For two decades, Florida has had an annual limit on how much phosphorous can flow out of the Everglades Agricultural Area -- a region of farmland south of Lake Okeechobee. Farmers and sugar-growers must release at least 25 percent less phosphorous than they did before the limit.
Until this year, farmers haven’t had much trouble making this goal, which was established in 1996 by the Everglades Forever Act. They have a near-perfect record of exceeding the 25 percent reduction standard -- often by as much as 40 percentage points.
This year, the farmers beat the 25 percent goal again, releasing 27 percent less phosphorous. But they struggled more than usual because of very heavy rains.
"They had the rainiest year since 1932," said Melanie Peterson, a member of the South Florida Water Management District's governing board. "Any time the ground is saturated, you're going to have an issue where it's going to be difficult to either contain or control nutrient runoff."
The heaviest rain came right in the middle of growing season -- when phosphorus levels are highest because of the fertilizers used in the growing process. Extra water from the rain interfered with the closed canal systems that usually keep phosphorous on the farms. And farmers had to deal with heavier-than-normal runoff from other areas near Lake Okeechobee.
"The fact that they accomplished 27 percent in such a historically wet year is, I think, commendable, really... It's just super commendable," Peterson said.
But critics of the reduction goal program say this year's success is just another indicator that it's time to either raise the goal from 25 percent.
Dr. Melodie Naja, chief scientist for the Everglades Foundation, pointed out that in 1996, the first year of full implementation of the reduction program, farmers released 68 percent less phosphorus -- well above the 25 percent required reduction.
"In just the first compliance year... that's really very high," Naja said. "Normally when you implement best management practices, you could expect several years to see an impact on water quality."
Naja said there’s also a problem with using a standard based on averages.
"Basically, the bad neighbors are counting on the good neighbors to achieve the 25 percent."
Naja said measuring the load of phosphorus that reaches the Everglades would be a better measure of farmers' success in reducing their phosphorus releases. She also recommended that individual farms be held accountable for the amount of phosphorus they release.
"We need to target those specific hotspot areas," Naja said.