It seems like most people have some general idea of what trespass means. We’ve all seen signs posted that say things like “NO TRESPASSING.” Of course, these signs never seem to define what a trespass is, nor do they say exactly what the landowner intends by this message. But most people seem to have a general sense that ‘trespassing’ somehow involves walking, driving, or going onto somebody else’s property without an invitation or a legal right to do so.
Trespassing is actually a much broader concept than simply not walking onto property without a legal right to do so. “Trespass” is generally defined as the “unlawful interference with the possession of real property.” Landowners have a legal right to exclusive possession of their property. Interference with this right is often referred to as “trespass.”
In order for a trespass to occur, there must usually be some time of “physical” or “tangible” entry onto property. For example, one California case considered whether or not there could be a trespass by electric and magnetic fields arising from power transmission lines. San Diego Gas & Electric Co v. Superior Court (1996) 13 Cal. 4th 893. In that case, a homeowner filed suit against a utility because the homeowner was concerned about potential health effects of electro-magnetic field resulting from power lines. The Supreme Court held that because there was no physical “entry” or invasion into land, that therefore there was no trespass from the electro-magnetic fields generated by the power transmission lines. The Supreme Court noted that light, sound, noise, and odors likewise can’t usually cause a trespass, because when those things are present there is no physical interference with property. (However, there may be other legal remedies for such invasions of the use and enjoyment of property – but even in such situations, there will generally be no claim for a trespass). The Court noted that trespass can exist where such noise, vibration, or odors have resulted in the depositing of dust or other particles on real property. A trespass can also exist where there has actually been damage to the property.
In one case, a defendant operated a “cotton ginning mill” which caused the lawns, flowers, shrubs, window screens, hedges and furniture on the neighboring property to be coated with a thick coating of dust, lint and “ginning waste” for six months during each year. The neighbor finally got fed up, and filed a lawsuit for trespass. The Court ruled (no surprise here) that the defendant had in fact trespassed by depositing all of this dust and debris on the neighbor’s property. Many landowners might not realize that such deposits constitute an unlawful trespass. This is perhaps an extreme example, because a trespass can exist with a far smaller volume of deposited material than is described in this case. This case is reported as Kornoff v. Kingsburg Cotton Oil Co. (1955) 45 Cal. 2d 265. As far as the law is concerned, trespass may or may not involve people setting their foot on a neighboring property. If there’s even so much as a depositing of fine dust or particles, then a trespass may occur.
Correct legal analysis of whether or not a trespass occurs requires careful evaluation of applicable legal principles and is best performed by trained professionals. Legal results can vary widely from the examples given in this article. Persons concerned about trespass or potential trespass issues may not have sufficient expertise to correctly identify whether or not a trespass exists, and such person always do well to consult qualified, experience legal counsel in connection with any such questions.