<SEC-DOCUMENT>0001258897-17-001248-index.html : 20170209
<SEC-HEADER>0001258897-17-001248.hdr.sgml : 20170209
<ACCEPTANCE-DATETIME>20170209102156
ACCESSION NUMBER:		0001258897-17-001248
CONFORMED SUBMISSION TYPE:	SC 13G
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20170209
DATE AS OF CHANGE:		20170209

SUBJECT COMPANY:	

	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

	FILING VALUES:
		FORM TYPE:		SC 13G
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-43035
		FILM NUMBER:		17585350

	BUSINESS ADDRESS:	
		STREET 1:		3475 EAST FOOTHILL BOULEVARD
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91107
		BUSINESS PHONE:		6263514664

	MAIL ADDRESS:	
		STREET 1:		3475 EAST FOOTHILL BOULEVARD
		CITY:			PASADENA
		STATE:			CA
		ZIP:			91107

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			DIMENSIONAL FUND ADVISORS LP
		CENTRAL INDEX KEY:			0000354204
		STANDARD INDUSTRIAL CLASSIFICATION:	UNKNOWN SIC - 0000 [0000]
		IRS NUMBER:				222370029
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G

	BUSINESS ADDRESS:	
		STREET 1:		6300 BEE CAVE ROAD
		STREET 2:		BUILDING ONE
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78746
		BUSINESS PHONE:		(512) 306-7400

	MAIL ADDRESS:	
		STREET 1:		6300 BEE CAVE ROAD
		STREET 2:		BUILDING ONE
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78746

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	DIMENSIONAL FUND ADVISORS INC
		DATE OF NAME CHANGE:	19920929
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G
<SEQUENCE>1
<FILENAME>dfs449.htm
<DESCRIPTION>SCHEDULE 13G
<TEXT>
Document 1 - file: dfs449.htm

</DOCUMENT>
</SEC-DOCUMENT>