Assessment of water security challenges in hilly terrain of Bangladesh: an insight of quantity and quality concerns and implementation of effective solutions

The water supply systems in hilly regions of Bangladesh predominantly rely on surface water, particularly spring water. Groundwater is an alternative, but extraction is difficult due to the intricate geological profile, significant aquifer depth from the hilltop, and complicated hydrogeological structure. This study investigates the water quality and availability of potable water in the hilly region of Sajek, Rangamati. The research was conducted by analyzing 39 water samples, a survey involving 156 participants, and two focus group discussions. The water quality was assessed by collecting samples of tank storage, spring, chara (small pond), and drinking water. The study of the water quality parameters exposed the extreme conditions of the drinking water sources in the area. The mean total coliform (TC) and faecal coliform (FC) in June ranged from 2 CFU/100 ml to 163 CFU/100 ml, with the highest TC measured at 163 CFU/100 ml in spring water samples and the highest value of FC measured in chara water 149 CFU/100 ml. In October, the highest TC value recorded for the spring water samples was 174 CFU/100 ml, and FC was 155 CFU/100 ml, which exceeds the national limit of 0 CFU/100 ml. Spring water showed the highest turbidity of 13.97 NTU compared to other months and all the water sources. In June, the total dissolved solid (TDS) was the highest (54.333 mg/l) in the chara water sample and the lowest in the DW 2 sample (23.967 mg/l). The finding shows presence of potentially harmful bacteria in all water samples, indicating that none of the water sources are safe for drinking and require treatment before consumption. Considering the water quantity, community perception analysis revealed that almost all respondents attribute this scarcity to increased tourist numbers, high water costs, and dependence on a single spring water source. The cost of water in Sajek is 5 times higher compared to Chittagong WASA (CWASA), highlighting severe water crisis. Another finding revealed that the community lacks adaptive technologies to address water scarcity effectively, as they do not utilize or develop appropriate strategies. To overcome these problems the study concludes by finding a community-based model that outlines the responsibilities of stakeholders, including local and central governments, non-governmental organizations (NGOs), and community members which will be effective for reducing the scarcity of the safe drinking water.