UST Sump and Spill Bucket Testing Requirements for New Hampshire Tank Owners and Operators
Figure 1: CommTank technician installing a split repair fitting in a UST sump.
In 2015 the EPA updated federal UST regulations to require periodic testing of both new and existing containment sumps used for interstitial monitoring. Containment sumps used for reasons other than interstitial monitoring of piping do not have to meet the periodic testing requirement. Spill prevention equipment, more commonly known as spill buckets, must also be tested. The state of New Hampshire Department of Environmental Service (NHDES) set a deadline of December 22, 2017 for testing containment sumps and spill buckets and triennially thereafter.
Spill buckets are designed to contain drips and small spills that occur when the delivery hose is disconnected from the fill pipe. They are not intended nor designed for the storage of petroleum products so cleaning them during monthly walkthroughs is important. According to NHDES Env-Or 400 spill containment equipment must have a liquid capacity of 5 gallons or more and be installed to the manufacturer's requirements. Testing ensures the containment is capable of containing the fuel that spills during deliveries. Testing should demonstrate that the system performs as well as it did upon installation.
Containment sumps act as the collection point for leaks that occur in the product piping or pumps. Liquid sensors are set just above the sump floor and will activate when they encounter fuel or water. The sump must be capable of holding liquid otherwise the sensor will never be triggered. Testing ensures that the secondary containment system will function as intended and alert owners to a problem with their fuel storage tank.
Figure 2: A hydrostatic test of a 5-gallon double-wall spill bucket.
All spill buckets must pass a tightness test at installation to ensure the spill bucket is liquid-tight by using vacuum, pressure, or liquid testing. The standard for declaring a failure is .08 inch or greater loss of water within one hour (which is equal to a release/leakage rate of 0.05 gallons per hour in a typical 12-inch diameter basin). Prior to testing the drop tube is removed from the riser pipe and the drain valve is sealed. It is important to seal the drain valve because it could allow water to enter the tank and produce a test failure.
- Clean the spill bucket and check for physical damage
- Check the fill cap gasket and make sure it is in good working condition
- Measure the height of the fill pipe that is visible in the spill bucket
- Move the tape measure to the sidewall of the spill bucket and mark the height with a grease pen that is ¼ less than the measurement taken in step 3.
- Replace the fill cap and lock it in place.
- Slowly fill the spill bucket to the line marked in step 4.
- Make a note of the time to mark the start of testing.
- Reexamine the liquid level in 1 hour.
- If the level hasn’t changed or the level of change is less than 1/8 inch then the spill bucket has passed.
- If the change in water level is more than 1/8 inch then the spill bucket has failed the test and must be repaired or replaced.
NHDES suggests that a UST facility contracting with a tank testing company ask about the use of new or reused testing fluid, and clarify who will be responsible for proper disposal of the fluid when it needs to be discarded.
Figure 3: A hydrostatic test of a polyethylene transition sump
Secondary containment for USTs consists of the outer wall of double-wall tanks, the outer wall of double-wall product piping, under-dispenser containment, and submersible pump and piping sumps. To test that these sensors are working properly the State of New Hampshire requires that all containment equipment be tested no later than December 22, 2017, and triennially thereafter. Test methods can be specified by the manufacturer or conform to one of the following:
- PEI RP 1200 for tightness testing or an applicable test from the reference standards specified in the section that is specific to the component being tested
- An applicable test from the reference standards that is certified to meet the leak rate detection criteria
- A hydrostatic tightness test
- A pneumatic tightness test
Hydrostatic Tightness Testing is the most common method used. The test consists of these steps:
- Fill sump with water to a level that is within one inch of the top
- Record water level at the beginning and end of the test
- Test for a minimum of 3 hours
The test is considered passing when there is no sign of leaks or loss of liquid during the test. Testing and inspection records for spill and overfill prevention equipment and containment sumps used for interstitial monitoring of piping must be kept for three years.
The tester is required to immediately notify the NHDES and UST facility owner of a test failure. Spill buckets and containment sumps that fail must be repaired or replaced within 30 working days. The owner can notify the NHDES if there are circumstances beyond the owner’s control that prevent the repair of a containment sump within 30 days. If the spill bucket cannot be repaired within 30 days then no deliveries will be allowed until acceptable repairs are made.
Figure 4: Groundwater entered this UST sump through the rubber entry boots
Many UST owners have problems with water leaking into their spill buckets. Groundwater levels rise every spring and surround many USTs. Snowmelt clogs storm drains and causes water to form small ponds in parking lots. Heavy rains create streams along driveways and low areas where drainage is poor. Despite the elements, UST owners must keep that water from entering their tanks. The secondary containment that protects your tank, sumps, and piping from leaking into the environment must also keep water out. This is why so many tank owners are familiar with water in underground tank sumps.
Third-party tank inspectors and underground tank testers see water in sumps frequently. How the water gets in isn’t easy to determine. There are 5 ways that water can enter a tank sump.
- Sump lid isn’t watertight and is allowing water to pass into the sump from above.
- Sump sidewall is cracked or split.
- Secondary containment boot is torn or punctured.
- Electrical or pipe fitting entries are leaking.
- Gasket or seal around the riser pipe for the turbine pump is leaking.
A sump full of oily water will fail to perform as intended and won’t contain a leak from the fuel lines. Allowing the water to remain in the sump will lead to corrosion of metal pipes and fittings.
Figure 5: CommTank technician using a jackhammer to break up the top of a UST pad.
A common method for sump repair is to remove the concrete over the sump, clear the soil around the sump, and expose the top of the tank. Disconnect the piping, install a new sump over the tank, and restore the soil and concrete. Costs for this work range from $12,000 to $15,000 depending on the size of the tank and the number of manways. The UST is offline for the duration of the project resulting in a disruption of service. A temporary tank system can be set up to minimize downtime, increasing the cost of the project.
If you have a leaking UST sump it doesn’t mean that it has to be replaced. Adhesive technologies have come a long way in the past 5 years. Epoxies can now be used underwater, under pressure, and in less than ideal temperatures. Repairs can be applied to existing sumps without taking the fuel system offline. Stopping water leaks is done with fast-acting urethane foam that provides temporary blocking of active water leaks.
Figure 6: Technician applying Icon's “FastFill” filler into the encapsulation split repair fittings.
Sump cracks, holes or seam leaks can be repaired using a fast-setting, two-part structural plastic adhesive bonder. Minor repairs may be cured sufficiently for testing in 6-8 hours. The replacement of leaking existing entry fittings is done without disconnecting fuel pipes using a split repair boot. Split repair fittings can be customized to work with all brands of sump, fitting, and pipe combinations. Costs for this work range from $2,000 to $3,000 depending on the number of entry boots within a sump and style of the fittings.
The fittings are designed to last through the end-life of the sump and require no disconnections of sump entry pipes or excavation. After installation, the sump can be tested immediately. Sump repair products should meet UL971 - Standard for Nonmetallic Underground Piping for Flammable Liquids. Make sure to use a certified installer of sump leak repair products to meet conditions of the manufacturer’s product warranty.