331camaro wrote:... i have what i think is a clean out pipe that has been broken in my lawn, can i put a cap on this 4'' pvc pipe or is this a breather?
Is the pipe sticking up vertically out of the ground? Or horizontal at ground level? I believe the pipes in a leach field sometimes are vented by a vertical pipe that looks like a candy cane or upside-down letter J, open at the end. I have occasionally seen pipes like that coming out of the ground at houses. I would not cap something like that without being very sure it is OK. Are septic designs filed with your town government when a permit is issued? Maybe you can check the design documents. Or contact a septic tank service company, or system designer, and ask.