Code of Maine Rules
01 - DEPARTMENT OF AGRICULTURE, CONSERVATION AND FORESTRY
001 - AGRICULTURE - GENERAL
Chapter 211 - RULES FOR THE DISPOSAL OF ANIMAL CARCASSES
Section 001-211-11 - COMPOSTING REQUIREMENTS

Universal Citation: 01 ME Code Rules ยง 001-211-11

Current through 2024-38, September 18, 2024

Composting may be used as both a routine disposal method and as a catastrophic disposal method for animal carcasses and slaughterhouse waste (offal).

1. General Composting Requirements

A. Compost Media for Animal Carcass Composting

The media used for composting carcasses shall provide the conditions that will support hot aerobic composting. The composter should refer to Best Management Practices for Animal Carcass Composting 2011, Maine Department of Agriculture, Food, and Rural Resources, for guidance in selecting an appropriate compost medium.

B. Site Evaluation and Selection

Routine mortality compost sites shall be selected on the basis of the standards in Tables 3 through 7 located at the end of these rules. If site modifications or changes to setbacks are needed, this shall be done with the advice of a qualified professional (see definitions). Catastrophic compost sites shall be evaluated for suitability by a qualified professional on a case by case basis (see Appendix C for guidance in doing this).

C. Stormwater and Leachate Control

For all compost methods that may generate leachate or runoff, the surface upon which the compost materials will be placed shall have a slope that is no greater than 6% or less than 1.5%. The preferred slope is between 2% and 4% to allow rainfall to run off from the pad rather than collect on it. A vegetated buffer strip shall be maintained down slope from the pad to act as a filter for any water that leaves the pad. (See Table(8). Vehicle traffic shall be minimized in the vegetated buffer strip to reduce compaction of the soil. Additional storm water controls may be required on a case by case basis. Stormwater control measures shall be designed by the Natural Resources Conservation Service (NRCS), a private engineer, a certified soil scientist or other qualified professional.

D. Testing Requirements

Compost Products From a Disease Outbreak - Compost made from carcasses that resulted from a disease outbreak (such as foot and mouth disease or avian influenza) shall be tested for the survival of the specific disease agent involved.

E. Odor and Vector Attraction

Animal carcass compost sites shall be managed to minimize odors and the attraction of insects and other vectors. All carcasses or offal shall be covered with an appropriate compost medium as soon as possible. In no case shall carcasses remain uncovered for more than 24 hours when temperatures are 40° F or above. Offal shall be covered within 4 hours of delivery to the site.

F. Records

In addition to the records required for catastrophic disposal in Section 7.1.H, the following records shall be kept for catastrophic carcass compost operations:

(1). Location and date the piles were built;

(2). Temperatures. Temperature records shall be maintained if the compost product is to be distributed to the public; and a

(3). Record of disposition of compost - There shall be a record of the final disposition of each batch of compost produced.

These records shall be maintained for one year after the compost product has been distributed.

G. Failure to Reach Temperature Requirements

Compost that fails to meet the method-specific time and temperature requirements must be re-composted or spread on the producer's own fields or forest land.

H. Disposition of Product
(1). Compost produced from routine mortalities and offal may be distributed for general use by the public if it has met the time/temperature standards established for the specific compost system being used. The farm or regulated facility must retain records showing that the time/temperature standard was met. Compost may be spread on the regulated facility's own fields even if no temperature records are kept or do not indicate that the time/temperature standard has been met.

(2). The disposition of compost made from carcasses that result from a catastrophic event shall be determined on a case by case basis by the Commissioner.

(3). Compost produced from routine mortalities or offal shall be utilized or removed from the regulated facility's site within two years of its production.

