[Nitrate concentration in drinking water in southwest Lower Saxony]

The investigation of 8544 water samples from central water supply plants and of about 20,000 from own water supply plants of Southwest Lower Saxony with respect to nitrate pollution showed that 97.5% of the samples from the central water supply plants and of 63.6% from the own water supply plants contained nitrate concentrations lower than 50 mg/l. On the other hand, the nitrate concentrations of samples from own water supply plants were in 12.5% more than 90 mg/l and in 24.0% between 50 and 90 mg/l. There was a remarkable tendency of increasing of the nitrate pollution comparing the data from 1979 and 1984. The nitrate concentrations correlated well with the depth of the wells but not with bacteriological findings.