Dorado, Puerto Rico (CNN) Jose Luis Rodriguez waited in line Friday to fill plastic jugs in the back of his pickup truck with water for drinking, doing the dishes and bathing.

But there is something about this water Rodriguez didn't know: It was being pumped to him by water authorities from a federally designated hazardous-waste site, CNN learned after reviewing Superfund documents and interviewing federal and local officials.

Rodriguez, 66, is so desperate for water that this news didn't startle him.

"I don't have a choice," he said. "This is the only option I have."

More than three weeks after Hurricane Maria ravaged this island, more than 35% of the island's residents -- American citizens -- remain without safe drinking water.

It's clear some residents are turning to potentially risky sources to get by.

Jose Luis Rodriguez

Friday afternoon, CNN watched workers from the Puerto Rican water utility, Autoridad de Acueductos y Alcantarillados, or AAA, distribute water from a well at the Dorado Groundwater Contamination Site, which was listed in 2016 as part of the federal Superfund program for hazardous waste cleanup.

Residents like Rodriguez filled small bottles from a hose and piled them in their vehicles. Large trucks with cylindrical tanks on their backs carried the water to people elsewhere. Some of the trucks carried the name of the municipality of Dorado. Others simply were labeled with the words "Agua Potable," Spanish for potable water.

In announcing the addition of the Dorado site to the Superfund program, the US Environmental Protection Agency says the area was polluted with industrial chemicals, including tetrachloroethylene and trichloroethylene, which "can have serious health impacts including damage to the liver and increasing the risk of cancer," according to the EPA.

EPA 'gathering more information'

It's unclear whether there are public health risks from this particular well, however.

The EPA said it plans to do testing in the area over the weekend.

"The EPA is gathering more information about the quality of water from the wells associated with our Dorado groundwater contamination site, as well as other Superfund sites in Puerto Rico," the agency said in a statement issued to CNN on Friday. "While some of these wells are sometimes used to provide drinking water, the EPA is concerned that people could be drinking water that may be contaminated, depending on the well. We are mindful of the paramount job of protecting people's health, balanced with people's basic need for water."

Regional EPA spokesman Elias Rodriguez confirmed the location is part of a Superfund site.

Autoridad de Acueductos y Alcantarillados, the water authority, was unaware that this well site was part of the Superfund program until CNN provided maps showing that this was the case, according to Luis Melendez, sub-director for environmental compliance at the utility.

Melendez maintained the water is fit for public consumption. The well was opened on an emergency basis and is not part of the regular drinking water supply, he said.

In 2015, this well in Dorado, which is located near a shopping center, was found by the EPA to be safely within federal standards for PCE and chloroform, two industrial chemicals.

'I've never seen this before'

Martyn Smith, a professor of toxicology at the University of California, Berkeley, told CNN the levels of PCE and chloroform would be essentially safe for human consumption. "I wouldn't have any problem in drinking this water if these were the only chemicals in it," he said. The problem with Superfund sites, he said, is that you don't know what else is present.

"I've never seen this before," he said, referring to the idea a Superfund site would be used as a source of public drinking water. Boiling the water, he said, would reduce possible contamination. And it's somewhat understandable, Smith added, that people in Puerto Rico would turn to possibly questionable drinking water sources given the scope of the crisis.

Still, a Superfund site -- a location with known health risks -- is just about the last place a person would want to turn to find drinking water, even in a crisis, said Erik Olson, head of the health program at the Natural Resources Defense Council, an environmental advocacy group.

"There are thousands of chemicals out there that could be in a Superfund site and only a relative handful are covered by standards," he said. "What I would be worried about is stuff that isn't showing up on EPA's drinking water standards. It just sounds really risky to me to be serving water out of a Superfund well."

People waiting in line for water on Friday were largely unaware of these concerns. Some of them had heard the EPA announced this week that it had received reports that Puerto Ricans were getting water from Superfund sites. But those interviewed assumed that wasn't this well.

Mayra Perez, a 59-year-old retiree, expressed pride in the quality of the water.

"I'm sure there are no chemicals in this water," she said.

Aixa Chevere, a mother of two, said she would find a new source of water if this site was shown to be contaminated. Already, the family spends three to four hours per day waiting in lines for basic services and goods, including water. "We would boil the water or search for bottled water" if it were dangerous, she said. "We would find some other alternative."

That day, however, she loaded the water into her trunk of her car.