Algae is choking our favorite springs, in part due to increased nitrate pollution. While research shows that lowered flows also play a part in algae growth in a more-complex-than-it-seems interplay of algae-friendly conditions, nitrate levels are a primary concern and something we absolutely have to address if we're serious about saving our state's iconic springs.
Nitrates enter the aquifer in runoff from farms, in the form of farm fertilizers and animal waste, from fertilizing our home lawns, and from human waste, septic tanks and wastewater. The pollution percolates into the aquifer below and resurfaces at spring vents.
To fix the pollution problem we have to understand and be honest about where the pollution is coming from.
Most Floridians who are aware that springs are polluted can name the culprits. But there doesn't seem to be much agreement on the numbers when people start discussing the details. We hear a lot of disagreements about what the "real problem" is at Florida's Springs. Which is fair; depending on where you live, the numbers are going to be slightly different. But let's start with a state-wide overview.
Combined data from the 26 Outstanding Florida Springs across the state that are impaired by pollution tells us that
70.3% of the nitrates entering our springs is from agricultural runoff. That includes farm fertilizers as well as animal waste.
17% of the nitrates entering our springs is from septic systems and wastewater treatment.
12.0% is from "urban fertilizer." That's home lawns, sports fields including golf courses, and city landscaping.
The biggest source of pollution we're going to have to reduce is undeniably, inconveniently,
Agriculture.
In fact, Agriculture contributes more than twice the nitrates to Outstanding Florida Springs as all other sources combined.
So now what does this mean? Where do we start?
First, we have to stop making the problem worse, no matter the source. That means stopping new pollution *before* it happens by:
Requiring all new residential and commercial developments to connect to advanced wastewater treatment facilities instead of continuing to allow new developments that add septic tanks if sewer connection is an option.
Prohibiting in-ground lawn irrigation systems in new developments. Adding irrigation to new development encourages new sources of home fertilizer runoff rather than more water-friendly home practices.
Placing a moratorium on new agricultural water use permits. Irrigation goes hand-in-hand with nitrogen runoff; issuing any new permits while simultaneously trying to reduce agricultural pollution is a waste of effort.
Then we have to deal with the existing pollution. That's where this data comes in handy. We have to be real about how much of the nitrate reduction needs to be assigned to each category of pollution source. How much is coming from from farm fertilizer, from septic tanks, from home fertilizers. Only then can we craft the right policies and projects capable of achieving the needed reductions. If agriculture is our primary source of nitrate pollution, the lion's share of our attention, funding, and efforts as a state should be helping our agricultural producers get the technology and assistance they need to remain productive while also protecting water.
Agriculture is the major source of nitrate pollution to our waterways. Therefore agriculture must be our target for the vast majority of the reductions in nitrates entering our waterways. Does this mean we ignore urban fertilizer and septic tank pollution? No, those are real issues that must be addressed, but even if they were eliminated most springs would still be polluted.
The challenge then is how agricultural pollution can be cut by the approximately 70% percent necessary to reach water quality goals. It will involve more advanced agricultural practices, like precision fertilizer placement and soil-moisture sensors. Agricultural producers will need cost-share programs to adopt these practices and remain profitable. But more importantly it will require large-scale conversions of intensive agriculture in the most sensitive spring recharge areas to non-polluting land uses like forestry. The map here shows the most vulnerable areas in blue and grey, where the aquifer is "unconfined" or "thinly confined," allowing surface pollutants to easily reach the aquifer below. These are the areas where intensive agriculture has the biggest impact on aquifer health.
These land conversions will require state funding for ongoing payments for farmers willing to convert their lands to less polluting uses. A similar model has been used successfully in Colorado, where farmers can voluntarily enter into an agreement to remove their land from intensive water use but remain economically viable. It essentially provides landowners with an income for providing clean water.
DIVE DEEPER
We discuss agricultural solutions in greater depth in "A Better BMAP for the Santa Fe River Springs." It includes realistic solutions and projects for a springs area with a high input of nitrates from agricultural sources. Dive in deeper to the topic HERE>