Biomass Geological Storage

1.0 Summary

This protocol (A document that describes how to quantitatively assess the net amount of CO₂ removed by a process. To Isometric, a Protocol is specific to a Project Proponent's process and comprised of Modules representing the Carbon Fluxes involved in the CDR process. A Protocol measures the full carbon impact of a process against the Baseline of it not occurring.) provides the requirements and procedures for the calculation of net CO₂e removal (The term used to represent the CO₂ taken out of the atmosphere as a result of a CDR process.) from the atmosphere via the injection of biomass into natural or engineered subsurface features or geologic formations (A body of similar rock type (e.g. color, grain size, mineral composition, texture) and a particular location in the stratigraphic column (vertical rock layers). Formations are large enough to be mappable on Earth's surface or traceable in the subsurface.) which may include, but are not limited to, reservoirs (A location where carbon is stored. This can be via physical barriers (such as geological formations) or through partitioning based on chemical or biological processes (such as mineralization or photosynthesis).), saline aquifers, caverns or mines, for long term sequestration of atmospheric CO₂. Biomass Geological Storage (Describes the addition of carbon dioxide removed from the atmosphere to a reservoir, which serves as its ultimate destination. This is also referred to as “sequestration”.) is considered a subsector of Biomass Carbon Removal and Storage (BiCRS) (A range of processes that use biogenic material to remove carbon dioxide (CO₂) from the atmosphere and store that CO₂ underground or in long-lived products (LLNL BiCRS Roadmap, 2020).). This protocol applies to biomass geological storage technologies or projects (An activity or process or group of activities or processes that alter the condition of a Baseline and leads to Removals or Reductions.), which typically consist of activities associated with threethe following sub-processes — biomass growth, processing of biomass prior to injection, biomass geologic  injection and storage.

The protocol accounts for quantification of the gross amount of CO₂ removed via injection of biomass into geologic formations, as well as the accounting for all net Greenhousegreenhouse Gasgas (GHG) emissions associated with the process, including growth, collection, use and alternate usecollection of the biomass feedstock (Raw material which is used for CO₂ Removal or GHG Reduction.), biomass injection process, and all transportation and embodied emissions (Life cycle GHG emissions associated with production of materials, transportation, and construction or other processes for goods or buildings.) emissions associated with the process, and emissions associated with leakage (The increase in GHG emissions outside the geographic or temporal boundary of a project that results from that project's activities.). The GHG AssessmentStatement (The process by which all emissions associated with a Project's Removal or Reduction process, including leakages, are accounted for.) is considered as a cradle-to-grave (​​Considering impacts at each stage of a product's life cycle, from the time natural resources are extracted from the ground and processed through each subsequent stage of manufacturing, transportation, product use, and ultimately, disposal.) analysis.

This protocol is developed to adhere to the requirements of ISO (A worldwide federation (NGO) of national standards bodies from more than 160 countries, one from each member country.) 14064-2: 2019 – Greenhouse Gases – Part 2: Specification with guidance at the project level for quantification, monitoring, and reporting of greenhouse gas (Those gaseous constituents of the atmosphere, both natural and anthropogenic (human-caused), that absorb and emit radiation at specific wavelengths within the spectrum of terrestrial radiation emitted by the Earth’s surface, by the atmosphere itself, and by clouds. This property causes the greenhouse effect, whereby heat is trapped in Earth’s atmosphere (CDR Primer, 2022).)emission reductions (Lowering future GHG releases from a specific entity.) or removal enhancements. The protocol ensures:

• consistent, accurate procedures are used to measure and monitor all aspects of the process required to enable accurate accounting of net CO₂e (The amount of CO₂ emissions that would cause the same integrated radiative forcing or temperature change, over a given time horizon, as an emitted amount of GHG or a mixture of GHGs. One common metric of CO₂e is the 100-year Global Warming Potential.) removals,
• consistent system boundaries and calculations are utilized to quantify net CO₂e removal for biomass geologic injection projects,
• requirements are met to ensure the CO₂e removals are additional (An evaluation of the likelihood that an intervention—for example, a CDR Project—causes a climate benefit above and beyond what would have happened in a no-intervention Baseline scenario.)
• evidence is provided and verified (A process for evaluating and confirming the net Removals and Reductions for a Project, using data and information collected from the Project and assessing conformity with the criteria set forth in the Isometric Standard and the Protocol by which it is governed. Verification must be completed by an Isometric approved third-party (VVB).) by independent third parties to support all net CO₂e removal claims

2.0 Sources and Reference Standards & Methodologies

Specific Standards (Standard physical constants as well as standard values set forth by bodies such as the National Institute of Standards and Technology (NIST) or others.) and protocols which are utilized as the foundation of this protocol and for which this protocol is intended to be fully compliant with are the following:

• Isometric Standard 1.0.0
• ISO 14064-2: 2019 – Greenhouse Gases – Part 2: Specification with guidance at the project level for quantification, monitoring, and reporting of greenhouse gas emission reductions or removal enhancements

Additional reference standards that inform the requirements and overall practices incorporated in this protocol include:

• ISO 14064-3: 2019 – Greenhouse Gases – Part 3: Specification with Guidance for the verification and validation of greenhouse gas statements
• ISO 14040: 2006 - Environmental Management - life cycle Assessment - Principles & Framework
• ISO 14044: 2006 - Environmental Management - life cycle Assessment - Requirements & Guidelines

3.0 Future Versions

This protocol was developed based on the current state of the art and current publicly available science regarding biomass processing and biomass geologic injection. Because biomass geologic storage is a novel approachcarbon to CO2dioxide removal (CDR) approach, with limited published literature, the protocol incorporates requirements that may be more stringent than some current relevant regulations for underground injection or other protocols related to biomass utilization for CO2 removalCDR.

This approach, notably when specifying requirements for demonstrating biomass geologic storage durability (The amount of time carbon removed from the atmosphere by an intervention – for example, a CDR project – is expected to reside in a given Reservoir, taking into account both physical risks and socioeconomic constructs (such as contracts) to protect the Reservoir in question.) or permanence, will likely be altered in future versions of the protocol as the stability of biomass in geologic formations becomes well demonstrated and documented, reversal (The escape of CO₂ to the atmosphere after it has been stored, and after a Credit has been Issued. A Reversal is classified as avoidable if a Project Proponent has influence or control over it and it likely could have been averted through application of reasonable risk mitigation measures. Any other Reversals will be classified as unavoidable.) risks are proven to be limited or non-existent, and the overall body of knowledge and data regarding all processes, from feedstock supply, to processing, and to permanent storage is significantly increased.

4.0 Applicability

This protocol applies to projects or processes which:

• utilize animal waste, biosolids, agricultural or forestry residues as eligible feedstocks in accordance with the framework set out in the Biomass Feedstock Accounting Module 1.2
• inject the biomass into natural or engineered geologic formations for long duration storage purposes via an underground injection well

This protocol applies to projects and associated operations that meet all of the following project conditions:

• the project provides a net-negative CO₂e impact (net CO₂e removal), as calculated in the GHG Statement, in compliance with Section 7 and with a cradle to grave GHG Assessment
• the biomass feedstock utilized is sustainably sourced¹
• the project does no net harm to the environment and society
• the project is considered additional (An evaluation of the likelihood that an intervention—for example, a CDR Project—causes a climate benefit above and beyond what would have happened in a no-intervention Baseline scenario.), in accordance with the requirements of Section 6.4
• the project provides long duration storage (>1000 yr estimated) of carbon in geologic formations
• the geologic storage site is located in the US
• the geologic storage site is properly permitted and has a current Class I or V UIC well permit². The site must be operated in compliance with current permits including those issued by the US EPA or U.S. States for underground injection control wells and specifically identify biomass or an equivalent type of injectant, as acceptable injectants under the permit³.

