Tai-Dan Hsu, PhD, PE – CEO and Co-Owner

Dr. Tai-Dan Hsu is a co-founder and co-owner of PWT since it was incorporated in 1987. Dr. Hsu has more than 30 years of experience in water resources, environmental compliance, engineering design and cost analysis.

Ding-Wen Hsu, Executive MBA – Co-Owner and Division Manager 

Ding-Wen Hsu is co-founder and majority shareholder of PWT. Ms. Hsu has more than 40 years of MIS and managerial experience. Currently she is the Director of PWT’s Federal Facility Management Division.


Aaron Baird – PWT Project Manager and EarthFax Engineering Group LLC Group Manager

Aaron is a senior environmental scientist and project manager with over 20 years of environmental consulting experience working for state, federal, and private industry clients. Aaron’s expertise is in project management, remedial investigations, remedial action implementation, and supervision of field operations. Aaron is the head of PWT’s Utah office and currently manages four CERCLA sites in Utah and Montana. Aaron is also the group manager for PWT’s Utah-based subsidiary, EarthFax Engineering Group, which is a multifaceted engineering and environmental consulting firm servicing commercial, industrial, and government clients.

Billy Lee – Controller

Mr. Billy Lee is responsible for the overall financial and accounting aspects of PWT. He has over 32 years of experience in Finance and Accounting. He is fully competent in all aspects of financial accounting, business administration, budgeting, cost control, payroll, accounts payable, client and audit liaison.

Stephen Singer, PG, PMP – Program Manager

Program manager for EPA’s Unified Remediation Oversite and Rocky Mountain Arsenal Oversite Contracts and is project manager for multiple projects under the EPA Remedial Action Contract for Region 8. Mr. Singer is a PMI certified project manager and has over 30 years of experience in superfund projects in Colorado, Montana and Utah. Primary areas of expertise include Remedial Investigations, RI/FS and RD/RA oversight, geology/hydrogeology, database management and GIS as applied to sites with volatile organic, pesticide, heavy metal and radionuclide contamination.

Bruce Peterman, PE, PG, PMP, MCSE – Project Manager, Senior Engineer, IT Manager

Bruce is a senior geological engineer and project manager with more than 30 years of experience with investigations and remediation project in hydrogeology, geology, engineering, geotechnical, construction management, project planning, groundwater, and mining related mitigation. Professional Engineer in Colorado and Professional Geologist in Wyoming and Florida. Expertise in Information Technology (IT) systems and geographical information systems. Maintains corporate IT assets, network infrastructure, operations, technical upgrades, and outside vendors for PWT.