Colorado Springs Utilities will settle a lawsuit by WildEarth Guardians, which alleged more than 3,000 Clean Air Act violations at the coal-fired Martin Drake Power Plant downtown and sought more than $112 million in fines.

Utilities and WildEarth Guardians have until April 13 to finalize the settlement negotiations, said Samantha M. Ruscavage-Barz, WildEarth Guardians' senior staff attorney.

The New Mexico-based environmental nonprofit claimed through the lawsuit - which was filed in U.S. District Court in February 2017 - that Utilities failed to monitor "opacity" from Drake's smokestacks for more than 300 hours between April 11, 2011, and Dec. 13, 2015. Those measurements show levels of particulates that can cause coughs, aggravated asthma and premature death, among other things.

A bench trial for the lawsuit was scheduled to begin Monday, but last month attorneys notified the court a settlement was in the works.

"We were pleased that we were able to work it out," Ruscavage-Barz said.

She declined to offer further comment, however, citing the unfinished negotiations. The unknown details of the settlement leave unanswered the question of whether Utilities violated Clean Air standards, as the suit alleges.

Representatives from Colorado Springs Utilities could not immediately be reached for comment.

Emissions from Drake contain mercury, soot, sulfur gases, hydrochloric acid and other heavy metals and without proper monitoring, there is no guarantee those elements are not harmful to people in the area, WildEarth Guardians' lawsuit says.

More than 200,000 people live within 5 miles of Drake.

The plant's emissions have long been a point of contention. Most recently, the conversation has shifted to the installation of a controversial scrubber system that cost Utilities about $200 million and aims to reduce sulfur dioxide emissions.

Utilities representatives maintain that the scrubbers work well, though in November 2017, the state Air Quality Control Commission deemed the plant's emissions "unclassifiable" rather than in compliance with federal standards.

Already, one of Drake's three coal-fired units has been shuttered and the other two are scheduled to be decommissioned no later than 2035.

WildEarth Guardians' lawsuit asked the court to order Utilities to comply with opacity monitoring requirements, install equipment to prevent additional violations and to stop operating Drake's coal-fired units until that equipment works properly. It also asked for Utilities to be fined up to $37,500 per violation.