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Episode 9: What Happened to Acid Rain?



MATT DOZIER: Hi everyone, welcome to another episode of Direct Current. I’m Matt Dozier.

ALLISON LANTERO: And I’m Allison Lantero. We have a great episode for you today. It’s the story of one of the biggest environmental problems of the 20th century and how scientists, policy wonks, and regular people came together to solve it.

DOZIER: We’re gonna find out what happened to acid rain. Here to tell this story, and to find out what we can learn from it, is Producer Pat Adams.


PAT ADAMS:: It’s Fall in the Adirondacks in Upstate New York. The leaves are changing colors, and the water is calm on Big Moose Lake. Covewood Lodge sits right on the edge of it. This place is as quaint and idyllic as you can imagine. There’s a bunch of cabins surrounding a main lodge, all of it built out of pine. It’s ringed by forest and reflected in the shimmering water. Covewood Lodge draws thousands of visitors per year who boat and fish, or just enjoy the peace and quiet of nature.

(DOCUMENTARY CLIP: But there’s something here visitors can’t invisible menace: acid rain.)

ADAMS: That was from an old National Geographic documentary. It was released at a time when acid rain was on the nightly news and debated on Capitol Hill. You don't hear much about it anymore, though. So, what happened to acid rain? To try and understand, I got in touch with someone who remembers it all too well...

DIANE BOWES: This is Diane Bowes, I’m an owner of Covewood Lodge on Big Moose Lake, and I’ve been here for 50-some years.

ADAMS: Diane spoke to me from the top floor of the main lodge, right on the edge of the lake.

BOWES: I live at treetop level and look right out on it. Even though it’s raining at the moment, it’s a beautiful favorite thing to do is to get up in the morning and take a row out on my scull.

ADAMS: The Adirondacks were considered ground zero for acid rain. And people like Diane and her family were among the first to feel its effects, although they didn’t realize it at first.


BOWES: We have a wonderful little hotel that was built between 1925 and 1928, it has old copper pipes, and of course, solder. Then we started getting all these little pinholes through the copper pipes. And that was, you know, annoying and a problem, but we didn’t think much about it.

ADAMS: Until it became personal.

BOWES: was a spring-fed water system...It was wonderful, pure, clear water. Delicious tasting.  You know I can remember one of the girls getting up and saying “gee, it tastes funny.” And then one daughter started having stomach problems.

ADAMS: When doctors conducted blood tests, it turned out Diane’s daughter actually had lead in her system.

BOWES: Well it must have obviously come from the solder in the pipes. So then we started sort of putting 2 and 2, and they started testing the acidity of our spring water, and the spring was very acid. How did this beautiful spring become so acid? And so then they started testing and found that, of course, that the lake was very acid, and we went from there.

ADAMS: Alright, this beautiful lake and crystal spring in the Adirondacks are becoming so acidic that pipes are eroding and the lead in the solder that holds them together is dissolving into drinking water. Not good.


ADAMS: You already know why this is happening, it’s acid rain. But what is it, exactly? To help me understand these impacts better, I called the person who first taught me about acid rain -- my 6th grade science teacher, Mr. R.

(ANSWERING MACHINE: Hi, you have reached Melanie and Tom Robinson. We’re not able to take your call right now, but leave us a message.)

ADAMS: He was busy with his grandkids that day, but I eventually got ahold of him.

TOM ROBINSON: My name is Tom Robinson and I was a schoolteacher for 39 years.

ADAMS: Mr. R, can you explain what’s going on, chemistry-wise, with acid rain? How acidic are we talking?

BOWES:The pH scale goes up to 14, so neutral, or normal, is about 7. You know, normal rain is 5 to 6. Your very acidic levels are down where you lemon juice and vinegar at 2 or 3. And then you get up into base, which is ammonia and lye, and that goes up into 13 and 14. But between 3 and 5, you know, that’s what I found with the lakes up in the Adirondacks, you’re getting almost the acidic levels of vinegar.

ADAMS: Imagine being a fish in that lake...

ROBINSON: And kids understand that. You give them lemon juice and they’ll pierce their lips. Around that level, when it gets to 3 or 4, then you have your fish die.

ADAMS: Not to mention causing lead poisoning in children like Diane’s, harming forests, and eating away at stone, metal and paint.

ROBINSON: It was starting to affect the forest. That took a long time to become evident. For instance the acid rain weakened some of the trees, especially the spruce trees, so they became susceptible to diseases like the spruce budworm. At one point we had lost a lot of our mature spruce trees. Same thing happened with beech trees.

ADAMS: OK, but how did the rain turn into acid? Understanding acid rain begins with understanding one of America's oldest sources of energy generation: coal-fired power plants.

