Code of Maine Rules › 01 - DEPARTMENT OF AGRICULTURE, CONSERVATION AND FORESTRY › 001 - AGRICULTURE - GENERAL › Chapter 560 - STANDARDS FOR COMPOST PRODUCTS › Section 001-560-4 - DEFINITIONS

Current through 2024-29, July 17, 2024
Compost
- Organic materials which have undergone
				  biological decomposition, and have been disinfected using composting or similar
				  technologies, and have been stabilized to a degree which is potentially
				  beneficial to plant growth.
Compost Grades
- Classifications of compost
				  materials based on nutrient content.
Some suggested grades are:
Nutrient grade compost
- A compost applied to
				  soil as a nutrient source. Nutrient levels are measurable and meet state's
				  minimum levels to qualify for fertilizer status( see Appendix). Conductivity is
				  greater than 4 mmhos/cm. It may contain appreciable lime equivalent.
Topsoil grade compost
- Compost or compost soil
				  mixture with organic content 4 - 40%, conductivity less than 2 mmhos/cm Used as
				  a soil replacement. Density is normally 1000-1600 lbs. per cubic yard.
Horticultural grade
- A compost with organic
				  matter greater than 25%. Conductivity is less than 1 mmhos/CM or mixed with
				  other materials to achieve this level. Density is normally less than 1000 lbs.
				  per cubic yard.
Composting
- The process by which biological
				  decomposition of organic materials is carried out under controlled aerobic
				  conditions, and which stabilizes the organic fraction into a material which can
				  easily and safely be stored, handled and used in an environmentally acceptable
				  manner. (The presence of anaerobic zones within the composting material will
				  not cause the process to be classified as something other than composting.)
				  Simple exposure of solid waste under uncontrolled conditions resulting in
				  natural decay is not composting.
Conductivity
- A measure of the soluble salts in
				  the soil. This is used as an overall indicator of the level of macro and micro
				  nutrients in the soil. Conductivity is measured in units of milli mhos per
				  centimeter (mmhos/cm).
D.E.P.
- The Department of Environmental
				  Protection including the Board of Environmental Protection and the
				  Commissioner.
Foreign Matter
- Sticks, stones, clods, roots,
				  glass, plastic, metal or other unwanted non-compostable materials that may be
				  present in compost.
Heavy Metals
- Those elements that are regulated
				  because of their potential for human, plant or animal toxicity including but
				  not limited to cadmium (Cd), copper (Cu), chromium (Cr), mercury (Hg), nickel
				  (Ni), lead (Pb) and zinc (Zn).
Loam
. Soil textural class that consists of a
				  mixture of sand (52% ), silt (28-50%), and clay (7-27%) measured on a weight
				  basis.
Mesophilic Stage
- The stage of the composting
				  process in which the rate of biological activity is high enough to maintain an
				  average pile temperature of at least 90 degrees F( 32(c). This stage follows
				  the thermophilic stage. It is in this stage that continued decomposition and
				  stabilization occurs.
Mulch
- A protective covering of various
				  substances, especially organic, placed around plants to prevent erosion,
				  compaction, evaporation of moisture, and freezing of roots and to control
				  weeds.
On-site mixing
- The practice of creating a soil
				  mixture by spreading compost on the surface of the site to be prepared and
				  tilling it into the top 3 to 6 inches of the existing soil. This practice would
				  be used primarily for establishing grass cover (or other crop) on large open
				  areas.
Pathogen
- An organism, chiefly a microorganism,
				  including viruses, bacteria, fungi, and all forms of animal parasites and
				  protozoa, capable of producing an infection or disease in a susceptible plant
				  or animal host.
PCB's
- Polychlorinated Biphenyls; A class of
				  chlorinated aromatic hydrocarbons representing a mixture of specific biphenyl
				  hydrocarbons which are thermally and chemically very stable.
PFRP - A Process to Further Reduce Pathogens
.
				  The D.E.P. considers the following compost processes to qualify as a
				  PFRP.
Method
MinimumTemperature
MinimumTime
Static Aerated Pile
55c
3
							 days*
Within Vessel
55c
3 days*
Windrow
55c
15 days*
Using the windrow composting method, there will be a minimum
				  of five turnings of the windrow during the high temperature period.
* Aerated static piles must remain in the pile for at least
				  21 days. All three approaches are required to retain compost in a curing pile
				  for at least 21 days following the active composting period.
Attaining a PFRP is essential for composts containing sludge
				  or septage if the compost is to be distributed to the public.
PSRP - A Process to Significantly Reduce
				  Pathogens
. The D.E.P. considers the following composting processes to
				  qualify as a PSRP.
Method
MinimumTemperature
MinimumTime
Static Aerated Pile
40c
5
							 days
Within Vessel
40c
5 days
Windrow
40c
5 days
For four hours during this period the temperature exceeds 55
				  degreesC.
Compost attaining a PSRP may be spread only on restricted
				  sites.
Putrefactive
- As result of the partial decay of
				  organic matter.
Saturated Paste Extract Method
- An approach for
				  analyzing compost materials in which water is added to the compost until it
				  just reaches saturation. This mixture is then allowed to sit for about 1 1/2
				  hours prior to performing tests. Conductivity, soluble nutrients and pH are
				  often tested using this approach.
Stabilized
- Means that the compost has at least
				  passed through the thermophilic stage, and that biological decomposition of the
				  organic materials has occurred to a sufficient degree that will allow
				  beneficial use. See Section 5.A. for a description of stability levels and the
				  methods for distinguishing them.
Static Aerated Pile Method
- A method of
				  composting in which materials are piled over perforated pipes or air ducts so
				  that the piles may be aerated using blowers to either force air up through or
				  draw air down through the compost mass.
Thermophilic Stage
- The stage of the composting
				  process in which the rate of biological activity is high enough to maintain an
				  average pile temperature of at least 130 degrees F(55C). This stage favors
				  decomposition by thermophilic (heat loving) bacteria. It is in this stage that
				  the most rapid destruction of pathogenic organisms occurs.
Topsoil
- Soil that consists of various mixtures
				  of sand, silt, clay and organic matter. Normally considered to be the nutrient
				  rich top layer of soil that supports plant growth.
Windrow Method
- A method of composting in
				  which materials are placed in long narrow piles (windrows) and aerated by
				  physically turning the materials.
Within-vessel Method
- A method of composting in
				  which compostable materials are placed in an enclosed drum, bin or other
				  vessel. Aeration is accomplished through rotation of the drum or through forced
				  aeration.