Technology Merit: Water


American Water (Voorhees, N.J.) for instituting biofiltration at a majority of its surface water treatment plants in the United States in 2015. Most plants use granular activated carbon (GAC) in their filters to reduce unpleasant tastes and odors in the water, but the adsorption capacity of GAC in surface water plants is generally only a few months. In biofiltration, naturally occurring bacteria are encouraged to grow on filter media and can metabolize many organic compounds, including taste and odor-causing compounds, and reduce the GAC replacement period from three or four years to 10 years or more. In the company-wide effort, 22 of American Water’s 32 plants with GAC are in some level of testing: Savings could exceed $4 million a year and negate the need for replacing over 3.5 million pounds of GAC.