A uranium frenzy in the 1950s and '60s resulted in tens of thousands of tons of radioactive mill tailings left behind after the boom went bust, not to mention the thousands of abandoned and potentially deadly open mines throughout southern Utah.

Above-ground nuclear testing in the late 1950s and early 1960s sent radioactive pink clouds billowing over unsuspecting residents in Nevada, Utah and Arizona. Thousands died of cancers believed linked to the tests.

Along the populous Wasatch Front, steel mills and smelters built to bolster the war effort contaminated surrounding lands and underground water with lead and arsenic while spewing deadly chemicals into the air.

Mining companies like Kennecott also contributed to a dangerous concoction of toxic byproducts handed down to future generations. The company is now spending hundreds of millions of dollars cleaning up the messes it made in the past.

Today, Utah is home to 20 actual or proposed Superfund sites, most of them located in Salt Lake, Davis, Weber and Tooele counties. With Superfund running out of money, another 14 contaminated sites have been targeted for cleanup under a different program that entails voluntary cleanup by property owners.

Additionally, four uranium mill sites have already been cleaned up at a cost of almost $1 billion, and cleanup at a fifth site, the Atlas mill outside Moab, is expected to cost as much as $300 million. Almost all of it is taxpayers' money.

But while billions are being spent to clean up the wastes dumped on Utah in the past, environmentalists and citizen activists question the wisdom of some of Utah's political leaders in the late 1970s and early '80s whose attitude of "waste is welcome here" opened Utah to non-Utah waste.

• Millions of tons of hazardous and radioactive waste generated in other states are now being dumped in Utah — specifically Tooele County, which is home to the nation's only commercial low-level radioactive waste dump, as well as one hazardous waste dump and two hazardous waste incinerators. (One is now shut down.)

• A commercial waste dump in Carbon County accepts wastes deemed hazardous in other states but not in Utah.

• A uranium mill in San Juan County accepts radioactive wastes from around the nation that are "recycled" to recover small traces of uranium.

• A military incinerator in Tooele County is being used to destroy massive stockpiles of chemical and biological weapons.

And it may not end there.

Sometime during the next two years, Utah could find itself a home to 40,000 tons of spent nuclear fuel rods — the most toxic of all nuclear wastes — as well as less-radioactive wastes resulting from the decommissioning of nuclear power plants around the nation.