New Testing Methods for Containment Sumps at Refined Petroleum Facilities

Underground storage tanks (USTs) that contain a wide variety of materials, including regulated liquids such as gasoline, aviation fuel, diesel and other types of regulated liquids, are required under federal and state regulations to provide various compliance documentation and periodic tests. One of these requirements is that tanks and piping installed after April 11, 2016 (EPA) must have secondary containment and interstitial monitoring. Further, secondary containment sumps for dispensers, submersible turbine pumps, transition and spill are required to be tested for integrity at least once every three years.  Furthermore, some containment sumps (Spill Buckets) must be tested for integrity annually. 

Current Potential Test Methods

There are now three possible methods to test containment sumps. All three methods should only be conducted by a qualified technician and in some cases, licensing by the Authority Having Jurisdiction (AHJ) for the tester and company. The results of the test should be certified by the testing company and/or qualifications of the tester by using the appropriate equipment and following the protocol per test method or manufacturer requirements. Each test method may have advantages or disadvantages for your specific locations. This summary is merely a discussion of the test methods and the advantages and disadvantages for your review. The following briefly describes each test method.

PEI/RP1200-17 Hydrostatic Test

RP1200-17 is provided by Petroleum Equipment Institute and is a Recommended Practice accepted by EPA and State Regulatory agencies to test spill buckets, Submersible Turbine Pump (STP) sumps, Under Dispenser Containment (UDC) sumps and Transitional sumps. The Recommended Practice describes the testing method as a hydrostatic test. Typically, a volume of water is placed in the containment sump 4 inches above the highest side penetrations or to the highest sidewall seam in the sump, measured and then remeasured after a period of one hour. If there is no loss greater than 1/8 inch of the test liquid, then the containment system is determined to have passed the integrity test. However, the water testing fluid is considered contaminated since it was placed in a containment vessel used to catch releases of petroleum products and other liquids.  Thus, the water testing fluid must be disposed of in an environmentally safe manner. CONTACT www.pei.org for a copy of RP1200.

Advantages

Widely accepted by both federal and state agencies

Method meets all requirements of the federal and state regulations for complete testing of the sides, bottom and all penetration points

Does not require the additional testing of the sensor for the hydrostatic test

Simple test equipment (ruler accurate to within 1/16”, one-hour time-measurement device, pump, water storage container

Some states allow the “re-use” of water to test multiple containment sumps

Can be used to test any spill bucket or containment sump

Test method has been in use for years as an industry standard

Repairs can sometimes be made prior to testing by visually identifying areas of concern before the initial test

Disadvantages

Method to transport test liquid (water) safely, and means to pump water into and out of the containment sumps can be costly

The sensor, if present must be removed in some manner before beginning the test

Test boots must be made tight before performing the test

Water disposal is costly

Test can be very time consuming when testing several sumps at a facility (one hour per test)

Spills of contaminated “re-use” water can increase the environmental clean-up for the tester and owner

Transporting and placing contaminated water from a previous test location impacts the second, third, etc owner’s location and increases environmental liability of cleanup

Pumping test liquid into a sump too quickly can cause structural damage to some containment sumps

Repairs can be rather time consuming and require another test to indicate a passing result

 PMAA Alternative “under-fill” Test

The Petroleum Marketers Association of America has presented an alternative method that has been accepted by the EPA. Each state agency must determine if they will accept or modify an alternative method. This alternative method is an “under-fill” hydrostatic test that only places enough water in a containment sump (STP, UDC, Transitional) to test the sensor which is connected to an automatic tank gauge system. The sensor must be able to positively shut down the STP and/or the Dispenser. The alarm must be addressed by the owner or employee of the owner. The test liquid must be placed in the containment sump to a depth determined by the manufacturer of the sensor system that will trigger the sensor’s alarm. The alarm must also trigger a positive shut down of the STP and/or Dispenser. The Federal and State regulations require liquid-tight sides, bottom and all penetration points. This alternative method does not address how to test for this requirement. The test is to determine the accuracy of the electronic sensor. Although the amount of water used is less than the hydrostatic test, it can still be rather expensive. CONTACT www.pmaa.org for more information on this method.

