The wastewater is used for irrigating subsistence crops, and its many pathogens end up on the food locals eat to survive.

In a room above the Shady Oak Gallery in Micanopy, a pair of scientists are devising how to change the world of wastewater management — one stream at a time.
Terry Griffith, 55, a civil and environmental engineer who spent most of his career at the Environmental Protection Agency, and Janna Owens, 56, an aquatic biologist from Alabama, established a nongovernmental organization called the Chaac water group — named for a Mayan water goddess. It aims to improve the wastewater management in Mexico.
They’ve focused most of their efforts on the water outside of San Miguel de Allende, a city about the size of Gainesville in the north central highlands of Mexico. The town center, with buildings from the 17th and 18th centuries, and the nearby Sanctuary of Atotonilco, known as Mexico’s Sistine Chapel, are both UNESCO World Heritage Sites.
But the wastewater in both places, which in its simplest form occurs every time someone flushes a toilet, is polluting the water around the city. Especially concerning is that the wastewater is used for irrigating subsistence crops, and its many pathogens end up on the food that locals are eating to survive.
While some byproducts of the wastewater, such as nitrogen and phosphorus, are good for the crops, the pathogens in the water spread diseases such as typhus, cholera and helminthiasis, a condition spread by the eggs of helminth worms, Owens said.
Owens actually contracted helminthiasis herself in Mexico and said that’s partly why she and Griffith were so inspired to improve the situation around the city.
“That part of Mexico is suffering from the perfect storm,” Owens said, adding that it’s the “bread basket” for crops exported to the U.S. Because the USDA prohibits imports from being grown with wastewater, 70 percent of the well-water crops leave Mexico, and local farmers are unable to build wells.
So they irrigate with wastewater instead. The water has tested positive for the E. coli bacteria, which is usually indicative of other pathogens, Owens said.
“If E. coli is there, everyone else is at the party,” she said, referring to other pathogens.
The city’s existing water treatment facility treats only about one-third of the water, and most of it is diverted to a golf course, Griffith added.
“The rest goes into the fields, streams and reservoir,” and this affects both farmers and fishermen, he said.
While Owens was measuring water quality, Griffith measured water flow levels in streams, canals and pipes to see how much wastewater was filling the reservoir.
Griffith initially undertook the project as a Peace Corps volunteer two years ago. Owens accompanied him as a “rogue biologist,” she said, and knocked on the doors of various NGOs and agencies locally asking if they needed a biologist.
The duo, who met at an EPA course seven years ago and share the same birthday, are known in San Miguel de Allende as “the river doctors without borders.”
“The tall, lanky Americans with backpacks” ambling through the town is how Owens describes them.
They’ve worked with several local groups in San Miguel de Allende, and some of their research was sponsored by the National Audubon Society. The idea now is to come up with a blueprint together to help curb wastewater irrigation.
“We’re trying to work together to empower them to solve the problem,” Griffith said.
This could be as simple as signage identifying heavily polluted no-go zones for kayaking tourists and fishermen, as well as a more ambitious plan to create lagoons, where the harmful components of wastewater would break down over time, Griffith explained.
“This is not isolated,” he added. “There’s hardly a clean stream anywhere in the Central Highland area (of Mexico).”
Owens added that the largest irrigated field in Mexico is in the Mezquital Valley at 2,700 square miles, and it is irrigated with wastewater from Mexico City, 37 miles to the south.
The team anticipates traveling back to Mexico the early part of next year.
For now, they are enjoying Micanopy, their home of five years when they aren’t traveling.
Gainesville was on a list of places in the U.S. that appealed to them, mostly because it’s a college town.
“We were roaming around Gainesville, and an older couple on their bicycles told us to go to Micanopy,” Owens said. “On New Year’s Eve, we had dinner in Micanopy while the sun was setting, and we loved it.”
Kristine Crane writes for the Gainesville Sun.