The Smelter uranium depository on the southern flanks of Smelter Mountain. The Department of Energy monitors the groundwater at the site in order to detect any possible leaks from the containment cell./Photo by Steve Eginoire

On the rise again

Dept. of Energy reports increase in uranium levels at Smelter containment site
by Tracy Chamberlin

Uranium levels are on the rise again at a disposal site just north of Lake Nighthorse.

Readings from one of the wells at the uranium mill tailings disposal site have almost doubled in the past year, according to a report from the Department of Energy, and agency officials don’t know why.

“It is high, and we don’t have a good explanation for it at the moment,” said David Shafer, an Environmental Team Leader with the DOE’s Office of Legacy Management, in Grand Junction.

The last time levels jumped up in 2009, the sight was redeveloped. Subsequently, uranium concentrations dropped. But the numbers began rising again and recently peaked at the highest concentration to date.
Former Smelter Mountain site workers eligible for federal aid

Former workers at the Durango Disposal and Processing sites could be eligible for compensation and medical benefits, according to the U.S. Department of Labor.
After a facility in Shiprock was determined to be eligible for coverage under the Energy Employees Occupational Illness Compensation Program Act, a federal review was performed to determine the possible inclusion of other facilities and time periods.

Seventeen facilities associated with the Uranium Mill Tailings Radiation Control Act were added to the list or their time periods were extended, including the uranium mill in Durango.

Former and current employees who suffered from such illnesses as cancer, beryllium disease or silicosis caused by exposure to radiation, beryllium or silica during their employment with the DOE or its contractors and subcontractors could be eligible for the benefits. This includes the survivors of qualified workers.

Those who worked at the Durango mill from 1948 - 53 were already covered, but the time period of October 1986 - May 1991 was added. This is the time period the disposal and processing sites near Smelter Mountain were built.

Other Colorado sites that have been added to the coverage list include: the Climax Uranium Mill in Grand Junction from December 1988 - August 1994; Gunnison mill from September 1991 - December 1995; Maybell Mill from 1995 - September 1998; Naturita Mill from May - November in 1994 and June 1996 - September 1998; the old and new mills in Rifle from September 1988 - September 1989 and April 1992 - October 1996; and, the No. 1 (East) and No. 2 (West) uranium mills in Slick Rock from 1995 - 1996.

For more information on compensation and benefits, contact the Denver Resource Center at 720-540-4977.

- Tracy Chamberlin

The DOE monitors the groundwater at the disposal site in order to detect any possible leaks from the containment cell and is required to publish an annual report on its maintenance, repair and testing results.

In the 2011 Site Inspection and Monitoring Report, uranium levels in a monitoring well located near the northeast corner of the cell were far above standards and have been on the rise for the past year.

Levels hovered below the site-specific standard of 0.077 milligrams per liter for most of 2010, but shot past that minimum mark in 2011. They recently hit an all-time high of 0.14 milligrams per liter.

Shafer said the most recent reading, taken in the beginning of February, showed the levels back down to the 2009 highs of 0.12 milligrams per liter, but still well above the site standard and the EPA standard, which is 0.004.

And the cause for the increased readings is unknown.

DOE officials said it could be a naturally occurring phenomenon, noting the high levels of uranium commonly found in the area and the uniform readings of other sampled elements. Selenium and molybdenum levels are also monitored.

“In this well we don’t see some of the other types of groundwater contaminants,” Shafer said. He added that uranium concentrations are also consistent among the other six wells that make up the monitoring network.

According to Jalena Dayvault, the Durango Disposal and Processing Site Manager, an investigation is under way to determine the cause for the rising concentrations.

The first step in the process was to increase the sampling schedule to monthly readings. Next they removed a permeable reactive box, part of the water treatment process, closing off a drain that runs along the edge of the containment cell and a potential source of well contamination. They determined the box was not damaged and the drain was not affecting the well readings.

“We’re trying to determine the source,” Dayvault said. “… and that’s still being investigated.” She added that although the cause for the increase in uranium levels is unknown, she does not believe residents in the area are at any risk of exposure.

Currently, the DOE is increasing the number of elements tested for in the samplings and monitoring the water levels in the aquifer. Weather permitting, another sample will be taken at the end of February.

By increasing data collection and examining the information, they hope to get a clearer picture and possible answers for the increase in uranium levels.

“One of the problems is that the DOE is notorious for airing on the side of not finding problems,” said Travis Stills, an attorney with Energy and Conservation Law in Durango.

The final section of the report does state that “no corrective action was required in 2011.”

Dayvault said that is not because nothing is being done, it is regulatory language concerning out-of-compliance issues and that the DOE plans on continuing its investigation.

When uranium levels skyrocketed in 2009, the DOE took a similar approach by checking the infrastructure first. The response was to overhaul the well and reevaluate the purging method and pumping materials.

“We wanted to make sure the way the well was constructed wasn’t contributing to the readings,” Shafer said.
 
After reconstruction was complete, readings again dropped below the site-specific standards but began to rise again early in 2010.

The well in question, number 0618, is one of three drilled into the sedimentary aquifer on the northeast corner of the disposal site, home to 2.5 million cubic yards of radioactive materials.

It was added to the monitoring system in 2002 as a companion to an adjacent well, which was drilled to 10 feet above the bottom of the aquifer. Well number 0618 was drilled to the bottom of the aquifer.

Although the groundwater beneath the 42-acre disposal cell is not considered suitable for domestic use, it is an indicator of the containment cell’s performance.

Built in the late 1980s, the cell houses the tailings and other contaminated leftovers from the old Smelter uranium-processing facility that was in operation from 1949 - 63.

The area was also home to a former lead smelter operation and vanadium mill. Almost 1.2 million cubic yards of radioactive mill tailings were produced and an additional 53 acres were contaminated by the tailings and raffinate liquids.

“Durango has a long-term problem with uranium and radioactive materials,” Stills said. “And the DOE tends to sweep the problem under the rug.”
He added that it’s going to take diligence from the residents of Durango and Southwest Colorado to keep on top of the situation.