Annalee Newitz wrote an awesome piece for Ars Technica on a subject that most people would probably not care much about: Ancient Rome’s plumbing and sewage system:

The ancient Roman plumbing system was a legendary achievement in civil engineering, bringing fresh water to urbanites from hundreds of kilometers away. Wealthy Romans had hot and cold running water, as well as a sewage system that whisked waste away. Then, about 2,200 years ago, the waterworks got an upgrade: the discovery of lead pipes (called fistulae in Latin) meant the entire system could be expanded dramatically. The city’s infatuation with lead pipes led to the popular (and disputed) theory that Rome fell due to lead poisoning. Now, a new study reveals that the city’s lead plumbing infrastructure was at its biggest and most complicated during the centuries leading up to the empire’s peak.

Hugo Delile, an archaeologist with France’s National Center for Scientific Research, worked with a team to analyze lead content in 12-meter soil cores taken from Rome’s two harbors: the ancient Ostia (now 3km inland) and the artificially created Portus. In a recent paper for Proceedings of the National Academy of Sciences, the researchers explain how water gushing through Rome’s pipes picked up lead particles. Runoff from Rome’s plumbing system was dumped into the Tiber River, whose waters passed through both harbors. But the lead particles quickly sank in the less turbulent harbor waters, so Delile and his team hypothesized that depositional layers of lead in the soil cores would correlate to a more extensive network of lead pipes.

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The very existence of the pipe system was a sign of Rome’s fantastic wealth and power. Most lead in Rome came from distant colonies in today’s France, Germany, England, and Spain, which meant the Empire needed an extensive trade network to build out its water infrastructure. Plus, the cost of maintenance was huge. All pipes were recycled, but the city still had to repair underground leaks, check water source quality, and prevent the massive aqueducts from crumbling. In the first century CE, Roman water commissioner Julius Frontinus wrote a two-volume treatise for the emperor on the city’s water system, including a discussion of how to prevent rampant water piracy, in which people would tap the aqueducts illegally for agricultural use—or just for drinking.

What is fascinating to me is how researchers were able to correlate the economic status of Rome at different historical periods with the quality of the water and sewage infrastructure. The fact that such an infrastructure even existed over 2,000 years ago is astonishing enough.