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DENVER — The Colorado Department of Public Health and Environment is closely working on emergency repairs to cracks on a protective clay layer covering a landfill on the Rocky Flats nuclear waste site.

The cracks were discovered after the heavy rainfall that fell on the area two weeks ago.

Rocky Flats, located between Golden and Boulder, manufactured plutonium triggers for nuclear bombs from 1952 to 1992.  In 1989 weapons production ended when FBI agents raided the plant after it was discovered that operators were violating anti-pollution laws.  The plant was shutdown in 2002 and declared a wildlife refuge.

By 2005 the site was declared clean, however some plutonium residue was left behind.

Underneath a landfill at the site are old building materials. Tests showed no plutonium contamination, but there is always that possibility, said Carl Spreng, the Rocky Flats Coordinator for the Colorado Department of Public Health and Environment.

The cracks in a clay layer above the building materials will need to be repaired Spreng said.

Kristen Iverson used to work at the plant and grew up by the nuclear weapons facility.

“There was so much contamination, the Department of Energy, declared it the most contaminated site in America,” Iverson said.

She said the recent floods probably took plutonium residue off the site and into two creeks that run off the site.

“I think people should be concerned,” she said from Memphis, where she is now a college professor. “There was a great deal of water coming off the site. Keep in mind it is an area of high erosion.”

FOX31 Denver checked out the area, focusing on Woman and Walnut Creek. Visually, you can see where water levels were higher than normal — weeds by the shoreline bent back by the heavy waters from the storms more than two weeks ago.

“There is always concern,” said Spreng. “That’s why we continue to monitor the water that comes off the site.”

The state, along with the Department of Energy, monitors ten water sampling stations around Rocky Flats, looking for any residue of plutonium that may come off the site. Spreng said the majority of those sampling sites are by the two creeks and are carefully monitored.

“The residue amounts we worry (about) might get into surface water, that’s why we carefully and constantly monitor the surface water,”he said.

Despite two of those monitoring stations failing for a period during the storm, he said results shouldn’t be skewed and should be back from two different labs in a couple of weeks.

FOX31 Denver teamed up with the Colorado School of Mines to test the area near the creek beds.

Dr. Jeffrey King, a nuclear engineer, who tests for radiation levels in a working environment helped with our tests. Using a monitor that detects alpha, beta and gamma radiation, he was unable to find anything alarming.

He also used swabs on four sample locations, two by the creeks where residue could be coming off the Rocky Flats site.

King told FOX31 Denver the tests showed no alpha radiation counts.

“In all cases, this is considered less than minimal detectable activity,” King said.

He said the state’s test could yield more sensitive tests, but from a general safety standpoint, he did not find any radioactive material.

The CDPHE said it would share its water results with FOX31 Denver when it comes back in the next few weeks.

CDPHE also said water from the site is diverted to the South Platte and does not enter the drinking water system.