Storm Water Detention Pond Rehabilitation

At Joint Base Lewis McChord, the Flora Pond project stands as a sophisticated stormwater management system, featuring a 1.5-million-gallon detention pond equipped with advanced filtration technology. The facility’s innovative design includes a coalescing filter chamber and pre-settling detention cell, utilizing a high-water weir discharge system. This engineering marvel captures and processes millions of gallons of stormwater from JBLM’s Main Base, conveyed through 60-inch diameter pipes that run beneath Interstate 5 to North Fort.

The comprehensive project scope began with critical safety measures, including logging and removal of hazard trees near previously excavated contaminated soils from the storm detention settlement area. The team executed extensive dewatering operations, contaminated soil removal, and thorough maintenance of the existing facility – including dry pond cleaning, mowing, and aerating. The work extended to liner cleaning, replacement of coalescing filter chamber components, and installation of a state-of-the-art photo eye water discharge and measuring system, complete with operator training. Additional improvements on JBLM’s Main Base included installing a new catch basin, modifying street profiles, and constructing new curb, gutter, and paving systems.

Environmental stewardship took center stage throughout the project, requiring meticulous monitoring and management to prevent adverse impacts. The team faced unique challenges when accelerating the pre-settling basin schedule and working in the discharge stream alignment. These areas demanded manual labor exclusively, as contract requirements prohibited mechanical equipment in the heavily overgrown outfall zones.

Tunista Construction demonstrated exceptional project coordination, working in close collaboration with the prime contractor, United States Army Corps of Engineers, Department of Ecology, and Pierce County Health Department. This coordinated effort ensured all project management, execution, and training requirements were met or exceeded.

The Flora Pond project showcases Tunista Construction’s expertise in managing environmentally sensitive projects while successfully handling contaminated soils and implementing complex water filtration and discharge systems. This project stands as a testament to the company’s commitment to environmental stewardship and technical excellence in stormwater management infrastructure.