The city of Tikal
purified one of its reservoirs with technology comparable to modern
The Maya built the Corriental
reservoir filtration system as early as 2,185 years ago. (szeke
via Flickr under CC BY-NC-SA 2.0)
More than 2,000 years ago, the Maya built a complex water filtration
system out of materials collected miles away. Now, reports Michelle
Starr for Science
Alert, researchers conducting excavations at the ancient
city of Tikal
in northern Guatemala have discovered traces of this millennia-old
As detailed in the journal Scientific
Reports, the study's authors found that the Maya built the
Corriental reservoir filtration system as early as 2,185 years ago,
not long after settlement of Tikal began around 300 B.C.
The systemwhich relied on crystalline quartz and zeolite,
a compound of silicon and aluminum, to create what the researchers
call a "molecular sieve" capable of removing harmful microbes, heavy
metals and other pollutantsremained in use until the city's
abandonment around 1100. Today, the same minerals are used in modern
water filtration systems.
"What's interesting is this system would still be effective today
and the Maya discovered it more than 2,000 years ago," says lead
Barnett Tankersley, an archaeologist at the University of Cincinnati,
in a statement.
According to Science Alert, archaeologists previously thought
that the first use of zeolite for water filtration dated to the
early 20th century. Researchers have documented other types of water
systemsincluding ones centered on sand, gravel, plants and
clothused in Egypt, Greece and South Asia as early as the
15th century B.C.
"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," says Tankersley. "But when it
comes to water management, the Maya were millennia ahead."
Per the statement, water quality would have been a major concern
for the ancient Maya, as Tikal and other cities across the empire
were built on porous limestone that left little water available
during seasonal droughts. Without a purification system, drinking
from the Corriental reservoir would have made people sick due to
the presence of cyanobacteria and similarly toxic substances.
The Tikal filtration
system used quartz and zeolite to remove both heavy metals
and biological contaminants. (Kenneth Barnett Tankersley /
University of Cincinnati)
Members of the research team previously
found that other reservoirs in the area were polluted with mercury,
possibly from pigment the Maya used on walls and in burials. As
Kiona N. Smith reported for Ars
Technica in June, drinking and cooking water for Tikal's
elite appear to have come from two sources that contained high levels
of mercury: the Palace and Temple Reservoirs. Comparatively, the
new research shows that Corriental was free of contamination.
The researchers write that the Maya probably found the quartz and
zeolite about 18 miles northeast of the city, around the Bajo de
Azúcar, where the materials naturally purified the water.
"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," says co-author
P. Dunning, a geographer at the University of Cincinnati, in
the statement. "They had settling tanks where the water would be
flowing toward the reservoir before entering the reservoir. The
water probably looked cleaner and probably tasted better, too."
Tikal, known as Yax Mutal to its ancient inhabitants, consisted
of more than 3,000 structures. At its height in 750, it was home
to at least 60,000 people, as David Roberts reported for Smithsonian
magazine in 2005. After its abandonment 900 years ago, much
of the city was lost until the late 20th century, when Guatemalan
archaeologists excavated what's known as the Lost
World, a complex of pyramids and buildings that had long been
hidden in the jungle.
Researchers have found written records that provide a complete
chronology of the Tikal's rulers over an 800-year period. In 1979,
Unesco designated Tikal
National Park as a World Heritage site, citing its well-preserved
structures and art, which attest to the development of Maya culture
The newly discovered filtration system adds to researchers' understanding
of Maya scientific achievements. Next, says Tankersley, he wants
to look for other Maya sites that may have used the same water purification