When the Environmental Protection Agency issues a regulation, the rule should do more good than harm.

That hasn’t always been obvious to the EPA, and to some, it still isn’t obvious.  

In 2012, the Obama administration finalized the Mercury and Air Toxics Standards (the “MATS” rule), allegedly to reduce emissions of mercury and other hazardous air pollutants from coal- and oil-fired power plants.

But the EPA didn’t consider the $9.6 billion in annual costs of the rule, thereby not caring whether the rule did more harm than good

In 2015, the U.S. Supreme Court in Michigan v. EPA held that the EPA was required to consider the costs of the rule based on the relevant section of the Clean Air Act.

In its response to being required to consider costs, the Obama administration manipulated the alleged benefits of the rule.

The EPA didn’t worry about whether reducing mercury and other hazardous air pollutant emissions from power plants provided enough benefits to justify the rule. It didn’t, and it wasn’t even close. The benefits were minuscule, at only $4 million to $6 million annually, compared with the $9.6 billion annual cost. 

To justify the rule, the EPA made questionable claims of ancillary (secondary) benefits from reducing particulate matter, even though particulate matter had nothing to do with the purpose of the rule. Those indirect benefits accounted for an absurd 99.9% of the monetized benefits.

Here are just two reasons why overreliance on secondary benefits matters:

First, the EPA never would have to justify the purpose of its rules if an overreliance on secondary benefits were allowed.

In many instances, the agency wouldn’t need to figure out whether there are any benefits of regulating a targeted pollutant. EPA officials have seemed to understand this, which explains why they didn’t bother to try to figure out those benefits for several major air regulations.

Secondly, the EPA could do end runs around the law.

When 99.9% of the benefits come from addressing particulate matter, the rule can’t be accurately described as a mercury rule. It’s a particulate matter rule.

Dressing up a particulate matter rule as a mercury rule shouldn’t allow the EPA to avoid any legal prohibition that otherwise would exist if the rule were accurately classified as a particulate matter rule.

And there very well could be legal prohibitions that exist. For example, if the EPA wanted to address particulate matter, there’s already a specific Clean Air Act section to do so (and it isn’t the hazardous air pollutant section used to authorize the mercury rule).

Now the good news: More than a year ago, the EPA proposed a rule that would put an end to this overreliance on secondary benefits in the mercury rule. The EPA, however, needs to get moving and finalize this critical rule.

When it does finalize the rule, the EPA would be making it clear that the Clean Air Act section dealing with hazardous air pollutant emissions from power plants doesn’t authorize those types of regulatory games. 

Further, it might help to set the precedent that those abusive practices won’t be employed with other regulations authorized under different sections of the Clean Air Act.

For those who believe in following the law and commonsense, this rule will be welcomed.