When a sanitary sewer improvement is required to provide excess capacity, in accordance with the provisions of section 12-521 of this part, the city/authority may participate in the construction of the facility. Such participation shall be limited to costs directly attributable to the required excess capacity. In no instance shall this participation apply to improvements necessary to meet minimum design criteria of the city/authority or Oklahoma state department of health. (Ord. 1354, 8-9-1994)