The Environmental Protection Agency on Tuesday fined Exxon Mobil $2.5 million for violating pollution controls at eight of its sites, saying the Trump administration will be holding polluters accountable.

“We will be enforcing environmental laws in this administration ... with prudence and with excellence,” said Deputy Assistant Administrator Patrick Traylor of the EPA’s Office of Enforcement and Compliance Assurance.

Traylor said the agency is “emphasizing the importance of the rule of law in this administration, specifically at EPA.”

Exxon was fined for flaring gases at facilities in Louisiana and Texas. The fine is relatively low — which several reporters on a press call asked about -- but EPA points out that the company will spend nearly $300 million to install air pollution control technology at five of the company's facilities in Texas, near Baytown, Beaumont and Mont Belvieu, and three sites in Baton Rouge, La.

The anti-fossil fuel group 350.org called the fine "a slap on the wrist" from the "fossil-fueled Trump administration," according to Lindsay Meiman, the group's head of communications. "These mild fines are tiny compared to the colossal wealth of fossil fuel elites, and will only embolden Exxon and its ilk in exploiting our planet for profit."

A separate settlement was reached with the Denver company PDC Energy at its fuel refining facilities for violating air quality standards. PDC was also fined $2.5 million, "which will be split evenly between the United States and the State of Colorado," the EPA said.

The companies worked with the EPA to reach a settlement and come back into compliance, Traylor said.

"PDC will spend an estimated $18 million on system upgrades, improved operations and maintenance practices, monitoring, and inspections to reduce emissions," EPA said. "PDC will also be required to implement environmental mitigation projects at certain sites to further reduce [Volatile Organic Compounds] and nitrogen oxide (NOx) emissions at a cost of $1.7 million."