The agriculture and environment bill that became a final hurdle in completing the 2015 legislative session includes a dozen provisions with far-reaching implications for Minnesota's environment and the way the state regulates polluters.

Passed by the Senate on Friday but not by the House, the final outcome of the legislation remained in doubt. But the Senate-passed bill was the source of heated divisions among lawmakers that set the stage for the continued rancor at the Capitol.

In a development that outraged a number of Senate DFLers, some of the provisions were inserted during late negotiations, without the benefit of committee hearings or floor debate, and received little public scrutiny during the regular session.

One of the bill's key elements, regarded as a victory for Gov. Mark Dayton, would strengthen a state law that requires farmers to install natural buffers of grasses, trees and shrubs along lakes, creeks and rivers to prevent runoff of agricultural pollution.

Water quality advocates hailed it as one of the most significant pieces of environmental legislation in years, but farm groups said it was inflexible and an overreach of government. It was approved in the Senate after Dayton agreed to allow more site-specific flexibility, but it requires an average 50-foot buffer along a waterway. It also would require 16½-foot buffers along most agricultural ditches, and gives the state increased authority to penalize those who don't comply.

A second provision, designed to attract biofuel plants to Minnesota, would create incentives eventually worth up to $6 million a year in subsidies. To be eligible, the facilities would have to use at least 50 percent perennial grasses or cover crops to make the fuel, reducing the amount of agricultural land devoted to row crops, the state's leading source of water pollution. In the first year, it would provide $2 million in funding, enough for two small plants to get started.

Still uncertain was the fate of the Citizens' Board that holds significant power over decisions by the Minnesota Pollution Control Agency (MPCA). Republicans and corporate interests see the board as an unnecessary and unpredictable impediment to regulatory approval. Environmentalists and DFLers were furious about a last-minute deal that would have eliminated the board, which they see as a critical forum for the people most affected by pollution and development. Late Friday, different versions of the bill left the status of the Citizens' Board unsettled.

In other provisions, the bill would:

• Permit commercial nurseries to label their plants as "pollinator friendly," even if they are grown with insecticides that can make the flower toxic to insects. If nurseries test their plants, and find that insecticide concentrations are below what it would take to kill a bee outright, they can label the plant as attractive to pollinators. The provision, passed at the urging of the state's nursery industry, changes a 2014 law that forbade such labeling for plants that contain the controversial insecticides called neonicotinoids.

• Suspend water quality rules to protect wild rice until the MPCA completes a rule-making process for the pollutant sulfate, which could take years. It also would prevent the MPCA from asking industry, primarily taconite mines and water treatment plants, to spend money on reducing their sulfate emissions into water where wild rice grows.

• Exempt PolyMet Mining Co. and other copper mines from toxic-landfill rules. Taconite mines have been exempt for years, in part because they were operating before landfill laws came into effect. Also, taconite mines placed their toxic waste almost exclusively in tailings basins, which are regulated by permits. But the proposed PolyMet mine and processing facility could generate different kinds of toxic waste that would require other kinds of disposal. Proponents say they want to give copper mines the same regulations as taconite mines, and that the state agencies will manage the new kinds of pollution through permitting as well. Opponents say the pollution risks of copper mining are much higher, and that it should be held to the same standards as other industries.

Josephine Marcotty • 612-673-7394