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manage dangerous waste

Count Dangerous Waste

Identify and Designate Waste, then count it. 

"Counting" is measuring the weight of your dangerous waste. The amount of waste generated per month determines the “generator status” of a business. That status determines the rules that apply.

Which Rules Apply? can help you to determine your generator status.

Counting waste is also important in order to Report Waste and to Plan for Pollution Prevention.

Know the Weight of Your Waste

You may weigh your waste with a scale or calculate the weight from a known quantity and density. There are two main ways to calculate the weight of a quantity of a liquid waste:

  1. Weigh one gallon and multiply that weight by the total number of gallons.
  2. Multiply the specific density of the waste (from the material safety data sheet or other source) by the density of water (8.34 pounds). Then, multiply that number by the total number of gallons of liquid waste.

A more detailed discussion of the calculations involved can be found in the Ecology publication, Counting Dangerous Waste Under the Dangerous Waste Regulations.

As a general rule, count dangerous wastes that are accumulated, disposed of, treated, recycled, or shipped off-site on a manifest. 

What Not to Count

Beneficial Reuse/ Recycling discusses waste recycling exemptions from counting and reporting requirements.

Wastes Exempted by Regulation includes conditionally excluded wastes, the domestic sewage exclusion, and selected other wastes.

Treatment by Generator discusses types of on-site waste treatment allowed in tanks and containers.

Related information

Washington Dangerous Waste Designation Tool is a downloadable Excel spreadsheet that can walk you through the process of assigning waste codes to dangerous waste.

Counting Dangerous Waste Under the Dangerous Waste Regulations is a detailed publication on counting waste.

Designation of dangerous waste  is at WAC 173-303-070 in the Dangerous Waste Regulations.