A Phase 1 Environmental Site Assessment (ESA) is a report prepared by a qualified environmental professional that assesses the likelihood of contamination that could potentially impact the environment or the subject property.
They are an important part of the due diligence process for any real estate transaction.
The average cost for Phase 1 inspections ranges anywhere from $1,500 to $2900 depending on the size and complexity of the project.
A Phase 1 inspection is a thorough investigation of a property’s current and past uses, as well as identifying any recognized environmental conditions (RECs) at a property.
RECs are defined as the presence or likely presence of any hazardous substances or petroleum products on a property that could potentially negatively impact human health or the environment.
Phase 1 ESAs are typically conducted on commercial properties that are being sold, leased, or developed.
Many lenders require an ESA prior to financing to identify any environmental concerns that could potentially impact the value of the property or pose a health or safety risk to its occupants.
The ASTM E1527-13 Standard Practice for Environmental Site Assessments: Phase I ESA Process establishes the requirements for a Phase I ESA. ESA’s are conducted in accordance with procedures outlined in ASTM Standard E1527-13, which is the recognized standard used by the Environmental Protection Agency (EPA).
The purpose of a Phase I ESA is to identify recognized environmental conditions (RECs).
RECs are defined as the presence or likely presence of any hazardous substances or petroleum products on a property under conditions that indicate an existing release, past release, or material threat of a release into structures on the property or into the ground, groundwater, or surface water of the property.
A Phase I ESA does not confirm the presence or absence of contamination; rather, it assesses the potential for contamination.
Environmental site assessments are conducted in three phases:
Phase 1:
During a Phase 1 assessment, an environmental consultant will review historical records and conduct interviews with stakeholders in order to assess the potential risks associated with the property. If there is reason to believe that contamination may be present on the site, a Phase 2 assessment will be recommended.
Phase 2:
A Phase 2 assessment is conducted when there is evidence of contamination present on the site. This phase involves the collection and analysis of soil and groundwater samples in order to determine the extent of contamination present. If potentially harmful levels of contamination are found, a Phase 3 assessment will be recommended.
Phase 3:
A Phase 3 assessment is conducted when potentially harmful levels of contamination have been found on a property. This phase includes the collection and analysis of additional soil and groundwater samples, as well as the development of a risk assessment report.
The report will identify any potential health hazards posed by the contamination and recommend remediation activities that need to be undertaken in order to make the site safe for future use.
A Phase 1 ESA typically includes the following elements:
- Review of historical documentation
- Site inspection and reconnaissance
- Interviews with past and current owners, operators, occupants, and neighbors
- Review of governmental records
- A report of findings that may include information on recognized environmental conditions, as well as recommended investigation and/or remediation activities.
Here is the process in a little more detail.
Records Review:
The first step of a Phase 1 ESA is to review any available records for the property, including past environmental assessments, building permits, and historical aerial photographs.
An inspection of local, state, and federal environmental databases to determine if the property has been previously contaminated or if there are any ongoing environmental investigations or cleanup activities taking place in the vicinity of the property.
Site Observations:
A visual inspection of the property for obvious signs of contamination, such as strong odors, spills, or staining.
This may involve activities such as walking the site, observing conditions, and interviewing adjacent property owners or occupants.
Interviews:
Discussions with current and former owners, occupants, and neighbors about their knowledge of any past contamination at or near the property.
Researching Regulatory Databases:
In this step, databases such as the Hazardous Substances Data Bank (HSDB), Toxic Release Inventory (TRI), and Superfund Registry are searched in order to determine if any hazardous substances have been reported at or near the site in question.
Preparation of Health and Safety Plan:
Once all information has been gathered, a health and safety plan is prepared.
This plan outlines the specific health and safety hazards that may be present on the property and outlines the protocols that will be followed during the assessment process to protect workers from these hazards.
Final Report:
After collecting all of this data, the inspector will prepare a report that details their findings that includes recommendations for addressing any identified contamination risks and recommendations for further action, if necessary.
If the Phase 1 ESA identifies any areas of potential concern, a Phase 2 ESA may be conducted to gather more information.
A Phase 2 ESA typically includes indoor air quality (IAQ) testing, drilling or excavating to collect samples of soil and groundwater, as well as testing for hazardous materials such as asbestos and lead.
If you are considering purchasing a piece of property, it is important to have a Phase 1 Environmental Site Assessment (ESA) conducted in order to avoid any potential environmental liabilities and avoid costly surprises down the road.
Call 619-473-2133 for a free quote.

Maurice is the Chief Inspector for U.S. Commercial Building Inspections of Southern California. He is a Certified Commercial Property Inspector (CCPI) and brings over 25 years of extensive experience in real estate, construction, restoration, remediation, and business development.
Do you need an inspection? Call 619-473-2133 for a free quote.