*Rainbow shares a BMAP with Silver, but we break down the data for each individually.
When DEP released its updates to Springs BMAPs in 2024, the Florida Springs Council dug into the updated data to answer three questions:
1. Where is the nitrogen pollution coming from for this springshed?
2. What is the difference in pollution levels in this springshed since the 2018 BMAPs were adopted?
3. How is it going? That is, has this BMAP been successful so far, and where has the 2018 BMAP put this springshed on its path to restoration?
Sources of Nitrogen Pollution in Rainbow Springs and River
The largest contributor of nitrogen pollution to Rainbow is agriculture at just over 35%, followed closely by septic tanks at 30%.
OSTDS = Onsite Sewage Treatment and Disposal Systems - septic tanks
Atmo. Dep. = Atmospheric Deposition. This comes from the air or rainfall and is not a source that can be reduced.
Agricultural sources (livestock, dairies, farm fertilizers, nurseries) are in shades of green.
Development/urban sources (urban and sports fertilizers wastewater and septics) are in shades of yellow and orange.
The difference in pollution levels and required nitrogen reduction since the 2018 BMAPs were adopted
Since 2018, the amount of nitrogen measured at spring vents increased by 650,000 pounds per year, a 30% increase.
Pounds per year of nitrogen at the spring vents - data are based on DEP's actual measurements.
How is it going?
Rather than decreasing, nitrogen levels have increased at Rainbow Springs.
The first black dot at 2018 is based on actual data, how much pollution was measured at the spring vent when the 2018 BMAP went into effect.
The next two dots show how things are going right now.
The white dot at 2023 shows where the 2018 BMAP should have gotten us. The white line shows the pollution level goals established by the 2018 BMAP, with reductions in nitrogen levels over the next 20 years to reach water quality goals in 2038.
The second black dot shows where pollution levels actually are. For Rainbow, total pounds of nitrogen measured at the spring vent has increased.
DEP's goal for 2018 was to reduce nitrogen in Rainbow Springs and River by 30%. Instead, it increased by 30%, putting Rainbow further behind, with less time left to reach water quality goals by 2038 as required by law.
DEP's new goal for 2028 is to get back to the same level of nitrogen pollution we started with in 2018. The best case scenario will be that DEP will have spent ten years and millions of dollars for Rainbow to be just as polluted as it was when the BMAP was first put into place.
TMDL = Total Maximum Daily Load. That is the water water quality goal - the level of nitrogen coming from the spring vent at which the spring system will no longer experience ecological harm.
Why is the TMDL, or water quality goal, set higher for 2024? Increased rainfall/increased flow since the 2018 BMAPs means that more total pounds of nitrogen can be measured at the spring vent while the overall concentration in the water remains the same.
This four-minute video excerpt from the larger BMAP updates discussion covers Rainbow Springs and River and will walk you through the information presented here.
For a deeper understanding of the BMAP updates, watch Executive Director Ryan Smart explain this analysis in a one-hour "Springs BMAPs - Live Discussion" video, found at floridaspringscouncil.org/springsbmaps
Questions about these graphs and the Springs BMAP update process? Email smart@floridaspringscouncil.org