Current Status of Groundwater Pollution

Nitrate/nitrite nitrogen were added to “Monitored ItemsE in 1993 and since then it has been monitored officially. In February 1999, the Environmental Quality Standards for Groundwater Pollution was set for nitrate/nitrite nitrogen (Environmental Standard Value: not less than 10 mg/L as the total of nitrite/nitrate nitrogen).

MOE and local governments have been monitoring these substances since 1999 under the framework of Water Pollution Control Law and have found that they have exceeded the environmental standard value to a greater extent than other target substances.

Figure Changes in Rate of Wells Exceeding the EQSs (Survey to grasp the overall condition of the local groundwater)

Notes:
1.Different wells were surveyed in the general monitoring survey every year.
2.The environmental quality standards (EQSs) for groundwater were established in FY 1997. Assessment standards were used before the establishment of the EQSs. (The assessment standard for arsenic was revised from "0.05mg/L or less" to"0.01 mg/L or less.")
3.Nitrate-N/nitrite-N, fluorine and boron were added to the list of substances for which EQSs shall be set in 1999.