Piscina

A piscina is a shallow basin placed near the altar of a church, or else in the vestry or sacristy, used for washing the communion vessels.

This sink has a cover, a basin, and a special pipe and drain that empty directly into the earth, rather than into the sewer system" (USCCB, Built of Living Stones, 236).

The piscina is a Latin word originally applied to a fish pond, and later used for natural or artificial pools for bathing, and also for a water tank or reservoir.

[3] Piscinae seem at first to have been mere cups or small basins, supported on perforated stems, placed close to the wall, and afterwards to have been recessed therein and covered with niche heads, which often contained shelves to serve as ambries.

They frequently take the form of a double niche, with a shaft between the arched heads, which are often filled with elaborate tracery.

Anyone, therefore, who acts contrary to these norms, for example casting the sacred species into the sacrarium or in an unworthy place or on the ground, incurs the penalties laid down.