Onsite waste management districts and septage holding tanks.

Amends the definition of "onsite residential sewage discharging disposal system" to provide that the term includes a system that employs advanced treatment components to reduce the concentration of the pathogenic constituents of the effluent to an acceptable level before the effluent is discharged. Amends the law that prohibits the point source (i.e., above ground) discharge of treated sewage from a dwelling, which includes an exception to the prohibition for one particular county that has a onsite waste management district, to make the exception applicable to any onsite waste management district. Authorizes the adoption of rules or guidelines to provide guidance to a local health department that has jurisdiction in a county onsite waste management district and that is authorized to issue operating permits for onsite residential sewage discharging disposal systems that discharge effluent above ground. Provides that, if amending the National Pollutant Discharge Elimination System (NPDES) general permit issued by the department of environmental management (department) for the purposes of the county onsite waste management district law is necessary or advisable to enable new county onsite waste management districts to function properly and effectively, the department shall amend the general permit as soon as reasonably possible after June 30, 2023. Provides that septage that originates from a residential or commercial source may be held in one or more holding tanks of not more than 10,000 gallons until removed and transported from the site. Establishes requirements for septage holding tanks. Requires a permit from the local health department for the operation of a septage holding tank. Requires a septage tank owner to: (1) enter into a written contract with a septage management vehicle operator for regular removal of septage from the tank; (2) provide a copy of the contract to the local health department; and (3) provide proof to the local health department that the tank owner is regularly paying for the removal of septage from the holding tank. Requires a local health department to report to the department concerning the septage tanks in its jurisdiction, and authorizes the adoption of rules or guidelines concerning the reports.