Compost
Compost shall be stable, humus-like material produced from the aerobic decomposition of organic feedstocks, composted and cured until maturity. Compost shall be certified to comply with mandatory Ontario Compost Quality Standards for Category ‘AA’ or ‘A’ Compost for concentrations of the 11 regulated metals, pathogens, foreign matter, maturity and labelling (OMOECC 2012) and Canadian Food and Inspection Agency (CFIA) regulations T-4-93 (CFIA 1997a) and T-4-120 (CFIA 1997b).
Compost shall also be certified to meet quality parameters recommended under the Compost Council of Canada’s Compost Quality Alliance (CQA) certification program (A&L Canada Laboratories 2004) through testing by an accredited soil laboratory (OMAFRA 2016):
| Parameter | Acceptable range |
|---|---|
| pH | 5.5 - 8.5 |
| Soluble Salts (EC) | < 5 mS/cm |
| Moisture Content | < 50% by weight |
| Organic matter | > 30% by dry weight |
| C/N ratio | 12 to 22 |
| Pathogens | OMOECC 2012 |
| Maturity | OMOECC 2012 |
| Particle size | 100% < 12.7 mm (1/2”) |
| Foreign Material | > 1.0% by dry weight > 3 mm < 0.5% plastic by dry weight no foreign matter > 25 mm per 500 mL no sharp foreign matter that could cause harm to humans or animals. |
| Arsenic | ≤ 13 mg/kg dry weight |
| Cadmium | ≤ 20 mg/kg dry weight |
| Chromium | ≤ 210 mg/kg dry weight</td |
| Cobalt | ≤ 34 mg/kg dry weight |
| Copper | ≤ 400 mg/kg dry weight |
| Lead | ≤ 150 mg/kg dry weight |
| Mercury | ≤ 0.8 mg/kg dry weight |
| Molybdenum | ≤ 5 mg/kg dry weight |
| Nickel | ≤ 62 mg/kg dry weight |
| Selenium | ≤ 2 mg/kg dry weight |
| Sodium, Percent Saturation | < 2% |
| Zinc | ≤ 700 mg/kg dry weight |
Where the custom calculated depth of compost amendment exceeds 7 centimetres (cm), or concentrations of any of the 11 regulated metals are near the maximum allowable limit, use Appendix 7 of Ontario Compost Quality Standards (OMOECC 2012) to determine the maximum application rate that will not exceed CFIA regulations for metals loading over a 45 year time period (CFIA 1997a).
The Contractor shall submit to the Owner’s Representative a 4L sample, with laboratory testing results or quality assurance documentation certifying that the material or product meets the requirements.