I have an exterior drain leak. Water seeping up thru ground. Upon inspection I have 3 kitchen 2″ cast iron drains leaving the house and entering what appears to be a grease pit (circular underground cistern of some kind with a stone lid). I think the line out of this cistern needs to be snaked since it looks like the cistern is filling up and overflowing into the surrounding dirt. Any suggestions? Should I bypass the cistern after I clean out the line and tie all three kitchen drains directly into the line exiting the cistern? The house is about 100 yrs old and these lines look original. I think many home drains in our neighborhood were plumbed this way originally but I think the cistern is generally considered unnecessary nowadays.
kerryedwards, the container that you refer to as a cistern is actually a grease trap. A cistern is a tank for the storage of clean water or rain water. If the grease trap is still functional after cleaning the tank and discharge pipe, I suggest that you maintain the plumbing system as it is. It matters not whether you are served by a septic system or a centralized sewer system, for Fat, Oil, and Grease (FOG) are detrimental to the treatment processes involved in either of these sewage treatment systems.