Seepage pit explained

Question: I am building a new home and was told that my septic system needs to use a seepage pit rather than a leaching field. Can you explain what a seepage pit is and why it's necessary?

Answer: A seepage pit is used instead of a leaching field in residential sewage disposal when the lot the house is located on is too steeply sloped to allow building a field. The pit allows effluent to percolate into the ground the way a leaching field does, but it takes up less surface area. Sewage leaving a house settles in a septic tank before it flows into the pit.

The pit's bottom should be filled with 6 to 12 inches of coarse gravel, and the space between the pit liner and the surrounding soil with 3 to 6 inches of coarse gravel. The specific amount of gravel depends on local codes.

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