What do you call a covered pit where septic tank effluent is received and leaches into the soil?

The correct term for a covered pit where septic tank effluent is received and leaches into the soil is a seepage pit. A seepage pit is specifically designed to receive and manage the effluent from a septic system, allowing it to gradually dissipate into the surrounding soil. This method of effluent disposal is essential in managing wastewater from septic tanks when a drain field may not be feasible due to site constraints or soil conditions.

The other terms do not accurately describe this particular function: a seepage well typically refers to a structure that allows water to enter from the surface for groundwater recharge but does not specifically pertain to septic effluent management. A drain field, while related to septic systems, consists of a series of trenches or beds where effluent is distributed for absorption into the soil, rather than a single covered pit. An effluent pit would suggest a storage or holding area rather than a leaching system, misrepresenting the function of the seepage pit. Each term has its own specific definition and use in plumbing and wastewater management, but in this instance, seepage pit is the appropriate designation for the concept described.