Ancient Maya in the city of Tikal built an advanced water filter system that could remove microbes and heavy metals, 2,000 years before such systems were used in Europe.
Researchers found natural minerals that had been imported from miles away and were used to create a molecular ‘sieve’ to purify water.
Kenneth Barnett Tankersley, of the University of Cincinnati, said: “What’s interesting is this system would still be effective today and the Maya discovered it more than 2,000 years ago.
“The ancient Maya lived in a tropical environment and had to be innovators. This is a remarkable innovation.
“A lot of people look at Native Americans in the Western Hemisphere as not having the same engineering or technological muscle of places like Greece, Rome, India or China.
“But when it comes to water management, the Maya were millennia ahead.”
The ruins of Tikal in Guatemala were abandoned more than a thousand years ago, and were rediscovered by a gum sapper in 1853.
The city flourished between 300 and 850AD, and was known to the Maya as Mutul.
UC researchers discovered evidence of a filter system at the Corriental reservoir, an important source of drinking water for the ancient Maya in what is now northern Guatemala.
Their findings were published in the journal Scientific Reports.
Ancient Maya in the once-bustling city of Tikal built sophisticated water filters using natural materials crystalline quartz and zeolite, scientists said.
Researchers from UC's College of Arts and Sciences traced the minerals to steep ridges around the Bajo de Azúcar, about 18 miles northeast of Tikal.
They used X-ray diffraction analysis to identify zeolite and crystalline quartz in the reservoir sediments.
For the ancient Maya, finding ways to collect and store clean water was of critical importance. Tikal and other Maya cities were built atop porous limestone that made ready access to drinking water difficult to obtain for much of the year during seasonal droughts.
UC geography professor and co-author Nicholas Dunning, who has studied ancient civilisations most of his career, found a likely source of the quartz and zeolite about 10 years ago while conducting fieldwork in Guatemala.
“It was an exposed, weathered volcanic tuff of quartz grains and zeolite. It was bleeding water at a good rate,” he said.
“Workers refilled their water bottles with it. It was locally famous for how clean and sweet the water was.”
Dunning took samples of the material. UC researchers later determined the quartz and zeolite closely matched the minerals found at Tikal.
“It was probably through very clever empirical observation that the ancient Maya saw this particular material was associated with clean water and made some effort to carry it back,” Dunning said.
Of course, reconstructing the lives, habits and motivations of a civilisation 1,000 years ago is tricky.
Dunning said: “We don't have absolute proof, but we have strong circumstantial evidence. Our explanation makes logical sense.”
Watch: Archaeologists in Mexico find first Mayan slave ship