Compost Specifications

Compost Specifications
Link to this table

Parameter	Parameter Definition	Range
Source material/ Nutrient content	Typically biosolids/animal manure, source separated compostable materials or sorted yard wastes	Nitrogen: 0.5 – 3 Phosphorus: 0.5 – 1.5 Potassium: 0.5 – 1
Maturity	Level of completeness of the composting process	Seed emergence and seed vigor = minimum 80% relative to positive control
Stability	Biological activity in the composted material	CO2 evolution rate: < 8 milligrams CO2-C per grams organic matter per day
pH	Acidity/alkalinity	5.5 – 8.5
Soluble salts	The amount of soluble ions in a solution of compost and water	Varies widely according to source materials for compost, but should be < 10 deciSiemen per meter (millimhos per centimeter)
Organic matter	The amount of carbon-based materials	30-65% dry weight basis
Particle size	Size of particles	Pass through 1-inch screen or less
Biological contaminants	Pathogens (disease causing organisms) and weed seeds	Meet or exceed US EPA Class A standards, 40 CFR Section 503.32(2) levels
Physical contaminants	Man-made materials (like pieces of plastic or glass) that do not compose, also called ‘inerts’	< 1% dry weight basis
Trace metals	Elements that can be toxic to humans, animals or plants	Meet or exceed standards for Class I compost set in Minn.R. 7035.2836, Subp. 6, (A)