Why Conduct a Pumping Test?

Understanding your site’s conditions is essential to mitigate risks for basement or excavation projects. By identifying potential issues early, you can reduce the risk of unforeseen expenses and delays later on. Pumping tests are used to validate and optimise the dewatering strategy. Understanding discharge flow and water quality early on can also be key for getting discharge consents in place and budgeting for discharge fees.

Key Questions to Address Before Designing a Dewatering System:

• What are the site geometries, including excavation levels, localised pits, proposed shoring types, and toe levels?
• What is the natural standing groundwater table relative to the excavation and what level does the water need to be drawn down to?
• Any specific project programme or site constraints to be considered?
• How close is the site to open water sources, such as the sea, and do water levels fluctuate?
• What is the site’s geology? Are there loose soils, fractured rocks, voids, or faults that might lead to unpredictable inflows?
• Is there existing site information available to better understand the permeability and nature of the ground, such as photographs and logging of cores, sieve analysis, site permeability tests, and local experience?
• Where will the water be discharged during the works and are there any specific requirements to be met such as water quality and flow limitations? Will treatment of discharged water be required?
• How will the ground react to being dewatered and what is the best method for achieving the drawdown?

By answering these questions, you can start to build up an effective dewatering approach. A well-conducted pumping test can be used to test hypothesis, validate designs and provide added confidence.

Our Approach at WJ Saudi:

The primary pumping test method we use in Saudi involves extracting water from a single deepwell while monitoring changes in water levels in monitoring wells installed at set distances from the pumped well. This drawdown data is used for calibrating 2D/3D computer models and optimizing dewatering solutions. WJ offer a wide range of pumping test and recharge test options. We work closely with clients and consultants to choose the best pumping test approach for their project needs.

The Benefits:

• Cost Efficiency: Effective dewatering is often more economical and less disruptive than alternative methods such as grout plugs, freezing, or extensive shoring.
• Project Confidence: A well-designed and performed pumping test validates your dewatering strategy, ensuring it’s the right fit.

Curious about how pumping tests can enhance your project? Connect with us to find out more