Signs bearing a skull and crossbones dot the banks of a reservoir and canal near this town on the U.S.-Mexico border, but the fishermen standing in the reeds nearby ignore them, casually reeling in fish that are contaminated with toxic chemicals and banned for human consumption.
Some do it to quell their hunger, others to make some cash by selling the carp, catfish and gar in nearby neighborhoods.
"It's a great little lake," says Joe Garcia, 43, among those fishing here one day recently, where a carp with the highest levels of toxic PCB chemicals ever tested in a fish was caught years ago. He says he throws back his catch but a lot of others here can't afford to pass up the meal.
The reservoir is one of thousands of sites along the U.S.-Mexico border where industry, pesticide use and population growth left hazards in past decades that still await solutions. Donna is among the worst _earning a place on the Environmental Protection Agency's priority list _ and illustrates how slowly the government cleanup process moves and how those struggling for subsistence in poor areas like this sometimes do not wait.
Four years after the site made the priority list, the EPA plans to begin soon extensive sampling of the water, sediment and fish that could become the foundation for a cleanup plan.
But with limited funds and an elaborate process, the effort could take years, leaving authorities to educate a population that is often more concerned with daily survival than warnings of potential problems. Donna reservoir is surrounded by fields of swaying sugarcane and green leafy rows of celery. Workers who toil in migrant agriculture live in sparse neighborhoods of trailer homes and campers that border the canal. Some stubbornly believe they can cook the chemicals out of the fish, state environmental officials say.
"They just don't tend to pay attention to that (sign)," said Juan Salazar, 41, who became so frustrated by the fishermen crossing his yard to reach the water that he erected a small fence.
"There are too many low-income families here that may make a living selling this stuff."
State and federal officials have repeatedly gone door-to-door to warn residents since PCB contamination was discovered in 1993. Twice federal authorities used electric charges to kill more than 35,000 fish in the reservoir and the 6 1/2-mile canal that brings water from the Rio Grande. But the fish _ at least 22 species, including tilapia and largemouth bass _ repopulate.
Every day, people are drawn to the tranquil scene, where birds feed along the shores and fish constantly break the surface. Officials believe many area residents fish there to supplement their diet. But in the fatty tissue of the fish are polychlorinated biphenyls or PCBs, an industrial residue apparently emanating from something dumped in the canal years ago. Officials say it could be a submerged piece of machinery but haven't been able to find it.
PCBs, typically found as oily liquids in electrical equipment, have been banned in the U.S. since 1979 after causing cancer in animal testing. Researchers believe the chemicals can lead to lower birth weights, suppress the immune system and increase the risk of cancer.
A carp caught in the Donna canal 19 years ago contained more than 1,500 times the limit of PCBs believed safe, the highest such reading ever. Members of the family who ate it had elevated PCB levels in their blood. Readings taken since then in the lake have been lower but still in the hazardous range.
However, the health impact on those eating Donna reservoir fish is unknown because no health survey has been conducted. A 2010 study by Texas Department of State Health Services estimated nearly 4,000 people living within a one-mile radius.
The EPA is planning a community meeting in late March to begin the process that could lead to a cleanup plan. One of the best-known PCB cleanup efforts _ on a much larger scale _ continues in New York's Hudson River more than 27 years after it made the priority list. Tons of sediment have been dredged from the riverbed.
Though nearly a dozen people were interviewed near the reservoir for this story, only one admitted to eating the fish he caught, but he then declined to speak further _ there is a $500 fine for taking the fish, but not if you throw them back.
Officials said some men in the area tend to shrug off the danger but women have been more receptive. Rafael Casanova, EPA project manager, said a pregnant woman he talked to during a local canvas told him she had bought lake fish from someone selling it in the neighborhood.
When he described the health danger, "She was very impressed by that," he said. "I felt good about that one."