Present-day water-supply systems use a network of high-pressure pumps , and pipes in buildings are now made of copper , brass , plastic ( particularly cross-linked polyethylene called PEX , which is estimated to be used in 60 % of single-family homes ) , or other nontoxic material .
Today , water-supply systems use a network of high-pressure pumps , and pipes are now made of copper , brass , plastic , or other nontoxic material .