University at Albany Assistant Professor Aubrey Hillman and Graduate Research Project Assistant Sumar Hart collect lake sediment samples for climate-related research at Black Pond in the Adirondacks on Tuesday, June 3, 2025. (photo by Patrick Dodson)
Patrick Dodson
NEW YORK STATE — One of the greatest ecological success stories ever told is playing out right now in the lakes and streams of the Adirondacks — and it has happened within a lifetime.
Streams that were devoid of life in the 1980s, damaged by decades of acid rain, are teeming with life again. But the success could be short-lived, as policies being set in Washington today could be pushing New York to an ecological tipping point.
Artist Matt Burnett talks about one of his paintings of Adirondack life. Burnett grew up in the Adirondacks, worked as a DEC ranger and is now a professional guide.
Shaun Kittle
A crisis in a lifetime
Growing up in the late 1970s and 1980s, Little Tupper Lake and the trails, lakes and ponds around it were just part of Matt Burnett’s outdoor playground.
For a boy who would grow up to become first a Department of Environmental Conservation ranger, and later a professional Adirondack Guide and artist, it must have seemed perfect.
“I used to go out for a week with a backpack. I got accustomed to the space and going outdoors and getting out,” Burnett said.
But the seemingly pristine wilderness of his childhood was only superficially perfect; red spruce on the mountainsides and northern white-cedars in boggy wetlands were dying, and hundreds of lakes, streams and ponds were becoming barren.
The culprit was the air itself, or rather the rain.
Haider Khwaja
In the late ’70s and early ’80s, the rain falling across New York was far more acidic than it should have been, and is today. Sulfur dioxide from coal-fired power plants and nitrogen oxides – NOx – from car tailpipes mixed with water in the atmosphere to form sulfuric and nitric acids, says Haider Khwaja, an associate professor at the University at Albany and a senior scientist at the state Health Department’s Wadsworth Center.
“Sulphuric acid is a very strong acid that lowers the pH of the rain from 5.6 to way below… to 4 or 3.”
While water is considered neutral at pH 7, normal rain is always slightly acidic because some moisture mixes with carbon dioxide to form carbonic acid, giving it a pH similar to a banana or a cup of coffee.
Balanced by the minerals and soils of the Adirondacks itself, the slightly acidic rain wasn’t a problem for brook trout, insects and trees. But the precipitation that fell on New York in the late ’70s and ’80s had a pH that was closer to that of vinegar than normal water.
While acid rain can damage skin and worsen coughs and respiratory illnesses in people, it has a much bigger impact on the environment — trees start to die off because they cannot properly absorb nutrients from low pH soil.
“Deciduous forests, they are completely, quite damaged.”
“The soil was damaged. The trees were dead,” Khwaja said.
And the ecosystems that support fish crumble and parts of the food chain collapse, particularly in the lakes.
In the 1980s, the Adirondack Lakes Survey Corporation investigated 1,469 lakes and ponds in the Adirondacks; 352 had a pH under 5 and 346 were dead, with no fish found.
Omens in the sky
John Sheehan
John Sheehan, director of communications at the Adirondack Council, says you didn’t even have to leave the local cinema or your own backyard to see the problem.
Watch films from the era, “Serpico,” “Dog Day Afternoon,” or “The Godfather,” and you’ll see a “sick” skyline with a “bad haze hanging over New York,” Sheehan said.
“When I started in the Adirondacks, it was pretty rare to see a blue sky because there was so much haze in the air it never got blue until you got wind from the northeast to blow air directly off the Atlantic over our heads.”
“Fifty years ago, that problem was terrible,” Sheehan said. “Without having a wildfire anywhere, it was like having a wildfire now.”
That pollution – sulfur dioxide, lead and mercury came largely from factories and power plants in the Midwest, and automobile tailpipes in the west, according to Khwaja.
The Midwest, he said, solved its problem by having smokestacks 1,000 feet tall; “instead of impacting people in Cleveland and Cincinnati, [pollution] was getting up in the air and landing in another state — mainly New York.
“We had to work with the federal government to find a solution,” Sheehan said.
The Dave Johnson coal-fired power plant is silhouetted against the morning sun in Glenrock, Wyo. The Trump administration has repeatedly targeted regulations meant to curb emissions from coal plants.
