Algae is choking our favorite springs, in part due to increased nitrate pollution. Research shows that lowered flows also play a part in algae growth in a more-complex-than-it-seems interplay of algae-friendly conditions.
Nitrates enter the aquifer in runoff from farms, fertilizing our home lawns, and from septic tanks. The pollution percolates into the aquifer below and resurfaces at spring vents.
By the way, the image that bottlers market of spring water being "pure" is just that - marketing! Water that is coming from the vent of a spring is carrying those pollutants picked up from the surface of surrounding land.
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, so let's settle it.
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.
14.8% of the nitrates entering our springs is from septic systems.
12.0% is from "urban fertilizer." That's home lawns, sports fields including golf courses, and urban landscaping.
It's 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?
First, we have to stop making the problem worse. That means stopping new pollution at the source by:
Requiring all new residential and commercial developments to connect to advanced wastewater treatment facilities.
Prohibiting in-ground lawn irrigation systems and the use of lawn fertilizer containing nitrogen on new lots.
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.
Agriculture is the major source of pollution and, therefore, must be responsible 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 approximately 70% percent. 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 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. Particularly in areas where the aquifer is most vulnerable, the "unconfined" areas, where there is easy transference of pollutants from the surface to our aquifer below.
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>