30 Tex. Admin. Code § 112.216
The owner or operator shall maintain records in written or electronic format for a minimum of five years of the continuous monitoring of the sulfur content and flow rate of gases routed to either the flare or the incinerator as well as which control device was in use and of all monitoring data and emission calculations required under § 112.213 of this title (relating to Monitoring Requirements). The owner or operator shall maintain records for a minimum of five years of all testing done for monitors and copies of each performance test conducted. The owner or operator shall maintain documentation for a minimum of five years of any period that emission limits or standards were exceeded and copies of required exceedance reports submitted to the appropriate Texas Commission on Environmental Quality Regional Office.
30 Tex. Admin. Code § 112.216