TTEK / Tetra Tech, Inc. - Документы SEC, Годовой отчет, Доверенное заявление

Тетра Тех, Инк.
US ˙ NasdaqGS ˙ US88162G1031

Основная статистика
LEI 549300UJ1LP7JGJC5P32
CIK 831641
SEC Filings
All companies that sell securities in the United States must register with the Securities and Exchange Commission (SEC) and file reports on a regular basis. These reports include company annual reports (10K, 10Q), news updates (8K), investor presentations (found in 8Ks), insider trades (form 4), ownership reports (13D, and 13G), and reports related to the specific securities sold, such as registration statements and prospectus. This page shows recent SEC filings related to Tetra Tech, Inc.
SEC Filings (Chronological Order)
На этой странице представлен полный хронологический список документов SEC, за исключением документов о собственности, которые мы предоставляем в других местах.
August 1, 2025 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

August 1, 2025 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 29, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH, I

July 30, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 30, 2025 TETRA TECH, INC. (E

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 30, 2025 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Numbe

July 30, 2025 EX-99.1

Tetra Tech Reports Strong Third Quarter 2025 Results · Revenue $1.37 billion and Net Revenue $1.15 billion · Net Revenue of $1.06 billion, up 11% Y/Y excluding USAID and DOS · Operating Income $165 million, up 28% Y/Y · EPS $0.43, up 34% Y/Y · Operat

Exhibit 99.1 NEWS RELEASE July 30, 2025 Tetra Tech Reports Strong Third Quarter 2025 Results · Revenue $1.37 billion and Net Revenue $1.15 billion · Net Revenue of $1.06 billion, up 11% Y/Y excluding USAID and DOS · Operating Income $165 million, up 28% Y/Y · EPS $0.43, up 34% Y/Y · Operating Cash Flow $350 million, up 148% Y/Y Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provi

May 8, 2025 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

May 8, 2025 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 30, 2025 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH,

May 7, 2025 EX-99.1

Tetra Tech Reports Strong Second Quarter Results and Raises FY25 Guidance

Exhibit 99.1 NEWS RELEASE May 7, 2025 Tetra Tech Reports Strong Second Quarter Results and Raises FY25 Guidance ● Record Second Quarter Revenue $1.322 billion ● Record Second Quarter Net Revenue $1.104 billion ● Record Second Quarter Adjusted Operating Income $130 million ● Increasing Quarterly Dividend +12% Y/Y ● Raising FY25 EPS Guidance Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a l

May 7, 2025 EX-10.1

Fourth Amended and Restated Credit Agreement dated as of May 5, 2025 among Tetra Tech, Inc., Tetra Tech Canada Holding Corporation, Tetra Tech UK Holdings Limited, Tetra Tech Australia Group Holdings Pty Ltd, Bank of America, N.A., as Administrative Agent and the lenders party thereto.*

Exhibit 10.1 Execution Version Published Deal CUSIP Number: 88163BAP8 Published Revolving Credit Facility CUSIP Number: 88163BAQ6 Published 3-Year Term Loan Facility CUSIP Number: 88163BAR4 Published 5-Year Term Loan Facility CUSIP Number: 88163BAS2 FOURTH AMENDED AND RESTATED CREDIT AGREEMENT Dated as of May 5, 2025 among TETRA TECH, INC., TETRA TECH CANADA HOLDING CORPORATION, TETRA TECH UK HOLD

May 7, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 5, 2025 TETRA TECH, INC. (Exa

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 5, 2025 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Number)

February 28, 2025 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 24, 2025 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

January 31, 2025 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

January 31, 2025 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended December 29, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TEC

January 30, 2025 EX-99.1

Tetra Tech Reports Strong First Quarter Results

Exhibit 99.1 NEWS RELEASE January 29, 2025 Tetra Tech Reports Strong First Quarter Results · Record Revenue $1.42 billion, up 16% Y/Y · Record Net Revenue $1.20 billion, up 18% Y/Y · Operating Income $23 million; adjusted operating income $138 million, up 24% Y/Y · Record Backlog $5.44 billion, up 15% Y/Y · Raised high-end and reaffirmed midpoint of FY25 EPS guidance Pasadena, California. Tetra Te

January 30, 2025 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 29, 2025 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

January 17, 2025 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 17, 2025 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

January 16, 2025 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.           )

TABLE OF CONTENTS UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.           ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted

January 16, 2025 DEFA14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Defin

November 21, 2024 SC 13G

TTEK / Tetra Tech, Inc. / PICTET ASSET MANAGEMENT SA - SC 13G Passive Investment

SC 13G 1 d878074dsc13g.htm SC 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No.  )* Tetra Tech Inc (Name of Issuer) COMMON STOCK (Title of Class of Securities) 88162G103 (CUSIP Number) 2024/09/30 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule purs

November 19, 2024 EX-97.1

Incentive Compensation Recoupment Policy +

Tetra Tech, Inc. Incentive Compensation Recoupment Policy 1.Introduction The Compensation Committee (the “Compensation Committee”) of the Board of Directors (the “Board”) of Tetra Tech, Inc., a Delaware corporation (the “Company”), has determined that it is in the best interests of the Company and its stockholders to adopt this Incentive Compensation Recoupment Policy (this “Policy”) providing for

November 19, 2024 EX-95

Mine Safety Disclosures.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

November 19, 2024 EX-21

Subsidiaries of the Company.+

Exhibit 21 Subsidiaries of Tetra Tech, Inc. NAME JURISDICTION OF FORMATION Advanced Management Technology, Inc. Virginia American Environmental Group, Ltd. Ohio Amyx, Inc. Delaware ARD, Inc. Vermont Ardaman & Associates, Inc. Florida BlueWater Federal Solutions, Inc. Delaware Cosentini Associates, Inc. New York Global Tech Inc. Virginia Glumac California Hoare Lea LLP United Kingdom INDUS Corporat

November 19, 2024 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended September 29, 2024 ☐ TRANSITION REPORT PURSU

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended September 29, 2024 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number 0-19655 TETRA TECH, INC. (E

November 19, 2024 EX-4.3

Description of Capital Stock.+

Exhibit 4.3 DESCRIPTION OF CAPITAL STOCK The following description of our common stock is a summary and does not purport to be complete. This summary is qualified in its entirety by reference to the provisions of the Delaware General Corporation Law (“DGCL”) and the complete text of our Restated Certificate of Incorporation (our “Certificate of Incorporation”), and our Bylaws (our “Bylaws”). We en

November 19, 2024 EX-19.2

Tetra Tech, Inc. and Subsidiaries Insider Trading Policy – Pre-Clearance and Blackout Procedures.+

TETRA TECH, INC. AND SUBSIDIARIES Insider Trading Policy – Pre-Clearance and Blackout Procedures OVERVIEW To help prevent inadvertent violations of the Federal securities laws and to avoid even the appearance of trading on inside information, Tetra Tech (the “Company”) has adopted these Pre-Clearance and Blackout Procedures (“Procedures”) in connection with the Company’s Insider Trading Policy. Th

November 19, 2024 EX-19.1

Tech, Inc. and Subsidiaries Insider Trading Policy.+

TETRA TECH, INC. AND SUBSIDIARIES Insider Trading Policy I.THE NEED FOR A POLICY STATEMENT Federal securities laws prohibit the purchase or sale of securities by a person who is aware of material nonpublic information, and the disclosure of material nonpublic information to others who then trade in a company's securities. Insider trading violations are pursued vigorously by the Securities and Exch

November 13, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 13, 2024 TETRA TECH, INC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 13, 2024 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

November 13, 2024 EX-99.1

Tetra Tech Reports Record Fiscal 2024 and Fourth Quarter Results

Exhibit 99.1 NEWS RELEASE November 13, 2024 Tetra Tech Reports Record Fiscal 2024 and Fourth Quarter Results · Record Annual Revenue $5.20 billion, up 15% Y/Y · Record Annual Net Revenue $4.32 billion, up 15% Y/Y · Record Annual Operating Income of $501 million, up 40% Y/Y · Record Annual EPS, up 21% Y/Y · Record Backlog of $5.38 billion, up 12% Y/Y Pasadena, California. Tetra Tech, Inc. (NASDAQ:

September 6, 2024 EX-3.1

Amendment to the Restated Certificate of Incorporation of Tetra Tech, Inc., dated September 6, 2024

Exhibit 3.1 CERTIFICATE OF AMENDMENT TO RESTATED CERTIFICATE OF INCORPORATION OF TETRA TECH, INC. Tetra Tech, Inc. (the “Corporation”), a corporation organized and existing under the laws of the State of Delaware, hereby certifies as follows: FIRST: That the first paragraph of Article IV of the Restated Certificate of Incorporation is hereby amended to read in its entirety as follows: “The total n

