July flooding pulled nutrients, waste into Vermont's waters — and climate change is making it worse
By July 13, the floodwaters from the Lamoille and Gihon rivers had largely retreated from Johnson, but at David Camley’s Main Street apartment, the air still smelled like No. 2 fuel oil.
“I didn’t get flooded, thank god, everybody else down there did. It’s a mess. No. 2 fuel oil leaking in this building real bad for three days. And just this morning, they’re still pumping it out,” said Camley. “This morning it started to get better. I opened my door up and I tried to air it out some, cause I got a dog and she was getting sick from it. And me too, not sleeping, smelling that for three days.”
At the peak of the flooding in July, more than 4 billion gallons of water flowed into Lake Champlain every hour carrying fuel oil, mercury, diesel, and phosphorus from upstream communities.
There were more than 200 flooding-related hazardous material spills reported in the state as a result of the July floods. Regulators are unsure of the quantity of most of them.
It’s easy to know how much has spilled when leaks occur in controlled environments, like when a leak is discovered in a recently-filled tank of heating fuel or a car’s gas tank, said Tim Cropley, program manager of the Vermont Department of Environmental Conservation’s Hazardous Materials Spills program.
“In a case like [the recent flooding], we don’t necessarily have any idea how much oil was in a tank,” Cropley said. “So there’s going to be a lot of unknowns for everything related to this disaster as far as volume or amount released.”
Data from the state shows clusters of reported spills in Barre, Montpelier, Cambridge, Johnson, and Ludlow, all hard-hit by flooding. Floodwaters overturned basement fuel tanks and dislodged farming equipment. In Barre, water from the Winooski River inundated a hazardous waste disposal site storing mercury-laden fluorescent bulbs and lithium-ion batteries.
Additionally, wastewater facilities in Johnson and at least 23 other facilities around the state were either completely or partly compromised, sending raw or partially treated sewage into Vermont’s rivers.
Despite all of that, Cropley said, Vermont’s rivers aren’t likely to face much of a long-term impact.
“Essentially, the oil would get washed downstream, especially with the amount of flow that we saw,” Cropley said. “That doesn’t mean we don’t pay attention to [spills]; if there’s areas where there seems to be a remaining impact from oil that would be investigated.”
But spills aren’t the only danger to Vermont’s waterways.
Floods bring sediment and nutrients
“There was a huge amount of rain that fell on our watershed and this all collected to become an incredible amount of water that came into the lake itself,” said Matt Vaughan, chief scientist at the Lake Champlain Basin Program, a science nonprofit that has been tracking water quality there for 30 years.
Lake Champlain, 435 square miles across, rose almost 3 feet, reaching levels that would be normal in spring but heavily abnormal in fall. The lake did not reach flood stage, but the immense amount of water brought in an equally immense amount of sediment and nutrients.
The flood delivered 103 million kilograms total phosphorus (phosphorus in any form, dissolved or particulate) into the Lamoille River, a tributary of Lake Champlain, between July 10 and 17, according to estimates by the Department of Environmental Conservation. That’s more than the river carried in the entirety of last year, said Vaughan.
Along with the phosphorus, the flood waters brought large amounts of sediment into the water, turning it increasingly opaque. On July 10, the Lamoille River’s turbidity, or cloudiness, went from 3 FNU — that’s Formazin Nephelometric Unit, a measure of turbidity calculated by shining an infrared light through water and detecting how much is scattered by a sensor perpendicular to the beam — to a peak of 4,099 FNU that evening.
“With increased turbidity we have several impacts. Because there is less light moving through the water, there is less opportunity for our phytoplankton to grow, and that’s the base of our food webs. That can be a stressor for fish because there may be less oxygen in the water, and there’s less food going around,” Vaughan said. “And then also for fish, with less visibility, it can be harder for them to hunt and eat their dinner, because they can’t see other fish moving around quite as well.”
Climate change means current measures aren’t enough
Vermont is required to limit the amount of phosphorus that enters its water supply by the EPA via a Total Maximum Daily Load. This requires the state to reduce the amount of nutrient runoff by, for example, regulating agricultural activity and mandating infrastructure improvements like separate storm- and wastewater systems to prevent sewage from being carried into the water by flooding.
In recent years, however, some environmental advocates in the state have called for a more aggressive approach than what the EPA mandates, saying climate-change-fueled extreme rain events jeopardize public investments in clean water.
The Environmental Integrity Project, a national nonprofit that advocates for clean water, analyzed data to find climate-change-fueled extreme events has already undermined public investments in cleaning up the Chesapeake Bay.
“The more rain we have because of climate change, the more nutrient pollution we have in our rivers and streams, which means more algal blooms, more sediment washed into our rivers and streams,” said Tom Pelton, a spokesperson for EIP. “And so climate change and rainfall has a direct and immediate impact on water quality that people don’t always think about.”
Recovery and looking to the future
The July flooding alone isn’t going to jeopardize water quality in Lake Champlain, said Vaughan, the Lake Champlain Basin Program scientist. Sediment settles at the bottom of the lake, and oil floats on water, which carries it downstream. The phosphorus may result in increased cyanobacteria blooms when the weather gets warmer and drier. Johnson’s wastewater plant isback online.
But floods of increasing intensity and frequency do pose a threat. The data shows that the conditions that lead to floods in Vermont and New England are getting more common and more severe. And while extreme floods long predate us, fertilizer use and the straightening of rivers, increasing their speed and power, contribute to greater amounts of nutrients being deposited in our lakes and rivers.
A lot can be done to reduce the impact of flooding, said Vaughan. Municipalities can install green stormwater infrastructure and separate storm- and wastewater systems. Protecting and restoring wetlands can provide a buffer against nutrient runoff and slow floodwaters. Vaughan also recommends reconnecting rivers to their floodplains by removing artificial barriers along the edges of the river.
“Floodplains not only slow waters down and spread water out as it’s moving downstream, they can also be a place of deposition for sediment and nutrients,” said Vaughan. “Plants growing in floodplains can take up nutrients, the sediment can settle out as floodwaters recede; so the more we can reconnect those floodplains and wetlands to the river, the better off we’ll be with these more extreme events.”
Have questions, comments or tips?Send us a message.