Change to Clean Water Act Would Have Repercussions, Even in the Arid West

TONTO NATIONAL FOREST – Nathan Rees and Beau, his German shorthaired pointer, took this reporter off-trail to hike along Dude Creek in Tonto National Forest, northeast of Phoenix. We were looking for an ephemeral stream: a channel that may be dry now but clearly carries water occasionally.

We found one.

“(It’s) probably not mapped (because of) how small it is,” Rees said as Beau explores the banks of Dude Creek. “But this contributes to Dude Creek that we’re standing in right now that has water in it.”

Rees works for the Arizona chapter of Trout Unlimited, the sportsman’s group. It favors federal protection over ephemeral streams, so industries would need a certain federal permit to build around them or discharge anything into them.

Trout Unlimited says three-quarters of Arizona’s streams are classified as ephemeral, which in legal terms means waterways that flow in response to precipitation.

“If there was a mining operation even a mile upstream from where the confluence is, and tailings are being dumped into this, you know, dry washbed, when those heavy rains come, it’s going to push all those tailings downstream,” Rees warned.

“It’s going to get pushed out into Dude Creek, which is going to go into the East Verde, into the Verde, into the Salt, down to the Phoenix valley.”

Big Arizona waterways like the Salt River fall under the federal Clean Water Act, as do some of their tributaries. But exactly which tributaries are covered by the act has led to many legal fights since it was passed in 1972.

Earlier this year, the Environmental Protection Agency and the Army Corps of Engineers said ephemeral streams do not fall under federal jurisdiction under the Clean Water Act. The proposed change would be from rules finalized by those same agencies in 2015 under the Obama administration. The public comment period on the change ends Monday.

“The hook is ‘Waters of the United States.’ Those are the jurisdictional waters,” said Bethany Sullivan, a law professor at the University of Arizona. “Well, what does that mean? That definition has evolved tremendously over time.”

Sullivan said the Clean Water Act has a long and complicated history. The Obama rules came after a Supreme Court case from 2006 left no clear directive, giving each side of the issue a legal argument to make. After studying the issue, the Obama-era EPA and Army Corps of Engineers went with what Justice Anthony Kennedy had written in a separate opinion.

“The idea that waters that have a ‘significant nexus’ with traditionally navigable waters should fall within the scope of the act,” Sullivan said.

One example would be a wetland or desert wash whose hydrology significantly affected a more permanent waterway, even if the surface water in those wetlands or washes did not physically touch the main waterway.

The Obama administration rule is unpopular with mining and development companies.

Adam Hawkins, who consults for mining companies with the firm Global External Relations, said the 2015 rule only added “additional, unnecessary time and analysis to the process with, in my opinion, no additional protection to the environment” because other environmental laws also are in effect.

EPA and Army Corps of Engineers officials under President Donald Trump are using a different, narrower definition of Waters of the U.S., this one from Justice Antonin Scalia. Ephemeral streams would not be covered under the current proposal.

Spencer Kamps, with the Home Builders Association of Central Arizona, is happy with the proposed revision.

“The purpose and goal of the Clean Water Act was to protect water,” he said. “If water doesn’t remain there, (what) is the need for a federal footprint to regulate that system?”

Getting a federal permit under the Clean Water Act, Kamps said, can cost hundreds of thousands of dollars in engineering and legal services. And he added that having less federal oversight does not mean no oversight. In other words, the state can step in.

After early signs the Trump administration would change the rule, Arizona Gov. Doug Ducey wrote to the EPA and said the state would have to “evaluate how to protect waters that no longer fall under the Clean Water Act.”

The state is still finishing its comments on the proposed change, and the Department of Environmental Quality declined an interview.

Melinda Kassen, an attorney with the Theodore Roosevelt Conservation Partnership, a sportsman group out of Colorado, does not see states filling the breach left by the federal government. She argued state Legislatures will be reluctant to pass any fee increases needed to improve regulation.

“We have the Clean Water Act, in part, because the states had the authority to do this before and they weren’t getting the job done and the Cuyahoga River burned and other things happened,” she said. The Cuyahoga River in northeastern Ohio famously caught fire in the late 1960s, precipitating the Clean Water Act.

