TETRA TECH INC

Evaluation of disclosure controls and procedures and changes in internal control over financial reporting

At September 29, 2024, we carried out an evaluation of the effectiveness of the design and operation of our disclosure controls and procedures. Based on our management's evaluation (with the participation of our principal executive officer and principal financial officer), our principal executive officer and principal financial officer have concluded that, as of the end of the period covered by this report, ourdisclosure controls and procedures (as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act), were effective.

Management's Report on Internal Control over Financial Reporting

Our management is responsible for establishing and maintaining adequate internal control over financial reporting. As defined in Exchange Act Rule 13a-15(f), internal control over financial reporting is a process designed by, or under the supervision of, our principal executive and principal financial officer and effected by our Board of Directors, management and other personnel to provide reasonable assurance regarding the reliability of financial reporting and the preparation of consolidated financial statements for external purposes in accordance with U.S. GAAP. Internal controls include those policies and procedures that (i) pertain to the maintenance of records that in reasonable detail accurately and fairly reflect the transactions and dispositions of our assets; (ii) provide reasonable assurance that transactions are recorded as necessary to permit preparation of financial statements in accordance with U.S. GAAP and that our receipts and expenditures are being made only in accordance with authorizations of our management and directors; and (iii) provide reasonable assurance regarding prevention or timely detection of unauthorized acquisition, use or disposition of our assets that could have a material effect on our consolidated financial statements. Because of its inherent limitations, internal control over financial reporting may not prevent or detect misstatements. Also, projections of any evaluation of effectiveness to future periods are subject to the risk that controls may become inadequate because of changes in conditions, or that the degree of compliance with the policies or procedures may deteriorate. Accordingly, even effective internal control over financial reporting can only provide reasonable assurance of achieving their control objectives.

Under the supervision and with the participation of our management, including our Chief Executive Officer and Chief Financial Officer, we assessed the effectiveness of our internal control over financial reporting at September 29, 2024, based on the criteria in Internal Control – Integrated Framework (2013) issued by the COSO. Based upon this assessment, management has concluded that our internal control over financial reporting was effective at September 29, 2024.

Pricewaterhouse Coopers LLP, the independent registered public accounting firm that audited the consolidated financial statements included in this Form 10-K, has issued a report on our internal control over financial reporting. This report, dated November 19, 2024, appears on pages 51-52 of this Form 10-K.

Consistent with the guidance issued by the Securities and Exchange Commission Staff, management's assessment of internal control over financial reporting excluded LS Technologies ("LST"), which we acquired on January 31, 2024. LST is a wholly owned subsidiary whose total assets and total revenues represent 1.4% and 1.7%, respectively, of the related consolidated financial statement amounts as of and for the fiscal year ended September 29, 2024.

Changes in Internal Control over Financial Reporting

There were no changes in our internal control over financial reporting that occurred during the three months ended September 29, 2024 that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.