Original Post: Engineering News Record | October 23, 2019
Central Pasco County Beneficial Water Reuse Project
Land O’ Lakes, Fla.
Award of Merit
Owner: Pasco County Utilities
General Contractor: Phillips & Jordan Inc.
Lead Design Firm: Jacobs
Civil Engineer: Jacobs
Known as the 4G Wetlands, this first-of-its-kind 176-acre groundwater recharge wetlands system is constructed on upland pastures. It is designed to work in unison with an existing 500-million-gallon reclaimed water reservoir to balance wet-weather supply and dry-weather demands.
The design team’s main challenge was balancing wetland inflow with infiltration, precipitation and evaporation to maximize groundwater recharge without a wetland outflow. During project development, the team designed a new modeling method to forecast treatment through infiltration and assess water quality performance.
Because of the complex curvature of the wetlands, the contractor used GPS-guided grade-control equipment to match the design of the wetland cells. The use of grade control allowed the final construction elevations to be obtained within tenths of an inch.
The system can receive 5 million gallons of advanced secondary reclaimed water per day and passively recharge the surficial and Floridan aquifer systems while protecting water quality. It also provides new wildlife habitat and biological diversity within its 15 constructed wetland cells, each of which offers unique design features. The system addresses decade-long concerns regarding groundwater drawdowns in areas affected by public water supply well fields in southwest Florida. The public-private project’s life-cycle costs are estimated to be approximately half that of a conventional system’s.