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 2024-38, September 18, 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.
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.
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.
Organic Matter Content - When mixed with mineral soil, organic matter should be at least 3 percent of final mix.
Premixed vs. On-site mixing - For many applications such as establishing planting beds for ornamentals or backfill for tree planting, artificial topsoil should be premixed. On-site mixing will be practical when relatively small quantities of compost will be used on large relatively flat areas as is done with turf establishment. See Appendix A for suggested mix ratios.
6.B Compost Product - Topsoil/Topsoil Substitute Class B
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 Material - Any use for topsoil where public contact is minimal, e.g. seedbed for slope stabilization, roadside revegetation, tree and shrub planting, gravel pit reclamation, reseeding logging landings, final landfill cover.
A good compost material for this purpose will be mature or semimature, loose and friable, brown or black in color and low enough in moisture content to handle easily. It may have an odor as long as it is not foul or putrefactive. It will have few, if any, human pathogens. (For composts that contain municipal sludge, septage, or animal manures, this can be achieved by meeting DEP's PFRP requirements.) It will also have few or no weeds, viable seeds, roots, or rhizomes. Water holding capacity will normally be quite high in these products. (Note: 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.
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 - All particles should pass through a one inch sieve and 90% should pass through a half 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 Table 1.)
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 4 percent foreign matter on a dry weight basis.
Organic Matter Content - When mixed with mineral soil, organic matter should be at least 3 percent of final mix.
Premixed vs. On-site mixing - For many applications such as establishing planting beds for ornamentals or backfill for tree planting, artificial topsoil should be premixed. On-site mixing will be practical when relatively small quantities of compost will be used on large relatively flat areas as is done with turf establishment. See Appendix A for suggested mix ratios.
6.C. Compost Product - Topsoil/Topsoil Substitute Class C
Use for Material - Daily landfill cover
Compost may be mixed with mineral soil to create topsoil or may be used as produced. The mixture of the compost with mineral soil to create topsoil will depend on nutrients and soluble salt levels. See APPENDIX A for suggested mix ratios.
Landfill operators considering the use of materials other than soil for daily cover are required by D.E.P. Solid Waste Management Regulations to obtain D.E.P. approval before use.
A good compost material for this purpose may be mature or semimature. (Operators should consult with the D.E.P. Bureau of Solid Waste Management if they wish to use fresh compost.) It should also be loose and friable, and low enough in moisture content to handle easily. It may have an odor as long as it is not foul or Putrefactive. For composts that contain municipal sludge, or septage, DEP's PSRP requirements must be met.
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 exceed DEP heavy metal limits by no more than 200 percent, and that they meet the D.E.P. limits for dioxin and PCB's. Should materials exceed these levels, the D.E.P. Bureau of Solid Waste Management should be consulted prior to use.
Suppliers of compost products should be expected to provide data based on laboratory analyses for each of the following measurements:
pH - Composts falling anywhere in the 5.5 to 8.5 range should be acceptable.
Coarseness - All particles should be less than 12 inches in largest dimension. At least 80 percent should pass through a one-inch sieve.
Soluble Salt Concentrations - < 10 mmho/cm. in the final mix (See Table 1.)
Moisture Content - If the compost has a moisture content under 60%, handling characteristics should be acceptable.
Foreign Matter - less than 50 percent foreign matter on a dry weight basis.
Premixed vs. on-site mixing For daily landfill cover, artificial topsoil should be premixed. See Appendix A for suggested mix ratios.
6.D. Compost Product - Wetland Substrate
Use for Material - Reclamation of wetland areas.
Compost may be used as is, or mixed with naturally occurring soil to create a wetland substrate. By the appropriate blending, a soil of the desired characteristics may be created. The mixture to create the soil will depend on nutrients, soluble salt levels and organic matter content. Requirements for species to be established should be checked prior to determining the desired mixture.
