Record safely
Note whether the odor is inside or outside, whether it follows water use and whether any backup or wet area accompanies it. Stay away from openings and enclosed septic spaces. Never enter a tank or lean over an open access point.
Assessment questions
Ask what components and conditions the inspection can cover and what findings would require plumbing work instead. The smell alone cannot establish the tank's contents or prove that the drainfield has failed.
Agree on next steps
Request an explanation of any proposed pumping, repair or further assessment. Clarify which work addresses a confirmed cause and which work is exploratory.
Before booking
Mention any indoor sewage backup or alarm along with the odor so the provider can assess the appropriate response.