Aboveground storage tank on the subject property

The subject property has an aboveground storage tank (AST) holding petroleum or a chemical, with or without secondary containment. The tank alone does not settle whether there is a recognized environmental condition (REC). That depends on four things: what the tank holds, whether there is evidence of a release, whether its condition poses a material threat of release, and what its history shows.

What the answer turns on

A REC takes one of three forms. Hazardous substances or petroleum products are present at the subject property because of a release; likely present because of a release or a likely one; or present where conditions make a future release a material threat (E1527-21, 3.2.73).

What the tank holds. Only hazardous substances and petroleum products count, and fuels such as gasoline, diesel and fuel oil are petroleum products (E1527-21, 3.2.61, 3.2.73). The description of a tank should give its construction, contents, capacity and age (E1527-21, 9.4.12).
Evidence of a release. The standard's appendixes are nonmandatory; the one on the REC definition gives stained soil under an aboveground petroleum tank as an observation that could be direct evidence of a release (E1527-21, X4.1). The definition speaks of a release to the environment (E1527-21, 3.2.73); establish where spilled product went. A release that is found is weighed against the de minimis definition (E1527-21, 3.2.20): see staining on pavement or soil.
A material threat. Three things make one: the threat is obvious, a release is likely to follow, and the environmental professional judges that the release would likely affect public health or the environment (E1527-21, 3.2.52, 3.2.55). The definition's own example is a damaged AST system holding a hazardous substance, where the damage counts if judged serious enough that it could help bring about failure of the tank and loss of its contents (E1527-21, 3.2.52). That appendix illustrates with a damaged diesel tank outdoors on gravel, with no roof, bollards or containment structure and no staining beneath; the result rests on the assessor's opinion of its obvious condition (E1527-21, X4.3). Nothing in the standard makes secondary containment, or the lack of it, decide the question alone. Whether the tank meets tank rules is regulatory compliance, a non-scope consideration (E1527-21, 13.1.5.14).
The tank's history. The professional considers what releases past uses, past storage among them, could have led to (E1527-21, 8.3.1, 9.4.2). Establish how long tanks have stood on the subject property, whether earlier tanks were removed, and whether a release was reported. One addressed to an agency's satisfaction raises the historical and controlled REC definitions (E1527-21, 3.2.17, 3.2.39).

The records that bear on it

Site visit. Storage tanks, aboveground ones included, are features the site visit must look for and the report must describe, found or not (E1527-21, 9.4, 9.4.12). So are odors, drains and sumps, stained soil or pavement and stressed vegetation (E1527-21, 9.4.13, 9.4.21, 9.4.23, 9.4.24).
Tank registrations. Registered tank lists are a standard source, with a required minimum search of the subject property and adjoining properties (registered storage tanks; E1527-21, 8.2.2, Table 2). Texas names ASTs of 1,100 gallons or less among its exemptions (Texas). Florida's agency says it routinely discovers unregistered aboveground systems in service (Florida). Idaho's agency says its tank program does not regulate ASTs (Idaho).
Release records. The required minimum search covers the subject property for federal release reports and half a mile for leaking tank lists (E1527-21, Table 2). For a listed subject property the agency file should be reviewed, or the report explains why not (E1527-21, 8.2.3.1).
Documents. Before the site visit the owner, key site manager and user are asked for tank registrations, spill prevention plans and cleanup reports (E1527-21, 10.8.1).

What the federal rule says

The rule's objective names threatened releases beside releases:

The standards and practices set forth in this part for All Appropriate Inquiries are intended to result in the identification of conditions indicative of releases and threatened releases of hazardous substances on, at, in, or to the subject property.

40 CFR 312.20(e)

For a party seeking the liability protections that objective stops at hazardous substances; the standard includes petroleum products (E1527-21, 1.1.2).

How it is written up

The tank is a finding when the professional judges it may indicate hazardous substances or petroleum products present or likely present at the subject property, and a finding need not fall into any class (E1527-21, 12.5).

Where the professional concludes a release, or a likely one, has left product present or likely present at the subject property, the opinion gives the evidence. Unless judged a de minimis condition or a historical REC, the REC is listed in the Conclusions, and the professional should give an opinion on additional investigation (E1527-21, 3.2.20, 3.2.39, 12.6, 12.7, 12.8).

Where the professional concludes there is no release but a material threat of one, the opinion names the obvious condition and why a release with likely impact is expected, and the REC is listed (E1527-21, 3.2.52, 12.6, 12.7).

Where the professional concludes neither, an opinion on a finding still gives its rationale (E1527-21, 12.6).

Observation of a tank in a locked enclosure, or an interview with the key site manager, may be what cannot be had. Required information that good faith efforts could not obtain is a data gap, significant if it affects the ability to identify a REC: named in the Findings with the sources consulted, discussed in the Opinions and listed in the Conclusions (E1527-21, 3.2.19, 3.2.78, 12.5.1, 12.6.2, 12.7).

This page is general reference for environmental professionals. It does not classify any property. ASTM E1527-21 is the standard and is not reproduced here; the judgment of the environmental professional on the facts governs.