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    PUBLIC DOCUMENT COUNT:		35
    CONFORMED PERIOD OF REPORT:	20180308
    FILED AS OF DATE:		20180124
    DATE AS OF CHANGE:		20180124
    EFFECTIVENESS DATE:		20180124

    FILER:

    	COMPANY DATA:
    		COMPANY CONFORMED NAME:			TETRA TECH INC
    		CENTRAL INDEX KEY:			0000831641
    		STANDARD INDUSTRIAL CLASSIFICATION:	SERVICES-ENGINEERING SERVICES [8711]
    		IRS NUMBER:				954148514
    		STATE OF INCORPORATION:			DE
    		FISCAL YEAR END:			0928

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    		SEC ACT:		1934 Act
    		SEC FILE NUMBER:	000-19655
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    		CITY:			PASADENA
    		STATE:			CA
    		ZIP:			91107
    		BUSINESS PHONE:		6263514664

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    		STATE:			CA
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