Overview
- Researchers from the University of Mainz analyzed calcium‑carbonate deposits from Pompeii’s water system, with findings published in PNAS in January 2026.
- The deposits indicate bathwater in republican-era facilities contained bath oils, sweat and urine, pointing to very dirty conditions and likely high bacterial loads.
- Slave‑driven treadwheel pumps lifted only about 1,000 liters of fresh groundwater per day, often insufficient for even one complete daily water change.
- Later modernization, including the Serino aqueduct and new kettles and pipes, boosted water availability and warmth but introduced lead, zinc and copper into the system.
- Cyclical chemical patterns in the calcite may reflect fluctuating volcanic CO2 in groundwater before the 79 CE eruption, a tentative interpretation offered by the authors.