Kassen also sees the Trump EPA as going further than a rollback of Obama administration rules in saying interstate waters – those that flow in two or more states – are not automatically considered under federal jurisdiction.

“It’s a rollback of fundamental principles that have been on the books, in place, enforced, implemented since 1972,” she said.

Study: Arizona has Longest Clean Water Permit Wait Times in Southwest

PHOENIX — Receiving a decision on a construction permit under section 404 of the Clean Water Act takes longer in Arizona than in any other Southwestern state, a new study found.

Before construction can begin on almost anything — from a highway to a housing development — companies and states have to receive a 404 permit from the U.S. Army Corps of Engineers and the U.S. Environmental Protection Agency. It’s a provision under the Clean Water Act to track what contaminants are ending up in America’s waterways in what amounts.

The University of California study looked at 404 permits for projects submitted in Arizona, California, Colorado, New Mexico, Nevada, Texas and Utah.

“I would have expected California would have been the slowest state because California has a lot more environmental regulations,” said researcher Nícola Ulibarrí.

However a project in Arizona takes about 67 percent longer to receive a permit decision from the Army Corps of Engineers, who processes the permit before it’s approved or declined by the EPA.

Ulibarrí said the difference was a mystery even though her study accounted for type of project, population density and income.

“The U.S. Army Corps of Engineers is aware of the study but does not comment on studies where USACE has not been involved in the study process,” said a spokesperson in an email.

Ulibarrí said that, while regulations are important to protect human health and the environment, long wait times increase costs for businesses and taxpayers.

“If they are driving on roads or are drinking water or are buying into a new housing development, all of those things take 404 permits, so if it takes longer to permit the process, then that’s going to drive up the overall cost of the project,” she said.

There are changes coming to the system. In 2017, the Arizona state legislature passed a bill that would transfer permitting from the U.S. Army Corps of Engineers to the Arizona Department of Environmental Quality.

AZDEQ is currently conducting stakeholder meetings and expects to submit their full implementation plan to the EPA by May of 2020.

Arizona Adopts First Rules to Encourage Electric Vehicles

PHOENIX – Tesla recently announced major layoffs across all its operations, hoping to cut costs and price its electric vehicles to be more competitive with gasoline-powered vehicles. The move came after the Trump administration pledged to end Obama-era federal tax credits for electric vehicles of up to $7,500.

Some states have policies to subsidize and encourage electric vehicle use, but Arizona only recently has taken its first steps in that direction. The transition to EVs will require major investments in incentives and infrastructure, but the price could actually be less than the environmental and health costs of the status quo.

Europe on Track

Outside the U.S., electrification technologies are more widespread and accepted, and not just in passenger cars. At Formula E races across Europe, electric cars compete for coveted international titles. There are 22 cars from nine manufacturers on the FIA-sanctioned circuit, all powered by electric motors that can propel the cars to nearly 150 mph.

ON Semiconductor of Phoenix designs and manufactures the computer chips used in these racing motors, whose whine sounds a lot like a blender with a missing blade. ON also designed chips for Tesla to develop its pilot technology.

“We’re now entering season five of Formula E racing, which is taking the race cars and electrifying them. So now it’s going from a combustion engine that’s burning gas into a battery-powered vehicle,” said David Somo, senior vice president of strategy and marketing for ON.

Racing Formula E in Europe was a natural fit for the technology, he said. Europe has enacted several environmental policies that support alternative fuels designed to reduce greenhouse gas emissions, Somo said. In the U.S., electricity is considered an alternative fuel under the Energy Policy Act of 1992.

It’s not like Americans aren’t buying EVs. According to Green Tech Media, 2018 was a record year for electric vehicles, with 361,307 units sold. But electrics still represent a small fraction of vehicles on U.S. roads.

“Americans are buying SUVs and light duty trucks at a much, much higher rate, where last year we sold a little less than half a million electric vehicles. We sold over 10 million SUVs and light duty trucks,” said Paul Lewis, vice president of policy at the ENO Center for Transportation, a Washington, D.C., nonprofit think-tank focused on transportation issues.

“Transportation has been particularly difficult to decarbonize. And in fact, vehicle-miles traveled is growing, and so are the emissions related to transportation. So we have a huge environmental challenge in front of us related to transportation.

