, the Minnesota Pollution Control Agency's Citizens Board approved a permit for Rochester Public Utilities to proceed with a steam project to serve the Mayo Clinic.

In an unexpected move, the board also asked RPU to develop plans for providing the steam to the clinic without raising the level of pollutants emitted from the Silver Lake Power Plant. The board asked RPU to appear before it again on Nov. 25 and present its plan for carrying out the project without raising the level of emissions.

The RPU board already had directed utility plant officials to achieve an even more difficult goal. They were asked to determine what it would take to make a substantial reduction in the level of pollution produced by the Silver Lake Plant. Larry Koshire, general manager, said the utility would need to retain specialists in this field to conduct such a study and that the process would take four or five months.

; These steps followed several months of protests by the Rochester Energy Future Coalition, a citizens' group said the Silver Lake Plant, which is coal-fired, creates more pollution per unit of energy produced than any other plant in Minnesota. It criticized RPU for entering into a contract to produce high pressure steam for the Mayo Clinic because it would require burning 73,000 more tons of coal per year when the project reached full production.


The group produced testimony by physicians that fine particulate matter and chemicals produced by the Silver Lake plant can cause respiratory disease and harm asthma patients. Physicians also testified the rate of asthma in children in Rochester from kindergarten to grade 12 was 12.8 percent between 1997 and 1999, a figure substantially higher than the national rate. The oldest boiler at the plant was installed in 1949.

In directing Koshire to prepare a plan for making substantial reduction in the level of pollutants produced by the Silver Lake plant, the RPU board had already imposed a stiffer requirement than the one requested by the MPCA Citizens Board. The MPCA officials asked only that the steam project not cause an increase in emissions.

; In either case, it would appear that significant expenditures and major changes in the plant will be required. It does not make much sense for the utility to order major improvements merely for the purpose of maintaining the current level of pollution, which is unsatisfactory. So long as change is required, RPU should determine how much it would cost to meet the standards of the federal Clean Air Act.

This is especially true since the federal government is expected to require all coal-fired plants to meet those standards in the next 10 years. The oldest coal-fired plants were exempted in the 1970s because it was believed they would eventually be replaced by newer plants that would meet the standards. That didn't happen and many operators of the plants, including RPU, kept them in use without meeting the standards.

The public will be served best if the RPU staff can produce a plan for meeting the standards of the federal Clean Air Act. Then it will be up to the RPU board and the citizens of Rochester to determine how such an improvement can be financed.

That is something that will have to be done in any case when higher federal standards are imposed.

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