Nitrogen Targets

There are several established targets for ambient total nitrogen concentrations established by the EPA, the SJRWMD, and the SFWMD for different regions of the IRL. A combination of the established targets wase used to be as conservative in protecting the lagoon’s health as possible. The EPA targets were used for the ML; the SJRWMD targets for the BRL, CIRL, and NIRL; and the SFWMD target for the SIRL.

Total Nitrogen Targets

For the ML, the targets established by the EPA were chosen as they were being used by the SJRWMD and no other targets were available. For the BRL and NIRL, there were three potential available targets to choose from: monthly maxima, annual medians, and annual geometric means.

The SJRWMD annual median target was chosen because geometric means (EPA recommended target) were typically less protective of the Lagoon than the District’s median targets. For the CIRL, the SJRWMD annual median targets specific to the north and southern regions were selected (Steward, Lasi, and Phlips, 2010). Finally for the SIRL, the SFWMD’s conservative criteria of annual median was used as target for all three sublagoon areas.

Targets for the ML have only been established by the EPA and are more restrictive than the currently proposed targets for the Reasonable Assurance Plan (RAP). Since the RAP is still undergoing review, the stricter targets were adopted for assessment purposes.