September 6, 2024 8-K

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 6, 2024 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

August 2, 2024 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

August 2, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH, I

August 2, 2024 EX-99.1

Tetra Tech Appoints John M. Douglas as New Board Member

Exhibit 99.1 NEWS RELEASE August 2, 2024 Tetra Tech Appoints John M. Douglas as New Board Member Pasadena, California.  Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services in water, environment, and sustainable infrastructure, announced today that the Board of Directors has appointed John M. Douglas as its newest Board Member. Mr. Douglas joins the B

August 2, 2024 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 29, 2024 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Numbe

July 31, 2024 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 31, 2024 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Numbe

July 31, 2024 EX-99.1

Tetra Tech Reports Record Third Quarter Results, Raises Guidance and Announces Five-for-One Stock Split

Exhibit 99.1 NEWS RELEASE July 31, 2024 Tetra Tech Reports Record Third Quarter Results, Raises Guidance and Announces Five-for-One Stock Split · Record Quarterly Revenue $1.34 billion, up 11% Y/Y · Record Q3 Operating Income $129 million, up 32% Y/Y · Record Q3 EPS $1.59, up 42% Y/Y · Record Backlog $5.23 billion, up 19% Y/Y · Increasing FY 2024 Net Revenue and EPS guidance Pasadena, California.

May 24, 2024 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 21, 2024 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Number

May 3, 2024 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

May 3, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH,

May 1, 2024 EX-99.1

Tetra Tech Reports Record Second Quarter Results and Raises Full Fiscal Year Guidance

Exhibit 99.1 NEWS RELEASE May 1, 2024 Tetra Tech Reports Record Second Quarter Results and Raises Full Fiscal Year Guidance · Record Revenue $1.25 billion and Record Net Revenue $1.05 billion · Record Q2 EBITDA $135 million, up 28% Y/Y · Record Q2 EPS of $1.42, up 34% Y/Y · Increasing Fiscal Year 2024 Net Revenue and EPS full year guidance Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a l

May 1, 2024 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 1, 2024 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Number)

April 5, 2024 CORRESP

TETRA TECH, INC. 3475 East Foothill Boulevard Pasadena, California 91107 April 5, 2024

TETRA TECH, INC. 3475 East Foothill Boulevard Pasadena, California 91107 April 5, 2024 VIA EDGAR Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549-4631 Attention: Robert Shapiro Re: Form 10-K for Fiscal Year Ended October 1, 2023 Form 8-K Furnished November 15, 2023 Response dated March 1, 2024 File No. 000-19655 Dear Mr. Shapiro: By lette

March 1, 2024 8-K

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 29, 2024 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

March 1, 2024 CORRESP

TETRA TECH, INC. 3475 East Foothill Boulevard Pasadena, California 91107 March 1, 2024

TETRA TECH, INC. 3475 East Foothill Boulevard Pasadena, California 91107 March 1, 2024 VIA EDGAR Securities and Exchange Commission Division of Corporation Finance 100 F Street, N.E. Washington, D.C. 20549-4631 Attention: Robert Shapiro Re: Form 10-K for Fiscal Year Ended October 1, 2023 Form 8-K Furnished November 15, 2023 File No. 000-19655 Dear Mr. Shapiro: By letter dated January 30, 2024, you

February 14, 2024 SC 13G/A

TTEK / Tetra Tech, Inc. / ALLIANCEBERNSTEIN L.P. - SEC SCHEDULE 13G Passive Investment

SC 13G/A 1 SEC13GFiling.htm SEC SCHEDULE 13G UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 1 )* Tetra Tech Inc (Name of Issuer) Common Stock (Title of Class of Securities) 88162G103 (CUSIP Number) December 31, 2023 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to desi

February 13, 2024 SC 13G/A

TTEK / Tetra Tech, Inc. / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 14)* Name of issuer: Tetra Tech Inc Title of Class of Securities: Common Stock CUSIP Number: 88162G103 Date of Event Which Requires Filing of this Statement: December 29, 2023 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒ Rul

February 2, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TEC

February 2, 2024 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

January 31, 2024 EX-99.1

Tetra Tech Reports Strong First Quarter Results and Raises Full Fiscal Year Guidance

Exhibit 99.1 NEWS RELEASE January 31, 2024 Tetra Tech Reports Strong First Quarter Results and Raises Full Fiscal Year Guidance · Revenue $1.23 billion, up 37% Y/Y · Net revenue $1.02 billion, up 38% Y/Y · EBITDA $131 million, up 32% Y/Y · Backlog of $4.74 billion, up 24% Y/Y · Increasing Fiscal Year 2024 net revenue and EPS full year guidance Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK),

January 31, 2024 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 31, 2024 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

January 18, 2024 DEFA14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ¨ Defin

January 18, 2024 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.           )

TABLE OF CONTENTS UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.           ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted

November 22, 2023 EX-21

Subsidiaries of the Company.+

Exhibit 21 Subsidiaries of Tetra Tech, Inc. NAME JURISDICTION OF FORMATION Advanced Management Technology, Inc. Virginia American Environmental Group, Ltd. Ohio Amyx, Inc. Delaware ARD, Inc. Vermont Ardaman & Associates, Inc. Florida BlueWater Federal Solutions, Inc. Delaware Cosentini Associates, Inc. New York Global Tech Inc. Virginia Glumac California Hoare Lea LLP United Kingdom INDUS Corporat

November 22, 2023 EX-95

Mine Safety Disclosures.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

November 22, 2023 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended October 1, 2023 ☐ TRANSITION REPORT PURSUANT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended October 1, 2023 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number 0-19655 TETRA TECH, INC. (Exac

November 15, 2023 EX-99.1

Tetra Tech Reports Record Fourth Quarter and Fiscal 2023 Results

Exhibit 99.1 NEWS RELEASE November 15, 2023 Tetra Tech Reports Record Fourth Quarter and Fiscal 2023 Results · Revenue $1.26 billion, up 40% Y/Y · Net revenue $1.06 billion, up 44% Y/Y · Quarterly adjusted EBITDA $153 million, up 51% Y/Y · Backlog of $4.79 billion, up $1.05 billion Y/Y · Initiates FY24 revenue and EPS guidance at double-digit growth Pasadena, California. Tetra Tech, Inc. (NASDAQ:

November 15, 2023 8-K/A

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 28, 2023 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File

November 15, 2023 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 15, 2023 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

August 22, 2023 EX-99.3

Description of Capital Stock

Exhibit 99.3 Description of Capital Stock The following description of our common stock is a summary and does not purport to be complete. This summary is qualified in its entirety by reference to the provisions of the Delaware General Corporation Law (“DGCL”) and the complete text of our Restated Certificate of Incorporation (our “Certificate of Incorporation”), and our Bylaws (our “Bylaws”). We e

August 22, 2023 EX-10.3

Amendment No. 2 to Third Amended and Restated Credit Agreement dated as of August 17, 2023 among Tetra Tech, Inc., Tetra Tech Canada Holding Corporation, Tetra Tech UK Holdings Limited, Tetra Tech Coffey Pty Ltd, the subsidiary guarantors and the lenders party thereto and Bank of America, N.A., as administrative agent (incorporated by reference to Exhibit 10.3 to the Company’s Current Report on Form 8-K dated August 22, 2023).

Exhibit 10.3 AMENDMENT NO. 2 TO THIRD AMENDED AND RESTATED CREDIT AGREEMENT THIS AMENDMENT NO. 2 TO THIRD AMENDED AND RESTATED CREDIT AGREEMENT (this “Amendment”), dated as of August 17, 2023, is entered into among TETRA TECH, INC., a Delaware corporation (the “Company”), TETRA TECH CANADA HOLDING CORPORATION, TETRA TECH UK HOLDINGS LIMITED (formerly known as Coffey UK Limited), TETRA TECH COFFEY

August 22, 2023 EX-99.2

Tetra Tech Announces Pricing of $500 Million Offering of Convertible Senior Notes

Exhibit 99.2 Tetra Tech Announces Pricing of $500 Million Offering of Convertible Senior Notes PASADENA, Calif. – Tetra Tech, Inc. (Nasdaq: TTEK), a leading provider of high-end consulting and engineering services, announced today the pricing of $500.0 million aggregate principal amount of 2.25% Convertible Senior Notes due 2028 (the “notes”) in a private placement (the “offering”) only to persons

August 22, 2023 8-K

Entry into a Material Definitive Agreement, Unregistered Sales of Equity Securities, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 17, 2023 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Num

August 22, 2023 EX-10.2

Amendment No. 1 to Third Amended and Restated Credit Agreement dated as of August 4, 2023 among Tetra Tech, Inc., Tetra Tech Canada Holding Corporation, Tetra Tech UK Holdings Limited, Tetra Tech Coffey Pty Ltd, the subsidiary guarantors and the lenders party thereto and Bank of America, N.A., as administrative agent (incorporated by reference to Exhibit 10.2 to the Company’s Current Report on Form 8-K dated August 22, 2023).

