Materials Used in Secondary Containment: Choosing the Best Option

Secondary containment is a vital aspect of managing hazardous materials, ensuring that they do not pose a threat to the environment, public health, or safety. As industries and businesses handle chemicals, fuels, and other potentially dangerous substances, the risk of spills or leaks is ever-present. Secondary containment systems provide an extra layer of protection, preventing the spread of hazardous substances and minimizing their environmental impact. This article explores the significance of secondary containment, its role in spill prevention, its components, and how businesses can design and implement effective systems to comply with regulatory standards.

What is Secondary Containment?

Secondary containment refers to a system or structure that is designed to capture and contain hazardous substances in the event of a primary containment failure, such as a tank rupture, pipe leak, or other accidents. The goal of secondary containment is to prevent dangerous chemicals, fuels, or other substances from spilling into the surrounding environment and contaminating the land, water, or air.

In simple terms, secondary containment acts as a safety net that catches and holds the material if the primary containment system fails. This system is commonly used in industries such as chemical manufacturing, oil and gas, agriculture, and waste management. Its purpose is to minimize the environmental and health risks associated with hazardous materials and ensure compliance with regulatory requirements.

The Importance of Secondary Containment

1. Environmental Protection: The most significant role of secondary containment is protecting the environment from spills and leaks. Hazardous substances such as petroleum, chemicals, and pesticides can contaminate soil, groundwater, and surface water, causing long-term ecological damage. Secondary containment prevents such disasters by providing a secondary barrier that contains the spill before it can spread.
2. Regulatory Compliance: Regulatory bodies like the Environmental Protection Agency (EPA) in the United States, the European Union, and other national or regional authorities have set strict regulations for the storage and handling of hazardous materials. These regulations often require businesses to implement secondary containment systems to mitigate the risk of spills and leaks. Failure to comply with these regulations can result in fines, penalties, or legal action.
3. Safety of Employees and the Public: Hazardous materials pose a direct risk to human health, both for workers handling the substances and for the surrounding community. Secondary containment systems help to safeguard human life by minimizing the risk of exposure to harmful chemicals, reducing the likelihood of accidents, and enabling quick spill response.
4. Cost Savings: Although implementing a secondary containment system involves an upfront investment, the long-term cost savings are substantial. The cost of cleaning up a spill, dealing with environmental damage, and paying for regulatory fines can far outweigh the costs of installing an effective containment system. Secondary containment can prevent financial losses related to spills, product recalls, and lawsuits.

Types of Secondary Containment Systems

The design of secondary containment systems depends on the type of hazardous material being stored, the facility’s layout, and specific regulatory requirements. There are various types of secondary containment systems, including:

1. Containment Berms and Dikes: Berms and dikes are barriers that are placed around storage tanks or containers to prevent spills from spreading. They are typically constructed from impermeable materials such as concrete, metal, or high-density polyethylene (HDPE). These structures can be either permanent or portable, depending on the needs of the facility.
2. Curb and Gutter Systems: These systems are often used in conjunction with containment berms and provide an additional layer of protection. Curb and gutter systems channel and direct spilled liquids into a containment area, preventing them from flowing into drainage systems or contaminating larger areas.
3. Double-Walled Tanks: Double-walled tanks consist of an inner tank, which holds the hazardous material, and an outer shell, which provides secondary containment. In case of a leak or rupture of the inner tank, the outer tank contains the spilled material, preventing it from reaching the environment. Double-walled tanks are commonly used for storing fuels and chemicals.
4. Trays and Pans: Small-scale containment systems, such as trays and pans, are used under smaller containers or equipment. These systems catch any leaks or spills from the primary container, providing an easy-to-clean containment solution. They are often used in laboratories, warehouses, and small chemical storage areas.
5. Liners and Pits: Liners are placed at the bottom of a containment area to prevent leaks from penetrating the ground. These can be made from materials such as PVC, rubber, or reinforced polyethylene. Liners are often used in conjunction with containment pits, which are designed to hold large volumes of liquids.
6. Spill Pallets: Spill pallets are platforms with built-in containment features, often used for storing barrels or containers of hazardous materials. They have a raised edge to prevent spills from spreading and usually feature a grate that allows liquid to drain into a lower containment reservoir.