Projects that are explicitly NOT eligible include the following:

• Projects that utilize biomass injection as part of enhanced hydrocarbon recovery (EHR or EHR+) (Enhanced hydrocarbon recovery (EHR) is a tertiary hydrocarbon production technique or process where the physicochemical (physical and chemical) properties of the rock and/or the fluids are changed to enhance the recovery of hydrocarbon, typically by altering the chemical, biochemical, density, miscibility, interfacial tension (IFT)/surface tension (ST), viscosity and thermal properties to enable additional hydrocarbon production (SPE, 2023). EHR+ is the specific use of CO₂ injection for EHR where the CO₂ remains stored in the geologic formation permanently (IEA, 2015).)
• Projects that do not use sustainably sourced biomass feedstocks as detailed in Section 7.2.1.

5.0 Environmental and Social Safeguarding

The project must consider other environmental and social impacts and the project proponent (The organization that develops and/or has overall legal ownership or control of a Removal or Reduction Project.) must provide evidence that the project will do no net environmental or social harm, complying with Section 3.7 of the Isometric Standard.

In addtion to that outlined with the Isometric Standard, it must consider all aspects of the project from feedstock growth through injection and storage. At a minimum the project proponent must:

1. document activities conducted under the project which would require it to obtain environmental permits and provide a listing of all permits or construction approvals received or applied for and their current status and compliance history. This may include, but is not limited to, activities under the Resource Conservation & Recovery Act (RCRA), the U.S. EPA Underground Injection Control (UIC) program, the National Pollutant Discharge Elimination System (NPDES) program under the Clean Water Act (CWA), the Prevention of Significant Deterioration (PSD) program under the Clean Air Act (CAA), and other relevant environmental permits such as federal, state, county, or city permits for air, water or waste discharges;
2. document activities that would require the project proponent to obtain any drilling permits, access agreements, or any encroachment permits under county or city guidelines, or any federal, state, or local air, water, or restricted land use operating permits;
3. when agricultural residues are used, provide documentation of characterization of biomass in accordance with the Biomass Feedstock Accounting Module 1.2 to demonstrate impact on carbon and nutrient (nitrogen, phosphorus, potassium) removal;
4. provide documentation demonstrating whether the biomass is non-hazardous or hazardous, based on U.S. EPA RCRA requirements and testing completed by an accredited laboratory in accordance with U.S. EPA methods recommended in the Test Methods for Evaluating Solid Waste: Physical/Chemical Methods Compendium (SW-846)⁴ or equivalent, unless exempted by permit rule or standard. If the biomass is classified as hazardous:
   • evidence must be provided that all protocols for hazardous substance handling and management are being followed.
   • injection well permits must allow for hazardous waste injection and evidence that the permit conditions are being followed, must be provided.
   • containment within the targeted storage reservoir must be ensured and monitored, and all evidence provided.
5. demonstrate a risk assessment and mitigation plan for safeguarding working conditions, especially when it comes to safe handling and transportation of biomass feedstocks as well as workers operating the storage facility.

6.0 Relation to the Isometric Standard

The following topics are covered briefly in this protocol due to their inclusion in the Isometric Standard, which governs all Isometric protocols. See in-text references to the Isometric Standard for further guidance.

6.1 Project Design Document

For each specific project to be evaluated under this protocol, the project proponent must document project characteristics in a Project Design Document (The document that clearly outlines how a Project will generate rigorously quantifiable Additional high-quality Removals or Reductions.) (PDD) as outlined in Section 3.2 of the Isometric Standard. The PDD will form the basis for project validation (A systematic and independent process for evaluating the reasonableness of the assumptions, limitations and methods that support a Project and assessing whether the Project conforms to the criteria set forth in the Isometric Standard and the Protocol by which the Project is governed. Validation must be completed by an Isometric approved third-party (VVB).) and evaluation in accordance with this protocol, and must include consideration of processes unique to biomass such as:

• location information for biomass production, biomass injection, and the geologic storage formation location and area;
• conditions of biomass use prior to project initiation; and
• details on technologies, products, and services relevant to biomass processing, including production rates and volumes.

6.2 Validation and Verification

Projects must be validated and project net carbonCO₂e removals verified by an independent third party, consistent with the requirements described in this protocol, as well as in Section 4 of the Isometric Standard.

The Validation and Verification Body (VVB) (Third-party auditing organizations that are experts in their sector and used to determine if a project conforms to the rules, regulations, and standards set out by a governing body. A VVB must be approved by Isometric prior to conducting validation and verification.) must consider following requisite components:

1. Validate that feedstock adheres to the requirements listed in the Biomass Feedstock Accounting moduleModule 1.2.
2. Verify that storage sites adhere to the requirements listed in the relevant storage module.
3. Verify that the quantification approach and monitoring plan adheres to requirements of Section 7, including demonstration of required records.
4. Verify that the Environmental & Social Safeguards outlined in Section 5 are met.
5. Verify that the project is compliant with requirements outlined in the Isometric Standard.

6.2.1 Verification Materiality

The threshold for Materiality (An acceptable difference between reported Removals/emissions or Reductions/emissions and what an auditor determines is the actual Removal/emissions or Reduction/emissions.), considering the totality of all omissions, errors and mis-statements, is 5%, in accordance with Section 4.3 of the Isometric Standard.

Verifiers should also verify the documentation of uncertainty (A lack of knowledge of the exact amount of CO₂ removed by a particular process, Uncertainty may be quantified using probability distributions, confidence intervals, or variance estimates.) of the GHG Statement (A document submitted alongside Claimed Removals and/or Reductions that details the calculations associated with a Removal or Reduction, including the Project's emissions, Removals, Reductions and Leakages, presented together in net metric tonnes of CO₂e per Removal or Reduction.) as required by Section 2.5.7 of the Isometric Standard. Qualitative materiality issues may also be identified and documented, such as ⁵:

• control issues that erode the verifier’s confidence in the reported data;
• poorly managed documented information;
• difficulty in locating requested information;
• noncompliance with regulations indirectly related to GHG emissions, removals or storage

6.2.2 Site Visits

Project validation and verification must incorporate site visits to project facilities in accordance with the requirements of ISO 14064-3, 6.1.4.2, including, at a minimum, site visits during validation and initial verification to the biomass processing site and the biomass injection site. Validators should, whenever possible, observe operation of the biomass processing and injection to ensure full documentation of process inputs and outputs through visual observation.

A site visit must occur at least once every 2 years at each location.

6.2.3 Verifier Qualifications & Requirements

Verifiers and validators must comply with the requirements defined in Section 4 of the Isometric Standard. In addition, teams must maintain and demonstrate expertise associated with the specific technologies of interest, including biomass growth or production, biomass processing, biomass production and geologic storage.

Competency must be demonstrated through the below relevant sectoral scope accreditations listed below, orbased throughon demonstrationIAF ofMD relevant14 experience,and in accordance with Isometric's VVB policy:

• Storage - Carbon Capture and Storage of CO₂ in Geological Formations

6.3 Ownership

Carbon removalCDR via biomass injection is often a result of a multi-step process (such as biomass growth, harvesting, transport, processing, injection, and storage), with activities in each step managed and operated by a different operator, company, or owner. When there are multiple parties involved in the process (e.g., forestry owner or injection site operator), and to avoid double counting (Improperly allocating the same Removal or Reduction from a Project Proponent more than once to multiple Buyers.) of carbonnet CO₂e removals, a single project proponent must be specified contractually as the sole owner of the carbon removalsCredits. Contracts must comply with all requirements defined in Section 3.1 of the Isometric Standard.

6.4 Additionality

The Project Proponent must be able to demonstrate additionality through compliance with Section 2.5.3 of the Isometric Standard. The baseline (A set of data describing pre-intervention or control conditions to be used as a reference scenario for comparison.) scenario and counterfactual (An assessment of what would have happened in the absence of a particular intervention – i.e., assuming the Baseline scenario.) scenarios and baselines (A set of data describing pre-intervention or control conditions to be used as a reference scenario for comparison.)  utilized to assess additionality must be project-specific, and are described in Section 7.2 of this Protocol.

