Rimrock
Renewables

The Rimrock Cattle Company Ltd. feedlot will continue to emit odours whether the proposed biodigester is built or not. Biodigestion is a proven technology that is currently the most advanced and effective option to reduce feedlot odours in the area.

How? The biodigester facility will capture odour-causing greenhouse gases (GHGs) from feedlot manure and, through a fully closed system, convert them to a usable energy resource called renewable natural gas (RNG). Today, those greenhouse gases are currently being released to the atmosphere. It will also help reduce feedlot operational odours by doubling the rate of livestock pen cleanouts and reducing the need for seasonal storage of raw manure at the feedlot. Overall, operation of the biodigester facility is predicted to result in an estimated 45% net reduction in feedlot odour. This 45% reduction in odours has been increased from the previously stated 42% reduction in odours due to optimized facility design changes. We are hopeful that as the facilities design continues to progress, predicted odour reduction will continue to increase. This estimated net decrease of 45% considers:

• 49% reduction in feedlot odours due to pen cleanout frequencies and manure stockpiling reductions.
• 4% addition and inclusion of potential odour sources introduced by the biodigester facility (this includes the organic food resources, manure blend building, solid digestate storage, and liquid digestate pond).
• This results in a net reduction of 45%.

This was determined through a comprehensive odour assessment study conducted by third-party experts.

We agree that community members should not be subjected to additional odours as a result of the biodigester facility, and we are committed to doing our part by designing the facility to mitigate potential odours and implementing best odour management practices at the facility.

The biodigester facility is being designed to mitigate potential odours, including odour containment and control measures such as:

• An enclosed manure blend building and, covered manure blend and organic food resources tanks.
• Anaerobic digester tanks that operate as a fully closed system.
• The biogas upgrader that removes odour-causing impurities from the biogas to produce pipeline quality RNG. This includes ammonia scrubbers as well as H2S and VOC active carbon filters which will collect odour-causing compounds and be properly disposed of without being released into the atmosphere.
• Covered tanks in the digestate separation building.
• Strategically designed soils berms between liquid digestate pond cells and around the site to protect it from prevailing winds to reduce emissions and evaporation.
• Ongoing assessments of odour reduction strategies throughout the facility lifecycle through a continuously improving odour management control plan.

A best odour management practices control plan for biodigester facility operations will include:

• Administrative controls like operator training and awareness, and the establishment of rigorous maintenance, inspection, and cleaning schedules.
• Odour management procedures for manure and organic food resources transportation, receiving and processing.
• Odour management procedures for digestate separation, staging and storage and the operation of the liquid digestate pond.
• Odour prevention and control measures that will be implemented during non-standard operating conditions (start-up, shut-down, maintenance and/or upset operating conditions).
• Routine monitoring of the performance of the anaerobic digesters and facility odour containment and control equipment as part of the facility inspection and maintenance program. For example, gas detectors (LEL, H2S and CO) will be used as an operational tool to adjust the feedstock schedule if undesired gasses are being produced.

Any conditions stipulated in the EPEA approval, if granted, related to air emissions limits, monitoring and reporting, along with any odour management requirements for the facility will be strictly adhered to. The EPEA approval and conditions will be publicly available.

Recognizing the proposed facility is in an area of high existing odours sources such as other feedlots, a meat processing facility, and a landfill, Rimrock intends to participate in a regional monitoring program as best determined in collaboration with other organizations and levels of government (for example, the Calgary Regional Airshed Zone portable monitoring station that was deployed in High River December 2022).

Importantly, community engagement and feedback will continue to be important to support the continuous improvement of regional odours.

The feedlot will continue to operate as part of the community whether the biodigester facility is constructed or not.

The feedlot is regulated by the Natural Resources Conservation Board (NRCB) under the Agricultural Operation Practices Act. The proposed Biodigester facility, if approved, will be constructed and operated by Rimrock Renewables under an EPEA approval issued by Alberta Environment and Protected Areas (AEPA). The NRCB and AEPA are two completely separate regulatory bodies. The existing NRCB permit regulating the feedlot will not be affected by the AEPA not issuing an approval.

The operation of the biodigester will not and cannot impact the existing feedlot permit or enable a feedlot expansion in any way.

The existing feedlot has been active since the 1980’s and operated by Rimrock Feeders since 2019. The NRCB will not allow for feedlot expansion beyond the permitted capacity of 35,000 beef finishers.

The biodigester would create a significant change in manure handling practices at the feedlot, streamlining manure handling practices and materially decrease feedlot odours.

Manure handling practices will change from long term stockpiling, to transporting manure to the adjacent on-farm biodigesters for processing. Manure will be transported using an internal connecting road from the feedlot to the biodigester facility, reducing public road traffic.

In response to community feedback about the digestate pond size and potential odour, Rimrock conducted multiple assessments and has identified opportunities to revise the pond design.

Individual assessments have identified two high-value opportunities to further reduce odour emissions:

1. Through liquid digestate reuse that decreases freshwater requirements and the size of the liquid digestate pond by approximately half.
2. A multi-celled liquid digestate pond to reduce odour emissions from the majority of the ponds surface and additional berms to protect it from prevailing winds.

