Hazardous Waste Program

Changes to the Underground Storage Tank Regulations

In 1985, the Environmental Protection Agency created the Office of Underground Storage Tanks to carry out a Congressional mandate to develop and implement a regulatory program for underground storage tank, or UST, systems. In 1989, Missouri enacted statutes to create the Missouri Department of Natural Resources Underground Storage Tank regulations and program. Since 1989, the regulations have not been substantially changed or updated to reflect the many changes and improvements to underground storage tanks, piping, release detection methods and other equipment.

The underground storage tank regulation revisions have been published in the Nov. 30, 2011 revision of Missouri’s Code of State Regulations.

The Final Orders of Rulemaking for these regulations were published in the Nov. 1 Missouri Register.

If you have questions regarding these regulations, contact Heather Peters of the Hazardous Waste Program at 800-361-4827 or 573-522-5665 or by email, heather.peters@dnr.mo.gov.

Webinar - The department held a webinar, or online presentation, Nov. 9 to explain the new regulations and their applicability.

• Video of the Webinar
• Presentation

Note: The Missouri Risk-Based Corrective Action, or MRBCA, regulations for underground storage tanks were not part of this rulemaking process.

These regulations are now in effect!

The Environmental Protection Agency is proposing changes to the UST regulations. For more information or to provide comments or feedback, please visit their Web page on the proposed underground storage tank regulations.

Upcoming Changes

• Clarifications and Definitions
  • Once an owner brings a tank in operation (meaning that they begin dispensing fuel or using the tank for its intended purpose),the owner must provide and maintain proof of financial responsibility for any tank that is in use (contains product).
    
    The term “temporary closure” has been removed. A tank is either in use or it is empty. Empty and out of use are equivalent and both mean the tank has been emptied to less than one-inch of liquid remains.

    The regulations now clarify that “routinely” contains product does not mean the piping must continuously contain product. Remote fill lines, used oil tank lines, other gravity feeds routinely contain product, even though they do not continuously contain product. Piping that routinely contains product must be cathodically protected if warranted (e.g. if the piping is steel, it must be cathodically protected). The piping must also be monitored for leaks (unless it is gravity piping or a remote fill line). Vapor recovery lines and vent lines do not routinely contain product.

    Definitions are provided for the regular testing requirements (annual means every 365 days, triennial means every 1,095 days, monthly means every 30 days).

    All metal piping that leaks must be replaced; the entire electrically continuous run of metal piping must be replaced, not just the leaking portion.

• New UST system installations
  • The new installation requirements will now apply to the installer. Installers must:
    • Notify the department at least 30 days prior to beginning an installation (new installation notifications expire after 180 days).
    • Comply with PEI RP 100 or API RP 1615 and the manufacturer(s)’s installation guidance, practices and instructions.
    • Comply with all manufacturer certification or training requirements for equipment, including, but not limited to, tank, piping, automatic tank gauge, line leak detector or interstitial sensors.
    • Have proof of financial responsibility on file with the Missouri Department of Agriculture.
    • Pre-test the tanks prior to installation in accordance with the manufacturer and PEI 100 or API 1615.
    • Test the entire system (0.1 gallon/hour leak threshold) prior to bringing the system into use.
    • Conduct an approved form of release detection if the tank is ballasted with product (if ballasted with water, release detection is not necessary).
      

    New installation restrictions (as of January 1, 2012):

    • Ball float valves may not be installed for overfill prevention. If they are to be installed for any other purpose, they may only be installed above 98 percent of the tank’s capacity.
    • Containment sumps must be installed at:
    • Tank top areas (submersible turbine pump areas or suction piping-tank top junctions).
    • Sub-dispensers.
    • Piping transition/ball valve locations (e.g. manifold piping ball valves, piping unions or splices)

    The department also has the authority to shut down an installation that is not being conducted in accordance with the manufacturer(s)’s written procedures or guidance or is not in compliance with PEI RP 100 and API RP 1615. The shutdown may be restricted to the portion of the installation in question. The shutdown will be released upon approval by: a) the equipment manufacturer (if appropriate); b) the tank owner/operator; or c) the department.

     The owner of the new underground storage tank system must register no later than 30 days after bringing the tank into operation (dispensing fuel or using the product for its intended purpose).

• Cathodic Protection and Interior Lining systems
  • Cathodic protection system testers must be certified (current at the time of the test) by either: NACE International; Steel Tank Institute (sacrificial systems only); or ) International Code Council. More information on allowable NACE certifications, is available on EPA's website.

