Abstract
The magnitude-6.9 Noto Hanto Earthquake struck at 9:41 a.m. 25th March 2007, off the north coast of Ishikawa Prefecture. The quake started under the ocean about 30 km southwest of Wajima, shaking up Ishikawa, Toyama and Niigata prefectures and cutting electricity and drinking water system to some 160,000 households, killing one person and damaging hundreds of houses. The quake also crippled public transportation, including Noto airport, and cut water to about 9,500 households. All residents, especially those who are near the hardest-hit area, are advised to use drinking water collected from spring, well and mountain natural water with extra caution, because the water got become muddy in white, gray, and brown color after the quake. Some of water changed to acidic pH 5.4-5.9 from neutral pH is not drinkable due to SO4. The legal standard of pH for drinking water is pH 5.8-8.6. The water contained 5-10 times of SO4 higher than standard concentration of SO4, but looking transparent after one week. The field measurements of water pH suggest that high SO4 contents are due to acidic drinking water, agreed with XRF, ion-chromatography, and SEM-EDX analyses. After 3 weeks, water pH 5.9 backed to the normal pH 6.5, but NO3, Ca and Mg contents were still higher than before the quake. We have ordered the government to work, toward securing the citizen's safety and take all possible measures of drinking water to rescue them. The health center office must take care of spring water, well, and mountain natural water to check pH as soon as possible associated with CPU (Colony Forming Unit) check.
