A major figure in efforts to clean Lake Pepin and the Mississippi River of sediment is leaving the Minnesota Pollution Control Agency, frustrated with the state's process for the cleanup.
Norman Senjem, the agency's Mississippi River Basin coordinator, will retire on Sept. 27.
In a farewell note to colleagues, he lamented how difficult it has been to establish scientific consensus about the sources of sediment.
Senjem, who has worked for seven years on the project — an effort that included research and seeking input from farmers, scientists and others — also warned that farmers would not change practices that send sediment into the waters until state officials hold them accountable.
A Pollution Control Agency report concludes that farms in the Minnesota River valley are responsible for three-fourths of the sediment that is choking Lake Pepin. The agricultural area also is responsible for much of the phosphorus and nitrogen in area waters.
For the most part, cities have cleaned up their wastewater treatment systems, and factories no longer spew chemicals into the river.
But farms contribute to what's called non-point pollution, substances that cannot be easily traced to a specific source. The federal Clean Water Act, exempts farms from its requirements.
Minnesota and other states have relied on voluntary measures and incentives to control such pollution, including payments to farmers who reduce plantings of corn and soybeans and turn marginal land back to hay.
But those programs have been in place for years, and recent studies say Minnesota's rivers continue to be plagued with nutrient and sediment pollution.
Senjem said additional measures are needed. He said state rules that control pollution from feedlots are a good example of how regulations lead to improved management.
"We've been very effective in southeastern Minnesota on smaller feedlots with education, technical assistance and cost-share," he said. "There is an element of regulation: a last resort. If you don't do this voluntarily the county or state might enforce against you."
Senjem also thinks a concept proposed in a recent University of Minnesota report could help. Under the proposal, state officials would monitor the mouth of each of the state's 81 major watersheds for pollutants and water flow to set a target for allowable pollution and water flow levels.
Institutions and residents within that watershed would be held responsible for holding pollution to the allowable limit. The state could award subsidies to areas that meet the limits and assess financial penalties to those that did not.
For example, the government could cut crop subsidies if residents did not achieve the target. Local governments could lose state assistance.
Representatives of agriculture groups say more research is needed before regulations are justified.
Warren Formo, executive director of the Minnesota Ag Water Resources, said the state does not have enough specific information about where the problems are.
"Farmers now think, 'if everything's a problem, there's no prioritization to help me address the true problem.' " he said. "If you'll help me find the 5 or 10 percent that needs to be addressed, I can work on that."
The idea of creating penalties for polluting farmers would amount to a revolution in a state where farming and farmers are regarded with respect bordering on reverence.
So far, Senjem's bosses at the Minnesota Pollution Control Agency prefer to the voluntary approach.
They point to developments nationally that they say will eventually push the agricultural sector to control pollution. The federal Environmental Protection Agency is focusing extra attention on the Chesapeake Bay and the Gulf of Mexico, which face similar problems to Lake Pepin.
For the Chesapeake Bay, the government is considering financial penalties for pollution, similar to the approach Senjem thinks might work in Minnesota. If the Gulf of Mexico is declared an impaired body of water, the federal government will require Minnesota and other states to contribute to a solution.
Such developments will eventually nudge farmers to act, said Rebecca Flood, the pollution control agency's assistant commissioner for water.
"I think once producers understand, and we come to a joint understanding about the science and those types of things, they'll move," she said. "They'll do what they need to do."
Flood says the agency is committed to taking Senjem's report to the next stage — which means spelling out who needs to do what to solve the sediment problems in Lake Pepin.
Senjem plans to take a part-time job at the Zumbro Watershed Partnership in southeastern Minnesota. He hopes farmers and others will be more open to his ideas once he no longer speaks for the MPCA.