Low-Threat Underground Storage Tank Case Closure Policy

Environmental Law  

May 2012


The California State Water Resources Control Board (“State Board”) has approved a new policy that sets forth uniform criteria for closing former leaking underground storage tank (“UST”) sites where cleanup has occurred and monitoring indicates that the site is stable and ready for reuse.  The Low-Threat Underground Storage Tank Case Closure Policy (“Policy”) was unanimously approved by the State Board on May 1, 2012, and, assuming there are no legal challenges, will likely go into effect in mid-June.  The Policy is intended to provide direction to responsible parties, increase UST cleanup process efficiency, and preserve resources for the mitigation of releases posing a greater threat to human and environmental health.

The Policy sets forth eight basic criteria that must be satisfied to qualify for closure: (1) The unauthorized release is located within the service area of a public water system; (2) The unauthorized release consists only of petroleum; (3) The unauthorized (“primary”) release from the UST system has been stopped; (4) Free product has been removed to the maximum extent practicable; (5) A conceptual site model that assesses the nature, extent, and mobility of the release has been developed (this may be sourced from multiple documents); (6) Secondary source has been removed to the extent practicable; (7) Soil or groundwater has been tested for methyl tert-butyl ether (MTBE) and results reported in accordance with Health and Safety Code section 25296; and (8) Nuisance as defined by Water Code section 13050 does not exist at the site.  In addition, the site is to be evaluated based on the media impacted by the contamination (e.g., groundwater, soil, etc.).  For example, groundwater contamination must meet certain criteria based on the size of the contaminant plume.  Presumably a plume’s size would be measured from the farthest two points, but the Policy is not clear, which illustrates that while the intent of the Policy is to provide uniform and objective closure criteria, regulators will retain some discretion.  As a further example, the Policy provides that a site may be closed despite not meeting all criteria if the regulator deems it a low threat; the opposite is also true (i.e., a site may be denied closure if a site meets all criteria, but the regulator deems closure inappropriate).

The Policy requires regulatory agencies to evaluate the Policy’s applicability to sites within their jurisdiction within one year of the Policy’s implementation.  However, this does not eliminate a responsible party’s duty to apply for closure.  Additionally, the State Board has also asked that that Regional Water Boards provide an update in six months on the effectiveness of the Policy.  Thus, if applicants for closure find difficulty in obtaining closure for a site that would seem to fit within the Policy’s parameters, the next six months will provide an excellent opportunity to provide such feedback.

It is believed by some prognosticators that the Policy may allow site closure for between one-third to one-half of the 8,000 currently-open UST sites across California, which should result in the freeing-up of UST Cleanup Fund dollars for more problematic sites.  The State Board also intends to speed up the closure petition process.

The State Board’s approval of the Policy is great news to owners of UST sites where cleanup has occurred, and monitoring shows that any remaining petroleum contamination has stabilized and will not migrate into domestic or municipal water supply wells, streams, or rivers.  It is also great news to owners of UST sites that are in need of remediation funding because UST Cleanup Fund dollars may now be directed towards more challenging sites.


The information in this newsletter is not intended to provide specific legal advice. You should consult with an attorney and not rely on any information contained herein regarding your specific situation.