title: Erratum.
abstract: Results of a California state survey on ground water contamination were incorrectly reported in the article "Ground water ills: Many diagnoses, few remedies" by Marjorie Sun (News & Comment, 20 June, p. 1490). Six percent, not one-fifth, of California's large drinking water wells fed by ground water exceeded state pollution limits. One-fifth of the wells showed trace amounts of organic chemicals.