Exhibit 10.2 AMENDMENT NO. 1 TO THIRD AMENDED AND RESTATED CREDIT AGREEMENT THIS AMENDMENT NO. 1 TO THIRD AMENDED AND RESTATED CREDIT AGREEMENT (this “Amendment”), dated as of August 4, 2023, is entered into among TETRA TECH, INC., a Delaware corporation (the “Company”), TETRA TECH CANADA HOLDING CORPORATION, TETRA TECH UK HOLDINGS LIMITED (formerly known as Coffey UK Limited), TETRA TECH COFFEY P

August 22, 2023 EX-10.1

Form of Confirmation for Capped Call Transactions (incorporated by reference to Exhibit 10.1 to the Company’s Current Report on Form 8-K dated August 22, 2023).

Exhibit 10.1 [DEALER] August [], 2023 To: Tetra Tech, Inc. 3475 East Foothill Boulevard Pasadena, California 91107 Attention: [Title of contact] Re: [Base][Additional] Call Option Transaction The purpose of this communication (this “Confirmation”) is to set forth the terms and conditions of the call option transaction entered into on the Trade Date specified below (the “Transaction”) between [Deal

August 22, 2023 EX-99.1

Tetra Tech Announces Proposed Private Placement of $500 Million of Convertible Senior Notes

Exhibit 99.1 Tetra Tech Announces Proposed Private Placement of $500 Million of Convertible Senior Notes PASADENA, Calif. – Tetra Tech, Inc. (Nasdaq: TTEK), a leading provider of high-end consulting and engineering services, announced today that it intends to offer, subject to market conditions and other factors, $500.0 million aggregate principal amount of Convertible Senior Notes due 2028 (the “

August 22, 2023 EX-4.1

Indenture, dated as of August 22, 2023, by and between Tetra Tech, Inc. and U.S. Bank Trust Company, National Association, as Trustee (incorporated by reference to Exhibit 4.1 to the Company’s Current Report on Form 8-K dated August 22, 2023).

Exhibit 4.1 Execution Version TETRA TECH, INC. AND U.S. BANK TRUST COMPANY, NATIONAL ASSOCIATION, as Trustee INDENTURE Dated as of August 22, 2023 2.25% Convertible Senior Notes due 2028 TABLE OF CONTENTS Page ARTICLE 1 Definitions Section 1.01. Definitions 1 Section 1.02. References to Interest 15 ARTICLE 2 Issue, Description, Execution, Registration and Exchange of Notes Section 2.01. Designatio

August 15, 2023 10-K/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1) (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended October 2, 2022 ¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number 0-19655 TE

August 10, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended July 2, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH, IN

August 10, 2023 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

August 9, 2023 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 9, 2023 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Numb

August 9, 2023 EX-99.1

Tetra Tech Reports Record Third Quarter Results

Exhibit 99.1 NEWS RELEASE August 9, 2023 Tetra Tech Reports Record Third Quarter Results · Record Revenue $1.21 billion, up 36% Y/Y · Record EBITDA $119 million, up 33% Y/Y · Record Backlog $4.39 billion, up 25% Y/Y · Increasing Net Revenue and EPS guidance for FY23 Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services, today anno

May 11, 2023 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

May 11, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended April 2, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH, I

May 10, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 10, 2023 TETRA TECH, INC. (Ex

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 10, 2023 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Number

May 10, 2023 EX-99.1

Tetra Tech Reports Record Second Quarter Results

Exhibit 99.1 NEWS RELEASE May 10, 2023 Tetra Tech Reports Record Second Quarter Results · Record Revenue $1.16 billion, up 36% Y/Y · Record Net Revenue $970 million, up 39% Y/Y · EPS $0.80; Adjusted EPS $1.17, up 19% Y/Y · Record Backlog of $4.27 billion, up 18% Y/Y · Increasing Net Revenue and EPS guidance for FY23 Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-

May 8, 2023 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 2, 2023 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Number)

April 10, 2023 EX-99.1

R P S GROUP LIMITED (formerly R P S Group Plc) Consolidated Financial Statements As of and for the year ended December 31, 2022 And Independent Auditors’ Report

Exhibit 99.1 R P S GROUP LIMITED (formerly R P S Group Plc) Consolidated Financial Statements As of and for the year ended December 31, 2022 And Independent Auditors’ Report Independent auditor’s report TO THE BOARD OF R P S GROUP Limited Report on the audit of the financial statements Qualified Opinion We have audited the consolidated financial statements of RPS Group Limited and subsidiaries (th

April 10, 2023 EX-99.2

TETRA TECH INC. UNAUDITED PRO FORMA COMBINED FINANCIAL STATEMENTS

Exhibit 99.2 TETRA TECH INC. UNAUDITED PRO FORMA COMBINED FINANCIAL STATEMENTS On January 24, 2023 (the “Closing Date”), Tetra Tech Inc. (the “Company”, “Tetra Tech”, “we” or “us”) completed the acquisition of RPS Group plc (“RPS”) (the “Acquisition”) pursuant to the terms and conditions of the court-sanctioned scheme of arrangement under Part 26 of the Companies Act 2006 (the “Scheme Agreement”).

April 10, 2023 8-K/A

Financial Statements and Exhibits, Completion of Acquisition or Disposition of Assets

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K/A CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 19, 2023 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File

March 3, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 28, 2023 TETRA TECH, INC

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 28, 2023 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

February 14, 2023 SC 13G

TTEK / Tetra Tech, Inc. / ALLIANCEBERNSTEIN L.P. - SEC SCHEDULE 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Tetra Tech Inc (Name of Issuer) Common Stock (Title of Class of Securities) 88162G103 (CUSIP Number) December 31, 2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule

February 9, 2023 SC 13G/A

TTEK / Tetra Tech, Inc. / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SC 13G/A 1 tv02030-tetratechinc.htm SCHEDULE 13G/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 13)* Name of issuer: Tetra Tech Inc. Title of Class of Securities: Common Stock CUSIP Number: 88162G103 Date of Event Which Requires Filing of this Statement: December 30, 2022 Check the appropriate box to designate the

February 3, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended January 1, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH,

February 3, 2023 SC 13G

TTEK / Tetra Tech, Inc. / PICTET ASSET MANAGEMENT SA - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Tetra Tech Inc (Name of Issuer) COMMON STOCK (Title of Class of Securities) 88162G103 (CUSIP Number) 12/31/2022 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is file

February 3, 2023 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

February 1, 2023 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 1, 2023 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

February 1, 2023 EX-99.1

Tetra Tech Reports Record First Quarter Results

Exhibit 99.1 NEWS RELEASE February 1, 2023 Tetra Tech Reports Record First Quarter Results · Record Net Revenue $737 million · Record EPS $2.18; Record Adjusted EPS $1.34, up 13% Y/Y · Record Backlog of $3.81 billion, up 11% Y/Y Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services, today announced results for the first quarter en

January 24, 2023 EX-99.4

Tetra Tech Completes Acquisition of Global Professional Services Firm RPS Group

Exhibit 99.4 NEWS RELEASE January 24, 2023 Tetra Tech Completes Acquisition of Global Professional Services Firm RPS Group Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services, announced today its offer to acquire all of the outstanding shares of RPS Group through a United Kingdom (UK) court-approved scheme of arrangement has bec

January 24, 2023 EX-99.3

RECOMMENDED CASH ACQUISITION RPS Group plc ("RPS") by Tetra Tech UK Holdings Limited ("Tetra Tech") a wholly-owned subsidiary of Tetra Tech, Inc. De-listing and Cancellation of Trading of RPS Shares

Exhibit 99.3 NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION IN WHOLE OR IN PART, DIRECTLY OR INDIRECTLY, IN, INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OR REGULATIONS OF THAT JURISDICTION FOR IMMEDIATE RELEASE 24 January 2023 RECOMMENDED CASH ACQUISITION of RPS Group plc ("RPS") by Tetra Tech UK Holdings Limited ("Tetra Tech") a wholly-owned subsid

January 24, 2023 8-K

Regulation FD Disclosure, Financial Statements and Exhibits, Completion of Acquisition or Disposition of Assets

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 19, 2023 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

January 24, 2023 EX-99.2

RECOMMENDED CASH ACQUISITION RPS Group plc (“RPS”) by Tetra Tech UK Holdings Limited (“Tetra Tech”) a wholly-owned subsidiary of Tetra Tech, Inc. Scheme of Arrangement Becomes Effective

