The water quality criteria applied to streamwater and lakes classify public water into 5 categories and do not make differences on the use of water. Under present classification system, the level V water is not supposed to be usable for agricultural p...
The water quality criteria applied to streamwater and lakes classify public water into 5 categories and do not make differences on the use of water. Under present classification system, the level V water is not supposed to be usable for agricultural purposes, which is not true. It is proposed that water quality criteria for agricultural irrigation be separated from current classification system. The standards of BOD, COD, and TN should be set as critical value, that is the maximum concentration which do not harm the growth of rice. Field experiments are necessary to test the critical value of important water quality items.