According to a 1999 NRDC study, in which roughly 22 percent of brands were tested, at least one sample of bottled drinking water contained chemical contaminants at levels above strict state health limits. Some of the contaminants found in the study could pose health risks if consumed over a long period of time. The NRDC report conceded that "most waters contained no detectable bacteria, however, and the level of synthetic organic chemicals and inorganic chemicals of concern for which were tested were either below detection limits or well below all applicable standards." Meanwhile, a report by the Drinking Water Research Foundation found that of all samples tested by NRDC, "federal FDA or EPA limits were allegedly exceeded only four times, twice for total coliforms and twice for fluorides."