MONTPELIER, Vt. — Federal and state officials plan to hold public meetings in Vermont on efforts to clean up Lake Champlain.

The sessions, starting Monday, are the next step in what some environmentalists say has been a long, drawn-out process of coming up with a plan to reduce the water’s phosphorus levels, blamed for toxic algae blooms.

Runoff from farms, wastewater treatment plants and developed properties are among the primary sources of phosphorus. The summertime algae blooms, which a top state official described as worse this year than any in memory, have plagued the South Lake, the Missisquoi Bay, St. Albans Bay, and the Inland Sea, also known as the Northeast Arm.

“Vermonters love Lake Champlain and truly care about the health of the streams that flow into it,” Commissioner David Mears of the state Department of Environmental Conservation said in a statement.

The battle over runoff has focused on Vermont because the parts of New York state that border the lake have fewer farms and less development.

Mears said Vermont is committed to working with the federal Environmental Protection Agency to include “the most strategic, cost-effective practices” to restore the lake.

The meetings are part of a yearslong effort to come up with a plan specific to environmental standards as expressed in TMDLs – “total maximum daily loads,” or the maximum amount of pollution allowed to enter the lake.

Christopher Kilian, Vermont director of the Conservation Law Foundation, noted that nearly four years have passed since the EPA in 2011 rejected a cleanup plan Vermont drafted in 2002. By federal law, the EPA was supposed to produce a new TMDL report within 30 days, a deadline Mears said was unreasonable.

Lynne Hamjian, the EPA’s deputy director of ecosystem protection for New England, said the agency has been busy with “extensive outreach” to Vermont officials and residents about the issue, and the project is “quite complex.” A final plan should be out by early summer, she said.

A lawsuit by Kilian’s group led to the EPA action.

“It (the meetings) will be the first time the EPA really lays out the direction that it’s headed in on all the various sources of the phosphorus that are dumping into Lake Champlain,” Kilian said.