On December 15, 2016, EPA issued a pre-publication version of
new regional haze regulations. The Agency's regional haze
program regulates emissions affecting visibility in national parks,
or "Class I" areas. EPA promulgated the regulations in
1999 with the goal of achieving natural visibility conditions by
2064. Under the program, states must create plans to control
visibility-impairing emissions, and must update these plans every
"planning period" of ten years. The new regulations
are intended to apply to the second planning period, but will
become effective 30 days after the recently released rule is
published in the Federal Register, which is scheduled for January
10th.
Some of the revisions are straightforward, such as delaying the
deadline for the states to submit their plans for the second
planning period by three years. That change is intended to
allow states more time to account for all the many recent changes
in air quality regulations in deciding whether
