ESA key terms

The statutory standard under CERCLA for investigating a property's environmental conditions before acquisition, required to preserve certain liability protections. ASTM E1527 practice satisfies this standard when conducted by an environmental professional.

A party who acquires property after January 11, 2002, knowing it is contaminated, yet avoids CERCLA owner liability by conducting AAI, exercising appropriate care, and complying with continuing obligations and institutional controls.

A CERCLA liability protection for an owner who acquired property without knowledge of contamination after performing all appropriate inquiries and exercising due care, typically relying on pre-acquisition investigation findings.

A CERCLA liability protection for an owner of property contaminated solely by a neighboring source, available when the owner did not cause or contribute to the release and meets AAI and continuing obligation requirements.

The consensus standard defining Phase I Environmental Site Assessment practice, covering records review, site reconnaissance, interviews, and reporting, designed to identify recognized environmental conditions and satisfy all appropriate inquiries.

The presence or likely presence of hazardous substances or petroleum products at a property under conditions indicating an existing release, past release, or material threat of release into structures or the environment.

A past release that has been addressed to the satisfaction of a regulatory authority, with hazardous substances remaining in place under an implemented control such as an institutional control or engineering barrier.

A past release that has been fully resolved to the satisfaction of the applicable regulatory authority, with no residual hazardous substances remaining and no controls or restrictions required.

A condition that generally does not present a threat to human health or the environment and would not be the subject of an enforcement action, such as a small surface stain unrelated to a release.

A condition, activity, or risk that may affect the purchase, use, or value of a property but falls outside the scope of a recognized environmental condition, such as asbestos or vapor intrusion concerns.

A person meeting defined education and experience criteria, such as a licensed engineer or geologist or a qualified environmental scientist, who directs and supervises the inquiry and signs the Phase I report.

The tasks the property purchaser must perform under the standard, including providing specialized knowledge, prior reports, title and lien information, and identifying the reason for the assessment and intended use.

A situation where standard historical sources are unavailable or insufficient to document a property's use history, requiring the environmental professional to document the gap and the efforts made to fill it.

The defined set of records, including aerial photographs, fire insurance maps, city directories, topographical maps, and building department records, used to reconstruct a property's past uses and occupants.

Detailed historical maps produced for fire insurance underwriting that show building footprints, construction materials, occupancy, and storage of hazardous materials, often revealing past industrial uses.

A visual inspection of the property and adjoining areas conducted during a Phase I assessment to observe current conditions, potential contamination indicators, and uses that may pose environmental risk.

The migration of volatile chemicals from contaminated soil or groundwater into overlying buildings through foundations or utility pathways, potentially exposing occupants to indoor air contamination.

An investigation involving sampling and analysis of soil, groundwater, soil vapor, or building materials to confirm or evaluate conditions identified during a Phase I assessment, often used to quantify contamination.

A written strategy specifying sampling locations, depths, media, analytical methods, quality assurance procedures, and data quality objectives to ensure results reliably answer investigation questions.

Clearly defined goals for the type, quantity, and quality of data needed to support a decision, guiding sampling design, analytical method selection, and interpretation of results.

The planned and systematic activities ensuring environmental data meet stated requirements, including chain of custody, field blanks, duplicates, calibration, and laboratory certification documentation.

A documented record tracking sample possession from collection through laboratory analysis, including signatures, dates, and times, used to demonstrate sample integrity and support the admissibility of results.

A borehole installed with casing and screen at a selected depth to allow collection of representative groundwater samples and measurement of water levels for contaminant detection and plume mapping.

Collection of subsurface gas samples, often using probes or implants, to evaluate volatile organic compounds that may migrate into buildings and pose inhalation risks.

Organic chemicals with high vapor pressure that readily evaporate at ambient temperatures, commonly found in fuels, solvents, and degreasers, and frequently the focus of vapor intrusion investigations.

A liquid contaminant, such as gasoline or diesel fuel, that is less dense than water and floats on the water table, forming a separate phase that can dissolve and spread dissolved contamination.

A liquid contaminant, such as chlorinated solvent, that is denser than water and can sink below the water table, accumulating in low-permeability zones and acting as a long-term source of dissolved contamination.

The introduction of dissolved or separate-phase chemicals into subsurface water, which can migrate with flow and affect downgradient receptors such as wells, surface water, and drinking water supplies.

The three-dimensional extent of dissolved contamination in groundwater or soil gas, shaped by source location, groundwater flow direction, dispersion, and attenuation processes.

The processes that determine how contaminants move and change in the environment, including advection, dispersion, sorption, volatilization, biodegradation, and chemical transformation.

A non-engineered restriction such as an environmental covenant, zoning limitation, or well prohibition used to prevent exposure to residual contamination and maintain the effectiveness of a remedy.

Post-acquisition duties required to maintain liability protections, including complying with land use restrictions, taking reasonable steps to prevent exposure, and providing cooperation and access to regulators.

The investigation and analysis a purchaser performs before a transaction to identify environmental liabilities, regulatory obligations, and business risks, informing price, contract terms, and risk allocation.

A written regulatory determination that investigation or remediation is complete and no additional action is required, often supporting an HREC determination or closure documentation.

The formal conclusion by an environmental agency that a release has been addressed under applicable cleanup standards, potentially with residual contamination subject to controls or monitoring requirements.

Environmental issues outside the standard's scope but often evaluated for business risk, including asbestos, lead-based paint, mold, wetlands, radon, and vapor intrusion concerns.

A non-intrusive investigation of a property's current and historical uses, records, and conditions intended to identify recognized environmental conditions and support all appropriate inquiries before acquisition.

The systematic review of past property uses, owners, and occupants through maps, directories, aerial photographs, and records to identify former activities that may have caused contamination.

The preparation of a clear, defensible Phase I or Phase II report documenting methodology, findings, data gaps, conclusions, and supporting evidence, signed by the responsible environmental professional.