Project Summary

Earthtech became involved in the project when unexpected groundwater conditions and piping in the excavation floor were encountered during construction of 7.8m to 9.1m deep excavations and shafts for wastewater infrastructure construction. We carried out groundwater investigations and pump testing to define a dewatering solution that provided a dry, safe and stable excavation during the 6-month construction dewatering period. Earthtech's involvement continued during construction, with the management of pumping rates and monitoring to ensure that neighbouring properties and infrastructure were protected from dewatering effects.

Services Provided

• Groundwater investigations and pump testing.
• Groundwater analysis and design of a bore-field dewatering system.
• Preparation of Assessment of Environmental Effects and consenting of the groundwater take (dewatering) and diversion activities.
• Preparation of Groundwater and Settlement Monitoring and Contingency Plan.
• Ongoing involvement and contractor support during dewatering and construction activities, including assisting with the setup of groundwater level alert and alarm notifications and consent compliance.

Project Conclusion

This project demonstrates how Earthtech can respond rapidly during construction and provide a practical dewatering solution which was effective and flexible in providing safe and stable excavations.