North Carolina-based home-improvement retailing giant Lowe’s has agreed to pay $18.1 million to settle California claims that it illegally disposed of hazardous wastes at more than 100 of its home-improvement stores throughout the state.

The settlement, approved in Alameda Superior Court, closed a civil environmental prosecution following a joint investigation by the California Department of Toxic Substances Control’s Office of Criminal Investigations, more than 30 California district attorneys and the city attorneys of Los Angeles and San Diego. The civil enforcement action filed in Alameda County was led by the district attorneys of Alameda, San Joaquin and Solano counties, which alleged that 118 stores throughout the state unlawfully handled and disposed of hazardous wastes for 6½ years.

The improperly discarded hazardous wastes and related materials included pesticides, aerosols, paint and colorants, solvents, adhesives, batteries, mercury-containing fluorescent bulbs, electronic waste and other toxic, ignitable and corrosive materials.

The probe included state scientists and investigators conducting dumpster examinations to gather evidence from 2011 to 2013. Officials said those examinations revealed that Lowe’s routinely sent hazardous wastes into California landfills that were not permitted to receive those wastes. At some Lowe’s stores, employees were unlawfully throwing away batteries and compact fluorescent light bulbs that customers turned in to be recycled.