Even as the I-70 East expansion project winds its way toward final federal approval, community organizations representing neighborhoods in north Denver adjacent to I-70 joined the Sierra Club on March 15 in a lawsuit.

CDOT is proposing to eventually expand the current six-lane highway to 10 travel lanes and four frontage lanes. Phase 1 of the project is slated to begin next year following federal issuance of a formal “Record of Decision” (ROD) this summer. CDOT is proceeding on a parallel path with selection of a contractor/developer, with a decision expected this fall.

The suit, filed in the U.S. Court of Appeals for the District of Columbia Circuit, challenges EPA’s revision of the methodology for determining compliance with the air quality standard for particulate pollution. The specific claim about EPA guidance revolves around whether multiple high pollution days will be counted against the standard.

The organizations joining the Sierra Club in the suit include Citizens for a Greater Denver, the Elyria and Swansea Neighborhood Association, and the Cross Community Coalition.

In a press release issued March 16, the group alleges increased health risks from the project for an estimated 10,000 residents of north Denver residing within 1,000 feet of I-70.

This same group of organizations has been urging CDOT to re-route interstate highway traffic away from the north Denver neighborhoods onto an expanded I-76 and I-270 combination. In this scenario, I-70 through north central Denver would be converted into a surface boulevard. CDOT opposes this alternative as unrealistic and has been joined in that view by many local and state officials. The public comment period on the preferred alternative closed March 2.