This technical note describes each step in constructing an aqua privy. An aqua privy is an underground watertight vault filled with water that receives excreta and wash water from a drop-pipe, allows solids to settle to the bottom, and discharges effluent to a soakage pit. Constructing an aqua privy involves excavating two pits, building a vault from concrete or brick and mortar, installing a concrete slab with a drop-pipe and a vent pipe, laying sewer pipe from the vault to the soakage pit, and building a soakage pit. Read the entire technical note before beginning construction.