Of the more than 1,600 sites that have been placed on the National Priorities List in the 30 years since it was established, about 1,100 — or two-thirds of the sites — have reached the construction complete phase.
Of the eight Oklahoma sites on the National Priorities List, three have reached the construction complete phase:
Hardage/Criner in Criner
Mosley Road in Oklahoma City
Cleanup progress has declined since the early 2000s, according to the EPA. During the last decade, the average time from placement on the National Priorities List to construction completion has grown from 12.5 years to 15.5 years, according to the statement.
The Imperial site was on the National Priorities List for eight years before reaching construction completion.
At least once a year, the Oklahoma Department of Environmental Quality inspects the 72-acre abandoned refinery site covered with trees and grass that is bisected U.S. Highway 142 to ensure cleanup is working.