State Water Board staff detail Chapter 16 rewrite tightening UST construction, monitoring and closure rules

State Water Resources Control Board staff presented a comprehensive rewrite of Chapter 16 governing underground storage tanks, saying the regulations were adopted by the board on Sept. 3 and are currently under review by the Office of Administrative Law and expected to become effective Jan. 1.

Austin Lemire Batin, an engineer and project manager for the chapter 16 rewrite, said the rule package reorganizes UST requirements into 10 articles and appendices and ‘‘includes our definitions of terms, exclusions, and record keeping requirements’’ as well as the construction, monitoring and testing standards that are the ‘‘meat and potatoes’’ of the update.

The rewrite standardizes terminology and definitions. The regulations define an ‘‘abandoned’’ UST as a tank that has had no functional release detection for more than 365 days, lacks a current operating permit, is not permanently or temporarily closed under the new regulations and is not ‘‘decommissioned.’’ The rules replace vague phrases such as ‘‘above ground’’ or ‘‘below grade’’ with ‘‘buried’’ and ‘‘unburied,’’ and introduce ‘‘continuity’’ (an open, testable interstitial space) and ‘‘zone’’ (a monitored interstitial unit) as determinative concepts for secondary containment monitoring.

Staff also established three installation‑date tank categories to align with Health and Safety Code dates: Type 1 (installed before 07/01/2003), Type 2 (installed between 07/01/2003 and 07/01/2004) and Type 3 (installed on or after 07/01/2004). Austin said the definitions match the Health and Safety Code and that the categories are intended to clarify applicable testing and retrofit expectations.

Electronic submittals and recordkeeping receive clearer definitions. The rewrite defines ‘‘submit’’ to mean owner/operator filings to Unified Program Agencies…