Â«Guide to Recovering and Composting Organics in Maine Maine Department of Environmental Protection Guide to Recovering and Composting Organics in ...Â»
the higher the potential for generation of nuisance odors and leachate generation. Type II residuals are sewage sludge, septage, and other residuals that may contain human pathogens. Type III residuals are petroleum contaminated soils and other residuals that may contain hazardous substances above risk based standards in 06-096 CMR 418, Appendix A.
(2) Facilities that compost domestic animal and poultry carcasses from routine events pursuant to the Maine Department of Agriculture, Food and Rural Resources Rules and Regulations Relating to Disease Control of Domestic Animals and Poultry, 01-001 CMR 211;
(3) Facilities that compost 10,000 cubic yards or less of animal manure per year;
NOTE: The facilities listed in section 1(B)(1) through (3) above should comply with the Department of Agriculture, Food and Rural Resourcesâ€™ Best Management Practices.
(4) Agricultural Composting Operations that, in any thirty (30) consecutive day period, compost a total of between five (5) and sixty (60) cubic yards of Type IB and IC residuals, and is operated in accordance with a Compost Management Plan approved by the Maine Department of Agriculture, Food and Rural Resources;
(5) Agricultural Composting Operations that compost any volume of Type IA, Type IB or Type IC waste provided that at least 70% of the finished compost product is used at appropriate agronomic rates on the farm that produced the compost within two (2) years after it is produced, and provided that the facility is operated in accordance with a Compost Management Plan approved by the Maine Department of Agriculture, Food and Rural Resources;
(6) Agricultural Composting Operations that use leaves as an amendment to compost manure provided that the facility is operated in accordance a Compost Management Plan approved by the Maine Department of Agriculture, Food and Rural Resources;
(7) Agricultural Composting Operations that compost offal provided that the facility is operated in accordance with a Compost Management Plan approved by the Maine Department of Agriculture, Food and Rural Resources;
(8) The composting of solid waste during a Department-supervised remediation, emergency response, or research project; and (9) Composting toilets as defined in the Maine Subsurface Wastewater Disposal Rules, 10CMR 241 (1004)(0).
What follows is an excerpt from these rules: 06-096, CMR 410 Section 6 śReduced Procedure For Select Compost Facilitiesâ€ť:
Applicability. This section applies to compost facilities that choose to follow the siting, A.
design and operational standards in this section and compost the following residuals:
If the conditions of this section will not be met, or if the applicant chooses to site, design or operate the facility in a manner that would not meet the standards of this section, then the applicant must submit an application to the Department for a license to develop and operate the compost facility under sections 2 through 4 of this Chapter.
Facilities licensed under this section are subject to the operating standards in section 4
of this Chapter.Reduced Procedure Siting and Design Standards. In addition to the general siting and B.
design standards contained in section 2 of this Chapter, a compost facility licensed
under this section must comply with the following standards:
Operating Requirements. In addition to the operating requirements of section 4 of this C.
Chapter, a compost facility licensed under this section is subject to the following additional operating requirements. Facilities licensed pursuant to 06-096 CMR 409(9) are subject to the operating requirements of section 4 of this Chapter, and the following
additional operating requirements:
Application Requirements. The applicant shall submit to the Department, on forms D.
developed by the Department, information sufficient to meet the standards and submissions requirements of 06-096 CMR 400(4) and the application requirements of section 3 of this Chapter. For outdoor compost facilities, instead of the site investigation information required by section 3(H) of this Chapter, the applicant may submit a report
from a Maine Certified Soil Scientist or other qualified individual that either:
(2) Identifies all major limitations to the proposed development presented by the soil characteristics and describes the techniques to be used to overcome the soil limitations identified in the soil survey.
V. Making Compost A. Setting Up the Composting Site Once the site has passed initial inspection by MEDEP, it is time to begin setting it up. The first consideration involves determining how large a footprint you will need to handle the volumes that you project. Remember, it is much easier to fill vacant space than it is to create more space at an already cramped site!
Determining the footprint is generally accomplished by developing a site-layout plan. The â€śOn-Farm Composting Manualâ€ť, published by the Northeast Regional Agricultural Engineering Service (NRAES- Bulletin 54), includes a very helpful chapter on site design and layout. A complete reference citation for this publication is included in the Appendix.
A site-layout plan should include sub-dividing the compost area into designated handling areas, listing facility design features and achieve/facilitate a logical flow of materials through the process at the facility. This plan will identify how many times the same material will have to be handled and how long it will occupy space in the different management areas on the site.
The following section describes a typical compost site-layout plan: (an illustration depicting
this site-layout immediately follows):
1. Receiving and Handling Area: This dedicated area allows for the coordinated delivery and handling of delivered feedstocks. Problem residuals may be isolated here. This separate area provides the operator with a first chance to control odors through good residual management (i.e., receiving putrescible materials, such as food scraps, on a bed of sawdust to help absorb leachate) or immediate mixing of seafood processing residuals with sawdust or horse manure.
2. Amendment Storage Area: This area allows for the receipt of and stockpiling of carbonaceous amendment, free from contamination with other feedstocks.
3. Mixing Area: This area allows for pre-determined, measured amounts of feedstocks to be accurately and thoroughly mixed, while also providing for odor and leachate control. This results in a thorough, heterogeneous mixture, which facilitates initiation of the active compost phase.
4. Composting Area: This is the area where the active composting begins and is generally the largest portion of the site. This area should be located centrally to the receiving/handling and mixing areas.
