Laserfiche WebLink
State Water Resources Control Board <br /> Division of Water Quality <br /> GAMA Program <br /> NITRATE OCCURRENCE <br /> Anthropogenic Sources The largest source of anthropogenic nitrate is industrial production <br /> via the Haber-Bosch process. The Haber-Bosch process catalyzes <br /> atmospheric nitrogen gas with hydrogen to produce ammonia — <br /> which can then be further oxidized to produce nitrate. <br /> Approximately 3 to 5 percent of the world's natural gas production is <br /> consumed in this process, producing approximately 450 million tons <br /> of nitrogen fertilizer per year. High concentrations of nitrate are <br /> often associated with fertilizer production and application. Fertilizer <br /> that is not used by plants can leach into groundwater and ammonia <br /> will rapidly convert to nitrate in the presence of oxygen. <br /> Other anthropogenic sources of nitrate to groundwater include <br /> septic systems, discharges from wastewater and agricultural ponds, <br /> leaky sewer lines, manure fertilizer application, and the production <br /> of explosives. <br /> Natural Sources Nitrogen is an important biologic element and is a required <br /> component of amino acids and proteins. Although nitrogen is the <br /> most abundant gas in the atmosphere (as N2), it is not easily used <br /> by most organisms in this form. N2 must first be transformed to a <br /> more easily utilized compound, such as nitrate, before incorporation <br /> into biologic tissue or plant matter. <br /> Nitrate is naturally produced from N2 through biologic fixation and <br /> from organic nitrogen through mineralization. Minor amounts may <br /> also be produced through oxidation of atmospheric nitrogen by <br /> lightening. Some nitrate from these sources may naturally enter <br /> groundwater. However, these concentrations are generally low. <br /> Nitrate concentrations greater than 10 to 15 mg/L (as NO3) are <br /> generally indicative of anthropogenic nitrate sources (Mueller, <br /> 1995). <br /> Revised November 2017 3 <br />