(a) It is hereby found and determined by the Legislature that in fulfilling their prescribed purposes and exercising their powers, including the purpose of promoting, developing and advancing the business prosperity and economic welfare of the county for which created by acquiring lands and other real property to be furnished by lease, sale or other disposition as industrial sites, county development authorities are performing essential public purposes; that the performance of such essential public purposes are frequently impeded, unduly delayed, or wholly frustrated by imperfections in the title to essential land and other real properties, by lost heirs or widely scattered owners of undivided interests in essential lands and other real properties and by owners of relatively small but essential parcels of a proposed land development site who refuse to sell their land or other real property to the county; and, that the exercise by county development authorities of the right of eminent domain within the limitations herein provided is therefore necessary and appropriate to achieve the said public purposes of county development authorities.

(b) Any county development authority heretofore or hereafter created by a county commission pursuant to the authority of this article is hereby authorized and empowered to exercise the right of eminent domain if an order of such county commission authorizing exercise of the right of eminent domain as to any proposed acquisition is first made and entered and at least three fourths of the entire tract has either been purchased, optioned, or is under contract to be purchased: Provided, That prior to the issuance of the order by the county commission, it shall hold a public hearing on the public necessity of the exercise of eminent domain and shall cause a Class II legal advertisement to be published in accordance with the provisions of section two, article three, chapter fifty-nine, prior to the hearing: Provided, however, That a separate hearing must be held and a separate order promulgated for each parcel over which the authority wishes to exercise the power of eminent domain: Provided further, That the right of eminent domain shall not be exercised to acquire real property which exceeds one fourth of any land development site proposed by the county development authority, and the aforesaid order of a county commission shall specifically state the anticipated size of the entire site with respect to which the exercise by a county development authority of the right of eminent domain is authorized.