The given groundwater shows the following chemical composition: Sodium =7 mgIL, Calcium = 70 mg/L, Magnesium = 35 mg/L, Potassium = 1 mgIL Bicarbonate = 200 mg/L, Sulfate = 30 mgIL, pH = 7.5 Atomic mass unit: sodium (23), calcium (40), magnesium (24.3), potassium (39.1) Sulfur (32.1), hydrogen (1), oxygen (16), carbon (12) Can all calcium and magnesium in the groundwater, theoretically, be removed by internal alkalinity during the softening process? If not, how much calcium and or magnesium should be removed by the addition of external source of alkalinity? Show your work for the full credits.