On Monday, a district court judge ruled that the Environmental Protection Agency has a “mandatory duty” to respond to the civil rights complaints it accepts within a 180-day deadline. The ruling is the result of a 2015 lawsuit brought by five environmental groups, including the Sierra Club and Citizens for Alternatives to Radioactive Dumping, in response to the EPA’s failure to address complaints in a timely manner.

Apparently, ineffective enforcement isn’t all that new at the EPA.

“The EPA’s Office of Civil Rights is notorious for being ineffective,” said Adam Babich, an environmental law professor at Tulane University, to Earther.

He’s right. In one instance cited in the lawsuit, the EPA took more than 20 years to begin investigating a complaint against a wood incinerator in Flint, Michigan. That investigation only happened after the St. Francis Prayer Center took part in the recent lawsuit.

Read More: Sorry, EPA: You Can’t Keep Ignoring Civil Rights Complaints