An airfoil includes an exterior wall, a triple trailing edge pin bank, and an impingement system. The exterior wall defines a first interior space. The exterior wall also includes a pressure sidewall and a suction sidewall. The impingement system is disposed within the first interior space. The impingement system includes an interior wall which defines a second interior space a plurality of impingement holes configured to channel a flow of coolant from the second interior space to the first interior space. The interior wall has an impingement hole density with a varying hole density pattern. The impingement system also includes dividing walls extending from the interior wall to the exterior wall. The interior wall, exterior wall, and dividing walls define a first and second zone coupled in flow communication. The impingement hole density is configured to separately meter flow to the first and second zones.