A good compost material for this purpose will be mature or semimature, loose and friable, brown or black in color and low enough in moisture to handle easily. It may have an odor as long as it is not foul or putrefactive. It will have few, if any, human pathogens. (For composts that contain municipal sludge, septage, or animal manures, this can be achieved by meeting DEP's PFRP requirements.) It will also have few or no weeds, viable seeds, roots, or rhizomes. Water holding capacity will normally be quite high in these products. (Note: 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. If composts proposed for use in wetlands has been made from materials thought to contain dioxin, the D.E.P. Bureau of Solid Waste Management should be contacted for guidance prior to use.
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. Wetland soils normally have a pH of 3.6 to 4.4. To duplicate these soils, most composts would require pH adjustment. The pH of similar naturally occurring soils should be tested and substitute material should be adjusted to achieve the same pH level.
CaCO3 equivalency - For all composts being considered for use in wetland reclamation, the supplier should provide the CaCO3 equivalency. Some composts have very little or no liming ability while others may have a substantial liming effect. For this purpose, composts having little or no liming effect are preferred.
Coarseness - 85 - 95% should be less than 3 inches. Of the fraction less than 3 inches, the normal proportions passing different sieve sizes are as follows:
| Sieve Size | Percent |
| 4 (0.25 in) | 75 - 100 |
| 10 (0.10 in) | 60 - 100 |
| 40 (0.025 in) | 30 - 80 |
| 200 (0.005 in) | 0 - 30 |
A similar size distribution should be acceptable in most cases.
Nutrients - The total and soluble NPK levels for the compost material should be provided by the supplier.
Soluble Salt Concentrations - < 1 mmho/cm. in the final mix.
Density/Weight per Cu Yd - Organic soils would normally be between 635 and 1590 lbs/cu yd when moist.
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.
Organic Matter Content - When mixed with naturally occurring soil, organic matter should be 40 percent or more of final mix (if an organic substrate is required).
Premixed vs. on-site mixing - For most applications, artificial organic soil should be premixed. The practicality of on-site mixing may be limited by the ability of the site to support machinery and the depth of the organic layer to be established.
6.E. Compost Product - Mulch Class A
Use for Material - Soil stabilization on slopes.
A good compost material for this purpose will be mature, loose and friable, dark brown or black in color and low enough in moisture to handle easily. Unlike composts for other uses, mulch for slope stabilization should be fairly coarse and contain a high proportion of durable materials, such as wood chips. If used in areas where public contact is likely, odors should be minimal and there should be 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 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. (Note: 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.
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 applications require a pH outside this range.
CaCO3 equivalency - For all composts being considered for use as mulch, the supplier should provide the CaCO3 equivalency. Some composts have very little or no liming ability while others may have a substantial liming effect. For this purpose, composts having little or no liming effect are preferred.
Coarseness - Virtually all particles/pieces should pass through a 6 inch sieve but more than 50 percent should be retained by a 1 inch (#1) sieve and more than 75 percent should be retained by a 1/14 inch (#4) sieve.
Nutrients - The NPK levels for the compost material should be provided by the supplier. Lower nutrient content is desirable.
Soluble Salt Concentrations - < 1 mmho/cm. in the final mix.
Density/Weight per Cu Yd - Coarse compost would normally be 8001,300 lbs/cu yd at moisture content of 35 to 65%.
Moisture Content - If the compost has a moisture content between 35 and 65%, handling characteristics should be acceptable.
Foreign Matter - less than 2 percent foreign matter other than pieces of wood on a dry weight basis.
6.F. Compost Product - Mulch Class B
Use for Material - To conserve moisture; prevent surface compaction or crusting; reduce runoff; control weeds; and help establish plant cover.
A good compost material for this purpose will be mature, loose and friable, dark brown or black in color and low enough in moisture to handle easily. Compost based mulch for these purposes should contain a high proportion of durable materials, such as wood chips. If used in areas where public contact is likely, odors should be minimal and there should be 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 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. (Note: 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.
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 applications require a pH outside this range.
CaCO3 equivalency - For all composts being considered for use as mulch, the supplier should provide the CaCO3 equivalency. Some composts have very little or no liming ability while others may have a substantial liming effect. For this purpose, composts having little or no liming effect are preferred.
