REC, CREC, HREC or de minimis condition

A release of hazardous substances or petroleum products at the subject property is known or likely. The standard has four classes for it: a recognized environmental condition (REC), a controlled recognized environmental condition (CREC), a historical recognized environmental condition (HREC) and a de minimis condition. Which applies depends on four questions, in the order the standard's appendix takes them: presence or likely presence from the release, the two de minimis tests, whether the release was addressed to the regulatory authority's satisfaction, and whether that was to unrestricted use criteria or with controls.

What the answer turns on

The standard's appendixes are nonmandatory. The one on the REC definition takes its examples through these questions in this order, and says the examples are illustrations that are not to be applied universally (E1527-21, X4.3).

Presence or likely presence from the release. A REC is hazardous substances or petroleum products at the subject property owing to a release, their likely presence owing to a release or a likely release, or their presence where conditions make a future release a material threat (E1527-21, 3.2.73). Not every finding indicates one of the four classes (E1527-21, 12.5).
The two de minimis tests. A de minimis condition comes from a release, generally poses no threat to health or the environment, and generally would not bring enforcement if the agencies learned of it. One judged de minimis is neither a REC nor a CREC (E1527-21, 3.2.20). In that appendix's illustration of an oil stain on a parking lot, the enforcement test is answered from the environmental professional's experience of the regulators concerned (E1527-21, X4.3). The standard names no quantity or reporting threshold for either test.
Addressed to the regulatory authority's satisfaction. A CREC and an HREC both need a release addressed to the regulatory authority's satisfaction (E1527-21, 3.2.17, 3.2.39). For a CREC the professional reviews the documents that can reasonably be had, among them a no further action letter or a like approval, or, for a self-directed action, data that satisfy the authority's risk-based criteria (E1527-21, 3.2.17.1). For an HREC the professional reviews the documents and data that show unrestricted use criteria were met (E1527-21, 3.2.39.1).
Unrestricted use criteria, or controls. An HREC meets the authority's unrestricted use criteria with no control on the subject property, and the standard does not count it as a REC (E1527-21, 3.2.39). In a CREC, substances are left in place under required controls, such as activity and use limitations (AULs) or other property use limitations; a CREC is a REC (E1527-21, 3.2.17). Either status can end on new conditions, which include a change in regulatory criteria, a migration pathway not known or evaluated before, and for a CREC a change in the property's use (E1527-21, 3.2.17.1, 3.2.39.1).

A business environmental risk is not one of the four. The standard describes it as a risk of material impact, environmental or environmentally driven, on the business that goes with a property's present or planned use, not necessarily tied to the issues the practice requires to be investigated, and says evaluating one may call for investigation beyond the practice (E1527-21, 1.1, 3.2.11).

The records that bear on it

The agency file. For a subject property or adjoining property on a standard list, the file should be reviewed for what the listing means among the four classes, or the report explains why a review is not warranted (E1527-21, 8.2.3.1).
Closure documents and controls. The owner, key site manager and user are asked for site investigation and cleanup reports, risk assessments and recorded AULs (E1527-21, 10.8.1). Registries of institutional and engineering controls are searched for the subject property (state, federal).

What the federal rule says

The rule has none of the four classes. The report it requires has to carry:

An opinion as to whether the inquiry has identified conditions indicative of releases or threatened releases of hazardous substances

40 CFR 312.21(c)(1)

How it is written up

The Opinions give the professional's reasons why a finding does or does not fall in each class it pertains to (E1527-21, 12.6).

Where the professional concludes a release has left hazardous substances or petroleum products 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, 12.7, 12.8).

Where the professional judges both de minimis tests met, the opinion says why. The Conclusions list RECs, CRECs and significant data gaps, so a de minimis condition need not appear in them (E1527-21, 3.2.20, 12.7).

Where the professional concludes the release met unrestricted use criteria with no control, and still qualifies, the opinion cites the documents and data reviewed. The Conclusions need not list an HREC (E1527-21, 3.2.39, 3.2.39.1, 12.7).

Where the professional concludes substances remain under required controls, the opinion explains how the release was addressed to the authority's satisfaction and identifies the AUL or property use limitation relied on. A CREC is a REC, and the Conclusions list it (E1527-21, 12.6.1, 12.7).

Observation of part of the subject property on the site visit 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.