Per my town building inspector in Northeast NJ, code no longer requires a 4†cast iron DWV pipe that rises up from my house’s main Drain-Waste-Vent pipe just before it exits my house. Is there any reason to keep this pipe? I need to cut and cap it, or cut and replace it with re-routed PVC, so I can have an electrician replace my electrical service (the cast iron is about 2’ from my fuze boxes). My approx. 100-year old 3-story (3-apartment) house has a vertical cast iron DWV pipe that penetrates my roof and which the 4 bathrooms tie into. This main DWV pipe leads into the horizontal one under my basement slab, which then runs about 40’ where this “extra†vent pipe and then 2 clean-outs rise up from the horizontal DWV pipe just before it exits my house. This apparent “extra†vent pipe rises straight up approx. 5’, then runs horizontally about 6’ where it exits my house through an above ground penetration in the side of my foundation. I assume it’s 4†cast iron buried under my slab since everything else above the basement slab is cast iron, but I was told the pipe from my house to the city sewer is clay pipe. If current plumbing code does not require this “extra†vent pipe, is there still good reason to replace it with PVC instead of just capping it? I assume the original installers did it for a reason. Does it significantly help the flow of waste and help prevent my old clay pipe from getting clogged? Is it an emergency escape path for sewage if the sewer feed pipe does clog - letting the waste flow out of the side of your house instead of out of a first-floor bathroom? If so, the later-installed basement bathroom renders this benefit useless. Regarding vent pipes, my house also has a 2 inch vent pipe that exits the roof above 2 kitchen sinks. Any feedback/suggestion would be greatly appreciated. Thanks, Craig