By Recorder News
The solution
Congress first passed the Clean Air Act in 1970 and later amended it in 1977 and 1990. The act sought to curb smog and, by 1990, to limit releases of particulate matter, ozone, sulfur dioxide, nitrogen dioxide, carbon monoxide and lead. The law required states to control emissions that drifted across their borders; no longer did a tall smokestack suffice to call the air clean, and the government required industries to use the best available technologies to fight pollution.
The 1990 amendment directly targeted the pollutants that led to acid rain and created a cap-and-trade, or cap-and-invest system to incentivize industry, Sheehan explains.
“It set a limit on pollution, but allowed power companies to work among themselves to determine how they got there.”
The act didn’t outright stop pollution, but put a financial cost on it.
“A lot of people were worried,” Sheehan said.
They needn’t have been.
Instead of ten years, the nation met the act’s requirements in eight. Instead of costing $8 billion a year, it cost $700 million, Sheehan said.
Emissions fell faster and farther than expected. Now the scientists just had to wait and see if it worked. Would the trees and lakes recover, would the skies clear?
It would take Burnett’s entire lifetime before scientists declared over the last two years that they have the data to declare victory.
University at Albany Assistant Professor Aubrey Hillman and Graduate Research Project Assistant Sumar Hart collect lake sediment samples for climate-related research at Black Pond in the Adirondacks in June, 2025.
Patrick Dodson
An amazing success story
Studying the environment and climate isn’t for the overly pessimistic, says UAlbany Associate Professor Aubrey Hillman, because it is hard to show where nations have had the will to impose solutions and then find results demonstrating those solutions have worked.
Under the Clean Air Act, that is not the case; the results are unambiguous, Hillman says. It worked. While Sheehan points to crystal-clear blue skies on summer days as proof, Hillman points to something a bit more scientific — and a bit murkier and muddier: sediment samples.
Getting those samples isn’t always glamorous, but it is “100 percent” her “favorite part of the job.” Despite “many frigid nights and days knocking ice off boats, and getting muddy and dealing with black flies, and getting our gear in.”
That gear includes boats, life jackets and most importantly, clear plastic tubes that are sunk into the bottom of ponds to collect samples.
“It gives us a window into the past; it’s like a history book,” Hillman says of the cores.
Hillman can look at the samples and see the heavy toxic chemicals released from coal plants and leached from the soil by highly acidic water.
“Lead, mercury or arsenic. The type of things we don’t want because they can accumulate in the water and sediment and work their way up the food chain and make fish toxic to eat.”
Mercury, which is particularly dangerous to children and developing fetuses, can cause numbness, tremors, blindness, memory loss, seizures, permanent lung and brain damage and can be fatal; lead is particularly dangerous to children younger than 6 and can impact how the child’s body grows and brain develops, it is also fatal; arsenic can darken skin, cause lesions, cause digestive issues and kill.
“I think a lot of the people in the ’60s thought these problems were insurmountable,” Hillman said.
University at Albany Assistant Professor Aubrey Hillman and Graduate Research Project Assistant Sumar Hart collect lake sediment samples for climate-related research at Black Pond in the Adirondacks in June 2025.
Patrick Dodson
By analyzing the samples in a lab, Hillman can see, year after year, which chemicals were in the environment. Some events are big enough to cause a quick change — such as 9/11 and the COVID-19 pandemic. And when you look further back to the beginning of the Clean Air Act, a trend emerges in the data.
In the most recent sediment, the lakes and ponds are healthy again, Hilman said.
“The environment has the capacity to return to its ‘normal baseline state’.”
The samples have borne out “one of the few optimistic success stories we can paint,” she said recently back in her office as she was preparing to head back out asking new questions about climate change.
“What we are seeing on the ground is vastly improved surface water,” the Adirondack Council’s Sheehan says, who also points to falling mercury levels in the food chain.
A team of biologists, Barry Baldigo, Luis Rodriguez, Mike DeMoulpied, and Abbey Holsopple, from left, prepare to conduct a survey for invasive round goby on the New York State Canal system near Rome.
Scott George
A qualified success: Trout, the Adirondack canary in the coal mine
Recovery isn’t perfect.
