The only way to know the condition of your underground sanitary service is to have a pipe inspection completed to see what’s going on inside your pipe.  We recommend having your pipe inspected: Before purchasing any new or older property (even in new home purchases improper installation methods have been found) If you are experiencing back-ups and/or have your line cleaned regularly due to known issues If your home was built prior to 1990 (pipe materials do not last forever, in older areas some of the pipes in Calgary are tar paper pipes (No-corrode/Orangeburg Pipe) If you are experiencing sewage or water back-ups inside your basement (showers, floor drains etc.) regardless how minor, there is likely an issue inside your pipe. Even if you have not yet experienced a back-up your pipe may be deteriorating underground and one day you could get a very unpleasant surprise.  Just as you would have your roof or furnace inspected, your sewer also needs to be checked out from time to time. Especially if you have known problems in the line already (roots, sags etc.) as these can worsen over-time and cause big problems. We recommend every 3-5 years to keep an eye on deteriorating pipe condition.