Appleton compost is derived from a 3.5 to 1 mixture (3.5 parts brush and leaves and 1 part Biosolids). Step 1 is mixing biosolids with the brush and leaves. The brush and leaves are collected from City of Appleton residents and stockpiled at the landfill until processing. Biosolids are transported from the AWWTP and immediately incorporated with brush and leaves at the predetermined ratios.
Once initial mixing is complete, the compost is put into windrows or elongated piles which are trapezoidal shaped approximately 14 feet wide at the base and 5 feet tall.
Windrows are then turned a minimum of five (5) times over an 8-12 week period to mix and homogenize materials. The turning process also provides air or oxygen to beneficial organisms that biologically stabilize or break down the material. This biological process (i.e. respiration) results in desired generation.
Temperatures of > 130° F are required for at least 15 days. The elevated temperature achieved through natural biological activity is not meant to sterilize the material but instead to destroy weed seeds and pathogens while promoting active beneficial populations of microorganisms. Turning also aids in reducing particle size of larger organic materials like ground brush and leaves.
Once monitoring and turning requirements are met the compost is "cured" and tested to verify that material meets high quality specifications. Screening removes unwanted or undesirable material like plastic bottles or metal that may come in with leaves or brush. Larger sticks or brush are also removed from the final material and reused in the composting process.
Final result is a dark, rich class "A" Exceptional Quality (EQ) compost which meets all Federal and State standards.