Regional Biosolids

AdobeStock_69254574-scaled

Excess nutrients from land application of human waste from wastewater treatment effluent termed “biosolids”, reach surface waters as a result of rainfall runoff and continues to increase the occurrence of chronic harmful algal blooms (HABs). Today Florida’s central sewer wastewater treatment facilities produce approximately 340,000 dry tons of biosolids.  Approximately 100,000 dry tons of biosolids qualify as Class B biosolids which are treated sewage sludge meeting U.S. EPA guidelines for land application as fertilizer with restrictions and are allowed to have detectable levels of pathogens. Another 100,000 dry tons of biosolids are deposited in various landfills throughout the state. The final 140,000 dry tons of biosolids are further processed, dried, and composted with material from the landscape industry to produce approximately 200,000 tons of Class AA biosolids, which can then be distributed and marketed as fertilizer. This class of biosolid is completely unregulated and land-applied mainly on pasture and to a lesser extent citrus.  However, citrus fertilized with human biosolids seldom qualify for overseas export.

Bahia grass pastures in Florida can generally produce satisfactorily without total Phosphorous (TP) fertilization, and every crop in Florida can be grown economically without the use of biosolids as a fertilizer.  Biosolids provide an inefficient form of fertilization that provides only a fraction (less than 40%) of plant available nitrogen that can result in both total Nitrogen (TN) and TP over fertilization, which may negatively affect springs, rivers, lakes, estuaries, and other surface waters. Of additional concern are compounds found in human wastewater biosolids which may include hormones; steroids; bacteria; viruses; polychlorinated biphenyls (PCBs); pharmaceuticals; antibodies; polybrominated diphenyl ethers (PBDE fire retardants); polyfluoroalkyl substances (PFAS) like Teflon, polishes, waxes, paints, and household cleaning products; organics; metals; and artificial sweeteners.  Although these materials are applied in a manner that may not be harmful to humans according to EPA "guidelines,” their accumulated secondary impacts are not entirely known.

Both Class B biosolids and Class AA biosolid fertilizers contain approximately 5.5 % TN and 2.2% TP. Therefore, land application of 300,000 dry tons of Class AA and Class B biosolids deposits over 33 million pounds of TN and 13.2 million pounds of TP on agricultural lands each year.  Peer reviewed studies, such as those related to the Lake Okeechobee drainage basins, estimate that +/- 12% of both TN and TP imports will find their way to surface waters.  This basin currently receives over 1,000 dry tons of TP from Class AA biosolids which, could amount to 120 dry tons or 240,000 pounds of TP to surface waters.  Large areas within Florida such as the basins draining into Lake Okeechobee already exhibit enough legacy phosphorus to last for the next 25 to 60 years. While the practice of land-applying Class B biosolids was recently banned in the Lake Okeechobee, Caloosahatchee, St. Lucie River and Everglades watersheds, the St. Johns River Upper Basin in 2016 received nearly 74,000 tons of Class B biosolids, or approximately 74% of the Class B produced in Florida, in its watershed.

However, there are solutions to this problem. Agricultural crops can be grown profitably without land applying this inefficient nutrient source. There are alternative technologies that should be considered such as: pyrolysis; vapor recompression distillation; boiler technology electric generation; and supercritical water oxidation to improve recovery of resources and sustainable management of biosolids.

Council works with local and state governments to see that reduction and eventual elimination of the land application of human wastewater biosolids is a priority. Council supports the establishment of “Pilot Projects Programs” for funding new state of the art wastewater technologies to improve recovery and afford more efficient use of human wastewater biosolids resources. Resolutions from Regional Planning Councils across the state in support of this recommendation can be found here.

CLICK HERE FOR MORE INFORMATION ABOUT THE SUMMIT

Doc app

Document Center

The Document Center provides easy access to public documents. Click on one of the categories below to see related documents or use the search function.

Categories always sorted by seq (sub-categories sorted within each category)
Documents sorted by SEQ in Ascending Order within category

Biosolids Reading Materials8 documents

  • Wastewater Biosolids Nutrient Loading
    document seq 0.00
  • Toxic Algae
    document seq 0.00
  • Audubon
    document seq 0.00
  • Leg Budget Finance Committee
    document seq 0.00
  • Biosolids 2013 Summary
    document seq 0.00
  • Discussion Wastewater Biosolids
    document seq 0.00
  • Impediments To Implementation
    document seq 0.00
  • Harmful Algae
    document seq 0.00