Domtar USA : Water Efficiency and Cost Reduction Are Signs of Good Water Management

Watching water move down a river can lull us into thinking it's as free as it is free-flowing. But this resource, which we share with our communities, isn't free. In recent years, we have taken a closer look at the costs of using water in making pulp and paper. Thanks to a variety of process improvements, we are seeing greater water efficiency and lower costs.

We are intentional about our water efficiency, and we return nearly 90 percent of it to its source. In many cases, the water we return is cleaner and clearer than it was originally.

'While Domtar's mills operate in areas with ample water supplies, and in most locations, we pay little to no fees to withdraw water, we don't want to fall into the trap of taking this resource for granted,' says Brian Kozlowski, senior manager for sustainability performance optimization. 'We understand water is a shared resource that we borrow from nature.'

Understanding the Full Cost of Water

The cost to pump, filter, demineralize, treat, heat, reuse and clean the water before returning it to the environment is anything but free. Our water costs are complex, comprising long-term, short-term, fixed and variable costs. And they matter, both to our bottom line and to the communities where we operate.

Our 13 pulp and paper mills are located in watersheds with unique geographies and climates, from the Southeastern United States to Canada. The land that surrounds our facilities may be forested, agricultural or urban with a range of upstream water users, from manufacturers and farmers to cities and residential areas.

All of these factors affect the quantity, quality and timing of water available, and they require us to monitor our water efficiency closely. Our mills must manage water treatment for ever-changing conditions, including:

• Turbidity related to runoff from the landscape
• Algal blooms from upstream activities that enrich surface water with nutrients
• Varying water temperatures and flows from season to season
• Weather-related events, such as flooding, storm surges and drought

'Developing our full-cost-of-water model has been a broad effort supported by colleagues in sustainability, energy and finance, in close partnership with our local manufacturing leaders,' says Kozlowski.

Water Efficiency Can Reduce Costs

Evaluating water efficiency and costs requires a long view, with several years of data. For example, some water costs, such as obtaining a wastewater discharge permit, occur once every few years, rather than annually. Water licenses and permits, as well as water testing and labor associated with water access, use and treatment, are generally fixed costs that don't change with water use.

Other costs are variable or semi-variable, areas in which water conservation efforts can offer opportunities for savings. Energy and chemical use are two of the most significant variable costs and are more directly linked to water use. As we improve our water efficiency, we can lower our costs in these areas.

Incoming water quality determines how much treatment we have to do at the start. It's no surprise that the cleaner the incoming water is, and the less of it we use, the less it costs us to prepare it for pulp and paper manufacturing.

Also, maintenance expenses are typically semi-variable costs. Generally, the more water we use, the more likely we are to wear out water-related equipment, but these costs and activities are not directly proportional to water use.

We're already working to make the most of the water we take in. It's used to wash and transport pulp, dilute and prepare process chemicals, generate steam and electricity, carry energy and raw materials throughout the mill, and clean and cool equipment.

Because of our extensive water recycling loops and focus on water efficiency, we can reuse that water an average of 10 times in the mill before we treat it one final time in our onsite wastewater treatment plants before returning it to the watershed.

By understanding the full price of water use, we're gaining more insight into improved water management. This allows our mills to reduce water risks, increase the chances of receiving funding for water conservation projects and create greater employee awareness of the benefits of water efficiency, conservation and management.

Tags: sustainability