• State Water Resources Control Board Unanimously Adopts Low-Threat Case Closure Policy for Petroleum Underground Storage Tank Sites
  • May 24, 2012 | Authors: Colleen P. Doyle; Diana Pfeffer Martin; Jill C. Teraoka
  • Law Firm: Bingham McCutchen LLP - Los Angeles Office
  • On May 1, 2012, the California State Water Resources Control Board (the “State Board”) voted unanimously to adopt a controversial Low-Threat Underground Storage Tank (“UST”) Case Closure Policy. This policy establishes criteria to determine when site closure is appropriate for low-threat petroleum UST sites in an effort to reduce costs and to increase efficiency for responsible parties and regulatory agencies. The policy is expected to make it easier for a greater number of “low-risk” petroleum UST sites to obtain closure.


    In 2009, the State Board issued Resolution 2009-0042, which stated that there were limited resources available to administer the State Board’s responsibilities and highlighted the need to direct resources toward higher priority UST cleanup cases. In response to Resolution 2009-0042, a stakeholder group composed of two Regional Water Quality Control Boards (“Regional Boards”), a local oversight agency, a water district, representatives from the Western States Petroleum Association and California Independent Oil Marketers Association, two non-governmental organization participants, and one UST consultant presented their recommendations, including a “Draft Low-Threat UST Closure Policy, 7-14-11,” to the State Board in July 2011.

    After incorporating comments from subsequent public outreach and scoping meetings, public comment periods, external scientific peer review, and a public hearing, a Final Draft Policy dated April 19, 2012 (the “Policy”) was prepared. The State Board unanimously approved the Policy at its May 1, 2012 meeting. The Policy is intended to establish consistent case closure standards across the state at low-threat petroleum UST sites. The Policy recognizes that petroleum fuels naturally attenuate in the environment, and the biodegradation of petroleum products distinguishes them from other hazardous substances commonly found at commercial and industrial sites. The State Board envisions that the Policy’s adoption will increase UST cleanup process efficiency by reducing the time and resources spent on low-threat sites, thereby re-directing resources to other sites that present greater threats to human health and the environment. Despite the State Board’s optimism, some critics argue the Policy will shift monitoring costs from responsible parties to local agencies, residents and businesses. Others argue the Policy’s criteria are vague, creating the potential for uncertainty about whether a site is appropriate for closure.

    Sites Affected

    The Policy establishes criteria to identify a subset of sites that pose a low threat to human health and the environment, meet existing state laws and State Board policies, and are otherwise appropriate for closure. The Policy is not intended to describe the conditions at all low-threat sites in California or to prematurely close petroleum UST sites. Therefore, sites in the investigation and remediation phases will typically not be eligible for closure. Rather, the Policy seeks to identify sites that present a minimal threat and, accordingly, will apply to sites in the monitoring phase. Except in rare cases involving unique attributes, sites meeting the general criteria and media-specific criteria identified by the Policy will be considered low-threat and appropriate for closure.

    Regulatory agencies will maintain responsibility for determining whether closure is suitable. After an initial statewide review, any sites not closed will be reviewed annually, or at the request of the responsible party or party conducting the corrective action, to determine whether the site meets the Policy’s criteria. The criteria in the Policy are not exclusive, and regulatory agencies may close sites that do not meet the criteria if the agency determines that the site presents a low risk based on site-specific conditions. Conversely, site-specific conditions may increase the threat to health and the environment even when the criteria are met. In those cases, the regulatory agency may determine that closure is not appropriate. Furthermore, regulatory agencies evaluating cases involving petroleum releases from equipment other than USTs, such as pipelines or aboveground storage tanks with attributes similar to those addressed by the Policy, should consider the Policy’s criteria in making a closure determination.

    Closure Criteria

    The Policy establishes the following general criteria:

    1. The unauthorized release is located within the service area of an existing public water system;
    2. The unauthorized release consists only of petroleum;
    3. The unauthorized 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;
    6. A secondary source (i.e., petroleum-impacted soil or groundwater located at or immediately below the point of the release) 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 25296.15; and
    8. Nuisance as defined by California Water Code section 13050 does not exist at the site.

    In addition, the Policy sets forth criteria specific to the following media:

    1. Groundwater — the Policy describes criteria to use to determine that threats to existing and anticipated beneficial uses of groundwater have been mitigated or are de minimis, including cases that have not affected groundwater;
    2. Petroleum vapor intrusion to indoor air — the Policy describes conditions that, if met, will assure that exposure to petroleum vapors in indoor air will not pose unacceptable health risks; and
    3. Direct contact and outdoor air exposure — the Policy describes conditions where direct contact with contaminated soil or inhalation of contaminants volatized to outdoor air poses a low threat to human health.

    If the regulatory agency determines that a site meets these closure criteria, no further corrective action will be required. The agency will notify the responsible party and require that all interested parties receive notification and, 60 days to comment, all monitoring wells and borings be destroyed, and all waste drums, piles and other remediation or investigation materials be removed and handled in accordance with regulatory requirements. Once these steps are complete, the regulatory agency will issue a uniform closure letter within 30 days from the end of the comment period.

    Next Steps and Potential Implications

    The State Board ordered the Regional Water Boards and local agencies to conduct, within one year, a review of all cases in the petroleum UST Cleanup Program using the criteria in the Policy. The findings of that review will be publicly available on the State Board’s GeoTracker website. Owners and operators of contaminated petroleum UST sites will find out whether their case meets the Policy’s closure criteria and if not the basis for keeping the case open.

    It remains to be seen whether the criteria created by the Policy will standardize the closure process, and, if so, how many UST and non-UST petroleum release sites will be closed as a result of the Policy. However, to the extent the Policy achieves some level of efficiency in addressing low risk sites, there should be benefits for both the regulated community and regulatory agencies. A standardized process across California should reduce costs and simplify the closure process for all interested parties. Regulatory agencies may also experience cost savings as sites are closed and agency resources are directed to higher threat sites.