Pacific Foundation | Geotechnical Excellence

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Building the future

Sand Island Waste Water Treatment Plant

The Project

The Sand Island WWTP in Honolulu, Hawaii, is the largest facility of its kind in the state, serving the metropolitan area since 1978. This project will support a larger effort to modernize the plant, increasing its capacity to 90 mgd and implementing chemically enhanced primary treatment.

The Solution

A value-engineered bottom seal was created and installed with large-scale tooling and cement mixing using our Bauer BG33 and BG40 drill rigs. 

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The Result

The excavation yeilded remarkably dry and stable ground conditions at depths of more than 20 feet below the water table. 

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The primary objective of the Sand Island Wastewater Treatment Plant Cement Mixed Bottom Seal Project was to engineer and deliver a reliable and impermeable bottom seal for the treatment plant. By implementing this innovative solution, we aim to achieve the following:

Prevent Water Contamination

By constructing a robust bottom seal, we ensure that treated wastewater remains isolated from the surrounding environment, preventing any contamination risks and safeguarding the ecological balance.

Improve Treatment Efficiency

The cement mixed bottom seal acts as a barrier, effectively containing the treated wastewater within the designated treatment area. This optimization enables the plant to operate more efficiently and handle higher volumes of wastewater, contributing to a smoother treatment process.

Enhance Durability and Longevity

Through meticulous engineering and the use of high-quality materials, our project aims to provide a long-lasting solution. The cement mixed bottom seal will exhibit excellent durability, reducing the need for frequent repairs or maintenance, and offering a sustainable solution for years to come.

Minimize Environmental Impact

Pacific Foundation is committed to environmentally responsible practices. With the Sand Island Wastewater Treatment Plant Cement Mixed Bottom Seal Project, we prioritize minimizing the project’s ecological footprint. Our methods prioritize sustainability and ensure that the natural habitat and local wildlife are not adversely affected.

Unique Challenges

A Solid Partnership Delivers an First-of-its-Kind Solution

The Sand Island Cement Mixing Project stands as a testament to Pacific Foundation’s unwavering commitment to pushing the boundaries of engineering excellence. This case study showcases our groundbreaking achievement in implementing a value-engineered bottom seal, a first-of-its-kind innovation in the industry. With ground conditions presenting immense challenges at depths exceeding 20 feet, our team’s ingenuity and expertise were put to the test. Through meticulous planning and advanced techniques, we successfully overcame these obstacles, delivering exceptional results and setting new standards in the field. Discover the remarkable story behind this pioneering project and witness how Pacific Foundation’s innovative solutions can turn the most challenging situations into triumphs.

Challenging Local Ground Conditions

To ensure accurate soil analysis and determine optimal cement mixing methods, our team conducted thorough geotechnical investigations. These investigations revealed a complex and challenging ground composition at the Sand Island site. Notably, we encountered multiple layers of sandstone at depths of 20, 21, and 25 feet, further adding to the intricacy of the project. Additionally, a coral layer was discovered at a depth of 9 feet, presenting a unique geological feature that required careful consideration and innovative approaches. These varied ground conditions necessitated meticulous planning and engineering expertise to develop a value-engineered bottom seal solution that could withstand the demanding environment.

Quality Control

To ensure the correct and thorough cement mixed bottom seal for the Sand Island project, our team implemented a comprehensive and meticulous test program. One notable aspect of this program involved sending a sample box down to the bottom of the treated site. By retrieving samples at various depths, we were able to conduct thorough evaluations and analyses.

Coordination and Scheduling

Managing a complex project like the Sand Island WWTP project necessitates efficient coordination and scheduling. Our project team and engineers meticulously planned each phase with the client, and adapting to the challenges we faced  on site. We maintained open lines of communication with all stakeholders, facilitating seamless coordination among contractors, engineers, and suppliers. By closely monitoring progress and addressing any bottlenecks promptly, we ensured the project stayed on track and completed within the designated timeframe.

By proactively addressing these challenges, Pacific Foundation demonstrated its ability to deliver outstanding results while maintaining the highest standards of quality, environmental responsibility, and project management. The Sand Island WWTP project stands as a testament to our unwavering commitment to excellence and innovation in the field of wastewater treatment.

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