Ancient Romans knew that lead water pipes were unhealthy and so they preferred terracotta pipes. It's hard to imagine why the U.S. ever had a single lead water pipe, let alone huge numbers of them.
Updated with a reference for the downvoters:
Sheets of lead were used to line Roman aqueducts (as was cement) and lead pipes to convey water. But lead also was known to be unwholesome and, for that reason, pipes made of clay were preferred—as Vitruvius, who wrote during the time of Augustus, explains.
"Water conducted through earthen pipes is more wholesome than that through lead; indeed that conveyed in lead must be injurious, because from it white lead [ceruse or lead carbonate, PbCO3] is obtained, and this is said to be injurious to the human system. Hence, if what is generated from it is pernicious, there can be no doubt that itself cannot be a wholesome body. This may be verified by observing the workers in lead, who are of a pallid colour; for in casting lead, the fumes from it fixing on the different members, and daily burning them, destroy the vigour of the blood; water should therefore on no account be conducted in leaden pipes if we are desirous that it should be wholesome. That the flavour of that conveyed in earthen pipes is better, is shewn at our daily meals, for all those whose tables are furnished with silver vessels, nevertheless use those made of earth, from the purity of the flavour being preserved in them" (VIII.6.10-11).
http://penelope.uchicago.edu/~grout/encyclopaedia_romana/win...
Updated with a reference for the downvoters:
Sheets of lead were used to line Roman aqueducts (as was cement) and lead pipes to convey water. But lead also was known to be unwholesome and, for that reason, pipes made of clay were preferred—as Vitruvius, who wrote during the time of Augustus, explains.
"Water conducted through earthen pipes is more wholesome than that through lead; indeed that conveyed in lead must be injurious, because from it white lead [ceruse or lead carbonate, PbCO3] is obtained, and this is said to be injurious to the human system. Hence, if what is generated from it is pernicious, there can be no doubt that itself cannot be a wholesome body. This may be verified by observing the workers in lead, who are of a pallid colour; for in casting lead, the fumes from it fixing on the different members, and daily burning them, destroy the vigour of the blood; water should therefore on no account be conducted in leaden pipes if we are desirous that it should be wholesome. That the flavour of that conveyed in earthen pipes is better, is shewn at our daily meals, for all those whose tables are furnished with silver vessels, nevertheless use those made of earth, from the purity of the flavour being preserved in them" (VIII.6.10-11).
http://penelope.uchicago.edu/~grout/encyclopaedia_romana/win...