Coastal areas of Bangladesh have been facing increasing salinity of surface water and groundwater. This study provides the approximate scope of the problem in a coastal area of southeaste Bangladesh by using less-ac-curate, but lower-cost salinity measuring devices that enable local people to assess the situation. Ten local women were employed to monitor 10 tube wells each on a weekly basis, from mid-February to mid-May, during the 2016 dry season. Geographical Information System and time series clustering were used to visualize the spatial distribution and seasonal change of the salinity levels. In addition, the tube well users were asked about the salt consumption in their daily diet. One-third of the monitored tube wells were found to contain more sodium than the tolerable level in terms of taste suggested by the World Health Organization. However, the mean salinity level across all monitored tube wells was much lower. The salinity level varied depending on the depth of the tube wells rather than their locations or altitudes, and those deeper than 200 m were likely to be salt free. The results of the diet survey showed that wealthier households tended to use more salt in their daily diets, but at the same time they tended to have deeper tube wells that are less likely to contain high levels of sodium.