Aso is the world’s largest volcanic caldera.Five mountains dominate the center,and surrounded around the outer rim.Related to volcanic activity of Aso caldera formation,dates back to about 300,000 years ago, during the year and then about 200,000 repeated four times large eruption.The eruption was the explosion called pyroclastic flow, pumice and volcanic ash layer was discharged in large quantities and sediment, and comfortably cover in northern middle Kyusyu.Thick layer of volcanic ash layer is easy to form a stratum through the water, and be natural filters.That has resulted in groundwater of modern Japan to Aso.
In addition, water that has been setimated to be circulating in the earth is about km3 14 billion.In seawater is 97.5%.Fresh water can be used to human life is only 2.5%.And 2/3 of fresh water is present as ice in Antarctica and Arctic.About 0.8% exists as rivers and ground water.You can drink them as safe water is said to about 0.001%.You can say with water becomes more scarce good water.
Mainly shows the content of the mineral, bitterness, astringency, etc. is increased and a large amount, and that is included in the moderate, mellow flavor will be rich.
Is a major component of the mineral calcium and magnesium by means of the minutes, the mellow taste of the water will be lost and the lack of this.
Wed hardness is low, there is no habit, likes and dislikes will be high.
Shows the amount of organic matter with a bitter and often affects the consumption of chlorine and containing a large amount, gives the taste and mold odor in the water.
Refers to the dilution when diluted with water and odorless water to be measured was odorless.Drain odor or smell mold will be a particular problem.
There are three water of acidic, neutral or alkaline by its nature. The value of pH has a memory up to 0 to 14, also known as neutral point or chemically neutral 7.Will be more strong acid to be less than 7 , alkaline is great than 7.