Determinants of Households’ Access to Improved Water Sources, Geospatial Modelling and Water Quality Monitoring in Talensi District

Abstract

The study assessed factors that influence households’ access to improved water sources in both rainy and dry seasons, likewise the impacts of land use and land cover on water quality. Water quality at intake and point of consumption was also determined as well as seasonal variation. The quality of water was evaluated by applying Canadian Council of Ministers of the Environment Water Quality Index model (CCME WQI). Non-carcinogenic risk associated with chemical exposure was achieved based on the estimation of hazard quotient and hazard index and quantitative microbial risk assessment (QMRA), which was used to estimate the disease burden and risk of infection due to microbial contamination of water. Geospatial analysis and techniques enable us to measure and estimate water quality, and the population at risk and visualize it over a space using Geographic Information System. The study found that households’ access to improved water sources significantly improved from 81.67% in the dry season to 90.83% in the rainy season (p<0.0012). In both survey seasons, compared to residents in non-mining communities, residents in mining communities were less likely to have access to improved water sources. At higher temperatures 27.79-27.98, households had lower odds of having access to improved water sources in the dry season. According to the Land use/Land cover map, there was a significant decrease in water levels during the dry season. The analysis conducted on the median difference in water quality parameters among water sources and households revealed significant deterioration in some water quality parameters in households. Total Coliform was higher in the households compared to the main sources (z = -2.337, p = 0.0195), Faecal Enterococci (z = -2.100, p = 0.0357), and E. coli (z = -2.907, p = 0.0037) were also higher in the households compared to the main source. Seasonal variation of water pollutants revealed a strong negative impact of rains on microbiological contaminants. Total coliform decreased in the dry season (Z=3.379, p=0.0007), Faecal Enterococci deteriorated during the rainy season (Z = 4.270, p = 0.0000), There was higher in E. coli, Salmonella and Shigella during the rainy season respectively (Z= 5.410, p = 0.0000, Z= 3.602. P= 0.0003 and Z= 3.726, p= 0.0002). The study revealed some physico-chemical and metals having lower concentrations during the rainy season than the dry season. pH levels tend to be higher in the dry season compared to the rainy season (Z = -2.220, p = 0.0264). Temperature was also higher during the dry season than the rainy season (Z= -9.223, P= 0.0000). TDS of the water was significantly lower in the rainy season (Z = -2.133, p = 0.0329). Sanitary inspection conducted at the main source and household showed that most boreholes and other water sources were installed near source of pollution with the majority of the pumps damaged at the point of attachment. Most of the households’ sanitary practices were not in accordance with UNICEF and WHO guidelines. The risk priority matrix showed that in the rainy season, 64% of the water points analyzed had a very high risk of Total Coliform contamination based on the established threshold by WHO. For the dry season, bacteriological testing revealed that 34% of the sites had counts greater than 100 CFU/10mL, 42% had Total Coliform counts between 11 and 100 CFU/100mL and 12% had low risk. The study found that arsenic levels in water samples pose a significant carcinogenic risk to residents, with 16% below detection limits, 14% within optimal range, 70% above thresholds during the rainy season, and 60% below detection limits, with 8% within the optimum range and 32% above the threshold during the dry season. The hazard index (HI) for As, Hg, and F- varied during the rainy and dry seasons. The target organ for these ions is the kidney, with 16% of sample points exceeding the safe limit. For Arsenic and Nitrate, targeting the liver, 10% of points were above the safe limit, while 2% were recorded in the rainy season. QMRA on the other hand indicated significant differences in the diseases burden arising from the various sources of water. A major part of the annual risk of infection originated from Shigella (9.89 X 10-1) was from the household and the least important contributor was E. coli at the main source. The majority of the water points had disease burden higher than the reference standard set by WHO of (10-6). The water quality map showed areas with good to excellent water quality for human consumption. During the rainy season, western parts like Balungu and Shia have marginal water quality, while eastern parts like Gbane Kejetia and Gbane Obuasi have marginal water quality. In the dry season, most eastern water points improve, while western Balungu has marginal water quality. The study identified areas with groundwater fluoride levels exceeding 1.5 mg/L, affecting the population relying on groundwater for daily needs. The north-western (Shia) part of the district was at high risk, with fluoride levels above WHO reference standards during both survey seasons. A total of 438 children between the ages of 0-15 years were at risk as a results of Fluoride exposure during the dry season while 516 children were at risk during the rainy season. An estimated of 1950 people were potentially exposed during the dry season and 2012 during the rainy season.