Well water contamination in a rural community in southwestern Pennsylvania near unconventional shale gas extraction.

Reports of ground water contamination in a southwestern Pennsylvania community coincided with unconventional shale gas extraction activities that started late 2009. Residents participated in a survey and well water samples were collected and analyzed. Available pre-drill and post-drill water test results and legacy operations (e.g., gas and oil wells, coal mining) were reviewed. Fifty-six of the 143 respondents indicated changes in water quality or quantity while 63 respondents reported no issues. Color change (brown, black, or orange) was the most common (27 households). Well type, when known, was rotary or cable tool, and depths ranged from 19 to 274 m. Chloride, sulfate, nitrate, sodium, calcium, magnesium, iron, manganese and strontium were commonly found, with 25 households exceeding the secondary maximum contaminate level (SMCL) for manganese. Methane was detected in 14 of the 18 houses tested. The 26 wells tested for total coliforms (2 positives) and E. coli (1 positive) indicated that septic contamination was not a factor. Repeated sampling of two wells in close proximity (204 m) but drawing from different depths (32 m and 54 m), revealed temporal variability. Since 2009, 65 horizontal wells were drilled within a 4 km (2.5 mile) radius of the community, each well was stimulated on average with 3.5 million gal of fluids and 3.2 million lbs of proppant. PA DEP cited violations included an improperly plugged well and at least one failed well casing. This study underscores the need for thorough analyses of data, documentation of legacy activity, pre-drill testing, and long term monitoring.

Concentration of natural radionuclides in raw water and packaged drinking water and the effect of water treatment.

The raw water (RW) samples collected from natural sources are subjected to water treatment process, including reverse osmosis (RO), and are packed in bottles as packaged drinking water (PDW). Raw water (21 samples) taken from deep wells of Chennai and Secunderabad which are used in the production of PDW, were analysed for (234)U, (235)U, (238)U, (226)Ra, (228)Ra and (210)Pb activity concentrations. Activity Concentrations of (234)U, (235)U, (238)U, (226)Ra, (228)Ra, (210)Pb and (210)Po in PDW were also analysed. The mean activity concentrations of (234)U, (235)U, (238)U, (226)Ra, (228)Ra and (210)Pb in RW at Chennai were 12.1, ≤1.3, 7.1, 2.6, 27.5, and 16.3 mBq/L respectively. The mean activity concentrations of (234)U, (235)U, (238)U, (226)Ra, (228)Ra and (210)Pb in RW at Secunderabad were found to be 40.9, 1.7, 41.5 84.5, 100.1, and 17.0 mBq/L respectively. The mean concentrations of (234)U, (235)U, (238)U, (226)Ra, (228)Ra, (210)Pb and (210)Po in PDW at Chennai were found to be ≤1.3, ≤1.3, ≤1.3, ≤0.2, ≤1.7, 28.0 and 1.2 mBq/L at Secunderabad were found to be ≤1.3, ≤1.3, 1.7, 4.3, 5.0 and 28.1 mBq/L. The study indicated a considerable reduction in the concentration of natural radionuclides due to water treatment. The reduction ratios of RW to PDW for (234)U, (238)U, (226)Ra, (228)Ra were 97, 96, 94 and 95%. In case of (210)Pb, the PDW showed higher concentration of (210)Pb than RW. This was due to its in growth from (222)Rn which was not removed in the RO process.

Radon concentration in drinking water and supplementary exposure in Baita-Stei mining area, Bihor county (Romania).

The radon concentration was measured in the drinking water of public water supply and private wells located in the mining area of BaiTa-Stei, Bihor County, Romania. The measurements were performed using the LUK-VR system based on radon gas measurement with Lucas cell. The results show that the radon concentrations are within the range of 1.9-134.3 kBq m(-3) with an average value of 35.5 kBq m(-3) for well water, 18.5 kBq m(-3) for spring water and 6.9 kBq m(-3) for tap water. Comparing with previous data from the whole of Transylvania, the average value is two times higher, proving this zone to be a radon-prone area. From the results of this study the effective dose to the population is between 4.78 and 338.43 µSv y(-1). These doses are within the recommended limits of the world organisations.