December 20, 2005
The Ministry of the Environment (MOE) announced the results of groundwater quality monitoring conducted by the national and local governments in FY 2004 pursuant to the Water Pollution Control Law. The Law provides that the governor of a prefecture shall monitor the quality of groundwater in accordance with the groundwater quality monitoring program prepared annually by each prefecture.
|1.||Number of municipalities and wells surveyed|
|2.||Result of general monitoring survey|
Among the substances most commonly found to exceed the EQSs, nitrate nitrogen and nitrite nitrogen have the highest ratio, 5.5% (6.5% in FY 2002), followed by arsenic, fluoride and tetrachloroethylene. For other 13 substances including cadmium, no wells are found exceeding the EQSs.
When a well is found to be polluted, whether it is supplying drinking water or not, in order to prevent health damages, the local government provides guidance for drinking (usage) to well users including the shift to water supply sources.
|3.||Number of municipalities in which wells exceeding EQSs are existing|
|4.||Chemicals of which the EQS exceeding rate is higher|
Nitrate nitrogen and nitrite nitrogen is designated as one of the monitoring items in 1993, and added to the list of substances for which EQSs are set in 1999. Compared to the other items, their EQS exceeding rate has been higher, and approximately 200 wells are found to be exceeding EQS. Fig. 3 shows that the pollution has become explicit, since the number of wells surveyed and those exceeding the EQS revealed by regular monitoring survey conducted to the wells that had been found contaminated by the previous year have increased.