X0306 4 2016-01-22 0 0001410636 American Water Works Company, Inc. AWK 0001233549 STORY SUSAN N 1025 LAUREL OAK ROAD VOORHEES NJ 08043 1 1 0 0 President and CEO Common Stock 2016-01-22 4 M 0 10559 0.00 A 48339 D Common Stock 2016-01-22 4 A 0 8219 0.00 A 56558 D Common Stock 2016-01-22 4 F 0 7554 62.44 D 49004 D Performance Stock Units 2016-01-22 4 A 0 4525 0.00 A 2015-12-31 Common Stock 4525 10559 D Performance Stock Units 2016-01-22 4 M 0 10559 0.00 D 2015-12-31 Common Stock 10559 0 D Each performance stock unit represented a contingent right to receive one share of common stock of American Water Works Company, Inc. (the "Company"), based on the Company's annual relative total stockholder return over a three-year performance period, beginning on January 1, 2013 and ending December 31, 2015. Represents the above-target earned portion of the TSR performance stock unit. In 2013, the Company granted 6,034 performance stock units, equal to the number of shares to be received if target performance was achieved. Represents the end of the performance period to which the performance stock units relate. Represents the earned portion of the TSR performance stock units, including target units granted in 2013 and above-target units earned based on TSR performance. The number of TSR performance stock units earned was 175 percent of the target. /s/ Jeffrey M. Taylor, as attorney-in-fact for Susan N. Story 2016-01-25