Field measurements of nitrate leaching below Willamette Valley row and mint crops

Abstract

According to the United States Geological Survey, 9 percent of wells in the Willamette Valley exceed the EPA’s 10 ppm drinking water standard for nitrogen in the NO3– compound, or NO3–-N. A study of 281 domestic drinking water wells in Lane County showed that 22 percent of the wells exceeded the same standard (Penhallegon, 1994). In a 2000–2001 study of 476 wells in the southern Willamette Valley, 35 wells exceeded the drinking water standard, with 21 percent of the total wells exceeding 7 ppm NO3 –-N (DEQ, 2002). Other studies have shown high concentrations of NO3–-N within water draining from experimental fields planted in corn, broccoli, and snap beans (Sattell et al., 1999). Exposure to high concentrations of NO3 – is known to cause breathing complications in infants (Weisenburger, 1993) and has been linked to cancerous tumors in laboratory animals (Pierzynski et al., 1994).