Spill Protection

Overfill Protection

Existing tanks must use ONE of the following:

• Automatic shutoff devices
• Overfill alarms
• Ball float valves

Corrosion Protection

Existing tanks must match ONE of the following:

• Steel tank has corrosion-resistant coating AND cathodic protection (such as an sti-P37 tank)
• Tank made of noncorrodible material (such as fiberglass)
• Steel tank clad with noncorrodible material (such as an ACT-1007 tank) or tank enclosed in noncorrodible material
• Uncoated steel tank has cathodic protection system
• Uncoated steel tank has interior lined with noncorrodible material
• Uncoated steel tank has cathodic protection AND interior lined with noncorrodible material

Existing piping must match ONE of the following:

• Uncoated steel piping has cathodic protection
• Steel piping has a corrosion-resistant coating AND cathodic protection
• Piping made of (or enclosed in) noncorrodible material (such as fiberglass)

Many releases at UST sites come from spills. Spills often occur at the fill pipe when the delivery truck's hose is disconnected. Although these spills are usually small, repeated small releases can cause big environmental problems.

Human error causes most spills. These mistakes can be avoided by following standard tank filling practices. For example, you must make sure there is room in the UST for the delivery, and the delivery driver must watch the delivery at all times. If you and the delivery driver follow standard practices, nearly all spills can be prevented. For this reason, state and federal UST regulations require that you follow standard filling practices now.

In addition, USTs must have catchment basins to contain spills. New USTs must have catchment basins when they are installed.  You and your fuel deliverer should see "Keeping It Clean" a video that shows how deliveries can be made safely with no spills.  If an UST never receives more than 25 gallons at a time, the UST does not have to meet the spill protection requirements. for example many small used oil tanks fall in this category.

To protect against spills, the basin should be large enough to contain what may spill when the delivery hose is uncoupled from the fill pipe. Basins range in size from those capable of holding only a few gallons to those that are much larger the catchment basin, the more spill protection it provides.

You need a way to remove liquid from catchment basins. Manufacturers equip catchment basins with either pumps or drains to remove liquid. The illustration on the previous page shows a catchment basin with a pump; the illustration below shows a catchment basin with a drain.  Your equipment supplier can help you choose the size and type of catchment basin that meets your needs.

You should try to keep water out of catchment basins. Some catchment basins can collect enough water and sediment, along with spilled product, to make draining this mixture into the tank unwise. If this happens, you may pump out the catchment basin and dispose of the liquid properly. If the liquid contains fuel or chemicals, it could be considered a hazardous waste. Contact the Department of Environment and Natural Resources' Solid Waste Program for information on testing and handling requirements.  Having the surrounding surface slope away from the top of catchment basins helps keep water out of them.

Overfills usually release much larger volumes than spills. When a tank is overfilled, large volumes can be released at the fill pipe and through loose fittings on the top of the tank or a loose vent pipe. The tightness of these fittings normally would not be a problem if the tank were not filled beyond its capacity.

You can solve overfill problems by:

• Making sure there is enough room in the tank for the delivery BEFORE the delivery is made;
• Watching the entire delivery to prevent overfilling or spilling; and
• Using equipment that protects against overfills.

State and federal rules require that existing USTs must have overfill protection devices by December 1998.

New USTs must have overfill protection devices when they are installed. The three main types of overfill protection devices (automatic shutoff devices, overfill alarms, and ball float valves) are described below and on the next page. NOTE: If you have "pumped delivery" where fuel is delivered under pressure, you must make sure your overfill protection device works compatibly with pumped deliveries. Also, remember that overfill protection devices are effective only when combined with careful filling practices.

Overfill alarms use probes installed in the tank (see illustration on the right) to activate an alarm when the tank is either 90 percent full or within 1 minute of being overfilled. Either way, the alarm should provide enough time for the driver to close the truck's shutoff valve before an overfill happens. Alarms must be located where the driver can see or hear them easily. (Overfill alarms are often a part of automatic tank gauging systems.)

Overfill alarms work only if they alert the driver at the right time and the driver responds quickly. Remember to put the alarm on an electrical circuit that is active all the time so that the alarm will always work. Many deliveries are made at night when the facility is closed. You don't want to turn off your alarm when you turn off the office lights.

Ball float valves (see illustration on the right) are placed at the bottom of the vent line several inches below the top of the UST. The ball floats on the product and rises with product level during delivery until it restricts vapor flowing out the vent line before the tank is full. If all tank fittings are tight, the ball float valve can create enough back pressure to restrict product flow into the tank which can notify the driver to close the truck's shutoff valve. However, if the UST has loose fittings, sufficient back pressure may not develop and will result in an overfill. Note: Manufacturers do not recommend using ball float valves with suction piping, pressurized delivery, or coaxial Stage I vapor recovery.

