Theresa Bellish

Senior Director
Water Systems

Theresa Bellish has over twenty years of experience in testing, auditing and certification services for drinking water treatment chemicals, distribution system components, recreational water products, onsite wastewater treatment systems and electrical safety services. She joined NSF in 2000 and has held several leadership positions, including roles as Business Unit Manager for water distribution system components and recreational water products.

Previously, Bellish served as Senior Certification Project Manager, providing her technical knowledge and product management skills to help with business operations. Additionally, she served as a microbiological control analyst for a pharmaceutical company, helping test, monitor and validate laboratory analyses.

Bellish is a member of AWWA, WEF & NOWRA.

Her areas of expertise include:

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