The EPA Rule on Ozone Levels Recently, the US Environmental Protection Agency (the “EPA”) published an administrative rule that requires states to lower atmospheric ozone levels to 60-70 parts per billion. For states in the Intermountain West, where the level of naturally occurring ozone (or “background concentrations”) routinely reaches 60 – 75 ppb, it’s going to be tough to comply. According to National Oceanic and Atmospheric Administration-led research, it’s not a problem limited to inversion prone valleys like Salt Lake and Cache. “We expected we were going to see intrusions big enough, individual events, which would…