The river doctors are giving our water bodies a physical, but they could use some help
By George James
It’s called a ‘body’ of water for a reason. Like any other man-made or natural lake, the Presa Allende just west of our city is a living thing, responsive to its environment. Its health relies heavily on what it’s ‘fed’; the streams or rivers that flow into it, and the water that runs into it from the surrounding landscape during rainstorms.
If that water is clean and healthy, so will be the lake or reservoir it feeds—as well as the fish that swim in it, the birds and amphibians that live around its banks and other wildlife that count on its presence. And so will be the humans that use it or its water.
But like any other living body, the Presa that graces sunset views from San Miguel also suffers from the poisons or pathogens it’s fed. When untreated sewage or toxic chemicals, like those contained in waste motor oil, flow into its water, the health of the whole ecosystem that depends on the lake’s condition—including farms and communities downstream—suffers.
That’s why the three water health specialists visiting San Miguel de Allende with the help of several local groups, have been testing the Presa’s water regularly over the past several weeks. It’s also why they need some willing assistant river doctors to keep the monitoring going as volunteer Citizen Observers and Monitors after the end of their stay here.
AguaVidaSMA and the Water Collaborative—a consortium of local water-focused citizens’ and volunteer groups including Audubon de México, Amigos de la Presa and Salvemos al Río Laja—invited US-based environmental consultants Janna Owens and Terry Griffith, partners in the Chaac Water Group, and Ina Lepore, a volunteer with UK-based Engineers Without Borders, to continue a survey of threats to the health of San Miguel’s water bodies begun last year.
It’s the ecological equivalent of giving the Presa Allende, and the two most important streams that flow into it, the Río Laja and the Arroyo Las Cachinches, which runs below the San Juan de Dios market, a basic physical. The tests reveal the condition of the sampled water in nine ways, from the amount of oxygen it contains to the presence of E.Coli bacteria.
Despite its bad name, the last of these usually isn’t the pathogen that most people think it is. But because it’s found only in the guts—and feces—of warm-blooded mammals, it’s a highly reliable indicator that other dangerous bacteria, viruses, parasites and protozoa probably are present as well.
Volunteers have already begun to test the health of water samples taken from 10 locations in the Presa Allende and Río Laja every month.
To give a reliable picture of how healthy our area’s surface water bodies really are, however, the same places need to be sampled regularly to create an accurate baseline estimate of what’s entering the Río, Arroyo and Presa.
Volunteer Citizens Observers will also keep an eye out for and document more visible threats to the health of the water bodies: pipes that discharge untreated liquids into the Rio or Arroyo, stream bank disturbances, trash, and unauthorized water withdrawals.
The first two months of observations have confirmed, and begun to measure, two such specific threats.
Untreated sewage, diverted from the SAPASMA sewer system, is entering the Arroyo Las Cachinches and Presa Allende from many places, producing “pervasive contamination” of their waters, the team has determined.
In particular, a walking survey along the south side of the Arroyo just west of the Libramiento de Dolores Hidalgo, revealed where a large sewer pipe, coming down the hill from the general direction of Misión de la Estancia, entered a concrete tank sunk into the ground. Liquid sewage flowed from the tank into a hand-dug canal that wound through reeds and trees in the direction of the Presa and the city wastewater treatment plant. The canal was found to feed several side channels where the sewage ran into fields in the area of the treatment plant; a source of free water and fertilizer, but also highly contaminated.
The discovery has prompted the team to identify a second serious threat to the health of nearby ejido residents and workers exposed to sewage water in the cultivated fields growing beans, corn, and feed corn. Considered one of the most prevalent but overlooked tropical diseases, infection by the parasitic helminth worm typically starts in the gastrointestinal tract but can spread to other major organs. Samples of untreated sewage water being used for irrigation revealed elevated levels of helminth eggs.
The team hopes to enlist additional Citizen Observers to conduct similar surveys along nine other stretches of the Arroyo, to locate and document other specific, active threats that need to be addressed.
Then it will be time for the river doctors to prescribe some cures to bring the city’s water bodies back to full health. Owens, Griffith and Lepore plan to develop and circulate to the public and interested stakeholders a list of seven alternatives for citizens and state and city authorities to consider. The various alternatives will be evaluated for their potential effectiveness, feasibility, sustainability, and their compliance with environmental needs and World Health Organization standards.
The team’s sponsor groups will also be seeking the public’s feedback and comments on the alternatives.
If you’d like to know more, sign up to receive the team’s forthcoming recommendations, or learn more about becoming a Citizen Observer, contact:firstname.lastname@example.org.
George James can be reached at email@example.com. He is a communications consultant and San Miguel resident who volunteers his time with water groups.