Exterior home sump pumps installed in sump wells
Exterior sump pump installations can be the answer for homes that need to move lots of groundwater quickly. The premise of necessity in this case is to pump the groundwater because the amount of groundwater to deal with exceeds the ability of a conventional hand excavated drywell to perk the groundwater into the ground.
You may find while hand excavating your drywell that lots of groundwater is held in the area the drywell needs of go. In that case, assuming you are not below grade to the flood zone and just pumping the river itself, use a hand held sump pump attached to a hose that can remove the groundwater as you excavate deeper to a depth of around 4 feet.
When you have reached the depth required, fill around the concrete cylinder, which are actually tiles, with 6″ river rock after placing a concrete cylinder on a 6″ deep rock base at the bottom. This will draw groundwater through the rock and clean it prior to pumping it out. The groundwater level in the hollow center of the sump well will rise at the same level as the outside of the cylinders.
Level the cylinders, and install them by placing river rock around them to the top.
Build up your cylinders to within 1″ of the grade level after mounting your sump pump inside the concrete “tiles” which look like cylinders.
Plumb the sump pump with 1 1/2″ abs pipe and vent to a daylighted vent, perhaps at the street.
Put a top on the installation also made of concrete, and provide underground electric power to the sump well. Install an all weather extension cord in a conduit of 3″ ads solid pipe, or 2″ pvc pipe, and plug it in to an all weather gfci plug recepticle with a weather head, at the side of the home. Under an overhang or patio cover is a nice place for this power source.
These sump pumps can be hardwired if you prefer. Note however that if the sump pump goes out, your costs to replace the sump pump will skyrocket.
Roll up the remaining sump pump cord and place it about 8″ under the top layer of rock surrounding the sump well. If a hand excavated french drain slopes to the sump well, place weed cloth over the 3/4″-1 1/2″ river rock and top it off with rock around the sump well, and over the hand excavated french drain.