investigating the amount of nitrate and nitrite density in drinking water wells in villages around the industrial estate, city of orumieh

background: nitrate and nitrite compounds are considered as groundwater’s contamination factors, which in recent years, their densities have been growing in these resources. this study was conducted aiming to measure nitrate and nitrite density in drinking water wells in villages around the industrial estate, city of orumieh, and to compare them to the approved standards. methods: this was a descriptive, analytical, cross section study. the samples were taken from 30 wells in different parts of the surrounding areas of the industrial estate within a year period and the densities of nitrate and nitrite were measured. findings: based on the findings of the experiments, the annual mean density of nitrate and nitrite were respectively 17.46 mg/l and 0.008 mg/l.  the highest nitrate concentration was related to the winter. anova was used to compare the mean density of nitrite and nitrate in different seasons. the assessment showed that the average nitrate density was significantly different comparing spring and summer and also spring and autumn (p<0.05), but there was not any significant differences in nitrite’s mean density in different seasons (p<0.05). also, a statistically significant relationship were established between nitrate levels and the water depth (p<0.001, r=0.76), with increasing the water depth, the wells nitrate density decreased. conclusion: based on the findings of the study it can be concluded that studied water quality is currently in accordance with drinking water standards in iran with regards to nitrate and nitrite concentration; however, continuous control of water resources is essential. hence, monitoring, treatment and disposal of production waste water should also be considered.