I have this strange, odorless sticky orange/brown goo slowly oozing from the main sewer pipe out of the house in the basement. It has taken months, possibly years to biuld up, but has become noticeable recently. It looks like candle wax has been dripped on the side of the pipe. I had a plumber look at it today. He did not know what it was but said not to worry unless water leaking, or smelled like sewage. Any thoughts! :confused: