Abstract
The 2nd method Parfait-Hounsinou makes it possible to note the physico-chemical quality and the microbiological quality of water by two alphabetical letters representing respectively the Chemical Water Quality Index (CWQI) and the Microbiological Water Quality Index (MWQI). The steps of using this method are the measurement of the physico-chemical and microbiological parameters of the water samples, the calculation of the CWQI and MWQI, the deduction of the overall quality of the water samples and the construction and then the study of the 2nd Parfait-Hounsinou diagram which is 2 particulars diagrams of Spie chart use to show the detailed chemical quality of the water samples. We applied this method to the groundwater of the municipality of Abomey-Calavi in Benin and then we compared this method to the water quality assessment methods that are often the most used. The novelty of the 2nd method Parfait-Hounsinou is that it makes it possible to evaluate the global quality of water in a uniform way all over the world, in particular whatever the influence of temperature on the pH of the water. •The 2nd method Parfait-Hounsinou makes it possible to attribute to a water sample a score which characterizes all its physico-chemical and microbiological parameters.•Researchers, WHO and governments around the world can use the 2nd method Parfait-Hounsinou to monitor changes in the quality of water resources around the world.•The meanings of the scores assigned to water samples using the 2nd method Parfait-Hounsinou are easily understood and useful by journalists and the general public.