Drinking Water Blues: Nitrate Pollution from Coast to Coast

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Manure being applied to a farm field. Fertilizers - whether manure or the much more prevalent synthetic variety - are often spread on fields in excess of crop needs, leading to increased nutrient runoff.

It's the tail end of Drinking Water Week, when we're supposed to celebrate the generally amazing U.S. drinking water supply, yet they're singing the blues in California's Central Valley and New York's Suffolk County. The two regions may be miles away in geography and in culture, but both share one major, unfortunate commonality; namely, that their drinking water is heavily polluted by nitrates. Two separate studies (from University of California-Davis and the Suffolk County's Department of Health Services, respectively), both out in late winter 2012, outline the troubles facing each locale.

Nitrates occur when nitrogen, primarily from sources like synthetic fertilizers, animal manure and human excrement combine with organic chemicals like ammonia to form the invisible, odorless and tasteless compound. Drinking water with elevated nitrate levels is detrimental to human health and is associated with respiratory and reproductive system illness, some cancers, thyroid problems and even "blue baby syndrome." From an ecological standpoint, too much nitrogen and nitrate runoff can cause eutrophication, or nutrient loading in surface and marine waters that result in algal blooms that create those notorious oxygen-starved "dead zones" and "red tides" that kill off aquatic life.

One of the most productive and intensively farmed agricultural areas in the world, the Central Valley relies greatly on fertilizer so nitrate pollution is a problem that has been studied extensively there. However, the UC-Davis report revealed that nitrate pollution in groundwater is increasing, and is especially acute for people living in the Tulare Lake Basin and Salinas Valley regions, where an estimated 10 percent of the often impoverished 2.6 million people living there are consuming nitrate-heavy drinking water. As the area's dominant economic sector, agriculture accounts for 96 percent of total nitrate water contamination, including 54 percent from synthetic fertilizers and 33 percent from animal manure.

Making matters worse is the cumulative effect of nitrate build-up present in soils. Through water runoff and soil erosion, nitrates will continue to plague surface and groundwater for many years to come. If nitrate pollution goes on unchecked, an estimated 80 percent of those in the Tulare Lake Basin and Salinas Valley will be at risk to experience negative health and financial consequences. (For detailed coverage of the UC-Davis study and the real impact of nitrate contamination on Central Valley residents, read California Watch's special reports.)

3,000 miles east, in the very different setting of suburban Suffolk County, part of the New York City metro area, alarm bells went off when the Department of Health Services, which governs water quality for the county, released a draft water resources report detailing the rise in water pollution, with elevated nitrate concentrations being the greatest concern. Two features make Suffolk County's nitrate pollution problems unusual. First, Long Island is an EPA-designated sole source aquifer, which means that all county residents receive their drinking water from the groundwater under their feet. Secondly, only about one-quarter of the 1.5 million people in Suffolk County have community or municipal wastewater systems, with the rest depending on around 400,000 septic systems buried in homeowners' yards. It's not difficult to grasp the source of the excessive nitrate loads when human waste is discharged from a multitude of failing underground septic systems directly into groundwater, or as the Long Island Press describes it: "Yes, Suffolk County residents are drinking the same water they flush their toilets into."

To a great extent, faulty septic systems are the source of nitrate pollution here, but just as in the Central Valley, fertilizer runoff is also a contributor. The county's east end farms are to blame, but so are residential lawns. In a recent GRACE-produced video, Dr. Chris Gobler, a professor at Stony Brook University's School of Marine and Atmospheric Sciences and a nitrogen pollution expert says, "High levels of nitrogen - associated with residential septic tanks and cesspools and fertilizer runoff from agricultural lands - in the groundwater has led to the degradation of local drinking water supplies as well as Long Island's coastal ecosystems."

Nitrate water contamination is a prime example of the difficulties in addressing nonpoint source pollution (where there is no single source of attributable pollution but many contributors). With numerous sources covering an often widespread area, nonpoint source pollution makes it not only difficult to track but often harder to see. This more insidious form of pollution is a stark contrast from the commonly held picture of the easily identifiable toxic nastiness gushing from an industrial plant pipe.

Yet the nitrogen and nitrate water contamination crises don't go unnoticed. The release of these two studies have sounded the alarm in those two regions and there are at least two other recently issued reports that raise concerns, one from the European-focused Soil Association and another from the Environmental Working Group. Broader in scope, these additional reports implicate agriculture and its industrial overuse of synthetic fertilizers as the biggest culprit in the nitrogen overdose in water around the world. Without agriculture, especially industrial agriculture, stepping up to address their overwhelming contribution to the flow of nitrates, nitrogen and phosphorus into the world's waters, there will be no remedying the situation.

Is there hope? Are there solutions to reducing nitrogen and nitrate contamination in water? Yes and yes. For agriculture there are best practices like limiting fertilizer application, the use of organic farming methods and tailwater ponds designed to capture runoff. In the case of septic systems, Maryland has taken the innovative approach of offering grants for people to upgrade their septic systems and improve nitrogen removal.

As important as it is to praise U.S. water quality during Drinking Water Week, a warning has been delivered along with these reports. Whether it's the more-is-always-better approach of agricultural fertilizer application in the Central Valley or laissez-faire attitude towards septic system disposal and residential lawn over-application in Suffolk County, loading our waters with nitrogen and nitrates creates a health risk for humans and the ecosystem alike. Nitrates in drinking water, which often go unnoticed by those who drink it, present an unacceptable risk from coast to coast, and many places between.