Everyone wants clean drinking water. And that desire has not declined on Long Island in the past 40 years. I know because I have tried to keep Long Island’s groundwater as clean and safe as possible over that time.
But as Long Islanders head out this spring to purchase fertilizers for their lawns and plants, they also should remember that the challenge to protect our drinking water has been marked by many efforts and few successes. We now have an opportunity to achieve a win-win outcome. This year, the State Legislature is again considering legislation that would require lawn fertilizer to be blended to be the best match for Long Island conditions. That means that the amount of nitrogen by weight in fertilizers should be reduced to 12 percent or less. Though some Long Island products can contain as much as 35 percent nitrogen, many fertilizer products meet the 12 percent requirement.
Also, the form of nitrogen should be slow-release (low solubility) rather than the rapid release, highly soluble form now sold on Long Island.
That matters because the sandy soil of Long Island does not filter out chemicals, such as nitrogen in fertilizers, that are dissolved by rain and slowly seep deeper into the ground. In the case of nitrogen, once it migrates past the root zone where plants can absorb it as a food, the dissolved nitrogen seeps even deeper until it reaches the groundwater. As much as 30 percent of lawn fertilizer can get into the groundwater.
At that point, nitrogen from fertilizers combines with other nitrogen sources such as septic and cesspool waste to pollute the groundwater, making it undrinkable unless it is treated. Expensive technology such as reverse osmosis is used by water departments to remove nitrogen from drinking water.
But excess nitrogen from fertilizer also runs off into streams, lakes and coastal water, adding to the nitrogen pollution harming fish and shellfish, wetlands and general water quality. About 7 to 16 percent of the nitrogen in coastal waters comes from fertilizer runoff.
By mandating that fertilizer sold on Long Island be mainly slow-dissolving and with reduced nitrogen content, we could eliminate one source of drinking-water pollution. Turf grass experts and fertilizer manufacturers say the new blend of fertilizer works just as well as their high-nitrogen counterparts in promoting and sustaining healthy lawns. Major fertilizer manufacturers resist the idea because it requires them to produce a different blend of the main ingredients. But people will still buy fertilizers to create green, healthy lawns even if the product’s composition is modified. And, at the same time, consumers and fertilizer manufacturers will help better protect our drinking-water supply and coastal ecosystems.
New to the debate is a counterproposal by the state Department of Environmental Conservation to change the instructions on fertilizers that puts the burden on customers to figure out new application rates. Why is the state so reluctant to put the burden where it belongs — on manufacturers? In the past, reformulating damaging products was simply common sense. A good example is the elimination of phosphates from laundry detergents in the 1980s. New York has required that all phosphates be removed from fertilizers sold in the state. Other measures also have banned products in New York State — including chlordane for termite control, aldecarb to kill potato beetles, and the use of methyl tertiary butyl ether (MTBE) in gasoline.
These actions were responses to products causing serious damage to drinking-water quality. State legislation to modify fertilizers sponsored by Assemb. Steve Englebright and Sen. Todd Kaminsky is a reasonable response to a well-documented problem. The DEC’s approach would be a gift to manufacturers that do not want to take responsibility for their role in this issue.
Sarah Meyland is an associate professor at New York Institute of Technology and director of the school’s Center for Water Resources Management.