TOM SARKUS: So you have the sulfur in the coal, and combustion is burning the coal in air. And air is 3/4 nitrogen and 1/4 oxygen.

ADAMS: That’s Tom Sarkus. He’s a researcher at the Energy Department’s National Energy Technology Laboratory, which has two main sites in Pittsburgh, Pennsylvania and Morgantown, West Virginia. Coal country.

SARKUS: And the sulfur in the coal...that combines with the oxygen to form SO2.

ADAMS: SO2 is sulfur dioxide. It’s a gas that comes out of the smokestack. Then it gets in the clouds, where it reacts with water vapor to form sulfuric acid.

SARKUS: And you have a similar reaction happening with the NOx.

ADAMS: NOx is scientific shorthand for a family of compounds called nitrous oxides. Those are other gases that are produced by burning coal.

SARKUS: It comes out the chimney also, but instead of forming sulfuric acid it forms nitric acid.

ADAMS: OK, so burning coal creates these two gases, which hitch a ride on some clouds as they blow east. And these gases turn into sulfuric and nitric acid, and then fall as rain. There’s even acid snow and acid sleet...In any case, it eventually ends up in the water supply in places like the Adirondacks.

BOWES: It had to really start in the Adirondacks. Because we were the ones who were first impacted. Then it became known that was also impacting not just the Adirondacks and not just New York State, but also spreading into New England as well.

(CBS TV CLIP: Bugs Bunny and the Road Runner will return after “In the News” and these messages. In the News: Lakes Without Life. New York’s Big Moose Lake is one of hundreds that are dead or dying. Fish and plant life are being killed off by contaminated rain. We’ll be back with “Acid Rain: In the News.”)


ADAMS: By the 1980s,  policymakers started to recognize that acid rain was a serious problem affecting not just Big Moose Lake, but huge swaths of the eastern United States. There were hearings on Capitol Hill to debate what to do. Diane’s husband, C.V. Bowes Jr., came down to Washington DC to testify. Meanwhile, Tom Sarkus and his colleagues were already trying to come up with solutions through their work at the National Energy Technology Laboratory, or NETL.

SARKUS: It’s one of the Department of Energy's 17 National Laboratories. We focus on taking fossil energy and making clean energy from that.

ADAMS: Fossil energy comes from the ground; it’s coal, oil and natural gas. And NETL is one of the world’s leading centers of research into these energy sources and how to make them cleaner.

SARKUS: We conducted a lot of the research in parallel with several years of congressional debate, and we decided to develop a portfolio of technologies that could be applied at power plants of different designs and different configurations. It was quite a comprehensive effort -- it was called the acid rain control R&D program, and we tried to study the problem.

ADAMS: NETL’s solutions to stop acid rain fit into two main categories. You have scrubbers, which attach to a smoke stack and essentially clean sulfur dioxide from the exhaust. And you have measures for when the fuel is being burned that limit the amount of NOx produced in the first place.

SARKUS: Probably in the 1984-5-6 time frame...we had a number of technologies ready to go.

ADAMS: And those technologies were effective. In some cases, they could capture up to 90% of the pollutants causing acid rain. But of course, they weren’t free. Power plant owners weren’t going to just install a costly scrubber out of the goodness of their hearts. There needed to be an economic reason for them to cut down on these pollutants.

(CSPAN CLIP OF PRESIDENT GEORGE H.W. BUSH: Every American expect and deserves to brave clean air and as president it is my mission to guarantee it. For this generation. And for generations to come. Well as we used to say in the Navy. Mission defined mission accomplished. And today I'm very proud, on behalf of everyone here, to sign this clean air bill. The Clean Air Act of 1990. This landmark legislation will reduce air pollution each year by fifty six billion pounds. That's two hundred twenty four pounds for every man, woman, and child in America. And it will go after the three main types of air pollution. Acid rain, smog, and toxic air pollutants. This bill will kind of missions that cause acid rain in half, and permanently cap them at these new levels.)

ADAMS: The amendments to the Clean Air Act established a cap and trade system for the chemicals that cause acid rain. It’s a market-based approach, which lets each power plant decide how to comply, and it provides a financial incentive to lower your emissions. It’s still in effect today.

SARKUS: So the law was passed in 1990, and it set a level of reductions that would begin in 1995. So certainly, we were demonstrating technology in the early 1990s even before the 1995 date kicked in.

ADAMS: And that’s a really important point. Research and development takes years. By the time the law kicked in, technologies were already available, making it a whole lot easier for power companies to comply. NETL and the Department of Energy were ahead of the curve.

