45-319. Exception; preemption A. The requirements of this article do not apply to any plumbing fixture that is documented to have been purchased by a plumbing wholesaler, retailer or end user and that is actually located in this state before January 1, 1994. B. An ordinance adopted by a county, city or town relating to water conserving low-flow plumbing fixtures is not preempted by this article to the extent that the ordinance sets forth requirements that are at least as restrictive as the requirements of this article or regulates fixtures that are not specified in this article, but any such ordinance is preempted to the extent that its requirements are less restrictive than the requirements of this article.
Arizona Legal Code