Geology, lineaments, and sensitivity of groundwater to radon gas contamination

Activity concentration and sensitivity of groundwater to radon contamination, and simple and sustainable radon mitigation possibilities have been studied and presented. Radon concentrations in groundwater at point of source (well site), point of use (homes), emission and exhalation rates from rock material (aquifer materials), as well as effects of mitigation measures (storing water in pot before use) of radon in drinking water from the area were also evaluated. Radon activity concentration (Bq/m3) in studied groundwater at point of source ranges between 731 ± 5 and 84,300 ± 530, and at point of use (homes) the mean values recorded range from 276 ± 14 to 8010 ± 98 Bq/m3. Radon emission and exhalation from aquifer materials in the area ranged between 62.5 ± 4–150 ± 10 Bq/m3 and 2.93–6.0 Bq/m2/h. It was observed that high radon concentration in the studied groundwater were recorded in well drilled in areas underline by granite and gneiss, where fractures were the main targets for groundwater abstraction. The study revealed that boreholes drilled in these areas and fitted with hand pump had the highest radon concentration. It is therefore concluded that radon distribution in groundwater of the area is closely related to the geology, structures (fractures), and wells type. It is observed that the traditional way of collecting and storing groundwater from wells in clay pot before use as practiced by inhabitant of the area resulted in reducing radon concentration at homes with as much as 94.95% in Kundiga and 62.24% in Jara Dali. Therefore, this can be regarded as a good, sustainable, and effective mitigation measures for radon gas-contaminated groundwater. © 2017, Springer International Publishing AG.