“Having everybody drive alone in their own cars is becoming untenable and not workable in a modern economy where you need to have densities and you have lots of people being very productive working closely together. And that’s where we have to kind of think more holistically about our transportation system.”

Tourism and population growth

It’s a particular challenge for a state whose top industry is tourism.

That means as a growing number of travelers come to Arizona, more cars will be on the road. That will be in addition to the increasing number of drivers added as more people continue to move to Maricopa County each year.

“The effects of climate change are here now,” said Dan Lashof, the U.S. director of the World Resources Institute, a D.C. nonprofit that researches sustainability issues. “We have a very short window of opportunity to really transform the way we produce and consume energy, eliminate emissions of heat-trapping pollution into the atmosphere.”

At one time, Arizona drew people seeking relief from respiratory problems. Now, Maricopa County receives a grade of “F” almost every year from the American Lung Association’s “State of the Air” report. Phoenix ranks as the eighth most polluted city in the country, measured by ozone level.

Ryan Cornell of Phoenix drives a Tesla Model 3, the latest of several electric cars he has owned. Yes, the car was expensive – prices start at more than $45,000 – but he sees it as an investment.

“Whether it’s five years, 10 years or sometime beyond that, we need to go to 100 percent, and we need to go to 100 percent renewable energy,” said Cornell, whose master’s thesis at Harvard Extension School compared the costs of EVs with the those of vehicles powered by internal combustible engines.

“Clean air is clean air. A liveable climate is a liveable climate. And I think people forget, too, that … the EPA was founded by (President Richard) Nixon. There’s no reason that everybody can’t be on board with some of these policies.

“We can’t tell someone who has health problems related to pollution, ‘Well, that’s a fake cost, that’s not a real cost.’ Like, that’s just as real as paying for car insurance or your monthly payment on the car or your electric bill.”

In December, the Arizona Corporation Commission adopted new policies to encourage Arizonans to switch to electric vehicles and utilities to invest in infrastructure to support it.

“Because of the nature of the power that electric vehicles are going to use, you have to be ahead and start developing programs and policies and tell utilities to prepare for it,” Commissioner Boyd Dunn said.

“Now, some are already doing that. The Salt River Project, that we don’t regulate, is already out there promoting electric vehicles … locating charging stations on their infrastructure. I know APS (the state’s largest power provider) has a program already, but they’re small.”

Dunn also noted the economic advantages EVs could bring to the state, such as the Lucid Motors plant planned for Casa Grande.

“We want to encourage the electric vehicle industry to locate in Arizona,” he said.

The commission received several letters objecting to the new policies.

“And I’ve heard from individuals who say, ‘Well, I don’t intend to have an electric vehicle. I don’t want to be paying a subsidy to let others have electric vehicles,’” Dunn said.

Electric cars are expensive, and building infrastructure to support those cars comes at a high cost – one residents may not be willing to pay. But at what cost to human health and the environment?

LA Metro’s Idea of Solving Traffic: Making You Pay for It

LOS ANGELES — Good news, drivers. Metro is looking into the one solution that has actually been proven to reduce traffic.

Los Angeles County’s transit agency is set to vote this week to study a practice called “congestion pricing,” which would charge people to drive on roads based on how busy it gets.

Metro CEO Phil Washington proposed the idea last month as a way to not only reduce impassable roads, but accelerate some big transportation projects for the 2028 Olympics.

“We have to do something about congestion in the county and it’s going to get worse,” Washington told KPCC’s AirTalk in December.

HOW DOES CONGESTION PRICING WORK?

If you’ve ever been hit with surge pricing while using a ride-hail service like Uber or Lyft, or tried the express toll lanes on the 10 or 110 freeways, you get the gist of congestion pricing. Users get charged a fee that goes up or down based on demand for a limited commodity, in this case the roads.

Metro is looking at three distinct models for congestion pricing:

  • The first, cordon pricing, is the most common in practice. It sets a variable fee to enter a certain neighborhood, usually the central business district, as is done in London and Stockholm.
  • The second model charges drivers based on the number of miles they travel, with rates dependent on the time of day and where the travel occurred.
  • Under the third model, drivers are charged on certain busy corridors, like freeways or big arterials, such as Wilshire Boulevard.