5. Curing Area: This area is designed for the aging and final maturation of compost piles or windrows that have completed the active compost phase. Curing is an essential step in the completion of the compost process, allowing natural progression and reduction in active microbial populations.
6. Waste Bypass Area: This designated location provides a centralized area for collection and storage of â€śnon-compostablesâ€ť for later disposal. Rejected loads of residuals may be staged here while waiting for pick-up. Common contaminants may
B. The Working Surface Upon determining the footprint of the compost area, a suitable work surface (pad) should be developed. A flat surface with a 2 to 4% grade (pitch) allows surface precipitation to quickly move off the pad, which prevents ponding and excessive moisture in compost windrows. There has been much discussion regarding the benefits/need of an asphalt or concrete pad over a traditional compact gravel or soil-based pad. Proponents of the asphalt pad state that it provides an impervious barrier, preventing leachate movement to groundwater. In addition, asphalt and concrete pads are very durable and can withstand years of use with very little maintenance. Soil and gravel pads, on the other hand, are prone to leachate infiltration and associated rutting, needing to be scraped and resurfaced on a yearly basis. For leaf and yard trimming composting, a compacted gravel pad is adequate, as very little leachate is usually generated as a result of composting these feedstocks.
However, if you are considering co-composting your leaf and yard trimmings with manure or food discards, you may wish to consider investing in an asphalt or concrete pad to avoid future leachate issues.
Compost facility design should include provisions for site drainage. Every attempt should be made to divert surface run-on (clean water) away from the compost area. This can usually be accomplished using upslope diversion ditches or berms. In areas where surrounding water sheds are significant, stone-lined waterways, and catch basins may be employed to intercept and channel surface water. Compost piles may be protected from precipitation by using pile coverings such as polar fleece to help shed excess water. Roofing over the compost operation is an option if the very high cost can be justified by the scale and goals of the program.
Runoff from the compost pad may be intercepted and treated by placing a vegetated â€ślevel lip spreaderâ€ť on the downslope edge of the composting surface. County Soil and Water Conservation Districts can provide advice on design and placement of level lip spreaders, or refer to the technical assistance list in the Appendix.
Facility access roads should also be designed and constructed with site drainage considerations in mind. Run-on from surrounding slopes can be diverted from the compost site simply by constructing a perimeter road perpendicular to the surrounding slopes.
C. Site Operations and Management
The general operations of a compost facility can be broken down into six separate steps:
ď‚ź recipe development ď‚ź feedstock preparation ď‚ź mixing and pile formation ď‚ź turning ď‚ź curing
1. Recipe Development The first step to beginning any compost effort is to determine what feedstocks are available for use and at what ratios they should be blended together. The easiest way to accomplish this is to develop a compost recipe. As a general rule, for leaf and yard trimmings, a recipe of three parts leaves to one part grass clippings will yield satisfactory results. If manure is added to the mixture, at least two additional parts leaves should be added for each part manure.
From the laboratory analysis, a final mixture (recipe) of feedstocks, which optimizes the chances for aerobic, thermophilic composting (sustained temperatures greater than 131 degrees Fahrenheit), can be developed.
In order for microbial colonization to occur, a recipe must contain appropriate amounts of carbon (microbial energy source), nitrogen (provides building blocks for microbial replication) and moisture (the medium that the microbes live in). In addition, there must be enough coarseness to the ingredients to promote natural diffusion of air throughout the final mixture. Otherwise, anaerobic conditions producing odors will occur.
The following conditions must be met, within the recipe, in order for optimal composting
conditions to occur:
For assistance in developing individual recipes, please refer to the technical assistance reference list that appears in the Appendix.
2. Feedstock Preparation Options Once the compost recipe has been determined, you should consider preparing the feedstocks for the mixing process. The amount of time invested in initial feedstock preparation directly affects the rate at which materials will compost. The goal is to create a feedstock that can be handled easily but will decompose quickly. The first processing step usually involves material sizing through grinding. Grinding feedstocks prior to mixing increases available surface area for microbial contact, provides for a better mixture among ingredients, and helps to speed decomposition by initiating the physical breakdown of ingredients. The purchase or lease of a grinder can be a costly investment, but grinding services can be hired in Maine on a per day basis. The charge for this service usually consists of the cost of transportation, set up, and the grinding. Grinding should be considered when making up the facilityâ€™s operations budget.
TM TM Morbark 1300â€” Commercially available tub grinder (photo by Morbark ) Once the feedstocks have been properly sized, the next consideration is moisture management. Ideally, a feedstock should contain approximately 50% to 60% water. Adding water to a dry feedstock will help optimize conditions for microbial colonization, whereas adding dry material to a saturated pile helps to create additional air spaces for pile oxygenation. To address this issue, the facility should have a water supply contingency plan, or if possible, have water directly available on site so that feedstocks and compost piles may be irrigated if necessary.
Guide to Recovering and Composting Organics in Maine Maine Department of Environmental Protection
3. Mixing and Pile Formation a. Mixing Next to recipe development, proper mixing is the single most important step determining success or failure of the compost operation. Obtaining a thorough, homogeneous mixture at the onset of the compost process, will ensure intimate contact between the carbon, nitrogen and moisture components of the pile, thereby reducing the potential for the formation of â€śdead spotsâ€ť. In addition, proper mixing allows for even air distribution throughout the pile, helping to promote aerobic composting.