Additionality determinations should be reviewed and completed every two years, at a minimum, or whenever project operating conditions change significantly, such as the following:

• regulatory requirements or other legal obligations for project implementation change or new requirements are implemented;
• project financials indicate carbon finance (Resources provided to projects that are generating, or are expected to generate, greenhouse gas (GHG) Emission Reductions or Removals.) is no longer required, potentially due to, for example:
  • increased tipping fees for waste feedstocks;
  • sale of co-products that make the business viable without carbon finance;
  • reduced rates for capital access.

Any review and change in the determination of additionality willshall not affect previously issued (Credits are issued to the Credit Accountavailability of acarbon Project Proponent with whom Isometric has a Validated Protocol after an Order for Verificationfinance and Creditcarbon Issuance services from a Buyer and once a Verified Removal or Reduction has taken place.)credits (A publicly visible uniquely identifiable Credit Certificate Issued by a Registry that gives the owner of the Credit the right to account for one net metric tonne of Verified CO₂e Removal or Reduction. In the case of this Standard, the net tonne of CO₂e Removal or Reduction comes from a Project Validated against a Certified Protocol.) for the current or past crediting periods (The period of time over which a Project Design Document is valid, and over which Removals or Reductions may be Verified, resulting in Issued Credits.), but, if the review indicates the project has become non-additional, this willshall make the project ineligible for future credits⁶.

6.5 Uncertainty

The uncertainty in the overall estimate of the net CO₂e removal as a result of the project must be accounted for. The total net CO₂e removed, CO2e([math: CO_2e_{Removal}]), n for a specific batch ([math: n]) must be conservatively (Purposefully erring on the side of caution under conditions of Uncertainty by choosing input parameter values that will result in a lower net CO₂ Removal or GHG Reduction than if using the median input values. This is done to increase the likelihood that a given Removal or Reduction calculation is an underestimation rather than an overestimation.) determined, givingbased highon confidence in resulting removals. Projects must comply withthe requirements outlined in Section 2.5.7 of the Isometric Standard.

6.5.1 Reporting of uncertainty

Projects must report a list of all input variables used in the net CO₂e removal calculation and their uncertainties, including:

• emission factors (An estimate of the emissions intensity per unit of an activity.) utilized, as published in public and other databases used;
• values of measured parameters from process instrumentation, such as truck weights from weigh scales, flow rates from flow meters, electricity usage from utility power meters, and other similar equipment;
• laboratory analyses, including analysis of carbon content of injected biomass.

The uncertainty information should at least include the minimum and maximum values of a variable. More detailed uncertainty information should be provided if available, as outlined in Section 2.5.7 of the Isometric Standard.

In addition, a sensitivity analysis (An analysis of how much different components in a Model contribute to the overall Uncertainty.) that demonstrates the impact of each input parameter’s uncertainty on the final net CO₂e uncertainty must be provided. Details of the sensitivity analysis method must be provided sosuch that a third party can reproduce the results can be re-created. ParametersInput variables may be omitted from aan full uncertaintyuncertanty analysis if athey Sensitivity Analysis can demonstrate that the parameter contributescontribute to a < 1% change in Removalthe net CO₂e removal. For all other parameters, information about Uncertaintyuncertainty must be specified.

6.6 Data sharing

In accordance with the Isometric Standard, all evidence and data related to the underlying quantification of CO₂₂e removal will be available to the public through Isometric's platform (A community resource where Project Proponents publish and visualize their early processes, Removal and Reduction data and Protocols – enabling the scientific community to share feedback and advice.). That includes:

• Project Design Document
• GHG Statement (A document submitted alongside Claimed Removals and/or Reductions that details the calculations associated with a Removal or Reduction, including the Project's emissions, Removals, Reductions and Leakages, presented together in net metric tonnes of CO₂e per Removal or Reduction.)
• Measurements taken
• Emission factors used
• Scientific literature used

The project proponent can request certain information to be restricted (only available to authorized buyers (An entity that purchases Removals or Reductions, often with the purpose of Retiring Credits to make a Removal or Reduction claim.), the Registry (A database that holds information on Verified Removals and Reductions based on Protocols. Registries Issue Credits, and track their ownership and Retirement.) and VVB) where it is subject to confidentiality. This includes emissions factors from licensed databases. However, thatall does not apply to anyother numerical data produced or used as part of the quantification of net CO₂₂e removedremoval will be made available.

7.0 Quantification of net CO₂e removal

7.1 System Boundary & GHG Emissions Scope

The scope of this protocol includes GHG sources, sinks (Any process, activity, or mechanism that removes a greenhouse gas, a precursor to a greenhouse gas, or an aerosol from the cradle-to-graveatmosphere.), GHGand assessmentreservoirs of all emissions(SSRs) associated with the following aspects of a biomass injection CDR project for CO2e removal. A cradle-to-grave GHG Statement must be prepared, whichencompassing mustthe accountGHG foremissions relating to the following activities:

• Biomass production (growth and harvesting)
  • Replacement emissions (Any emissions that occur to compensate for biomass that was previously serving another purpose and is now being used for carbon removal or GHG reduction. For example, if agricultural waste was previously left on a field to decompose - fertilizer production to replace those nutrients need to be accounted for.)
  • Direct and indirect land use changes, if applicable
  • Counterfactual storage
• Biomass transport
• Biomass processing prior to injection
• Biomass injection
  • SequestrationMonitoring (including carbon content monitoring, reversals monitoring
• Embodied emissions associated with each process above, suchlab as for manufacture processing and shipping of processing equipment.surveys)

It should be noted that the physical and system boundaries for the biomass injection and storage site should include the following subprocess:

• Delivery of biomass to injection site (injection facility gate)
• Injection facility (including any surface processing or preparation of biomass and injectants, injection system, and balance of plant or auxiliary systems)
• Monitoring wells and any above ground monitoring systems or devices
• The limits of the geologic storage reservoir (vertical and lateral)
• Embodied emissions associated with each activity and process, such as for manufacture and shipping of process equipment and for consumables used

Emissions for processes within the system boundary must include all GHG sources, sinks (Any process, activity, or mechanism that removes a greenhouse gas, a precursor to a greenhouse gas, or an aerosol from the atmosphere.), and reservoirsSSRs from the construction or manufacturing of each physical site and associated equipment, closure and disposal of each site and associated equipment, and operation of each process (biomass production, biomass injection), to include embodied emissions of equipment consumables in the process.

Note thatThe thisProject protocolProponent doesis notresponsible requirefor inclusionidentifying all sources of emissions resultingdirectly fromor ancillary activities not directlyindirectly related to project operationsactivities.

Any emissions from sub-processes or process changes that would not have taken place without the involvement of the CDR process, such as subsequent transportation and refining, must be fully considered in the system boundary. This allows for accurate consideration of additional, incremental emissions induced by the CDR process.

Ancillary activities (such as supplementary research and development activities, and corporate administrative activities) andthat anyare associated facilitieswith a project but are not directly or indirectly related to the issuance of Credits can be excluded from the system boundary. 

In addition, biomass processing will typically produce co-products,. this protocol does not account for the production and use of those co-products and assigns allAll emissions associated with the entire system where biomass processing takes place must be fully allocated to the biomassCDR that is injected as a conservative estimateprocess.

Carbon fluxes (The amountsystem ofboundary carbonfor exchangedGHG betweenaccounting twomust orinclude moreall ReservoirsSSRs overcontrolled a period of time.)by and associatedrelated GHG emissions (positive and negative (Occur when a Sink – created or enhanced by human activity – removes greenhouse gasses from the atmosphere (CDR Primer, 2022).)) fromto the project may derive from, including but are not limited to, the following sourcesSSRs in Table 1:.

