The federal government’s new pollution limits on Lake Champlain will most likely entail changes to local ordinances and agricultural practices and require additional stormwater treatment within urban areas.

The Environmental Protection Agency’s proposed change would require Vermont to reduce the amount of phosphorous reaching the lake each year by 39 percent, or 188 metric tons.

Who will pay and how much are the questions Vermonters will have to resolve in the next few months, but it is already estimated customers of stormwater treatment facilities could be forced to pay millions in new fees.

“There’s something in this for everybody in terms of pain and responsibility,” said Eric Smeltzer, an environmental scientist with the Agency of Natural Resources, who spoke with the Friends of Northern Lake Champlain group in St. Albans last week.

In 2010, EPA revoked its approval of Vermont’s total maximum daily load, or TMDL, for phosphorus, which causes toxic blue-green algae growth. State permits for stormwater discharge, including those for wastewater treatment facilities, are based on the TMDL.

The EPA first approved a TMDL for Lake Champlain in 2002, calculated with data from the 1990s.

The EPA will redo Vermont’s TMDL as part of a new and ambitious effort to remove phosphorous before it gets into the state’s waterways from agricultural lands and impervious surfaces such as roads and buildings. The new limit will be released next year.

However, preliminary numbers show the lake receives 317 more metric tons of phosphorous each year than it can handle. Divided over the various watersheds, Missisquoi Bay needs a 64 percent reduction and St. Albans Bay a 48 percent reduction.

If Missisquoi Bay’s phosphorus levels were cut 75 percent, it would reach acceptable levels, defined as 25 micrograms per liter. Cutting by 25 or even 50 percent did not reach the acceptable level, even after 30 years, EPA data shows.

Both St. Albans and Missisquoi Bays have large amounts of phosphorous in their soil beds. Even if reduction targets were met, those two bays would take longer than the rest of the lake to show the effects, Smeltzer said.

Upgrading the state’s wastewater treatment facilities to achieve maximum possible phosphorous removal would cost millions. Changing the filters at the St. Albans City facility alone would cost at least $2 million, Wayne Aldrich of Aldrich + Elliot reported earlier this year.

Such upgrades are “definitely not the best use of our dollars,” said David Mears, commissioner of the Vermont Department of Environmental Conservation.

Mears estimates the state will need to spend $15 million to $20 million annually over the next 10 to 20 years.

“We’ve got to be brutally honest; we’ve got to be in this for the long haul,” Smeltzer said.

Since the devastation caused by Tropical Storm Irene, ANR decided the state needs to change its approach to stream management.

Keeping development away from rivers and streams so those streams can pool in floodplains is now considered the best way to prevent future floods and improve water quality over the long term, according to Mears.

That could mean changes to ordinances limiting development in floodplains and along stream banks. ANR has already begun advocating changes to local ordinances.

In the St. Albans Bay watershed, cropland is the primary source of phosphorous, at 52 percent.

The state has relied on the carrot of financial assistance, often from federal agencies, to entice farmers to adopt best practices like installing stream buffers, planting cover crops in the winter months and reducing tillage.

It’s uncertain which, if any, best practices will be mandated.

The state will need to look at all farms, not just large-scale dairying operations, Mears said. “We need to do more outreach to those folks,” he said of smaller farms.

Mandated stormwater planning for communities is a possibility for reducing runoff from urban areas to include identifying sources of runoff.

The Friends of Northern Lake Champlain is working with several Franklin County communities on precisely that, but the project will need to be implemented on a much larger scale to achieve the kinds of reductions required by the TMDL goals.

Stormwater permits for roads, both state and local, are another possibility under discussion.

Within 20 years, Vermont will need to design, build and maintain its roads differently, suggested Mears, who pointed out that designing roads to minimize erosion is  a smart investment.

ANR will present a phosphorus plan to the legislature in January and will hold a series of public meetings later this year about what’s at stake.

The new TMDL provides “an unprecedented opportunity for people to sit down at the table and develop practical, pragmatic solutions,” Mears said.

Asked if residents of eastern Vermont would be willing to pay for Lake Champlain cleanup, Mears said the Connecticut River and Lake Memphremagog have many of the same problems as Lake Champlain, and any changes the state adopts would benefit those water bodies as well. The three watersheds combined cover 94 percent of the state.

“It’s the best shot that can be taken,” Smeltzer said of the new TMDL. “It’s still a combination of the best scientific information and some guesses in some cases.”

Ed. note: This story combines a two-part piece printed in the St. Albans Messenger earlier this week.