Coarseness - Virtually all particles/pieces should pass through a 6 inch sieve but more than 75 percent should be retained by a 1/14 inch (#(4) sieve.
Nutrients - The NPK levels for the compost material should be provided by the supplier. A low nutrient horticultural grade compost is desirable.
Soluble Salt Concentrations - conductivity < 1 mmho/cm. in the final mix.
Density/Weight per Cu Yd - Coarse compost would normally be 8001,300 lbs/cu yd at moisture content of 35 to 65%.
Moisture Content - If the compost has a moisture content between 35 and 65%, handling characteristics should be acceptable.
Foreign Matter - less than 2 percent foreign matter, other than pieces of wood on a dry weight basis.
TABLE 3. SUMMARY OF COMPOST ATTRIBUTES FOR DIFFERENT PURPOSES
| TOPSOIL | TOPSOIL | TOPSOIL | WETLAND | MULCH | MULCH | |
| ATTRIBUTE | CLASS A | CLASS B | CLASS C | SUBSTRATE | CLASS A | CLASS B |
| Purpose | High contact areas | Low contact areas | Landfill daily cover | Wetland restoration | Stabilize slopes | General Mulching needs |
| Stability | Mature | Mature or semi-mature or fresh | Mature, semi-mature | Mature or semi-mature | Mature | Mature |
| Odor | A | B | B | B | A,B | A,B |
| Pathogens | C,D | C,D | E | C | C,D | C,D |
| Heavy metals PCB's, dioxin | F | F | G | F | F | F |
| pH | 6.1-7.8 H | 6.1-7.8 H | 5.5-8.5 H | 3.6-4.4 H | 6.1-7.8 H | 6.1-7.8 H |
| Texture* | Sieve | %Pass | Sieve | %Pass | Sieve | %Pass | Sieve | %Pass | Sieve | %Pass | Sieve | %Pass |
| 3/8" | 100 | 1.0" | 100 | 12" | 100 | 3" | 85-90 | 6" | 100 | 6" | 100 | |
| 0.5" | 90 | 1" | 80 | #4 | 75-100 | 1" | 0-50 | #4 | 0-25 | |||
| #10 | 60-100 | #4 | 0-25 | |||||||||
| #40 | 30-80 | |||||||||||
| #200 | 0-30 |
| Soluble Sal content (mmhos/cm)t | 2 | 2 | 10 | 1 | 1 | 1 |
| Moisture(%) | 40-60 | 40-60 | 65 | 40-60 | 35-65 | 35-65 |
| Foreign matter (%) | 2 | 4 | 50 | 2 | 2 | 2 |
| Organic matter(%) | Y3 I | Y3 I | J | Y40 K | J,L | J,L |
* Note: Sieve numbers correspond to the following size openings:
| Sieve # | Opening Size |
| 4 | 0.25 inch |
| 10 | 0.10 inch |
| 40 | 0.025 inch |
| 200 | 0.005 inch |
CODES:
A Minimal odor in areas of high public contact.
B - Odors are allowed in areas of low public contact, but must not be foul or putrefactive.
C - Materials containing municipal sludge or septage must meet DEP's PFRP requirements.
D - Extra cautions may be desired where people will be in direct contact with material containing municipal sludge or septage (e.g. on playgrounds).
E - Materials containing municipal sludge or septage must meet DEP's PSRP requirements.
F - Meets DEP's requirements for heavy metals, PCB's, and dioxins as established in the Rules for Land Application of Sludge and Residuals. Chapter 567.
G - Exceeds the DEP limits for heavy metals by no more than 200% and meets the requirements for PCB's and dioxins as established in the Rules for Land Application of Sludge arid Residuals. Chapter 567.
H - Specific purposes nay require a pH outside this range. See horticultural recommendations for the specific use.
I - After mixing with mineral soil, the final topsoil mix should have at least 3% organic matter.
J - Organic matter % will be acceptable if other characteristics are net.
K - Acceptable organic matter levels will depend on the needs of the types of vegetation to be re-established.
L - High proportion of wood or other resistant material Is desirable.
