(1) The inside surface of the pool, spa, or other water feature shall be constructed of materials that:

(a) are nontoxic to humans and the environment;

(b) are impervious and enduring;

(c) will provide a smooth and easily cleaned surface without cracks or open joints (excluding structural joints); and

(d) are free of any slip, trip, or other injury hazard.

(2) The surfaces within the pool, spa, or other water feature intended to provide footing for users shall have a slip-resistant surface and shall not cause injury to feet during normal use. The slant of the floor surface shall facilitate cleaning and the movement of bottom deposits to main drains.

(3) The colors, patterns, or finishes of the pool, spa, or other water feature interior shall not obscure objects or surfaces within the pool. The walls and floor shall be white or light pastel in color. In pools that are used competitively, the walls and floor shall be white, except for race lane lines and required accent colors.

(4) Earth floors are not permitted for pools, spas, or other water features.