VERMONT — An international water panel has released initial recommendations for reducing phosphorus pollution in northern Lake Champlain, ranging from switching crops to setting up a phosphorus import-export budget. 
The report, which is out for public comment until Dec. 14, is part of a broader lake pollution study the International Joint Commission is doing at the request of Vermont and Quebec. The IJC aids the U.S. and Canada in resolving boundary waters issues. The IJC is holding a public meeting on the draft report Thursday at the St Albans Museum from 7-9 p.m. 
The IJC contracted with the Vermont-based Lake Champlain Basin Program, the Quebec-based Organisme de basin versant de la baie Missisquoi and the New England Interstate Water Pollution Control to write the report. 
Missisquoi Bay, the northeastern, border-straddling tip of Lake Champlain, has some of the highest phosphorus levels in the lake. Excess phosphorus can lead to toxic cyanobacteria blooms, which have been a “significant issue” in this part of the lake since the ’90s, according to the ICJ report. 
Vermont and Quebec have been working to reduce phosphorus going into Lake Champlain for decades. In 2002, the two governments signed an agreement to reduce phosphorus in the bay to a low level of 25 micrograms per liter by 2016. But in-lake phosphorus levels remain roughly twice that targeted amount. While the IJC cannot order either government to take action, the hope is that their recommendations will accelerate and better coordinate lake cleanup efforts on both sides of the border. 
Vermont, where almost 60% of the Missisquoi watershed sits, is now required by a 2016 federal order, called the Lake Champlain TMDL (Total Maximum Daily Load), to reduce phosphorus going into that part of the lake by 64% over the next 20 years. Agricultural runoff contributes to around 58% of the phosphorus pollution going into the Missisquoi Bay from the Vermont part of the watershed, while streambank erosion contributes 40% and runoff from forested land contributes 20%. 
While Quebec does not have a similar federal mandate to reduce phosphorus pollution, the province did revamp its clean water program last year — including setting aside half a billion dollars investment over the next five years. 
“I would argue that there’s a lot of aggressive actions being taken to address the TMDL already,” said Eric Perkins, Vermont TMDL coordinator. “So it’s not that those are not enough necessarily, it’s that the study advisory group looked at things on both the Quebec and Vermont side … (that could) make a bigger impact to speed up the phosphorus reduction.” 
The two governments’ lake cleanup efforts are complicated by so-called “legacy phosphorus” that farmers applied in previous decades, which has built up in soils. Also, certain conditions cause phosphorus that has accumulated in the bottom of the lake to be released, fueling cyanobacteria blooms. 
And climate change is only expected to worsen the problem. Vermont is already seeing more intense storms, which can increase phosphorus-laden runoff. Also, warming waters create better conditions for cyanobacteria blooms. 
“If left unchecked, continued warming and related hydrologic impacts will increasingly undermine the achievement of our water quality goals,” state the report authors.   
The Missisquoi Bay report contains two main sets of recommendations: better coordinate international lake cleanup efforts and reduce phosphorus pollution coming from the farming sector. 
The authors recommend that the two governments set up a more formal international “phosphorus reduction task force” to ensure that efforts on both sides of the watershed will halve the in-lake phosphorus reduction. As it stands, Quebec does not have as binding of a mandate to reduce phosphorus levels in the bay as Vermont does under the Lake Champlain TMDL agreement with the Environmental Protection Agency.
“From my perspective, the key takeaway is that any action really needs to be done on a binational basis,” said Kevin Bunch, communications specialist with the IJC. 
The report suggests the two governments create a phosphorus import-export budget to better understand what is coming into the watershed, mainly in the form of feed and fertilizer, versus what is taken up by crops or ingested by livestock. 
Vermont’s phosphorus imbalance peaked in 1950 and farmers use significantly less fertilizer today, according to a 2018 paper authored by University of Vermont and McGill University researchers. However, on-farm animal density ballooned during the same time period and manure continues to be a source of phosphorus pollution, the 2018 paper says. In an effort to reduce that imbalance, Vermont recently announced recipients of state funding to scale up phosphorus removing technologies. 
Over the past 30 years, the Missisquoi watershed has experienced a “significant increase” in the amount of farmland used for corn and soybean, according to the report. Corn and soy have a higher per acre phosphorus contribution; the report authors recommend providing incentives for farmers to transition away from those crops. 
“I think it’s important that you have crops in the ground that aren’t necessarily going to be so phosphorus intensive,” said Bunch. “That doesn’t mean you can’t grow these other crops but we do suggest it’s probably a good idea to have a … mix.” 
There are multiple federal and state programs available for Vermont farmers looking to switch to grazing or organic farming. For example, the state Agency of Agriculture, Food and Markets is now paying farmers for rotational grazing under its farm agronomic practice program, said Laura DiPietro, director of the agency’s water quality division. 
The report also recommends farmers adopt more on-farm water quality management practices, like cover cropping and more rigorously assessing fertilizer application. This has been an area of renewed focus in both Quebec and Vermont in recent years; among the many requirements of Vermont’s landmark 2015 Clean Water Act was that the state’s agriculture agency revamp existing on-farm water quality practices into a new set of rules called “required agricultural practices.”