Section 250-RICR-140-05-8.14 - Anaerobic Digestion Design StandardsA. General All anaerobic digestion facilities shall meet all the requirements set forth in this Part in addition to the General Standards in § 1.5 of this Subchapter.
B. Provisions for Limiting Access 1. There shall be gates with locks at all entrances to the facility to prevent access except at times when authorized operating personnel are on duty;2. Fencing shall be required around the perimeter of the facility to prevent unauthorized access and illegal dumping at the site and to provide containment of wind-blown litter (if any).C. On-site Roads and Access Areas The facility shall be designed in a manner which prevents traffic backups and related traffic hazards on access roads serving the facility.
D. Emergency Access Provisions Access and on-site roads shall have adequate space and shall be maintained to allow the unobstructed movement of fire-fighting vehicles and other emergency vehicles, equipment and personnel to the operating area of the facility.
E. Unloading Area Design Features 1. The approach and unloading area shall be adequate in size and design to facilitate the rapid unloading of feedstock from vehicles and the unobstructed maneuvering of vehicles and other equipment;2. The unloading area shall be adequate in size and capacity to manage the projected volume of incoming feedstock;3. The unloading area shall be graded or other measures utilized to prevent ponding of leachate from the feedstock;4. The surface of the unloading area shall be constructed of impervious material, such as asphalt or concrete, capable of being cleaned by high-pressure water spray and equipped with drains, sumps or other means to collect liquids and leachate;5. The unloading area for waste in solid form shall be fully enclosed with a negative pressure air collection and treatment system, in order to prevent odor problems and any other potential nuisances. An alternate system for handling solids that will provide similar performance in preventing odor problems or other nuisances is also acceptable.6. Unloading of liquid wastes shall also be performed in a similar manner or shall be unloaded via hosing, piping, or similar means to enclosed structure(s) or vessel(s). The unloading area and the enclosed structure(s) or vessel(s) shall have secondary containment.F. Incoming Feedstock Storage Area Features 1. The facility shall have a storage area with capacity to handle any waste received and accepted during temporary equipment outages (e.g. disaster shutdown) and to accommodate temporary surges in delivery volume.2. All unprocessed feedstock storage areas shall be fully enclosed to prevent odors, control windblown dust and debris, prevent exposure to precipitation and collect liquids and leachate. The feedstock storage area shall comply with the requirements in § 8.14(L) of this Part.3. The storage area shall be graded so as to minimize ponding of leachate from the feedstock piles. The storage area shall be equipped with drains, sumps or other means to collect liquids and leachate.4. The surface of the storage area shall be constructed of impervious material, such as sealed asphalt or concrete, to minimize liquid release into the groundwater and to allow for cleaning with high-pressure water spray.5. The storage area design features in §§ 8.14(F)(2) through (4) of this Part shall also apply to amendments, if any, to be added to the feedstock.G. Design Provisions for Storage of Non-Processible and Non-Permitted Waste, Recyclables, Digestate, and Residues 1. The facility shall have the capacity for proper handling, storage and removal of non-processible waste and hazardous waste or other nonpermitted waste delivered to or generated by the facility.2. The facility shall have provisions for segregation and proper storage of recovered recyclables, if recyclables are accepted as part of the incoming feedstock and if recovered recyclables are not immediately removed offsite for recycling. Acceptable options include storing in an enclosed structure with a roof, in a covered container box or other equivalent option.3. The facility shall have provisions for segregation and proper storage of anaerobic digestion/digestate residues if such residues are not immediately re-processed or removed off-site for disposal. Storage shall be in a covered container box which is inside an enclosed structure with a roof in a designated storage area that complies with the requirements specified in § 8.14(L) of this Part. The covered container box shall be located on an impervious surface, such as sealed asphalt or concrete, to prevent leachate releases into groundwater. The Department will consider other equivalent options.4. The facility shall have the capacity for proper handling and storage of digestates, both solid and liquid (if applicable), prior to further processing of these materials on-site (if applicable) or prior to removal of these materials off-site for off-site processing, distribution, or disposal.H. Up-Front Processing Area Design Features (prior to anaerobic digestion) 1. If the facility performs any up-front processing of the incoming waste stream (i.e., removal of prohibited materials and non-processibles, recovery of recyclables, material size reduction or any other activities to improve the feed-stock prior to delivery to the anaerobic digester), then these activities shall be performed within the confines of an enclosed building to prevent odors, control windblown dust and debris, prevent exposure to precipitation and collect liquids and leachate. The feedstock processing area shall comply with the requirements in § 8.14(L) of this Part.2. Floor surfaces shall be constructed of an impervious material, such as asphalt or concrete, to prevent liquid releases into the groundwater under the site.I. Surface Water/Storm Water Management Design Provisions and Erosion Control/Sedimentation Prevention 1. The facility shall not be constructed or operated in a one hundred (100) year flood plain area unless provisions have been made to prevent encroachment of flood waters upon the facility and approval has been obtained from the Office of Water Resources;2. Storm water management systems shall be designed to control the water volume of a twenty-four (24) hour, twenty-five (25) year storm and to prevent run-on from entering the receiving, processing, composting, curing or storage areas;3. The design of the facility shall include erosion control measures, if needed.J. Leachate Management Design Provisions The facility shall have a leachate collection and removal system designed, constructed, maintained and operated to collect and remove leachate from the solids feedstock receiving and storage areas.
