Counting dangerous waste

If your business generates dangerous waste, you are required to know how much of this waste you generate each month — we call this “counting.”

Counting means you know the weight of your dangerous waste. This can include wastes that you:

Generate.
Accumulate.
Dispose of, treat, or recycle.
Ship off-site on a manifest.

Read our Counting Dangerous Waste publication for detailed guidance.

Health care facilities and pharmaceuticals

If you are a health care facility, please go to our Pharmaceutical Waste Management page for more detailed instructions on counting your waste.

Health care facilities must count both pharmaceuticals and non-pharmaceutical waste.

Why count dangerous waste?

The type and amount of waste you generate each month determines your generator category. Your generator category determines which rules apply to your business. It is also needed to fill out your:

Dangerous Waste Report.
Pollution Prevention Plan (if required).

How to count or find the weight of waste

There are three ways to count or find the weight of your waste. Read our Counting Dangerous Waste publication for more detailed information.

Some tips when counting:

Count your dangerous waste each month.
The highest amount you generate (or accumulate) in any month is what determines your generator category.
Do not average multiple months over time.

What not to count

The Dangerous Waste Regulations conditionally exclude some dangerous wastes (WAC 173-303-071). Tthey are not subject to most of the dangerous waste rules, including counting and annual reporting requirements. Usually, the waste must meet a set of specific conditions in order to qualify for the exclusion.

Common exclusions include:

Treated wood waste.
Polychlorinated biphenyls (PCBs).
Waste reclaimed and reused in a closed loop system.

Learn more about excluded wastes and how to designate them.

Special wastes are state-only excluded wastes with their own set of management requirements. Special wastes pose a relatively low hazard to the environment. Subject to approval, they may be disposed of in municipal landfills or recycled. Examples of special wastes include:

Category D toxic wastes (D004-D043 waste codes).
Solid corrosive waste.
Low-level persistent waste, such as halogenated organic compounds (HOCs) and polycyclic aromatic hydrocarbons (PAHs).

Learn more about the conditional exclusion of special wastes (WAC 173-303-073) or read our Focus on: Special Waste Exclusion publication.

The special waste category also includes waste generated from the salvaging, rebuilding, or discarding of transformers, capacitors, or bushings as listed in WAC 173-303-9904.

The domestic sewage exclusion (as described in WAC 173-303-071) allows dangerous waste to be discharged to a publicly owned wastewater treatment works (POTW). Washington’s version of the domestic sewage exclusion is more stringent than the federal exclusion.

To meet the exclusion rules, the waste must:

NOT exhibit hazardous or dangerous waste characteristics — such as flammability, reactivity, toxicity, or corrosivity—at the point of discharge if it isn’t treatable by the POTW.
NOT exceed any of the dangerous waste concentration thresholds in WAC 173-303-0902 at the point of discharge if it isn’t treatable by the POTW.
NOT be a hazardous or dangerous waste pharmaceutical.
Be treatable by the POTW receiving the waste to a significant degree (rather than just passing through to the sludge or effluent of the POTW).

Read our Focus on: Domestic sewage exclusion publication for more details.

Contact information

Need help?
Contact a dangerous waste inspector in your region.