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) |