The Colorado Department of Public Health and Environment has disclosed the amount of plutonium in a soil sample collected near the Jefferson Parkway.

JEFFERSON COUNTY, Colorado — A soil sample taken near Rocky Flats has tested for an elevated level of plutonium five times higher than cleanup standard set to protect public health.

The Colorado Department of Public Health and Environment (CDPHE) disclosed the soil sample findings in a letter to community members who live near the future Jefferson Parkway near the old Rocky Flats nuclear weapons facility.

As part of the future toll road, the Jefferson Parkway Public Highway Authority is voluntarily taking soil samples in the area around Indiana Street between 96th and 120th Avenues.

One of the 250 soil samples taken in May and June tested for 264 picocuries per gram of plutonium. The cleanup standard for Rocky Flats is 50 picocuries per gram. The state health department said that standard was set to protect public health with a margin of safety.

A second test of the same soil sample resulted in 1.5 picocuries per gram of plutonium.

"Based on the information we have so far, our state experts and toxicologists do not believe there is an immediate public health threat," the state health department wrote in a letter to the community. "We do believe that further sampling and analysis is needed to assess what this elevated sample may mean for long-term risks, and whether it is an isolated instance, or a sign of a wider area of relatively high contamination. We are taking the sample result seriously because it is much higher than previous samples in the vicinity and higher than the cleanup standard.

“Again, we are seeking additional data, and will review it as it becomes available to determine how to proceed in a way that protects public health and the environment."

A picocurie is a unit that measures radio active decay, according to Dr. Mark Jensen, a chemistry professor at the Colorado School of Mines and university chair of nuclear science and engineering.

"A picocurie is exactly 2.22 atoms disintegrating in a minute,” Jensen said. “Fifty picocuries represent 100 plutonium atoms that have disintegrated over the course of a minute."

The Jefferson Parkway would connect the Northwest Parkway to Highway 93, and perhaps complete a circle of free and tolled roads around the metro area.

The executive director of the Parkway Authority said it was taking soil samples voluntarily because none had been tested since 2006.

"I think knowing the truth is always the better thing," said Bill Ray, the executive director of the Jefferson Parkway Public Highway Authority. "The public needs to be aware and informed and I think the Colorado Department of Public Health and Environment is the one who can advise us all, is that if there any risk and, if so, to what proportion."

The state health department said that the Parkway Authority will now do additional testing in the area where the soil sample with the elevated level was taken.

"The department believes this is an appropriate and needed next step,” the state health department wrote in the letter to the community. “As soon as all the tests are processed and verified by the laboratory, the department will review the final soil sampling results, identify additional needed sampling, and share this information with the public. The department has also been in contact with the U.S. Department of Energy and Environmental Protection Agency regarding the sample,"

Jensen said he wasn’t surprised that a hot particle was found in the area. On Monday, Jensen talked with Next about fine particles of plutonium being dispersed throughout the metro area because of previous fires at Rocky Flats.

"I don't think we should be surprised to find a single sample that exceeds 50 picocuries per gram potentially anywhere in the metro area," Jensen said.