A city contractor and two of its top officials entered not-guilty pleas Tuesday in U.S. District Court to charges linked to the discharge of hundreds of millions of gallons of contaminated stormwater from the city’s Waimanalo Gulch Sanitary Landfill into the ocean near Ko Olina Resort.

A July 22 trial date was scheduled for Waste Management of Hawaii and its general manager and vice president, Joseph Whelan, and environmental protection manager, Justin Lottig, who were named in a 13-count federal indictment in connection with the January 2011 discharge of contaminated stormwater.

The charges include knowingly committing violations of the U.S. Clean Water Act and then conspiring and making false statements to the state Health Department.

If convicted, the company faces a maximum criminal fine of $500,000 for each count, and Whelan and Lottig could face federal prison terms.

Both are still at their jobs at the facility.