Piscina
A small sink, basin, or niche that empties into the earth instead of a sewer. It is typically located in the sacristy or in the wall of the sanctuary. It may be used for the reverent disposal of consecrated wine from the eucharist, blessed water from baptism, and water used in washing vessels that have been used for a sacred purpose.
Glossary definitions provided courtesy of Church Publishing Incorporated, New York, NY,(All Rights reserved) from “An Episcopal Dictionary of the Church, A User Friendly Reference for Episcopalians,” Don S. Armentrout and Robert Boak Slocum, editors.