(a) Carbon-to-nitrogen ratio minimum of 15:1.
(b) Moisture content, range of 40% to 60%.
(c) At least 1 reading of a temperature greater than 130 degrees Fahrenheit after the
initiation of a batch with the temperature measured at a depth of 1 foot into the compost
once weekly. A temperature reading must be conducted twice per week for a rotating drum,
continuous flow, in-vessel system.
(d) The following conditions must be met for active composting:
(i) Composting temperature may remain in a range of 100 degrees Fahrenheit to 150
degrees Fahrenheit for several weeks.
(ii) Properly timed aeration, moisture alterations, or both.
(iii) Each batch of animal tissue compost must undergo a minimum of 3 heat cycles of
active composting before final utilization, unless the director determines fewer heat cycles
are necessary for the elimination of the virus of concern based on guidance from the United
States Department of Agriculture.
(iv) A static compost pile may be aerated passively, by periodic agitation, mixing or
turning, or by using forced aeration.
(13) An individual shall manage the composting process in compliance with the
guidelines described in the Michigan Animal Tissue Composting Operational Standards,
as adopted by reference in R 287.651a, and all of the following:
(a) The composting process must be managed in batches. Composting must involve
controlled active and curing phases, temperature-based aeration, and a planned end point
of not more than 2 years after the time of the first dead animal addition to a batch. Complete
curing is not required. Compost is considered finished based on its planned use as a soil
amendment or rooting medium, and its aesthetic acceptability. In the context of animal
tissue composting, finished and cured are different terms. Compost must be finished;
however, complete curing is not required.
(b) Dead animals must be added to the compost batch within 24 hours following death.
(c) Afterbirth may be stored in closed impervious containers and must be added to the
batch within 3 days after initiating container use.
(d) Initially, the compost pile or windrow must be constructed with a base of dry
absorbent bulking agent that is at least 1 foot deep before any dead animal is added for
composting. A base depth of 2 feet must be used for dead animals of greater than 600
pounds.
(e) Dead animals must not be placed in the pile or windrow closer than 6 inches to any
edge or wall.
(f) Dead animals must be covered by a minimum of 6 inches of bulking agent and not be
exposed.
(g) Pieces of hide remaining at the completion of curing must be removed and added to
a new active compost batch or be disposed of under section 21 of 1982 PA 239, MCL
287.671, before the compost may be sold, transferred, or applied to crop land. In emergency
composting situations, the Director may authorize the removal of unfinished compost to a
new site.
(h) Large bones of mature animals remaining at the completion of curing must be
crumbled during the mechanical spreading process, removed, and added to a new active
compost batch, or disposed of under section 21 of 1982 PA 239, MCL 287.671, before the
compost may be sold, transferred, or applied to crop land.
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