2. Booming business

There are about 300 companies along the Santiago River. Many of them are U.S. household names: multinational businesses like, Pepsi, Nestlé, and Hershey’s; chemical factories like Sanmina, Quimikao, and Huntsman, a supplier of dyes to a popular American jeans maker; and Celanese, which makes cigarette filters.

Information about the real state of Mexican waterways does exist, but it’s difficult to get hold of. After a lengthy legal battle with Greenpeace, the Jalisco State Water Commission released a damning study, with data from 2009 and 2010 showing the contaminated state of the river.

It found that factories are the main reason why more than 1,000 chemicals course through the Santiago River. Along with arsenic, factories dump large amounts of chrome, lead, zinc, mercury, toluene, phosphorus, and cyanide, as well as synthetic chemicals into the river.

Fusion Investigates has identified at least 26 U.S.-based companies operating in the area. At least 12 of them have discharged toxic waste into the river or its tributaries, according to publicly available information, Fusion Investigates has found. According to the government report, five of those U.S.-based companies have discharged chemical waste in excess of the law.

The same practices in the United States have led to fines in the past. In Mexico, though, enforcement of environmental regulation is lax at best.

3. Murky numbers

The system designed to measure the waste is riddled with possible conflicts of interest. Companies in Mexico contract private laboratories to analyze chemical discharge, and the companies then send a set of data to the National Water Commission. But often these laboratories are also contracted by the companies for other jobs simultaneously. Cindy McCulligh, a PhD candidate at Guadalajara’s Center for Advanced Studies in Social Anthropology, has studied the polluting of the river for the last decade. She says the regulatory system is flawed. “If I do an analysis of your discharge and you’re not in compliance, I am going to let you know before this goes off to the [National Water Commission],” she said.

Some of the reports obtained by Fusion Investigates, raise questions about their accuracy. One example is Sanmina, a Fortune 500 company. In it’s reporting -- the numbers for several categories looks curiously similar -- in many cases, it appears the only difference is where the decimal point is placed.

“It’s obviously a very rough calculation that I don’t think is based on any water quality analysis,” McCulligh said of the figures. Sanmina did not respond to questions regarding the surprising similarity of the numbers or their environmental practices.

The State Water Commission’s own research declared portions of the river a health hazard. Residents near some parts of the river and its tributaries are exposed to levels of heavy metals far in excess of the maximum environmental standard, including in the town where Lopez Rocha lived. The report concluded the contamination needed to be reversed “in the short term” because “the adverse consequences are already evident.” The waste produced by major factories clocked in well above Mexico’s federal limit on chemical discharge, according to the report.

4. The companies

Raúl Güitron Robles is president of the Industrial Association of El Salto (AISAC), -- the Mexican equivalent of a chamber of commerce. As head of the association, he said companies are concerned about the health of the El Salto community. But he has two jobs; Robles is also president of Quimikao, a company that has polluted the Santiago River. According to the State Water Commission report, Quimikao discharged grease and oils at a level 46 times above the legal limit. In the same report, tests showed the company dumped 52 times above the legal limit for suspended solids (indicators of water quality) and 13 times above the limit for nitrogen. When asked about exceeding the limits, Robles said he couldn't speak on behalf of the company, but he told Fusion Investigates it's the government's job to regulate. “The authorities should be the ones determining that, because they are the ones that set the parameters. They determine what sanctions are needed,” he said.

Robles didn’t refute the report’s findings. “We haven’t doubted their results and studies,” he told Fusion Investigates. But he was quick to defend the company’s more recent practices. “Quimikao is in compliance today, with the requirements set by the authority. Otherwise they would have taken action already,” he said.

Or maybe not.