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Bulk Petroleum Product Storage Terminals

Storage terminals range in size from very small product storage facilities with aboveground tanks smaller than 1,000 gallons to large interconnected facilities with individual tank capacities of several million gallons. Materials stored at these terminals can be both raw and/or finished products including crude oil, refined petroleum (fuel) and petrochemicals. The primary hazards at these sites are fire, tank failure, release of hazardous vapors and spills resulting in environmental pollution, property damage and loss of products. Highly flammable petroleum products, such as gasoline, present additional fire and explosion hazards that may result in injury to employees and surrounding neighbors. All of these hazards can be reduced with an effective risk control program that includes best management practices addressing hazard evaluation, engineering controls, employee training, inspection and preventive maintenance, and pre-emergency planning.

Hazard Evaluation

A visual survey of the terminal should be conducted to inspect the condition of the tanks, equipment and containment, and assess the effectiveness of operating procedures and security. The purpose of the survey is to assess the adequacy of the current facility design, operation and practices; uncover any obvious deficiencies; determine the potential amount of risk posed by the terminal; and, ultimately, determine corrective action priorities. The amount of risk posed by a storage terminal depends upon several of the following factors:

  • Size and location
  • Security measures
  • Age and condition
  • Construction/engineering features
  • Operations and products stored
  • Maintenance/inspection procedures
  • Risk reduction measures (i.e. training, fire suppression)

Recent studies by the American Petroleum Institute (API) indicate that the causes of petroleum-related releases generally fall into four categories:

  • Physical damage to tanks, valves pumps and ancillary equipment
  • Tank and equipment leaks from mechanical failure, corrosion, and faulty valves and seals
  • Improper product handling and employee or contractor negligence
  • Poor housekeeping practices

Vandalism and weather-related events are cited as the two most common factors associated with release frequency and severity, respectively.

Engineering Controls

Appropriate equipment and instrumentation should be engineered into facility designs that will result in inherently safe operations. Effective engineering controls should:

  • Protect piping, tanks and pressure vessels by providing adequate pressure relieving devices
  • Provide intermediate alarms to allow the operator time to take corrective action
  • Provide automatic shutdown for selected equipment wherever possible without endangering other terminal operations
  • Provide redundant instrumentation for all critical controls

The following engineering controls can minimize the amount and hazards of materials released by equipment failure:

  • Shutdown systems, block valves, venting systems, and purging or flooding of equipment with a nonhazardous fluid (i.e. water, foam). Combustible vapor detectors should be considered as a means of detecting accidental releases of gas or liquefied gases
  • Design and equipment specifications that consider all possible operating conditions, both normal and abnormal. Evaluate the suitability of the equipment and piping to handle the materials and to withstand external environmental influences (i.e. wind, snow loading, corrosion, earthquakes)
  • High-level detection devices coupled to alarms with automatic shutoffs or flow diverters should be installed on tanks independent of gauging equipment

Release Prevention

The key components of a release prevention program are engineering, inspection, testing and maintenance programs to minimize the potential for equipment leaks, and operator training to prevent and respond to spills. Adequate facility security is also extremely important due to the potential for vandalism, sabotage or terrorism.

Because of the location and unique layout of pipelines and pump stations serving storage terminals, management personnel are usually at a central location providing supervision to the pipeline network. Adequate loss control measures for pipelines should include the following:

  • Engineering design and construction in accordance with National Fire Protection Association, American Petroleum Institute, American Society of Mechanical Engineers, or National Association of Corrosion Engineers standards. Design should also include accessibility for maintenance
  • Proper support and protection from traffic and physical damage
  • Pumps listed for the type of service and provided with containment to catch product losses from bearings, packings and seals
  • Preventive maintenance and inspection programs, including metals inspection, vibration analysis and non-destructive testing programs
  • Adherence to U.S. Coast Guard and U.S. Environmental Protection Agency integrity testing standards

Transfer operations such as ship/barge unloading and truck loading represent great potential for sudden release of product to the environment. Unless a catastrophe occurs, transfer spills are generally small relative to the amount of liquid being handled. However, they can occur frequently enough to constitute a major source of product loss and cumulative damage to the environment.

There are many potential causes of transfer spills, and accidents cannot be completely eliminated; however, written operating procedures can reduce spill frequency and severity when combined with other best management practices.