Table 1

All GHGs must be quantified and converted to CO₂e in the GHG Statement using the 100-yr Global Warming Potential (GWP) for the GHG of interest, based on the most recent volume of the IPCC Assessment Report (currently the Sixth Assessment Report).

7.2 Baseline

The projectbaseline proponentscenario mustfor usebiomass geological storage projects assumes the frameworkactivities providedassociated in Section 2.5.2 ofwith the Isometric Standard as well as in this protocol to establish their GHG baseline. Development of a GHG baseline allows consistent comparison of a project activities’do effectsnot totake place and any existingassociated orinfrastructure alternativeis projects,not activities,built.

The orcounterfactual technologiesis thatthe wouldCO₂ be consideredstored in the absencebiomass of a proposed project.

7.2.1 Biomass Feedstock Accounting

The GHG baseline must be developed for the specific project and consider specific alternative uses of biomassfeedstock that would have occurredremained durably stored in the biomass in the absence of the project. TheThis GHGis baselineknown mustas alsoineligible considerbiomass, given that the baselineCO₂ relativestored would have remained stored in the biomass in the absence of the CDR project and is therefore not eligible to eachcount feedstocktowards used,Crediting. ifThe Biomass Feedstock Accounting Module 1.2 sets out requirements for establishing ineligible biomass as part of the projectCounterfactual utilizesStorage multipleEligibility feedstockcriteria. typesThe Biomass Feedstock Accounting Module 1.2 includes details for quantification of [math: CO_2e_{Counterfactual}].

7.3 Net CDRCO₂e (Activities that remove carbon dioxide (CO₂) from the atmosphere and store it in products or geological, terrestrial, and oceanic Reservoirs. CDR includes the enhancement of biological or geochemical sinks and direct air capture (DAC) and storage, but excludes natural CO₂ uptake not directly caused by human intervention.)Removal Calculation

7.3.1 Calculation Approach

The biomass injection process is typically operated on a batch basis, whereby a ‘Production Batch’, [math: p], is produced from a 'Production Process', defined as a process using a single type of biomass feedstock, often of a single source of origin, and treating and processing that biomass in a consistent manner such that the batches resulting from the process can be deemed to have consistent characteristics. The unique characteristics of the biomass used and the processed biomass characteristics will be consistent across the Production Process.

A Production Batch is then a single, particular batch of feedstock, [math: p], originating from a particular Production Process.

An ‘Injection Batch’, [math: n], is a single injection activity where a quantity of biomass is injected into an approved underground storage site. The Injection Batch may consist of a portion of a Production Batch, a full single Production Batch, or a blend of multiple Production Batches, which is injected for durable storage.

The approach for emissions calculations here is based on Injection- Batches and the specific calculation of net CO₂e removal for each Injection Batch. The following sections outline the process for calculating the net CO₂e removed for each specific Injection Batch of biomass processed and associated biomass injection, defined as a Removal.

The Reporting Period for biomass geological storage projects represents an interval of time over which removals are calculated and reported for verification. When a total net CO₂e removalremovals must be calculated for any specifieda reporting period, for example during submission of Claimed Removals in a GHG statement, it is calculated as the sum of the net CO2e removal of all Injection Batchesremovals during the reporting period:

[math: CO_2e_{Removal,\ RP} = \sum_{n=1}^{k} CO_2e_{Removal,\ n}]

(Equation 1)

Where

• [math: k] = number of Injection Batches [math: n]
• [math: CO_2e_{Removal,\ RP}] = the total net GHGCO₂e removal, as total net greenhouse gas emissions for reporting period [math: RP], in tonnes of CO₂e
• [math: CO_2e_{Removal,\ n}] = the total net GHGCO₂e emissionsremoval for Injection Batch [math: n], in tonnes of CO2e, occurring in reporting period [math: RP], in tonnes of CO₂e, see Section 7.3.2, Equation 2

TotalNote: netReversals removalsoccur mayafter beCredits adjustedhave been issued so are not included in futurethis yearsequation. for a reporting period, [math: RP], due to reversals (see Storage Modules inSee Section 8) that may occur over the duration5.6 of the long-termIsometric storageStandard periodfor further infomartion.

7.3.2 Calculation of CO₂e_{Removal, n}

Net CO₂e removal for a process utilizing biomass injectiongeological intostorage geologic formationproject can be calculated as follows. Note that the calculation is completed for a discrete batch, [math: n], of biomass that is injected (‘Injection Batch’). The final net CO₂e quantification must be conservatively determined, giving high confidence that at least the estimated amount of carbon dioxide was removed.

[math: CO_2e_{Removal,\ n} = CO_2e_{Stored,\ n}\ –\ CO_2e_{Counterfactual,\ n}\ - \\ CO_2e_{LCA\ Emissions,\ n}]

(Equation 2)

Where

• [math: CO_2e_{Stored,\ n}]= the total quantity of GHGsCO₂ removed from the atmosphere, and durably stored as totalbiogenic net greenhouse gas emissionscarbon for batch [math: n], in tonnes of CO₂e, see Section 7.3.3
• [math: CO_2e_{Counterfactual,\ n}]= the total quantity of counterfactual GHG emissions and CO₂e thatremoved wasfrom notthe eligibleatmosphere dueand todurably counterfactual storage duration,stored as totalbiogenic netcarbon greenhousein gasthe emissionsabsense of the project, for batch [math: n], in tonnes of CO₂e, see Section 7.3.4
• [math: CO_2e_{LCA\ Emissions,\ n}]= the total quantity of GHG emissions from operations and embodied emissions, as total net greenhouse gas emissions for a batch [math: n], in tonnes of CO₂e, see Section 7.3.5

7.3.3 Calculation of CO₂e_{Stored, n}

[math: CO_2e_{Stored}] represents the amount of carbon as CO₂e contained(stored inas theorganic biomasscarbon, C) that is injected and stored in the geologic or engineered storage formation. This is the gross amount stored for each batch injection and does not account for spillage nor reversals of storage from the storage formation.

The total amount of carbon dioxide equivalentCO₂ contained in the biomassinjectant thatcan is injected into a geologic formation is considered the gross amount of CO2e stored, or [math: CO_2e_{Stored}],be calculated as: follows.

Where all biomass production batches are blended prior to injection:

[math: CO_2e_{Stored,\ n} = \frac{C_{Biomass,\ n}\cdot m_{Inj,\ n}}{C_{CO_{2}}}]

(Equation 3)

Where biomass production batches are not blended prior to injection:

[math: CO_2e_{Stored,\ n} = \sum_{p=1}^{j} \bigg(\frac{C_{Biomass,\ p}\cdot m_{Inj,\ p}}{C_{CO_{2}}} \bigg)]

(Equation 4)

Where:

• [math: n] = Injection Batch
• [math: p] = Production Batch
• [math: j] = number of Production Batches in Injection Batch ([math: n])
• [math: CO_2e_{Stored,\ n}]= the total grossCO₂ removed for batch [math: n], in tonnes of CO₂e removed for biomass Injection Batch, [math: n]
• [math: C_{Biomass,\ n (p)}] = the concentration as weight percent (%wt) of carbon in the biomass injectant injected for Injection Batch [math: n] OR for each production batch [math: p] included in Injection Batch [math: n]
• [math: m_{Inj,\ n (p)}]= the total mass of injectant emplaced via injection (tonne) for Injection Batch [math: n] OR for each production batch [math: p] included in Injection Batch [math: n]
• [math: C_{CO_{2}}] = the content of carbonC in CO₂, equivalent(as toa 12/44mass = 0.2727percent)

7.3.3.1 Measurements - CO₂e_{Stored, n}

Calculation of [math: CO_2e_{Stored}] requires two primary measurements:

• [math: C_{Biomass}] (- %wt of C in the biomass injectant) and
• [math: m_{Inj}] (- total mass of injectant).

