30 Tex. Admin. Code § 210.44
A reclaimed water system not already authorized by a commission permit or other written approval, existing on the effective date of these rules, where construction began prior to June 25, 1990, is authorized under this chapter if the provider or user of such a system provides a detailed description of the system to the executive director pursuant to the notification procedures of § 210.4 of this title (relating to Notification) and the system is approved by the executive director. Such notification must occur within 90 days of the effective date of these rules. The system is authorized unless the executive director requests additional information pursuant to § 210.45 of this title (relating to Actions on Pre-existing Reclaimed Water Systems) or denies such authorization pursuant to the provisions of § 210.46 of this title (relating to Denial of Request).
30 Tex. Admin. Code § 210.44