The general principles of civil liability for conduct which harms a person are that such a person must show a legal injury to a right protected by law, caused by an act of the defendant which the law regards as a wrong. The four theories of tort law most likely to be applied in a case of harm from underground waste disposal are (1) trespass, an intentional invasion of the physical property of the plaintiff; (2) negligence, the causing of harm through failure to use reasonable care to avoid injury; (3) nuisance, the use of property so as to cause unreasonable interference with the use and enjoyment of another's property; and (4) strict liability, imposed without regard to fault upon those who engage in abnormally dangerous activities. The plaintiff's remedies are damages and injunction. The plaintiff will choose that rule and that remedy most suitable to his case, most likely to be sustained by the local court, and easiest to prove. The actor has few defenses other than to attack the theory of the plaintiff for lack of (or lack of proof of) an element of his case.
The new trend in the law is toward “conditional fault” (reflected in the difference between the American Law Institute's Restatement of Torts of 30 years ago and the new Restatement [Second] of Torts), which permits desirable conduct although it carries possibilities of harm, but which requires the actor to pay if harm occurs.