2. Routine Carcass Disposal Compost Methods

Several methods are suitable for routine carcass or offal composting. These include:

A. University of Maryland Bin System (for poultry, small animals and poultry offal);

B. In-vessel compost systems (for poultry, small animals and animal parts);

C. Pre-condition and turn system (for any type of carcass or offal);

D. Turned windrow (for small carcasses or animal parts);

E. Aerated static pile system (may be used for poultry and small carcasses but limited usefulness due to the heterogeneous nature of the mix);

F. Static pile system (may be used for poultry and small carcasses but limited usefulness due to the heterogeneous nature of the mix); and

G. Other methods approved by the Commissioner.

3. Catastrophic Carcass Disposal Compost Methods

Methods that may be used for catastrophic carcass disposal include:

A. Turned windrow method (for offal, animal parts, poultry and small carcasses only);

B. Pre-condition and turn method (for any type of carcass or offal);

C. In-house windrow composting method (for certain poultry and small carcasses);

D. In-vessel compost systems;

E. Static or aerated static pile systems; and

F. Other methods approved by the Commissioner.

4. Requirements for Composting Systems

A. Siting Requirements for Compost Systems

Compost systems shall be sited so as to minimize negative health, environmental, and nuisance impacts. Standards for siting different types of compost systems vary depending on type and level of potential impacts. The standards for several common compost systems follow. Siting standards for other types of compost systems shall be determined by the Commissioner on a case by case basis.

Farms or other regulated facilities that have an existing carcass compost site that fails to meet the siting requirements at the time of the adoption of these rules shall contact the Department for assistance in evaluating the site and may seek a variance from the Commissioner.

(1). General Siting Requirements
(a). Significant sand and gravel aquifer sites shall not be used for uncontained composting operations;

(b). If the separation distances listed in the appropriate table do not exist naturally, engineering techniques such as loam liners, curtain drains, diversion ditches or adding fill may be used to establish these separation distances;

(c). Marshes, bogs, swamps and other areas with saturated soils shall not be used for composting sites;

(d). Composting sites shall be located as close to the source of carcasses as practical and in accordance with setback requirements in the appropriate tables. Whenever possible, the site should also be located so that the prevailing winds will not carry odors from the site to nearby neighbors;

(e). Surface water shall be diverted away from the compost facility;

(f). Compost sites shall be accessible to equipment at all times. If composting is to be done on natural soils, alternative sites or methods may need to be used during times when the soil is too wet to support traffic;

(g). Compost sites shall be designed and built so that no standing water will accumulate around or near the bins, vessels, piles or windrows. Leachate shall be directed to a suitable area to contain and/or treat the leachate; and

(h). Farm operations, individuals or other regulated facilities, who dispose of less than 500 lbs. of animal carcasses or offal per year, or one large animal or two medium size animals per year, by composting, are exempt from requirements (a) and (f) above. Section 8.2 contains special site selection requirements for small volumes.

(2). Siting Requirements for Maryland Bin Composting
(a). Setbacks and Separation Distances

Compost bins shall be set back minimum distances set forth in Table 4. In addition, animal carcasses shall be separated above bedrock, water tables and sand or gravel horizons in accordance with Table 5.

(b). Slope

The surface around the bins shall have a minimum slope of 1.5 percent and a maximum slope of 6 percent sloping away from the bins in all directions.

(3). Siting Requirements for Uncontained Carcass Compost Systems (turned windrow, pre-condition and turn, static pile and aerated static pile systems)
(a). Setbacks and Separation Distances

If the compost site is to be selected by the farmer or someone other than a qualified professional, the site shall meet the minimum distances set forth in Table 6. These setbacks may be modified by a qualified professional as long as adequate provisions or modifications are made to protect sensitive features. In addition, animal carcasses shall be separated above bedrock, water tables and sand or gravel horizons in accordance with Table 7.

(b). Slope

The composting surface shall have a minimum slope of 1.5 percent and a maximum slope of 6 percent. A slope between 2 and 4 percent is preferred.

(4). Siting Requirements for In-house Composting
(a). Setbacks and Separation Distances

Since the composting is done within the barn housing the poultry or livestock itself, no setbacks to sensitive features are required. In addition, since the compost piles or windrows will be inside a building, no separation distances from the water table, bedrock or sand and gravel layers are required.

