(a) If the acquisition of only part of a property would leave its owner with an uneconomic remnant, the condemnor shall offer to acquire the remnant concurrently and may acquire it by purchase or by condemnation if the owner consents.
(b) “Uneconomic remnant” as used in this section means a remainder following a partial taking of property, of such size, shape, or condition as to be of little value or that gives rise to a substantial risk that the condemnor will be required to pay in compensation for the part taken an amount substantially equivalent to the amount that would be required to be paid if it and the remainder were taken as a whole.