2023 California Code › Health and Safety Code - HSC › DIVISION 20 - MISCELLANEOUS HEALTH AND SAFETY PROVISIONS › CHAPTER 6.5 - Hazardous Waste Control › ARTICLE 4 - Listings › Section 25143.5.

25143.5. (a)  Except as provided in subdivisions (d), (e) and (f), the department shall classify as nonhazardous waste any fly ash, bottom ash, and flue gas emission control residues, generated from a biomass combustion process, as defined in subdivision (g), if the combustion process will be adequately monitored and controlled so as to prevent the handling or the disposal of any waste in a manner prohibited by law, unless the department determines that the ash or residue is hazardous, by testing a representative sample of the ash or residue pursuant to criteria adopted by the department.
(b)  The fly ash, bottom ash, and flue gas emission control residues that are classified as nonhazardous by the department are exempt from this chapter.
(c)  An operator of a biomass facility which converts biomass into energy for which the department has classified the ash or residue as hazardous shall notify the department whenever there has been a significant change in the waste entering the combustion process, the combustion process itself, or in the management of the ash or residues generated by the facility. An operator of a biomass facility that converts biomass into energy, with regard to which the department has classified the ash or residue as nonhazardous, shall notify the department when there has been a significant change in the waste entering the combustion process or in the combustion process itself.
(d)  For purposes of classifying fly ash, bottom ash, and flue gas emission control residues generated by the combustion of municipal solid waste in a facility, with regard to which the department classified the ash or residue as nonhazardous, on or before January 1, 1985, the sampling of the ash or residue, for purposes of classification by the department, shall occur at the point in the process following onsite treatment of the ash or residue.
(e)  Notwithstanding any other provision of law, this section applies only to fly ash, bottom ash, and flue gas emission control residues which are not RCRA hazardous waste.
(f)  Notwithstanding any other provision of law, the test specified in the regulations adopted by the department with regard to a waste exhibiting the characteristic of corrosivity if representative samples of the waste are not aqueous and produce a solution with a pH that is less than, or equal to, two or greater than, or equal to, 12.5, as specified in paragraph (3) of subdivision (a) of Section 66261.22 of Title 22 of the California Code of Regulations, as that section read on January 1, 1996, shall not apply to ash generated from a biomass combustion process that is managed in accordance with applicable regulations administered by the California regional water quality control board, is used beneficially in a manner that results in lowering the pH below 12.5 but above 2.0, is not accumulated speculatively, and is available for commercial use.
(g)  For purposes of this section, the following definitions shall apply:
(1)  “Biomass combustion process” means a combustion process that has a primary energy source of biomass or biomass waste, and of which 75 percent of the total energy input is from those sources during any calendar year, and of which 25 percent or less of the other energy sources do not include sewage sludge, industrial sludge, medical waste, hazardous waste, radioactive waste, or municipal solid waste.
(2)  “Biomass” or “biomass waste” means any organic material not derived from fossil fuels, such as agricultural crop residues, bark, lawn, yard and garden clippings, leaves, silvicultural residue, tree and brush pruning, wood and wood chips, and wood waste, including these materials when separated from other waste streams. “Biomass” or “biomass waste” does not include material containing sewage sludge, industrial sludge, medical waste, hazardous waste, or radioactive waste.
(Amended by Stats. 1996, Ch. 962, Sec. 2. Effective January 1, 1997.)