Noble Energy Inc. (NYSE: NBL), the U.S. Environmental Protection Agency (EPA), the U.S. Department of Justice (DOJ) and the state of Colorado reached an agreement to improve emission control systems on oil storage tanks in the Denver-Julesberg (DJ) Basin, Noble said April 22.

The tanks might not be in compliance with air regulations, the company added.

A notice of the agreement between all involved parties was filed with the U.S. District Court in Denver. The consent decree will be published in the Federal Register and subject to public comment for 30 days.

Based on the EPA and Colorado's initial review of a relatively small number of older tank batteries, Noble will expand the consent decree to identify additional opportunities to reduce emissions in the basin.

Noble will evaluate, monitor, verify and report on storage tanks’ design, operation and maintenance. This process will go into 2019, and the tanks will be upgraded. Expenditures for the upgrades are not yet quantified, and are not expected to affect basin operations, the company added.

The company will pay $4.95 million in civil penalties and provide $4 million in funding for supplemental environmental projects.

Mitigation projects include retrofitting engines to run on natural gas, upgrading control systems for transferring oil and other liquids from tanks to trucks, and supporting scientific research on sampling and analytical methods for managing pressurized liquids. These measures will cost $4.5 million, Noble added.

Funding for Front Range air quality programs, including incentives to change woodburning stoves and gasoline-powered lawn mowers, will also be provided, the company said.

"By working together with the federal government and the state of Colorado to reduce emissions we are doing the right thing," said Gary Willingham, Noble’s executive vice president of operations. "We're implementing a serious action plan through which we will evaluate tank batteries throughout our DJ Basin operations, remove the tank batteries that should be removed, improve others and implement enhanced environmental strategies."