 Advantages

EPA has accepted this alternative method with conditions stated

Some state agencies have accepted this alternative method with conditions stated

Less waste water to dispose (only about 10-20 gallons per containment sump)

Test equipment is simple (tools to work on sensors, ATGs, measuring and timer devices, water pumping and storage container

Sensor and positive shut down are tested

Less expensive water disposal than hydrostatic test

Repairs can sometimes be made prior to testing by visually identifying areas of concern before the initial test

Retesting after repairs is quicker since there is less test water to remove

Disadvantages

This test method is not accepted by all state agencies and is strictly an “alternative” method

This method does not test the Spill Bucket which is still required to be tested annually

This method does not test the integrity of the sides, bottom and all penetration points

All the expense and environmental impact with transporting, re-using and spilling test water are still present in this test method

Faulty equipment (sensors, ATG, etc.) can cause unnecessary automatic shutdown of the pump and/or dispensers which is not customer friendly

Failure of the sensor can cause catastrophic environmental impact since it is the only thing actually tested and no test is conducted to determine the condition of the sides, bottom or any penetration points

Pumping test liquid into a sump too quickly can cause structural damage to some containment sumps

Repairs can be rather time consuming and require another test to indicate a passing result

Test boots must be made tight before performing the test if they are below the level of the test liquid

Dri-sump? Containment Tightness Testing

This is the only test method with an actual EPA 3rd Party evaluation.  The Dri-sump? equipment and method uses no water, creates no waste and can be conducted in as little as 10 seconds. (Trademarks and Patent-pending US and all foreign) This method can quickly and safely test any open or closed top containment sump or tank, storage vessel, vault, or any other type containment located above and below ground to 0.10gph standard with no waste by-products and without water. Further, the method can test hazardous or non-hazardous containment sumps, vessels, tanks, vaults, etc. as listed including but not limited to under dispenser (UDC), submersible turbine pump (STP), transition, spill containment (spill bucket), and any other type containment sump or tank/vessel.

This method is capable of testing dry secondary containment for piping and tanks. It can also be used to test the ullage portion of any tank or vessel.

Although testing with heavy gases and/or vapor aerosols has been an industry standard in locating leaks in underground utility lines, clean rooms, aircraft fuselages, biological containment cabinetry and more, it is now available for all types of containment sumps. For this discussion, we will only discuss testing with heavy vapor fog. The test method requires “filling” the entire containment sump with heavy vapor fog. This “fog” is made from a proprietary formula of chemicals which are all food grade and safe. A small Vapor Stimulator Tube (VST) is placed directly into the soils adjacent to the sump and resembles a miniature well screen. A negative pressure is pulled on the VST. Leaks in the sump allow the heavy fog to enter the soils due to the negative pressure applied to the VST. Fog particles that are microns in size then enter a “view chamber” with a laser. The fog particles can easily be seen by the laser and cause an obvious “laser line” to activate which indicates the sump fails the test. If there is no laser line and only the laser “dot”, there is no leak at the time of the test. The heavy fog dissipates in about 5 to 10 minutes. Most leaking areas can then be identified by setting the equipment into positive pressure mode. This test is probably the least expensive since there are no waste by-products to dispose. The cost of the fog (Fog Elixir?) is negligible. CONTACT www.dri-sump.com

Advantages

No water or any other regulated material is used for testing…no disposal expenses

Meets or exceeds 0.10gph requirements for leak detection (3rd Party Certification available)

Method meets all requirements of the federal and state regulations for complete testing of the sides, bottom and all penetration points

Does not require the additional testing of the sensor for the hydrostatic test

Does not require test boots to be made tight in most cases

The test equipment is very compact and can be easily purchased and training is simple

Can be used to test any spill bucket or containment sump in a minute or less

Test method has been in use for years as an industry standard in other industries requiring zero tolerance for leaks.

Repairs to the sumps can be made before or after a test since the test is only one minute.

Containment sumps can be retested in minutes with the permanent installation of the VSTs. One minute test per VST

No damage or fatigue to the sump from liquid placement or displacement since no liquid is used

Vapor fog is safe for the environment and the integrity of the sump is not compromised

Disadvantages

Initial cost of the Dri-sump? test equipment

Certification of the test equipment and tester must be conducted every two years (conducted online after initial training)

Consumables for testing must be purchased (Fog Elixir?, VST) (penny’s per test for the Fog Elixir and VSTs are initial install expense in most cases

There may be an installation fee to permanently install VSTs

Additional equipment is needed to bore holes through concrete surfaces for VST installation

Subsurface conditions may not be known when installing VSTs. Safety is important

Drilling holes in concrete is loud and dusty

 

 

Dri-sump? Containment Tightness Testing has patents pending in the USA and foreign countries and has also met all requirements under Standard Test Procedures for Evaluating Leak Detection Methods: Nonvolumetric Tank Tightness Testing Methods, EPA/530/UST-90/005. It has an EPA 3rd Party evaluation and certification from Ken Wilcox Associates and meets all requirements for both federal and state regulations. 

For further information on purchasing Dri-sump equipment and becoming a certified tester please contact [email protected]  Licenses are available to sump manufacturers.