Four Tight Gravity Sites




Here are four design strategies to help you if you require a compact gravity septic
design for a too-small lot. In certain areas, especially on older plats, this
problem is eternal. The goal, of course, is to fit a large house, plus a garage/or shop,
underground utilities, AND the septic system, all within the property lines of a small,
tight, urban sized residential lot. You can always lose a parking space or even a room in the
house, but the drainfield area is incompressible space, and so is the replacement area.
It is a puzzle sometimes fitting the house, parking, driveways, patios, water service, and all of
the other common site elements, within and around the septic trenches, without running across
someone else’s tracks. Minimum setbacks in these situations are critical. Setbacks must be
included between the drainfield, any buildings, the replacement area, property lines and
easements. Even the setbacks between individual trenches can make or break your layout
plans when every inch or centimeter counts. Study these designs for a few tricks of the trade.