Mo. Rev. Stat. § 644.082: Discharging water contaminants, permit required — violation, penalties.

It shall be unlawful for any person to operate, use or maintain and discharge water contaminants from any water contaminant or point source or wastewater treatment plant unless he holds a permit from the commission. Any person violating this section shall be deemed guilty of a misdemeanor and shall be fined upon conviction at least one hundred dollars and not more than five hundred dollars and shall be required to apply for such a permit within thirty days.