HILL AIR FORCE BASE — For decades, certain chemicals used at Hill Air Force Base were thrown out the back door or dumped in disposal trenches.

That was back when cars were built without seat belts and ran on leaded gasoline, and people smoked menthol cigarettes to freshen their breath and add a sparkle to their smiles. The nation hadn't yet developed an environmentally concerned part of the brain.

Those chemicals at Hill, mostly degreasers like trichloroethylene, sat on the ground and leaked into a shallow groundwater system. The contaminated groundwater spread and can now be found in 16 locations on and off the base. Some of the contaminated plumes have flowed to parts of Layton, Clearfield, Sunset, Clinton, Roy, Riverdale and South Weber.

Other contaminants, including chromium, asbestos, petroleum and arsenic, are found in the soil around the groundwater plumes.

Back in the 1970s, the nation became more environmentally aware, Congress passed regulations and laws regarding the disposal of chemicals, and practices at the base began to change.

But the legacy of contamination remains. Hill and its surrounding area were declared a Superfund site in 1987 and added to the U.S. Environmental Protection Agency's National Priorities List. That designation means that human exposure to contaminants is not under control.

Contamination from the base was about 30 years in the making. It's taken another 30 years and $210 million to get most cleanup plans in place and work started. And it'll be another 30 to 65 years and at least $320 million more before the water is clean again.

"We're a lot smarter now," said Steve Hicken, an environmental engineer and project manager over the cleanup effort around Hill.

The Superfund designation came after Brent Poll's family first brought the pollution to the government's attention 35 years ago. The Poll family farm in South Weber borders the base. Poll's brother, Glen, found brackish water coming from family-owned springs in the 1960s.

The springs used to have the cleanest, best-tasting water, Brent Poll said, and the family used to run cattle on the land. The Polls can't do that now, because the water is contaminated.

The Polls told Hill officials about the problem, but the officials denied for years that pollution was coming from the base, he said. Then, in the 1970s, orange water, laden with metals, began to flow from the hillside and eventually covered acres of his land. That's when officials began to listen, Poll said.

Two contaminated areas are currently located on his property. "Basically, what we are is guinea pigs out here," he said.