A water and sewer Investor-Owned Utility (IOU) is a retail public utility owned by an individual, partnership, corporation or homeowners association.

Submetered utility service is water utility service that is master metered for the owner by the retail public utility and individually metered by the owner at each dwelling unit; wastewater utility service based on submetered water utility service; water utility service measured by point-of-use submeters when all of the water used in a dwelling unit is measured and totaled; or wastewater utility service based on total water use as measured by point-of-use submeters.

Allocated utility service is water or wastewater utility service that is master metered to an owner by a retail public utility and allocated to tenants by the owner.