Waste Management Hawaii and two of its top employees entered guilty pleas to reduced misdemeanor charges Friday as part of a settlement agreement with U.S. attorneys in a case involving the spillage of millions of gallons of contaminated storm water from the city’s only municipal landfill into the ocean in January 2011.

The company pleaded guilty to two charges of violating the clean water act and agreed to pay a $400,000 criminal fine payable to the U.S. District Court clerk, and an additional $200,000 in restitution. Of the $200,000, half will go to the Ko Olina Coast Community Association and the other half to the Malama Learning Center.

Joseph Whelan, the company’s vice president and the landfill general manager, and Justin Lottig, the facility’s environmental protection manager, each pleaded guilty to one misdemeanor count of negligence and will each pay $25,000.

The plea agreements stave off a trial that was scheduled to go before U.S. District Judge Susan Oki Mollway on Aug. 4. Instead,a formal sentencing hearing will take place Oct. 26. 

The three parties were served a 13-count indictment last year following the 2011 incident at Waimanalo Gulch Sanitary Landfill, mauka of Ko Olina and next to Kahe Point, alleging that they knowingly committed violations of the U.S. Clean Water Act and then conspired and made false statements to the state Health Department.

Waste Management  had faced a maximum fine of $500,000 for each count while Whelan and Lottig could have been imprisoned.

Attorneys for Waste Management, the largest waste disposal company in the United States, had called the charges baseless and said that the company’s employees even acted “heroically” to divert further harm and possibly even loss of life.