Regulations last checked for updates: Jan 18, 2025

Title 40 - Protection of Environment last revised: Dec 30, 2025
§ 98.483 - Calculating CO2 geologic sequestration.

You must calculate CO2 sequestered using the following quantification principles from Clause 8.2 of CSA/ANSI ISO 27916:19 (incorporated by reference, see § 98.7).

(a) You must calculate the mass of CO2 stored in association with CO2-EOR (mstored) in the reporting year by subtracting the mass of CO2 loss from operations and the mass of CO2 loss from the EOR complex from the total mass of CO2 input (as specified in equation 1 to this paragraph (a)).

Equation 1 to paragraph (a) mstored = minputmloss operationsmloss EOR complex Where: mstored = The annual quantity of associated storage in metric tons of CO2 mass. minput = The total mass of CO2 mreceived by the EOR project plus mnative (see Clause 8.3 of CSA/ANSI ISO 27916:19 (incorporated by reference, see § 98.7) and paragraph (c) of this section), metric tons. Native CO2 produced and captured in the CO2-EOR project (mnative) can be quantified and included in minput. mloss operations = The total mass of CO2 loss from project operations (see Clauses 8.4.1 through 8.4.5 of CSA/ANSI ISO 27916:19 (incorporated by reference, see § 98.7) and paragraph (d) of this section), metric tons. mloss EOR complex = The total mass of CO2 loss from the EOR complex (see Clause 8.4.6 of CSA/ANSI ISO 27916:19 (incorporated by reference, see § 98.7)), metric tons.

(b) The manner by which associated storage is quantified must assure completeness and preclude double counting. The annual mass of CO2 that is recycled and reinjected into the EOR complex must not be quantified as associated storage. Loss from the CO2 recycling facilities must be quantified.

(c) You must quantify the total mass of CO2 input (minput) in the reporting year according to paragraphs (g)(1) through (3) of this section.

(1) You must include the total mass of CO2 received at the custody transfer meter by the CO2-EOR project (mreceived).

(2) The CO2 stream received (including CO2 transferred from another CO2-EOR project) must be metered.

(i) The native CO2 recovered and included as mnative must be documented.

(ii) CO2 delivered to multiple CO2-EOR projects must be allocated among those CO2-EOR projects.

(3) The sum of the quantities of allocated CO2 must not exceed the total quantities of CO2 received.

(d) You must calculate the total mass of CO2 from project operations (mloss operations) in the reporting year as specified in equation 2 to this paragraph (d).

Equation 2 to paragraph (d) Where: mloss leakage facilities = Loss of CO2 due to leakage from production, handling, and recycling CO2-EOR facilities (infrastructure including wellheads), metric tons. mloss vent/flare = Loss of CO2 from venting/flaring from production operations, metric tons. mloss entrained = Loss of CO2 due to entrainment within produced gas/oil/water when this CO2 is not separated and reinjected, metric tons. mloss transfer=Loss of CO2 due to any transfer of CO2 outside the CO2-EOR project, metric tons. You must quantify any CO2 that is subsequently produced from the EOR complex and transferred offsite.
source: 74 FR 56374, Oct. 30, 2009, unless otherwise noted.
cite as: 40 CFR 98.483