Cal. Health & Safety Code § 25201.13

(a) The Legislature hereby finds and declares that demineralization of water is a standard industrial water purification process used by utilities and industry. The regeneration and recycling of ion exchange media used to demineralize water is a continuous, onsite, totally enclosed, automated process, which is exempt from federal permitting requirements. The conditions set forth in subdivision (d) of Section 25201.5 are important to protect the environment by ensuring notification before treatment begins, written operating instructions, inspections, compliance with pretreatment standards, cleanup of terminated units, and recordkeeping to demonstrate compliance. However, those conditions are inapplicable to demineralization units because of the enclosed, automated, continuous technology involved, the very brief period in which treatment occurs, and the lack of any waste residue. An exemption from Section 25201.5 is therefore appropriate. Similarly, elementary neutralization associated with food processing industry wastewaters should also be exempt from Section 25201.5.
(b) An owner or operator of an elementary neutralization unit, as defined in Section 66260.10 of Title 22 of the California Code of Regulations, and any storage tank not regulated under the federal act which is an integral part of the demineralizer operation, that neutralizes wastes which are hazardous solely due to corrosivity or toxicity that results only from the acidic or alkaline material, is exempt from this article, including the requirement of obtaining a hazardous waste facilities permit or other grant of authorization from the department, if the wastes result solely from the regeneration of ion exchange media used to demineralize water, do not contain more than 10 percent acid or base concentration by weight, are treated in vessels and piping constructed of materials that are compatible with the range of temperatures and pH levels of the wastes, and are subject to appropriate pH and temperature controls.
(c)
1. (1) An owner or operator of an elementary neutralization unit, as defined in Section 66260.10 of Title 22 of the California Code of Regulations, including any storage or processing tank not regulated under the federal act which is an integral part of the elementary neutralization operation, is exempt from this article, including the requirement to obtain a hazardous waste facilities permit or other grant of authorization from the department, if all of the following requirements are met:
  1. (A) The unit neutralizes wastewaters which are hazardous solely due to corrosivity or toxicity that results only from alkaline or acidic materials used in the owner’s or operator’s food processing operations.
  2. (B) The wastewaters result from food processing operations, do not contain more than 10 percent acid or base concentration by weight, are treated in vessels and piping that are compatible with the range of temperatures and pH levels of the wastewaters, and are subject to appropriate pH and temperature controls.
2. (2) For purposes of this subdivision “food processing operation” means activities conducted at facilities in SIC Code Major Group 20 (Food and Kindred Products), and includes preparation, mixing, cooking, fermentation, aging, storage, packaging, sanitizing, or pasteurization of products intended for human consumption, and all associated equipment and vessel cleaning operations.