This member of your construction team gets no lunch breaks or sick days. Choosing the right solution for this 24/7 worker is critical.
It’s been around for more than a century, and the wellpoint process for predrainage is still going strong. This system is cost effective, and it’s optimal for water-bearing soils such as sand and gravel.
Excavation and foundation work can’t get underway unless the ground is dry and stable. Wellpoints take care of this. The method can also keep the ground dry during heavy rain events and flooding conditions. Once wellpoint dewatering starts, it has to stay in continuous operation until the construction project is completed. Therefore, the pumps you use have to be up to the challenge. For this process, our customers request the Rotoflo™ for their wellpoint dewatering needs.
Scalable and cost-effective
There are two basic components in this dewatering system:
1. The wellpoints themselves. These are small diameter wells connected to a header pipe. (They’re usually vertical, but for long trenches, horizontal wellpoints can be installed with trenching machines.)
2. A shared wellpoint pump and associated header piping. The pump creates a vacuum in the header pipe drawing water up out of the ground.
Associated header mains, water discharge pipes, and power supply generators complete the setup. Depending on the size and scope of the project, you might also work with electrical controls and monitoring systems.
The simplicity of the system makes it possible to scale dewatering to just about any level necessary for the construction project. Wellpoint systems can be expanded to thousands of wellpoints that use multiple pumping stations. The method is well suited when close spacing is required.
There are few drawbacks. The biggest challenge is that this is a vacuum-type system. Its effectiveness is limited by depth and available suction lift. In practice, wellpoints are best suited for shallow excavations in stratified soils. It’s often the method of choice for pipeline trench excavations.
Best practices
Wellpoints are typically installed in lines or rings around the excavation. Diesel or electrically powered pumps remove water to lower the groundwater level. Any project where the groundwater level is close to the surface is a good application for wellpoints.
This dewatering system is an effective way to keep water out of a construction site. It requires minimal maintenance once installed and operating. It’s more expensive than trash pumps, which are a better choice for short-term projects. But, the wellpoint method is a solid choice for projects with longer durations.
The pump makes the project
The water pump you choose for this system can be its point of success or failure. It will have an ongoing job to keep groundwater from re-entering excavations at your construction site by lowering its level.
Keep these important requirements in mind when making a selection:
- Wellpoint dewatering pumps must be able to handle intermittent water flow and large amounts of air. They’ll move most of the water at the start, but then change to a maintenance mode to maintain the lowered groundwater level. Look for a self-priming, valve-less positive displacement pump. They’re best for the constantly changing levels of water and air.
- Water conditions and consistencies can change. Make sure the pump will handle this. It should be able to pump slurries and brackish waters.
- The wellpoint system must operate continuously until the construction project is completed. You must be confident that your vendor has recommended a pump known for its dependability.
- The pumps must be fuel-efficient because they’ll be running 24/7.
Construction site noise can be a concern if you’re in a residential area. Look for a pump that features noise abating enclosures.
- If you’re unfamiliar with the pump, ask your vendor for assurance that it’s easy to maintain. Scarce parts, or difficult maintenance accessibility can cause big problems. If you don’t plan to maintain it yourself, it’s crucial to make sure the company renting it to you has a track record of fast, dependable service.
Your Dependable Partner on the Site
The right pump for the right job keeps you on top of construction completion schedules. Wellpoint dewatering is going to be there from start to finish. If the pump you rent puts a check mark next to all of these pump characteristics, you’ll have a steady, dependable partner on the job. Feel free to contact us regarding your dewatering needs.
