There were a couple of stops during the tour of the St. Peter sewage treatment plant where the state senators and staff might have been tempted to demand an immediate transfer to a different committee.

Sen. Ellen Anderson — the chairwoman of the Environment, Energy and Natural Resources Budget Committee — never faced a revolt, however, even when the aromas reached breath-taking levels. It was Anderson’s idea to lead her committee on a tour of the wastewater treatment plants in Shakopee and St. Peter Wednesday.

“There’s no substitute for seeing this firsthand, smelling it firsthand” said Anderson, DFL-St. Paul. “It makes it real and makes you understand what it takes to clean up our wastewater.”

Anderson’s committee will be facing hundreds of millions of dollars in requests next year for state assistance for municipal sewage treatment, so she felt an additional need to sniff around the technology and techniques being used in the wastewater business.

And while Anderson wasn’t exactly taking her committee on a tour of the Minnesota Landscape Arboretum or the St. Paul Conservatory, she did pick the best of the best in sewage treatment. The wastewater plants in Shakopee and St. Peter were suggested by the Minnesota Pollution Control Agency as the top facilities in the state.

“They set a really good example here, I think, for a lot of communities around the state,” she said.

St. Peter Mayor Tim Strand joined the tour, as did City Administrator Todd Prafke and Sen. Kathy Sheran of Mankato, who represents St. Peter in St. Paul.

“We’re happy to show off St. Peter, especially after the tornado,” Strand said. “The wastewater treatment facility isn’t my first idea of what I’d like to show off, but we’re very proud of it. It’s an incredible state-of-the-art facility.”

The $20.1 million plant began discharging its effluent into the Minnesota River in February of 2004, replacing a 202-acre pond system that was located in the river’s flood plain and often was overrun by high water. In addition to eliminating that problem, the new plant is uncommonly efficient at minimizing the pollution being dumped into the river.

Pete Moulten, the city’s water resources superintendent, explained why.

At the heart of the plant’s design, based on European technology, are six 30-foot tall filtration towers. Each contains countless polystyrene beads, smaller than a pea, that provide a place for a microorganism-infused biofilm to attach. The biofilm converts the tiny bits of organic material in wastewater into biomass.

Prafke provided a translation.

“Those beads are a good surface area to hold the bugs that eat the crap,” Prafke said.

The end result is that St. Peter is extremely well positioned to deal with increasingly stringent state and federal standards for the amount of pollution that cities can discharge into rivers like the Minnesota. When it comes to phosphorus, for instance, the city’s wastewater plant dumps less than 1,100 pounds into the river each year — 2,300 pounds less than what pollution standards allow.

That means the city has plenty of room to add new industry. And in the future, it may be able to generate revenue for city coffers by selling phosphorus “credits” to other cities with less sophisticated sewage plants to allow them to meet pollution standards.