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.
NOTE: Unplanned events require immediate action! Contact us within 72 hours.
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:
- Does not normally occur during generator operations.
- Results in an increase of dangerous waste generated that exceeds the calendar month Quantity Exclusion Limits (QELs) for your generator category.
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?
If you’d like to manage your dangerous waste under the episodic generation rules, you must:
- Get an EPA/State Identification Number (if you don’t already have one).
- Notify us in time:
- Unplanned events: Within 72 hours of event
- Planned events: 30 days before event occurs (60 days are recommended)
- Submit the required forms.
Planned episodic events
Step 1: Plan ahead:
We must receive your request (Step 2) at least 30 days before your planned event, but 60 days is recommended to ensure the entire review process can be completed in time.
If we receive your form less than 30 days before the proposed start date, we will change your start date to meet the minimum 30-calendar day requirement. We will inform you of the revised event start date.
Step 2: Submit the required forms
Submit the following forms by mail, postmarked at least 30 days before your event:
- Fill out and print the Episodic Addendum form.
- Include your completed pre-printed Site ID form (available through TurboWaste).
- Mail to this address:
HWTR Annual Reporting Team
P.O. Box 47658
Olympia, WA 98504
Step 3: Wait for confirmation
Wait for confirmation that your forms have been received and accepted as complete. We will contact you once your planned event paperwork has been accepted.
DO NOT proceed with a planned episodic event until you receive confirmation.
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.
Send episodic waste to a treatment, storage, and disposal facility within 60 calendar days from the start date of the event.
Medium quantity generators may treatment episodic waste within 60 calendar days from the start date of the event following .
Small quantity generators (SQGs) may not treat episodic waste on-site.
Frequently asked questions
You may have one episodic event per year, whether planned or unplanned. It is possible, though, to have one additional episodic event, if:
- It is an episodic event of the opposite type. For instance, if the first episodic event was planned, the second one must be unplanned, AND
- You submit a petition and receive approval first.
Yes. Although your generator category remains the same, episodic waste still counts towards the Hazardous Waste Planning Fee and Pollution Prevention (P2) Planning.
Learn more about filing your Dangerous Waste Annual Report.
Yes. If you want to manage your waste as an episodic event, you must complete the steps outlined on this page.
If it's an unplanned event, contact the Hazardous Waste and Toxics Reduction Program by email or fax within 72 hours of the unplanned event.
The Statewide Environmental Incident Report Form (ERTS) does not substitute for the notification required under WAC 173-303-173(3)(b) and WAC 173-303-173(4)(b).
Yes, but only if you are accumulating episodic dangerous waste in tanks. Tanks must be inspected at least once each operating day to ensure all discharge control equipment is in good working order. This includes checking:
- Waste feed cutoff systems
- Bypass systems
- Drainage systems
Daily tank inspections must also ensure the tank is operated according to its design by reviewing the data gathered from monitoring equipment such as pressure and temperature gauges from the inspection.
Consider using the Medium Quantity Generator Tank Inspection Log to document your inspections.