As he leaves office this week, Deputy Attorney General Rod Rosenstein will be rightfully honored for countless contributions to the rule of law. Among these will be the recently issued Justice Manual and, notably for environmental lawyers (although perhaps missed by some), overseeing reforms impacting environmental enforcement.

The Justice Manual serves as a convenient compilation of hundreds of distinct DOJ policies that guide the work of lawyers at Main Justice and across the 93 U.S. Attorney's Offices. For the public, it is also a helpful resource for better understanding the DOJ generally. Updating the Justice Manual—the first such effort in 20 years—has made a valuable contribution to law enforcement and good government. And, taken together, the Justice Manual and related reforms at the Environment and Natural Resources Division (ENRD) and elsewhere at the DOJ should improve environmental enforcement in several ways.

First, the Justice Manual recalibrates how the DOJ prosecutes cases, including environmental enforcement matters.