Twin Creeks Force Main
Expansion in the northern area of St. Johns County, Florida, one of the largest growing counties in the U.S., has placed increased demands on the region’s water and sewer systems, requiring the construction of a large force main from CR 210 to Russell Sampson Road to transport sewage to a nearby wastewater treatment plant. RS&H provided the project management, design, permitting, survey and geotechnical information arrangement and evaluation, and construction management and inspection services for the installation of the new force main. RS&H also provided the Global Positioning System (GPS) data collection management, as well as processing for the GPS maps and as-built plans.
The project required the installation of over 12,600 linear feet of 24-inch diameter force main piping, beginning at a large triplex pump station within the treatment plant. The project also required a complex tie-in design, which considered plans for the future expansion of CR 210, as well as the entrances and cross drains for a planned subdivision in the area, as the route passed through a wooded, unpopulated area soon be filled with new housing units. All of these factors required coordination with various groups, including St. Johns County, the plant operations and maintenance group, developers, and the regulatory authorities.
The design called for the use of the Horizontal Directional Drill (HDD) method of construction for the force main’s crossing I-95, which was approved by the Florida Department of Transportation for 600 linear feet of 30-inch diameter high-density polyethylene pipe. Particular care was given to the design of the pipe, drill, and clearance from the roadway. This project was completed on a fast-tracked schedule and within its budget for engineering, project management, and construction management.