Sec. 6. (a) The works board may add to the cost of construction of a system under this chapter and may include in the assessment against the property on which the system is constructed the incidental, inspection, and engineering costs that are authorized by the preliminary resolution and included in the estimate.
(b) The amount of incidental, inspection, and engineering costs included in the assessment may not exceed the amount of the incidental, inspection, and engineering costs included in the estimate.