Sump Wells and Discharges


Wells (aka: crock, basin, sump pit or well) serve as the collection basins that house the pump. The two most common types are pictured here. The well on the left has a corrugated body and an easy slip-off lid.

These are typically less preferred as they do not seal the moisture in the well from the surrounding room. The type on the right is made from a much thicker mold of plastic and has a sealed lid assembly and is much easier to level.

Wells are installed with their tops flush with the floor and generally go to a depth of 22’’ or more. In basement waterproofing the wells are commonly perforated with a 1/4’’ drill bit 30 or more times so that the well assembly itself will act as a catch for water. If the soil is not mud or clay and is sufficiently filled with gravel then this is a wise technique as the well sits lower than the rest of the drainage and will help to keep the water that much further from the floor.


The first thing installed in a discharge line should be a check valve to prevent the water that is ejected from returning into the well.

It is not advised and is often against code to discharge a sump pump into a sewer system or onto a sidewalk for safety reasons. Discharges should be sent at least 12 ft. or more away from the foundation wall. It is best to have discharge lines end at least 20 ft. from the house. Ideally the discharge line would be buried to prevent freezing and end in a catch basin that allows the water to slowly drain back in the ground. Buried discharges should be pitched downward to the catch basin. In colder climates discharges should have a freeze block (pictured on right) installed and the discharge should always be buried. This is important as frozen discharge lines will force water to back up into the sump well and possibly the floor.

Discharge lines should pitch away from the pump as soon as possible to prevent water from sitting in the line, freezing, stagnating, feeding critters etc. The discharge line is dependent on the thread on the pump outlet. The most common pipe size for discharge lines is 1.5″ and sometimes 2″. You should not take a pipe that is 2″ and fit it down to 1.5″ keep the discharge at the same size. Going larger is o.k. going smaller is not.






Catch Basins Or Discharge Wells
These are receptacles that collect water discharged outside versus simply pouring the water on the ground,patio, sidewalk etc. They also allow the water to drain further into the surrounding soil away from the house. This allows the pi pe to have constant free flow versus being blocked of clogged by dirt, snow or ice. The catch basin (picture right) is a very common solution to this problem. Although in areas where the ground freezes below 14’’ then a deeper discharge well should be used. These are pits dug 2+ ft. deep that the discharge enters into the side of. They are then filled with gravel and covered with a filter fabric to slow soil erosion into the pit. A vent pipe is then installed to the surface. The idea here is to get the discharge pipe to discharge farther below possibly frozen earth.