Waste
Most mine waste is generated at our uranium mining operations in northern Saskatchewan, where it is safely stored in tailings management facilities.
We reuse waste rock where possible, but the amount of waste rock we can reuse depends on the type of rock that is generated and the number of projects in progress.
We use uneconomical mineralized waste rock as blend material for ore processing and for structural support in backfilling our underground mines. Clean waste rock is used in concrete mixtures, to build new facilities and to develop or maintain roads. This reduces the size of our waste rock piles and the amount of other natural aggregate resources we consume.
Tailing management facilities
Cameco pioneered in-pit tailings management facilities. These engineered facilities in mined-out open pits, designed to protect the environment for thousands of years, are now recognized as a best practice in tailings management around the world.
We treat our mill tailings to stabilize contaminants before placing them in the tailings facilities, and divert both surface and groundwater around them to reduce any impact. Runoff and seepage water from the tailings facilities and rock piles is collected and treated before it is released to the environment.
Cameco is also a leader in low-cost in situ recovery (ISR) mining technology for uranium. This involves circulating solutions through ore-bearing formations to dissolve uranium and pump it to the surface for recovery – an approach that results in minimal surface disturbance and produces no waste rock or mill tailings. We use in situ recovery methods at our operations in the US and Kazakhstan to extract uranium contained in sandstone aquifers.
Landfill waste
The amount of landfill waste we generate varies each year based on our activities. When more people are on site, more waste is usually generated, even when each person is generating slightly less waste than at other sites with fewer people.
The type of waste we generate also varies depending on our activities, which affects our waste diversion rates from year to year (for example, if a large proportion of the waste generated in one year was metal and could be recycled, the diversion rate might be higher that year compared to a year when there was less recyclable metal).
Similar to our direct and indirect energy use and greenhouse gas trends, we expect our waste volumes to increase as we expand our operations, increase production, deal with historic waste and progressively decommission our sites.
Our operations are looking for ways to reduce and divert waste, including industrial-scale composting, increased recycling and decontamination and incineration/gasification technologies.
GRI Indicators
EN22 – Waste
^This indicator provides information about the total amount of solid, semi-solid and liquid waste we generate and divert, except wastewater (EN21) and mine waste (MM3). It includes non-hazardous industrial waste, as well as hazardous waste and radioactive or radiologically contaminated waste, as defined by national legislation where the waste is generated.
| Units | 2009 | 2010 | 2011 | |
|---|---|---|---|---|
| Non-Hazardous Waste | ||||
| Generated | tonnes | 3,044 | 4,518 | 7,576 |
| Diverted | tonnes | 751 | 1,914 | 1,370 |
| Landfilled or Stored | tonnes | 2,293 | 2,604 | 6,206 |
| Rate of Diversion | % | 24.7% | 42.4% | 18.1% |
| Units | 2009 | 2010 | 2011 | |
|---|---|---|---|---|
| Radioactive Waste | ||||
| Generated | tonnes | 6,669 | 6,744 | 7,696 |
| Diverted | tonnes | 603 | 1,756 | 1,177 |
| Landfilled or Stored | tonnes | 6,067 | 4,988 | 6,519 |
| Rate of Diversion | % | 9.0% | 26.0% | 15.3% |
| Units | 2009 | 2010 | 2011 | |
|---|---|---|---|---|
| Hazardous Waste | ||||
| Generated | tonnes | 381 | 451 | 226 |
| Diverted | tonnes | 385 | 447 | 225 |
| Stabilized & Disposed | tonnes | 0 | 4 | 1 |
| Rate of Diversion | % | 101% | 99% | 100% |
Includes all divisions except corporate offices and exploration.
What it means
The amount of waste we generate depends on the activities we're involved in. In recent years, we have generated more waste as a result of expanding operations and efforts to clean up legacy waste from across our sites. There is a direct correlation between the amount of waste generated and the amount of people on site. When more people are on site, more non-hazardous waste is usually generated, even when the per-person generation rates diminish slightly.
The type of waste we generate varies depending on our activities, which affects our waste diversion rates from year to year. For example, if a large proportion of the waste generated in one year was metal and could be recycled, the diversion rate might be higher that year compared to a year when there was less recyclable metal.
Looking ahead
Similar to our direct and indirect energy use (EN3 and EN4) and GHG trends, we expect our waste volumes to increase as we expand our operations, increase production, deal with historic waste and progressively decommission our sites. We are pursuing waste diversion initiatives to minimize the amount of waste we landfill.
MM3 – Mine waste (overburden, rock, tailings, sludges)
^This indicator provides information about the amount of mine waste we generate and re-use.
Mine waste includes stockpiled overburden, mineralized and non-mineralized waste rock, and tailings. It also includes loadings from process waste water as referred to under EN21, sludges, slimes and other process residuals.
| 2009 | 2010 | 2011 | |
|---|---|---|---|
| Total Mine Waste Generated | 423,454 | 539,319 | 622,198 |
| Total Change in Wasterock Inventories | -113,110 | -63,155 | 47,431 |
| Total Tailings & Process Wastes | 536,564 | 602,474 | 574,767 |
What it means
Despite efforts to use our waste rock material rather than stockpiling it whenever we can, the net amount of mine waste we've generated has increased over the past three years. This is due to expanding underground operations at our northern Saskatchewan operations. The negative values shown in the chart indicate where we were successful in re-purposing stockpiled rock in excess of the fresh waste rock being generated.
The amount of waste rock we can reuse depends on the type of waste rock that is generated and the number of projects in progress (which affects the amount of aggregate we need).
We use uneconomical mineralized waste rock as blend material for ore processing and for structural support in backfilling our underground mines. Clean waste rock is used in concrete mixtures, to build new facilities and to develop or maintain roads. This reduces the size of our waste rock piles and the amount of other natural aggregate resources we consume.
Looking ahead
Similar to our direct and indirect energy use (EN3 and EN4) and GHG trends, we expect our mine waste volumes to increase as we expand our existing operations or open new facilities. We will continue to re-purpose as much of this material as possible.
About deep well injection
For safe disposal of process waste streams at some of our in situ recovery (ISR) operations, Cameco utilizes a liquid waste disposal technology called deep well injection. This method uses injection wells to place treated and untreated liquid waste into confined geologic formations where they will not migrate into potable aquifers. Cameco's wells are classified as Class 1 Non-Hazardous Industrial Waste disposal wells. The depth of these wells varies depending on the geologic characteristics of the site ranging from average depths of 1000 to 2700 metres, with the majority completed at the latter depth. For more information about deep well injection, please visit the US EPA site: http://water.epa.gov/type/groundwater/uic/wells_class1.cfm.