Tetra Tech | TTEK - Employees Total Number


Tetra Tech reported 25K in Employees for its fiscal year ending in December of 2025.





Employees Change Date
ABM Industries 117K 6K Oct/2024
AECOM 51K 1000 Sep/2024
Booz Allen Hamilton 34.2K 2.3K Mar/2024
Casella Waste Systems 5.1K 900 Dec/2024
CECO Environmental 1.2K 200 Dec/2023
Clean Harbors 22.8K 1.78K Dec/2024
Dycom Industries 15.61K 201 Jan/2024
Ecolab 48K 1000 Dec/2023
EMCOR 40.4K 2.1K Dec/2024
Enviri Corporation 13K 1000 Dec/2023
Exponent 1.17K 152 Dec/2025
Fluor New 26.87K 3.32K Dec/2024
Healthcare Services 33.4K 2.3K Dec/2023
ICF International 9.3K 300 Dec/2024
Jacobs Engineering 43K 2K Dec/2025
Leidos 48K 1000 Dec/2025
MasTec 33K 1000 Dec/2024
Mcgrath Rent 1.22K 15 Dec/2024
Mistras 4.8K 600 Dec/2023
MYR 8.5K 500 Dec/2024
Quanta Services 58.4K 5.9K Dec/2024
Quest Resource 195 2 Dec/2023
Rollins 20.26K 1.23K Dec/2024
SNC Lavalin 33.88K 2.89K Dec/2022
Stantec 26K 1000 Dec/2022
Team 5.4K 200 Dec/2023
Tetra Tech 25K 5K Dec/2025
WSP Global 66.2K 10.9K Dec/2022