Theresa Bellish headshot

Theresa Bellish

Senior Global Managing Director

Commercial Water Systems

North America

Theresa Bellish has two decades of experience in testing, auditing and certification services for drinking water treatment chemicals, distribution system components, recreational water products,onsite waste water treatment systems and electrical safety services. She began her career with NSF International in 2000 and has held several leadership positions in NSF’s Water division, including roles as Business Unit Manager for water distribution system components and for recreational water products.

Previously, Ms. Bellish served as Senior Certification Project Manager, where her technical knowledge and product management skills helped promote the business operations of municipal drinking water and recreational water products certification. Earlier in her career, she served as a microbiological control analyst for a pharmaceutical company, helping to test, monitor and validate laboratory analyses.

Ms. Bellish is a member of the American Water Works Association and the Water Environment Federation.

Her areas of expertise include:

  • Strategic planning
  • Water treatment and quality
  • Program management
  • Environmental awareness and compliance