Texas law provides that landowners have a right of action against oilfield operators for contamination of their land and groundwater supply. There are several potential causes of action, but the most discussed is "trespass." "Trespass” means an entry on the property of another without having consent of the owner. To constitute a trespass, entry upon another's property need not be in person but may be made by causing or permitting a thing to cross the boundary of the property below the surface of the earth. Every unauthorized entry upon property of another is a trespass, and the intent or motive prompting the trespass is immaterial.