Although lead water pipes were displaced by copper when the significance of lead poisoning began to be fully appreciated, lead solder was still used until the 1980s because it was thought that the amount of lead that could leach into water from the solder was negligible from a properly soldered joint.
32.
From the " castellum " water was carried, now pressurized, in a set of airtight lead pipes laid side by side, with soldered joints, down the valley slope, across a bridge spanning the river whose piers and arches are the most notable remains of the system and up the facing slope, to a tank slightly lower than the head tank, losing just a little hydraulic head in the process.