It is important to note, potential odours may only be generated from the pond under certain conditions.

If the liquid digestate pond reaches higher surface temperatures during the warmest summer months, some residual volatile solids have the potential to breakdown and generate odours. Rimrock is proposing several operational controls to mitigate this potential, including reducing pond capacity during the summer, ensuring the pond is fully emptied at least twice a year, and utilizing proven process equipment to prevent odour generating volatile solids from entering the pond.

The composition of feedstock being used can also influence digestate odour characteristics.

Feedstock refers to all the materials processed by the biodigester, including manure and organic food resources. Predicted digestate odour characteristics will continue to be a key factor in selecting organic food resources suppliers, and although we do not yet have all these suppliers confirmed, we will continue to keep the community informed as the project progresses

We have also heard your concerns on how the pond will be operated to mitigate potential wildlife impacts.

Liquid digestate is a benign by-product of the anaerobic digestion process and the digestate pond has been designed as a semi-active system and with a reduced surface area, which is expected to reduce attraction of wildlife. That being said, we continue to review the potential need and appropriateness of deterrents, as part of detailed design. We are also committed to actively monitoring the digestate pond during operations to determine whether additional mitigations are required to reduce potential wildlife interactions with the pond.

We can confirm that unprocessed organic food resources will not be used or stored onsite.

Organics will be pre-processed offsite and delivered to the facility in fully enclosed trucks. Upon arrival, organic food resources will be transferred directly into fully enclosed organic food resource tanks, where they will be mixed with additional water and heated, before being sent through underground piping directly to the enclosed digester tanks. Deliveries will be scheduled based on operational needs, to avoid any onsite storage needs.

Organic food resources to be received and processed are still being determined.

All organic food resources accepted at the facility will be in accordance with the Memorandum of Understanding (MOU) among Alberta Environment and Sustainable Resources Development (AESRD), Alberta Agriculture and Rural Development (ARD), and the Natural Resources Conservation Board (NRCB), regarding On-Farm Storage and Land Application of Digestate.

Potential organic food resources that may be used at the facility include: fats, oils and greases, food processing residues, kitchen and market residues, horticultural residues, garden residues, energy crops, damaged/rejected crops, and crop residues.

We recognize that details regarding the source of organic food resources that will be processed in the facility are causing questions and concern.

As expected in a facility of this scope, certain details are determined prior to others. As the project develops and we continue to work alongside community, government and industry partners, we are committed to sharing new information. We will continue to update you with details about organic food resources as suppliers are confirmed.

This biodigester facility will turn waste into energy and will reduce greenhouse gas emissions. We consider this a huge win for the environment and has a high potential to improve odours for rural communities in close proximity to agricultural operations.

The biodigester facility will capture greenhouse gases from livestock manure and organic food resources and convert them to a usable energy resource called renewable natural gas (RNG). The biodigester facility will also create natural fertilizer (digestate) to offset synthetic fertilizer use. This is aligned with federal initiatives and will support the local agrifood industry by reducing the reliance on non-local synthetic fertilizers.

The most appropriate sourcing and efficient use of water for the biodigester facility was determined with environmental consideration, and adherence to licensing and regulatory guidelines.

All water will be sourced from the Highwood River, not groundwater. Rimrock obtained a water licence transfer from AEPA for the Highwood River under the Water Act. It is important to understand that this is not a new licence, but a transfer of an existing licence, and that 10% of the licence volume has not been transferred to Rimrock. This means the licence transfer actually decreases the allowable water withdrawals from the river.

Some ways that we are reducing water usage and protecting water resources:

• Water withdrawal volumes will be measured and tracked to ensure that all water used is under the licenced limit.
• Following the extensive assessment of liquid digestate reuse, the facility has the potential to reuse up to 25% of the liquid digestate upstream of the digestate pond in the facility process. This will represent a notable decrease in the freshwater needs for the facility.
• To prevent any impact to existing groundwater conditions Rimrock is implementing groundwater protection and monitoring (including secondary containment and groundwater monitoring systems), in accordance with Alberta Environment and Protected Area (AEPA) secondary containment guidelines.
• Any conditions stipulated in the EPEA approval, if granted, related to groundwater quality monitoring and reporting for the facility will be strictly adhered to. The EPEA approval and conditions will be publicly available.
• Rimrock will continue to study potential opportunities to decrease freshwater needs for the facility throughout the design process and will keep you informed of what we learn along the way.

Air emissions from the facility are designed to comply with ground-level ambient air quality.

An Air Quality Assessment using air dispersion modelling conducted in accordance with the Alberta Air Quality Model Guideline has been completed for the proposed facility. The maximum off-site ground-level concentrations for relevant contaminants of potential concern are predicted to comply with – in fact be well below – the Alberta Ambient Quality Objectives (AAAQO). Any conditions stipulated in the EPEA approval, if granted, related to air emissions limits and monitoring and reporting for the facility will be strictly adhered to. The EPEA approval and conditions will be publicly available.

This facility will generate valuable tax dollars for the county. We predict the construction activities will create over 200 construction positions throughout the length of the facility, as well as bring additional opportunities for local contractors, suppliers, restaurants, and service providers. We also expect a material regional odour reduction will have a positive effect on regional property values.