(a) On lots provided with a drain inlet for a unit, the drain inlet shall be not less than three (3) inches in diameter and shall be connected to an approved sewage disposal system.

(b) When drain inlets are provided, they shall accommodate a threaded or clamp-type fitting for connecting drain connectors at proper grade. The drain inlet shall be accessible at ground level. The vertical riser of a drain inlet shall not exceed three (3) inches in height above the concrete supporting slab. Drain inlets shall be gas-tight when not in use.

(c) Each drain inlet shall be protected from movement by being encased in a concrete slab not less than three and one-half (3 ½ ) inches thick and which surrounds the inlet by not less than six (6) inches on any side.

(d) In parks constructed after July 7, 2004, that contain lot drain inlets, the opening of the drain inlet shall not extend above the surrounding concrete. The surface of the concrete surrounding the drain inlet shall be smooth finished concrete and shall slope a minimum of one-quarter ( ¼ ) inch per foot from the outer edge to the inner edge of the drain inlet.

(e) Drain inlets and extensions to grade shall be of material approved for use under or within a building.

(f) The lot drain inlet shall be located within four (4) feet of the outside of the unit.