Episodic generation of dangerous waste

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Unplanned events require immediate action!

Email or fax us within 72 hours of an unplanned event. You must also report a spill if the unplanned event involves dangerous waste or hazardous substances, no matter the size or amount.  

The episodic generation rules allow small and medium quantity generators to maintain their current generator category, even when larger-than-normal waste amounts are generated from qualifying episodic events. Using this rule is optional.

To take advantage of this rule, you must:

  • Notify your regional Ecology contact within specific timeframes based on the type of episodic event (planned or unplanned).
  • Fill out a Site ID form.
  • Fill out an Episodic Addendum form.

Report a spill

You must also report a spill if:

  • Any unplanned event involves spills of dangerous waste or hazardous substances.
  • A spill poses a threat to human health or the environment, regardless of size.

What’s an episodic event?

Episodic event is an activity, either planned or unplanned, that:

Planned vs. unplanned

  • Planned event is an episodic event you planned and prepared for, such as tank cleanouts, short-term projects, or removal of excess chemical inventory.
  • Unplanned event is an unexpected episodic event or one you did not plan for, such as a production process upset, product recall, accidental spill, or "act of nature," such as a tornado, hurricane, earthquake, flood, or wildfire.

You can manage waste from one planned or unplanned episodic event per calendar year under this rule provided you notify us correctly. Follow the instructions below.

How and when do you notify Ecology of an episodic event?

Notification deadlines and requirements for episodic events

If you’d like to manage your dangerous waste under the episodic generation rules, you must:

  1. Get an EPA/State Identification Number (if you don’t already have one).
  2. Notify us in time:
    • Unplanned events: Within 72 hours of event
    • Planned events: 30 days before event occurs (60 days are recommended)
  3. Submit the required forms.

How should waste from an episodic event be handled?

On-site management requirements

Accumulate episodic waste in tanks and containers, which are:

  • In good condition.
  • Compatible with the waste.
  • Kept closed (except when adding or removing waste).
  • Clearly marked or labeled.


Clearly label or mark your tanks and containers with the:

  • Words “Episodic Dangerous Waste” or “Episodic Hazardous Waste.”
  • Hazards associated with the waste (ignitable, corrosive, reactive, and/or toxic).
  • Episodic event start date.

Except for the start date, labels must meet the dangerous waste requirements:

  • Be legible from 25 feet away,
  • Lettering size must be at least 0.5 inches high.

For containers one gallon (or four liters) and under, labels, markings, and lettering can be appropriate for the size of the container.

Off-site disposal

Send episodic waste to a treatment, storage, and disposal facility within 60 calendar days from the start date of the event.

On-site treatment

Medium quantity generators (MQGs) may treat episodic waste within 60 calendar days from the start date of the event. Small quantity generators (SQGs) may not treat episodic waste on-site.

Frequently asked questions