EPA ozone standards

Limit prior to 2008: .08 parts per million

New limit set in 2008: .075 parts per million

New limit pending in 2010: Between .06 and .07 parts per million

How WNC stacks up

Ozone levels have improved gradually in WNC over the past 10 years. They can vary widely from year to year depending on weather, however. Wetter and cooler summers see fewer bad ozone days that hotter, drier ones.

To determine whether WNC meets the new ozone limits, an average of three years worth of ozone readings — from 2008 through 2010 — will be used.

Here’s the levels for ozone monitoring stations in the region based on the three-year average from 2007-2009. Ozone is worse at higher elevations and surprisingly consistant across the mountains.

Waynesville    .068 parts per million

Bryson City    .064 parts per million

Asheville    .069 parts per million

 

High elevation sites

Purchase Knob    .074 parts per million

(near Hemphill Knob above Jonathan Creek in Haywood County)

Frying Pan    .074 parts per million

(near Mount Pisgah off the Blue Ridge Parkway in Haywood County)

Mount Mitchell    .074 parts per million

(highest elevation on the east coast)

• A monitoring station has been recently installed on Barnet Knob on Cherokee Indian Reservation and will be providing data this year.

Reading Room

  • A strange mix of books crosses my desk
    A strange mix of books crosses my desk The first weeks of 2018 have seen some offbeat books shamble across my desk and into my fingers. First up is John Buchan’s Mr. Standfast, also known as Mr. Steadfast. Buchan, a Scottish novelist and politician who served as Governor General of Canada from 1935…
    Read more...
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