HI SB1180

Extends the cesspool upgrade, conversion, or connection income tax credit sunset date from December 31, 2020, to December 31, 2022, and makes the credit refundable for taxpayers with no income tax liability.

Restricts eligibility for the income tax credit by establishing income thresholds based on federal adjusted gross income (specific dollar amounts to be determined), with different thresholds for single filers, head of household, and joint filers.

Requires all cesspools in Hawaii to be upgraded, converted to septic or aerobic treatment unit systems, or connected to sewer systems by January 1, 2050.

Establishes a cesspool compliance grant program to assist homeowners in meeting upgrade and conversion costs, with eligibility limited to those meeting income thresholds specified in the tax credit provisions.

Requires the Department of Health to develop guidelines for mandatory disclosure of cesspools on real property before sale or transfer, making cesspool existence a material fact in seller's disclosure statements.