7.3.3.1.1 Biomass Carbon Content Measurement

TheIn valueorder ofto determine [math: C_{Biomass}], the %wt of C in the biomass injectant for either a blended biomass in an Injection Batch [math: n], or for an individual Production BatchBatches [math: p], is determined via the analysis of samples of biomass injectant for total carbonC content. This must be assessed via test method ASTM D5373: Standard Test Methods for Instrumental Determination of Carbon and Hydrogen in Analysis Samples of Coal and Carbon in Analysis Samples of Coal and Coke or similar procedure. 

Care should be taken to ensure biomass products with high vapor pressure are treated to ensure evaporation of volatile components is minimized. Alternative methods or analytical equipment which determine total carbonC content may be utilized if justified and documented to be equivalent to ASTM D5373, for example, EPA 9060A can be used for liquids.

Analysis must be completed by a qualified laboratory, as evidenced by accreditation to ISO 17025 or equivalent standards (Standard physical constants as well as standard values set forth by bodies such as the National Institute of Standards and Technology (NIST) or others.) for laboratory quality management for the specific test method (ASTM D5373, or equivalentD5291).

Laboratories must complete standard quality assurance procedures on a schedule in accordance with their quality management plans and accreditation requirements to include:

• analysis of blanks
• analysis of duplicates
• instrumentation calibrations and analysis of calibration standards

This protocol provides two alternative methods for how often carbonC content must be measured and quantified. The first method (A) involves measuring every batch, the second method (B) involves only sampling some batches, and conservatively estimating the carbonC content of unsampled batches.

Method A: Measure every Batch

Using this method, the carbonC content of every Injection Batch must be ascertained through direct measurement, either by:

1. Sampling the Injection Batch (which may be blended, or non-blended)
2. Sampling all constituent Production Batches which comprise the Injection Batch, and calculating the carbonC content of the Injection Batch through a linear weighted combination of the carbonC contents of these Production Batches, as given in Equation 3.
   • Note that in the case of an unblended Injection Batch, the Injection Batch originates from only a single Production Batch, by definition, and no calculation is required

For the acceptable minimum number of samples to take per sampled Batch, see Minimum number of samples per Batch below. If multiple samples are taken per Batch, the average carbonC content of these samples must be used.

Method B: Sampling a Production Process

For a given Production Process of a feedstock, samples must be taken directly for at least 30 Production Batches, to ensure there is enough data to estimate carbonC content for future Production Batches with appropriate statistical significance. Until this threshold is reached, Method A must be used.

Subsequently, samples must be taken at least every 10 Production Batches.

For the acceptable minimum number of samples to take per Batch, see Minimum number of samples per Batch below.

For batches which are not sampled, carbonC content must be conservatively estimated, as follows:

[math: C_{Biomass} = \mu_{CC} - \sigma_{\overline{CC}}]

(Equation 5)

[math: \sigma_{\overline{CC}} = \frac{\sigma_{CC}}{\sqrt{n_{samples}}}]

(Equation 6)

where:

• [math: \sigma_{\overline{CC}}] is the standard error of the mean of carbonC content, across all eligible samples for this Production Process
• [math: \sigma_{CC}] is the standard deviation of carbonC content, across all eligible samples for this Production Process
• [math: n_{samples}] is the number of eligible samples for this Production Process
• [math: \mu_{CC}] is the mean carbonC content of all eligible samples for this Production Process

Eligible samples are those taken in the previous 6 months before a specific Production Batch was produced. Older samples may not be used.

Additionally, batches must be subject to random sampling, to alleviate the risk of any given batch containing a substance with a substantially different carbonC content.

A random sampling approach must be agreed and documented in the Project Design Document, whereby Isometric will contact the Project Proponent on randomly selected days, at an agreed cadence, which must be no less frequent than once per month, on average. Once contacted, the Project Proponent must sample the carbonC content of the subsequent batches processed.

If the Project Proponent is unable to carry this random sampling out on 3 occasions within a 6 month period, or within a 6 month period more than 3 measurements are below 3 SD from the mean, this will trigger a Project review by Isometric.

If there is a significant change to a Production Process for a feedstock, which is likely to alter the average carbon content of the feedstock, or if significant deviations in carbon content are detected, the feedstock should be considered as a new Production Process. This means that sampling must be restarted, with all prior samples no longer able to be used for estimating carbon content.

Minimum number of samples per Batch

For all measurements taken, samples must be from a well mixed and representative aliquot of the biomass. To account for the possibility of variation within a single Production Batch (for example within a large container of liquid biomass), either of the following approaches must be adopted:

1. A minimum of 3 samples must be taken for each measured Production Batch.
2. Justification and evidence must be provided to demonstrate that the “within batch” variation is likely to be minimal. For example, this could be justified due to the physical details of the Production Process used, or alternatively by providing data examining the “within batch” carbon content variation.

Process for handling carbon content measurement outliers

This process applies only if method B is used to calculate carbon content and should be used whether the batch was sampled or not. For a given Production Process, an Outlier is defined as any individual sample which lies more than 3 standard deviations, [math: \sigmasigma_{CC}], above or below the mean. To minimize the potential overall impact of outlier measurements, all carbonC content measurement outliers must be handled via the applying the technique of "winsorization”, as follows.

For a given measurement, [math: m], the winsorized measurement [math: m_w] is defined as follows:

• For a measurement [math: m] where [math: m > \mu + 3\sigmasigma_{CC}], [math: m_w = \mu + 3\sigmasigma_{CC}]
• For a measurement [math: m] where [math: m < \mu - 3\sigmasigma_{CC}], [math: m_w = \mu - 3\sigmasigma_{CC}]

Where [math: \mu] and [math: \sigma_{CC}] are calculated from all carbon content samples from the same Production Process taken within 6 months of the removal for which we are calculating the carbon content. For estimating the carbon content from sampled batches, only historical samples should be used to calculate [math: \mu] and [math: \sigma_{CC}] and not samples from the batch being calculated. The standard deviation, [math: \sigma_{CC}], should be calculated with the formula for sample standard deviation.

The winsorized measurement, [math: m_w], must be used for the determination of carbonC content.

This winsorization process must only be applied once a minimum number of 30 measurements have been taken, to ensure statistical significance.

The Project Proponent must monitor occurrences of outliers, and investigate if significantly more than the statistically expected number occurs, as it may be indicative of a systematic issue. This may be checked at verification, at the discretion of the verifying VVB.

7.3.3.1.2 Measurement of Mass of Biomass Injected

The mass of injectant, [math: m_{Inj}], is measured via determination of weight of delivered biomass to the injection site using a calibrated scale. The total mass injected may be determined by the difference in biomass delivery truck weight measured upon arrival at the injection facility and at departure, after offloading of biomass, either into storage or directly to injection.

Any truck scale used must have a current certification in accordance with applicable local, state, or federal regulations for legal-for-trade weights and measures. Testing and calibration of scales must utilize certified weights in accordance with local, state, or other regulations, calibration weights must meet NIST Handbook 44 specifications⁷, and scale testing and calibration must be performed by a state certified entity.

The total mass injected may also be determined by other methods, such as use of a calibrated flow meter and density measurement, or use of calibrated on site weigh scales for smaller containers, where such methods are viable and justified. Note that, due to the typical viscosity of biomass, the use of flow meters is not often viable and can result in poor data quality.

7.3.3.2 Required Records & Documentation - CO₂e_{Stored, n}

The project proponent must maintain the following records as evidence of gross CO₂e stored in injected biomass:

• weigh scale tickets for each delivery of biomass (arrival and departure weights) or other equivalent records
• analytical results for each ASTM D5291, or equivalent, analysis for carbonC content of biomass from each batch as required
• Documentation of any spills during injection operations and estimates of quantity released

Records of all C analyses and injection masses (e.g. weigh scale tickets) must be maintained by the injection facility and provided for verification purposes for a period of five years.

