America is due for new pipes, aqueducts and water mains, and the public is probably going to pay for it. Aging water systems will need a repair — either by prudent maintenance or in response to water main breaks — and utilities will have to pass the costs on to consumers. Exactly how much and where is the question answered by a paper published in PLOS One. The Environmental Protection Agency says that an “unaffordable” water bill is one that exceeds 4.5 percent of a household’s income. Now, about 12 percent of Americans have water bills at that level.