Glossary

Restrictions placed on how a property may be used or occupied after contamination has been addressed, typically where residual contamination remains in place. A property carrying an AUL, or an institutional or engineering control, commonly involves a controlled recognized environmental condition rather than a closed one.

REC, CREC, HREC, or BER? A Practical Guide to Environmental Risk Classification →

A property bordering the subject property. A Phase I ESA evaluates adjoining and nearby properties as well as the subject property itself, because a release on a neighboring site can present a concern to the property being assessed depending on distance, direction, topography and groundwater conditions.

Phase I ESA Explained: What Commercial Real Estate Buyers Need to Know →

The US EPA describes All Appropriate Inquiries as the process of evaluating a property's environmental conditions and assessing potential liability for any contamination. The AAI Final Rule is codified at 40 CFR Part 312.

EPA recognizes ASTM E1527-21 as consistent with the AAI requirements, which is why Phase I ESAs in the United States are commonly performed to that standard.

Phase I ESA Explained: What Commercial Real Estate Buyers Need to Know →Source: US EPA

Standard Practice for Environmental Site Assessments: Phase I Environmental Site Assessment Process. It is intended to identify recognized environmental conditions associated with a property and to provide a framework for conducting appropriate environmental inquiry.

It is the standard our Phase I ESA support is prepared to work with, alongside whatever additional requirements a client's own scope adds.

Phase I ESA Explained: What Commercial Real Estate Buyers Need to Know →

The standard practice behind Transaction Screen Assessments and desktop reviews, both of which are lighter-touch alternatives to a full Phase I ESA. We have delivered assessments under this standard as well as under E1527.

The baseline framework for Property Condition Assessments of commercial real estate. The process includes a walk-through survey, document review, research and interviews, with the resulting Property Condition Report incorporating observations and opinions of cost for suggested remedies.

It describes a baseline. The appropriate level of assessment may vary with the property's characteristics, the transaction requirements, risk tolerance, schedule and budget.

Property Condition Assessment (PCA): What Commercial Real Estate Investors Should Know →

A property whose expansion, redevelopment or reuse may be complicated by the presence or potential presence of contamination. EPA's Brownfields program provides grants and technical assistance to assess, clean up and reuse such properties.

Brownfield program listings are one of the regulatory database sets reviewed during environmental database research.

Source: US EPA

An environmental issue that can affect a property's value, marketability, use or transaction, but which falls outside the definition of a recognized environmental condition. ASTM E1527-21 recognizes that certain business environmental risks may require evaluation beyond the standard Phase I ESA scope.

Examples include asbestos-containing materials, lead-based paint, radon, mold, regulatory compliance issues, emerging contaminants and historical uses with no evidence of a release.

REC, CREC, HREC, or BER? A Practical Guide to Environmental Risk Classification →

The Comprehensive Environmental Response, Compensation, and Liability Act, enacted in 1980 and commonly known as Superfund. It authorizes short-term removal actions to address releases or threatened releases requiring prompt response, and long-term remedial actions.

CERCLA and Superfund site listings are among the databases reviewed during environmental database research.

Source: US EPA

Review of historical city directories to establish who occupied a property, and what they did there, across the decades a Phase I ESA looks back over. One of the standard historical sources, alongside aerial photographs, topographic maps and Sanborn maps.

Why Historical Property Research Is Critical in a Phase I ESA →

A CREC generally applies where a REC has been addressed through remediation or other response activities, but residual contamination remains subject to activity and use limitations or institutional and engineering controls.

REC, CREC, HREC, or BER? A Practical Guide to Environmental Risk Classification →

Repair and maintenance items that have been postponed. A Property Condition Assessment separates deferred maintenance from immediate repair needs and from longer-term capital requirements, because deferred maintenance can increase future repair costs if it is not addressed.

Property Condition Assessment (PCA): What Commercial Real Estate Investors Should Know →

A records-based environmental review carried out without a site visit, delivered under ASTM E1528-14. One of the assessment types we have delivered, alongside Phase I ESAs, transaction screen assessments and record search and risk assessments.

Review of federal, state, tribal and local environmental databases to identify facilities and properties associated with regulatory programs: UST and LUST, RCRA, CERCLA and Superfund, brownfields, state remediation programs, spill and petroleum release databases and hazardous waste programs.

Listings are not simply reported. They are evaluated on location, distance, direction, regulatory status, release information, groundwater conditions and potential migration pathways.

When Does an Environmental Database Listing Become a REC? →

The inferred direction groundwater moves beneath a property. It determines whether a nearby release site sits hydraulically upgradient or downgradient of the subject property, which is often the difference between a listing that matters and one that does not.

