Islamorada (FL) Wastewater Treatment, Pumping and Conveyance Systems

ARCADIS-U.S., Inc. Design-Build-Operate Project

In an effort to prevent unpermitted and noncompliant wastewater effluent from entering the pristine coastal waters surrounding Florida communities, State legislators passed a law in 2010 requiring that by December 2015, all wastewater generated in communities must be collected and conveyed to a central location for treatment and disposal. This required the Village of Islamorada (located in the Florida Keys, 100 miles south of Miami) to address the serious problem presented by failed septic tanks, which were causing septic leachate to percolate through porous coral rock into both the Gulf of Mexico and the Atlantic Ocean

In 2012, the Village selected the design-build team of Layne Construction and ARCADIS-US to design, build and operate a hybrid collection system (combination vacuum collection & low-pressure sewer) on four Florida Keys, serving the combined population of 20,000 and connecting 75 existing package-plant facilities within the Village.  In this new system, the collected wastewater will be conveyed via a 26-mile conveyance-force main through an extremely congested corridor along US 1/Overseas Highway, through the Village and Key Largo to the 1.4 MGD Key Largo Water Treatment District’s Regional Treatment Plant. The $100 million project is expected to be completed in 2015.

The Village selected the design-build delivery method to address the extreme schedule demands and requirements needed to closely coordinate all aspects of the project concurrently. Routing and constructing the force main through the corridor is made difficult by busy traffic conditions and pending Florida DOT paving projects on US 1, numerous utilities in the US 1 right-of-way, environmental concerns with protected trees and wetlands, and requirements for constructing more than 9,000 linear feet below the highly-protected channels between keys. This project will ultimately improve the quality of the waters surrounding the Village of Islamorada.

To support the local economy, a local staff of eight individuals was hired to be be on-site at least through the end of construction in the fall of 2015.  The DBO team is also under contract to operate the system for 30 years, which will create operator jobs.  Layne subcontracted this work to Severn-Trent.