In all cases, the fee would vary according to the size of the demand. Driving at 8:30 a.m. would cost much more than at 10:30 p.m.

The idea is to force people to consider whether they really need to travel into a crowded area or at a peak time, or whether they might travel at a different time or elsewhere, or use a less costly alternative mode of transportation.

WHY ARE EXPERTS SO HOT ON CONGESTION PRICING?

“The reason that people like me and my colleagues like congestion pricing so much is that it really is the only way to meaningfully reduce traffic congestion,” said Michael Manville, UCLA urban planning professor, at a Metro committee meeting in January.

“Conceptually, it’s the only way to do it. Empirically, it’s the only policy that’s ever been shown to reduce congestion and keep it reduced,” said Manville, pointing to successful programs in London, Stockholm, Milan and Singapore.

In London, the number of private cars entering the congestion zone dropped by 39 percent between 2002 and 2014. In Stockholm, traffic dropped by 20 percent during the 2006 pilot program, enough to convince a skeptical public to vote and make the charge permanent.

New York City has been working on some form of congestion pricing for years.

Manville also pointed to evidence that efforts to expand road capacity, by building more or bigger freeways or taking some cars off the road by building trains, don’t permanently reduce traffic. In most cases, these increase it.

“What basically happens is that you can have a situation where suddenly the road’s moving faster, but pretty soon people realize that, and they start to converge on the road at that time,” said Manville.

(Kevork Djansezian/Getty Images)

It’s such a well-documented phenomenon that it has a name: the Fundamental Law of Road Congestion — and we’ve written about it here.

Congestion pricing operates on basic economic theory. If there’s a high demand for a commodity and you give it away, people will get in line to get it and “pay” with their time instead. Soviet bread lines or free ice cream cones show how this plays out.

But if you set the price of a commodity correctly, you can mitigate the demand for it, and in the case of the roads, make them function more efficiently.

Many people are understandably resistant to the idea of paying for something they currently get for free. Until now, it’s been pretty difficult for congestion pricing to get political traction in the U.S., or be taken seriously by decision-makers.

DON’T WE ALREADY PAY FOR THE ROADS?

Theoretically, yes. Gas taxes are intended as user fees that pay for the construction of roads, although technically our gas taxes haven’t actually paid for the roads in quite some time.

In Los Angeles County, residents also pay higher sales taxes to fund transportation, thanks to four voter transportation tax measures approved in recent years.

Manville said we could think of congestion pricing as metering road use, the way we meter the use of services like electricity or water. Once the pipe system or the electric grid is built and paid for, utilities don’t stop charging people to use the service. If they did, people would leave their water on for 10 hours or run their air conditioners all day.

“One thing that price does that the gas tax does not do is not just make sure that the service is there but that it’s good service,” he said.

Under Manville’s analogy, the roads are like the water service. We only have enough of it to allocate well, and it’s only allocated well if it’s priced right.

AREN’T THERE PRIVACY CONCERNS?

A cordon or corridor system would likely require all cars to carry a transponder, such as the FasTrak currently used for the express lanes. A charge based on vehicle miles traveled could be viewed as more invasive, requiring some kind of location-enabled tracking that plugs into a car’s computer.

Metro has already had a hard time enforcing tolls in its express lanes, admitting a full quarter of users evade payment by switching their transponders to carpool or avoiding transponder readers. Metro is pursuing video systems that can read the number of passengers to catch carpool cheaters.

WON’T CONGESTION PRICING HURT POOR PEOPLE?

This is an oft-cited criticism. The fact is the charges would disproportionately burden lower-income people.

Manville pointed out that we accept many other regressive charges, such as those for utility bills, gas taxes and transit sales taxes but that there are many ways to mitigate the negative effects for disadvantaged populations. Offering a low-income discount, as Metro does for transit fares, is one.

The revenues from congestion pricing can also be reinvested into alternative modes of transportation like transit to make non-auto travel more viable. And with reduced traffic, buses can operate much more efficiently.

Metro’s Washington has even suggested that county transit could be offered free with revenues from congestion pricing. Metro estimates congestion pricing could raise about $10 billion a year.

“If we were to implement something like this, we would be the first major city in the world that would offer free transit on the scale that we have it here in Los Angeles,” he said.