ADAMS: In the end, the solution worked. By the end of the decade, 80 percent of coal plants in the country had installed acid rain control devices like scrubbers. Today, we’re preventing 15 million tons of sulfur dioxide and 3-4 million tons of nitrous oxides every year.

BOWES: It’s made a huge difference. We still have pollution, but it’s mostly car pollution. We have different issues, but the pH is wonderful.

ADAMS: The Environmental Protection Agency still monitors acid rain, and if you look at the maps, in 1990 there was a whole lot of red across the eastern United States, indicating urgent levels of acid. Now, most of that has been reduced to acceptable levels, which show up as slightly yellow or green.

BOWES: I have to say, I give my husband credit -- people had the foresight to realize this was a future problem; if we didn’t take care of it now, it’d be an even bigger problem in the future.

ADAMS: So... We did it! We solved the problem of acid rain, using science and policy and the voices of regular people. But...In the last couple decades we’ve learned a lot about a different problem -- one that’s also caused by gases in the atmosphere produced by burning fossil fuels.

SARKUS: The one we're working on today is actually much bigger than acid rain, and that's climate change. 


AL: Up next, Pat takes a look at one tool, one piece of the puzzle, that can help solve the big, unwieldy problem of climate change.


ADAMS: There are a lot of present-day parallels to the acid rain story, so I found an expert to help explain some of them.

CHRIS SMITH: Hi, my name is Christopher Smith, I’m the Assistant Secretary for Fossil Energy here at the Department of Energy.

ADAMS: The Office of Fossil Energy ensures the safety and environmental sustainability of America’s coal, oil and natural gas sources, and aims to reduce the greenhouse gases they produce.

SMITH: About 40% of the electricity that we use -- that we consume here in the United States -- it comes from coal. So as we’re looking at the low-carbon energy sources of the future, we also have to be developing and deploying technologies for the sources that we’re using today.

ADAMS: Now, if you care about climate change, I know what you might be thinking. Why would we be focusing on coal rather than investing in renewable energy technologies? I asked him that.


SMITH: The mission around new renewables is incredibly important. Innovating new technologies based on wind and solar and hydropower and nuclear is going to continue to be important. But at the same time, we have to figure out what to do with the sources of today, significantly because there’s already such an enormous infrastructure in place, and the path to going from what exists now or something new is going to be time consuming.

ADAMS: The reality is that even under the most aggressive climate scenarios, we’re going to be burning fossil fuels for at least a few more decades, according to the Energy Information Administration, a nonpartisan statistical agency. That’s a few more decades we have to make those sources cleaner.

SMITH: And that’s where CCUS comes in. CCUS stands for carbon capture utilization and storage. And the idea is that instead of taking the CO2 that comes out of the back of these plants and goes up into the environment and impacts us in a lot of very negative ways like climate change, you would capture those emissions, compress them, put them in a pipeline, and store them underground.

ADAMS: Remember NETL, the lab that developed the acid rain scrubbers? It’s actually part of the Energy Department’s Office of Fossil Energy. Tom Sarkus and his colleagues have been working on this challenge for a while now, and their work on acid rain helped pave the way.

SARKUS: We're working quite hard and have a moderately robust R&D program on carbon capture and storage technologies. So first we want to capture the CO2 from the power plant -- and this is really where most of the expense is. And there are -- just as with scrubbers and NOX control systems, there are a number of ways of doing that.

ADAMS: This isn’t a fantasy. By October 2016, carbon capture projects had prevented more than 13 million metric tons of CO2 emissions. That sounds like a lot because it is. That’s like avoiding the annual emissions from 2.8 million cars.

The total amount of CO2 emitted by power plants in the U.S. is much greater than that, but the point is that these technologies work -- and they keep getting better. But just like acid rain scrubbers, carbon capture technology isn’t free. The challenge is convincing a power company it’s worth it to invest.

SMITH: And we’re doing this right now in a regulatory environment in which it’s essentially free to emit as much CO2 as you want. So, how can you continue to make the technical and commercial work to push the technologies forward in an environment where companies aren’t compelled to capture the CO2. Again, power companies aren’t charities, they’re for-profit institutions that supply us with energy that we need to carry on with our daily lives.

ADAMS: In 1990, the Clean Air Act amendments gave power companies an economic reason to control the toxic pollutants coming out of their smokestacks.

SMITH: And indeed, before these controls were in place, you would have found a lot of opinions in industry that said it’s simply going to be too difficult, or too expensive or not gonna be realistic to get sulfur and nitrogen oxides down to the levels we see today. But what happens is that when you do have a requirement that’s based on some positive externality, some important public good...

ADAMS: In this case, we’re talking about controlling carbon dioxide emissions to address climate change.

