Rule 3745-560-230 | Compost quality standards for class II composting facilities.
[Comment: For dates of non regulatory government publications, publications of recognized organizations and associations, and test methods referenced in this rule, see rule 3745-500-03 of the Administrative Code titled "Incorporation by reference."]
(A) The compost quality standards in this paragraph are applicable to all compost produced from yard waste, animal waste, agricultural plant materials, food scraps, dead animals, raw rendering material, and alternative materials. The owner or operator shall prepare and analyze the samples using the methods specified in tables 1 to 4 of this rule, or other methods authorized by the director pursuant to rule 3745-560-07 of the Administrative Code, to demonstrate that concentration limits or microbial counts are not exceeded for the parameters listed in tables 1 to 3 of this rule, and to ensure usage of compost product will be in accordance with accepted agricultural, silvicultural, or horticultural practices.
| Parameter | Concentration limit mg/kg dry weight | Preparation methods | Analytical methods | TMECC equivalent methods |
| Arsenic | 41 | SW-846 3050B or SW-846 3051A | SW-846 6010D or SW-846 6020B or SW-846 7010 | TMECC 04.06-As |
| Boron | See Table 4 | |||
| Cadmium | 35 | SW-846 3050B or SW-846 3051A | SW-846 6010D or SW-846 6020B or SW-846 7000B or SW-846 7010 | TMECC 04.06-Cd |
| Copper | 1500 | SW-846 3050B or SW-846 3051A | SW-846 6010D or SW-846 6020B or SW-846 7000B or SW-846 7010 | TMECC 04.06-Cu |
| Lead | 300 | SW-846 3050B or SW-846 3051A | SW-846 6010D or SW-846 6020C or SW-846 7000B or SW-846 7010 | TMECC 04.06-Pb |
| Mercury | 7.8 | SW-846 7471B | SW-846 7471B SW-846 6010D or SW-846 6020B or SW-846 7000B or SW-846 7010 | TMECC 04.06-Hg |
| Nickel | 420 | SW-846 3050B or SW-846 3051A | SW-846 6010D or SW-846 6020B or SW-846 7010 | TMECC 04.06-Ni |
| Selenium | 100 | SW-846 3050B or SW-846 3051A | SW-846 6010D or SW-846 6020B | TMECC 04.06-Se |
| Zinc | 2800 | SW-846 3050B or SW-846 3051A | SW-846 6010D or SW-846 6020B or SW-846 7000B or SW-846 7010 | TMECC 04.06-Zn |
| Parameter | Microbial count | Preparation method | Analytical method | TMECC equivalent method |
| Fecal coliform | Limit of less than 1000 Most Probable Number per gram of total solids (dry weight) (1000 MPN/GTS) | Standard methods part 9221E or part 9222D | Standard methods 9260B and either 9222D, 9221E or 9223 | TMECC 07.01-B |
| Salmonella spp. | Limit of less than 3 Most Probable Number per 4 grams of total solids (3MPN/4GTS) | Standard method part 9260B | Standard methods 9260B and either 9222D or 9221E, or Neogen Reveal® 2.0 | TMECC 07.02 |
| Parameter | Concentration limit mg/kg dry weight | Preparation method | Analytical method | TMECC Equivalent method |
| Inert matter | 1.0% by weight on No. 5 sieve (four mm screen) and no more than a fourth of this inert matter may be plastic | U.S. EPA 160.3 Methods for Chemical Analysis of Water and Wastes | Detailed below | TMECC 03.08 |
| Method for determining percent inert matter. Inert matter content shall be determined by passing a dried, weighed sample of not less than one hundred grams of compost through a "U.S. standard No. 5 sieve" (four millimeter). The material remaining on the screen shall be inspected and the inert matter separated and weighed. The weight of the inert matter divided by the total weight of the compost sample and multiplied by one hundred is the per cent dry weight of the inert matter content. |
| Parameter | Analytical method |
| Boron | TMECC 04.05-B or Preparation: SW-846 3050B or SW-846 3051A and Analytical: SW-846 6010D or SW-846 6020B |
| Maturity | TMECC 05.08-A Specific Oxygen Uptake Rate or TMECC 05.08-B Carbon Dioxide Evolution Rate or TMECC 05.08-C In-situ Oxygen Refresh Rate or TMECC 05.08-D Dewar Self-Heating Test or TMECC 05.08-E Solvita® Maturity Index or TMECC 05.08-F Biologically Available Carbon |
| pH | TMECC 04.11-A or North central regional (NCR) publication 221 or SW-846 9045D soil pH or ASTM D2976 |
| Salinity | TMECC 04.10 A or NCR publication 221 |
| Total nitrogen | AOAC 968.06 or TMECC 04.02-D or TMECC 04.02-A |
| Total organic carbon | SW-846 9060A or TMECC 04.01-A |
| Total phosphorus | TMECC 04.03-A or Preparation: SW-846 3050B or SW-846 3051A and Analytical: SW-846 6010D or SW-846 6020B |
| Total potassium | TMECC 04.04-A or Preparation: SW-846 3050B or SW-846 3051A and Analytical: SW-846 6010D or SW-846 6020B or SW-846 7000B |
[Comment:
Optimal levels of maturity will vary according to end-user application (note: check date of maturity test).
Optimal pH level will vary according to end-user application and will generally be in the 5.5 - 8.5 range.
Optimal levels of soluble salts will vary according to end-user applications. The optimal ranges for growing media (compost amended soil) is 0.5 to 4.5 millimho per centimeter.
Compost producers may provide pH and soluble salts information in product literature for the intended end-user application that reflect user industry standards.]
(B) Supplementary compost quality standards. Ohio EPA may request additional information or testing of feedstocks, bulking agents, additives, compost, or compost product from the owner or operator to ensure the standards are appropriately protective of public health, safety, or the environment.
(1) Upon written notification from Ohio EPA, the owner or operator shall provide information regarding the feedstocks, bulking agents, additives, compost, or compost product including but not limited to the following:
(a) The source of the feedstocks, bulking agents, and additives, including a description of the process used to generate the feedstocks, bulking agents, and additives.
(b) A description of the chemical and biological constituents and results for any testing requested by Ohio EPA.
(c) Any other information deemed necessary by Ohio EPA.
(2) Upon review of such additional information, the director may establish additional conditions or quality standards for the compost in writing to the owner or operator.
(C) Authorization for an alternative preparation or analytical testing method. Ohio EPA may approve and condition a request for alternative testing methods upon determination that the alternative methods ensure equivalent protection of public health, safety, and the environment. The owner or operator may submit a written request for approval of an alternative testing method that includes at a minimum the following information:
(1) The feedstocks, bulking agents, and additives accepted at the facility.
(2) A description or published references to the scientifically recognized preparation or analytical method that will provide equivalent or improved test results.
(3) A narrative of how the requested alternative testing method will ensure compliance with applicable quality standards.
(D) Ohio EPA may instruct the owner or operator to submit additional information upon review of a request generated in accordance with paragraph (C) of this rule.
Last updated December 3, 2025 at 7:40 AM
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