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Written by Kelly Sanchez on October 29, 2025
Any further work on the revolutionary technology to turn wastewater sludge into salable fuel to power cruise ships is contingent on whether federal funding is announced for the project on Oct. 31, according to the Miami-Dade Water and Sewer Department.
If the federal grant is approved, county commissioners will receive credit for in-kind expenses.
That includes cutting the cost of a small-scale test from $3 million apiece to $1.5 million apiece for the county and proposers. The $1.5 million from the county would be returned if a successful test in two years moves the hydrothermal biosolids technology ahead to a far larger processing plant that would cost the county nothing and handle a third of its wastewater sludge.
The sludge-to-fuel technology is proposed by nonprofit Provident Resources Group plus four for-profit partners that are seeking both the U.S. Department of Energy grant and the test urban wastewater plant located at Miami-Dade’s Central Plant on Virginia Key.
Documents from Provident Resources say the process can convert 37% to 59% of liquid sludge to marine fuel. The company’s proposal indicates Port Miami’s vessels as users of the product.
The county accumulates 700 million wet tons of biosolids sludge per day, costing $26 million a year to send to a disposal site for composting, land application and landfilling. With those costs rapidly rising and fewer available disposal sites, the potential breakthrough might offer an alternative for biosolid management and renewable fuel production.