I have a rental house in Falls Church, circa 1950s, where the main sewer clogged up about a month ago. I paid a guy what I thought was a huge amount to snake it out and run a camera down the line. He said he couldn't get the camera all the way to the main line in the street. Now the line is clogging up again, so I'm guessing repairs are needed in that vicinity. Apparently, the original cast iron line was replaced near the house, but not all the way to the main.