City of Fort Lauderdale, FL: 2021 Trenchless Project of the Year

location

City of Fort Lauderdale, FL

Installation Date

December 2019

owner

City of Fort Lauderdale

scope

Horizontal Directional Drilling
3,100 ft of 54-inch HDPE

situation

In December 2019, the City of Fort Lauderdale had numerous pipeline breaks to its seven-mile major sewer transmission. The breakage resulted in more than 200 million gallons of sewage spilling into nearby waterways. The City had to declare an emergency rehabilitation request and awarded two design-build contracts for Murphy Pipeline Contractors, an IPR company. The project was split into multiple phases to design, permit and construct the different sections concurrently. Most of the projects used trenchless technology and HDPE pipe, which provided a significant cost save for both material and installation costs. Within the seven-mile sewer main transmission, 85 percent of the pipeline was installed and replaced using HDD or horizontal directional drilling via 17 crossings through the heart of downtown Fort Lauderdale and adjacent residential areas.

Solution

“The installation of 3,400 ft of 48-in. HDPE DR (Dimension Ratio) 13.5 pipe.; the installation of 3,100 ft of 54-in. HDPE DR 17 pipe with 22 fusion welds during pipe pull back; four HDDs with tight-radius compound curves using 48-in. HDPE DR 13.5 pipe, which included a 2,600-ft and a 1,400-ft S-curve; and three major waterway crossings (Tarpon River, 1,800 ft, New River, 2,500 ft and Middle River, 1,600 ft), reaching depths of over 60 ft. Due to depth and soil conditions, a 48-in. DR 11 pipe was used in the Middle River crossing making this one of the first projects in the United States to use this pipe size and DR. Other sections installed via HDD ranged from 1,100 to 1,300 ft.” - Trenchless Technology Magazine, 2021.

In addition, the project team solved numerous technical challenges through the construction, such as four water crossings. Three of the four water crossings presented opportunities for ingenuity and three of the four were installed via trenchless technology. “One example is the Tarpon River crossing that was adjacent to a bridge with only 8 feet of available right-of-way for installation. A precise compound curve was utilized in the design to achieve the desired HDD alignment.”

Conclusion

By using trenchless technology, Murphy Pipeline Contractors were able to complete the project within 18 months. The 18 months included the HDPE installation, avoidance of utility conflicts, minimal traffic, and neighborhood disruption, and minimal restoration. In addition, the nature of the trenchless technology helped expedite regulatory agency approvals and permits from Federal, State, and County agencies including the United States Army Corps of Engineers, Florida Department of Environmental Protection, and the Florida Department of Transportation.

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