Fines for breaking US pollution laws can vary widely among states—the disparity may violate the Constitution

Colorado's median fine for companies caught violating the federal Clean Water Act is over US$30,000.

In Montana, most violators get barely a slap on the wrist; in Virginia, the typical fine is $9,000; in North Carolina, the median is around $600.

Authors: Disparate enforcement is also unfair, leaving some companies paying far more than others for the same behavior.

They say the EPA has not fulfilled its duty to require robust state enforcement.

The comparatively lenient enforcement in some states is not only unfair, it's ultimately bad for the environment.

Unless we have some uniform system of calculating penalty amounts, the discretion allowed results in vastly different penalties for similar conduct.

Our study focused on the Clean Water Act, but the results should trigger more research to determine whether these issues arise in other environmental areas.