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When Mexico and the United States signed the North American Free Trade Agreement 20 years ago, the goal was to increase commerce and boost both countries' economies. The treaty included an environmental component, as well. Both countries are supposed to be cleaning up the Rio Grande, the river that makes up a large chunk of the border. But despite some progress, massive amounts of raw sewage still enter the water each day.
Reporter Neena Satija, of the Texas Tribune reports.
NEENA SATIJA, BYLINE: There's one way to find out how bad the water quality is in the Rio Grande: get into a kayak.
(SOUNDBITE OF PADDLING)
SATIJA: Oh, here we go. You can smell it, right?
TOM VAUGHAN: Oh, yeah.
SATIJA: That's Tom Vaughan, who teaches biology at Texas A&M International University. As we paddle through chocolate-brown water in Laredo, the overwhelming smell makes it hard to breathe. A dog's carcass floats by and there are many dead fish, too. In a kayak next to mine is Mike Montemayor, commissioner of Webb County, Texas.
So what do you think, Commissioner?
MIKE MONTEMAYOR: I think it's a mess. Yeah. It's horrible.
SATIJA: Vaughan has studied water quality in the Rio Grande for decades. The levels of E. coli bacteria here, he says, are way off the charts. Federal regulations allow swimming and fishing in water that has a miniscule amount of E. coli.
VAUGHAN: And certainly, what we're in right now, the E. coli's in the thousands.
SATIJA: Normally, the Environmental Protection Agency would get involved in a water quality issue like this one. But the Rio Grande is unique because it straddles two countries. And this raw sewage comes from Mexico, in Nuevo Laredo. So that puts this guy in charge.
ADOLFO MATA: My name is Adolfo Mata, and I'm the program manager for the Laredo field office of the U.S. section of the International Boundary and Water Commission.
SATIJA: The International Boundary and Water Commission is a part of the U.S. State Department that works with neighboring countries, like Mexico, on boundary issues. Mata says 20 years ago, Nuevo Laredo didn't treat any of its sewage. The Rio Grande was so dirty people actually died from swimming in it.
MATA: There was not a wastewater treatment plant in Nuevo Laredo until 1996. But in the early 1990s, both the U.S. and the Mexican government and the state of Texas pooled the resources together to build an international wastewater treatment plant.
SATIJA: The $60 million plant has made a huge difference. But every day, at least 5 million gallons of raw sewage enters the water. Many parts of Nuevo Laredo still aren't connected to the sewer system and some pipes need repairs. Mata said he often meets with his Mexican counterpart to work on solutions, but that's not happening fast enough for some Texas towns.
AMANDA PEREZ: My 3-year-old, he started the tummy ache.
SATIJA: That's Amanda Perez, who also was on the kayak tour down the river. She's commissioner of the town of Rio Bravo in Texas.
PEREZ: Then it was a coincidence because whenever we would go to the doctor, it wouldn't be me. It would be a lot of kids, and I thought, oh, my God, it's an epidemic, or what's going on?
SATIJA: Cleaning this dirty water is really expensive, and Rio Bravo's water treatment plant can't keep up. The water in the town tested positive for E. coli recently, and for almost a month, thousands of residents in the region were told to boil their tap water. But even though the boil order has been lifted, Perez won't even give tap water to her dog.
PEREZ: Oh, wow. I'd - we had - I had no idea that this was so, so terrible and so dangerous to our environment and to our water. And I don't have words to explain. I can't - I did not believe it was that bad.
SATIJA: Environmentalists say in the wake of NAFTA 20 years ago, the U.S. and Mexico had the political will to start cleaning up the Rio Grande. The question now is whether there's momentum to finish the job. For NPR News, I'm Neena Satija.