Isotopic Tracing of Perchlorate Sources in the Environment

Figure 4

δ³⁷Cl (‰) versus δ¹⁸O (‰) values and Δ¹⁷O (‰) versus δ¹⁸O (‰) values show stable isotope data for ClO₄⁻ in groundwater samples from the Chino Basin, California (blue symbols) [56], Long Island, New York (yellow symbols) [57], and southeastern San Bernardino Basin, California (red symbols) [58] in comparison to the principal known source types in the region, which is shown in Figure 1.