The problem of finding space for a concrete patio and of concealing a septic tank are both solved by putting the patio on top of the septic tank. The procedure is a follows. One, lay out the patio over septic tank to fit available space. Two, plot location of tank entry port and plan design to be scored in concrete so that one square is directly over it. Three, frame off the opening. Four, construct a form the shape of the opening, but for a 3 /16 of an inch smaller all around. Five, score slab. Six, fit square into opening with a 3/16 inch space all around. Seven, when mortar hardens slightly, use straightedge and pointed tool to extend scoring across fresh mortar. Eight, patio may be screened as long as the septic pump equipment has a long hose extension.