Department of Toxic Substances Control Department of Toxic Substances Control


California statute (Health and Safety Code, section 25201 et seq) requires any person who stores, treats or disposes of hazardous waste to obtain a hazardous waste facilities permit or other grant of authorization to do so (i.e., generators must obtain a permit or other form of authorization to treat their hazardous waste onsite). This differs substantially from that of the federal hazardous waste program. U.S. EPA interprets the accumulation provisions in 40 CFR §262.34 as not only allowing generators to accumulate their waste for the allotted time period (i.e., 90/180/270 days) but also to treat their waste in the accumulation unit, provided the generator complies with the requirements in §262.34 as well as the unit-specific requirements in Part 265 for tanks, containers, or containment buildings. This interpretation allows generators to accumulate and treat hazardous waste on site without obtaining a permit or interim status.

However, since California statute strictly prohibits any treatment without a permit or other form of authorization (e.g., a Permit-by-Rule) DTSC does not have the authority to interpret the accumulation requirements in section 66262.34 (of the California Code of Regulations) to also include treatment as U.S. EPA does.

What is Tiered Permitting?

California has a five-tier permitting program which matches the statutory/regulatory requirements imposed upon each category of hazardous waste facility to the degree of risk posed by them.

Four of these tiers may apply to generators that treat their hazardous waste onsite. These include:

  • The Standardized Permit Tier -   (HSC section 25201.6)
  • The Permit by Rule Tier - (22 CCR sections 67450.1 through 67450.13)
  • The Conditional Authorization Tier - (HSC section 25200.3)
  • The Conditional Exemption Tier - (HSC section 25201.5)
    • The Conditional Exemption (CE) Tier has 4 sub tiers:
      • CESQT - Conditionally Exempt Small Quantity Treatment (Health and Safety Code (HSC section 25201.5(a))
      • CESW - Conditionally Exempt Specified Wastestream (HSC section 25201.5(c))
      • CEL - Conditionally Exempt-Limited (HSC section 25201.14)
      • CECL - Conditionally Exempt Commercial Laundries (HSC section 25144.6(c))