K. Fresh Air Controls A detailed discussion of the fresh air controls to be utilized within the operations building in order to prevent adverse conditions.
L. Odor Control Design Features 1. The anaerobic digestion facility shall be designed so that all operations are conducted within the confines of an enclosed building, structure, or vessel. These activities include receiving and preparing feedstock, anaerobic digestion, handling and management of digestate, composting and storage of finished compost (if applicable) and preparation and storage of fertilizer (if applicable). Odor control design measures shall include, but may not be limited to: a. The enclosed building, structure, and vessels shall maintain negative air pressure throughout the process or shall employ an approved alternate method;b. The enclosed building, structure, and vessels shall utilize an air collection and treatment system that employs scrubbing devices, filters, bio filters, or other approved alternatives prior to discharging to the atmospheric air.2. The applicant can petition the Department to conduct an activity outside the confines of an enclosed building, structure, or vessel if it can be demonstrated that the facility will not impact the surrounding community. At a minimum, the facility shall satisfy the following: a. The facility complies with the buffer and setback requirements in § 8.14(M) of this Part.b. The facility shall propose and implement additional measures to prevent and mitigate odors.M. Setback and Buffer Requirements 1. No feedstock, digestate, product or residuals shall be received (unloaded), stored, or processed on any well field or within one thousand (1000) feet of any private or public drinking water supply well or within the wellhead protection area delineated consistent with the wellhead protection program for a public well. If the owner or applicant seeks a variance from this requirement, then the Department will require demonstration that leachate (if any) from the anaerobic digestion facility will not impact on the water supply, under terms of the variance.2. No feedstock, digestate, product or residuals shall be received (unloaded), stored, or processed within the watershed of any surface water used as a public drinking water supply. If the owner or applicant seeks a variance from this requirement, then the Department will require demonstration that any run-off from the anaerobic digestion facility will not affect surface water quality, under terms of the variance.3. No feedstock, digestate, product or residuals shall be received (unloaded), stored, or processed within two hundred (200) feet of any body of surface water or freshwater wetland. If the owner or operator seeks a variance from this requirement, then the Department will require and the applicant shall demonstrate that any run-off from the anaerobic digestion facility will not significantly and adversely affect the surface water or wetlands, under terms of the variance.4. No feedstock, digestate, product or residuals shall be received (unloaded), stored, or processed within one hundred (100) feet of the facility's property line. If all operations of the anaerobic digestion facility are conducted within the confines of a building, structure, or vessel the operations shall not take place within three hundred (300) feet of any residence, place of business, or other private or public facilities occupied by humans (excluding the facility owner/operator's residences, offices, or other structures involved with the operation of the anaerobic digestion facility).5. If any activities related to the anaerobic digestion process occur outside, the operations shall not take place within five hundred (500) feet of any residence, place of business, or other private or public facilities occupied by humans (excluding the facility owner/operator's residences, offices, or other structures involved with the operation of the anaerobic digestion facility).N. Design Provisions for Fire and Explosion Prevention, Protection, Suppression and Control 1. The facility shall be designed and constructed to prevent and minimize the potential for fire or explosion;2. Facility design shall include provisions to monitor and mitigate explosive conditions and fire hazards;3. The facility shall contain a properly designed fire suppression system with sufficient capacity to adequately control a fire within the facility.4. The fire control and prevention plan shall be submitted to the local fire authority.O. Communication Systems The facility shall be designed with adequate communication systems to support normal and emergency operating conditions.
P. Back-up Power Supply The facility shall be designed with a back-up power supply or alternative method to prevent risks to human health and the environment and to prevent creation of nuisance conditions (e.g. off-site odor problems).
Q. Facility Support Equipment Requirement The facility shall have backup equipment on-site, or a contingency plan for essential items or those relating to critical issues, to support operations.
R. Storage Area for Replacement Parts and Equipment A replacement parts and equipment storage area shall be included in the facility.
250 R.I. Code R. 250-RICR-140-05-8.14
Amended effective4/22/2020