If you operate a facility in California with tanks that store or treat hazardous waste, you may need what’s called a hazardous waste tank certification. The regulation is straightforward, but the language is technical, so let’s break it down into plain questions you can answer right now.
This applies to facilities under California Title 22 Code of Regulations, sections 66265.191 through 66265.196. If you’re wondering whether it applies to you, work through the checklist below.
The Quick Filter: Four Questions
Answer these four questions. If you answer “yes” to all of them, you almost certainly need a tank certification.
1. Is the tank above ground?
If your tank is buried or underground, it falls under a different regulation: the Underground Storage Tank (UST) program. That’s a separate certification. We’re talking about above-ground tanks, tanks that sit on the floor or are mounted on a structure.
2. Does it hold hazardous waste?
This is the key distinction. The regulation applies only to tanks storing or treating hazardous waste, not to tanks holding virgin (new) materials or products.
Common examples that count as hazardous waste:
- Waste oil (from machinery, engines, hydraulic systems)
- Waste coolant or cutting fluids
- Wastewater from treatment systems
- Rinse water from degreasing operations
- Spent solvents
- Acid or caustic waste from neutralization or processing
Common examples that do NOT count:
- New motor oil or hydraulic fluid (virgin products)
- Fresh coolant or cutting fluids before use
- Domestic wastewater or gray water
- Non-hazardous waste streams
3. Is it a fixed, stationary tank?
Portable containers, like 55-gallon drums sitting on the floor, generally don’t require certification under this regulation. However, if you have a small fixed tank that’s bolted or anchored down and holds hazardous waste, it counts, even if it’s only a few hundred gallons.
4. Are you in California?
Title 22 is a California state regulation. If your facility is outside California, different rules apply.
Scenarios That DO Require Certification
- Waste oil tank at an auto fleet shop or maintenance facility
- Waste coolant tank at a machine shop or industrial or manufacturing facility
- Equalization or neutralization tank holding treated wastewater
- Batch treatment system for hazardous waste
- Acid or caustic storage tank for hazardous waste (not virgin product)
- Rinse tank from a degreasing or cleaning operation
In all these cases, the tank itself must be certified as meeting California standards for construction, anchoring, secondary containment, and material compatibility.
Scenarios That Do NOT Require Certification
- Product storage tanks holding new or virgin materials (oils, coolants, solvents)
- Portable 55-gallon drums in storage areas
- Underground storage tanks (these fall under the separate UST program)
- Tanks holding non-hazardous waste or domestic wastewater
- Tanks on vehicles or mobile equipment
The “I Didn’t Know” Factor
Many facilities discover this requirement only after they’ve been operating for years, sometimes only when a local CUPA (Certified Unified Program Agency, often the fire department) conducts an inspection and identifies the gap.
This is normal. It doesn’t mean you did something wrong. Hazardous waste tank certification isn’t something most facility managers encounter in their day-to-day work, and the regulation uses technical language that can easily be missed.
If you’ve been cited for this, you’re in good company, and the path forward is clear. Getting certified is straightforward.
When in Doubt
If you’re unsure whether any of your tanks fall under this regulation, call us. Describe what’s in the tank, how it’s stored, and where it is, and we can tell you in minutes whether certification applies.
We certify tanks across California. We handle everything from the site visit to testing and documentation. You just need to give us access.
Frequently Asked Questions
Does used oil require tank certification?
If you store used oil in an above-ground tank and the oil is classified as hazardous waste under California regulations, yes. Many auto dealers and fleet shops discover this requirement when a CUPA inspector flags their waste oil tanks during a routine visit.
Do double-walled tanks still need certification?
Yes. A double-walled tank provides secondary containment, but it still needs to be assessed for structural integrity, material compatibility, seismic anchoring, and proper containment capacity. The double wall is part of the system we evaluate, not a substitute for certification.
What happens if I don’t get my tanks certified?
Your CUPA (typically the local fire department) can issue violations, impose fines, and in serious cases, order you to stop storing hazardous waste until the certification is complete. Most facilities avoid this by responding to the initial notice promptly.
Are underground storage tanks (USTs) included in this requirement?
No. The Title 22 hazardous waste tank certification applies to above-ground tank systems. Underground storage tanks fall under a separate program with different regulations and inspection requirements.
