Approximately 400 billion gallons of water are used in the United States every day, and a small portion of this water sometimes becomes contaminated from various human activities, such as farming, urban runoff, and factory spills or leaks. A water treatment process is needed in the case of making contaminated water suitable for use. However, sometimes water is not needed in some instances, and dewatering systems are installed.
Dewatering is the process of removing water from solid materials and soil in order to make way for excavation, foundations, shoring, or to lower the water table. Also knowns as construction dewatering, this is not a water treatment process to clean water, but to instead more water.
Some dewatering systems include pumps, centrifugal pumps, eductors, or vacuums. Deep wells are often used in mine dewatering systems and consist of boreholes containing slotted linings and electric submersible pumps, which pump water from the well. As this water is pumped out, a gradient is formed into which the water flows into, leaving no water remaining in the pore spaces found in the soil.
Wellpoints are also used in construction dewatering. These consist of small (50 mm) tubes with slots near the botton. These wellpoints are inserted into the ground and water is then drawn out by a vacuum generated by a dewatering pump. These wellpoints are often used on the perimeter of an excavation site and have the ability to drain water levels by up to five meters.
Horizontal drainage is simple to install and is often used for basement dewatering systems. A construction worker will install a pipe, followed by a synthetic perforated pipe into which the water will flow. The drain pipe is connected to a drain which collects the water that runs along the pipe thanks to gravity. After gravity does its job in carrying the water away from the site, construction can start.
Dewatering systems are mostly used in the construction industry, but they can also be used in the water treatment process by bringing water to the surface to be treated with chemicals. It is important to understand that these systems only offer temporary reductions in groundwater levels.
Have you ever wondered how a dam is created? These dewatering systems are used to prevent water from coming into the construction site, yet once the dam is built, the water is released back into the porous soil. Sometimes it can be cost effective to permanently keep groundwater out of a finished site. Sludge dewatering systems are often used in this case, as well as a water treatment process.
During the wastewater treatment process, a watery sludge is created as a byproduct. Getting rid of this sludge is often very costly. In this case, sludge dewatering systems provide an excellent way to get rid of the sludge by dehydrating the solid byproduct. Dehydrating this sludge reduces it’s weight and volume, allowing for better storage and removal.
The benefits of dewatering systems is that they, for the most part, do not permanently displace the water. As a result, they keep the existing environment in tact.
