You can bury underground electrical wire six inches deep—but only if you use a rigid metal electrical conduit. For rigid, non-metallic conduits, bury the wire at least 12 inches deep. If using an underground feeder cable rated for direct burial, you'll need to place it at least 18 inches deep, as it has no conduit for extra protection.

The best method for digging a trench depends on the scope of the project. For a short, shallow trench (less than 2 feet deep) in light, soft soil, digging by hand may be sufficient. However, digging by hand is labor-intensive, so consider the effort required. A machine trencher is the better option for longer trenches (over 100 feet), deeper ones, or when dealing with difficult soil conditions, such as rocky or hard ground, or obstructions like tree roots. A machine can save significant time and energy in these situations.

A perc test can take anywhere from one to eight hours to complete. The total time depends on factors like the amount of excavation required, the depth and width of the holes, and whether multiple test holes are needed. For a single hole, the process of filling it with water and monitoring the drainage rate usually takes less than an hour. Professionals can often complete the entire test in a single day. While it's possible to get results the same day, some companies may take a few days to provide the official report.

Professional installers often include a deep layer of crushed gravel under permeable pavers to allow more runoff to soak through into the soil below. Many installations will include multiple layers of gravel, with coarser aggregate at the base and finer aggregate that sits on top of that bottom layer. Above the gravel, you’ll often find coarse sand that helps reduce paver shifting over time. Some permeable paver designs include a water collection system set into the gravel layer to route runoff to a safe area for disposal.