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Phase I 
Environmental Site Assessments

ASTM E1527-21

What is a Phase I Environmental Assessment?

Scope of work that can identify potential or existing environmental contamination liabilities. A Phase I Environmental Site Assessment, commonly referred to as an ESA, or Phase I ESA is completed by researching current and historical uses of a property as part of a commercial real estate transaction.

Why is a Phase I ESA important?

Besides liability, it can determine if a property is a Recognized Environmental Concern (REC), Controlled Recognized Environmental Concern (CREC), Historical Recognized Environmental Concern (HREC), De minimis Condition, or Business Environmental Risk (BER). This can save money on legal issues and avoids the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Also, it's the first step prior to determining if the Property needs further action such as performing Phase II. 

Scope of Work

Site Visit

  • Inspection of the Site by one of our professionals.

  • Footage of complete property pertaining Environmental concerns and standard review. 

  • Drone Inspection if necessary.

Regulatory Research

  • Fire Department 

  • State Environmental Agencies

  • Federal Environmental Agencies

Historical Review

  • Historical Aerials Photographs

  • Street Directories

  • Sanborn Fire Insurance Maps

  • Topographic Maps

  • Building Permits

  • Planning Records

  • Department of Oil and Gas Map

  • Parcel and Tax Information 

  • Interviews

Non-Scope Considerations

  • Asbestos

  • Lead 

  • Radon

  • Mold

Geology and Hydrology

  • Soil Type

  • Geological Settings

  • Groundwater depth

Findings, Conclusions and Recomendations

  • Review of Regulatory Environmental Data Report

  • Conclusion of property

  • Recommendation as necessary by our Environmental Professionals.

Dictionary of Phase I Environmental According to ASTM E1527-21

The changes from the 2013 to 2021 ASTM standards did not significantly alter the Phase I Environmental Site Assessment report or process, but there are a few key changes you should be aware of. The most significant changes include:

Historical Research – The E1527-21 now requires the review of at least the “Big 4” historical sources (aerial photographs, topographic maps, fire insurance maps, and city directories) for both the subject property and its adjoining properties. If a Big 4 resource was not reviewed, the EP must explain why the review was not completed and may need to review additional resources. Additionally, if the subject property’s use is industrial, manufacturing, and (now) retail, the review of additional resources (building department records, property tax files, interviews, and zoning), may be needed.


Recognized Environmental Condition (REC): the presence or likely presence of any hazardous substances or petroleum products in, on, or at a property: (1) due to any release to the environment; (2) under conditions indicative of a release to the environment; or (3) under conditions that pose a material threat of a future release to the environment.

Controlled REC (CREC): a past release of hazardous substances or petroleum products that have been addressed to the satisfaction of the applicable regulatory authority, with hazardous substances or petroleum products allowed to remain in place subject to the implementation of required controls.

Historical REC (HREC): historical documents help to understand past property uses, and whether past tenants could have contaminated the property. The past presence of hazardous substances or petroleum products in, on, or at the property, is considered a historical REC.

De Minimis Condition: a condition related to a release that generally does not present a threat to human health or the environment and that generally would not be the subject of an enforcement action if brought to the attention of appropriate governmental agencies.

Emerging Contaminants: The new standard has added PFAS and other emerging contaminants to the list of “non-scope issues” that a user may want to evaluate as a business risk, as is commonly done with asbestos and mold. Until EPA classifies PFAS as a hazardous substance, it cannot be considered a REC within the constructs of an ESA. 

Business Environmental Risk (BER): a risk that can have a material environmental or environmentally-driven impact on the business associated with the current or planned use of the commercial real estate, not necessarily related to those environmental issues required to be investigated in this practice.

Recognized Environmental Condition (REC)

Some RECs are required to be reported and cleaned under agency oversight, while others may not; but

the owner’s liability remains. Some examples of RECs are:

  • known or suspected releases due to spills and leaking storage tank

  • accumulation of incidental spills, suspected or known, over an extended period

  • known or suspect underground storage tanks (USTs)

  • current or historical use of hazardous substances

Controlled REC (CREC)

The property owner is responsible for any soil and groundwater contamination, whether known or unknown. However, an ESA fulfills a due diligence environmental investigation, thereby putting the burden of the cost of current and future remediation on the responsible party or state agency. Some examples of CRECs are:

  • Soil and groundwater are contaminated, but safe to operate a commercial business. The use of groundwater is not permitted.

  • Safe for commercial business only, excavation or movement of soil is not permitted without government permission.

  • Soil and groundwater undergoing remediation through mechanical or natural attenuation with no current permitted use.

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