By Amy Silverman
By Olivia LaVecchia
By Monica Alonzo and Stephen Lemons
By Chris Parker
By Michael Lacey
By Weston Phippen
The Mexican-American border is a virtual cesspool and breeding ground for infectious disease.
Nature respects geographic boundaries, not political ones.
Nogales Wash originates about 8.6 kilometers south of the Mexican-American border, fed by natural springs. The perennial wash travels north, through Nogales, Sonora, where it merges with storm flow and raw sewage, and crosses the border into Nogales, Arizona.
When Nogales Wash enters the United States, its water contains fecal coliform levels that are 12 million to 16 million times higher than U.S. drinking-water standards allow. The water is also contaminated with industrial by-products, including chlorinated solvents.
Chlorinated solvents--including trichloroethylene (TCE) and petrachlorethylene (PCE)--are highly toxic and depress the central nervous system. Many scientists believe they cause birth defects, cancer, and lupus, a chronic immune-system deficiency that damages the skin, joints, blood system and kidneys. Many others argue the link isn't so clear.
Nogales, Arizona, has the highest incidence of lupus ever recorded in the United States, and one of the highest rates of multiple myeloma, a rare bone cancer.
The population of Nogales, Arizona, is 20,000. There are, on average, 40 cases of cancer diagnosed there each month, five times the normal rate listed by the American Cancer Society.
Nogales Wash flows near 200 private drinking wells in Nogales, Arizona, several of which tap the aquifer directly. (After Nogales Wash flows through Nogales, Arizona, it joins Potrero Creek, which in turn flows into the Santa Cruz River just east of the Nogales International Wastewater Treatment Plant. There the water is treated before being dumped back into the Santa Cruz, which serves as a source for Tucson's public water supply.)
Alarmed by the cancer and lupus rates, Nogales citizens, many of whom were sick, formed LIFE (Living Is for Everyone) in 1992. The group examined death certificates for the 603 people who died in Nogales, Arizona, between 1986 and late 1992, and found that nearly half, 290, died of lupus or cancer.
Spurred by LIFE's findings, the University of Arizona and the Arizona Department of Health Services conducted a study in 1994 that confirmed that the rates of lupus and multiple myeloma in Nogales, Arizona, were four times above normal.
"There is strong evidence that adverse health effects have occurred in residents of Nogales, Arizona," the study concluded. "These health effects may be the result of complex environmental exposures to biologic or chemical agents."
The study called for more studies. That's been the theme on the border for almost a decade.
In 1990, the Border Ecology Project released data from a two-year series of water samples from wells along Nogales Wash in Sonora. (One of the wells was a source for a company that treated the water for fecal contamination, but not solvents, then sold it to maquila workers in squatter camps.) The tests found hazardous levels of multiple contaminants, including PCE and TCE.
"We were immediately accused of being hysterical and using phony data--even though we used Arizona Department of Health laboratories--and both governments procrastinated," says Dick Kamp, director of the Bisbee-based Border Ecology Project. "They didn't even go back and retest the wells."
Three years later, University of Arizona scientists released a study in conjunction with the Arizona Department of Environmental Quality that found that 24 percent of the population in Nogales, Sonora, drank contaminated water. The researchers tested 22 wells in Sonora and 13 in Arizona, and found chlorinated solvents and fecal bacteria in all of them. (The contamination on the Arizona side did not exceed health limits.)
In Sonora, solvent contamination was heaviest around three maquiladora parks in southern Nogales. The scientists also tested water in the sewers around the industrial parks, and reported the solvent content was so high it was difficult even to take the samples.
The most recent study of water in Nogales was released in June, and this time, it came from an official heavyweight--the International Boundary and Water Commission, a binational group of scientists from Mexico and the United States, funded by both governments.
The recent IBWC report revealed that several wells along Nogales Wash in Sonora--including one used for public drinking water until recently--were contaminated with PCE. Contamination in one well was extreme--140 parts per million of PCE (the U.S. standard for safe drinking water is 5 ppm, the Mexican standard is 8).
Seven wells on the Arizona side had no chlorinated solvents, although the scientists discovered high levels of arsenic and nitrates in two of them.
Water from a well ADEQ drilled in 1993 just south of the border at a point of constriction in the groundwater basin--a spot where most of the flow from Mexico passes--also exceeded both the U.S. and Mexican safe-water limits for PCE.
"The presence of these solvents in the Nogales Wash has been almost irrefutable for nine years," says Kamp. "It's a terrifying situation that this knowingly went on for so long, but it's also a typically political situation.
"Now that the governments have both checked for themselves, and come up with impeccable data that says we've got solvents in the groundwater, the next logical step is not to sit around and monitor the situation for another 10 years, but to react quickly.