How Groundwater Flow, Topography, and Soil Conditions Affect Environmental Risk →

A past release of hazardous substances or petroleum products that has been addressed to the satisfaction of the applicable regulatory authority and does not represent a current REC. The historical release stays relevant to the property's environmental history even though the condition may not be a current REC.

REC, CREC, HREC, or BER? A Practical Guide to Environmental Risk Classification →

Physical deficiencies identified in a Property Condition Assessment that may require prompt attention, as distinct from deferred maintenance and from future capital expenditure.

Property Condition Assessment (PCA): What Commercial Real Estate Investors Should Know →

A UST system from which a release has been confirmed, whether by leak, spill or overfill. EPA reports 583,313 confirmed releases from UST systems as of March 2026, and notes that gasoline leaking from service stations is one of the most common sources of groundwater pollution.

A LUST listing near a property is evaluated on distance, direction, topography, groundwater conditions, site history, regulatory status and the available release information before it is treated as a concern.

How to Evaluate Gas Stations, USTs, and LUSTs During a Phase I ESA →Source: US EPA

Environmental concerns outside the scope of the REC definition in ASTM E1527-21, such as asbestos-containing materials, lead-based paint, radon and mold. They are evaluated where the client's scope asks for them.

REC, CREC, HREC, or BER? A Practical Guide to Environmental Risk Classification →

An environmental due diligence assessment conducted to evaluate the potential for recognized environmental conditions associated with a commercial property. It combines historical research, environmental database review, regulatory records review, site reconnaissance and interviews.

It is a research and observational assessment. It does not generally include soil, groundwater or soil vapor sampling, laboratory analysis, subsurface investigation or remediation.

Phase I ESA Explained: What Commercial Real Estate Buyers Need to Know →

An investigation involving physical sampling to evaluate whether suspected contamination is actually present. It may be appropriate where a Phase I ESA identifies a condition that cannot be adequately evaluated through available records and visual observations.

It is not an automatic consequence of every REC. The recommendation should be tied to the specific source, pathway, contaminant, data gap and transaction objectives.

Phase I ESA vs. Phase II ESA: When Is Additional Investigation Necessary? →

A commercial real estate due diligence assessment used to evaluate the physical condition of a property's improvements and identify material physical deficiencies and potential repair or capital needs. It answers a different question from a Phase I ESA: physical condition rather than environmental risk.

PCA vs. Phase I ESA: Why Both Matter in Commercial Real Estate Due Diligence →

The Resource Conservation and Recovery Act, which gives EPA authority to control hazardous waste from cradle to grave: generation, transportation, treatment, storage and disposal. It covers hazardous waste under Subtitle C and non-hazardous solid waste under Subtitle D.

RCRA facility listings are one of the database sets reviewed during environmental database research.

Source: US EPA

Under ASTM E1527-21, a REC generally relates to the presence of hazardous substances or petroleum products due to a release, the likely presence due to a release or likely release, or conditions posing a material threat of a future release.

A database listing does not automatically mean a REC exists. The environmental professional evaluates distance, direction, topography, groundwater conditions, site history, regulatory status and available release information first.

When Does an Environmental Database Listing Become a REC? →

A records-based environmental assessment prepared under the US Small Business Administration's SOP 50-10 requirements, used in SBA lending. One of the assessment types we have delivered.

A determination by the applicable regulatory authority that a release has been addressed and no further action is required. An active remediation case may warrant greater consideration in a Phase I ESA than a site that has received regulatory closure.

When Does an Environmental Database Listing Become a REC? →

Detailed historical maps produced for fire insurance underwriting, showing building footprints, construction and use. Where available, they are among the most informative historical sources for identifying former industrial operations, fuel storage and other uses of environmental significance.

Why Historical Property Research Is Critical in a Phase I ESA →

The visual inspection component of a Phase I ESA. A current site reconnaissance may show no obvious environmental concerns even where historical research identifies significant past uses, which is why the two are evaluated together.

Phase I ESA Explained: What Commercial Real Estate Buyers Need to Know →

The property being assessed, as distinct from the adjoining and nearby properties that are also evaluated for conditions that could affect it.

A limited-scope environmental screening under ASTM E1528-14, lighter than a Phase I ESA. One of the assessment types we have delivered.

EPA defines a UST system as a tank, or combination of tanks, and connected underground piping having at least 10 percent of their combined volume underground. Federal UST regulations apply to systems storing petroleum or certain hazardous substances.

Former and current USTs are among the most common findings in commercial property due diligence, particularly at gas stations, vehicle repair facilities and older industrial sites.

How to Evaluate Gas Stations, USTs, and LUSTs During a Phase I ESA →Source: US EPA