MAGNITUDE AND VARIATION OF THE MANGANESE, IRON AND AMMONIA IN DRINKING WATER FROM TIMIS COUNTY, ROMANIA

The aim of the per-formed study was to investigate the magnitude and variation of the manganese, iron and ammonia, as identified key issues, considering presence/absence of chlorination, area, prop-erty and time when the samples were collected. Material and methods: The observational case-study was conducted for 2 years (2016-2017) on a sample of 1,086 water sources in Timis County. A statistically significant difference (p<0.001) resulted between chlorinated and non-chlorinated sources for manganese and for iron mean-concentrations, Timisoara and Timis County (rural) public wells for manganese and for iron mean concentrations, and pub-lic and companies` wells in Timisoara for manganese. Results: Statistically significant dif-ferences of ammonia mean concentrations were also found between Timis County and Timisoara for public wells (p<0.001) and for companies (p=0.002), in non-chlorinated water. Calculated medians of manganese concentrations in well water were high in Timisoara (200 mu g/L) and in Timis County (95 mu g/L) and exceeded MAC (50 mu g/L). The highest concentra-tion of manganese (500 mu g/L) was recorded in Timisoara, in 2016. Median of iron (93 mu g/L) concentrations in public wells in Timis-County (rural) was much higher than median (50 mu g/L) in public wells in Timisoara. Both median values didn`t exceed MAC (200 mu g/L). Still, the highest mean concentration of iron (3,780 mu g/L) was found in a public well from Timisoara, in 2016. Median of ammonia concentrations in public wells (non-chlorinated wa-ter) in Lugoj (0.6 mg/L) also surpassed MAC (0.5 mg/L). Conclusions: excessive concentra-tions of manganese, iron and ammonia were found in drinking water in Timis County, with significant variation in space, time and depending on property and chlorination.