Troubled Waters: Farm Pollution Threatens Drinking Water

Water that runs off fields treated with chemical fertilizers and manure is loaded with nitrogen and phosphorus, two potent pollutants that inevitably end up in rivers and lakes and set off a cascade of harmful consequences, contaminating the drinking water used by millions of Americans. Treating this water after the fact to clean up the contamination is increasingly expensive, difficult and, if current trends continue, ultimately unsustainable. The only solution that will preserve the clean, healthy and tasty drinking water that people expect is to tackle the problem at the source. This paper explains why. Nitrate, the most common form of nitrogen in surface and groundwater, is directly toxic to human health. Infants who drink water with high nitrate levels can develop an acute, life-threatening blood disorder called blue baby syndrome. High nitrate levels in water can also affect thyroid function in adults and increase the risk of thyroid cancer. Phosphorus stimulates explosive blooms of aquatic algae, including the especially dangerous cyanobacteria (blue-green algae) that produce toxins that can be deadly to pets, livestock, wildlife – and people. Toxins produced by cyanobacteria can harm the nervous system, cause stomach and intestinal illness and kidney disease, trigger allergic responses and damage the liver. Even after a brief exposure, cyanobacterial toxins can cause skin rashes, eye irritation and breathing problems.