I live in a condo building that has a sump pit for collecting rain water only(no solid waste) from front and back patios and downspouts. In that pit are two 1/2 hp sump pumps that pump out into a single 1.5" copper pipe (2 pipes join together with 'Y' fitting) that rises around 10 - 15 feet and out (overhead plumbing in building).
My question is this: Does the 1.5" copper pipe have enough capacity to handle the outflow from both pumps running full out during a heavy rainstorm?
A few times a year, the pit becomes overwhelmed and I need to run a hose out to the street and drop an extra pump into the pit to keep from flooding. Water level in pit rises above level of inflow pipe, so water starts backing up into patios and water starts to leak into to sliding glass door in rear of my condo. So, do I need a wider pipe to handle the outflow, or a third pump with a second outflow pipe to handle things? I freak out every time we have a severe thunderstorm warning.