Exhibit 99.2 NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION IN WHOLE OR IN PART, DIRECTLY OR INDIRECTLY, IN, INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OR REGULATIONS OF THAT JURISDICTION FOR IMMEDIATE RELEASE 23 January 2023 RECOMMENDED CASH ACQUISITION of RPS Group plc (“RPS”) by Tetra Tech UK Holdings Limited (“Tetra Tech”) a wholly-owned subsid

January 24, 2023 EX-99.1

RECOMMENDED CASH ACQUISITION RPS Group plc (“RPS”) by Tetra Tech UK Holdings Limited (“Tetra Tech”) a wholly-owned subsidiary of Tetra Tech, Inc. Court Sanction of Scheme of Arrangement

Exhibit 99.1 NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION IN WHOLE OR IN PART, DIRECTLY OR INDIRECTLY, IN, INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OR REGULATIONS OF THAT JURISDICTION FOR IMMEDIATE RELEASE 19 January 2023 RECOMMENDED CASH ACQUISITION of RPS Group plc (“RPS”) by Tetra Tech UK Holdings Limited (“Tetra Tech”) a wholly-owned subsid

January 17, 2023 DEFA14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

DEFA14A 1 tm233327d2defa14a.htm DEFA14A UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (a

January 17, 2023 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.           )

DEF 14A 1 tm233327-1def14a.htm DEF 14A TABLE OF CONTENTS UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.           ) Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Us

December 12, 2022 EX-99.1

RECOMMENDED CASH ACQUISITION RPS Group plc (“RPS”) by Tetra Tech UK Holdings Limited (“Tetra Tech”) a wholly-owned subsidiary of Tetra Tech, Inc. Receipt of Regulatory Clearances

Exhibit 99.1 NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION IN WHOLE OR IN PART, DIRECTLY OR INDIRECTLY, IN, INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OR REGULATIONS OF THAT JURISDICTION FOR IMMEDIATE RELEASE 12 December 2022 RECOMMENDED CASH ACQUISITION of RPS Group plc (?RPS?) by Tetra Tech UK Holdings Limited (?Tetra Tech?) a wholly-owned subsi

December 12, 2022 SC 13G/A

TTEK / Tetra Tech, Inc. / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 12)* Name of issuer: Tetra Tech Inc. Title of Class of Securities: Common Stock CUSIP Number: 88162G103 Date of Event Which Requires Filing of this Statement: November 30, 2022 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒ Ru

December 12, 2022 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): December 12, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

November 25, 2022 EX-21

Subsidiaries of the Company.+

Exhibit 21 Subsidiaries of Tetra Tech, Inc. NAME JURISDICTION OF FORMATION Advanced Management Technology, Inc. Virginia American Environmental Group, Ltd. Ohio ARD, Inc. Vermont Ardaman & Associates, Inc. Florida Axiom Data Science, LLC Alaska BlueWater Federal Solutions, Inc. Delaware Cosentini Associates, Inc. New York Glumac California Hoare Lea LLP United Kingdom INDUS Corporation Virginia Ma

November 25, 2022 EX-95

Mine Safety Disclosures.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

November 25, 2022 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended October 2, 2022 ☐ TRANSITION REPORT PURSUANT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended October 2, 2022 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number 0-19655 TETRA TECH, INC. (Exac

November 15, 2022 EX-99.1

Tetra Tech Appoints Christiana Obiaya as New Board Member

Exhibit 99.1 NEWS RELEASE November 15, 2022 Tetra Tech Appoints Christiana Obiaya as New Board Member Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services in water, environment, sustainable infrastructure, and renewable energy, announced today that the Board of Directors has appointed Christiana Obiaya as its newest Board Member.

November 15, 2022 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 11, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

November 10, 2022 EX-3.1

Bylaws of the Company (amended and restated as of November 7, 2022) (incorporated by reference to Exhibit 3.1 to the Company's Current Report on Form 8-K dated November 10, 2022).

Exhibit 3.1 BYLAWS OF TETRA TECH, INC. (As Amended and Restated on November 7, 2022) TABLE OF CONTENTS Page ARTICLE I OFFICES 1 Section 1.1 Registered Office 1 Section 1.2 Principal Executive Office 1 Section 1.3 Other Offices 1 ARTICLE II STOCKHOLDERS? MEETINGS 1 Section 2.1 Place of Meetings 1 Section 2.2 Annual Meetings 2 Section 2.3 Special Meetings 7 Section 2.4 Notice of Meetings 8 Section 2

November 10, 2022 8-K

Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 7, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

November 9, 2022 EX-99.1

Tetra Tech Reports Record Fourth Quarter and Fiscal 2022 Results

Exhibit 99.1 NEWS RELEASE November 9, 2022 Tetra Tech Reports Record Fourth Quarter and Fiscal 2022 Results ? Record quarterly revenue $903 million; record annual revenue $3.50 billion ? Record quarterly net revenue $736 million; record annual revenue $2.84 billion ? Record quarterly operating income $95 million; adjusted $94 million, up 29% Y/Y ? Record backlog of $3.74 billion, up $232 million s

November 9, 2022 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 9, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

November 3, 2022 EX-99.1

RECOMMENDED CASH ACQUISITION RPS Group plc ("RPS") by Tetra Tech UK Holdings Limited ("Tetra Tech") a wholly-owned subsidiary of Tetra Tech, Inc. Results of Court Meeting and General Meeting

Exhibit 99.1 NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION IN WHOLE OR IN PART, DIRECTLY OR INDIRECTLY, IN, INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OR REGULATIONS OF THAT JURISDICTION FOR IMMEDIATE RELEASE 3 November 2022 RECOMMENDED CASH ACQUISITION of RPS Group plc ("RPS") by Tetra Tech UK Holdings Limited ("Tetra Tech") a wholly-owned subsid

November 3, 2022 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 3, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

October 28, 2022 8-K

Entry into a Material Definitive Agreement, Termination of a Material Definitive Agreement, Material Modification to Rights of Security Holders, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 26, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

October 28, 2022 EX-10.1

Third Amended and Restated Credit Agreement dated as of October 26, 2022 among Tetra Tech, Inc., Tetra Tech Canada Holding Corporation, Tetra Tech UK Holdings Limited, Tetra Tech Coffey Pty., Ltd., the subsidiary guarantors and the lenders party thereto and Bank of America, N.A., as Administrative Agent (incorporated by reference to Exhibit 10.1 to the Company's Current Report on Form 8-K dated October 28, 2022).

Exhibit 10.1 [***] CERTAIN INFORMATION IN THIS DOCUMENT HAS BEEN EXCLUDED PURSUANT TO REGULATION S-K, ITEM 601(B)(10). SUCH EXCLUDED INFORMATION IS BOTH NOT MATERIAL AND IS THE TYPE THAT THE REGISTRANT TREATS AS PRIVATE OR CONFIDENTIAL. Published Deal CUSIP Number: 88163BAK9 Published Revolving Credit Facility CUSIP Number: 88163BAL7 Published Existing Term Loan Facility CUSIP Number: 88163BAM5 Pu

October 12, 2022 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 11, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

October 12, 2022 EX-99.1

RECOMMENDED CASH ACQUISITION RPS GROUP PLC (“RPS”) TETRA TECH UK HOLDINGS LIMITED (“TETRA TECH”)

Exhibit 99.1 THIS DOCUMENT IS IMPORTANT AND REQUIRES YOUR IMMEDIATE ATTENTION. PART 2 (EXPLANATORY STATEMENT) OF THIS DOCUMENT COMPRISES AN EXPLANATORY STATEMENT UNDER SECTION 897 OF THE COMPANIES ACT. The Scheme, if implemented, will result in the cancellation of the listing of the RPS Shares on the Official List and of trading of the RPS Shares on the London Stock Exchange?s Main Market for list

October 11, 2022 8-K

Entry into a Material Definitive Agreement, Material Modification to Rights of Security Holders, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 7, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Num

October 11, 2022 EX-10.1

Amendment No. 3 to Second Amended and Restated Credit Agreement dated as of October 7, 2022 among Tetra Tech, Inc., Tetra Tech Canada Holding Corporation, Tetra Tech UK Holdings Limited, Tetra Tech Coffey Pty., Ltd., the subsidiary guarantors and the lenders party thereto and Bank of America, N.A., as Administrative Agent.*

Exhibit 10.1 Execution Version AMENDMENT NO. 3 TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT THIS AMENDMENT NO. 3 TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT (this ?Amendment?), dated as of October 7, 2022 (the ?Amendment No. 3 Effective Date?), is entered into among TETRA TECH, INC., a Delaware corporation (the ?Company?), TETRA TECH CANADA HOLDING CORPORATION, TETRA TECH UK HOLDINGS LIMITE

