by Ken White

GLOBE-Net, June 10, 2012 - Canada's renewable water supplies are being threatened by vast amounts of municipal and industrial waste being disposed of in rivers, lakes and other marine areas. Those industries largely responsible are not paying their share for the clean up according to Statistics Canada.

The Industrial wastewater business is huge involving water costs of $1.7 billion and water treatment costs of $656 million in 2009. However, there is a huge imbalance for the largest discharger of wastewater (thermal electric) compared to the largest water treatment expenditures (manufacturing).

The thermal electric sector, while it releases by far the highest amount of wastewater, is investing only marginally in the treatment of this wastewater. 

Industrial Wastewater refers to liquid waste discharged from industrial activities. Thirty-one billion cubic metres of wastewater were discharged for manufacturing, mineral extraction and thermal-electric power generation in 2009.

Thermal-electric power producers accounted for 82% of the wastewater discharge, followed by manufacturing industries (16%) and mining industries (2%).

Industrial Wastewater Treatment and Discharge Costs

Industries discharging industrial wastewater invested $655.7 million on wastewater treatment, which represented 38% of total industrial water costs in 2009.     

Manufacturing industries spent $575.7 million on wastewater treatment and discharge, 42% of their total water costs.

The paper industry accounted for the largest share of this total at $274.1 million.

The food manufacturing industry spent $100.0 million, the chemical manufacturing industry $77.7 million, and the primary metals manufacturing industry $61.8 million on wastewater treatment and discharge.  

Mineral extraction industries spent $70.6 million on wastewater treatment and discharge, roughly 43% of their total expenditures on water.  

Thermal-electric power producers use large quantities of water for cooling, condensing and for steam. The industry spent relatively little ($9.5 million or 6%) on water treatment and discharge as a proportion of their total water costs in 2009. 

Industrial Wastewater Discharge Destination and Treatment

Manufacturing industries discharged most of their wastewater (77%) to surface freshwater bodies, tidewater (11%) and to public and municipal sewers (8%). The balance was discharged to groundwater or other areas.  

Of the water discharged by manufacturers, 34% was not treated before release. 

Eighteen percent of the total discharge received primary treatment, 39% underwent secondary or biological treatment and 9% underwent tertiary or advanced treatment. 

Mining industries discharged most of their wastewater (73%) to surface freshwater, while discharging another 11% to tailing ponds and 9% to groundwater.  Metal mines accounted for the largest proportion of wastewater discharged to tailing ponds. Of the total water discharged by mining operations, 60% was not treated before discharge, 31% underwent primary or mechanical treatment and only 9% underwent tertiary or advanced treatments.  

Thermal-electric power generation industries discharged 95% of their wastewater to surface freshwater bodies. Almost 59% of this water was not treated before being discharged.  

Ammonia and nitrate made up 90% of the total tonnage of substances released into water by industrial facilities in Canada in 2009.

Industrial Water Recirculation

Water recirculation, the process of using the same water more than once in a system, reduces the need for industries to take in new water.  In 2009, 8,639.9 million cubic metres of water were recirculated by the manufacturing, mining and thermal electric power generation industries. The recirculation rate, defined as the amount of recirculated water as a percent of water intake, was 27%.  

Manufacturing industries recirculated 2,872.2 million cubic metres of water, 53% of their total water intake. The primary metal manufacturing industry had a recirculation rate of 95%. Mining industries reported the use of 1,547.7 million cubic metres of recirculated water in 2009, a recirculation rate of 311%. Almost all of the recirculated water (98%) was used for process activities by the mining industry. 

Thermal-electric power producers recirculated 4,220.0 million cubic metres of water, a recirculation rate of 16%.

Capital Expenditures

In 2008, $114.7 million in capital expenditures was invested in pollution abatement and control processes and technologies to reduce emissions to surface water, while capital expenditures on pollution prevention processes and technologies totaled $178.8 million. 

The paper manufacturing industry spent the greatest portion (34%) of their total capital expenditures on pollution abatement and control to reduce emissions to surface water, followed by the food manufacturing (19%) and chemical manufacturing (17%) industries. The mining and quarrying industry spent the greatest portion (62%) of their total capital expenditures on pollution prevention to reduce emissions to surface water.

Conclusion

The thermal electric generating industry is discharging 82 percent of Canada's wastewater followed by manufacturing (16 percent) and mineral extraction (2 percent). However, manufacturing accounts for 88 percent of water treatment discharge costs followed by mineral extraction (11 percent) and thermal electric (1 percent).

This article discusses industrial wastewater releases by the thermal electric industry, mining and manufacturing and compares wastewater releases and treatment costs for each of these sectors.  The article was prepared based upon a recent release by Statistics Canada on Human Activity and the Environment, June 5, 2012. Much of the text has been extracted directly from the published article by Statistics Canada on Industrial Wastewater.