Home Depot is paying nearly $10 million to settle a civil case filed by state and Los Angeles County prosecutors over the retailer’s failure to properly store and transport hazardous waste, the LA Times reports.

An investigation began after a 55-gallon drum at Home Depot’s Marina del Rey store blew up in 2004. Investigators later discovered that chemicals were mixed together into an explosive brew. After the explosion, a waste hauler contracted by Home Depot was driving a truck not certified by the state.

The investigation concluded that Home Depot routinely collected its hazardous waste and placed it in large buckets for offsite disposal. Haulers sometimes improperly stored and labeled the waste and did not keep good records.