The Department of Environmental Protection (MassDEP) Underground Storage Tank (UST) Third-Party Inspector (TPI) Certification Program ensures that those responsible for inspecting UST systems have the necessary qualifications and experience. Qualified individuals are certified for five years and need to apply for renewal at least 90 days before their current certifications expire. 

Please Note: If you are a TPI registered before January 2, 2015, please contact MassDEP at before you start your new application.

TPI Qualifications & Certification

To become a MassDEP-certified UST Third-Party Inspector, you must: 

  • Document that you:
    • Have a minimum of five (5) years of experience in the field of UST installation and/or operation and maintenance. (you may substitute a bachelor's or associate's degree in science or engineering for two (2) years of experience); and
    • Either (1) assisted a registered/certified third-party inspector perform at least ten inspections within the past three years, or (2) hold a third-party inspector certification from another state and have performed a minimum of ten third-party inspections in that state within the past three years.
  • Take and pass the MassDEP Third-Party Inspector Certification Exam.
    • Visit this web site and follow the prompts to register, pay the exam fee of $75, and take your exam.
    • If you are a new user, you will need to create an account first.
    • Exams are available online 24 hours a day and are "open book," but must be completed in one sitting and within the allotted running time.
    • Computer support is available at all times.
    • Your results will displayed immediately after you answer the last question or run out of time. 
    • MassDEP will receive your results from the exam vendor. 
    • This exam is based on the MassDEP regulations: 310 CMR 80.00: Underground Storage Tank (UST) Systems  pdf format of 310 CMR 80.00: UST Systems
  • Submit your completed UST/TPIN: New Third-Party Inspector Certification  doc format of UST/TPIN: New Third-Party Inspector Certification
pdf format of                             UST/TPIN: New Third-Party Inspector Certification                form, along with exam results and other required documentation, via email to MassDEP:

MassDEP will review your completed application, including documentation of credentials, as well as your exam results and will certify you as a UST Third-Party Inspector if you meet all requirements.

Maintaining Your Certified UST Third-Party Inspector Status

Once MassDEP issues you a TPI Certification:

  • Your certification belongs to you, not your employer.
  • You will be required to attend MassDEP-sponsored annual training.
  • You must perform inspections according to the provisions of 310 CMR 80.48(10) and 310 CMR 80.49. See: 310 CMR 80.00: Underground Storage Tank (UST) Systems  pdf format of 310 CMR 80.00: UST Systems
  • You must renew your certification every five years.