7.3.3.3 Other Considerations - CO₂e_{Stored, n}

Although limited and of small quantity, injection processes should be monitored to ensure that any process upsets or equipment failures and resulting spills of biomass are monitored, documented, quantified, and accounted for in the GHG AssessentStatement (A document submitted alongside Claimed Removals and/or Reductions that details the calculations associated with a Removal or Reduction, including the Project's emissions, Removals, Reductions and Leakages, presented together in net metric tonnes of CO₂e per Removal or Reduction.) of the project batch. For each batch, where a process upset results in loss of biomass, that amount must be deducted from the delivered amount of biomass based on delivery weigh tickets. Such amounts must be allocated directly to the specific injection batch of biomass.

7.3.4 Calculation of CO₂e_{Counterfactual, n}

The calculation of [math: CO_2e_{Counterfactual,\ n}], equivalent to [math: CO_2e_{Feedstock}], is determined by the requirements of the Biomass Feedstock Accounting Module.

7.3.5 Calculation of CO₂e_{GHG Emissions, n}

[math: CO_2e_{GHG\ Emissions,\ n}] is the total quantity of GHG emissions from operations and embodied emissions for a batch [math: n]. This can be calculated as:

[math: CO_2e_{GHG\ Emissions,\ n} = CO_2e_{Energy,\ n}\ + CO_2e_{Transportation,\ n}\ + \\ CO_2e_{Embodied,\ n} +  CO_2e_ 
CO_{Monitoring2}e_{Misc.,\ n} +
CO_{2}e_{Leakage, n}]

(Equation 7)

Where

• [math: CO_2e_{GHG\ Emissions,\ n}]= the total quantity of GHG emissions from operations and embodied emissions for a batch [math: n], in tonnes of CO₂e
• [math: CO_2e_{Energy,\ n}]= the total quantity of GHG emissions associated with energy consumption for a batch [math: n], in tonnes of CO₂e, see Section 7.3.5.12
• [math: CO_2e_{Transportation,\ n}]= the total quantity of GHG emissions associated with transportation of products for a batch [math: n], in tonnes of CO₂e, see Section 7.3.5.23
• [math: CO_2e_{Embodied,\ n}]= the total quantity of embodied GHG emissions allocated to a batch [math: n], in tonnes of CO₂e, see Section 7.3.5.34
• [math: CO_2e_{MonitoringMisc.,\ n}] = the total miscellaneous GHG emissions for a given [math: RP], that cannot be categorized by [math: CO_2e_{Energy,\ n}], [math: CO_2e_{Transportation,\ n}], or [math: CO_2e_{Embodied,\ n}], in tonnes CO₂e, see Section 7.3.5.5
• [math: CO_2e_{Leakage,\ n}]= the total quantity of GHG emissions associated with storagethe monitoringproject’s impact on activities that fall outside of the system boundary of a project, allocated to a batch [math: n], in tonnes of CO₂e, see Section 7.3.5.6

Note: Reversals occur after Credits have been issued so are not included in this equation. See Section 5.6 of the Isometric Standard for further infomartion. Risk of reversal information is provided within the relevant Storage Modules in Section 8Module for calculation details.

7.3.5.1 Emissions allocation

Emissions that occur relating to a batch, [math: n], must be included in the reporting of emissions associated with that batch and may not be allocated across multiple batches. Allocation across multiple batches must be agreed with Isometric on a case by case basis.

Embodied emissions which relate to multiple batches may be allocated in line with the allocation rules set out in the Embodied Emissions Accounting Module.

When the Project Proponent is planning to cease operations within a given storage site, the monitoring emissions required for post-closure monitoring must be calculated and allocated to the remaining removals taking place at the storage site. If that is not possible, the Project Proponent should allocate those emissions to other projects and/or storage sites they conduct removal operations at, in agreement with Isometric. If for any reason emissions are not appropriately allocated, the Reversal process will be triggered in accordance with Isometric Standard, to account for any remaining monitoring emissions.

In instances where monitoring activities are shared between entities, for example if multiple companies inject biomass into the same storage infrastructure, the emissions associated with these activities must be allocated proportionally between the entities.

7.3.5.2 Calculation of CO₂e_{Energy, n}

EmissionsGHG emissions associated with energy[math: CO_2e_{Energy, n}] should include all emissions associated with electricity usage, through electricity or fuel combustion. 

Examples of electricity usage may include, but are not limited to:

• processing equipment, motors, drives, instrumentation
• facility operation
• injection
• monitoring operationsequipment operation, including analyzers, instrumentation, on-site laboratories specifically for monitoring activities
• sampling pumps, sampling systems, or other similar monitoring activities
• off site analytical laboratory operation and sample analysis
• electricity for building operation & management for monitoring facility buildings

Examples of fuel consumption may include, but are not limited to:

• emission control (e.g. propane for flare co-firing or pilot)
• handling equipment, such as fork trucks or loaders
• sampling system operation, such as any pumps or heating systems
• monitoring system installation, operation or closure

The Energy Use Accounting Module provides guidance on how energy-related emissions must be calculated so that they can be subtracted in the net CO₂e removal calculation. It sets out the calculation approach to be followed for intensive facilities and non-intensive facilities and acceptable emissions factors.

7.3.5.2 Calculation of CO2eTransportation, n

Emissions related to transportation of products as part of a batch [math: n]’s process.

7.3.5.3 Calculation of CO₂e_{Transportation, n}

GHG emissions associated with [math: CO_2e_{Transportation, n}] should include all emissions associated with transportation of products as part of a batch [math: n]’s process,including the following:

• transportation of biomass feedstock to biomass processing site
• transportation of biomass from processing site to injection site
• transportation of samples for lab analysis

The Transportation Emissions Accounting Module provides guidance on how transportation-related emissions must be calculated so that they can be subtracted in the net CO₂e removal calculation. It sets out the calculation scope and approach to be followed and acceptable emissions factors.

7.3.5.4 Calculation of CO₂e_{Embodied, n}

ExamplesThe Project Proponent must identify all equipment and consumables used in the DAC process, identify appropriate cradle to grave emission factors, and allocate the emissions to removals appropriately in line with the Embodied Emissions Accounting Module.

GHG emissions associated with [math: CO_2e_{Embodied, n}] should include all emissions associated with the procurement and use of materials, consumables and equipment, that must be considered as part of the embodied emission calculation includeincluding but are not limited to:

• non-feedstock process inputs or consumables:
  • catalysts
  • water
  • gasses such as nitrogen used for process or instrumentation purges
  • injection additives (i.e. biocide, salt, etc.)
  • gases, reagents or other materials used for operation of monitoring equipment and on-site analyzers
• equipment:
  • feedstock conveyors, augers, feed bins, and related equipment
  • consumable sampling equipment or supplies that are used in significant quantities
  • temporary storage tanks and facilities
  • all support structures, facilities, and infrastructure, including steel platforms, framing, supports, concrete footings and building structures
  • monitoring wells and all associated materials (steel casing, concrete, etc.)
  • on-line analyzers, measurement equipment, or other such devices
  • buildings and associated equipment utilized for monitoring purposes (e.g. on-site laboratories)

The Embodied Emissions Accounting Module sets out the calculation approach to be followed including allocation of embodied emissions, life cycle stages to be considered and requirements for data sources and emission factors.

7.3.5.5 Calculation of CO₂e_{Misc., n}

GHG emissions associated with [math: CO_2e_{Misc.,\ n}] should include all project emissions that cannot be categorized by [math: CO_2e_{Energy,\ n}], [math: CO_2e_{Transportation,\ n}], or [math: CO_2e_{Embodied,\ n}]. The Project Proponent is responsible for identifying all sources of emissions directly or indirectly related to project activities, including associated with any activities additional to those set out in Section 7.1. The Project Proponent must report such emissions as [math: CO_2e_{Misc.,\ n}].

