Stefan Wohl (search) is charged with misdemeanor counts of reckless conduct and discharging contaminates to cause water pollution, Cook County State's Attorney Dick Devine said. The charges carry a maximum penalty of one year in jail and a $10,000 fine.
Wohl, 42, of Selma, Texas, turned himself in to Chicago police Wednesday and was released on his own recognizance, authorities said.
According to authorities, Wohl was driving alone to a downtown hotel Aug. 8 when he allegedly emptied the bus's septic tank as it crossed the metal grates of a bridge.
The waste poured through the grates and onto the open deck of the Chicago's Little Lady tour boat, which was passing below with more than 100 people on board.
Prosecutors relied on surveillance tapes and consulted engineers about the releasing of the waste before filing charges. "We were satisfied with what they told us that it could not have been an accident," prosecutor Robert Egan said.
Calls to Wohl's attorney, Mark Rotert, were not immediately returned Wednesday.
No one was hurt in the incident, but officials with the Chicago Architectural Foundation, which operates the boat tour, said they have received several angry calls from passengers demanding compensation for clothing and personal items.
Illinois Attorney General Lisa Madigan has filed a lawsuit seeking $70,000 in damages against the band and the driver, alleging they violated state environmental laws.
At the time, a band spokesman said that Wohl had said he was not involved with the incident.
An October-dated statement on the band's Web site said that although "we still do not have a definitive understanding of what happened," the band would work with affected passengers to "make things right for all concerned" and make $50,000 donations to the Chicago Park District and Friends of the Chicago River.
The band's statement said the incident "is awful and it goes against so many principles we hold dear: environmentalism, accountability, and, mostly, principles of humanity."
Prosecutors said the band cooperated in the investigation, including flying violinist Boyd Tinsley, who used the bus, from California to Chicago to be interviewed and bringing the bus back to the Chicago area for inspection.