September 26, 2022 8-K

Entry into a Material Definitive Agreement, Financial Statements and Exhibits, Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 23, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File

September 26, 2022 EX-99.1

RECOMMENDED CASH ACQUISITION RPS Group plc by Tetra Tech UK Holdings Limited a wholly-owned subsidiary of Tetra Tech, Inc. to be effected by means of a scheme of arrangement under Part 26 of the Companies Act 2006

Exhibit 99.1 NOT FOR RELEASE, PUBLICATION OR DISTRIBUTION IN WHOLE OR IN PART, IN, INTO OR FROM ANY JURISDICTION WHERE TO DO SO WOULD CONSTITUTE A VIOLATION OF THE RELEVANT LAWS OF SUCH JURISDICTION THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION FOR IMMEDIATE RELEASE 23 September 2022 RECOMMENDED CASH ACQUISITION of RPS Group plc by Tetra Tech UK Holdings Limited a wholly-owned subsidiary of Tetra

September 26, 2022 EX-10.1

Bridge Credit Agreement dated as of September 23, 2022 among Tetra Tech, Inc., the lenders party thereto and BofA Securities, Inc., as sole leader arranger and sole bookrunner (incorporated by reference to Exhibit 10.1 to the Company's Current Report on Form 8-K dated September 26, 2022)

Exhibit 10.1 Execution Version BRIDGE CREDIT AGREEMENT Dated as of September 23, 2022 among TETRA TECH, INC., as Borrower, THE LENDERS PARTY HERETO, BANK OF AMERICA, N.A., as Administrative Agent, and BofA SECURITIES, INC., As Sole Lead Arranger and Sole Bookrunner, TABLE OF CONTENTS Section Page ARTICLE I DEFINITIONS AND ACCOUNTING TERMS 1.01 Defined Terms 1 1.02 Other Interpretive Provisions 34

September 26, 2022 EX-99.3

Tetra Tech to Acquire RPS Group to Expand its Global Operations

Exhibit 99.3 NEWS RELEASE September 23, 2022 Tetra Tech to Acquire RPS Group to Expand its Global Operations ? Advances Tetra Tech?s Global High-End Consultancy in Water, Environment, and Sustainable Infrastructure ? Expands Global Leadership in Energy Transformation, Environmental Management, and Data Analytics ? Strengthens United Kingdom and Australia Operations and Establishes European Union P

September 26, 2022 EX-99.2

Schedule 1 – RPS share plans and employee matters

Exhibit 99.2 Cooperation Agreement Relating to the proposed acquisition of RPS Group plc RPS Group plc Tetra Tech, Inc. Dated 2022 DLA Piper UK LLP is part of DLA Piper, a global law firm, operating through various separate and distinct legal entities. A list of offices and regulatory information can be found at dlapiper.com Contents Parties 1 Background 1 Agreed terms 1 1 Interpretation 1 2 Publi

August 5, 2022 EX-95

Mine Safety Disclosure.

EX-95 6 ttekex95fy22q3.htm EX-95 Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.S. mines that is subject to the Federal Mine Safety and Health Act of 1977 (“MSHA”), the information required by Section 1503(a) of the Dodd-Frank Wall Street Reform and Consumer Protection Act and Item 104 of Regulation S-K. Section references are to sections of MSHA. 3 M

August 5, 2022 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended July 3, 2022 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH, IN

August 3, 2022 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 3, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Numb

August 3, 2022 EX-99.1

Tetra Tech Reports Record Third Quarter Results

Exhibit 99.1 NEWS RELEASE August 3, 2022 Tetra Tech Reports Record Third Quarter Results ? Revenue $890 million, up 11% Y/Y ? Net revenue $720 million, up 13% Y/Y ? Operating income $84 million, up 20% Y/Y ? EPS $1.09, up 15% Y/Y Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services, today announced results for the third quarter e

August 2, 2022 EX-99.1

Tetra Tech Announces Executive Appointments

Exhibit 99.1 NEWS RELEASE August 2, 2022 Tetra Tech Announces Executive Appointments Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services, in alignment with its long-term strategic plan, is announcing today the promotion of Jill M. Hudkins to Tetra Tech President, expanding her role to lead Tetra Tech’s strategic planning and ope

August 2, 2022 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): August 2, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Numb

May 6, 2022 EX-95

Mine Safety Disclosure.

EX-95 6 ttekex95q22022.htm EX-95 Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.S. mines that is subject to the Federal Mine Safety and Health Act of 1977 (“MSHA”), the information required by Section 1503(a) of the Dodd-Frank Wall Street Reform and Consumer Protection Act and Item 104 of Regulation S-K. Section references are to sections of MSHA. 3 M

May 6, 2022 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended April 3, 2022 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH, I

May 4, 2022 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 4, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Number)

May 4, 2022 EX-99.1

Tetra Tech Reports Strong Second Quarter Results

Exhibit 99.1 NEWS RELEASE May 4, 2022 Tetra Tech Reports Strong Second Quarter Results ? Revenue $853 million, up 13% Y/Y ? Net revenue $700 million, up 17% Y/Y ? EPS $0.98, up 18% Y/Y ? Backlog of $3.61 billion, up 15% Y/Y Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services, today announced results for the second quarter ended

March 4, 2022 8-K

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 1, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Numbe

February 22, 2022 8-K

Entry into a Material Definitive Agreement, Material Modification to Rights of Security Holders, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 18, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

February 22, 2022 EX-99.1

Tetra Tech Appoints Prashant Gandhi as New Board Member

Exhibit 99.1 NEWS RELEASE February 22, 2022 Tetra Tech Appoints Prashant Gandhi as New Board Member Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services in water, environment, and sustainable infrastructure, today announced that the Board of Directors has appointed Prashant Gandhi as its newest Board Member. Mr. Gandhi joins the

February 22, 2022 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 22, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

February 22, 2022 EX-99.1

Tetra Tech Announces $1 Billion Credit Facility Linked to Improving the Lives of One Billion People Worldwide

Exhibit 99.1 NEWS RELEASE February 22, 2022 Tetra Tech Announces $1 Billion Credit Facility Linked to Improving the Lives of One Billion People Worldwide Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services in water, environment, and sustainable infrastructure, today announced the establishment of a $1 billion sustainability-link

February 22, 2022 EX-10.1

Amendment No. 2 to Second Amended and Restated Credit Agreement dated as of February 18, 2022 among Tetra Tech, Inc., Tetra Tech Canada Holding Corporation, Tetra Tech UK Holdings Limited, Tetra Tech Coffey Pty., Ltd., the subsidiary guarantors and the lenders party thereto and Bank of America, N.A., as Administrative Agent.

Exhibit 10.1 EXECUTION VERSION AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT THIS AMENDMENT NO. 2 TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT (this ?Amendment?), dated as of February 18, 2022 (the ?Amendment No. 2 Effective Date?), is entered into among TETRA TECH, INC., a Delaware corporation (the ?Company?), TETRA TECH CANADA HOLDING CORPORATION, TETRA TECH UK HOLDINGS LIMI

February 10, 2022 SC 13G/A

TTEK / Tetra Tech, Inc. / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 11)* Name of issuer: Tetra Tech Inc. Title of Class of Securities: Common Stock CUSIP Number: 88162G103 Date of Event Which Requires Filing of this Statement: December 31, 2021 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ??Ru

February 10, 2022 SC 13G

TTEK / Tetra Tech, Inc. / PICTET ASSET MANAGEMENT SA - SC 13G Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. )* Tetra Tech Inc (Name of Issuer) COMMON STOCK (Title of Class of Securities) 88162Gl03 (CUSIP Number) 12/31 /2021 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule is fil

February 4, 2022 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended January 2, 2022 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH,

February 4, 2022 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

February 2, 2022 EX-99.1

Tetra Tech Reports Strong First Quarter Results

Exhibit 99.1 NEWS RELEASE February 2, 2022 Tetra Tech Reports Strong First Quarter Results ? Revenue $859 million, up 12% Y/Y ? Net revenue $679 million, up 12% Y/Y ? EPS $1.25, up 30% Y/Y; Adjusted EPS $1.19, up 24% Y/Y ? Cash flow from operations $82 million, up 148% Y/Y Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services, tod

February 2, 2022 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 2, 2022 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

January 18, 2022 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.           )

TABLE OF CONTENTS UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No.???????? ??) Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? ? Confidential, for Use of the Commission Only (as permitte

January 18, 2022 DEFA14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ? Defin

November 24, 2021 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended October 3, 2021 ☐ TRANSITION REPORT PURSUANT

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended October 3, 2021 ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number 0-19655 TETRA TECH, INC. (Exac

November 24, 2021 EX-95

Mine Safety Disclosures.

