Ozone troublemakers in north metro: Chatfield State Park, Rocky Flats, Fort Collins

"Denver has struggled with ozone levels for thirty years, and the fight isn't over yet," in this week's print edition, takes into account the national standard as applied to each site in the area. Three of them are operating at levels above the healthy rate.

According to the Environmental Protection Agency's most recent ruling, the acceptable health standard for ozone in the environment is 75 parts per billion. The pollutant, which is fine up high but ominous at ground level, is a reaction between volatile organic compounds and oxides of nitrogen that have been known to damage lungs, particularly in children, the elderly and those with pre-existing lung conditions.

In the state's Denver Northern Front Range area, the only one with established problems pertaining to ozone or any of the other pollutants monitored by the EPA, ozone levels are measured in a set of sixteen stations. Once collected, readings are uploaded to the Colorado Department of Environment's website hourly, but not every reading is key.

Ozone levels are measured and averaged over an eight-hour span and then compared across three years of data -- and for reasons that don't matter as much as they should, it is the fourth highest number from each site that makes the difference. In the Denver area, three sites are currently nonattainment for ozone levels higher than 75 ppb. The air quality troublemakers are: Chatfield State Park (at 77), Rocky Flats North (at 78) and Fort Collins West (at 76). Three other sites hover just below the minimum at 74 parts per billion.

Curious about how your side of town fares? Look below to check out the most recent charts of the maximum numbers for the current three-year period.

More from our archive: "Colorado's 300 days of sunshine claim: It's a myth, and state's climatologist tells us why."