In the early 1980s, serious groundwater contamination incidents arising from leaking underground storage tanks (USTs) prompted federal and state lawmakers to issue standards for UST construction, installation, and removal, and to require the registration and monitoring of USTs. In 1984, Congress adopted a national program to regulate USTs storing petroleum and hazardous substances (“federal UST Law”). The US Environmental Protection Agency (EPA) creates national standards, which are implemented under delegation by states, the District of Columbia, and territories). The remainder of this note summarizes federal UST requirements; states can generally establish and administer stricter requirements.
Which tanks are regulated as USTs?
The Federal UST Law deals with USTs that store petroleum and other hazardous substances, but not hazardous wastes (which are regulated under the Resource Conservation and Recovery Act (RCRA)).
- Underground storage tanks
The Federal UST Law regulates individual USTs and complete UST systems, including piping and monitoring. A tank is regulated as “underground” if at least 10% of the total capacity of the entire UST system (including piping) is below grade. However, the Federal UST Law and EPA regulations exempt the following from the definition of USTs:
- farm and residential fuel tanks with a capacity of 1,100 gallons or less
- tanks storing heating oil for onsite use
- septic tanks
- pipeline facilities associated with oil or gas production and gathering activities
- surface impoundments, lagoons, pits, and ponds (generally regulated under Clean Water Act)
- storm water and wastewater collection tanks (generally regulated under CWA)
- flow-through process tanks
- tanks that are on or above the floor inside underground areas
EPA’s regulations also exclude the following:
- UST systems holding hazardous wastes regulated under RCRA
- wastewater treatment tank systems that are part of a wastewater treatment facility regulated under CWA
- equipment or machinery containing regulated substances for operational purposes, such as hydraulic lift tanks and electrical equipment
- UST systems with a capacity of 110 gallons or less
- UST systems with a “de minimis concentration” of regulated substances
- emergency spill or overflow USTs that are “expeditiously” emptied after use
- wastewater treatment tank systems
- USTs containing radioactive materials regulated under the Atomic Energy Act
- UST systems that are part of emergency generator systems at nuclear power plants
- UST systems with field-constructed tanks
Petroleum and hazardous substances
Regulated contents of USTs consist of petroleum and “hazardous substances,” which include the following:
- gasoline and other petroleum products
- substances for which reportable quantities (RQs) have been established under federal Superfund to define release reporting responsibilities
- toxic and nonconventional pollutants (also called “priority pollutants”) regulated by the CWA
- any other hazardous substance designated by EPA.
How are USTs registered with regulators?
Owners/operators of new USTs must register their tanks with EPA or the state UST agency at least 30 days before beginning service, by submitting EPA’s “Notification for Underground Storage Tanks” form or an equivalent state form. (All USTs in service at any time since January 1, 1974, should have been registered on a state inventory mandated by the Federal UST Law.) Sellers of USTs must notify buyers of these registration requirements.
What technical standards apply to UST system installation?
EPA provides detailed technical standards for UST system installation and operation, which vary with the type of UST system and the substances it stores. New UST systems must meet applicable standards as of their installation, and new and existing UST systems have been subject to deadlines for upgrades. EPA has expanded these requirements several times. Standards for both new and existing UST systems have been amended a number of times since the first rules became effective December 22, 1988:
- USTs and associated underground piping must be product-tight, compatible with the substance stored, and corrosion resistant.
- USTs must have spill and overfill protection (both technical (hardware) and procedural (monitoring).
- USTs and associated piping must have leak detection provisions (both technical and procedural).
- USTs must provide secondary containment for hazardous substances and petroleum.
- UST systems that dispense products must include under-dispenser containment.
- UST systems must be installed in compliance with applicable industry codes and manufacturer’s directions. Installers must meet licensing and certification standards.
- installer or agency must certify that UST/equipment were properly installed (on EPA’s Notification for Underground Storage Tanks form)
What technical standards apply to UST system operation?
EPA’s regulations impose “General Operating Requirements” covering spill and overfill control procedures, corrosion protection, compatibility of the UST system and contained substances, and. permissible repairs to USTs and piping, including secondary containment. Leak detection methods must have a probability of detection of 0.95 (i.e., the method must be capable of correctly indicating that a leak has occurred 95 times out of 100). EPA regulations also require UST owner and operator record keeping and reporting to demonstrate compliance, including monitoring and self-inspections.