EX-95 8 ttek-ex95q410x3x2021.htm EX-95 Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.S. mines that is subject to the Federal Mine Safety and Health Act of 1977 (“MSHA”), the information required by Section 1503(a) of the Dodd-Frank Wall Street Reform and Consumer Protection Act and Item 104 of Regulation S-K. Section references are to sections of MSH

November 24, 2021 EX-21

Subsidiaries of the Company.+

Exhibit 21 Subsidiaries of Tetra Tech, Inc. NAME JURISDICTION OF FORMATION Advanced Management Technology, Inc. Virginia American Environmental Group, Ltd. Ohio America's Schoolhouse Consulting Services, Inc. New York ARD, Inc. Vermont Ardaman & Associates, Inc. Florida BIOCNG, LLC New York BlueWater Federal Solutions, Inc. Delaware Cornerstone Environmental Group, LLC New York Cosentini Associate

November 17, 2021 EX-99.1

Tetra Tech Reports Record Fourth Quarter and Fiscal 2021 Results

Exhibit 99.1 NEWS RELEASE November 17, 2021 Tetra Tech Reports Record Fourth Quarter and Fiscal 2021 Results ? Record quarterly results o Fourth quarter revenue $892 million, up 18% Y/Y o Fourth quarter net revenue $709 million, up 20% Y/Y o Fourth quarter EPS $1.52, up 85% Y/Y and Adjusted EPS $1.05, up 15% Y/Y ? Record backlog of $3.48 billion Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK

November 17, 2021 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 17, 2021 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

October 7, 2021 EX-99.1

Tetra Tech Announces Additional $400 Million Share Repurchase Program

Exhibit 99.1 NEWS RELEASE October 7, 2021 Tetra Tech Announces Additional $400 Million Share Repurchase Program Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services, announced today that its Board of Directors has authorized an additional $400 million share repurchase program, which is twice the size of the previous authorization

October 7, 2021 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): October 7, 2021 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Num

July 30, 2021 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

July 30, 2021 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 27, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH, I

July 28, 2021 EX-99.1

Tetra Tech Reports Record Third Quarter 2021 Results

Exhibit 99.1 NEWS RELEASE July 28, 2021 Tetra Tech Reports Record Third Quarter 2021 Results ? Revenue of $802 million, up 13% Y/Y ? Record Net Revenue of $638 million, up 14% Y/Y ? EPS $0.95, up 14% Y/Y; up 22% Y/Y on an Adjusted Basis ? Record Backlog of $3.25 billion, book-to-bill 1.12x Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineer

July 28, 2021 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 28, 2021 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Numbe

April 30, 2021 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

April 30, 2021 10-Q

Quarterly Report - 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 28, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH,

April 28, 2021 EX-99.1

Tetra Tech Reports Strong Second Quarter 2021 Results · Revenue $755 million and Net Revenue $600 million · Operating Margin up 114 basis points Y/Y · EPS $0.83, up 26% Y/Y · Cash from Operations increased to $124 million, up 23% Y/Y · Increased quar

EX-99.1 2 tm2114394d1ex99-1.htm EXHIBIT 99.1 EXHIBIT 99.1 NEWS RELEASE April 28, 2021 Tetra Tech Reports Strong Second Quarter 2021 Results · Revenue $755 million and Net Revenue $600 million · Operating Margin up 114 basis points Y/Y · EPS $0.83, up 26% Y/Y · Cash from Operations increased to $124 million, up 23% Y/Y · Increased quarterly dividend by 18% to $0.20 Pasadena, California. Tetra Tech,

April 28, 2021 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 28, 2021 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Numb

February 25, 2021 8-K

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 24, 2021 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

February 12, 2021 SC 13G/A

SCHEDULE 13G

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 3 )* TETRA Technologies Inc (Name of Issuer) Common Stock (Title of Class of Securities) 88162F105 (CUSIP Number) December 31, 2020 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this

February 10, 2021 SC 13G/A

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 10)*

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 10)* Name of issuer: Tetra Tech Inc. Title of Class of Securities: Common Stock CUSIP Number: 88162G103 Date of Event Which Requires Filing of this Statement: December 31, 2020 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒ Ru

January 29, 2021 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

January 29, 2021 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended December 27, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TEC

January 27, 2021 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 27, 2021 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

January 27, 2021 EX-99.1

Tetra Tech Reports Strong First Quarter 2021 Results

Exhibit 99.1 NEWS RELEASE January 27, 2021 Tetra Tech Reports Strong First Quarter 2021 Results ● Revenue $765 million and net revenue $605 million ● Operating Margin up 70 basis points Y/Y ● EPS $0.96, up 13% Y/Y ● Cash from Operations increased by $51 million Y/Y ● Days Sales Outstanding improved to 67 days Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end con

January 14, 2021 DEF 14A

- DEF 14A

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ý Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14

January 14, 2021 DEFA14A

- DEFA14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) o Defin

November 23, 2020 EX-95

Mine Safety Disclosures.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

November 23, 2020 10-K

Annual Report - 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended September 27, 2020 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number 0-19655 TETRA TECH, INC. (E

November 23, 2020 EX-21

Subsidiaries of the Company.+

Exhibit 21 Subsidiaries of Tetra Tech, Inc. NAME JURISDICTION OF FORMATION Advanced Management Technology, Inc. Virginia American Environmental Group, Ltd. Ohio America's Schoolhouse Consulting Services, Inc. New York ARD, Inc. Vermont Ardaman & Associates, Inc. Florida BIOCNG, LLC New York BlueWater Federal Solutions, Inc. Delaware Cornerstone Environmental Group, LLC New York Cosentini Associate

November 12, 2020 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 11, 2020 TETRA TECH,INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

November 12, 2020 EX-99.1

Tetra Tech Reports Strong Fourth Quarter and Fiscal 2020 Results

EX-99.1 2 tm2035641d1ex99-1.htm EXHIBIT 99.1 Exhibit 99.1 NEWS RELEASE November 11, 2020 Tetra Tech Reports Strong Fourth Quarter and Fiscal 2020 Results · Fourth quarter revenue $753 million and net revenue $590 million · Fourth quarter EPS $0.82; Adjusted EPS $0.91 · Record fiscal 2020 EPS $3.16, up 11% Y/Y · Record fiscal year cash flow of $262 million, up 26% Y/Y · Record backlog of $3.24 bill

July 31, 2020 10-Q

Quarterly Report - 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 28, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH, I

July 31, 2020 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

July 29, 2020 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 29, 2020 TETRA TECH,INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Number

July 29, 2020 EX-99.1

Tetra Tech Reports Third Quarter 2020 Results

EX-99.1 2 tm2025788d1ex99-1.htm EXHIBIT 99.1 Exhibit 99.1 NEWS RELEASE July 29, 2020 Tetra Tech Reports Third Quarter 2020 Results · Revenue of $710 million and Net Revenue of $560 million · EPS $0.83; Adjusted EPS $0.78 · Cash Flow from Operations increased to $111 million · Backlog grew to $3.07 billion Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consult

June 9, 2020 EX-99.1

Tetra Tech Provides Third Quarter and Fiscal Year 2020 Guidance

Exhibit 99.1 NEWS RELEASE June 9, 2020 Tetra Tech Provides Third Quarter and Fiscal Year 2020 Guidance Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK), a leading provider of high-end consulting and engineering services, today announced guidance for the third quarter and fiscal year 2020, which reflects improved visibility as stay-at-home restrictions in response to the COVID-19 pandemic are

June 9, 2020 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): June 9, 2020 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Number

May 1, 2020 EX-10

Amended and Restated Deferred Compensation Plan (incorporated by reference to Exhibit 10 to the Company's Quarterly Report on Form 10-Q for the fiscal quarter ended March 29, 2020).*

EX-10 2 ttekex10q22020.htm EX-10 Exhibit 10 Tetra Tech, Inc. Deferred Compensation Plan (As Amended and Restated Effective February 26, 2020) Table of Contents Page Article 1 Definitions 1 Article 2 Selection, Enrollment, Eligibility 9 2.1 Selection by Committee 9 2.2 Enrollment and Eligibility Requirements; Commencement of Participation 9 Article 3 Deferral Commitments/Company Contribution Amount

May 1, 2020 10-Q

Quarterly Report - 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 29, 2020 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH,

May 1, 2020 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

April 29, 2020 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): April 29, 2020 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Numb

April 29, 2020 EX-99.1

Tetra Tech Reports Second Quarter 2020 Results

EX-99.1 2 tm2017891d1ex99-1.htm EXHIBIT 99.1 Exhibit 99.1 NEWS RELEASE April 29, 2019 Tetra Tech Reports Second Quarter 2020 Results · Revenue of $734 million and Net Revenue of $584 million · EPS $0.66; Adjusted EPS $0.73 · Increased quarterly dividend by 13% to $0.17 Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK) today announced results for the second quarter ended March 29, 2020 and prov

February 27, 2020 8-K

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 26, 2020 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

February 12, 2020 SC 13G/A

TTEK / Tetra Tech, Inc. / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 9)* Name of issuer: Tetra Tech Inc Title of Class of Securities: Common Stock CUSIP Number: 88162G103 Date of Event Which Requires Filing of this Statement: December 31, 2019 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒ Rule

January 31, 2020 10-Q

Quarterly Report - 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended December 29, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TEC

January 31, 2020 EX-95

Mine Safety Disclosure.