• Tank and piping completely made of noncorrodible material, such as fiberglass. Corrosion protection is also provided if tank and piping are completely isolated from contact with the surrounding soil by being enclosed in noncorrodible material (sometimes called "jacketed" with noncorrodible material).
  
  
• Tank and piping made of steel having a corrosion-resistant coating AND having cathodic protection (such as an sti-P37 tank with appropriate piping). A corrosion-resistant coating electrically isolates the coated metal from the surrounding environment to help protect against corrosion. Asphaltic coating does not qualify as a corrosion-resistant coating. Methods of cathodic protection are briefly explained on page 11.
  
  
• Tank made of steel clad with a thick layer of noncorrodible material (such as an ACT-1007 tank). This option does not apply to piping. Galvanized steel is not a noncorrodible material.

It is not practical to add coatings or claddings to existing steel USTs that have no corrosion protection. Instead, you must choose one of the following three methods to add corrosion protection to existing steel tanks:

• Add cathodic protection or
• Add interior lining to tank or
• Combine cathodic protection and interior lining.

1. Add cathodic protection. If you are adding only cathodic protection, you must do the following: (Only tanks proven to be structurally sound can have cathodic protection added to them.)

Second, install cathodic protection. 

Regulations require a qualified cathodic protection expert to design, supervise installation, and inspect cathodic protection systems installed at the UST site. The system must be tested by a qualified cathodic protection tester within 6 months of installation and at least every 3 years thereafter. You will need to keep the results of the last two tests to prove that the cathodic protection is working. In addition, you must inspect an impressed current system every 60 days to verify that the system is operating. Keep results of your last three inspections to prove that the impressed current system is operating properly.  Using Cathodic protection requires periodic tests and inspections, as well as consistent recordkeeping.

2. Add interior lining to the tank. The interior of a tank can be lined with a thick layer of noncorrodible material. Tanks using only an interior lining for corrosion protection must pass an internal reinspection in 10 years and every 5 years after that to make sure that the lining is sound. Keep records of the inspection results.

3. Combine cathodic protection and interior lining. You can add both cathodic protection and interior lining. The advantages for you of this combined method are simple: your USTs receive more cathodic protection; and you are not required to have the interior lining periodically inspected (which saves you the cost of these inspections). You will still need to have the cathodic protection system periodically tested and inspected and to keep records.

And what about piping? Existing steel piping must have cathodic protection. Note that cathodic protection needs to be tested and inspected periodically and records kept. Piping entirely made of (or enclosed in) noncorrodible material, such as fiberglass, does not need cathodic protection.

An impressed current system uses a rectifier to convert alternating current to direct current (see illustration below). This current is sent through an insulated wire to the "anodes," which are special metal bars buried in the soil near the UST. The current then flows through the soil to the UST system, and returns to the rectifier through an insulated wire attached to the UST. The UST system is protected because the current going to the UST system overcomes the corrosion-causing current normally flowing away from it.

• Notify the Department of Environment and Natural Resources (DENR) at least 30 days before you take an UST out of service for closure or replacement.
  
  
• Determine if releases from your UST have contaminated the surrounding environment. You can use the results of monthly vapor or groundwater monitoring to show that your site is not contaminated. Otherwise you will need to do a site assessment. If you find contamination, you will have to take corrective action. Contact DENR if you have questions regarding corrective action.
  
  
• Have the tank emptied of liquids, dangerous vapor levels, and accumulated sludge. These potentially very hazardous actions need to be carried out by trained personnel who carefully follow standard safety practices. After the tank has been properly emptied, you can have it removed. If you want to leave the UST in the ground, you must fill it with a harmless and chemically inactive solid.
  
  ( Warning: People are killed or injured every year while closing or removing tanks. Use safe removal practices. Only qualified contractors should close or remove USTs.)

Several hundred substances are designated as "hazardous" in Section 101(14) of the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, better known as CERCLA. The UST regulations apply to tanks that store the same hazardous substances identified by CERCLA, except for those listed as hazardous wastes. Information on CERCLA hazardous substances is available through EPA's RCRA/Superfund Hotline at 800 424-9346 or South Dakota's Department of Environment and Natural Resources Solid Waste Program at (605) 773-3153.

If your hazardous substance UST was installed before November 30, 1987, you have until December 22, 1998 to add spill, overfill, and corrosion protection. Otherwise, you must properly close the UST. By this same date, hazardous substance USTs must also have leak detection systems that include secondary containment and interstitial monitoring. The leak detection system must be able to detect a leak in the interstitial space within 30 days of occurrence.

