Local Oversight Program

Underground Storage Tanks

You Are Responsible When  a Leak or Spill Occurs


Owners and operators of underground storage tanks (USTs), as well as property owners, have certain responsibilities under federal and state laws should an UST leak and contaminate the environment.  These persons, called "Responsible Parties" , must report to the County's Department of Environmental Health within 24 hours any unauthorized release, spill, or overfill from an UST, and must take any needed corrective action to clean-up the contaminated site.

This web page provides an overview of the steps a Responsible Party must take once contamination from an UST is suspected or confirmed.

Step 1 -- Contaminated Discovery

If a Responsible Party suspects or knows of a leak, spill or overfill from an UST, an environmental assessment must be completed. This assessment consists of reviewing both the current and past use of the property to determine what contaminants may be present. If contamination is discovered or likely to be present, Responsible Parties are required by law to report the contamination to the County's Department of Environmental Health, Site Assessment and Mitigation (SAM) Program and to take corrective action.

Step 2 -- Corrective Action

Site Assessment
Tests will be conducted to determine the nature and extent of the contamination.   Depending upon the scope of the contamination, a number of tests on soil, groundwater and/or surface waters will be initiated.  Several phases of testing may be needed to determine the full extent of contamination.

Site Mitigation
Based on the results of the site assessment, SAM will determine if mitigation is necessary.  If mitigation is needed, an effective "clean-up" strategy or Corrective Action Plan must be developed and submitted to SAM for concurrence.

Corrective Action Plan
A Corrective Action Plan includes:

  • Assessment of Impacts:  An assessment is made of any potential environmental and public health effects of the contamination found during the site assessment.
  • Determination of Required Clean-Up Levels: State law requires varying levels of "clean-up" for water and soil, based upon risks to public health and water resources.
  • Feasibility Study: At least two methods of "clean-up" must be considered and evaluated for feasibility and cost-effectiveness.
  • Monitor and Report Effectiveness of the Implemented Corrective Action: The effectiveness of the Corrective Action Plan must be monitored, evaluated, and reported.

Communication with the Department of Environmental Health's SAM Program is encouraged at all steps in the development of the Corrective Action Plan to expedite the final review and concurrence with the Plan.

Public Notification
The Responsible Party is required to notify the public of proposed corrective action for contaminated sites. If sufficient public interest exists, a public meeting may be held at which Responsible Parties and their consultants must present their site assessment findings and their proposed Corrective Action Plan.

Step 3 – No further action

Once the Corrective Action Plan has been successfully implemented and the required level of "clean up" has been completed, no further action will need to be taken at the site. A "No Further Action letter will be issued to the Responsible Parties by the Department of Environmental Health’s SAM Division Stating that, based on available information, no further action is required at that time.

Change in Use of Site: Should the use of a site change in the future, or if additional contamination is discovered, the property owner must contact the Department of Environmental Health’s SAM Division for an evaluation of the site. At that time it will be determined if any further action is required to protect public health and environment, based on the proposed use of the site or the extent of the newly discovered contamination.

Assistance and Consultation
The County’s Department of Environmental Health, Site Assessment and Mitigation (SAM) Program oversees corrective action at contaminated sites. Staff provide consultation and technical assistance to Responsible Parties.  Responsible Parties are urged to hire private environmental consultants to assist them.

Role of an Environmental Consultant
The consultant assists the Responsible party in complying with federal and state laws. Consultant duties include:

Site Assessment

  • Develop and submit a workplan for site assessment;
  • Implement site assessment workplan and generate a written assessment report.

Site Mitigation

  • Develop and submit a workplan for site assessment;
  • Develop and submit a workplan for implementing the Corrective Action Plan;
  • Implement the Corrective Action Plan and generate a written assessment report.

Financial Assistance
The State Water Resources Control Board operates an UST Clean-Up Fund to assist eligible UST owners and operators with costs of the "clean-up" of contaminated soil and ground water. Information can be obtained from the State Water Resources Control Board's Underground Storage Tank Cleanup Fund Program web site.