What is a secondary containment? Definitions, solutions and requirements

Secondary containment is a critical part of environmental protection, designed to prevent spills of hazardous liquids from reaching soil, water, or other sensitive areas. From fuel storage tanks to chemical processing facilities, secondary containment ensures that if a primary container leaks, the liquid is safely captured. 

In this article, we explore what secondary containment is, its types, solutions, regulatory requirements, and how it helps protect both industries and the environment. We draw on authoritative sources such as the EPA, OSHA, WorkSafe New Zealand, and EGLE, giving you reliable guidance for prevention and compliance. This guide also highlights practical oil spill solutions and operational tools to minimize environmental damage.

What is a secondary containment?

Secondary containment refers to a backup system designed to capture leaks or spills from primary containers such as tanks, drums, or process vessels. Its main purpose is to prevent hazardous liquids from escaping into the environment, reducing risks to soil, waterways, and human health. Secondary containment can be passive (a physical barrier like a berm or sump) or active (systems with alarms, pumps, or automatic shut-offs).

Primary vs. secondary containment: what sets them apart

• Primary containment: the main vessel holding the liquid, such as a storage tank or drum. Its failure would result in a leak.
  
• Secondary containment: a backup system that captures any accidental release from the primary container. Examples include secondary containment tanks, bunded areas, or portable spill trays.
  

For instance, a chemical storage tank may sit inside a concrete berm. If the tank ruptures, the secondary containment prevents the chemical from reaching the soil or nearby watercourses. Understanding what causes oil spills helps in planning these containment measures effectively.

Why is secondary containment so important?

Secondary containment reduces environmental, legal, and financial risks by:

• Minimizing the impact of spills on soil and water.
  
• Complying with federal and state regulations (EPA SPCC, OSHA, EGLE).
  
• Protecting workers and communities from exposure to hazardous liquids.
  
• Allowing rapid response using operational tools such as oil spill kits, oil absorbent mats, and oil absorbent pads.
  
• Preventing escalation of small leaks into major environmental incidents.
  
• Helping mitigate the effects of oil spills on animals, soil, and waterways.

Comparing active and passive secondary containment for spill protection

• Passive containment relies on physical structures that require no active operation, such as berms, double-walled tanks, and containment trays.
  
• Active containment includes systems that respond to leaks automatically: pumps, sensors, alarms, or drainage control systems.
  

Both approaches can be combined for maximum protection. For example, a secondary spill containment system may include a double-walled tank (passive) plus leak sensors and an alarm (active).

Industries where secondary containment is commonly used

• Petrochemical industry: storage tanks and pipelines for oil, fuel, and lubricants, protecting against oil spills on land.
  
• Chemical processing plants: hazardous chemicals require secondary containment coatings and tanks to prevent environmental contamination.
  
• Marine operations: ports, docks, and offshore platforms rely on booms for oil spills and oil skimmers to manage oil spill effects on oceans.
  
• Manufacturing facilities: large drums of corrosive liquids are stored in secondary containment systems to avoid accidental release.
  
• Agriculture and fuel storage: fuel tanks for farming equipment benefit from secondary containment for chemicals to reduce risks in flood-prone areas.
  

Identifying where oil spills happen most frequently helps prioritize containment solutions and emergency planning.

Most common secondary containment solutions and examples

Secondary containment solutions can be portable, operational, or structural, depending on the application. Test 1 products excel in operational containment and rapid deployment for emergencies.

• Oil spill kits: pre-assembled kits including sorbent socks, oil spill mops, protective gear, and disposal bags. Ideal for immediate response.
  
• Booms for oil spills: barriers that contain spills in open water, preventing further oil spill effects on oceans.
  
• Oil absorbent mats and pads: for quick absorption of surface leaks, particularly on hard floors or near sensitive equipment.
  
• Oil skimmers: mechanical devices that remove oil from water surfaces.
  
• Oil spill absorbent materials: including reusable or disposable products that trap spilled liquids.
  
• Historical incidents such as the Odyssey oil spill and other famous oil spills highlight the importance of having rapid containment and recovery tools.
  

Operational tools such as oil spill solutions, mats, pads, and skimmers complement structural containment and make it easier to comply with secondary containment requirements while limiting the effects of oil spills on animals and ecosystems.

Secondary containment requirements and regulations

Regulatory requirements for secondary containment vary by country but share the same goal: preventing hazardous releases into the environment.

In the United States, the Environmental Protection Agency (EPA) outlines specific secondary containment requirements under 40 CFR 264.175 and 40 CFR 267.195. These rules apply to facilities storing hazardous waste or substances that pose a threat to water and soil.

Key principles include:

• The secondary system must be capable of holding 110% of the largest container’s volume or 10% of the total volume stored, whichever is greater.
  
• Materials used must be impermeable and chemically resistant to the stored substance.
  
• Regular inspection and maintenance are mandatory to ensure containment integrity.
  

The Occupational Safety and Health Administration (OSHA) also includes spill prevention and control standards under 29 CFR 1910.106, emphasizing safety in chemical handling and storage.

In other regions, such as Europe and New Zealand, local environmental agencies like the Health and Safety Executive (HSE) and WorkSafe NZ enforce similar guidelines, ensuring secondary containment systems are built, operated, and inspected to prevent contamination. Following these guidelines ensures compliance and reduces risks associated with oil spills on land, chemical leaks, and effects of oil spills in sensitive areas.

Final considerations

Effective secondary containment is essential for industrial safety, environmental protection, and regulatory compliance. Combining structural systems with operational tools like oil spill kits, oil absorbent mats, oil absorbent pads, sorbent socks, oil spill mops, oil spill absorbent materials, booms for oil spills, and oil skimmers ensures rapid response. 

Understanding facts about oil spills and what causes oil spills helps industries plan better, minimize risks, and protect ecosystems from oil spill effects on oceans, wildlife, and human populations.

FAQs

What is the OSHA standard for secondary containment?

OSHA requires employers to implement containment measures that prevent hazardous liquid spills from reaching soil or water, following 29 CFR 1910.106.

What are the pros of secondary containment?

It prevents environmental contamination, reduces cleanup costs, and ensures compliance with EPA and OSHA regulations.

Is secondary containment mandatory?

Yes, for most facilities storing oils, fuels, or hazardous chemicals. Regulatory agencies require it as part of spill prevention and control plans.

What materials are used in secondary containment?

Common materials include steel, concrete, polyethylene, and composite coatings designed to resist corrosion and chemical degradation.

Are absorbent materials considered secondary containment?

Not typically. Absorbents such as oil spill absorbent materials or pads are part of cleanup efforts, not structural containment.

What happens if a company doesn’t have proper secondary containment?

Failure to comply may result in environmental damage, heavy fines, and possible legal action from regulatory bodies.

Bibliography

U.S. Environmental Protection Agency (EPA) – 40 CFR 264.175, 267.195, Spill Prevention, Control, and Countermeasure (SPCC) Rule.

OSHA – 29 CFR 1910.106: Flammable Liquids.

WorkSafe New Zealand – Secondary Containment Systems Guidance.

Michigan Department of Environment, Great Lakes, and Energy (EGLE) – Secondary Containment Guidance.