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Underground Storage Tanks (UST)

Program Description

The Central Coast Water Board's underground storage tank (UST) Cleanup Unit provides technical and regulatory oversight for the investigation and cleanup of sites with leaks from USTs. Leaking USTs are a significant threat to groundwater and pose potential threat to human health, safety, and the environment. Therefore, California has been regulating USTs containing hazardous substances since 1983, applying federal and state laws, regulations and policies. The State Water Resources Control Board (State Board) is the designated lead regulatory agency for the development of the UST Program, regulations, and policy. In development of the UST Program, four main program elements have been identified: leak prevention program; tank integrity testing; enforcement of requirements; and cleanup of leaking tanks. Various agencies contribute and have jurisdiction over the UST program elements, including the Certified Unified Program Agencies (CUPAs) , which are the implementing agencies for the leak prevention program element. A CUPA is a local agency that has been certified by Cal EPA to implement the six state environmental programs, which include the Hazardous Materials Business Plan/Emergency Response Plan, Hazardous Waste/Tiered Permitting, Underground Storage Tanks, Aboveground Storage Tanks (SPCC only), California Accidental Release Program and the Uniform Fire Code Hazardous Materials Management Plan, within the local agency's jurisdiction. The State Board administers the Tank Tester Licensing Program to meet the tank integrity testing requirements, which are required by law. Enforcement of UST requirements is primarily conducted by the local agencies, although the Water Boards and State Board do provide assistance. The cleanup element of the program involves investigation and remediation of leaking underground tanks, under the direction of local implementing agencies and/or Water Boards.

In addition, the GeoTracker data warehouse and geographic information system (GIS) provides online access to environmental data. It is used to plot UST site and monitoring well locations and track regulatory information about UST facilities, Spills, Leaks, Investigations, and Cleanup (SLIC) sites, and public drinking water wells, and in the future will include other types of cleanup and investigation sites, including Department of Defense (DoD), Landfill, and Aboveground Storage Tank facilities. GeoTracker uses commercially available software to allow users, including the public, to access data over the Internet. Case information can be graphically displayed as a layer on GeoTracker, includes highways and roads, topographic maps, surface water boundaries, watershed boundaries, groundwater basins, and hydrologic vulnerability areas by entering a site address, partial site address, or site name.

Finally, the UST Cleanup Fund is an independent but related State Board program.

Cleanup Goals

State Water Resources Control Board Resolution No. 92-49, requires Water Boards to implement procedures to ensure that dischargers are required to cleanup and abate the effects of discharges in a manner that promotes attainment of either background water quality, or the best water quality which is reasonable if background levels of water quality cannot be restored, considering all demands being made and to be made on those waters and the total values involved, beneficial and detrimental, economic and social, tangible and intangible; in approving any alternative cleanup levels less stringent than background.

The Central Coast Region's "Water Quality Control Plan" (Basin Plan) designates all groundwater throughout the Region, except for that found in the Soda Lake Sub-basin, as having beneficial uses for domestic and municipal supply, agricultural supply, and industrial supply. Therefore, unless a discharger can demonstrate that it is infeasible, all effects of the discharge must be cleaned up as all users of the water are entitled to a supply of drinking water that is free of petroleum constituents, since petroleum is not normally found in groundwater. However, for sites where the plume is well characterized, is contained onsite, is contracting or declining in size and concentration due to contaminant attenuation, (i.e., natural bioremediation or degradation of the constituents to harmless compounds) the contaminant mass has been removed from the site to the extent practical, and historical monitoring data indicate the hydrocarbon constituent concentrations are expected to continue to decrease with time and are unlikely to reach a drinking water supply well before constituents completely attenuate, the following values are commonly used to indicate a low risk case that can be closed:

  • less than 1,000 micrograms per liter (ug/L) total petroleum hydrocarbons (TPH),
  • less than 1 ug/L benzene,
  • less than 5 ug/L methyl tertiary-butyl ether (MTBE),
  • less than 12 ug/L tri-butyl alcohol (TBA)

The TPH and MTBE values have been established based on taste and odor thresholds, not health risks; benzene value is based on the California Primary Maximum Contaminant Level (MCL), which is based on health effects data, but also contain other information relating to technical and economic feasibility of attainment in a water distribution system. The TBA value is based on California Department of Health Services (DHS) Notification Level, which is a health-based advisory level used by DHS for chemicals in drinking water that lack MCLs.

Low-Threat Closure Policy

On May 1, 2012, the State Water Board adopted a Low-Threat Underground Storage Tank (UST) Case Closure Policy (Policy). See State Water Board Resolution No. 2012-0016. The Policy was approved by the Office of Administrative Law (OAL) on July 30, 2012. On August 17, 2012, the Notice of Decision was filed with the California Secretary for Natural Resources, and the Policy became effective

Go to the State Water Board wesite for the Low-Threat Closure Policy

Addition of Materials for In-Situ Bioremediation, Chemical Oxidation, Chemical Reduction, or Tracer Test

Injection of materials to the substrate is an effective treatment technology used to reduce the levels of contaminants in the soil and/or groundwater at active groundwater cleanup sites.  A discharger must seek coverage under the adopted General Waiver of Waste Discharge Requirement for Specific Types of Discharge, Resolution No. R3-2014-0041 Attachment A, Section D.

Discharge of Treated Groundwater

The discharges of highly treated groundwater resulting from cleanup at leaking underground storage sites and spill sites requires a General Permit.  An application for the National Pollutant Discharge Elimination System Permit for Discharge of Highly Treated Groundwater to Surface Waters, Order No. R3-2006-0067, NPDES No. CAG993002 is located in the Adopted Orders Section.

Authority

The Central Coast Water Board (Water Board) is the State regulatory agency responsible for protecting the quality of groundwater and surface waters within its region. Through State laws/regulations the Water Board has authority to require submission of information, direct action, establish regulations, levy penalties and bring legal action when necessary to protect water quality. Pursuant to the Porter-Cologne Water Quality Control Act (California Water Code, Division 7), Section 13267, the Water Board may require investigation of the quality of any waters of the State within its region and, in doing so, may require the submittal of necessary technical reports. Furthermore, California Water Code Section 13304 provides that the Water Board may require cleanup of waste and abate the effects of a discharge or a threat of a discharge of waste into the waters of the State.

The UST Program's authority comes from the California Health & Safety Code , which gives local agencies the authority to oversee investigation and cleanup of UST leak sites. Some local agencies provide oversight for underground fuel storage tank cases through the County Local Oversight Program (LOP) contract with the State Board.

For more information, please contact Chris Adair of the Underground Storage Tank Cleanup Unit at 805 549-3761.