Denver Makes Headway Against Its 'Brown Cloud'
As antipollution measures take effect, city records second straight year with no federal air-quality standard violations.
For more than a decade, residents of the Mile High City have had to make smog forecasts a part of their daily planning - in ways as simple as whether they stoke up the fireplace or take a car to work.Skip to next paragraph
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But as pressure to cut down on Denver's chronic pollution problem mounts, the city is making significant strides toward cleaning up its air. The number of "red" days - when residents are prohibited from burning wood and encouraged to take a bus or carpool - are declining, and for the second year in a row, Denver hasn't violated a single federal standard for air quality.
"It's a tremendous change from 20 years - and even 10 years - ago," says Theresa Donahue, manager of the city's department of Environmental Health. "We're very pleased about that."
Considering this city's pollution history, it's an impressive feat. In the 1970s, Denver air exceeded federal limits for carbon monoxide and particulates virtually every day during the high-pollution winter season. And as recently as a decade ago, there were violations of federal air-quality standards every week.
Denver's strides in air quality in fact underscore a nationwide trend. Thanks largely to tougher federal regulations and cleaner-burning automobiles, air quality across the country is improving dramatically, says Christine Sansavero, an air-quality policy analyst at the Environmental Protection Agency (EPA) in Durham, N.C. "In the United States, we've reduced emissions of air toxins by more than 1 billion pounds since 1990. Overall, the air is much cleaner in all metropolitan areas in the US. Even the areas that are not considered clean are cleaner than they were a decade ago."
Los Angeles is a prime example: While maintaining its notoriety for having the dirtiest air in the country, this past year the City of Angels had the smallest number of ozone violations and health advisories in decades.
Automotive technology deserves its share of credit for reducing exhaust emissions throughout the nation. On average, vehicles today burn 95 percent cleaner than they did in the 1970s, when the EPA started enforcing the Clean Air Act. And 1990 amendments to the act, which tightened emissions standards for industry, notched a deeper dent into the quantity of air pollutants released.
But Colorado officials figured out a decade ago that it would take more than advancements from Detroit and federal regulations to clear the high-altitude smog in Denver.
In addition, combating the notorious "brown cloud" that shrouds the city - and tinges the snow-capped Rockies with a shade resembling cafe latte - was deemed as much a matter of economics as health. If Colorado was to continue to lure businesses and tourism to the state's natural splendor, the mountains had better be visible. And the air had better not be.
To that end, Colorado launched an aggressive air-quality improvement campaign in the mid-1980s, and hasn't let up since. Throughout the winter high-pollution season, which spans from Nov. 1 until March 31, all gasoline sold here must be "oxygenated" - meaning it contains additives to reduce carbon-monoxide emissions. The region also has one of the strictest auto-emissions testing programs in the country.