THE SENATE	S.B. NO.	3259
THIRTY-THIRD LEGISLATURE, 2026
STATE OF HAWAII

A BILL FOR AN ACT

Relating to solid waste.

BE IT ENACTED BY THE LEGISLATURE OF THE STATE OF HAWAII:

SECTION 1. The legislature finds that municipal solid waste combustor ash must be properly disposed in a lined landfill to avoid unnecessary exposures. Regulations for the disposal of incinerator ash are, however, based only on short‑term lab tests that study a select number of heavy metals. These short-term lab tests do not test the contents of the ash, but only test for substances that leach out at a pH level where toxic metals such as lead and cadmium are not expected to leach out.

The legislature further notes that peer-reviewed academic research has shown that ash can leach out toxic chemicals such as arsenic in real-life landfill conditions despite having passed the toxicity characteristic leaching procedure test with a non-hazardous categorization. The Environmental Protection Agency added a statement to their website, Energy Recovery from the Combustion of Municipal Solid Waste (MSW), in December 2025, to clarify that non-hazardous municipal solid waste ash "may still present potential risks via other pathways, such as through inhalation, ingestion, or dermal (skin) contact." This statement demonstrates that the Environmental Protection Agency's standards are not based on occupational exposure pathways, including inhalation or ingestion, for workers handling the ash as construction material. These exposure pathways become more likely if ash is not disposed of in a lined landfill but is instead permitted to be deregulated and recycled into roads or for other purposes such as construction or fill. If ash were permitted to be used for roadbuilding, many roads would become linear unlined landfills as the roadways eroded over time.

The legislature recognizes that pursuant to Act 255, Session Laws of Hawaii 2025, landfill units and the components of landfill units are prohibited from being constructed, modified, or expanded within a one-half mile buffer zone of residential, school, or hospital property lines or, if in the city and county of Honolulu, inland of an aquifer. The legislature finds that permitting the inclusion of incinerator ash in construction materials within these buffer zones where a landfill is prohibited from storing the same material is counterproductive to public safety and best practices.

Accordingly, the purpose of this Act is to clarify that municipal solid waste incinerator ash is solid waste that:

(1) May only be disposed of in a double-lined landfill; and

(2) Shall not be used for roadbuilding, fill, construction, or as alternative daily cover material on any landfill.

SECTION 2. Section 342H-30, Hawaii Revised Statutes, is amended by amending subsection (c) to read as follows:

"(c) No person, including any public body, shall discard, dispose of, deposit, discharge, or dump solid waste, or by contract or otherwise arrange directly or indirectly for the disposal of solid waste in an amount equal to or greater than one cubic yard in volume anywhere other than a permitted solid waste management system without the prior written approval of the director. Fly ash, bottom ash, or combined fly and bottom ash from a municipal waste combustor, including any ash residue that remains after removal of metals for recycling into new metal products, shall be disposed of only in a double-lined municipal solid waste or hazardous waste landfill and, beginning December 31, 2026, shall not be utilized as alternative daily cover material on a landfill, roadbuilding, fill, or other construction material; provided that the requirement for the use of double liners shall not apply to the use of Waimanalo gulch sanitary landfill cells constructed and in use as of December 31, 2025. Each day of violation shall constitute a separate offense. This prohibition shall not be deemed to supersede any other disposal prohibitions established under federal, state, or county law, regulation, rule, or ordinance."

SECTION 3. New statutory material is underscored.

SECTION 4. This Act shall take effect upon its approval.

INTRODUCED BY:

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Report Title:

Solid Waste Control; Municipal Waste Combustor Ash; Disposal; Prohibition on Reuse

Description:

Requires municipal solid waste combustor ash to be disposed of only in a double-lined landfill, except for in Waimanalo Gulch Sanitary Landfill cells constructed and in use by 12/31/2025. Beginning 12/31/2026, prohibits the reuse of municipal solid waste incinerator ash for use as daily landfill cover material, roadbuilding, fill, or construction material.

The summary description of legislation appearing on this page is for informational purposes only and is not legislation or evidence of legislative intent.