A sump pump, such as one supplied by your plumbing contractor, is a small pump installed in the lowest part of a basement or crawlspace. A professional will tell you that the purpose of a sump pump is to keep the area under the building dry and to prevent it from flood­ing. When the water table around a home rises, flooding occurs. The upper surface of ground water is called the water table.

Below this water surface, all the cracks and sediment are saturated with water. These saturated layers are where ground water is. If your basement is built below the water table line, water can get find its way in. If you discover your recreation room furniture submerged one day, you'll need to call on a plumbing contractor to determine the leakage source.

Sump pumps are usually installed in an area called a sump pit, constructed for just that purpose. Most reputable plumbing contractors can do this work for you. Water flows into the sump pit either through drains or naturally via water movement through the soil. The sump pump's job is to pump the water out of the pit and away from the building so the basement or crawlspace stays dry.

Here's how a sump pump works. The pit hole with the pump in it has a gravel base which is about 2 feet deep and 18 inches wide. When the pit fills with water, the pump automatically goes on. It pushes the liquid out of the pit through pipes that drain away from your home to an area where the water can drain away from your foundation. The pipe usually has a one-way valve, called a check valve, at the end of the pump to keep the water from flowing back into the pit.

Most sump pumps have a pressure valve or float activator. When water puts more pressure on the pressure valve than the air does, the pump goes on. It works in a similar way to the float in your toilet tank, using centrifugal force to move the water out. An automatic pump, goes on when the valve senses water without you having to do anything.

There are also manual pumps which you can turn on yourself when needed. The manual pumps are definitely not as popular because it is much more convenient not to have to worry about monitoring the situation constantly. The sump pumps use electricity to work.Therefore it is an extremely good idea to get one with a backup installed in case you lose electricity during a storm.

It is during a severe storm when flooding tends to happen. The backup power comes from a car battery or a deep cycle boat battery. Most of the systems are constantly charging the battery while the power is on, making sure the battery is fully charged in the event of a power outage. Wouldn't it be nice to have the peace of mind of a hard working sump pump complete with battery backup?