Types of Dewatering Systems

When excavating for new construction, the presence of surface and groundwater is a major concern. Whether it’s surface rainwater from a recent storm or groundwater in a deep excavation, removing water from your construction site helps to reduce slip hazards, minimize equipment damage, firm the soil, and eliminate the release of toxic materials into the surrounding environment.

Dewatering is the process of removing surface and groundwater from a construction site to enhance the safety and efficiency of the project site. At Triflo, we offer a variety of dewatering solutions that can be tailored to your project’s size, depth, location, and intended use. With more than 40 years in the industry, we specialize in developing innovative fluid processing solutions for our customers in the mining, drilling, construction, and other industries where clean excavation is critical. 

We are proud to offer four primary dewatering systems: well point, deep well point, eductor well, and open sump. Each offers unique advantages for particular applications. Well point systems are for shallow excavations in any soil, while deep well point systems are ideal for projects that must drill below ground in porous rock or soil. Eductor well systems are complex systems that provide unique assistance for deep excavations in poor-draining silt and clay. Sump pump systems are the least complex option, perfect for passive drainage of surface and shallow groundwater.

To find the perfect dewatering system for your needs, it is important to understand the uses and benefits of each system. Below, we provide a summary of each of the four systems, their advantages, and their ideal uses. 

Well Point System

A well point system offers a flexible, easy to install, and cost-effective dewatering solution. These systems consist of a series of shallow wells strategically drilled around the construction site, and pumps are placed into the wells. These small-diameter wells are connected by a header pipe to a central vacuum pump. The vacuum pump removes water from all of the wells in the system via the header pipe, creating an extremely efficient and highly effective water removal system.

Well point systems are ideal for shallow trenches, foundations, and utility excavations. When the excavation deepens beyond 15 feet,  additional well points can be installed at progressively deeper levels. The maximum depth for wells in well point systems depends heavily on the type of soil, the groundwater level, and the distance between wells. Well point dewatering systems are highly practical and effective in most soil types and hydrological conditions; however, deep well point systems may be more suitable for deeper excavations.

Deep Well Point System

Deep well point dewatering systems are for deeper excavations, particularly when there is a large volume of groundwater to remove. This method involves boring much deeper, more widely spaced wells. Each well contains an electric-powered submersible pump that is used to lower the groundwater level below the excavation level.

Deep well point systems are specifically designed to ensure safe, stable conditions in deeper excavations. They are ideal for use in soil and rock with a moderate to high level of permeability, such as sand and gravel. The wide spacing between each well allows for easy access during each stage of the excavation process and ensures the structural stability of each individual well.

Eductor Well System

For excavations in soils with low permeability, such as silt, silty sand, and clay, eductor systems are ideal. Eductor systems, also known as ejector systems, are specifically engineered to stabilize pore pressure and lower groundwater levels in deep excavations. They operate using the Venturi principle, by circulating high-pressure water through wells as deep as 50 feet. The speed and flow of the water creates a vacuum, which pulls groundwater through the riser pipe and out of the surrounding soil. 

Eductor dewatering systems are most commonly used to stabilize the side slopes and soil in an excavation area. With this method, you can lower the water table by more than 100 feet from the top of the excavation area. You can also operate more than one pump in a single station, for easier, more efficient dewatering operations.

Open Sump Pumping

Open sump pumping is the most cost-effective and least complex dewatering method. It is perfect for removing water in shallow excavations that contain permeable soil with high levels of sand or gravel. A sump is defined as a depression or hole lower than the surrounding area where water is allowed to collect. When the water reaches a certain height, the pump activates and pumps the water away from the site. 

This method is most effective when used to remove surface water and shallow groundwater. Since water collects on the surface and is then directed to the hole, there is no active removal of water from the surrounding soil, so it is not ideal for digging foundations or other excavations where soil stability is a concern. Typically, sump pumps are used to keep basements and low-lying areas free of standing water. 

Dewatering Systems at Triflo

At Triflo, we pride ourselves on creating superior quality dewatering systems for our customers in the mining, construction, utilities, and other critical excavation industries. Whether you require a standard well point system for utility excavation or a deep well point system for a commercial building foundation, Triflo has the knowledge and expertise necessary to help you choose the right system for your needs. 

With more than 40 years in the industry, we know that every project has different needs. That’s why Triflo’s extensive selection of dewatering systems can be tailored to meet the particular volume, depth, hydrologic conditions, and soil type of your application. Every system is specifically engineered for dependability and long service life in even the most extreme working conditions. 

Our extensive selection of custom manufacturing services includes 3D design, product engineering, and custom manufacturing. We also manufacture a variety of solids control equipment, as well as several patented environmentally friendly waste recycling and disposal systems. 

To learn more about our comprehensive selection of dewatering systems, visit our product page, or contact our experts today.

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