Gwinnett County fire hazmat crews responded to the scene before the EPD took over the investigation.
Bert Langley, the EPD's director of compliance, previously told The Atlanta Journal-Constitution that the agency knows little at this point — but the DNC is unlikely to be held responsible.
"Assuming the situation is that they pulled up and the charter operator decided this was a good place to empty the holding tank," Langley said, "any action we would take would be against the charter company."
Such "action" would typically include help with cleanup and a monetary settlement.
Officials have not released the name of the charter company. A possible timeframe for the investigation's completion was not clear.