(b). General Requirements
(i) In order to be suitable for in-house composting, the building must be a set up so that most of the floor can be accessed to build windrows.

(ii) Buildings to be used for in-house composting must be set up so that equipment necessary to manage the compost process may be operated in the building and may access all windrows to manage them.

(5). Siting Requirements for In-vessel (forage bag) Composting

This section applies to composting done inside the long tube-like plastic bags used to store forage. Requirements for other types of in-vessel compost systems shall be established by the Commissioner on a case by case basis.

(a). Setbacks and Separation Distances

The compost site shall meet the minimum distances set forth in Table 4. These setbacks may be modified by a qualified professional as long as adequate provisions or modifications are made to protect sensitive features. In addition, the containers holding animal carcasses shall be separated above bedrock, water tables, and sand or gravel horizons in accordance with Table 5. Separation distances may be modified by a qualified professional with permission of the Commissioner.

(b). Slope and Lay Out

The composting surface shall have a minimum slope of 1.5 percent and a maximum slope of 6 percent. A slope between 2 and 4 percent is preferred. A large open area with a relatively uniform slope is required to lay out the forage bags. The site should allow the forage bags to be placed so that they run up and down the slope and not trap water.

B. Operational Requirements for Compost Systems
(1) Operational Requirements for the University of Maryland Bin System

The University of Maryland Bin Composting System uses wooden or concrete block bins to compost poultry, poultry offal or other small carcasses. The composting is done in two active stages plus a curing stage. Carcasses shall be layered with straw and manure or other appropriate compost medium until the bin is full (see Section 11.1.A). The bin contents shall be allowed to compost for 7-10 days and then moved to a second bin. The moving shall be done so as to mix and loosen the material as much as possible.

After the material has been in the second bin for a minimum of 10 days, the material shall be moved to a curing pile where it shall be held for a minimum of 30 days. The moving shall be done so as to mix and loosen the material as much as possible.

(a). Bin Construction - The compost bins shall be built of decay-resistant wood or other durable materials. They shall be built on an impervious base and shall have a roof to keep out excess moisture

(b). Management of Maryland Bin Composters -The University of Maryland bin system shall be managed as follows:
(i). Temperature shall be monitored and recorded on a daily basis at least until the time/temperature standard has been met. Temperature readings shall be taken at a point near the center of the bin. The compost shall attain a minimum temperature of 131° F (55°(C) for a minimum of one day in Stage I and for a minimum of three days in Stage II. Batches that fail to meet this temperature requirement shall be incorporated into subsequent batches and re-composted or be spread on the owner's land;

(ii). At the end of each day that carcasses are placed in the bin, they shall be covered with manure and bulking agent to reduce odor, fly and vector problems;

(iii). To avoid fly and odor problems, carcasses shall be placed at least 6" from all sides of the compost bins;

(iv). Bin contents shall be moved or turned at least twice during the first 17 to 20 days of composting to assure thorough mixing and complete decomposition. After each turning, care shall be taken to make sure there is no soft tissue on the surface. Any soft tissue on the surface shall be covered immediately with manure, hay, compost or other appropriate cover material; and

(v). Composting shall be done using ingredients that promote hot aerobic composting (See Section 11.1.A ).

(2). General Operational Requirements for Systems Using Piles or Windrows (Note:The composter should refer to Best Management Practices for Animal Carcass Composting 2011, Maine Department of Agriculture, Food, and Rural Resources, for guidance in pile or windrow construction and management).
(a). Carcasses or offal shall be mixed with manure, bedding materials or other appropriate compost medium and formed into windrows or piles as soon as possible to minimize odor, insect and vector problems (See Section 11.1.A). Carcasses or offal shall make up no more than 20% of the mix by volume.

(b). The mixture shall have sufficient porosity such that it will easily allow air to be pushed or drawn through the pile or windrow (This is generally the case if the bulk density of the material is less than 1000 lbs per cubic yard).