From neon orange to chocolate brown: The West’s unluckiest river takes a beating

DURANGO, Colo. – In early August 2015, Barb Horn stood on a bank of the Animas River, waiting for mine waste spilled upstream to reach the city. She and hundreds of others waited hours for the waste plume to appear, but darkness fell.

The next morning, she saw the change.

“It was absolutely surreal,” Horn said. “And I think that’s why it went viral. It’s like somebody Photoshopped the river orange.”

Upstream, Environmental Protection Agency workers and an environmental contractor cleaning up the Gold King mine near Silverton had accidentally triggered the spill of 3 million gallons of rust-colored waste, known as “acid mine drainage.”

“If you’re a Harry Potter fan, it looked like butterbeer, like butterscotch,” said Horn, a water quality specialist with Colorado Parks and Wildlife. The water was laden with metals, including iron, which colored the water reddish-orange.

The Animas begins in Colorado’s San Juan Mountains before joining the San Juan River, an important tributary of the Colorado River.

For Horn, the spill was a stark visual reminder of the river’s long history of pollution from abandoned mines.

“And it immediately tugged on your heartstrings thinking nothing could live in that,” she said.

Barb Horn, a water quality specialist for Colorado Parks and Wildlife, says ash from this summer’s 416 Fire was deadlier than acid mine drainage from the 2015 Gold King Mine spill. (Photo: Luke Runyon/KUNC)

The spill temporarily stopped recreation in the river and forced farmers to delay irrigation to their crops. But life in the river? It didn’t change much. The bugs and fish survived and showed no signs of short-term harm. The fish had been living with heavy mineralization of the water for decades.

Crisis averted — until this year.

“So I joke that now the river looks like Willy Wonka and the Chocolate Factory’s chocolate fudge river,” Horn said.

We spoke along the river’s stretch through the city. The water was a cloudy brown color with suspended bits of charred debris.

The first few ash-laden runoff events probably killed 100 percent of the fish in a 30-mile stretch of the Animas.

The Animas began the summer with record low water because of long term drought and a warm winter. That primed the nearby mountains for wildfire. The 416 Fire ended up burning about 55,000 acres around the drainage basin for Hermosa Creek, a tributary of the Animas. When rains fall on the burn area, a thick sludge washes into the river.

Horn says official surveys haven’t been conducted, but it’s likely the first few ash-laden runoff events killed 100 percent of the fish in a 30-mile stretch of the river.

“You could literally see the fish coming to the banks gasping for air. It physically smothered their gills and their ability to breathe,” Horn said. “So there it was, it didn’t look as bad. It came from a, you could argue, natural source and did way more damage.”


Sediment and ash from the 416 Fire piles up along the banks of Hermosa Creek, a tributary of the Animas River. (Photo: Luke Runyon/KUNC)

Many Western rivers are stressed by drought, pollution, overuse by cities and farmers and runoff from wildfires. The Animas is the perfect poster child.

“It certainly is unlucky,” said Scott Roberts, a researcher with the Mountain Studies Institute, a nonprofit research group based in nearby Silverton. “It’s unlucky now. And it’s been unlucky for throughout time really.”

The river is facing problems that show themselves, including a vibrant orange smear or a chocolate brown sludge, he said. Or like earlier this summer, when the river all but disappeared within Durango’s city limits, recording its record lowest flow in 107 years of data.

But there are many other issues that don’t draw public attention. Before the Gold King Mine spill, and even now, the river receives acidic water laden with heavy metals from the region’s numerous abandoned mines. Adding insult to injury, in July 2018 a truck carrying waste material from the mine site crashed into Cement Creek, another Animas tributary.

“It’s being stressed by drought, being stressed by warmer temperatures,” Roberts said of the Animas. “It’s being stressed by runoff from wildfires, being stressed by elevated metal concentrations, being stressed by bacteria, by nutrients.”

Roberts points to studies that showed samples of the river’s water with high levels of bacteria commonly found in humans, likely leached from underground septic tanks.

Tom Knopick is co-owner of Duranglers, a fly-fishing outfitter. He predicts the Animas River “will be in a short period of time better than it was before the fire.” (Photo: Luke Runyon/KUNC)

“I don’t think the problems that are plaguing the Animas today are unique to the Animas,” said Ty Churchwell of Trout Unlimited, based in Durango. Trout Unlimited receives funding from the Walton Family Foundation, which also provides funding for KUNC’s Colorado River coverage.

