The Aqua Tepula is an ancient Roman aqueduct built in 126 BC by censors G. Servilius Caepio and L. Cassius Longinus. Its source was at the Alban hills, running only a mere 18 kilometers to Rome. The water from the Aqua Tepula, as implied in the name, was tepid and lukewarm, and thus was, as Frontinus states, not fit for human consumption.
The Aqua Tepula's waters were, as stated by Frontinus, lukewarm. In 33 BC, M. Viscus Agrippa attempted to cool its waters by mixing the Aqua Tepula's waters with that of a recent aqueduct, the Aqua Marcia. The water was mixed in a clearing basin then was split into two separate lines that reached their separate terminus. Superimposed on the Marcia, the Tepula was the highest aqueduct, and thus able to deliver water over many parts. However, the cost of the Marcia and the poor quality of water stemmed its could-have-been success. The smallest aqueduct, it delivered 17,800 cubic meters per day, a scant amount in Roman times.