Growing up near Rome, U.S. Geological Survey scientist emeritus Barry Baldigo enjoyed fishing the streams leaving the Park. In retirement, he now lives a stone’s throw from the Independence River and near the Blue Line. He spent his career applying science to the study of watersheds — particularly in the Adirondacks.
Before joining the USGS, he was one of the scientists who worked for the Adirondack Lakes Survey Corporation. As one of his final projects for the USGS, he returned to the park and found something very, very different — the fish were coming back to lakes and streams, in a “qualified success,” he said.
To gauge their health, Baldigo looked at fish populations, particularly brook trout, a species that can serve as a canary in the coal mine. Young trout are very sensitive to acidification, while adults are fairly tolerant and among the last species to be eradicated. If you don’t have any young trout, in 6 to 8 years, the trout will disappear altogether, Baldigo explained. To have a healthy trout population, the waters have to have recovered.
Since Congress amended the Clean Air Act, levels of acidity and dissolved aluminum – which is toxic to fish – in Adirondack waters have been falling. And since 1990, trout and other fish have been returning to barren streams.
“The brook trout populations in these small streams historically have been the only species in those streams.”
However, the life returning isn’t the same as it was 50 years ago.
“Brook trout are coming back, but other species are showing up, too,” Baldigo said.
The threat ahead
How long things might remain healthy is in doubt, and neither the scientists nor Burnett knows how long it might stay this way.
Recently, President Donald Trump has ordered changes to the enforcement of the Clean Air Act, exempting industrial facilities, coal power plants and data centers from its requirements.
A newly announced Amazon data center is expected to produce as much pollution as all of Switzerland, according to the New York Times and other media outlets. Amazon isn’t alone in the race to build bigger and bigger data centers. A single data center in Wyoming is expected to consume up to 1.8 gigawatts of power in the short term, which is five times what all the homes in the state consume. In the long term, the Wyoming data center could consume 10 gigawatts of power — enough juice for 7.5 million to 10 million homes, according to the U.S. Energy Department. There are 8.7 million homes in New York, according to the U.S. Census Bureau.
The changes to the Clean Air Act aren’t being driven by science, warn Sheehan and Hillman.
Will the loosening of regulations cause havoc in New York, as acid rain did in the late 1980s? The scientists wouldn’t, and possibly couldn’t say.
New York state’s Department of Environmental Conservation seems cautiously optimistic.
“It is unlikely that acid rain will return to New York to the levels experienced in the 1980s; however, the current federal government’s rejection of renewable energy in favor of more natural gas, oil and coal will have a negative impact.”
FILE – President Donald Trump holds up an image taken from his Truth Social account at an event about coal, Thursday, June 4, 2026, in the Oval Office of the White House in Washington.
Julia Demaree Nikhinson – AP
Some things might be too unpredictable to predict. While Trump has loosened regulations on coal plants, one of the key drivers of acid rain and mercury pollution before the 1990s, not a single megawatt of new coal power was added to the U.S. grid last year. And the AI data center boom could be headed for a bust, as many Wall Street analysts warn.
One of Sheehan’s worries is that if acid rain returns — even at a lesser intensity than it fell in the 1970s and 1980s — the soil may no longer have the ability to bounce back.
It’s a legitimate worry, Baldigo said.
“To some extent it is probably true the soils are already quite thin,” he said.
However, “it is hard to say if we are at that tipping point or not,” Baldigo said. “Whether or not a little more [acid rain] would cause that tipping point, people in the lake community and landscape community debate. It is certainly a consideration.”
“We have… a sensitive system, and we are pushing the limits of it.”
While science might not have all the answers, it can provide plenty of warnings.
“Lots of people have different opinions about different things to predict in legislation,” Hillman said. “The environment, or the economy… what is society’s No. 1 goal? Science doesn’t tell us which is the best to pursue, but what will happen if we pursue one path over another.”
“Environmental regulation can work,” Hillman says. “We often hear negative stories, or the specter of climate change being so enormous that it is hard to regulate.”
The Clean Air Act, however, shows “we can reduce mercury levels, lead levels. We can reduce acid rain. Lakes can recover.”
“My students hear some scary things. There are some scary things,” Hillman said. “We can take heart that we can have an impact on the environment in a positive way.”