Section Env-Sw 605.05 - Maturity Requirements(a) Except as provided in (b) below, compost shall be deemed mature when the final carbon-to-nitrogen (C:N) ratio is less than 25:1 and the compost meets or exceeds a maturity threshold for at least one test from group A and one test from group B as specified in Table 600-2 below, with test methods conducted in accordance with the "Test Method for Examination of Composting and Compost (TMECC)," April 2002, published by the US Composting Council, accessed as noted in Appendix B.(b) Compost distributed in bulk and used for agricultural crop production need not be mature as specified in (a) above, provided that the final carbon to nitrogen (C:N) ratio of the compost is less than 25:1 and the compost is otherwise suitable for the intended crop. Table 600-2: Compost Maturity Standards
| Test | Units | Maturity Threshold | Method |
Group A | Specific Oxygen Uptake | mg O2 per g organic matter per hour | <= 1.5 | TMECC 05.08-A |
CO2 Evolution | mg CO2 per g organic matter per day | <= 8 | TMECC 05.08-B |
Solvita® CO2 | Index Value | >= 5 | Manufacturer's SOP |
Dewar Self Heating Test | Temp. rise (°C) over ambient | <= 20 | TMECC 05.08-D |
Group B | Ammonium to Nitrate Ratio (NH4-N:NO3-N) | n/a | <= 3 | TMECC 05.02-C |
Total Ammonia (NH3-N) | ppm, dry basis | <= 500 | TMECC 04.02-C |
Solvita® NH3 | Index Value | >= 4 | Manufacturer's SOP |
Plant Trials | % of control | >= 80 | TMECC 05.05 |
N.H. Admin. Code § Env-Sw 605.05
#5172, eff 7-1-91; amd by #5295, eff 12-24-91; ss by #6535, INTERIM, eff 7-1-97, EXPIRES: 10-29-97; ss by #6619-B, eff 10-29-97; (See Revision Note at chapter heading for Env-Sw 600) ss by #8459, eff 10-28-05 (formerly Env-Wm 2305.05)
Amended byVolume XXXIV Number 24, Filed June 12, 2014, Proposed by #10596, Effective 7/1/2014, Expires7/1/2024.Amended by Volume XLII Number 14, Filed April 7, 2022, Proposed by #13358, Effective 4/1/2022, Expires 3/23/2032.