Missouri Revised Statutes Title XL. Additional Executive Departments § 640.116. Exemption from rules, system exclusively serving charitable or benevolent organization, when

1. Any water system that exclusively serves a charitable or benevolent organization, if the system does not regularly serve an average of one hundred persons or more at least sixty days out of the year and the system does not serve a school or day-care facility, shall be exempt from all rules relating to well construction except any rules established under sections 256.600 to 256.640 applying to multifamily wells, unless such wells or pump installations for such wells are determined to present a threat to groundwater or public health.

2. If the system incurs three or more total coliform maximum contaminant level violations in a twelve-month period or one acute maximum contaminant level violation, the system owner shall either provide an alternate source of water, eliminate the source of contamination, or provide treatment that reliably achieves at least ninety-nine and ninety-nine one-hundredths percent treatment of viruses.

3. Notwithstanding this or any other provision of law to the contrary, no facility otherwise described in subsection 1 of this section shall be required to replace, change, upgrade, or otherwise be compelled to alter an existing well constructed prior to August 28, 2011, unless such well is determined to present a threat to groundwater or public health or contains the contaminant levels referred to in subsection 2 of this section.