Tex. Labor Code § 21.122

(a) An unlawful employment practice based on disparate impact is established under this chapter only if:

(1) a complainant demonstrates that a respondent uses a particular employment practice that causes a disparate impact on the basis of race, color, sex, national origin, religion, or disability and the respondent fails to demonstrate that the challenged practice is job-related for the position in question and consistent with business necessity; or

(2) the complainant makes the demonstration in accordance with federal law as that law existed June 4, 1989, with respect to the concept of alternative employment practices, and the respondent refuses to adopt such an alternative employment practice.

(b) To determine the availability of and burden of proof applicable to a disparate impact case involving age discrimination, the court shall apply the judicial interpretation of the Age Discrimination in Employment Act of 1967 and its subsequent amendments (29 U.S.C. Section 621 et seq.).

(c) To demonstrate that a particular employment practice causes a disparate impact, the complainant must demonstrate that each particular challenged employment practice causes a disparate impact, except that if the complainant demonstrates to the satisfaction of the court that the elements of a respondent's decision-making process are not capable of separation for analysis, that decision-making process may be analyzed as one employment practice.

(d) If the respondent demonstrates that a specific practice does not cause a disparate impact, the respondent may not be required to demonstrate that the practice is consistent with business necessity.