The 1999 Regional Haze Rule (RHR) requires States to develop State Implementation Plans (SIPs) to reduce visibility impairment with the express intent that by 2064 the visibility in all Class I areas will be returned to natural conditions. The Delaware Department of Natural Resources and Environmental Control (DNREC) submitted its original Regional Haze SIP to the U.S. EPA on Sept. 25, 2008. On July 19, 2011, the EPA published a final rule approving Delaware’s Regional Haze SIP (76 FR 42557).
The RHR at 40 CFR 51.308(g) requires periodic reports evaluating progress towards the reasonable progress goals established in the SIP. The first progress report is due five years from submittal of the initial SIP, or September, 2013 for Delaware. DNREC finalized the periodic update on Sept. 24, 2013 for the only Class I area Delaware was determined to significantly impact, e.g., the Brigantine Wilderness Area in New Jersey.