Haw. Rev. Stat. § 342D-72: Cesspools; mandatory upgrade, conversion, or connection.

(a) Before January 1, 2050, every cesspool in the State, excluding cesspools granted exemptions by the director of health pursuant to subsection (b), shall be:

(1) Upgraded or converted to a director-approved wastewater system; or

(2) Connected to a sewerage system.

(b) The director of health may grant exemptions from the requirements of subsection (a) to property owners of cesspools that apply for an exemption and present documentation showing a legitimate reason that makes it infeasible to upgrade, convert, or connect the cesspools. For the purposes of this subsection, a legitimate reason shall include but not be limited to:

(1) Small lot size;

(2) Steep topography;

(3) Poor soils; or

(4) Accessibility issues.

(c) As used in this section, "cesspool" means an individual wastewater system consisting of an excavation in the ground whose depth is greater than its widest surface dimension, that receives untreated wastewater, and retains or is designed to retain the organic matter and solids discharged into it, but permits the liquid to seep through its bottom or sides to gain access to the underground geographic formation.