Leveraging Envision to Enhance Resiliency & Compliance with Ocean Outfall Legislation in SE Florida


  • Evan Bowles PE, ENV SP, Enrique Vadiveloo, Marta Alonso - Hazen and Sawyer
  • Evelio Agustin – CH2M

The Envision categories used to conduct a triple bottom line evaluation for this $5 billion project.

The first tier of analysis compared construction of a new WWTP vs no new WWTP.

The second tier of analysis determined the best configuration of the new collection and treatment systems.

We have also applied the Envision framework to analyze project alternatives in Nashville and New York City.

Wastewater facilities serve a fundamental role in promoting sustainable practices through abatement of water pollution and spread of disease. Often, wastewater infrastructure and its long-term operation & maintenance employs unsustainable practices in order to achieve these end goals. In an effort to promote a new sustainable paradigm for building construction, USGBC developed the LEED rating system in 2000. Given its specificity towards inhabited structures (e.g. offices), significant difficulty has been experienced in attempting to apply LEED’s structure toward water infrastructure projects. In order to bridge this gap, the Institute for Sustainable Infrastructure developed the Envision Sustainable Infrastructure Rating System in 2012. Envision provides a highly applicable framework for project teams that desire to implement a “triple bottom line” approach to utility planning, design, construction, and operation. Although the rating system can be utilized to retroactively assess and recognize a project with an award, it is ideally suited to provide a project team with a sustainability “standard of practice” to guide a project from cradle to grave.

In 2008, the Florida Legislature and Governor signed a law called the “Ocean Outfall Legislation”, which requires all wastewater utilities in southeast Florida utilizing ocean outfalls for disposal of treated wastewater effluent to significantly reduce nutrient discharges by 2018, and cease the use of ocean outfalls and reuse of 60% of that volume by 2025. Although these requirements would require a significant restructuring of any wastewater conveyance system, the Miami-Dade Water and Sewer Department (MDWASD) embraced it as a planning opportunity to address current and future resiliency challenges associated with climate change and extreme weather conditions. The metro Miami-Dade area is highly susceptible to storm surge and sea level rise, so planning central to those impacts were considered in how to make a mutual investment in resiliency while meeting the new law within schedule.

In 2013, the MDWASD completed a compliance plan that served to identify a number of strategies capable of meeting these goals, and identified a recommendation they believed would work best for them. A consultant team was selected to provide a validation report, which served to vet the costs, strategies, and schedules identified by MDWASD in their compliance plan. The consulting team conducted a thorough analysis of the existing and recommended conveyance and treatment systems, as well as the net present costs of capital and operations & maintenance. Given the scope of the system and proposed improvements, identification of the wide spectrum of non-economic drivers proved challenging. After evaluation of different externality evaluation techniques/tools, the consulting team elected to use the Envision system for comparative evaluation of the strategies identified in MDWASD’s compliance plan. This evaluation was completed in 2015, and was included in the consulting team’s validation report later that year.

This presentation will briefly describe the Ocean Outfall Legislation, its impact on the MDWASD wastewater conveyance and treatment system, and how the project team practically leveraged the Envision system to conduct a triple bottom line evaluation for this $5 billion project.

For more information, please contact the author at ebowles@hazenandsawyer.com.

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Horizons Fall 2017 (pdf)

Horizons showcases significant water, wastewater, reuse, and stormwater projects and innovations that help our clients to achieve their goals, and can help you achieve yours. Articles are written by top engineers and process group leaders, demonstrating and explaining the beneficial application of a variety of technologies and tools.

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