BURLINGTON, Vt. (WCAX) – Uprooted trees, ripped-up houses, sewage and debris are all clogging up Vermont’s waterways after this month’s big storm, compounding existing water quality issues in Lake Champlain.
Lake-goers might be noticing giant tree branches or floes of trash out on the water, but experts say it’s the smallest bits of rubble that pose the biggest threat.
“We are kind of battling an increase of flow over time and more nutrients coming downstream,” said Matthew Vaughan of the Lake Champlain Basin Program, who is using high-frequency water quality monitoring devices placed around the lake to understand what this round of flooding swept in. “We got excellent monitoring data throughout the period of the storm.”
One key piece of data is turbidity levels or the cloudiness of the water caused by fine sediment torn from shorelines.
“That’s going to transfer from our rivers to the lake and it’s going to continue to mix in the lake over the course of one to three weeks,” said Vaughan.
The massive yellow plumes of sediment are impossible to miss out on the water. Despite their size, Vaughan says last summer’s flooding brought about three times more sediment. Though he’s still analyzing the data, he says that likely means less nutrients like phosphorus dumped in the lake this go around.
Another concern is the amount of trash caught up in the floodwaters. University of Vermont hydrologist Anne Jefferson is working to collect that data.
“We suspect that an event like this would be a big mover of plastic pollution,” Jefferson said.
While any level of plastic pollution is a concern, she says microplastics are the hardest to clean up.
“They’re not going away, they’re just getting smaller. You don’t have a technology that can take microplastics out of the environment at scale,” Jefferson said.
Wildlife can ingest those tiny bits of plastic, leading to a host of health and food chain issues.
“We may be sort of subtly changing the base of the ecosystem by just creating new habitat and sort of novel substrates that wouldn’t normally be there,” said Jefferson.
A larger analysis of plastic pollution, phosphorus levels and other nutrients that flowed into the lake should come out later this year. In the meantime, lake experts recommend paying attention to local beach closures due to bacteria such as E. coli.