These cities are blessed with sea-breezes that blow away pollution, noted Forbes. But they "are also reaping the rewards of investing in efforts to keep clean, even as their populations boom."
Forbes made air quality a big factor in its ranking. To determine the cleanest major cities in the United States, Forbes initially measured the rankings for air pollution and ozone levels among all 49 U.S. metro areas with populations exceeding 1 million, using data from the American Lung Association. Forbes then measured the cities on additional but less-weighted factors of water quality and per-capita spending on Superfund site cleanup and solid-waste management.
Seattle spends more on waste-management per capita than any other major city, Forbes determined.
Water cleanliness rankings were derived from statistics compiled by the University of Cincinnati from local reports of EPA violations. Metros were ranked based on reports of bacteria, chlorine byproducts and chemicals or metals such as arsenic, copper and lead in the drinking water.
[[In-content Ad]]