TABLE 1-2 Perchlorate Drinking-Water Concentrations Based on Monitoring Data from Unregulated Contaminant Monitoring Rule as of May 2004

 

Perchlorate

Samples

Location

Minimal Concentration (ppb)a

Maximal Concentration (ppb)

Median Concentration (ppb)b

Number above MRL

Total

Fraction below MRL (%)

United States

<4

200c

6.4

535

28,179

98.1

Puerto Rico

<4

420

NA

1

734

99.9

California

<4

67d

6.7

364

8,179

95.5

a1 ppb = 1 µg/L.

bMedian perchlorate concentration of values above the minimum reporting level (<4 ppb).

cMaximum in United States was measured in Duval County, Florida.

dMaximum in California was measured in San Bernardino County. Abbreviations: MRL, minimum reporting level (<4 ppb); NA, not applicable.

Source: Data from EPA 2004a.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement