Wis. Stat. § 292.19: Responsibility of persons conducting investigations.

(1) For purposes of this chapter, a person who conducts an investigation of property to determine the existence of, or to obtain information about, a discharge of a hazardous substance does not possess or control the hazardous substance or cause the discharge of the hazardous substance as the result of conducting the investigation.

(2) If the person who conducts the investigation physically causes a discharge, sub. (1) does not apply with respect to the portion of the property on which the person causes the discharge.