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Biosolids Recycling

For more information about the Biosolids Recycling Program, please send us an email message or contact us at: 

King County Wastewater Treatment Division
Resource Recovery
201 S. Jackson Street
Mail Stop: KSC-NR-0512
Seattle, WA 98104
Phone: 206-477-5557
Fax: 206-684-2057

Biosolids...a sustainable choice

Biosolids are the nutrient rich organic product of wastewater treatment - a never ending resource. We are using biosolids to return valuable nutrients and carbon to the land. Research shows that biosolids enriches soils and keep them productive and healthy! King County's Loop® biosolids are recycled as a fertilizer and soil conditioner in agriculture and forestry, and a portion of our biosolids is composted by a private company and sold as GroCo for use in landscaping and gardening.

If you have any questions or comments, please don't hesitate to contact us.


All about biosolids

All about biosolids
Find basic information on Loop® biosolids: what they are, where they come from, and what we  do with them.

Groco

Garden compost
GroCo is a soil-enhancing compost made with Loop biosolids. Find out more about GroCo, including where to get it.

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What we're doing to minimize climate change
Learn how carbon in biosolids is stored in the soil and reduces greenhouse gas emissions.

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Our soil improvement projects
Come find out more about how we're using Loop® to improve soils and plants in Washington.

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Safety and regulations
Get the facts on biosolids safety and the regulations governing the production and use of Loop biosolids.

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Concerned about something you've heard recently about biosolids? Learn more about the myths and realities of biosolids. 
 
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FAQ
Have a question about biosolids, King County's biosolids program, or anything else related to Loop? We've got an answer for you.

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Documents & Links
Download brochures, reports and technical papers and find helpful links to more information on biosolids and related topics.

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Biosolids News

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