Petition Status


Current Goal
: 14500 People by June 1, 2012

Support To-Date: 14247 People (January 15th)

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Numerous articles, editorials, and letters to the editor are being published in local newspapers concerning uranium mining in northern Colorado. To view them, see the Reference page.
Irrigation with Wastewater - Land application Print

On January 21, 2009 Powertech reported they had collected soil samples in support of a land application process at their proposed Centennial Project. The results were incorporated into permit applications. A permit for land application would allow the irrigation of uranium-mining wastewaters onto the surrounding soil.

The Argonne National Laboratory had the following to say about land application of uranium mining wastewaters:

Radionuclide - containing water, either from purge water from production well fields or from restoration wastewater from restoration well fields, is treated to unrestricted release levels and disposed of by irrigation. Release onto the soil surface will contaminate the soil at the land application areas. The radionuclides adsorbed by the soil will become a source term for radioactive release through wind (

It has been reported “all of the areas planned to be mined by Powertech are well within the present property boundaries and do not conflict with adjacent ownership” ( Powertech’s planned land application for wastewater disposal might be within their property boundaries, but the contamination might not stay there. Wind erosion from Weld County’s hurricane force winds could loft dry contaminated soil far and wide (Click here to see a map of wind directions and communities downwind from the Centennial Project).

Runoff from a 2006 thunderstorm originated from the flattop mesa in Weld County where Powertech proposes to operate uranium in situ leaching. This type of runoff might flow through acreages where land application is proposed to be used for disposal of the mine’s hazardous wastes, dispersing heavy metals and radioactive material to properties and waterways down gradient from the site.

Seasonal storm runoff might wash over the soil irrigated by uranium mining wastewater and move contaminates off site, onto properties adjacent to the mining operation, or further down gradient in the South Platte River Basin. The proposed Centennial uranium mine is within a network of connected dry washes, arroyos, and gullies which signify a history of runoffs and floods. According to meteorologist Mike Nelson, “it is not uncommon during the middle and late summer for a thunderstorm to produce 3 to 6 inches of rain in just a few hours’ time. This kind of downpour cannot completely soak into the soil, so it runs off into ditches, dry washes, and low-lying areas.” (Colorado Weather Almanac)

June 22nd, 2009 thunderstorm dumped 4” of rain in Laporte, 3” in Fort Collins, 2 ˝” in Wellington and produced tornadoes near Nunn. 17 hours after the storm, Coalbank Creek was still flooded with storm runoff coming from the area where Powertech hopes to conduct uranium mining.
A rainstorm over land application areas might move hazardous and radioactive soils downstream into wells, boreholes, ponds, grazing areas, and waterways. Any well or borehole into an aquifer may become a point source for contamination if infiltrated by flood/runoff water.

An intermittent stream across Weld CR21 in July of 2008 moving towards Nunn, Colorado. The waters originated on the flattop mesa where Powertech has proposed to operate an in situ leach mine for uranium.

The proposed Centennial Project is within the boundaries of three groundwater resources: the South Platte River Basin’s alluvial aquifer, Denver Basin’s Laramie-Fox Hills Aquifer, and the Dakota-Cheyenne Aquifer.

The Ground Water Atlas of Colorado describes the Dakota-Cheyenne aquifer as the most extensive water-yielding unit in eastern Colorado with over 27,500 wells on record as of 2003. The aquifer’s average hydraulic conductivity in the area of the proposed Centennial uranium mine is 0.03 feet per day.

The Laramie-Fox Hills aquifer is a significant water source for commercial and municipal wells. The Larimer-Fox Hills is the lowest layer of the Denver Basin where, as of February 2001, 33,700 wells had been recorded. The groundwater movement of the Laramie-Fox Hills aquifer in Weld County is toward the South Platte River.

Map courtesy of Colorado’s Department of Natural Resource’s Ground Water Atlas of Colorado

“In the lower South Platte River basin there are approximately 10,880 permitted wells of record listed” (Ground Water Atlas of Colorado: pg 42). Recharge for the lower South Platte River Basin aquifer is done through infiltration from rain and snow, infiltration from ponds, and inflow from its tributaries. If those recharge waters originate at a land application/irrigation site for a uranium mine, contaminates may flow into the aquifers with runoff water. “Irrigation water, from agricultural as well as landscape applications, can recharge ground water, sometimes with detrimental effects. Fertilizers, pesticides, and fungicides move with the irrigation application water to the aquifer and then via ground-water flow to nearby streams.” (Ground Water Atlas of Colorado)

Map courtesy of Colorado’s Department of Natural Resource’s Ground Water Atlas of Colorado

Uranium mining contaminates may spread in other ways besides wind and rain erosion. Studies have shown plants growing on uranium mining wastes have a high uptake of radionuclides. A 1988 article in The Journal of Radioanalyical and Nuclear Chemistry titled A Study of Radionuclides in Vegetation on Abondoned Uranium Tailings found grass-like plants growing on abandoned uranium tailings had high levels of radionuclides in the above ground parts. Woody plants on those tailings had high uranium accumulation in their roots. This plant uptake would result in the spread of radioactive material from the site. Near holding ponds at a uranium mine site on the Spokane Indian Reservation it was reported "enough contaminants, including uranium, have leached into plants and nearby creeks that one federal study estimated a person eating plants and animals from the area and using the water for sweat lodges could have a 1 in 5 chance of getting cancer." (

Soil irrigated with uranium mine wastewater might spread contaminates from plants that absorb the toxic elements, to the insects that eat the plants, to the birds that eat the insects, to the animals that eat the birds. Kesterson National Wildlife Refuge provides an example of problems that occurred when irrigation water created unnatural concentrations of the element selenium. (See Selenium Case Study: Kesterson National Wildlife Refuge.)

Selenium, common in the soils along the Front Range and throughout eastern Colorado, may become problematic for uranium mining in Weld County. Unnatural concentrations of selenium in Kesterson’s water resulted in an entire food chain carrying high levels of the element. Selenium caused death and deformities in all animal populations. In surface areas where selenium becomes concentrated, locoweed and other selenium loving plants can replace natural vegetation. These plants are toxic and deadly to the animals that eat them (see Selenium Contamination).

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