Contaminated runway: A runway where more than 25% of the required field length within the width being used is covered by standing water or slush more than 0.125 in (3.2 mm) deep, or that has an accumulation of snow or ice. However, in certain other situations it may be appropriate to consider the runway contaminated. For example, if the section of the runway surface that is covered with standing water or slush is located where rotation and lift-off will occur, or during the high speed part of the takeoff roll, the effect will be far more significant than if it where encountered early in the takeoff while at low speed. In this situation, the runway might better be considered 'contaminated' rather than 'wet' only.