(c). Preparation of carcasses: Large carcasses may be vented by puncturing or opening the abdomen, or may be cut into smaller pieces to facilitate the compost process. In the case of carcasses with highly contagious diseases, such as Foot and Mouth Disease, the Commissioner shall determine if carcasses are to be vented or cut on a case by case basis.

(d). Carcass or offal compost piles or windrows shall be visually checked on a daily basis during the first week after construction. Any exposed carcasses or tissues shall be covered with at least two feet of an appropriate compost material.

(e). Compost piles and windrows shall be constructed to be between four feet (4') and seven feet (7') in height and no more than fifteen feet (15') in width in order to allow for adequate aeration.

(f). Monitoring shall consist of daily checks on temperature and assessment of pile moisture. The thermometer used to check pile temperature shall have at least a three foot (3') probe and a scale that includes the range from 32°F to 212°F (0° to 100°(C).

(3). Operational Requirements for the Turned Windrow System

The minimum operational requirements for a turned windrow system are as follows:

(a). In the windrow composting method, temperature shall reach a minimum of 131° F (55°(C) for at least 15 days during the composting period. During the high temperature period there must be a minimum of five (5) turnings of the pile. Once this temperature requirement is met, the windrow shall be turned at least once per week. Once the temperature in the windrow drops below 110°F and does not increase after turning, the windrow may be placed in a curing pile;

Temperature monitoring shall be conducted in the following manner:

(i) A set of two temperature readings shall be taken at equally spaced intervals for every 30' of windrow length, but in no case shall there be less than two sets of readings taken for each windrow. One set of readings at each location shall consist of:

- a reading at the three foot depth or core of the pile; and

- a reading at one foot below the surface.

(ii) Temperature readings shall be taken in the same locations each day. An arithmetic average for each windrow may be calculated for each day's readings.

(b). There shall be at least 15 days that the average temperature at either the one foot or three foot depth for the day is 131° F (55°(C) or greater.

(4). Operational Requirements for the Static Pile System and the Aerated Static Pile System

The static pile and aerated static pile systems are essentially the same except that the aerated static piles are formed over perforated pipes or ducts that allow air to be introduced with a blower. The minimum operational requirements for the static pile and aerated static pile systems are as follows:

(a). The pile shall be maintained at a temperature of 131° F (55°(C) or greater for at least three (3) days at both the three foot and one foot depths in the pile. Detention time in the static pile or aerated static pile shall be at least 21 days, after which the pile may be dismantled and moved to curing;

(b). Temperature monitoring shall be conducted in the following manner:

A set of two temperature readings shall be taken, at equally spaced intervals, for every 30' of pile length, but in no case shall there be less than two sets of readings taken for each pile. The readings shall be taken from both of the following locations:

-Three feet or core of the pile; and

-One foot below the surface.

(c). Temperature readings shall be taken in the same locations each day. There shall be at least three (3) days at each depth and location that the temperature for the day is 131° F (55°C) or greater.

(5). General Operational Requirements for the Pre-condition and Turn Method
(a). Temperature shall be monitored on a daily basis and recorded, if the compost is to be distributed to the public. Temperatures shall be taken at the one foot and three foot depths in the pile. A set of two temperature readings shall be taken at equally spaced intervals for every 30' of windrow length, but in no case shall there be less than two sets of readings taken for each windrow. One set of readings at each location shall consist of:

- a reading at the three foot depth or core of the pile; and

- a reading at one foot below the surface.

Temperatures must be taken at the same locations each day. The compost shall attain a minimum temperature of 131° F (55°(C) at the three foot depth at each location for a minimum of three days in the pre-condition stage (Stage(I) or for a minimum of fifteen days at either depth during the turning stage (Stage II). The windrow shall be turned at least five times. Batches that fail to meet this temperature requirement shall be incorporated into subsequent batches and re-composted or spread on the farm or regulated facility's own land.

