Data on Nitrate–Nitrite pollution in the groundwater resources a Sonqor plain in Iran

Nitrate is a groundwater pollutant which in higher concentrations limits, leads to health hazard such as Methemoglobinemia and formation of nitrosamine compounds. In this research, the nitrate and nitrite concentrations in all water resources in the villages of Songor plain were determined and the relationship between these values with the water table and zonation of nitrate concentration were investigated in the GIS environment. In this study, 37 samples of all groundwater resources of Sonqor plain were taken in, high water (March 2016) and low water (October 2017) periods. Water nitrate levels were then determined by spectrophotometry and results compared with national standards of Iran and analyzed by SPSS. Finally, the concentration distribution mapping was carried out in GIS environment and the factors affecting nitrite changes were analyzed. Nitrate concentration of water resources of Sonqor plain was fluctuating at 3.09–88.5 mg per Liter. In one station, nitrite concentrations in the high (88.5 mg/L) and low (71.4 mg/L) water seasons were higher than the maximum limit. Low thickness of alluvium, the site of wells in the downstream farmlands, the farming situation of the region, nitrate leaching from agricultural soils and wide use of nitrogen fertilizers in agriculture were considered as the causes of the pollution in one station. Though the average concentration of nitrate and nitrite are not high in this region, but because of problematic consequences of high nitrate concentrations to human health, proper management in use of chemical fertilizers, treatment or disposal of contaminated wells and protection of water wells is highly recommended.

from agricultural soils and wide use of nitrogen fertilizers in agriculture were considered as the causes of the pollution in one station. Though the average concentration of nitrate and nitrite are not high in this region, but because of problematic consequences of high nitrate concentrations to human health, proper management in use of chemical fertilizers, treatment or disposal of contaminated wells and protection of water wells is highly recommended.
& 2018 The Authors. Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Subject area
Chemistry More specific subject area Water monitoring and quality Type of data Increasing the amount of nitrate above the permissible level can lead to health problems such as Methemoglobinemia.
Though the average concentration of nitrate and nitrite are not high in this region, but because of problematic consequences of high nitrate concentrations to human health, proper management in use of chemical fertilizers, treatment or disposal of contaminated wells and protection of water wells are highly recommended.

Data
Concentration of studied Nitrate-Nitrite in the groundwater of the Sonqor region are summarized in Tables 1-4 and mapping GIS in Figs. 1-4.

Study area description
Sonqor is located at 85 km distance, east north of Kermanshah and 1700 m above sea level [1]. The city's population is 51 thousand and contains two districts, two cities, eight rural district and 239 countries. Among countries, 220 ones are haunted and the rest is not inhabited. High level above sea and latitude, have leaded to cold weather formation. The most annual average temperature goes around 17.8 and lowest one is 3.5°C. The average annual precipitation in Jamishan Dam Lake is approximately 441 mL, with highest precipitation rate on March (79.6 mL) and lowest rate on September month (0.1 mL) are estimated (Fig. 5).

Sample collection and analytical procedures
To evaluate quality of groundwater resources in villages of Sonqor plain, after water resource exploration as the matter of nitrate and nitrite ions, Identification of whereabouts of each groundwater resources which constitute the main potable water resource of villages, Considering the direct relation of nitrate concentration to amount of usage nitrogen containing fertilizer and different irrigation and precipitation in both low and high rate seasons, sampling was conducted in all water ground resource congaing 37 villages resources governed by rural water and waste water  organization of Sonqor plain in two times periods. First, March 2016, as the high rate precipitation period and the next period was October 2017 as low rate precipitation. The sampling was carried out in similar areas within one year. Nitrate and nitrite concentrations were determined using spectrophotometry and compared with internal standards [2][3][4][5][6][7][8][9][10][11].
To so sampling, polyethylene bottles with 1-L volume were used and samples were transferred to lab. The whole sampling steps, transferring and data analysis were conducted according to standard method of nitrite and nitrate quantification, exploiting DR5000 Spectrophotometer [12][13][14][15][16][17][18][19][20]. Finally, acquired results were compared with internal standards (Institute of Standards and Industrial Research of Iran. No: 1053) [2,[21][22][23][24][25]. In the proses, three fountains of Aliabad villages got dried out, the sampling was carried out in low rate rain period. The acquired raw data was analyzed by GIS software and after processing, color zoning was prepared using GIS software version 9.3. The criteria that were analyzed by GIS software are including; topography, farms applications, geology, agrology, hydrology and quality of regional water resources.