A Septic System Inspection Should Be Done How Often?! Costs, Precautions, and MoreBy Margaret Heidenryracy A. Woodward/The Washington Post/Getty ImagesA septic system inspection is one of those home maintenance tasks that you might put off, and then put off some more. Because septics exist underground in the backyard, they are often out of sight, thus out of mind. But letting it go too many flushes...