Heavy metal contaminations in the groundwater of Brahmaputra flood plain: an assessment of water quality in Barpeta District, Assam (India).

A study was conducted to evaluate the heavy metal contamination status of groundwater in Brahmaputra flood plain Barpeta District, Assam, India. The Brahmaputra River flows from the southern part of the district and its many tributaries flow from north to south. Cd, Fe, Mn, Pb, and Zn are estimated by using atomic absorption spectrometer, Perkin Elmer AA 200. The quantity of heavy metals in drinking water should be checked time to time; as heavy metal accumulation will cause numerous problems to living being. Forty groundwater samples were collected mainly from tube wells from the flood plain area. As there is very little information available about the heavy metal contamination status in the heavily populated study area, the present work will help to be acquainted with the suitability of groundwater for drinking applications as well as it will enhance the database. The concentration of iron exceeds the WHO recommended levels of 0.3 mg/L in about 80% of the samples, manganese values exceed 0.4 mg/L in about 22.5% of the samples, and lead values also exceed limit in 22.5% of the samples. Cd is reported in only four sampling locations and three of them exceed the WHO permissible limit (0.003 mg/L). Zinc concentrations were found to be within the prescribed WHO limits. Therefore, pressing awareness is needed for the betterment of water quality; for the sake of safe drinking water. Statistical analysis of the data was carried out using Special Package for Social Sciences (SPSS 16).

Distribution of water quality parameters in Dhemaji district, Assam (India).

The primary objective of this study is to present a statistically significant water quality database of Dhemaji district, Assam (India) with special reference to pH, fluoride, nitrate, arsenic, iron, sodium and potassium. 25 water samples collected from different locations of five development blocks in Dhemaji district have been studied separately. The implications presented are based on statistical analyses of the raw data. Normal distribution statistics and reliability analysis (correlation and covariance matrix) have been employed to find out the distribution pattern, localisation of data, and other related information. Statistical observations show that all the parameters under investigation exhibit non uniform distribution with a long asymmetric tail either on the right or left side of the median. The width of the third quartile was consistently found to be more than the second quartile for each parameter. Differences among mean, mode and median, significant skewness and kurtosis value indicate that the distribution of various water quality parameters in the study area is widely off normal. Thus, the intrinsic water quality is not encouraging due to unsymmetrical distribution of various water quality parameters in the study area.