NJDEP Jurisdiction Over UST Collateral Components

When people think about underground storage tanks (USTs), they often picture a buried steel vessel holding gasoline or diesel fuel. But those who work in the field know a UST is much more than that, and the government knows it too. Under New Jersey law, the reach of the New Jersey Department of Environmental Protection (NJDEP) extends beyond just the tank itself. Pipes, fittings, containment devices, and other buried components — collectively referred to as collateral components — are part of a regulated UST system when specific criteria are met. Understanding exactly what is covered matters for registration, leak detection, closure, and remediation obligations. See our discussion below, and call Herbert Lutz & Company for installation and removal, compliance testing, site remediation, or other necessary UST services in New Jersey.

How New Jersey Defines a UST System

NJDEP’s regulatory definition of an underground storage tank system makes it clear that systems are more than just tanks. According to the New Jersey Administrative Code, an “underground storage tank” or UST means:

any one or combination of tanks, including appurtenant pipes, lines, fixtures, and other related equipment, used to contain an accumulation of hazardous substances, the volume of which — including the volume of appurtenant pipes, lines, fixtures and other related equipment — is 10% or more beneath the surface of the ground.

This means NJDEP considers the entire system, not just the vessel, when determining whether the UST rules apply. In regulatory terms, this is sometimes called an appurtenant or collateral component.

The 10% threshold is critical: if at least 10% of the total combined volume of the storage tank plus all connected underground components — including underground piping, fittings, and other submerged elements — is beneath the ground, the entire system is treated as a regulated UST. This approach mirrors the federal definition in 40 CFR Part 280.

What Constitutes a “Component” of a UST System?

Under NJDEP’s definition, the following elements are included as part of a UST system when determining regulatory applicability:

• Underground Piping and Lines: Any pipe or line that lies beneath the surface and carries regulated substances.
• Fixtures and Fittings: Structural parts such as valves, connectors, and transition points directly attached to the tank/piping system.
• Ancillary Equipment: This can include containment sumps, dispenser sumps, leak detection devices, and other hardware integral to system operation.
• Secondary Containment: Devices or systems, such as under-dispenser containment or jacketing around piping, designed to contain a potential leak until it can be detected and removed.

Importantly, these collateral components are not treated as optional add-ons; when they exist below ground and are part of a system used to contain regulated substances, they contribute to the volume calculation and regulatory status.

Why the 10% Underground Volume Rule Matters

The 10% rule is a defining line between regulated and unregulated systems. It serves two key regulatory purposes:

1. Determining Applicability: It establishes whether a given storage system, including buried piping and components, falls under NJDEP’s UST regulatory framework.
2. Inclusion of Piping and Ancillary Components: Because the rule explicitly includes connected underground components in the total volume calculation, systems with extensive buried piping or tank-to-tank connections can be regulated even if the actual tank capacity is relatively small.

This approach avoids narrow interpretations that would exclude significant parts of a leak pathway from oversight. For example, a configuration with relatively small tanks but long underground piping might still meet the regulatory criteria if the total buried volume exceeds 10% of the system’s capacity.

Examples of Collateral Components Covered by NJDEP

In practice, the following are commonly considered collateral components when assessing NJDEP jurisdiction:

• Product Piping: All buried lines from the storage tank to dispensers or equipment.
• Containment Sumps & Dispenser Sumps: Liquid-tight structures capturing leaks from piping or dispensers.
• Under-Dispenser Containment (UDC): Designed to prevent leaks from reaching soil/groundwater.
• Secondary Contained Piping: Piping with additional containment layers that enclose the line.
• Leak Detection and Monitoring Equipment: Devices installed below grade to monitor releases or secondary containment integrity.

Note that aboveground piping is generally not counted in the underground volume calculation for regulatory applicability unless it transitions below grade.

What Is Not Covered

The regulations also specify certain exclusions. For example, some tanks situated in basements or other underground rooms that remain visible and accessible, meaning all sides and the top/bottom of the tank can be viewed, do not fall under UST jurisdiction even if they meet depth criteria at the surface.

In addition, specific types of systems such as certain wastewater tanks or electrical equipment beneath ground may be excluded under separate provisions. These exceptions are tied to the nature of the stored material and the regulatory program covering that system.

Practical Implications for Owners and Operators

Understanding collateral components is essential for compliance with NJDEP’s UST program:

• Registration & Permit Requirements: A UST system includes all components considered part of the regulated system, so owners must register appropriately, reflecting the tank plus piping and related equipment.
• Release Detection & Monitoring: Collateral components are subject to technical requirements such as leak detection, corrosion protection, and secondary containment specific to piping and sumps.
• Closure & Remediation: When a system is closed or removed, the entire system — including piping and containment components — must be evaluated for potential releases and remediated appropriately.
• Site Assessments: Environmental assessments (like Phase I/II environmental site assessments) must consider buried collateral components when evaluating potential sources of contamination.

Why This Matters to You

Overlooking collateral components can lead to regulatory gaps. Misclassifying a system as “just a tank” might leave underground piping or containment systems unregulated on paper, even though they pose the same contamination risks in reality.

When planning tank installations, upgrades, monitoring, or closures, it’s important to work with contractors who understand NJDEP’s inclusive definition of UST systems. Proper identification of collateral components avoids surprises during compliance inspections or site transfers and ensures that all parts of a system are managed according to regulatory expectations. In New Jersey and Florida, contact Herbert Lutz & Company/Lutz Petroleum Equipment Installation for expert advice and assistance.