62-709.550. Classification of Compost  


Effective on Monday, February 15, 2010
  • 1(1) Compost shall be classified based on the type of waste processed, product maturity, the amount of foreign matter in the product, the particle size and organic matter content of the product, and the concentration of heavy metals as specified in the following sections. The following characteristics shall be used:

    51(a) Type of waste processed.

    561. Yard trash only.

    602. Manure or yard trash 65or vegetative waste 68with manure.

    703. Solid waste, other than only yard trash, 78vegetative waste 80or manure. 82This includes composts made from the addition of any animal byproducts.

    93(b) Product maturity.

    961. Mature.

    982. Semi-mature.

    1003. Fresh.

    102(c) Foreign matter content.

    1061. <= 2% dry weight.

    1072. > 2%, but <= 4% dry weight.

    1113. > 4%, but <= 10% dry weight.

    115(d) Particle size, using the screen size that the compost passed through. Organic matter content shall be associated with particle size.

    1361. Fine: <= 10mm, and an organic matter content of >138= 25%.

    1402. Medium: <= 15mm, and an organic matter content of >142= 30%.

    1443. Coarse: <= 25mm, and an organic matter content of >146= 35%.

    148(e) The codes in the following table for heavy metal concentrations shall be used in classifying the compost produced. The concentrations are expressed in mg/kg dry weight. In determining the appropriate classification code for parameter concentrations, if any one parameter falls in a higher concentration grouping, the code for that higher grouping will apply.

    202Concentration codes

    204Parameter205120622073                            2084

    209Cadmium< 1521015- < 3021130-100                            212> 100

    214Copper< 450215450- < 900216900-3,000                            218> 3,000

    221Lead< 500222500- < 1,0002231,000-1,500                            226> 1,500

    229Nickel< 5023050- < 100231100-500                            232> 500

    234Zinc< 900235900- < 1,8002361,800-10,000                            239> 10,000

    242(2) Compost shall be classified as follows.

    249(a) Type Y is compost made only from yard trash, which is mature or semi-mature, and is fine, medium or coarse. For such compost, a foreign matter content of less than 2% and a metal concentration equivalent to code 1 is assumed.

    291(b) Type YM is compost made from only 299vegetative waste, animal byproducts or 304manure, 305with or without 308yard trash, 310which is mature or semi-mature and is fine, medium or coarse. For such compost, a foreign matter content of less than 2% and a metal concentration equivalent to code 1 is assumed.

    342(c) Type A is compost made from solid waste, other than only yard trash, 356vegetative waste, animal byproducts or 361manure, which is mature and is fine. The foreign matter content shall be less than or equal to 2%, and the metal concentration shall fall under code 1. Further, it shall contain no foreign matter, such as glass or metal shards, of a size and shape that can cause injury.

    411(d) Type B is compost made from solid waste, other than only yard trash, 425vegetative waste, animal byproducts 429or manure, which is mature or semi-mature and is fine or medium. The foreign matter content shall be less than or equal to 4%, and the metal concentration shall fall under codes 1 or 2. Further, it shall contain no foreign matter, such as glass or metal shards, of a size and shape that can cause injury.

    486(e) Type C is compost made from solid waste, other than only yard trash, 500vegetative waste, animal byproducts 504or manure, which is mature or semi-mature and is fine, medium or coarse. The foreign matter content shall be less than or equal to 10%, and the metal concentration shall fall under codes 1, 2 or 3.

    541(f) Type D is compost made from solid waste, or from only yard trash, 555vegetative waste, animal byproducts 559or manure, which is fresh and is fine, medium or coarse. It shall have a foreign matter content of less than or equal to 10%, and the metal concentration shall fall under codes 1, 2 or 3. Foreign matter content and metal concentration is assumed for fresh compost made from only yard trash, 612vegetative waste, animal byproducts 616or manure.

    618(g) Type E is compost made from solid waste, other than only yard trash, 632vegetative waste, animal byproducts 636or manure, which has a metal concentration that falls under code 4.

    648(3) Compost maturity shall be determined as follows:

    656(a) Mature compost is a highly stabilized compost material that has been exposed to prolonged periods of decomposition. It will not reheat upon standing to greater than 20ºC above ambient temperature. It has beneficial use and can be used in direct contact with roots. The material should be brown to black in color. This level of maturity is indicated by a reduction of organic matter of greater than 60%.

    725(b) Semi-mature compost is compost material that is at the mesophilic stage. It will reheat upon standing to greater than 20ºC above ambient temperature. It has beneficial use, although direct contact with roots should be avoided. The material should be a light to dark brown in color. This level of maturity is indicated by a reduction of organic matter of greater than 40% but less than or equal to 60%.

    795(c) Fresh compost is compost material that has been through the thermophilic stage and has undergone partial decomposition. The material will reheat upon standing to greater than 20ºC above ambient temperature. It has beneficial use, but proper care is needed as further decomposition and stabilization will occur. The material should be similar in texture and color to the feed stock into the composting process. This level of maturity is indicated by a reduction of organic matter of greater than 20% but less than or equal to 40%.

    882Rulemaking 883Authority 884403.061, 885403.704, 886403.7043 FS. 888Law Implemented 890403.7043 FS. 892History–New 11-21-89, Formerly 17-709.550, 896Amended 2-15-10.

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