EX-95 6 ttekex95q12020.htm EXHIBIT 95 Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.S. mines that is subject to the Federal Mine Safety and Health Act of 1977 (“MSHA”), the information required by Section 1503(a) of the Dodd-Frank Wall Street Reform and Consumer Protection Act and Item 104 of Regulation S-K. Section references are to sections of MSHA

January 29, 2020 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 29, 2020 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

January 29, 2020 EX-99.1

Tetra Tech Reports Record First Quarter 2020 Results

EX-99.1 2 tm205849d1ex99-1.htm EXHIBIT 99.1 Exhibit 99.1 NEWS RELEASE January 29, 2020 Tetra Tech Reports Record First Quarter 2020 Results · Revenue $798 million, up 11% Y/Y · Net revenue $614 million, up 11% Y/Y · Record Backlog of $3.17 billion, up 13% Y/Y · EPS $0.85, up 13% Y/Y; Adjusted EPS $0.84, up 20% Y/Y Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK) today announced results for th

January 15, 2020 DEFA14A

TTEK / Tetra Tech, Inc. DEFA14A - - DEFA14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) o Defin

January 15, 2020 DEF 14A

TTEK / Tetra Tech, Inc. DEF 14A - - DEF 14A

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ý Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14

November 29, 2019 EX-21

Subsidiaries of the Company.+

Exhibit 21 Subsidiaries of Tetra Tech, Inc. NAME JURISDICTION OF FORMATION Advanced Management Technology, Inc. Virginia American Environmental Group, Ltd. Ohio America's Schoolhouse Consulting Services, Inc. New York ARD, Inc. Vermont Ardaman & Associates, Inc. Florida BIOCNG, LLC New York Cornerstone Environmental Group, LLC New York Cosentini Associates, Inc. New York Delaney Crushed Stone Prod

November 29, 2019 10-K

Annual Report - 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended September 29, 2019 ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number 0-19655 TETRA TECH, INC. (E

November 29, 2019 EX-95

Mine Safety Disclosures.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

November 13, 2019 EX-99.1

Tetra Tech Reports Record Fourth Quarter and Fiscal 2019 Results

Exhibit 99.1 NEWS RELEASE November 13, 2019 Tetra Tech Reports Record Fourth Quarter and Fiscal 2019 Results · Fourth quarter revenue $842 million, up 14% Y/Y · Fourth quarter adjusted net revenue $640 million, up 14% Y/Y · Backlog of $3.1 billion, up 16% Y/Y · Q4-19 EPS $0.21; Adjusted Q4-19 EPS $0.88, up 17% Y/Y Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK) today announced results for th

November 13, 2019 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 13, 2019 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

October 1, 2019 EX-99.1

Tetra Tech Announces Executive Appointments

Exhibit 99.1 NEWS RELEASE September 30, 2019 Tetra Tech Announces Executive Appointments Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK) announced today the promotion of Dr. Leslie Shoemaker to President. In this role she will lead our strategic planning and operating segments. Dr. Shoemaker joined Tetra Tech 28 years ago, and has held increasingly responsible positions including project man

October 1, 2019 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): September 30, 2019 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File

August 2, 2019 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

August 2, 2019 10-Q

Quarterly Report - 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH, I

July 31, 2019 EX-99.1

Tetra Tech Reports Record Third Quarter 2019 Results

EX-99.1 2 a19-163111ex99d1.htm EX-99.1 Exhibit 99.1 NEWS RELEASE July 31, 2019 Tetra Tech Reports Record Third Quarter 2019 Results · Record revenue of $826 million, up 8% Y/Y · Record net revenue of $623 million, up 9% Y/Y · Record backlog of $2.83 billion, up 16% Y/Y · EPS $0.88; adjusted EPS $0.89, up 25% Y/Y Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK) today announced results for the

July 31, 2019 8-K

Results of Operations and Financial Condition, Other Events, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 31, 2019 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Numbe

May 3, 2019 10-Q

Quarterly Report - 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ý QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2019 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH,

May 3, 2019 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

May 1, 2019 EX-99.1

Tetra Tech Reports Record Second Quarter 2019 Results

EX-99.1 2 a19-91671ex99d1.htm EX-99.1 Exhibit 99.1 NEWS RELEASE May 1, 2019 Tetra Tech Reports Record Second Quarter 2019 Results · Record net revenue of $585 million, up 10% Y/Y · Record backlog of $2.81 billion, up 12% Y/Y · EPS $1.00; adjusted EPS $0.70, up 30% Y/Y · Increased quarterly dividend by 25% to $0.15 Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK) today announced results for th

May 1, 2019 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 1, 2019 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Number)

March 1, 2019 8-K

Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): February 28, 2019 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File N

February 12, 2019 SC 13G/A

TTEK / Tetra Tech, Inc. / VANGUARD GROUP INC Passive Investment

tetratechinc.htm - Generated by SEC Publisher for SEC Filing SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 8 )* Name of issuer: Tetra Tech Inc Title of Class of Securities: Common Stock CUSIP Number: 88162G103 Date of Event Which Requires Filing of this Statement: December 31, 2018 Check the appropriate box to desig

February 8, 2019 SC 13G/A

TTEK / Tetra Tech, Inc. / DIMENSIONAL FUND ADVISORS LP - SCHEDULE 13G/A Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 3)* TETRA TECH INC (Name of Issuer) Common Stock (Title of Class of Securities) 88162G103 (CUSIP Number) December 31, 2018 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule

February 1, 2019 10-Q

TTEK / Tetra Tech, Inc. 10-Q (Quarterly Report)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ý QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended December 30, 2018 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TEC

February 1, 2019 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

January 30, 2019 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

8-K 1 a19-367918k.htm 8-K UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 30, 2019 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorpor

January 30, 2019 EX-99.1

Tetra Tech Reports Record First Quarter 2019 Results

EX-99.1 2 a19-36791ex99d1.htm EX-99.1 Exhibit 99.1 NEWS RELEASE January 30, 2019 Tetra Tech Reports Record First Quarter 2019 Results · Record operating income of $56 million, up 15% Y/Y · Record backlog of $2.79 billion, up 15% Y/Y · EPS $0.75; adjusted EPS $0.70, up 8% Y/Y Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK) today announced results for the first quarter ended December 30, 2018.

January 18, 2019 DEFA14A

TTEK / Tetra Tech, Inc. DEFA14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) o Defin

January 18, 2019 DEF 14A

TTEK / Tetra Tech, Inc. DEF 14A

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ý Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14

November 16, 2018 10-K

TTEK / Tetra Tech, Inc. 10-K (Annual Report)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended September 30, 2018 or ¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number 0-19655 TETRA TECH, INC.

November 16, 2018 EX-21

Subsidiaries of the Company.

Exhibit 21 Subsidiaries of Tetra Tech, Inc. NAME JURISDICTION OF FORMATION Advanced Management Technology, Inc. Virginia American Environmental Group, Ltd. Ohio America's Schoolhouse Consulting Services, Inc. New York ARD, Inc. Vermont Ardaman & Associates, Inc. Florida BIOCNG, LLC New York Coffey UK Limited United Kingdom Cornerstone Environmental Group, LLC New York Cosentini Associates, Inc. Ne

November 16, 2018 EX-95

Mine Safety Disclosures.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

November 7, 2018 EX-99.1

Tetra Tech Reports Fourth Quarter and Fiscal 2018 Results

Exhibit 99.1 NEWS RELEASE November 7, 2018 Tetra Tech Reports Fourth Quarter and Fiscal 2018 Results · Record annual revenue of $2.96 billion, up 8% Y/Y · Record quarterly cash flow from operations of $109M, up 65% Y/Y · Record backlog of $2.66 billion, up 9% sequentially · Q4-18 EPS $0.51; Record quarterly ongoing EPS $0.75, up 19% Y/Y Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK) today a

November 7, 2018 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): November 7, 2018 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction (Commission (IRS Employer of incorpor

August 8, 2018 SC 13G/A

TTEK / Tetra Tech, Inc. / VANGUARD GROUP INC Passive Investment

tetratechinc.htm - Generated by SEC Publisher for SEC Filing SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 7 )* Name of issuer: Tetra Tech Inc Title of Class of Securities: Common Stock CUSIP Number: 88162G103 Date of Event Which Requires Filing of this Statement: July 31, 2018 Check the appropriate box to designate

August 3, 2018 S-8

TTEK / Tetra Tech, Inc. S-8

As filed with the Securities and Exchange Commission on August 3, 2018 Registration No.

