What are rock-filled pits dug at least 4 feet deep at the end of a septic tank absorption field called?

Rock-filled pits dug at least 4 feet deep at the end of a septic tank absorption field are known as seepage pits. They serve as a means to facilitate the infiltration of effluent from a septic system. The design of these pits allows for effluent to seep out of the sides and bottom, promoting the natural process of soil filtration and treatment before the effluent reaches the groundwater.

Seepage pits are beneficial in situations where soil conditions might not be adequate to accept the effluent from a traditional absorption field. By providing additional storage and a larger area for effluent to percolate through, these pits can help mitigate potential issues with septic system performance.

Cesspools, drain fields, and absorption trenches represent different types of wastewater treatment technologies but have distinct characteristics that differentiate them from seepage pits. Cesspools typically collect wastewater without filtration, leading to potential groundwater contamination. Drain fields are specifically designed for distribution of effluent across a broader area with specific design specifications, while absorption trenches utilize a linear trench system with gravel or other materials to enhance effluent absorption. Each of these systems serves particular functions within septic systems, but seepage pits are specifically identifiable by their depth and rock-filled construction intended for enhanced absorption capabilities.