A new report from the Lake Champlain Basin Program provides a comprehensive update on an array of indicators of the health of the lake. It shows serious problems remain with phosphorus pollution in the lake and also notes some ongoing successes with regard to invasive species.
The report, called the “State of the Lake,” is designed to give citizens and policymakers in the Lake Champlain Basin a comprehensive snapshot of how the lake is doing. Since the survey is conducted regularly (the last one came out in 2012), the program is also able to point to trends that show which indicators are improving and which still need work.
Overall, the report says the majority of the lake is in good health.
“Although the water quality trends in Lake Champlain are cause for concern, it is important to know that more than 85 percent of Lake Champlain’s water is consistently of excellent quality and another 13 percent of the water is usually in quite good condition,” the report’s introduction says.
The report notes significant progress in addressing invasive species like sea lamprey and water chestnut.
For the first time since 2010 (and the second time since the late 1980s), the number of sea lamprey wounds per 100 salmon sampled was within the target rate (15 or below). The rate for lake trout is trending downward, though it’s still above the target rate of 25.
“Lake Champlain’s water chestnut control program is a long-standing success story that remains dependent on steady funding and support from state, federal and local partners,” the report says. In Missisquoi Bay, for example, the report says the water chestnut population was reduced by 96 percent between 2007 and 2014.
Bill Howland, the director of the Lake Champlain Basin Program, cautioned while presenting the report that things aren’t all going in the right direction. The “main lake,” central part of Lake Champlain that makes up 65 percent of the lake’s overall volume, isn’t getting better.
“In the main lake,” Howland said, “even though the main lake standards are very strict, we are not making those standards and there is a trend that is going in the wrong direction. It’s getting a little more phosphorus concentration rather than less.”
While phosphorus concentrations remain above target levels in almost every part of the lake (10 of 13 lake segments), the report points out that most of the lake is swimmable most of the time, and that water supplies drawing from the lake “rarely need to shut down distribution due to source water quality.”
The report shows that water flowing from Vermont, New York and Quebec carries an estimated 921 metric tons (2.03 million pounds) of phosphorus into Lake Champlain every year, and phosphorus from Vermont makes up the majority of that load. Of the total, 630 metric tons (68 percent) comes from Vermont.
Vermont’s phosphorus contribution to Lake Champlain comes primarily from agricultural land, which is responsible for 40 percent. Another 16 percent, however, comes from developed land. Runoff from streets, rooftops and other human-made impervious surfaces doesn’t always have a chance to be filtered through topsoil, so phosphorus washes directly into the streams and rivers that feed Lake Champlain.
Phosphorus pollution from Vermont also comes from forests (16 percent), wetlands (1 percent), streambank erosion (20 percent), and wastewater treatment plants (4 percent), according to the report.
Pollution into the lake, both from phosphorus-fueled cyanobacteria (blue-green algae) blooms and wastewater treatment plants that overflow during wet weather, led to more than 55 beach closures between 2012 and 2014, the report said.
The report doesn’t offer comprehensive policy suggestions to address the problems facing the lake, but Lake Champlain Basin Program Director Bill Howland said public buy-in is a must for significant progress on water quality,
“If there is a magic bullet – I love to dream that there is – if there is a magic bullet it is for everybody in the basin to understand that the problems in the lake come from what they and their neighbors and our neighbors all do on the landscape,” he said. “And it means that in every household if we make an actual effort to reduce our phosphorus footprint, we’ll make an enormous change and yes, we could turn this around very, very well if everybody participates. Failing that, we’re not going to succeed.”