About Biosolids & Other Organic Residuals

biosolid n. (1990):

'"solid organic matter recovered from a sewage treatment process and used especially as fertilizer -- usually used in plural"

– Merriam-Webster’s Collegiate Dictionary, Tenth Edition

biosolids: plural noun:

organic matter recycled from sewage especially for use in agriculture

– New Oxford Dictionary of English, 1998

About Biosolids and Other Organic Residuals

Biosolids are the nutrient-rich organic byproducts resulting from wastewater treatment. Biosolids have been treated and tested and meet strict federal and state standards for use as fertilizers and soil amendments. Biosolids provide plant nutrients and organic matter to soils. They can also be used to produce energy through digestion and production of methane ("biogas") or drying and combustion, gasification, or pyrolysis.

Residuals are organic "waste" products that can be put to beneficial uses. Biosolids are one kind of residual. Other wastewater residuals commonly recycled in New England and eastern Canada include those generated at pulp and paper mills. Wood ash from electricity generators burning wood chips is another residual; it is used in farming as a replacement for lime and in composts.

See Frequently Asked Questions (FAQ).

See The Science of Biosolids Recycling.

Download a slideshow about how biosolids are made and used in New England and eastern Canada.