All slaughterhouses shall be located on a well-drained site. All pens, coops and hutches shall be well drained so as to prevent standing pools of water. All floor areas shall be constructed of or covered with smooth concrete, tile or other impervious material and the floor material shall extend up to at least six (6) inches onto the walls. All floors shall be sloped to drain effectively. All walls and ceilings shall be covered with smooth, washable, nonabsorbent material, free from cracks, crevices and open joints. (Mont. Co. Code 1965, § 101-8.)