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The lifecycle of hazardous waste: What happens to a hazardous product after you drop it off?

A Haz Waste Program employee in protective gear sorts hazardous products into plastic bins.

King County residents and businesses safely disposed of more than 3.9 million pounds of hazardous products in 2023. But have you ever wondered what happens to all those batteries, cans of paint, and bottles of oil once they leave the trunk of your vehicle? Each item we collect embarks on a unique journey.

Once you drop off your hazardous waste, each product is carefully sorted by type and assessed by our collections team. Batteries are sent to specialized recycling facilities where valuable metals are extracted and repurposed to give them a new life. These metals go on to make any number of things, from new batteries to golf clubs.

From Waste to Resource: Reprocessing Materials

Something similar happens to motor oil and antifreeze. These materials are sent to recycling facilities where they are processed to be remade back into their original product and reused again. By ensuring each item is handled appropriately, we not only protect our environment but also conserve valuable resources.

Treatment Processes: Neutralizing Hazards

Not everything can be reborn, however. Products like jewelry cleaners, drain cleaners, and concrete driveway cleaners that fall on the far ends of the pH scale (acid or base) are sent to treatment facilities. Once processed and brought back to a neutral state, these substances then go through the wastewater treatment process for safe disposal.

Safe Destruction: Incineration for the Most Harmful Chemicals

Pesticides, herbicides, and some other harmful chemicals are sent off to be incinerated and destroyed after being collected. Though these products may not get a feel-good ending and be reused, properly disposing of these hazardous items keeps them out of your home and the environment.

“With hazardous waste, a little goes a long way,” said Julie Mitchell, who oversees the collections at the Hazardous Waste Management Program. “The certified incinerators where our materials go are heavily regulated. The chimneys of the plants burn the waste materials to ash, heat, and gas that is filtered in the chimneys to have the lowest impact possible on our environment. If those products go in the garbage or landfills, there are none of those safeguards, and they can leach into our groundwater and waterways.”

The Bigger Picture: Protecting Our Community and Environment

Regardless of where your household hazardous waste goes after you bring it to our disposal sites or local Wastemobile events, it’s all part of the bigger picture of pitching in to protect families, communities, and our environment.

“We have to take extra care with these materials by properly disposing of this stuff at our facilities,” Mitchell said. “It’s free, so it doesn’t cost anything to protect the environment and human health.”

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