Code of Maine Rules › 01 - DEPARTMENT OF AGRICULTURE, CONSERVATION AND FORESTRY › 001 - AGRICULTURE - GENERAL › Chapter 560 - STANDARDS FOR COMPOST PRODUCTS › Section 001-560-6 - COMPOST PRODUCT SPECIFICATIONS

Current through 2024-29, July 17, 2024
6.A.
Compost Product - Topsoil/topsoil Substitute Class A
Nutrient grade or topsoil grade compost may be mixed with
				  mineral soil to create topsoil. By the appropriate blending, a topsoil of the
				  desired characteristics may be created. The mixture of the compost with mineral
				  soil to create topsoil will depend on nutrients, soluble salt levels and
				  organic matter content. See APPENDIX A for suggested mix ratios.
Use for Materials
- Any use for topsoil where
				  public is likely to be in direct contact with the material, e.g. seedbed for
				  slope stabilization, roadside revegetation, backfill for tree and shrub
				  planting, turf establishment on ballfields and playgrounds and other
				  landscaping applications.
6.A.1.
Characteristics to Consider
A good compost material for this purpose will be mature,
				  loose and friable, dark brown or black in color and low enough moisture content
				  to handle easily. Odors should be minimal. It will have virtually no human
				  pathogens. (For composts that contain municipal sludge, septage, or animal
				  manures, this can be achieved by meeting DEP's PFRP requirements. For areas
				  such as playgrounds and ballfields where children may frequently be in close
				  contact with the soil, extra precautions may be warranted. This could include
				  actions such as requiring suppliers to provide additional testing of the
				  material for Shigella sp. and/or E. coli if compost containing sludge or
				  septage is used.) It will also have few or no weeds, viable seeds, roots, or
				  rhizomes. Water holding capacity will normally be quite high in these products.
				  (Vote: Some seeds such as tomato seeds are very resistant and may survive even
				  though PFRP requirements have been met. Most weed seeds, however, will be
				  killed in the composting process.)
Suppliers should be required to provide a list of all the
				  ingredients in the original compost mix in the order of their relative
				  proportions on a weight basis. (i.e. all bulking agents, nitrogen sources, and
				  other additives, such as ash or stabilizers should be listed.)
In addition, suppliers of these materials should be asked to
				  provide assurances that they meet DEP heavy metal, PCB and dioxin limits and do
				  not contain levels of any chemicals that are harmful to plants or
				  humans.
6.A.2.
Measurements to Consider
Suppliers of compost products should be expected to provide
				  data based on laboratory analyses for each of the following
				  measurements:
pH
- Most composts fall into the 6.1 to 7.8
				  range. Some plantings require a pH outside this range. See the Horticultural
				  Recommendations for the type of plantings in question.
CaCO3 equivalency
- In cases where the pH of the
				  compost material is not close to neutral, ( <6.1 or >7.8 ) the supplier
				  should provide data on either its liming value or the amount of lime needed to
				  neutralize the product on a calcium carbonate equivalency basis. Some composts
				  with a higher pH have very little or no liming ability while others may have a
				  substantial liming effect. The desirability of having a liming capacity will
				  depend on the pH of the native soil and the requirements of the vegetation to
				  be established.
Coarseness
- Virtually all particles should pass
				  through a 3/8 inch sieve.
Nutrients
- The NPK levels for the compost
				  material should be provided by the supplier.
Soluble Salt Concentrations
- < 2 mmho/cm. in
				  the final mix (See Appendix A.)
Density/Weight per Cu Yd
- Compost would
				  normally be 1,000-1,300 lbs/cu yd at moisture content of 40 to 60%.
Moisture Content
- If the compost has a moisture
				  content between 40 and 60%, handling characteristics should be
				  acceptable.
Foreign Matter
- less than 2 percent foreign
				  matter on a dry weight basis.
6.A.3.
Mixing with Mineral Soil