Hello, What is the best way to keep my septic system from spreading out under my house, when there is very heavy and long time rains. The land slopes down. and the septic system (large pit) is 20 ft. in front of the house on the higher slope of ground. The septic system was put in on the highest part of the slope. because requirements would not allow the system closer that 75 ft. from the lake channel. Heavy rains causes a smell as if flows under the peir and beam house. Would a french drain in front of the house help? If so, how should it be built? Thanks Virgil Maners