The Interior Department will lead a review of the Colorado mine spill that tainted rivers in three western states.

The review was announced late Tuesday after elected officials from both parties questioned whether the Environmental Protection Agency should be left to probe its own heavily criticized response to the disaster. EPA and contract workers accidentally unleashed 3 million gallons of contaminated wastewater on Aug. 5 as they inspected the idled Gold King mine.

The Interior Department's report is expected to be released publicly in 60 days.

In addition, EPA's inspector general is conducting a separate review. Leaders of oversight committees in both the House and Senate say they are planning hearings after Congress returns from its August recess.

All six senators from the three states involved — Colorado, New Mexico and Utah — wrote EPA Inspector General Arthur Elkins on Wednesday asking him to look into more than a dozen questions, including details of the work being done when the spill occurred and the qualifications of the on-scene crew.

The senators also asked what laws and policies govern the EPA's communications with state, local and tribal governments after such an incident and whether the agency met those requirements.

Numerous local officials have complained the EPA was slow to notify them. The senators asked whether the time lapse created any health hazards or delayed the response.

New Mexico Gov. Susana Martinez on Wednesday called for her state's environment department to launch its own investigation. Aside from what led up to the spill, she said the investigation will examine how residents, businesses and communities along the rivers were notified in the aftermath of the spill.

"New Mexicans deserve answers as to why this catastrophe happened and why the EPA failed to notify us in a timely manner," she said, adding that the federal agency has hounded private citizens and businesses for doing far less.