EE AND COWORKER WERE PREPARING TO DEPLOY GEOMEMBRANE ON THE FLOOR OF THE PON. HAD DEPLOYED APPROX. 4' OF MATERIAL AND DECIDED TO WAIT ON SANDBAGS. THE EES WERE STANDING ON THE EDGE OF THE LIN ER. THE WIND WAS BLOWING, SO DECIDED TO MOVE OFF THE LINE, WHEN A GUST OF WIND PICKED UP THE EDGE OF LINER CAUSING THE EE TO BE LIFTED OFF THE GROUND APPROX. 3' THEN FALLING BACKWARD.