644.041.  Effluent regulations to be promulgated — nutrient management technical standard, requirements, inapplicability. — 1.  As promptly as possible the commission shall adopt and promulgate reasonable effluent, pretreatment and toxic material control regulations which require the use of effective treatment facilities, or other methods to prevent water contamination, for each and every significant source, potential source, and classification of sources of water contaminants, or to limit or prevent introduction of water contaminants into publicly owned treatment works or facilities as required under any federal water pollution control act, throughout the state and thereafter may modify such regulations from time to time.

  2.  Any land application of industrial wastewater, industrial wastewater treatment sludge, and related process wastes, excluding concentrated animal feeding operations, livestock markets, and animal manure, shall be subject to a nutrient management technical standard established and incorporated into rule by the department, which shall include land application practices, annual soil sampling, setbacks, material sampling requirements and frequency, and a process for establishing land application rates.  The nutrient management technical standard shall allow the use of a phosphorus index developed by Missouri's first land grant university, regardless of operational control over land application fields.  Such phosphorus index shall be revised for each annual planned application of such material and include, but shall not be limited to, data inputs for field use, field slope, field management practices, application method, soil type, phosphorus soil test, phosphorus solubility, and tillage type.  Results of any sampling required under this subsection shall be provided to the department.  Such rules shall afford a prudent degree of environmental protection designed to ensure safe and clean soils and water for the surrounding community while accommodating modern agricultural practices.  Any rule or portion of a rule, as that term is defined in section 536.010, that is created under the authority delegated in this section shall become effective only if it complies with and is subject to all of the provisions of chapter 536 and, if applicable, section 536.028.  This section and chapter 536 are nonseverable and if any of the powers vested with the general assembly pursuant to chapter 536 to review, to delay the effective date, or to disapprove and annul a rule are subsequently held unconstitutional, then the grant of rulemaking authority and any rule proposed or adopted after July 9, 2024, shall be invalid and void.

  3.  The provisions of subsection 2 of this section shall not apply to land application conducted in compliance with a land application management plan approved by the department.