SMITH: ...what happens is that the private sector, together with academia and government, there’s a lot of innovation that occurs. Companies get better at doing this -- you come up with better solutions because there is a direct driver to do so. We think the same thing is going to be the case with carbon capture and sequestration.

ADAMS: The Energy Department doesn’t create laws. That’s up to Congress. But what we can do is find solutions to big challenges like acid rain and climate change before they become even bigger.

SARKUS: One of the things we learned early on that these are complex problems. They're not likely to have a single silver bullet easy answer, so what you need to develop is a portfolio of technologies.

SMITH: If we care about our climate goals, if we care about getting to a world in which we’ve got sustainable levels of greenhouse gas emissions, if you care about reducing climate -- increases of global temperatures to 2 degrees, you have to crack the challenge of how do you reduce greenhouse gas emissions that are coming out of fossil sources. It’s a critical climate mission.

ADAMS: Carbon capture and storage is more than just the pipe dream of a few people at NETL, or the Energy Department. It’s an idea championed by the United Nations Intergovernmental Panel on Climate Change and the International Energy Agency; by nonprofits like the Clean Air Task Force and the Natural Resources Defence Council; and by nonpartisan think tanks like the Bipartisan Policy Center and Third Way. Carbon capture is one piece of solving the climate puzzle. Of course, this puzzle also includes wind and solar; nuclear power and hydropower. It includes electric vehicles and biofuels. It includes lighter materials and more efficient...everything. But as we transition to this low-carbon economy, coal plants are still going to produce tens of millions of tons of carbon dioxide. Now, we have the opportunity to stop it from ever leaving the smokestack.

SMITH: [18:50] We’re gonna need to continue to innovate, to continue to support American researchers and workers and scientists in our effort to make sure that here in the US we’re leading the world in developing these innovations, and in my case, specifically around reducing the cost of carbon capture and sequestration.

ADAMS: That’s why the National Labs are so important. They helped us find solutions to acid rain, and are hard at work today doing the same for climate change.

SMITH: A tremendous amount of great scientists and engineers who are working on this problem -- great, tremendous public servants.

SARKUS: Perhaps I'm biased because I work here, but I'm quite proud of NETL for what we've done and what we continue to do. All the national labs, they're sort of the nation's crown in terms of science, both in terms of people and facilities.  

ADAMS: The point is, the National Labs are always looking for solutions to big, complex problems. And in the cases of acid rain and climate change, they were hard at work before many of us even acknowledged there was an issue. The 17 National Labs are incredible national resources. Our future depends on the innovations they’re able to bring to the world.

BOWES:It is a question not just for our children but our grandchildren.

ADAMS: That’s Diane again, looking out her window on Big Moose Lake.

BOWES: And as we found with the acid rain, it took that long to solve that small problem, I can’t imagine how long it would take to solve the bigger problem of climate change. And if you don’t start somewhere, then you’re lost.

ADAMS: Well the good news is that we’re not lost. We have started somewhere. Some of the nation’s best scientists are improving these technologies everyday. And in the next few months, the first two industrial scale carbon capture facilities will come online. This is just a beginning. but there’s reason to be hopeful.

DOZIER: That wraps it up for this episode of Direct Current. You can learn all about carbon capture and storage and the National Labs on our website,, where you’ll also find plenty of other great stories on science and energy.

LANTERO: And if you have questions about this episode or any other episode you can email us at or tweet @ENERGY. If you’re enjoying Direct Current, help us spread the word! Tell your friends about the show, and leave us a rating or review on iTunes. We appreciate the feedback.

DOZIER: We’d like to give a big thank-you to Diane Bowes at Covewood Lodge.

LANTERO: Thanks to Tom Sarkus and Dave Anna from the National Energy Technology Laboratory, and Chris Smith from the Energy Department’s Office of Fossil Energy.

ADAMS: And thanks, of course, to my 6th grade science teacher Tom Robinson, and Arlene Balkansky from the Library of Congress.

LANTERO: Direct Current is produced by Matt Dozier, Simon Edelman and me, Allison Lantero. With Producer Pat Adams, Art and design by Cort Kreer. Support from Paul Lester, Daniel Wood, Atiq Warraich and Ernie Ambrose. And special thanks to our boss, Marissa Newhall.

DOZIER: Thanks to Bridget Bartol, Eben Burnham-Snyder and the Energy Public Affairs Team. We’re a production of the Department of Energy and published from our nation’s capitol in Washington, D.C.

LANTERO: Until next time, thanks for listening!






Listen to the podcast, then check out these resources to learn more.

Acid Rain

Carbon Capture

The National Labs