Revenue in the quarter was $470.4 million, up 27.4% from $369.2 million, and revenue, net of subcontractor costs, was $277.2 million, up 13.2% from $244.9 million for the same quarter last year. Income from operations for the quarter was $22.7 million, up 6.3% from $21.4 million for the same quarter last year. Net income for the quarter was $12.9 million, up 36.9% from $9.4 million for the same quarter last year. First quarter 2007 results were favorably affected by a $4.0 million litigation reserve reversal, which was offset by a $4.2 million charge from the early retirement of senior notes. Diluted earnings per share (EPS) for the quarter was $0.22, up 37.5% from $0.16 for the same quarter last year. Backlog at the end of the quarter was a record $1.30 billion, up 25.9% from $1.03 billion at the end of the same quarter last year. Cash used in operations was $18.1 million for each of the first quarters of fiscal 2007 and 2008.

Compared to the first quarter of fiscal 2007, Tetra Tech's federal government business grew 7.1%, driven by the Company's ARD acquisition; state and local business grew 33.6%, driven by municipal combined sewer overflow (CSO) programs; and commercial business grew 11.9%, driven by contributions across all segments.

Reflecting on the first quarter results, Tetra Tech's CEO Dan Batrack remarked, "The first quarter was one of the Company's strongest growth periods in the past three years. We continued to see broad-based demand for our services across all of our end markets. We reached a new record backlog of $1.3 billion and achieved a sequential reduction in our days in sales outstanding this quarter. Looking forward, we expect to achieve annual revenue and EPS growth of more than 15%."

In thousands (except EPS data)                  Three Months Ended
                                            --------------------------
                                            December 30, December 31,
                                                2007          2006
                                            ------------ -------------
Revenue                                        $470,387      $369,153
Revenue, net of subcontractor costs             277,161       244,871
Income from operations                           22,711        21,365
  Interest expense, net                            (660)         (749)
  Loss on retirement of debt                          -        (4,226)
  Income tax expense                             (9,151)       (6,964)
                                            ------------ -------------
Net income                                     $ 12,900      $  9,426
                                            ============ =============

EPS:
   Basic                                       $   0.22      $   0.16
                                            ============ =============
   Diluted                                     $   0.22      $   0.16
                                            ============ =============

Weighted average common shares outstanding:
   Basic                                         58,313        57,712
   Diluted                                       59,163        58,220

Business Outlook

The following statements are based on current expectations. These statements are forward-looking and the actual results could differ materially. These statements do not include the potential impact of transactions that may be completed or developments that become evident after the date of this release. The Business Outlook section should be read in conjunction with the information on forward-looking statements at the end of this release.

Tetra Tech expects diluted EPS for the second quarter of fiscal 2008 to be in the range of $0.19 to $0.21. Revenue, net of subcontractor costs, for the second quarter is expected to range from $260 million to $280 million. For fiscal 2008, Tetra Tech is narrowing its earnings guidance, and now expects diluted EPS to be $0.87 to $0.93. Revenue, net of subcontractor costs, for fiscal 2008 is expected to range from $1.11 billion to $1.21 billion.

Webcast

Investors will have the opportunity to access a live audio-visual webcast and supplemental financial information concerning the first quarter results through a link posted on the Company's web site at www.tetratech.com on January 31, 2008 at 8:00 a.m. (PST).

About Tetra Tech (www.tetratech.com)

Tetra Tech is a leading provider of consulting, engineering, and technical services. With approximately 8,500 associates located in the United States and internationally, the Company supports commercial and government clients in the areas of resource management and infrastructure. Tetra Tech's services include research and development, applied science and technology, engineering design, program management, construction management, construction, and operations and maintenance.

Forward-Looking Statements

This news release contains forward-looking statements that are subject to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. These forward-looking statements include information concerning future events and the future financial performance of Tetra Tech that involve risks and uncertainties. Readers are cautioned that these forward-looking statements are only predictions and may differ materially from actual future events or results. Readers are urged to read the documents filed by Tetra Tech with the SEC, specifically the most recent reports on Form 10-K, 10-Q, and 8-K, each as it may be amended from time to time, which identify risk factors that could cause actual results to differ materially from the forward-looking statements. Among the important factors or risks that could cause actual results or events to differ materially from those in the forward-looking statements in this release are: fluctuations in quarterly operating results; the impact of downturns in the financial markets and reductions in government budgets; volatility of common stock value; concentration of revenues from government agencies and funding disruptions by these agencies; failure to properly manage projects; acquisition strategy risks; management of growth strategy; use of the percentage-of-completion method of accounting; adverse resolution of an IRS examination; loss of key personnel or the inability to attract and retain qualified personnel; implementation of the enterprise resource planning system; international operations risks; credit risks associated with commercial clients; violations of government contractor regulations; competitive bidding for government contracts; the affect of a negative government audit; the inability to accurately estimate contract risks, revenue, and costs; backlog cancellation and adjustments; client base consolidation; failure of partners to perform on joint projects; inability to find qualified subcontractors; changes in existing environmental laws, regulations, or programs; competition; restrictive covenants in debt agreements; risks of professional and other liabilities; adverse resolution of litigation; conflict of interest issues; changes in accounting for equity-related compensation; expenses associated with corporate governance; and disruption of operations due to computer viruses or terrorism. Any projections in this release are based on limited information currently available to Tetra Tech, which is subject to change. Although any such projections and the factors influencing them will likely change, Tetra Tech will not necessarily update the information, since Tetra Tech will only provide guidance at certain points during the year. Readers should not place undue reliance on forward-looking statements since such information speaks only as of the date of this release.

SOURCE: Tetra Tech, Inc.

Tetra Tech, Inc.
Jorge Casado, Investor Relations
Talia Starkey, Media & Public Relations
626-351-4664