Pasco County Facility Harnesses Solar Power in Trailblazing Biosolids Process



Processes about 23,000 wet tons

per year


Harnessed solar energy in a unique biosolids recycling process that produces Class AA fertilizer—additionally, this process reduces energy costs, limits the carbon footprint, and avoids biosolids disposal in landfills


Inspired similar site designs and unique biosolids recycling process developments around the United States


Collaborated with Merrell Bros., Inc., Pasco County Utilities, and the Florida Department of Environmental Protection to design a facility that complies with Florida regulations and meets community needs

Communities across the nation have been wrestling with how to dispose of biosolids in a way that prevents pollution and waste from being discarded into quickly growing landfills. In response to this widespread problem and updated Florida biosolids disposal regulations, Kimley-Horn partnered with Merrell Bros., Inc. on a design-build-operate project that provides a sustainable solution to this wastewater concern.

A Unique Biosolids Recycling Process

Kimley-Horn collaborated with Merrell Bros., Inc., the Florida Department of Environmental Protection, and Pasco County Utilities to gain approval for this innovative biosolids recycling plan. Patented by Merrell Bros., the recycling process uses solar power, carefully adapted air circulation and storage, volume reduction, and limited fossil fuel pasteurization to convert biosolids material into Class AA FloridaGreen fertilizer rather than disposing of it.

Kimley-Horn worked closely with Merrell Bros. to plan and design the biosolids-to-fertilizer conversion campus. We also coordinated with other stakeholders to meet county regulations and design the site for each step of the recycling process, providing the following services for this innovative project:

The Finished Sustainable Site

The completed 3-acre site includes multiple greenhouses with large fans, a massive conveyor belt system, and a loading dock that supports the reception of biosolids material. The unique biosolids process has much lower energy costs than other disposal methods, and using solar energy for the drying stage minimizes the carbon footprint and promotes sustainable product development. As the demand for Class AA FloridaGreen fertilizer and the need for updated biosolids disposal grows, Kimley-Horn and Merrell Bros.’ site design is expected to expand across the nation, impacting more communities with this sustainable method.

Quick Facts


Merrell Bros., Inc.


Pasco County, FL


"Every community that has central water and sewer has to deal with this disposal issue, and this project provides a green, sustainable way to create a useful product. It is very innovative to be able to solve this problem that almost every community has across the country."

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