Project Location: Denver, CO

Owner: Confidential

GC: Saunders Construction

Project Revenue:  $372,000.00

Project Timeline: August 2016 – February 2017

The Challenge:

The excavation for the deep foundation extended through sand and gravel alluvium near Cherry Creek and into claystone bedrock in the deepest sections. Specialized drilling equipment is required when dewatering excavations near an impermeable material such as bedrock. Due to the proximity to Cherry Creek, high flow rates were anticipated.

The water quality at the site required treatment for high levels of Iron, Manganese, Arsenic and several other constituents. Griffin’s treatment system would need to treat the water to the discharge standards set in the discharge permit for this project.

The Solution:

Griffin designed, installed and operated turn-key dewatering and water treatment systems for Saunders Construction. Griffin drilled and installed a perimeter deep well dewatering system consisting of 12 wells drilled to 50 ft. Once the subgrade excavation was completed, Griffin installed a wellpoint dewatering system within the shoring to complete the deeper elevator core excavation. The wellpoint system supplemented the deep well system to improve the dewatering performance near the bedrock interface.

Griffin designed and installed a 500 gallons per minute (GPM) temporary treatment system to treat for a variety of constituents and varying influent water quality. High levels of Iron, Manganese, and Arsenic required treatment. Griffin designed a treatment system that incorporated chemical injection, settlement/separation, and pressure media vessels. The water was successfully treated for the duration of the project and the system was removed once the building was constructed to 2 stories above grade.

The Griffin Difference:

The combination of the deep wells and wellpoints and sumping allowed Saunders to complete the project successfully. All water from the three different pump sources was conveyed to the onsite treatment system.

Griffin provided turn-key solutions for the challenging dewatering and water treatment requirements for this project. By working closely with Saunders throughout the dewatering and treatment installation we ensured seamless operation of both systems. Griffin provided 24/7 operation and maintenance of the dewatering and treatment system for the duration of the project.