Dewatering on Construction Sites

Many construction sites have to worry about surface and groundwater, which can be hazardous for workers and damaging to equipment. Removing the water from your job site is often necessary, which can be done through dewatering. This process is typically one of the first steps in preparing a construction site for work.

You can use many different dewatering methods to remove water from a specific location, including sump pumps, wellpoints, eductor wells and deep wells. The method you choose will depend on various factors and the type of water you need to remove. Learn more about the dewatering process, the four different methods, the benefits and the equipment you may need to complete the process.

Jump to a section:

• What Is Dewatering on a Construction Project Site?
• What Are the Four Methods of Dewatering?
• Factors to Consider When Choosing a Dewatering Method
• Requirements for Dewatering
• Benefits of Dewatering on Construction Sites
• Why You Should Rent Equipment for Dewatering Projects
• Equipment Available for Dewatering Construction Sites

What Are the Four Methods of Dewatering?

Four primary construction dewatering methods help improve the efficiency and safety of work sites. Different approaches work better for specific soil and excavation types, so understanding their differences is essential to knowing which method will work best for your construction project.

1. Sump Pumps

Sump pumps are a cost-effective and simple method for removing water from a construction site. This method uses sumps, or pits, dug to a specified draining area where water is collected. Then solid-handling pumps move the water from the pit to a discharge pump.

Sump pumps are ideal for construction sites with minimal surface water, shallow excavations and low-permeable soils. However, sump pumps can sometimes increase the risk of collapse or erosion. They can also produce more water when working with high-suspended solids.

2. Wellpoints

Wellpoint systems use small individualized wellpoints placed around different parts of an excavation that connect to a centrifugal header pipe equipped with a vacuum. Wellpoint systems are ideal for low groundwater levels to create a dry and stable site for construction projects.

Like sump pumps, wellpoints work best on construction sites with low-permeable, fine-grained soil and shallow excavations. However, they can also be used with high-permeable soils. Wellpoints are easy to install and cost-effective, making them viable for many construction projects.

3. Deep Wells

Deep well systems use drilled wells that all have submersible pumps. These systems help lower groundwater. Deep wells use gravity-based methods and are broader and deeper than wellpoints. This dewatering system typically removes water from previous structures underneath the existing excavation.

Deep well systems are ideal for work sites with large amounts of water. This method works well with multiple excavation depths and high-permeable soil. However, deep wells are an extensive system and aren't as cost-effective as other options.

4. Eductor Wells

Eductor wells use a pumping station comprised of small wells. These wells use nozzles to make a vacuum, which helps draw groundwater through a valve and piping system.

Once installed, eductor wells are low maintenance and cost-effective. These wells can also reach significant depths compared to sump pumps and wellpoints. Suction lifts don't limit educator wells, so this method is ideal for deep excavations. You can use this method when vacuuming or closed well-spacing is necessary or working with low-permeable soil. However, this method isn't practical when working with high water volumes.

Factors to Consider When Choosing a Dewatering Method

Different factors will influence the best dewatering method for your construction site. Some of the most critical factors to consider are budget, soil, excavation depth and water volume.

1. Budget

Cost can sometimes affect what dewatering method you choose. Some methods are more cost-effective than others, such as sump pumping or wellpoints. These methods can work for many construction projects but may not be suitable for all. If your project requires deep well dewatering, one of the more expensive methods, it's better to use this method than a more affordable approach that won't adequately dewater your job site.

2. Soil

Soil type plays a significant role in what kind of dewatering method you choose. Soil permeability, or how water flows through the soil, is one of the most important factors when deciding which dewatering method to use at your construction site. Eductor wells or sump pumping only work well with low-permeable soils. Other methods, such as wellpoints, work well for high or low permeability.

3. Excavation Depth

The depth of your excavation helps determine your dewatering method. If you have deep excavations, eductor wells or deep wells would be best. Shallow or small excavations are better suited to sump pumps or wellpoints. However, eductor wells aren't suited to deep excavations with high water levels.

4. Water Volume and Type

The water volume, or how much water is present, and whether it's groundwater or surface water affect which dewatering method you can choose. Eductor and sump pumps work best when there's not a lot of water to remove from the construction site. Wellpoints work when shallow aquifers reach only 50 feet or less. Deep wells are the only method that can handle high volumes of water.

Requirements for Dewatering

You may need a dewatering permit, especially when the water is discharged into a public drain and isn't treated before being moved to local water sources. The permit requirements vary based on the rules and regulations in your area or jurisdiction. Most permits require you to provide drawings and engineering to show how the water is treated.

These plans help construction teams and engineers understand the conditions at the site and determine the best method for capturing water. Your local officials need to approve your plans before you can get a permit. You may need multiple plans, and all options must be approved.

If you cannot distribute the water you've collected onsite, you'll have to divert the water to sanitary or stormwater sewer lines. In these instances, more testing and filtering are necessary before releasing water into public water sources. All contractors are responsible for redistributing and treating removed water correctly, and inspectors will check the water quality.

Water Removal Options

Once you've removed water from your job site, it has to go somewhere. You can do a few different things with the water once it's been displaced from your construction site, depending on your budget, project site specifications, water turbidity and state or federal laws. Water removal options include the following:

• Detention ponds or basins: This option comprises manufactured bodies of water to store runoff. You may be able to use these locations to relocate removed water, which can help reduce the transfer of contaminants and pollutants to other bodies of water. If you decide to use detention ponds or basins, check in with state and federal regulations and requirements for monitoring these ponds or basins.
• Boxes or tanks: Another option is storing the water you've removed in boxes or tanks, allowing you to transport them from your construction site to another location easily. You can also use boxes or tanks to filter solids, drainage, sludge or sediments. Like detention ponds and basins, you'll also need to check in with state and federal regulations about the water you want to move and where.
• Release or redistribution: Release and redistribution allow you to return the water you've removed from the construction site to wetlands, rivers and lakes. The water you've removed from your construction site must be treated or filtered before you release it into the waterways, and you'll need permission from local or federal authorities.