Written procedures should ensure the following:

  • Tank truck engines are shut off and wheels are chocked to prevent movement during transfer.
  • Tanks and trucks should be properly grounded when transferring flammable materials to prevent explosions. Avoid flow rates and splash filling that may generate static charges.
  • The tank to receive product must be gauged and the amount of free volume ascertained to make sure that there is enough capacity. The tank level should be gauged frequently during product delivery.
  • When more than one tank is in the storage area, fill ports must be verified so that the proper tank is receiving the product.
  • Hoses and fittings must be checked for condition, leaks and improper connections. Catch basins or drip pans should be placed at uncoupling points to capture spills.
  • Require an attendant to be present during transfer operations to oversee equipment and communicate problems via radio or other means.

Employee Training

The OSHA Hazard Communication Standard requires employers to develop, implement and maintain a training program covering safe handling of chemicals used or stored on site. Periodic re-education and training of the operators and contractors should be conducted. Include testing to assure proper performance of all assigned duties. Reinforce adherence to written operating procedures. Educate all operators in the hazards of the facility equipment and functions of the safety control equipment. Forbid operations when any of the safety equipment is out of order. Train operators in manual emergency shutdown procedures and spill response procedures.

Inspection And Preventive Maintenance

Tanks and equipment should be inspected regularly to assess the condition and operation of equipment and structures, the rate of deterioration and its cause. Inspections should involve:

  • external examination of the tanks, equipment, containment and surroundings.
  • internal inspection of the tanks and tank bottoms.
  • nondestructive tank testing to assess structural integrity and likelihood of future releases.
  • establishment of a detailed record keeping system, including life extension forecasts or projections.

The level of detail and frequency of inspections and testing should depend on the severity of the threat to life and property posed by an undetected leak or sudden release from tanks and/or equipment and any jurisdictional requirements. Terminals which store highly hazardous products and facilities utilizing older tanks and piping should be subject to more rigorous inspection/testing programs. Industry standards, such as API 653 Tank Inspection, Repair, Alteration and Reconstruction, should be referenced for recommended integrity testing protocols and frequencies.

Visual inspections should be supplemented periodically with nondestructive testing of tanks and key components. Nondestructive testing is used to assess the integrity of the tank and equipment, and likelihood of future releases. Testing can include measurement of the rate of erosion and corrosion wear, and assessment of cracking, pitting and material compatibility. Types of nondestructive testing include, among others, ultrasonic, x-ray and hydrostatic.

Any equipment identified as deficient during an inspection/testing should be monitored and repaired or replaced as necessary. Regular, preventive maintenance programs should be established to limit expected releases. Maintenance programs should address the following:

  • Equipment with predictable or expected lifetimes should be replaced in accordance with manufacturers’ recommendations or the project life.
  • Pumps and other mechanical equipment should be regularly lubricated. Hoses should be checked for abrasion or UV degradation.
  • Corrosion rates of metal parts should be established and the parts replaced when they reach a predetermined level.
  • Oil/water separators should be regularly maintained to ensure proper treatment of contaminated stormwater.

Spill and Fire Pre-Emergency Planning

Pre-emergency planning includes development of appropriate written emergency response plans, maintaining appropriate response equipment, and training personnel or retaining professional assistance. The following steps are essential:

  • Establish an emergency response and evacuation plan to address fires, spills and other emergencies. Environmental, occupational safety and fire safety regulatory agencies should be contacted to determine requirements of various mandated emergency plans and reporting requirements.
  • Emergency plans should include clear procedures for hazardous material spill response and cleanup. All spills, regardless of the size, should be immediately addressed to prevent ongoing impacts to stormwater, surface water and groundwater.
  • Designate employees responsible for emergency response procedures. Train employees on their responsibilities and conduct emergency response drills at least annually.
  • Stage spill response equipment, absorbent materials, fire extinguishers and personal protective equipment near hazardous material storage areas and product loading/unloading areas. Ensure operators are trained on equipment use and storage locations.

The storage terminal should be designed in accordance with all applicable fire codes and regulations. This includes maintaining minimum distances between tanks, buildings, key equipment and property lines; installing tanks that are of approved design and construction; and ensuring all electrical equipment is approved and listed for hazardous service.

Routine inspections, tests and maintenance of sprinkler systems, fire alarms, fire extinguishers and other emergency response equipment should be conducted. Terminals should install some type of fixed or semi-fixed foam or water system. Foam protection should be provided for areas where flammable or combustible liquids are stored. Deluge systems should be provided for product loading/unloading areas. Ensure that the local fire department is aware of emergency plans and the locations of hazardous material storage areas on site.

XL Environmental • Risk Control Division • 520 Eagleview Boulevard, PO Box 636, Exton, PA 19341 • Phone: 800-327-1414 • Fax: 610-458-7285 • xlenvironmental.com

XL Environmental is a division of XL Specialty Insurance Company.

 
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