contaminated

verb

1. (form-of, participle, past)simple past and past participle of contaminate

adj

1. adulterated; impure
2. made unfit for use by the introduction of unwholesome or undesirable elements.

   “A "contaminated" runway has over 25% of its surface area covered with standing water or slush (or loose snow) more than 3mm thick, or compressed snow and ice anywhere along the takeoff run or accelerate-stop surface.”