Benefits of Dewatering on Construction Sites

Dewatering construction sites has many benefits for construction companies, including the following:

• Improving worker safety: Dewatering construction sites helps make the work site safer by reducing the risk of mud forming, which can lead to dangerous falls. Dewatering these sites can also remove contaminated water that can cause health risks.
• Prevents delays: Water on the job site can result in equipment failures, flooding and more problems that cause project delays. Dewatering can help avoid these delays, saving on costs and helping your complete projects on schedule.
• Ensures stable work areas and stable soil: Water buildup on construction sites can turn into unstable foundations, mudslides and bogging, which can cause equipment to fail and create dangerous, unstable work conditions. Dewatering can keep your job site and soil stable, helping maintain the quality of your work and improving overall safety.
• Improves longevity of work equipment: Dewatering removes excess moisture from your work site that can damage your equipment, causing rust and electrical failures.
• Reduces environmental impact: Dewatering methods can minimize environmental impact by preventing soil corrosion and removing contaminated water. Dewatering can also remove other site hazards from the work area.

Why You Should Rent Equipment for Dewatering Projects

Renting equipment has many benefits over buying new or used. Some of the benefits of renting equipment include the following:

• Reduces costs: Renting reduces your overall costs since rental equipment is more affordable than brand-new equipment. You can also save on transportation and storage costs since the rental company can deliver the equipment right to your work site. You won't have to worry about paying for maintenance or repair costs since the rental company covers this.
• Reduces responsibilities: Maintenance and repairs are a big part of owning equipment. When you rent instead of buying, the rental company is responsible for the maintenance and repairs, reducing your responsibilities and allowing you to complete your work without worrying about keeping up with your equipment.
• Improves flexibility: If you're working on multiple projects at once, sharing equipment between job sites may not be possible. Renting allows you to be flexible enough to meet the demand for your projects. Every job is different, and you can choose from various rental equipment to suit your needs. Renting equipment can fill gaps in your fleet on short notice, enabling you to move forward with projects quickly and giving you a competitive advantage over other contractors.
• Minimizes fleet: As your business evolves, you'll need to find more equipment to meet demand and offer specialized services to your clients. Owning an extensive equipment fleet requires more time managing your equipment, including maintenance, repairs and storage. Renting allows you to grow your business without worrying about financing and managing new or used equipment. Renting also ensures you can take more opportunities without expanding your fleet.
• Gains access to more options: Rental equipment is available in various models, allowing you to find exactly what you need. You may be unable to find the right fit from new equipment since you're limited to brand-new models. With new machines, your workers may need more training. Renting gives you access to a broader range of equipment, which can help you find the exact machine you need to complete your projects efficiently.
• Improves cash flow: When managing your equipment, you must budget for unexpected repairs, maintenance, storage and operator training. Renting allows you to eliminate these operating expenses since the rental company is responsible for most of these costs. Access to more cash flow means you can take on more projects and allocate your resources to other aspects of your business.
• Allows you to try before you buy: You may be interested in buying but aren't sure what you want or need for your projects. Renting enables you to try before you buy, helping you determine if specific equipment would be a good investment for your business. You can test how equipment performs and if your operators like it before committing to a purchase, which can help reduce the risk of new equipment going to waste.

Equipment Available for Dewatering Construction Sites From The Cat® Rental Store

If you're looking for equipment for dewatering at a construction site, The Cat® Rental Store has several options. We offer two main types of equipment for dewatering processes — pumping and water equipment.

1. Pumping Equipment

Pumping equipment removes water from your work site and helps move it to another location, improving the safety of your workspace and keeping projects on schedule. The Cat Rental Store offers a wide range of pumping equipment, including the following:

• Portable pumps: Portable pumps are highly mobile, making it easy to move them from one place on your job site to the next. These pumps are more convenient at sites where multiple locations need water removal. Portable pumps are more flexible than other pumps since you can take them anywhere on your work site.
• Submersible pumps: This type of pump goes into the water, making it an efficient way to remove groundwater from the job site. Submersible pumps reduce the energy required to move water to the pump, which can help save energy and improve the pump's life span. Our submersible pumps can be used to dewater various work sites, including mines and deep-well drilling projects.
• Towable pumps: Towable pumps allow you to move them to different locations at your job site by towing them with a vehicle or other equipment. These pumps are larger than portable pumps, which can help you remove more water efficiently, but are still moveable, allowing you to remove water from multiple areas.

Renting a pump from us allows you to access a wide range of pumping equipment that you can trust is well-maintained and can serve your project needs. We can deliver your chosen pump to your work site, even with short notice, helping you quickly move on with your project.

2. Water Equipment

The Cat Rental Store also offers water equipment to help you move water from your job site to another location after it's been pumped. We offer two primary types of water equipment, including the following:

Find Dewatering Equipment at The Cat Rental Store

If you need dewatering equipment to improve the safety and efficiency of your work site, The Cat Rental Store can help. We have a wide range of dewatering equipment, from various types of pumps to water transportation trailers and trucks. When you rent from us, you won't have to worry about maintenance, repairs or general upkeep. We also offer flexible rental terms to ensure you have your equipment only as long as needed, helping you save on overall costs.

You'll also have onsite support and technical assistance to help you through every step of the rental process. Browse our selection of equipment today, contact us for a quote or find a dealer near you to speak to a representative in person or to look at the equipment before you rent.