(b). Carcasses and/or offal shall be layered with an appropriate compost medium and formed into windrows or piles as soon as possible to minimize odor, fly and vector problems (See Section 11.1.A ).

(c). For all types of carcasses and offal, a layer of 18 to 24 inches of an appropriate compost medium shall be laid out on the composting surface as a base. Carcasses and/or offal shall be placed on this base in one or more layers depending on carcass or offal size. In all cases there shall be a minimum of two feet between the carcass and/or offal and the outside of the pile or windrow.

(d). Once all the carcasses or offal have been added to the pile, a minimum of two feet of the compost medium shall be placed over the carcasses or offal. No part of the carcass or offal may be less than two feet from the outside of the pile.

(e). Pre-condition and turn compost piles or windrows shall be constructed to be between four feet (4') and seven feet (7') in height depending on size and number of carcasses and no more than fifteen feet (15') in width in order to allow for adequate aeration.

(f) The pre-conditioning period length shall be sufficient to allow most of the soft tissue to be decomposed prior to the first turning of the windrow. The length of the pre-conditioning period will vary by size and type of carcass or offal. See Best Management Practices for Animal Carcass Composting 2011 Maine Department of Agriculture, Food, and Rural Resources for guidance in determining the appropriate pre-condition period length.

(6). Operational Requirements for In-house Composting

In-house composting may be done using any of the following methods: turned windrow; pre-condition and turn; static pile; or aerated static pile. The operational requirements shall be the same as the requirements laid out in the sections addressing these methods.

(7). Operational Requirements for In-vessel Composting

Because in-vessel systems vary widely, operational requirements shall be determined on a case by case basis. All systems shall meet the following minimum operational requirements:

(a). Carcasses or offal mixed with manure, bedding or other appropriate compost medium shall be placed in the vessel as soon as possible to minimize odor, fly and vector problems (See Section 11.1.A ). Carcasses shall make up no more than 20% of the mix by volume;

(b). Provisions shall be made to treat odors in the exhaust air leaving the vessel;

(c). The contents of the vessel shall be maintained at a temperature of 131° F (55°(C) or greater for at least three (3) days throughout the vessel. The composting mixture shall remain in the vessel until all soft tissue is gone but in no case shall it be retained for less than 21 days, after which the contents may be removed to a compost pile or placed in curing;

(d). Monitoring shall consist of daily checks on temperature, assessment of moisture, and visual checks on the vessel and associated equipment. The thermometers used to check vessel temperature will vary based on vessel configuration but shall have the capability of measuring temperatures in the range from 32° to 212° F (0° to 100°(C); and

(e). A set of temperature readings shall be taken at equally spaced intervals, depending on vessel configuration, sufficient to give a reasonably accurate representation of the temperature throughout the vessel.

5. Requirements for Catastrophic Composting Systems

A. Methods - Acceptable methods include turned windrow, static pile, aerated static pile, pre-condition and turn, in-house windrows and in-vessel. The preferred method for most situations is pre-condition and turn, especially for disease outbreaks. Authorization by the Commissioner is required before implementing a catastrophic carcass disposal composting process.

B. Siting Requirements - Although the standards used for siting routine compost operations may be used in an emergency, considerations may preclude the use of those standards, especially in the case of a highly contagious disease. For catastrophic events, the protocol outlined in Appendix C is recommended on a case by case basis.

C. Operational Requirements - Operational requirements for composting of catastrophic losses are the same as those for routine mortalities except that:
(1). The disposition of batches that fail to meet the time/temperature standards shall be determined by the Commissioner on a case by case basis;

(2). The compost medium shall be hot material prior to building compost piles if at all possible. Hot sludge based compost is recommended if available;

(3). Compost that results from diseased carcasses shall be tested for the survival of the disease organism prior to being used or distributed; and

(4). In addition to the items needed for routine compost records, the records of a catastrophic disposal compost operation shall also comply with Section 7.1.H. Records of Catastrophic Carcass Disposal Operation.

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