X0303 4 2010-02-05 0000831641 TETRA TECH INC TTEK 0001450067 SHOEMAKER LESLIE L 3475 EAST FOOTHILL BOULEVARD PASADENA, CA 91107 0 1 0 0 VICE PRESIDENT COMMON STOCK 2009-12-31 4 A 0 216 23.09 A 20307 D COMMON STOCK 2010-02-05 4 P 0 3000 20.805 A 23307 D Consists of 216 shares acquired under the Tetra Tech, Inc. Employee Stock Purchase Plan (an exempt transaction under Rule 16b-3(c)). DAVID W. KING for LESLIE L. SHOEMAKER 2010-02-09