"Colorado officials say it will be 2021 before the state meets the current federal health standard for ozone air pollution — for which metro Denver and the northern Front Range have been out of compliance for more than four years.

The state air quality control commissioners last week put forth a plan to meet an old standard — 75 parts per billion of ozone, set in 2008 — by relying on existing initiatives to shut coal-fired power plants, enforce controls on the oil and gas industry and shift to cleaner vehicles.

They aim to meet that old standard by 2018 and seek federal approval, to avoid potential penalties including loss of federal highway funds.

But Environmental Protection Agency officials have warned that the plan is insufficient — let alone a plan for meeting the current 70 ppb standard, set in 2015."

Bruce Finley reports for the Denver Post November 20, 2016. [2]