Examples include, but are not limited to:

• waste processing associated with all aspects of the project's processes
• staff travel associated with the project

7.3.5.6 Calculation of CO₂e_{Leakage, n}

[math: CO_2e_{Leakage,\ n}] includes emissions associated with a project's impact on activities outside the system boundary of the project. This includes instances where the Project causes an increase in GHG emissions by diverting material from other uses or incentivizing increased production activity.

It is the Project Proponent's responsibility to identify potential sources of leakage emissions. For a biomass project, replacement emissions (Any emissions that occur to compensate for biomass that was previously serving another purpose and is now being used for carbon removal or GHG reduction. For example, if agricultural waste was previously left on a field to decompose - fertilizer production to replace those nutrients need to be accounted for.) must be considered as a minimum. The calculations required for replacement emissions associated with market leakage are set out in the Biomass Feedstock Accounting Module.

In line with the Eligibility Criteria set out in the Biomass Feedstock Accounting Module, projects which would lead to ecological leakage associated with land use change are not eligible under this protocol.

8.0 CO₂ Storage

This Protocol may provide multiple options for durable storage of biomass. The Project Proponent can choose from available options when submitting their Project for verification:

A Biomass Storage in Permeable Reservoirs module will be coming soon.

9.0 Acknowledgements

Isometric would like to thank following contributors to this Protocol and relevant modules:

• Tim Hansen (350 Solutions); Biomass Geological Storage Protocol, and Energy Use Accounting, Transportation Emissions Accounting and Embodied Emissions Accounting Modules.
• Kevin Fingerman, Ph.D. (Cal Poly Humboldt); Biomass Feedstock Accounting Module.
• Wilson Ricks (Princeton University); Energy Use Accounting Module.
• Grant Faber (Carbon Based Consulting); Transportation Emissions Accounting Module.

Isometric would like to thank following reviewers of this Protocol and relevant modules:

• Grant Faber (Carbon Based Consulting); Energy Use Accounting Module & Embodied Emissions Accounting Module.
• EcoEngineers; Biomass Geological Storage Protocol.

10.0 Definitions and Acronyms

A document that describes how to quantitatively assess the net amount of CO₂ removed by a process. To Isometric, a Protocol is specific to a Project Proponent's process and comprised of Modules representing the Carbon Fluxes involved in the CDR process. A Protocol measures the full carbon impact of a process against the Baseline of it not occurring.

The term used to represent the CO₂ taken out of the atmosphere as a result of a CDR process.

A body of similar rock type (e.g. color, grain size, mineral composition, texture) and a particular location in the stratigraphic column (vertical rock layers). Formations are large enough to be mappable on Earth's surface or traceable in the subsurface.

A location where carbon is stored. This can be via physical barriers (such as geological formations) or through partitioning based on chemical or biological processes (such as mineralization or photosynthesis).

Describes the addition of carbon dioxide removed from the atmosphere to a reservoir, which serves as its ultimate destination. This is also referred to as “sequestration”.

A range of processes that use biogenic material to remove carbon dioxide (CO₂) from the atmosphere and store that CO₂ underground or in long-lived products (LLNL BiCRS Roadmap, 2020).

An activity or process or group of activities or processes that alter the condition of a Baseline and leads to Removals or Reductions.

Raw material which is used for CO₂ Removal or GHG Reduction.

Life cycle GHG emissions associated with production of materials, transportation, and construction or other processes for goods or buildings.

The increase in GHG emissions outside the geographic or temporal boundary of a project that results from that project's activities.

The process by which all emissions associated with a Project's Removal or Reduction process, including leakages, are accounted for.

​​Considering impacts at each stage of a product's life cycle, from the time natural resources are extracted from the ground and processed through each subsequent stage of manufacturing, transportation, product use, and ultimately, disposal.

A worldwide federation (NGO) of national standards bodies from more than 160 countries, one from each member country.

Those gaseous constituents of the atmosphere, both natural and anthropogenic (human-caused), that absorb and emit radiation at specific wavelengths within the spectrum of terrestrial radiation emitted by the Earth’s surface, by the atmosphere itself, and by clouds. This property causes the greenhouse effect, whereby heat is trapped in Earth’s atmosphere (CDR Primer, 2022).

Lowering future GHG releases from a specific entity.

The amount of CO₂ emissions that would cause the same integrated radiative forcing or temperature change, over a given time horizon, as an emitted amount of GHG or a mixture of GHGs. One common metric of CO₂e is the 100-year Global Warming Potential.

An evaluation of the likelihood that an intervention—for example, a CDR Project—causes a climate benefit above and beyond what would have happened in a no-intervention Baseline scenario.

A process for evaluating and confirming the net Removals and Reductions for a Project, using data and information collected from the Project and assessing conformity with the criteria set forth in the Isometric Standard and the Protocol by which it is governed. Verification must be completed by an Isometric approved third-party (VVB).

Standard physical constants as well as standard values set forth by bodies such as the National Institute of Standards and Technology (NIST) or others.

The amount of time carbon removed from the atmosphere by an intervention – for example, a CDR project – is expected to reside in a given Reservoir, taking into account both physical risks and socioeconomic constructs (such as contracts) to protect the Reservoir in question.

The escape of CO₂ to the atmosphere after it has been stored, and after a Credit has been Issued. A Reversal is classified as avoidable if a Project Proponent has influence or control over it and it likely could have been averted through application of reasonable risk mitigation measures. Any other Reversals will be classified as unavoidable.

An evaluation of the likelihood that an intervention—for example, a CDR Project—causes a climate benefit above and beyond what would have happened in a no-intervention Baseline scenario.

Enhanced hydrocarbon recovery (EHR) is a tertiary hydrocarbon production technique or process where the physicochemical (physical and chemical) properties of the rock and/or the fluids are changed to enhance the recovery of hydrocarbon, typically by altering the chemical, biochemical, density, miscibility, interfacial tension (IFT)/surface tension (ST), viscosity and thermal properties to enable additional hydrocarbon production (SPE, 2023). EHR+ is the specific use of CO₂ injection for EHR where the CO₂ remains stored in the geologic formation permanently (IEA, 2015).

The organization that develops and/or has overall legal ownership or control of a Removal or Reduction Project.

The document that clearly outlines how a Project will generate rigorously quantifiable Additional high-quality Removals or Reductions.

A systematic and independent process for evaluating the reasonableness of the assumptions, limitations and methods that support a Project and assessing whether the Project conforms to the criteria set forth in the Isometric Standard and the Protocol by which the Project is governed. Validation must be completed by an Isometric approved third-party (VVB).

Third-party auditing organizations that are experts in their sector and used to determine if a project conforms to the rules, regulations, and standards set out by a governing body. A VVB must be approved by Isometric prior to conducting validation and verification.

An acceptable difference between reported Removals/emissions or Reductions/emissions and what an auditor determines is the actual Removal/emissions or Reduction/emissions.

A lack of knowledge of the exact amount of CO₂ removed by a particular process, Uncertainty may be quantified using probability distributions, confidence intervals, or variance estimates.

A document submitted alongside Claimed Removals and/or Reductions that details the calculations associated with a Removal or Reduction, including the Project's emissions, Removals, Reductions and Leakages, presented together in net metric tonnes of CO₂e per Removal or Reduction.

Improperly allocating the same Removal or Reduction from a Project Proponent more than once to multiple Buyers.

A set of data describing pre-intervention or control conditions to be used as a reference scenario for comparison.

An assessment of what would have happened in the absence of a particular intervention – i.e., assuming the Baseline scenario.

A set of data describing pre-intervention or control conditions to be used as a reference scenario for comparison.

Resources provided to projects that are generating, or are expected to generate, greenhouse gas (GHG) Emission Reductions or Removals.

Credits are issued to the Credit Account of a Project Proponent with whom Isometric has a Validated Protocol after an Order for Verification and Credit Issuance services from a Buyer and once a Verified Removal or Reduction has taken place.

A publicly visible uniquely identifiable Credit Certificate Issued by a Registry that gives the owner of the Credit the right to account for one net metric tonne of Verified CO₂e Removal or Reduction. In the case of this Standard, the net tonne of CO₂e Removal or Reduction comes from a Project Validated against a Certified Protocol.

