Yesterday during very heavy rain my basement flooded from water coming out of the toilet. The water was fairly clear and did not smell (there was very minimal solid waste). I called the city and they told me to call them back if it happens again. Apparently they received hundreds of calls that day. One plumbing company I called suggested I may have a partially blocked sewer line? I may have a combination sanitary and storm line.

How can I diagnose and correct the problem? Could the water be my rain water? Could it be the city sewer water? Help! Thanks for your suggestions!



Post Edited (07-07-03 16:34)

A sewer camera may answer most of your questions. 100 year rains are the ones that cause all of those un-expected problems. The city line can only hold so much water/waste/storm water, before nature kicks in and gravity takes over.
Be glad that it only should happen once every 100 years.
May you live to be a 1000 !

it could be a blockage. but this is why in the modern age of plumbing systems, there should be a seprate system for storm, and waste water. are u in a big city like boston ma.??? this is common in the downtown areas, because the storm drainage ties into the waste water drainage, and is undersized for heavy rain, and the amount of lines tied into the system over the years.
i would suggest installing a back water valve for this basement bath. it is required in alot of areas. it acts like a check valve, so waste can go out, but it should keep the outher bad stuff from coming back into your home.

good luck.

Maybe it is a partial blockage. I am not sure if my storm drainage ties into the waste water drainage, but the fact that the water coming out was fairly clear and without a smell makes me believe it is a combined system.
If I install this back water valve, I would have to do the same for the laundry drain and the bathroom sink which had some water came up, but did not overflow. Is there another alternative? How about diverting some of the rain water outside and away from the house?

u would put this backwater valve on the building drain. this is the line that leaves your home, and ties into the city system. if u put this valve in the building drain to your home, it should take care of any backflow trying to get into your home. u will need to pull a permit for this, and should be installed by a licensed plumber. good luck.

If your city had 100's of calls about basement toilets backing up, it's extremely unlikely that all those homeowners had partially obstructed sewer lines. (More likely, it's impossible that so many individuals had the exact same problem in their home systems at the exact same time) Far more likely is that the city sewer system was overloaded by rain pouring into it, and the resultant high pressures caused backups all over. The commonest cause is too much rain water getting into the sewer system. It may have nothing to do with your house. If there is enough fluid getting into the sewer from whatever source, sewers will back up. There are a lot of products for sewer backup prevention at the individual home owner level, but I don't know how effective they are. My own plumber doesn't use any method in his own home, if that's any indication of the value of such systems. My city forbids new construction from allowing storm or sump drainage into the sewers, but most homes in the city are over 30 years old, and the great majority of homes do drain rainwater directly into the sewers through their downspouts and footing drains. My city mandates sump pumps in all new residential housing, and sewer backup prevention valves in all businesses, but not in new residences. If you've followed my discussion, my city's measures do not really address the problem, since most of the older homes are the cause of the problem of the excess demand on the sewers during heavy rains. Some cities do have programs promoting the disconnection of storm drainage from the sewers, no matter what the age of the dwelling.