    Cathodic protection tests must include:

    • Tester, certification and date.
    • Testing standard used.
    • System readings (for impressed current systems, tests must also include the instant off and the decay values, if using the 100mV depolarization).

    For additional guidance on cathodic protection system test reports, please refer to the department’s checklist of information needed to review a cathodic protection system test.

    Owners/operators must maintain a log of the rectifier readings. These logs must now include relevant system data (e.g. green or red light, voltage or amperage meter readings or hour meter readings). If any of these readings change, the owner/operator must investigate and confirm that the cathodic protection system is still operating properly and providing adequate protection for the steel system components. While you are not required to use any specific form for this rectifier log, here is an example of an acceptable form.

    An integrity test, which evaluates the actual thickness of the steel shell, must be conducted if:

    • The cathodic protection system has been off, unhooked or damaged for more than 90 days.
    • The system failed during a routine test and was not adequately repaired or re-tested with passing readings within 90 days.

    The department may consider written requests for extensions.

    The interior lining of a steel tank may not be repaired, replaced or re-lined without first conducting, and passing, an integrity assessment of the tank shell.  All integrity assessments must include actual steel shell thickness readings.
    
    All lined tanks, whether lined for upgrades, repair, or compatibility, must be routinely inspected, maintained, and repaired, if warranted.  The tank must be inspected within 10 years of the initial lining and every five years thereafter, regardless of whether or not the tank is re-lined. (A tank is not granted another 10 years before inspecting the interior lining simply because the tank was re-lined.)

    Cathodic Protection Test Reports presentation

• Spill and Overfill prevention equipment
  • All deliveries must use a “lock-on” delivery connection, unless the department has approved a written, alternative delivery plan that adequately prevents spills and overfills.
    
    Ball float valves may not be used with safe suction systems, suction systems with check valves that are not completely contained within a building, with any open vapor release port (e.g. open tank top fittings or co-axial drop tubes) or pressurized deliveries. Ball float valves may not be installed on any underground storage tank system after January 1, 2012 for overfill prevention and may only be installed for alternative purposes if the ball float valve is installed above 98 percent tank capacity and proper overfill prevention equipment is in use.

• Release Detection
  • All release detection equipment (except for manual measuring sticks used for inventory control or statistical inventory reconciliation) must be approved by the National Work Group on Leak Detection Evaluations, or NWGLDE.  All release detection equipment must not only be operated and maintained in accordance with the manufacturer’s requirements, but also in accordance with the NWGLDE certification.

• Statistical Inventory Reconciliation, or SIR
  • Statistical Inventory Reconciliation has been approved as an “other” or alternative release detection method for years, but is now officially outlined in the new regulations. To properly conduct SIR, owners/operators must:
    • Take readings to at least the nearest 1/8th inch (using an automatic tank gauge meets this criteria).
    • If using a tank stick to take measurements, a drop tube must be installed.
    • If using a tank stick, the correct tank chart must be used for converting the height reading to gallons.
    • Be able to accurately measure the full range of the tank height.
    • Check for water at least once every 30 days.
    • Compare delivery reports to pre- and post-delivery measurements.
    • The SIR vendor or program must be approved by the National Work Group on Leak Detection Evaluations.
    • Conduct SIR in accordance with the NWGLDE certification and the manufacturer’s protocol.
    • The monthly data must be submitted, evaluated and reported by the 15th of the following month (e.g., June’s data must be submitted to the vendor or input in the software program, evaluated, and the final report back to the owner/operator no later than July 15).
    • Retain all supporting data, including the daily inventory, sales, deliveries, overages/shortages, monthly detailed reports and exception information, if applicable.
    • Evaluate independent tank systems separately, even if they contain the same products. Manifolded systems are typically evaluated as one system.

