<SEC-DOCUMENT>0000834237-20-002807-index.html : 20200204
<SEC-HEADER>0000834237-20-002807.hdr.sgml : 20200204
<ACCEPTANCE-DATETIME>20200204123055
ACCESSION NUMBER:		0000834237-20-002807
CONFORMED SUBMISSION TYPE:	SC 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20200204
DATE AS OF CHANGE:		20200204

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:			0927

	FILING VALUES:
		FORM TYPE:		SC 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-43035
		FILM NUMBER:		20572271

	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:			BlackRock Inc.
		CENTRAL INDEX KEY:			0001364742
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY BROKERS, DEALERS & FLOTATION COMPANIES [6211]
		IRS NUMBER:				320174431
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		55 EAST 52ND STREET
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10055
		BUSINESS PHONE:		212-810-5300

	MAIL ADDRESS:	
		STREET 1:		55 EAST 52ND STREET
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10055

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BlackRock, Inc.
		DATE OF NAME CHANGE:	20060929

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	New BlackRock, Inc.
		DATE OF NAME CHANGE:	20060601
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13G/A
<SEQUENCE>1
<FILENAME>us88162g1031_020320.txt
<TEXT>
Document 1 - file: us88162g1031_020320.txt

</DOCUMENT>
</SEC-DOCUMENT>