The defendant need not answer the petition. Wehrum v. Village of Lincolnwood, 91 Ill.App.2d 418, 421, 235 N.E.2d 343 (1968). The only issue raised by the petition is the amount of compensation due the defendant.

Plaintiff contends that the doctrine of election of remedies does not bar an action for trespass which antedates condemnation. The case upon which plaintiff heavily relies for support is Wehrum v. Village of Lincolnwood (1968), 91 Ill. App.2d 418, 235 N.E.2d 343, appeal denied (1968), 38 Ill.2d 630. In that case, the local municipality had converted plaintiffs' private property into a playground in 1960, but the condemnation proceedings were not instituted until 1965.

The Dixons argue that injury to property not necessary to the construction and operation of a public service for which an easement is taken gives rise to a cause of action separate from the eminent domain proceeding. See, e.g., Grainland Farms, Inc. v. Arkansas Louisiana Gas Company, 11 Kan. App. 2d 402, 722 P.2d 1125 (1986); Wehrum v. Village of Lincolnwood, 91 Ill. App.2d 418, 235 N.E.2d 343 (1968). See also 6A J. SACKMAN, NICHOLS, THE LAW OF EMINENT DOMAIN § 28.31, at 28-93 (rev. 3d ed. 1990).

It is certainly possible that a landowner may suffer damages from a trespass which would not be compensable as part of a taking. See Ancarrow v. City of Richmond, 600 F.2d 443, 445 (4th Cir. 1979); Wehrum v. Village of Lincolnwood, 91 Ill. App.2d 418, 235 N.E.2d 343 (1968). Therefore, we conclude that the district court erred in holding that the condemnation award precluded the bringing of any trespass action.

This is the only issue triable by the jury in such a case. ( Sanitary District v. Johnson (1931), 343 Ill. 11, 174 N.E. 862; Wehrum v. Village of Lincolnwood (1968), 91 Ill. App.2d 418, 235 N.E.2d 343.) Thus, it has been held that in order to be admissible in a condemnation proceeding, evidence as to damages to land not taken by petitioner must be specifically related to a diminution in the fair market value of that land. ( Department of Transportation v. Jones (1976), 44 Ill. App.3d 592, 358 N.E.2d 402.

The whole purpose of the condemnation proceeding is to satisfy the constitutional and statutory requirements that property not be taken without due process of law and that just compensation be awarded therefor. ( Illinois Cities Water Co. v. City of Mt. Vernon (1957), 11 Ill.2d 547, 551, 144 N.E.2d 729; see also Commissioners of Lincoln Park v. Schmidt (1944), 386 Ill. 550, 555, 54 N.E.2d 525; Wehrum v. Village of Lincolnwood (1st Dist. 1968), 91 Ill. App.2d 418, 420, 235 N.E.2d 343.) Had plaintiffs in the trial court sought to upset the ordinance or challenge the rezoning, we would agree that plaintiffs were collaterally attacking Judge Healy's order.