Scientific Investigations Report 2007–5179
U.S. GEOLOGICAL SURVEY
Scientific Investigations Report 2007–5179
Figure 26. Relation of solvent detection frequencies in ground-water samples collected from (A) urban and (B) agricultural areas to dissolved-oxygen concentration within regional National Water-Quality Assessment Program study units in the arid to semiarid Western United States, 1993–2004. See figure 24C for percentage of agricultural and urban wells within each dissolved-oxygen category.