In fact, Churchwell said, drought, ash-laden runoff and mine pollution are often the norm in Western watersheds. The Animas has just experienced the extremes of all three in a short period of time.

“We certainly have experienced more than our fair share of traumatic incidents here in the last three years,” he said.

All these stressors don’t make it easy on local business owners, heavily dependent on tourists coming to town to raft and fish on the Animas. Low flows have curtailed river rafting operations throughout the Southwest.

Fishing isn’t restricted on the river through Durango, but local anglers are avoiding large portions of the stressed river this summer, said Tom Knopick, co-owner of Duranglers, a fly shop in downtown Durango.

He takes solace in knowing that all this trauma is bringing attention to the Animas’ myriad problems. Some of the mine waste is being treated now before draining into the river. When it comes to the fire-related sludge, the healing process has already begun.

“We’ve seen this before and we know that we know that it’s a short term problem,” Knopick said, comparing this summer to that of 2002 when the Missionary Ridge fire scorched more than 70,000 acres outside Durango. “You know we don’t like it. Rather not be dealing with it. But the reality is the Animas will be in a short period of time better than it was before the fire.”

But it could be another five to 10 years before the Animas is back to its former self, according to Horn of Colorado Parks and Wildlife.

“Rivers really are a great metaphor for our body and our own health and our own lives,” she said. “You can think about maybe the Animas is having a heart attack, a stroke and clogging up and saying we need to pay attention to what we eat or what we’re doing with her and to her.”

Horn said rivers have been rebounding from cyclical drought and fires for millenia. But human activity has made the frequency, duration and magnitude of those events worse.

This story is part of a project covering the Colorado River, produced by KUNC and supported through a Walton Family Foundation grant. KUNC is solely responsible for its editorial content.

Think you can escape pollution by going to a national park? Think again

LOS ANGELES – Mountains. Forests. Starry nights. Smog? Sadly, yes: The air in two popular national parks in California is as dirty as it is in Los Angeles — the smoggiest city in the country.

“When you think of national parks, you think of these as being really pristine areas, almost areas you want to go to get out of cities,” said David Keiser, an economist at Iowa State University, who co-authored new research, published Wednesday in Science Advances

“But in many ways, the airquality conditions are just the same there as they are in cities today.”

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The dirt on dirty air

From 1993 to 2014, Los Angeles racked up 2,443 days in which air quality was so bad it violated federal safety standards for smog, also called ground-level ozone.

But Sequoia and Kings Canyon National Parks – a wonderland of rocky cliffs, icy mountain lakes and gigantic trees just east of Fresno – had even more smoggy days: 2,739.

Joshua Tree National Park was almost as bad, with 2,301 days.

“It’s a common misperception that because a place is labeled as a national park, there’s boundaries erected around it that prevent air pollution,” said Stephanie Kodish, head of the clean-air and climate program at the National Parks Conservation Association. There aren’t.

Where the pollution comes from

Both parks are downwind of the most air-polluted area in the country:

In Joshua Tree, the pollution blows in all the way from the Los Angeles Basin.

In Sequoia and Kings Canyon, it comes from big farms in the Central Valley and cities like Bakersfield, Fresno and the San Francisco Bay Area.

Smog – ground-level ozone and airborne particulates – forms when sunlight reacts with a volatile organic compound and nitrogen oxide from vehicle exhaust, power plants and factories. Volatile organic compounds are common in household products and fuels.

But in cities, air quality improves overnight. It doesn’t as much in nature, according to Annie Esperanza, the air-resources specialist for Sequoia and Kings Canyon National Parks.

In urban areas during the day, nitrogen-oxide emissions contribute to smog. But at night, with the absence of sunlight, nitrogen oxide switches sides to help break down ozone, so that by morning, the air is cleaner.

But in national parks and other less-populated areas, there aren’t as many sources of nitrogen oxide around at night to break down the ozone. That’s because there are fewer people driving, so smog lingers day and night.

For healthy adults, high levels of ozone can make it hard to breathe, cause wheezing or respiratory infections.

