Table 2 Test results of rural groundwater drinking water quality in Yantai from 2015 to 2018
Year | Nitrate nitrogen content (mg/L) | Number of samples | Qualified rate(%) |
|---|---|---|---|
2015 | 23.4 ± 18.1 | 836 | 48.33 |
2016 | 23.2 ± 18.2 | 400 | 49.50 |
2017 | 27.1 ± 21.1 | 572 | 45.80 |
2018 | 15.7 ± 14.4 | 540 | 51.30 |
Total | 21.9 ± 18.3 | 2348 | 48.59 |