(a) Assessment of the WEC obligation. WEC obligation assessments shall be made pursuant to § 99.23 on the basis of information submitted by the date specified in § 99.5 and following the submittal requirements of § 99.6.

(b) Assessment of the WEC obligation for unverified filings. If a WEC filing is unverified but the EPA is able to correct the error(s) based on reported data, the EPA may recalculate the WEC obligation using available information and provide an invoice or refund to the WEC obligated party within 60 days of determining a WEC filing to be unverified. If the WEC obligated party resubmits a WEC filing within that timeframe, the EPA will either verify the resubmission, or take the resubmission into account when calculating the WEC obligation.

(c) Third-party audits for unverified reports. If the EPA is unable to calculate the WEC obligation with available information, the EPA may require the WEC obligated party to undergo a third-party audit. The EPA may require the WEC obligated party to fund and arrange the third-party audit. The WEC obligated party must make available for review to the third-party auditor all records related to the WEC filing pursuant to § 99.7. The WEC obligated party will have the audit completed and direct the third-party auditor to submit the audit results to the EPA and to the WEC obligated party pursuant to § 99.8(c)(1)(vi). The WEC obligated party will resubmit the WEC filing, if necessary, in accordance with § 99.8(c)(2)(i) and (ii). Nothing in this section regarding third-party audits shall be construed to limit the authority of the Administrator to exercise its authorities under § 114 of the CAA.

(1) Third-party reviews. An independent third-party audit of the information provided shall be based on a review of the relevant documents and shall identify each item required by the WEC filing, describe how the independent third-party evaluated the accuracy of the information provided, state whether the independent third-party agrees with the information provided, and identify any exceptions between the independent third-party's findings and the information provided.

(i) Audits required under this section must be conducted by an independent third-party. The auditor must have professional work experience in the petroleum engineering field or related to oil and gas production, gathering, processing, transmission, or storage and must be a qualified professional engineer.

(ii) To be considered an independent third-party, the auditor must not be an employee of the WEC obligated party or its WEC applicable facilities at which the auditor is conducting the independent review.

(iii) The independent third-party shall submit all records pertaining to the audit required under this section, including information supporting all of the requirements of § 99.8(c)(1) to the WEC obligated party.

(iv) The independent third-party must provide to the WEC obligated party documentation of qualifications of professional work experience in the petroleum engineering field or related to oil and gas production, gathering, processing, transmission, or storage.

(v) The WEC obligated party must make the following information available to the auditor(s) for review which were used to develop the WEC filing including:

(A) All records described under § 99.7(d) of the general recordkeeping provisions for this chapter.

(B) All units, operations, processes, and activities for which GHG emissions were calculated.

(C) The GHG emissions calculations and methods used.

(D) The calculations for the development of site-specific emissions factors.

(E) The quantity of petroleum and natural gas received, produced, and consumed at the facility in the calendar year.

(F) The dates on which any measurements were conducted as well as the results of all emissions measured.

(G) The calibration reports for detection and measurement instruments used.

(H) The inventory of petroleum and natural gas for the current and/or prior calendar year.

(I) The annual part 98 reports.

(vi) The WEC obligated party will direct the independent third-party auditor to submit the audit results to the EPA and the WEC obligated party within 90 days of notification by the EPA of the requirement to conduct a third-party audit.

(2) Reporting and recordkeeping requirements for WEC obligated parties following third party audits. (i) The WEC obligated party shall direct the independent third-party auditor to provide the results of the audit to the EPA and the WEC obligated party. After receiving notification from the EPA that the audited information has been verified by the EPA, the WEC obligated party must resubmit the WEC filing, including the WEC obligation amount and all supporting documentation information that is included in reporting requirements under § 99.7, 99.31, 99.42, and 99.51, as applicable, within 30 days of receipt of the EPA notification.

(ii) The WEC obligated party shall provide to the EPA documentation of qualifications of the third-party auditor.

(iii) The WEC obligated party shall retain all records pertaining to the audit required under this section for a period of 5 years from the date of creation and shall deliver such records to the Administrator upon request.

(d) Resubmittal of filings and reports for the current or prior reporting year. If resubmittal of a previously submitted part 98 report and/or WEC filing, submitted as specified in § 99.7(e), results in a change to the WEC obligation determined for a WEC obligated party for the reporting year the following process shall apply:

(1) If the WEC obligation based upon the resubmitted report or filing for the reporting year is less than the WEC obligation previously remitted by the WEC obligated party, the Administrator shall authorize a refund to the WEC obligated party equal to the difference in WEC obligation.

(2) If the WEC obligation based upon the resubmitted report or filing for the reporting year is greater than the WEC obligation previously remitted by the WEC obligated party, the Administrator may issue an invoice or bill to the WEC obligated party payable in accordance with § 99.9(b). WEC obligations not paid in full by the specified due date, or within 30 days of the date of the invoice or bill if a due date is not provided, shall be subject to fees as described in § 99.10.