Becoming a Certified Time of Sale Inspector

Application for Washtenaw County Time of Sale Inspector Certification (PDF)

The Washtenaw County Inspection at Time of Property Transfer Regulation (PDF), or Time of Sale regulation, states that prospective certified inspectors must demonstrate knowledge of construction practices and operational standards, as well as the causes and indicators of onsite water supply and sewage disposal system failures. 

The Washtenaw County Environmental Health Division has established the following minimum requirements for obtaining certification as an inspector of on-site water supply or septic systems:

  1. Minimum of a high school education or equivalent.
  2. Technical knowledge of on-site water supply and/or sewage disposal systems as demonstrated by:
    • Personal interview with Washtenaw County Environmental Health Division staff. Applicants will be evaluated as to specific work experience and knowledge related to construction practices and operational standards of on-site water supply and sewage disposal systems. Applicants will also be evaluated based on existing credentials such as Registered Well Driller, State Certified Inspector, Registered Sanitarian, and/or Professional Engineer. These credentials are not required, but may be used to help establish competency.
    • Passing a brief screening exam. This exam will evaluate applicants on their technical knowledge of on-site water supply and sewage disposal systems. 
  3. Applicants who do not demonstrate the necessary technical knowledge required to be a certified inspector may demonstrate proficiency by successfully completing of one of the following:
    • Inspector certification in the appropriate field by the National Sanitation Foundation. 
    • A course or certification in on-site water supply or sewage disposal that is accredited by the Michigan Department of Environment, Great Lakes & Energy.
    • A Time of Sale Technical Training Course and Exam administered by Washtenaw County Environmental Health Division staff.
  4. After demonstration of technical knowledge, candidates must successfully complete a Time of Sale Core Training Course and Exam which will include:
    • Requirements of the Time of Sale regulation
    • Washtenaw County procedures to implement the Time of Sale regulation
    • Water supply inspection protocol
    • Sewage system inspection protocol
  5. Once the candidate completes the Time of Sale Core Training Course and Exam and pays the associated fees, they will be considered officially certified and will be allowed to perform Time of Sale inspections in Washtenaw County. Certified individuals will also be included on the list of Washtenaw County Certified Time of Sale Inspectors (PDF). Certified individuals are required to renew their certification annually, by submitting a renewal application and certification fee.