The period of time over which a Project Design Document is valid, and over which Removals or Reductions may be Verified, resulting in Issued Credits.

Purposefully erring on the side of caution under conditions of Uncertainty by choosing input parameter values that will result in a lower net CO₂ Removal or GHG Reduction than if using the median input values. This is done to increase the likelihood that a given Removal or Reduction calculation is an underestimation rather than an overestimation.

An estimate of the emissions intensity per unit of an activity.

An analysis of how much different components in a Model contribute to the overall Uncertainty.

A community resource where Project Proponents publish and visualize their early processes, Removal and Reduction data and Protocols – enabling the scientific community to share feedback and advice.

An entity that purchases Removals or Reductions, often with the purpose of Retiring Credits to make a Removal or Reduction claim.

A database that holds information on Verified Removals and Reductions based on Protocols. Registries Issue Credits, and track their ownership and Retirement.

Any process, activity, or mechanism that removes a greenhouse gas, a precursor to a greenhouse gas, or an aerosol from the atmosphere.

Any emissions that occur to compensate for biomass that was previously serving another purpose and is now being used for carbon removal or GHG reduction. For example, if agricultural waste was previously left on a field to decompose - fertilizer production to replace those nutrients need to be accounted for.

Any process, activity, or mechanism that removes a greenhouse gas, a precursor to a greenhouse gas, or an aerosol from the atmosphere.

The amount of carbon exchanged between two or more Reservoirs over a period of time.

Occur when a Sink – created or enhanced by human activity – removes greenhouse gasses from the atmosphere (CDR Primer, 2022).

Emissions that are produced by a specific CDR process and are directly controllable.

Activities that remove carbon dioxide (CO₂) from the atmosphere and store it in products or geological, terrestrial, and oceanic Reservoirs. CDR includes the enhancement of biological or geochemical sinks and direct air capture (DAC) and storage, but excludes natural CO₂ uptake not directly caused by human intervention.

11.0 Appendix 1: Monitoring Plan Requirements

This appendix details how the Project Proponent must monitor, document and report all metrics identified within this Protocol. Following this guidance will ensure the Project Proponent measures and confirms carbon dioxide removed and long-term storage compliance, and will enable quantification of the emissions removal resulting from the Project activity during the Project Crediting Period, prior to each Verification.

This methodology utilizes a comprehensive monitoring and documentation framework that captures the GHG impact in each stage of a Project. Monitoring and detailed accounting practices must be conducted throughout to ensure the continuous integrity of the carbon dioxide removals and crediting.

The Project Proponent must develop and apply a monitoring plan according to ISO 14064-2 principles of transparency and accuracy that allows the quantification and proof of GHG emissions removals.

11.1 Modular requirements

The Modules associated with this Protocol have their own set of required parameters that need to be monitored. Please refer to the following Sections of the Modules to see a complete list of all requirements:

• Biomass Feedstock Accounting Module 1.2
• Biomass Storage in Salt Caverns Module 1.0

11.2 Net CDR Calculation Requirements

These parameters must be monitored for the purpose of Carbon Emissions Calculation and Embodied Carbon Emissions Calculation.

12.0 Relevant Works

ASTM D5291-21 Standard Test Methods for Instrumental Determination of Carbon, Hydrogen, and Nitrogen in Petroleum Products and Lubricants. (2021, November). https://www.astm.org/standards/d5291

ASTM International. (2018). ASTM D7036: Standard Practice for Competence of Air Emission Testing Bodies. https://www.astm.org/d7036-16.html

California Air Resources Board. (2018, August 13). Carbon Capture and Sequestration Protocol under the Low Carbon Fuel Standard. https://ww2.arb.ca.gov/sites/default/files/2020-03/CCS_Protocol_Under_LCFS_8-13-18_ada.pdf

Carbon Direct & EcoEngineers. (2022). Bio-oil Sequestration Prototype Protocol for Measurement, Reporting, & Verification. https://d13en5kcqwfled.cloudfront.net/files/Bio-oil-proto-protocol.pdf

International Energy Agency. (n.d.). Insights Series 2015 - Storing CO2 through Enhanced Oil Recovery – Analysis. IEA. Retrieved June 14, 2023, from https://www.iea.org/reports/storing-co2-through-enhanced-oil-recovery

International Organization for Standardization. (2006). ISO 14040:2006 Environmental management — Life cycle assessment — Principles and framework. https://www.iso.org/standard/37456.html

International Organization for Standardization. (2006). ISO 14044:2006 Environmental management — Life cycle assessment — Requirements and guidelines. https://www.iso.org/standard/38498.html

International Organization for Standardization. (2008). Evaluation of measurement data — Guide to the expression of uncertainty in measurement (ISO JGCM GUM). https://www.iso.org/sites/JCGM/GUM/JCGM100/C045315e-html/C045315e.html?csnumber=50461

International Organization for Standardization. (2011). ISO 14066:2011 Greenhouse gases — Competence requirements for greenhouse gas validation teams and verification teams. https://www.iso.org/standard/43277.html

International Organization for Standardization. (2017). ISO/IEC 17025:2017 General requirements for the competence of testing and calibration laboratories. https://www.iso.org/standard/66912.html

International Organization for Standardization. (2019). ISO 14064-2:2019. Greenhouse Gases - Part 2: Specification With Guidance At The Project Level For Quantification, Monitoring And Reporting Of Greenhouse Gas Emissions Or Removal Enhancements. ISO. https://www.iso.org/standard/66454.html

International Organization for Standardization. (2019). ISO 14064-3:2019. Greenhouse gases — Part 3: Specification with guidance for the verification and validation of greenhouse gas statements. ISO. https://www.iso.org/standard/66455.html

International Organization for Standardization. (2022). ISO 9300:2022 Measurement of gas flow by means of critical flow nozzles. https://www.iso.org/standard/77401.html

Isometric. (n.d.). Isometric — Glossary: Defining the terms that appear regularly in our work. Isometric. https://isometric.com/glossary

Matthews, J.B.R. (Ed.). (2018). IPCC, 2018: Annex I: Glossary [Matthews, J.B.R. (ed.)]. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of... Cambridge University Press. https://doi.org/10.1017/9781009157940.008

Methodology for assessing the quality of carbon credits, Version 3.0. (2022, May). https://carboncreditquality.org/methodology.html

NIST. (2023). Specifications, Tolerances, and Other Technical Requirements for Weighing and Measuring Devices - 2023 Edition. NIST. https://www.nist.gov/pml/owm/publications/nist-handbooks/handbook-44-current-edition

Sandalow, D., Aines, R., Friedman, J., McCormick, C., & Sanchez, D. (2020, October 2). Biomass Carbon Removal and Storage (BiRCS) Roadmap. https://www.osti.gov/servlets/purl/1763937

Schmidt, H., Anca-Couce, A., Hagemann, N., Werner, C., Gerten, D., Lucht, W., & Kammann, C. (20118, August 17). Pyrogenic carbon capture and storage. GCB Bioenergy, 11(4), 573-591. https://onlinelibrary.wiley.com/doi/full/10.1111/gcbb.12553

Society of Petroleum Engineers. (2020, April 13). Enhanced oil recovery (EOR) - PetroWiki. PetroWiki. Retrieved June 14, 2023, from https://petrowiki.spe.org/Enhanced_oil_recovery_(EOR)

U.S. Environmental Protection Agency. (2014). Test Methods for Evaluating Solid Waste: Physical/Chemical Methods Compendium (SW-846). https://www.epa.gov/hw-sw846/sw-846-compendium

U.S. Environmental Protection Agency. (2023, April 18). Understanding Global Warming Potentials | US EPA. Environmental Protection Agency. Retrieved June 14, 2023, from https://www.epa.gov/ghgemissions/understanding-global-warming-potentials