Wis. Stat. § 160.32: Common law and liability.

(1) Common law unaffected. Nothing in this chapter restricts or abrogates any remedy which any person or class of persons may have under other statutory or common law.

(2) No admission of liability. A response at a specific site taken by any person under s. 160.23 or 160.25 is not evidence of liability or an admission of liability for any potential or actual environmental pollution, as defined under s. 299.01 (4).