• High-throughput facilities
  • High-throughput facilities are those facilities with at least one underground storage tank system (a single tank or a manifolded tank system) through which more than 800,000 gallons of product is dispensed or used per month.  The following requirements apply only to the high-throughput system or systems.  The high-throughput tank system must be monitored for leaks using either:
    • Interstitial monitoring - Continuous, electronic interstitial monitoring may be used for any double-walled or secondarily contained tank or piping system. Please note, the secondary containment or outer wall must be able to contain any leak from the inner wall with the interstitial monitoring system able to detect any failure of the inner wall. In addition, the secondary containment or outer wall must also prevent water intrusion or water interference from affecting the interstitial monitoring system.
    • Vapor monitoring - Must be compatible or approved for the product stored (standard vapor monitoring is not approved for diesel, but chemical marker testing is). This monitoring must be conducted every 15 days.
    • Continuous In Tank Leak Detection Systems, which must include a continuous reconciliation feature (SCALD or CSLD testing is not sufficient). This method of release detection conducts constant evaluations to determine if a system is leaking and to monitor inventory leak calculation trends.  A Continuous In Tank Leak Detection System is more precise and is specifically designed for high-throughput facilities.
    • Another method approved by the department that is appropriate for high-throughput facilities.

    Please note, these requirements apply only to the high-throughput tanks and do not necessarily apply to all tanks at a facility.

• Emergency Generator tanks
  • The new regulations require tanks that store fuel for emergency generators to be monitored for leaks. Owners/operators will have to conduct monitoring just like any other tank regulated under the Missouri Underground Storage Tank tank law and regulation. Most of these tanks are already conducting a method of release detection, specifically, an automatic tank gauge. For additional information about release detection options, please review EPA’s guidance document Straight Talk on Tanks: Leak Detection Methods For Petroleum Underground Storage Tanks And Piping or visit their release detection Web page.
    
    Pressurized piping connected to emergency generators, though, may use interstitial monitoring (e.g. containment sump sensors) with an alarm in lieu of an automatic line leak detector. An alternative option is an electronic line leak detector, equipped with an alarm but not the shutdown function. A mechanical line leak detector is not recommended on pressurized piping connected to an emergency generator tank as it could shutdown fuel flow at a critical moment.

• Out of use tanks and permanent closure
  • Any tank that is in use (contains product) must comply with all related underground storage tank regulations (financial responsibility, release detection, corrosion protection, including cathodic protection and lining requirements). Once a tank is brought into operation for the first time, “in use” is based solely on whether the tank contains product and is not related to whether or not product is being used or dispensed.
    
    Out of use means that the tank has been emptied so that no more than one inch of product remains, or that no more than 0.3 percent by weight of the total capacity remains.

    The cathodic protection system/interior lining on an out of use tank does not have to be maintained. Please note, an owner/operator has the following options for their out of use tank(s):

    • Stop maintaining and inspecting the cathodic protection system or interior lining (only recommended if the owner/operator does not intend to ever use the tank again).
    • Maintain the cathodic protection system or interior lining (conduct all scheduled inspections and associated repairs, ensure the cathodic protection system is on, functioning and is being monitoring).

    If an owner/operator chooses option one but then opts to reopen the tank, the tank must pass a tank assessment/tightness test.  If the tank is steel:

    • Lining: The lining must either pass inspection or be repaired/reinstalled.
    • Cathodic Protection: The cathodic protection system must be redesigned or re-evaluated and re-energized by a cathodic protection expert.

    Once a tank is taken out of use, the following steps must be taken:

    • Within one year/12 months, a site assessment must be conducted.
    • Within five years of being taken out of use (not associated with the date of the assessment), the tank must be permanently closed.

    A site assessment must include sampling of soils and groundwater in the areas where a release would have most likely occurred.  Soil borings should be advanced on each side of the underground storage tanks, piping, and pump islands/dispensers in accordance Section 5 of the Risk Based Corrective Action Process for Petroleum Storage Tanks, or another process approved by the Department.  These sampling points should be advanced so that groundwater samples can be collected, if groundwater is encountered. 

    Please note, sample data conducted for the site assessment may be used for the closure report upon permanent tank closure only if:

    • The tank has not contained any regulated substances since the data was collected.
    • No new or additional signs of a release have been reported or found.
    • A written request to use the data as part of a closure plan has been approved by the department.
    • Additional soil samples underneath the tanks are taken during tank removal. 
    • The permanent closure must be completed in accordance with Section 4 of the Risk Based Corrective Action Process for Petroleum Storage Tanks, or another process approved by the Department.  Please be aware that additional sampling and requirements may be needed to complete the closure of the tanks. 

    Permanent closure of the tank must be conducted within five years of the date the tank was emptied. 

    The regulations also clarify that all regulated tanks that have not been permanently closed, even those out of use prior to 1989, must still be permanently closed in accordance with the regulations. For tanks out of use prior to August 28, 1989, the person(s) who owned the tank immediately prior to its being taken out of use is/are the person(s) responsible for complying with the closure requirements.