On the basis of groundwater flow model in the suburbs,the paper built the solute transport model of the third plant of water source in the western suburbs by generalizing the model.It calculated the maximum allowa ble emissions of the acceptable typical pollutants within a certain period by using the couple of SCE algorithm with the solute transport model. The result indicated that under the circumstance of water quality being no more than the class III water standard within twenty years, the maximum annual emissions of NO-3 and Cl- of landfills in the north of Tiancun, Xirancun, and the east of Beiwucun in the protected area of the third plant of water source are as follows, the density of NO-3, the east of Beiwucun is 18.59t/a, the north of Tiancun is 42.29t/a, Xirancun is 21.45t/a; and the density of Cl-, the east of Beiwucun is 235.66t/a, the north of Tiancun is 441.13t/a, Xirancun is 290.13t/a.The result can provide the basis for the establishment of water pollution early-warning system and the protection of water source.