Spatio-temporal variation of nitrate and nitrite levels in groundwater samples from Romania

This study investigated the spatial and temporal distribution of nitrate and nitrite concentration in groundwater from different geographical regions, in Romania. A special emphasis was put on a descriptive statistical analysis of data, namely on the determination of seasonal indices during dry and wet seasons. Nitrate and nitrite concentrations were monitored in 24 groundwater sources situated in different areas, between January 2016 and February 2020. The obtained data showed that the values of nitrate concentrations were situated between 8.03 mg/L in the North-Eastern part of Romania, 6.37 mg/L in the South-Eastern part of the country, and 3.55 mg/L in the Western part towards the center of the country. Nitrite concentration values were situated under the national maximum admitted limit, 0.5 mg/L, in all the investigated areas. The obtained data shows small changes in water quality during the monitoring period, which leads to the conclusion that, in this long interval of time, there were no significant groundwater contaminations with nitrate and nitrite. For adequate control of water pollution and rigorous management of groundwater sources, seasonal indices were calculated.