Secondary containment is created by placing a barrier inside or outside the tank and piping so that any leaks are contained within the space between the barrier and the tank and piping. This containment space is called the "interstitial space" and must be monitored for leaks. Methods that create an interstitial space for existing systems are currently limited in number and not available everywhere.

• API (American Petroleum Institute)
  1220 L Street, N.W.
  Washington, DC 20005
  202 682-8000
  
• ASTM (American Society for Testing and Materials)
  1916 Race Street
  Philadelphia, PA 19103
  215 299-5585
  
• Fiberglass Petroleum Tank and Pipe Institute
  9801 Westheimer, Suite 606
  Houston, TX 77042-3951
  713 465-3310
  
• NACE International (formerly the National Association of Corrosion Engineers)
  Box 218340
  Houston, TX 77218-8340
  713 492-0535
  
• National Fire Protection Association
  1 Batterymarch Park
  Box 9109
  Quincy, MA 02269-9101
  617 770-3000
  
• NLPA (National Leak Prevention Association)
  Box 1643
  Boise, ID 83701
  208 389-2074
  
• PEI (Petroleum Equipment Institute)
  Box 2380
  Tulsa, OK 74101-2380
  918 494-9696
  
• STI (Steel Tank Institute)
  570 Oakwood Road Lake
  Zurich, IL 60047708 438-8265

Assessing Tank Integrity and Interior Lining of Tank

• API Recommended Practice 1631 (1992), "Interior Lining of Underground Storage Tanks"
• NLPA Standard 631 (1991), "Entry, Cleaning, Interior Inspection, Repair, and Lining of Underground Storage Tanks"
• [An ASTM consensus code may be published to standardize alternatives to internal inspections that assess tank integrity.]

Cathodic Protection

• API Recommended Practice 1632 (1987), "Cathodic Protection of Underground Petroleum Storage Tanks and Piping Systems"
• NACE RP-0169-92 (1992), "Recommended Practice: Control of Corrosion on External Underground or Submerged Metallic Piping Systems"
• NACE RP-0285-85 (1985), "Recommended Practice: Control of External Corrosion on Metallic Buried, Partially Buried, or Submerged Liquid Storage Systems"
• STI R892-91 (1991), "Recommended Practice for Corrosion Protection of Underground Piping Networks Associated with Liquid Storage and Dispensing Systems"

Closing USTs

• API Recommended Practice 1604 (1987), "Removal and Disposal of Used Underground Petroleum Storage Tanks"

General

• API Recommended Practice 1615 (1987), "Installation of Underground Petroleum Storage Systems"
• PEI RP100-94 (1994), "Recommended Practice for Installation of Underground Liquid Storage Systems"

Leak Detection Requirements

• "Straight Talk On Tanks: A Summary of Leak Detection Methods for Petroleum Underground Storage Tanks." To order this free publication, call EPA's toll-free RCRA/Superfund Hotline at 800 424-9346 and ask for EPA 530/UST-90/012.

Installing New USTs and General Information

• "Musts for USTs: A Summary of the Regulations for Underground Storage Tank Systems." Order from Superintendent of Documents, Box 371954, Pittsburgh, PA 15250-7954; order #055-000-00294-1 ($2.50 a copy).

Taking Corrective Action

• "Oh No! Petroleum Leaks and Spills: What Do You Do?" To order this free publication, call EPA's toll-free RCRA/Superfund Hotline at 800 424-9346 and ask for EPA 530/UST-88/004.

Tank Filling

• "Keeping It Clean: Making Safe and Spill-Free Motor Fuel Deliveries." For ordering information call EPA's toll-free RCRA/Superfund Hotline at 800 424-9346 (video costs about $60).

Closure

• "Tank Closure Without Tears" and "What Do We Have Here?" Videos and companion booklets available ($20 to $45) from New England Interstate Water Pollution Control Commission, ATTN: VIDEOS, 2 Fort Road, South Portland, ME 04106.

You should be in compliance with the "upgrade" requirements if you can check off the major items below for each of your existing UST systems by December 1998:

• Spill protection provided by a catchment basin
• Overfill protection provided by an automatic shutoff device, overfill alarm, or ball float valve
  
  
• Corrosion protection for the tank provided by one of the following:

• Steel tank has corrosion-resistant coating AND cathodic protection
• Tank made of noncorrodible material (such as fiberglass)
• Steel tank clad with (or enclosed in) noncorrodible material
• Uncoated steel tank has cathodic protection system
• Uncoated steel tank has interior lined with noncorrodible material
• Uncoated steel tank has cathodic protection AND interior lined with noncorrodible material steel tank
  
  

• Corrosion protection for piping provided by one of the following:
  
  
  • Uncoated steel piping has cathodic protection
  • Steel piping has a corrosion-resistant coating AND cathodic protection
  • Piping made of (or enclosed in) noncorrodible material