If your facility has a used coolant or antifreeze tank and the contents are classified as hazardous waste, that tank needs the same PE-stamped certification as your used oil tank. This is one of the most commonly overlooked requirements we see, facilities certify their oil tanks and forget about the coolant tank sitting right next to it.
Here is how tank certification applies to used coolant systems.
Why Coolant Tanks Fall Under the Same Rule
Many used coolants and antifreeze mixtures are classified as hazardous waste in California due to heavy metals or other contaminants picked up during use. If you store them in a fixed, above-ground tank, that tank is subject to Title 22 hazardous waste tank certification requirements, the same regulation that covers used oil tanks, solvent tanks, and any other hazardous waste storage.
The regulation does not distinguish between waste types. A 250-gallon used coolant tank has the same certification requirement as a 1,000-gallon used oil tank. If it is a fixed tank holding hazardous waste, it needs to be certified.
Where We See This Come Up
The most common scenario: an auto dealership or fleet shop gets their used oil tanks certified, but nobody mentions the coolant tank. Two years later, the CUPA inspector (often a fire department inspector) comes through and flags it.
Other common situations:
- A machine shop with cutting fluid waste stored in a small fixed tank, often tucked in a corner and easy to miss
- A fleet operation where coolant and oil tanks are in the same shed but only the oil tanks were on the original scope
- A facility that recently added a coolant collection tank and did not realize it triggered a certification requirement
The Simple Fix: Certify Everything in One Visit
If you have both used oil and used coolant tanks (which most auto and fleet shops do) we certify all of them in the same visit. Same process, same report, same PE stamp. There is no reason to handle them separately. Adding a coolant tank to an existing assessment is straightforward and avoids a second site visit later.
If your oil tanks are already certified and the coolant tank was missed, we can come back and certify it on its own. But if you are scheduling a new certification or recertification, mention every tank that holds hazardous waste, oil, coolant, solvent, whatever it is. We will scope them all.
What the Certification Involves
The process for a coolant tank is identical to any hazardous waste tank certification:
- Visual inspection of the tank for condition and material integrity
- Leak testing to confirm the tank is not losing contents
- Seismic evaluation and anchoring calculations
- Secondary containment verification
- PE-stamped certification report
For a single coolant tank, this adds minimal time to an existing site visit. The certification is valid for five years.
Have a coolant tank that needs certification? Call (925) 551-7300 or book a meeting. Tell us what tanks you have, oil, coolant, solvent, all of it. We certify everything in one visit and deliver one PE-stamped report. No reason to make two trips.
Frequently Asked Questions
Is used coolant considered hazardous waste in California?
It depends on the specific chemistry and how it was used. Many spent coolants contain heavy metals or other contaminants that cause them to be classified as hazardous waste under California’s broader definition. If your CUPA has flagged your coolant tank, they have likely already made that determination for your facility.
Can coolant tanks be certified at the same time as waste oil tanks?
Yes. We certify all qualifying tanks at your facility during the same visit. If you have both waste oil and used coolant tanks, handling everything at once is more efficient and avoids multiple scheduling disruptions.
My coolant tank is small. Does it still need certification?
There is no size exemption under the Title 22 hazardous waste tank certification requirement. If the tank is above ground, holds material classified as hazardous waste, and is at a California facility, it needs to be included in your certification.
