(A) The first part of this paper demonstrates the feasibility of a DAF-filtration water treatment system for removal of humic substances and 400 color units from a contaminated water. Trihalomethanes are primarily formed by the reaction of free chlorine with humic substances, such as humic acid and fulvic acid, called trihalomethane precursors. A raw water containing 21.5 mg/L of humic acid, 400 units of color and 9 NTU of turbidity was treated by the continuous pilot plant. Over 94 percent of humic acid, 99 percent of color and 93 percent of turbidity were removed when 9.26 mg/L of alum in terms of Al2O3 was dosed as coagulant at pH 6.5. …….(B) The second part of this paper demonstrates the feasibility of the same DAF-filtration system skid-mounted on a boat for neutralization of acidity in lake water caused by acid rain. High acidity in lake water is primarily formed by dissolution of industrial air pollutants such as, sulfur dioxide (SO2), nitrogen oxides (NOx) , etc. which are carried by rains to lake water. Actual acidic lake water from Florida-MA having pH 4.9, color 3.5 units, turbidity 2.8 NTU, acidity 24 mg/L as CaCO3, nitrate nitrogen 0.4 mg/L, phosphate 0.1 mg/L as P, sulfate 70 mg/L and total coliforms 160 /100 mL was treated by the same pilot plant continuously for 5 hours under the same operational conditions but using 4.4 mg/L of sodium aluminate as Al2O3 and 3.5 mg/L of calcium hydroxide. It was discovered that DAF alone would be sufficient for acid rain neutralization, but the added filtration step would produce an effluent meeting the drinking water standards in terms of pH, color, turbidity, phosphorus, and coliforms.