In Yigo, the northernmost village in Guam, there is a well that cannot be shut down.

Known as Y-15, the well sits atop the island’s northern aquifer, which supplies around 80% of the island’s drinking water. Even if contaminants are detected, Y-15 has to keep pumping. There is simply no alternative.

The well also sits just below a hill near Upi Elementary School—attended by around 400 children—and just outside the back gates of Andersen Air Force Base, which hangs over the community like a permanent shadow. Generations of Indigenous CHamoru families have called Yigo home, relying on these waters for drinking, cooking, and other daily activities.

But in September 2025, one such family learned that the well supplying their home of 17 years was contaminated with high levels of dieldrin, a pesticide once widely used on crops and for termite control beginning in the 1950s. The Environmental Protection Agency (EPA), which classifies dieldrin as a probable human carcinogen, banned all uses of the pesticide in 1987 over concerns about its damage to the environment and links to serious health effects, including cancer, Parkinson’s disease, and reproductive issues such as decreased fertility and increased numbers of stillbirths. Because dieldrin accumulates in the body, long-term exposure—even in small amounts—can cause serious harm, according to the EPA.

More than 1,200 residents of Yigo were told not to drink water from Y-15 because of dieldrin contamination.

The news hit Leevin Camacho, the homeowner who learned of the contamination, with a mix of anger and fear. He thought immediately of his two young sons. Although members of his family don’t drink straight from the tap, the water touches nearly everything they do: cooking meals, brushing their teeth, showering at the end of long, humid days.

“While we were there feeding our kids, doing a lot of stuff, there was pesticide in the water,” he told Prism in November.

Camacho knew his family could adjust to the “do not drink” order issued by Yigo officials. As a lawyer and former attorney general of Guam who grew up in a military household, he had the resources to install a costly home filtration system or buy bottled water each week. But he worried about everyone else in Yigo—especially fellow CHamorus who, unlike him, didn’t have as many options.

Read the full article about the U.S. Defense Department's environmental harm in Guam by Gaea Cabico at Prism Reports.