Water Quality

We continually work to improve water quality, in particular by reducing biodegradable organic materials in wastewater. When left untreated, biodegradable organic materials can contribute to low dissolved oxygen levels in receiving waters, which may harm some aquatic organisms. High levels of untreated solids, measured as total suspended solids, can reduce river clarity, inhibit photosynthesis, and damage fish and aquatic insect sediment habitat.

We also work to protect water quality in areas where we grow and manage timber. We grade and maintain roads so runoff is channeled to the forest floor, keeping silt away from streams. We build culverts and bridges to allow fish passage, and we seed exposed road banks with grasses to prevent erosion.

Wood Products — Water-Quality Measures
Estimated discharge of selected pollutants in pounds per ton of production
	2005	2006	2007	2008	2009
Biochemical oxygen demand	0.02	0.03	0.03	0.03	0.03
Total suspended solids	0.01	0.02	0.01	0.01	0.01

Discharge of Adsorbable Organic Halides

Because we no longer use elemental chlorine for pulp and paper bleaching, our discharges of adsorbable organic halides have decreased by more than 93 percent between 1990 and 2009.

Discharges of Adsorbable Organic Halides
Pounds of AOX discharged per ton of bleached production from Weyerhaeuser's cellulose fibers mills²
	1990¹	2005	2006	2007	2008	2009
AOX	5.1	0.3	0.3	0.3	0.3	0.3

Base year is 1990.
Data reflects performance of Weyerhaeuser’s 2009 portfolio of cellulose fibers mills. In March 2007, Weyerhaeuser’s fine paper business and related assets were combined with Domtar Inc. to create a new fine paper company, Domtar Corporation. In August 2008, Weyerhaeuser’s containerboard, packaging and recycling business was sold to International Paper. Operations involved in those transactions have been removed from historical data.

Wastewater Dioxins

Weyerhaeuser eliminated the use of elemental chlorine to bleach and whiten pulp at all of our mills in the late 1990s. As a result, the concentration of dioxins—-a byproduct of elemental chlorine—has dropped to nondetectable levels in treated mill wastewater across company operations.

Our pulp is produced using advanced technologies such as extended delignification (removing lignin, a chemical that binds wood fibers together), that further reduce the amount of bleaching chemical used in the production process. These improvements have virtually eliminated dioxins from our wastewater while continuing to meet customer expectations for brightness in our paper products.

Pollution-control systems

Minute amounts of dioxin are released through permitted air emissions, such as from biomass-fired boilers, which burn wood residuals such as bark. Just as campfires release dioxin, so do our mills when we burn biomass fuel. We're addressing the environmental impact through techniques that improve combustion efficiency and temperature controls.

Dioxin is also found in some of the residuals, such as boiler ash, from our mill operations and in some solids that are removed during restoration work on our wastewater-treatment systems. These solids are handled according to federal, state and provincial regulations.

Sustainability in Action

Columbus is singing in the rain

Weyerhaeuser’s modified fiber facility in Columbus, Miss., has a lot less to worry about when it rains.

The site used to use a 10,000 gallon sump to hold wastewater and storm water. The water would have to go through a pre-treatment process that involved cycling through a scrubber and a filter before going to the local publicly owned treatment works.

“When the manufacturing process was down, the pretreatment was also down,” says Sarah McAnally Heinkel, who works at the mill. “So if we had large amounts of wastewater, there was no way to clear the sump.” Heavy rain could also trigger this problem with surges of storm water that challenged storage capacity. Wastewater would then have to be transferred to empty tanks on site or trucked offsite by a local company that used it in their manufacturing processes.

Enter the BT40 water treatment system.

Gone are the Columbus team’s worries about an over-capacity sump flooding out motors to the fiber fans. No longer do they need to find storage options for excess wastewater. The BT40 is a self-contained, batch, pre-treatment system with a 900-gallon tank where the pH of the wastewater is neutralized. Wastewater goes through a filter where solids are collected and then flows immediately to the publicly owned treatment works. The new system is not only more efficient, but more effective.

Now that’s something to sing about.

Last updated June 17, 2010.