One study found that breathing smoggy air for a day or two increased the risk of heart attacks for middle-aged adults without heart disease. And many studies have found hospital visits for heart and lung problems go up on days when air pollution is bad.

It’s even worse for kids and the elderly.

Fading from view

Beyond the health effects, smoggy days in national parks are just a bummer because they make it harder to see the epic vistas visitors came for.

Esperanza says on a clear day, you should be able to see more than 100 miles from an overlook on Sequoia and Kings Canyon’s steep, winding entrance road.

“When visibility is obscured, you can maybe see 25 to 30 miles,” she said.

Know before you go

The parks with the worst air quality try to warn visitors about air quality through Twitter handles, such as @SequoiaKingsAir.

You can also check air quality here. Just enter the name of the park you want to to visit, or click on it on the map, and real-time air-quality data will pop up.

These warnings may be working, because the researchers found that fewer people visit parks on smoggy days.

“It turns out a 1 percent increase in ozone levels results in a 1 percent decrease in visitation,” Keiser said.

Is the air quality improving in national parks?

Yes, but not as quickly as in other places.

Since the early 1990s, LA and other cities have made huge gains in cleaning up the air. But air pollution in national parks remains stubbornly bad.

Keiser, the Iowa State researcher, and his co-authors found that between 1993 and 2014, the average number of bad air days in U.S. cities fell from 53 to 18 days a year. Meanwhile, the number of smoggy days in national parks didn’t fall as much: from 27 in 1993 to 16 in 2014.

That means, as of 2014, national parks were nearly as smoggy as U.S. cities.

Part of the reason for the slower progress in national parks is that, for a long time, regulatory agencies weren’t focused on parks. A 1999 EPA regulation called the Regional Haze Program requires states to clean up the air in national parks, but it didn’t take effect until 2007, so there just hasn’t been as much time for things to improve.

“You have a longer history of targeting sources of pollution that have an effect on public health,” Kodish said. “It’s more recent that there have been targeted efforts to clean up pollution that’s harming parks.”

In other words, things that improve air quality for people living in cities – like forcing big emitters such as refineries to install modern pollution controls – may not work for the rural places where smog gets carried.

Ozone pollution bad in cities all over West

PHOENIX – The nearly 250 employees who work at Coreslab Structures could have looked up one June morning to see a yellow flag flying on top of their building. It was a signal to the employees, who often work outside, that the air quality that day was acceptable but possibly concerning to those with chronic health problems.

Coreslab, which produces precast-concrete construction materials in southwest Phoenix and 17 other sites in North America, became the first business in Arizona to join the state’s Air Quality Flag Program. More than 200 schools are part of the program, which is open to everyone.

“To me, it kind of seemed like a no brainer,” said Brandon Dickerson, plant safety coordinator at Coreslab. “Everything we do here in the production yard is completely outside.”

The Arizona Department of Environmental Quality established the Air Quality Flag Program in 2007 to alert the public to high-pollution advisories. Based on the Environmental Protection Agency’s Air Quality Index, there are four colors: red, orange, yellow and green.

“Red, for instance, means we are over a federal health-based standard,” said Timothy Franquist, air-quality director at ADEQ. “Green means that we are in good for the air quality for the day.”

In 2017, Phoenix had 42 days in which ozone levels exceeded the EPA’s recommended limit, which would signal a red or orange flag, according to the ADEQ.

The American Lung Association in April listed the Phoenix area as the eighth most polluted city in the country.

And when it comes to air pollution from ozone, cities in California and Arizona topped the list.

The Arizona Department of Environmental Quality’s Timothy Franquist said certain groups – including people with asthma or other respiratory diseases, children and elderly people – are sensitive to higher ozone levels and particulates.

Individuals who enjoy activities outdoors also are susceptible to the risks of poor air quality.

“We just want to let those community members know what the air quality is like that day so they can take the proper precautions to either limit their exposure or maybe go out at different times of the day,” Franquist said.

In Arizona, most participants in the flag program are schools because children tend to be the most sensitive population, Franquist said.

“The real key to this is this is a voluntary program,” Franquist said. “We have over 200 schools, but it’s open to everybody – businesses, government agencies – the more people that participate, the more we can get the message out to the residents of Arizona.”