Protecting the Magic City

The Magic City…. Miami, Florida.… images of palm trees, azure waters and sugar-sand beaches. Behind the glamorous persona of Miami lies a city of 2.5 million people and all of the infrastructure needs of any major metropolitan community. Underground lies a complex network of utilities serving the tourists, residents, and the Miami business community on a daily basis. Principal among these is a system of 3,042 miles (4,896 km) of gravity sewer pipe, 1,039 pump stations, and 908 miles (1,461 km) of force main sewers that the Miami-Dade Water and Sewer Department (MDWASD) relies upon to serve the needs of the community while preserving the elegance and beauty of the Magic City. On June 18, 2010, MDWASD experienced a sudden and catastrophic failure of a 72" (1829 mm) force main that had been installed in 1978 resulting in a spill of 15,000,000 gallons (56,781,000 liters) of untreated sewage into the Biscayne Canal, an event that could have resulted in a devastating impact on local residents and the surrounding waterways of Miami. This paper will examine the nature of the pipeline failure and outline the steps taken by MDWASD to evaluate the condition of the existing force main and assess the options for repair, replacement or rehabilitation of the 72" (1829 mm) force main. The discussion then focuses on the timely and effective actions taken by MDWASD in addressing this situation to minimize disruption of service by slip-lining the deteriorated concrete pipe structure with 8000 linear feet (2438 m) of 63" (1600 mm) diameter high density polyethylene (PE) pipe. The paper will review the factors leading to the selection of this rehabilitation technology and conclude with MDWASD's outlook on the need to continually asses the integrity of underground assets and the options for repair, replacement or rehabilitation of its waste water infrastructure.