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account an updated Phosphorus Index when applying biosolids, in effect, limiting the application of Class B biosolids to the level of phosphorus that can be used by the plants as opposed to applying excess that may run off into the environment. When comparing the acceptable, permitted application of Class B biosolids on agricultural land to the Phosphorus Index (as demonstrated in the chart below prepared by JA staff). In the chart, each dot represents the calculated Phosphorus Index result from samples that were collected by OF/IFAS staff in biosolids application zones identified in the site's Nutrient Management Plan. The negative Phosphorus Capacity Index indicates that for those dots in red (below the P Balance line), the soil/plants have no additional capacity to hold/absorb the excess phosphorus. Any excess phosphorus deposited on site is susceptible to run-off or groundwater intrusion as opposed to being taken up by the soil and/or plants. This demonstrates that, by following the current rules, excess phosphorus has been and can continue to be applied in the BCL watershed unless regulatory changes are made. PCI 30 20 • P :Balance 10 e s • P Deficit -14 0;0 O o P Surplus _20 o O O -30 O -40 O O 60 50 O O -60 0 20 40 60 so 100 120 140 Lbs of total phosphorus applied per acre per year (2013-2017) CONCLUSIONS: The property owner at BCL has been very cooperative with the regulatory agencies and has voluntarily ceased any biosolid applications since May 2018. The property owner has allowed the regulatory agencies access to private property in orderto install data collection stations and collect samples to help understand the complex dynamics of weather, nutrient loadings and nutrient transport over time. The owner should be commended for his willingness to assist in this endeavor. Also of note is the detailed investigation process/plan that the FDEP, SJRWMD and IFAS put together to cooperatively work to gather this information and analyze it in a way that helps to determine what is/is not happening in the Upper Basin, including BCL. Staff from these organizations have been very professional and helpful in assisting the County with the results of their ongoing investigations. Some of the historical data collected have been analyzed by the County's consultant and are included as Attachment 2. FDEP staff has indicated that while the prior application rates and procedures used by the FDEP permittees for land application of biosolids followed the rules in effect at that time, it is evident that there are some inconsistencies with the way the program is structured. There has been a sustained upward trend in total phosphorus concentrations in BCL, which has a strong correlation to the increase in the regulated application of Class B biosolids within the BCL Watershed. While the data are compelling, studies from the regulatory agencies and experts continue and are not yet complete. 138