(a) The offense of endangering the water supply is committed if a person knowingly contaminates a public or private water well or water reservoir or any water supply of a public utility or tampers with the production of bottled or packaged water at a retail or wholesale mercantile establishment.
(b) Endangering the water supply does not include contamination of a public or private well or water reservoir or any water supply of a public utility that may occur in any of the following circumstances:
(1) Inadvertently as part of the operation of a public utility or electrical generating station.
(2) Due to releases, discharges, or emissions that are authorized by state or federal law or that are permitted or licensed by any state or federal agency.
(3) Due to accidental releases from an otherwise lawful activity.
(4) Due to discharges or emissions in excess of permitted or licensed levels provided that federal or state enforcement authority is available to respond.
(c) The offense of endangering the water supply is a Class B felony.