Design Considerations for Secondary Containment Systems

Designing an effective secondary containment system involves several key factors. These include:

1. Capacity: The containment system must be able to hold a sufficient volume of material to contain a potential spill. Typically, the secondary containment system should have a capacity equal to or greater than 110% of the volume of the largest container being stored. In some cases, regulatory authorities may require a higher capacity, depending on the potential for large-scale spills.
2. Material Selection: The materials used to construct the secondary containment system must be compatible with the substances being stored. For example, petroleum products require containment systems made from materials resistant to oil, while corrosive chemicals may require systems made from materials that are resistant to corrosion.
3. Accessibility: The system should be designed for easy inspection, maintenance, and cleaning. Regular inspections are essential to ensure that the containment system is functioning properly and that there are no signs of damage or wear.
4. Location: The secondary containment system should be located in an area that minimizes the risk of external factors, such as flooding, that could compromise its integrity. Additionally, it should be placed in an area that allows for easy access and quick response in case of an emergency.
5. Monitoring and Detection: Some secondary containment systems are equipped with monitoring and detection devices that alert facility operators to potential leaks or breaches. These systems may include sensors that detect changes in pressure, temperature, or liquid levels.

Regulatory Requirements for Secondary Containment

Secondary containment is subject to numerous regulations that vary by region and industry. Some of the key regulations that businesses need to consider include:

1. EPA Regulations (U.S.): The EPA has established regulations for secondary containment in the context of the Clean Water Act (CWA) and the Resource Conservation and Recovery Act (RCRA). These regulations mandate that facilities that store hazardous materials must implement secondary containment measures to prevent spills from contaminating water sources.
2. SPCC Plan (Spill Prevention, Control, and Countermeasure): Under the EPA’s SPCC rule, facilities that store oil and petroleum products in quantities greater than 1,320 gallons must develop and implement an SPCC plan, which includes secondary containment requirements. The SPCC plan outlines how a facility will prevent and respond to spills.
3. OSHA Standards (Occupational Safety and Health Administration): OSHA requires facilities to implement safety measures to protect workers from hazardous materials. This includes ensuring that secondary containment systems are in place and functioning properly to reduce the risk of exposure to toxic chemicals.
4. International Regulations: In addition to U.S. regulations, other countries have their own requirements for secondary containment. For example, the European Union’s REACH regulations and the Australian Work Health and Safety (WHS) codes mandate secondary containment for hazardous chemicals in certain industries.

Best Practices for Implementing Secondary Containment

1. Conduct a Risk Assessment: Before implementing secondary containment, businesses should conduct a risk assessment to determine the potential for spills and leaks. This will help identify areas of concern and guide the design of the containment system.
2. Select the Right Type of System: Based on the nature of the stored materials, businesses should choose the most appropriate secondary containment system. Considerations include material compatibility, storage volume, and the environmental conditions of the facility.
3. Regular Inspections and Maintenance: Secondary containment systems should be inspected regularly for signs of damage or wear. Any issues, such as cracks, leaks, or corrosion, should be addressed immediately to maintain the integrity of the system.
4. Employee Training: Employees should be trained in the proper use and maintenance of secondary containment systems. They should also be aware of emergency response procedures in case of a spill.
5. Document Compliance: Businesses should maintain records of their secondary containment systems, including design plans, inspection reports, and regulatory compliance documentation. This ensures that the facility meets legal requirements and can demonstrate its commitment to safety and environmental protection.

Conclusion

Secondary containment is a critical aspect of environmental and workplace safety, providing an additional layer of protection against spills and leaks of hazardous materials. By understanding its importance, selecting the right type of system, and ensuring regulatory compliance, businesses can effectively prevent environmental damage, reduce risks to human health, and avoid costly fines and legal repercussions. Implementing secondary containment systems not only helps protect the environment but also contributes to the long-term sustainability and success of a business.