(d) the following ions and substances are in concentrations lower than those indicated hereinafter in parts per million:(1) ammonia (as N): 0.5
(2) silver (as Ag): 0.05
(3) arsenic (as As): 0.01
(4) barium (as Ba): 1.0
(5) boron (as B): 5.0
(6) cadmium (as Cd): 0.01
(7) calcium (as Ca): 200
(8) chlorides (as C1): 250
(9) hexavalent chromium (as Cr): 0.05
(10) copper (as Cu): 1.0
(11) cyanides (as CN): 0.01
(12) iron (as Fe): 0.3
(13) fluorine (as F): 1.5
(14) magnesium (as Mg): 150
(15) manganese (as Mn): 0.05
(16) nitrates (as N) + Nitrites (as N): 10.0
(17) lead (as Pb): 0.05
(18) selenium (as Se): 0.01
(19) sulphates (as SO4): 500
(20) sulphides (as H2 S): 0.3
(21) uranyls (as UO2): 5.0
(22) zinc (as Zn): 5.0.