EPA also requires periodic testing of spill prevention equipment and containment sumps used for interstitial monitoring. EPA requires periodic inspection of overfill prevention equipment, and periodic walkthrough inspections of general operations and maintenance activities, as well as performance of manufacturer-required testing.
EPA requires operator training, for each of the following three categories of personnel:
- persons with primary responsibility for on-site operation and maintenance of UST systems (Class A)
- persons with daily on-site responsibility for the operation and maintenance of UST systems (Class B)
- “daily, on-site employees” with primary responsibility for addressing emergencies presented by a spill or release (Class C)
What release reporting and corrective action requirements apply?
Most releases from UST systems must be reported to regulatory agencies. A release is defined as “any spilling, leaking, emitting, discharging, escaping, leaching or disposing from an UST into groundwater, surface water or subsurface soils.” Two types of releases (spills and overfills) need not be reported if they are completely cleaned up within 24 hours and are below the following threshold reporting quantities:
- for petroleum products. 25 gallons
- for other hazardous substances, the RQ established by EPA under the Superfund law (CERCLA)
Corrective action requirements apply after releases, varying with the extent and location (e.g., into water or not).
What closure requirements apply?
When USTs are removed from service they must be closed properly to prevent future releases into the environment. UST regulations establish rules for both temporary (no longer than 12 months) and permanent closure, including requirements when converting an UST system from storage of regulated substances to other substances.
What financial responsibility requirements apply?
The Federal UST Law requires owners and operators of USTs storing petroleum products to demonstrate financial responsibility sufficient to cover cleanup costs in the event of a leak. USTs storing other regulated hazardous substances are not addressed by these requirements since the federal Superfund law covers cleanups involving these substances. Federal and state agencies are exempt. Financial responsibility must be met when each UST is installed, and maintained continuously thereafter.
Financial responsibility limits apply in two ways (on a “per-occurrence” and an “aggregate” basis; akin to insurance). Amounts vary depending on how many USTs an owner or operator has. The per-occurrence amount required (for any single cleanup) is:
- for owners/operators of USTs in petroleum marketing facilities or USTs that handle more than 10,000 gallons per year—$1 million
- for all other UST owners/operators—$500,000
- Aggregate amounts (for all cleanups for which the owner and operator may be responsible) are as follows:
- for owners/operators of 1 to 100 USTs—$1 million
- for owners/operators of 101 or more USTs—$2 million
Many states have created funding mechanisms providing these coverage amounts, and require owners and operators to participate.
What administrative and enforcement requirements apply?
EPA’s regulations establish record keeping, monitoring and self-inspection, and reporting requirements. They also provide for agency inspections, and for enforcement for violations and to ensure corrective action.
What happens next?
The Federl UST Law and EPA’s regulations have been stable for a number of years, and requirements for upgrading existing UST systems have passed. However, states can and do revise their requirements from time to time. An organization with regulated UST systems should be in compliance, but self-evaluation of ongoing equipment and operations is prudent.
Self-assessment checklist
Does the organization own or operate any storage tank systems that are subject to regulation as UST systems (under EPA’s requirements or state requirements)?
If so, has the organization evaluated the construction and operation of each UST system, to ensure all comply with applicable requirements?
Has the organization taken any UST or UST system out of service since 1988?
- if so has the system been “closed” in compliance with applicable requirements?
- If so, has the site been evaluated for contamination and subjected to any applicable corrective action?
Where can I go for more information?
- EPA
About the Author
Jon Elliott is President of Touchstone Environmental and has been a major contributor to STP’s product range for over 30 years.
Mr. Elliott has a diverse educational background. In addition to his Juris Doctor (University of California, Boalt Hall School of Law, 1981), he holds a Master of Public Policy (Goldman School of Public Policy [GSPP], UC Berkeley, 1980), and a Bachelor of Science in Mechanical Engineering (Princeton University, 1977).
Mr. Elliott is active in professional and community organizations. In addition, he is a past chairman of the Board of Directors of the GSPP Alumni Association, and past member of the Executive Committee of the State Bar of California's Environmental Law Section (including past chair of its Legislative Committee).
You may contact Mr. Elliott directly at: tei@ix.netcom.com