August 3, 2018 10-Q

TTEK / Tetra Tech, Inc. 10-Q (Quarterly Report)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ý QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended July 1, 2018 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH, IN

August 3, 2018 EX-95

Mine Safety Disclosure.

EX-95 6 ttekex95q32018.htm EXHIBIT 95 Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.S. mines that is subject to the Federal Mine Safety and Health Act of 1977 (“MSHA”), the information required by Section 1503(a) of the Dodd-Frank Wall Street Reform and Consumer Protection Act and Item 104 of Regulation S-K. Section references are to sections of MSHA

August 1, 2018 EX-10.1

Second Amended and Restated Credit Agreement dated as of July 30, 2018 among Tetra Tech, Inc., Tetra Tech Canada Holding Corporation, Coffey UK Limited, Coffey Services Australia Pty. Ltd., the lenders party thereto and Bank of America, N.A., as Administrative Agent (incorporated by reference to Exhibit 10.1 to the Company's Current Report on Form 8-K dated August 1, 2018).

EX-10.1 2 a18-180071ex10d1.htm EX-10.1 Exhibit 10.1 EXECUTION VERSION Published Deal CUSIP Number: 88163BAF0 Revolving Credit Facility CUSIP Number: 88163BAG8 Term Loan Facility CUSIP Number: 88163BAH6 SECOND AMENDED AND RESTATED CREDIT AGREEMENT Dated as of July 30, 2018 among TETRA TECH, INC., TETRA TECH CANADA HOLDING CORPORATION, COFFEY UK LIMITED, COFFEY SERVICES AUSTRALIA PTY. LTD. and CERTA

August 1, 2018 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Entry into a Material Definitive Agreement, Material Modification to Rights of Security Holders, Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): July 30, 2018 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Numbe

August 1, 2018 EX-99.1

Tetra Tech Reports Third Quarter 2018 Results

EX-99.1 3 a18-180071ex99d1.htm EX-99.1 Exhibit 99.1 NEWS RELEASE August 1, 2018 Tetra Tech Reports Third Quarter 2018 Results · Record revenue of $765 million, up 12% Y/Y · Record net revenue of $570 million, up 14% Y/Y · Record operating income of $55 million, up 21% Y/Y · EPS $0.59; Record ongoing EPS $0.71, up 34% Y/Y Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK) today announced results

May 4, 2018 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

May 4, 2018 10-Q

TTEK / Tetra Tech, Inc. 10-Q (Quarterly Report)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ý QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended April 1, 2018 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TECH, I

May 2, 2018 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): May 2, 2018 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Number)

May 2, 2018 EX-99.1

Tetra Tech Reports Second Quarter 2018 Results

EX-99.1 2 a18-125281ex99d1.htm EX-99.1 Exhibit 99.1 NEWS RELEASE May 2, 2018 Tetra Tech Reports Second Quarter 2018 Results · EPS $0.51; Ongoing EPS $0.54, up 13% Y/Y · Increased quarterly dividend to $0.12 per share, up 20% · Increasing net revenue guidance for FY18; midpoint up 8% Y/Y · Increasing EPS guidance for FY18; midpoint up 20% Y/Y Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK) to

March 9, 2018 EX-10.1

Change of Control Severance Plan effective March 26, 2018 (incorporated by reference to Exhibit 10.1 to the Company's Current Report on Form 8-K dated March 9, 2018).*

EX-10.1 2 a18-78261ex10d1.htm EX-10.1 Exhibit 10.1 TETRA TECH, INC. CHANGE OF CONTROL SEVERANCE PLAN (Effective March 26, 2018) TETRA TECH, INC. CHANGE OF CONTROL SEVERANCE PLAN SECTION 1 Purpose 1.1 Purpose. The Tetra Tech, Inc. Change of Control Severance Plan (the “Plan”) has been established by Tetra Tech, Inc. (the “Company”), effective as of March 26, 2018, to promote the long-term financial

March 9, 2018 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): March 8, 2018 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction (Commission (IRS Employer of incorporati

February 12, 2018 SC 13G/A

TTEK / Tetra Tech, Inc. / VANGUARD GROUP INC Passive Investment

tetratechinc.htm - Generated by SEC Publisher for SEC Filing SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 6 )* Name of issuer: Tetra Tech Inc Title of Class of Securities: Common Stock CUSIP Number: 88162G103 Date of Event Which Requires Filing of this Statement: December 31, 2017 Check the appropriate box to desig

February 9, 2018 SC 13G/A

TTEK / Tetra Tech, Inc. / DIMENSIONAL FUND ADVISORS LP - SCHEDULE 13G/A Passive Investment

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. 2)* TETRA TECH INC (Name of Issuer) Common Stock (Title of Class of Securities) 88162G103 (CUSIP Number) December 31, 2017 (Date of Event Which Requires Filing of this Statement) Check the appropriate box to designate the rule pursuant to which this Schedule

February 1, 2018 EX-95

Mine Safety Disclosure.

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

February 1, 2018 10-Q

TTEK / Tetra Tech, Inc. 10-Q (Quarterly Report)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q (Mark One) ý QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended December 31, 2017 OR o TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number 0-19655 TETRA TEC

January 31, 2018 EX-99.1

Tetra Tech Reports Strong First Quarter 2018 Results

EX-99.1 2 a18-39201ex99d1.htm EX-99.1 Exhibit 99.1 NEWS RELEASE January 31, 2018 Tetra Tech Reports Strong First Quarter 2018 Results · Record quarterly revenue of $760 million, up 14% year over year · Operating income of $49 million, up 22% year over year · EPS of $0.81; ongoing EPS of $0.65, up 33% year over year Pasadena, California. Tetra Tech, Inc. (NASDAQ: TTEK) today announced results for t

January 31, 2018 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 31, 2018 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

January 30, 2018 EX-24

EX-24

EX-24 2 prestonhopsoniii01222018.htm POA HOPSON

January 24, 2018 DEFA14A

TTEK / Tetra Tech, Inc. DEFA14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant x Filed by a Party other than the Registrant o Check the appropriate box: o Preliminary Proxy Statement o Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) o Defin

January 24, 2018 DEF 14A

2018 Equity Incentive Plan (incorporated by reference to the Company's Proxy Statement for its 2018 Annual Meeting of Stockholders held on March 8, 2018).*

Use these links to rapidly review the document TABLE OF CONTENTS Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.

January 22, 2018 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported): January 22, 2018 TETRA TECH, INC. (Exact name of registrant as specified in its charter) Delaware 0-19655 95-4148514 (State or other jurisdiction of incorporation) (Commission File Nu

November 20, 2017 EX-21

Subsidiaries of Tetra Tech, Inc.

Exhibit 21 Subsidiaries of Tetra Tech, Inc. NAME JURISDICTION OF FORMATION Advanced Management Technology, Inc. Virginia America's Schoolhouse Consulting Services, Inc. New York American Environmental Group, Ltd. Ohio ARD, Inc. Vermont Ardaman & Associates, Inc. Florida Arlington Power Consulting Limited Nigeria BFP Consultants Pty Ltd Australia BIOCNG, LLC New York Bovell Freeman Holley (Pty) Ltd

November 20, 2017 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Fiscal Year Ended October 1, 2017 or ¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the Transition Period from to Commission File Number 0-19655 TETRA TECH, INC. (E

November 20, 2017 EX-10.6

AMENDMENT NO. 5 TO CREDIT AGREEMENT

Exhibit 10.6 AMENDMENT NO. 5 TO CREDIT AGREEMENT This AMENDMENT NO. 5 TO CREDIT AGREEMENT dated as of September 1, 2017 (this ?Amendment?), is among TETRA TECH, INC., a Delaware corporation (the ?Company?), TETRA TECH CANADA HOLDING CORPORATION, a Canadian corporation (together with the Company, collectively, the ?Borrowers?), BANK OF AMERICA, N.A., in its capacities as the Administrative Agent (i

November 20, 2017 EX-95

MINE SAFETY DISCLOSURES

Exhibit 95 MINE SAFETY DISCLOSURES The following table shows, for each project performed at U.

November 15, 2017 EX-24

EX-24

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November 15, 2017 EX-24

EX-24

poarynnin

November 15, 2017 EX-24

EX-24

poaauman

November 15, 2017 EX-24

EX-24

EX-24 2 poaargus.htm POA ARGUS 1

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