Given below are two statements : Statement-I : If BOD is 4 ppm and dissolved oxygen is 8 ppm , then it is a good quality water. Statement-II : If the concentration of zinc and nitrate salts are 5 ppm each, then it can be a good quality water. In the light of the above statements, choose the most appropriate answer from the options given below :

Step-by-step solution

Drinking water has a BOD level of 1   -   2   ppm . When the BOD value of water is in the range 3   -   5   ppm , the water is moderately clean. Polluted water has a BOD value in the range of 6   -   9   ppm . Healthy water should generally have dissolved oxygen concentrations above 6 . 5 - 8   mg / L Drinking water with concentrations of nitrate (measured as nitrate-nitrogen) below 10   mg of nitrate per liter of water ( mg / L ) is considered safe. Permissibl