How to Compost Biosolids


Biosolids are treated organic materials left over from municipal waste treatment facilities--in layman's terms, human wastes. These treated human wastes are rich with nutrients such as nitrogen that can be applied to landscaping, gardening or agricultural plots to help improve soil conditions. Before adding biosolids to a vegetable plot, a gardener should further compost the product to remove trace amounts of pathogens that may remain in the material.

Step 1

Collect compost materials and sort them into nitrogen-filled organic green material and carbon-rich organic brown material. Green materials include biosolids, grass clippings and clover. Brown materials include wood chips, dead leaves, sawdust and straw.

Step 2

Run over compost materials such as straw, clover and grass clippings with a lawn mower to cut them to 1 inch or smaller. Smaller materials will compost faster.

Step 3

Form a compost pile of at least 3 cubic feet but no more than 5 cubic feet in diameter, using a shovel. Arrange organic green material and organic brown material in layers to form the pile. The brown material layer should be at least twice as thick as the green material layer. Your compost pile should be on dirt so that it can drain freely and should be in full sun.

Step 4

Wet down the compost pile with a garden hose until the compost is as damp as a wrung-out sponge. The internal temperature of the compost pile will begin to heat, killing the pathogens in the biosolids.

Step 5

Measure the compost pile's internal temperature daily, using an oven thermometer. The temperature should remain between 120 and 160 degrees Fahrenheit. Anytime the temperature approaches 160, do not stir the compost--allow it to cool. Stir the compost with a manure fork only when the internal temperature drops below 120 degrees Fahrenheit.

Step 6

Sift the compost with a compost sieve when the contents of the pile turn into fine organic loam. Remove any large pieces of undercomposed material and use them to start a new compost pile. Use the compost for containers, soil amendments or top-dressing garden soil.

Things You'll Need

  • Grass clippings
  • Clover
  • Wood chips
  • Dead leaves
  • Straw
  • Sawdust
  • Lawn mower
  • Shovel
  • Oven thermometer
  • Garden hose
  • Compost sieve
  • Manure fork


  • Washington State University Extension: Biosolids
  • Utah State University: Land Application of Biosolids
  • Washington State University Extension: Biosolids Management

Who Can Help

  • Colorado State University Extension: Choosing a Soil Amendment
Keywords: using biosolids, creating compost, sustainable landscaping

About this Author

Tracy S. Morris has been a freelance writer since 2000. She has published two novels and numerous online articles. Her work has appeared in national magazines and newspapers, including "Ferrets," "CatFancy," "Lexington Herald Leader" and "The Tulsa World."