Optimizing Water Use
As part of our commitment to responsible environmental stewardship, we engineer our facilities to run as efficiently as possible. That means that wherever we can, we minimize potable water use and wastewater discharge. In addition to benefiting the environment, these efforts frequently help us save money.
All thermal power plants—including our EfW facilities—use water to generate electricity. In the boiler, water is heated to generate steam, which runs the turbine to generate electricity. Most of this water is condensed and reused in the process of producing power. At some of our plants, we also generate steam that we export to communities and local businesses. While steam generation is a very efficient use of the waste resource, it can increase water consumption because the condensed water produced by the steam we export may not be returned to the facility to produce additional steam.
Water Consumption by Source
Our total water use has been fairly steady over the last three years; however, we are increasingly using stormwater and other nonpotable water sources in our operations. For example, alternative water sources, including reclaimed wastewater (which now makes up 24 percent of our water consumption, up from 11 percent in 2007), saline aquifer water and once-through cooling discharge water made up 35 percent of our 2016 water consumption.
In addition to optimizing our water consumption, we also minimize our wastewater discharge, using water internally to the extent possible. A total of 17 of our facilities are zero-process water discharge, meaning that only sanitary wastewater is discharged to the local wastewater treatment plant.
|Total Water Use (millions of gal.)||9,038||9,193||9,129|
|Percent alternative (nonpotable) water||29.8%||35.6%||35.3%|