Phase 1 Environmental Site Assessment

A Phase 1 Environmental Site Assessment, also called a Phase I ESA, is an environmental due diligence report used before buying, financing, refinancing, or redeveloping commercial property. The goal is to identify whether current or historical property uses may have caused contamination or environmental liability.

Phase 1 ESAs are commonly required by lenders, SBA lenders, attorneys, and commercial real estate buyers before closing. The assessment follows the ASTM E1527-21 standard, which defines the scope, process, and reporting requirements. It is entirely non-invasive. No soil, water, or air samples are collected. If contamination indicators are found, a Phase 2 ESA with physical testing may be recommended.

When a Phase 1 ESA Is Required

Most commercial property transactions involve a Phase 1 ESA at some point. The following situations typically trigger one:

• Commercial real estate purchases. Buyers use Phase 1 ESAs to evaluate environmental risk before closing. Lenders almost universally require one.
• SBA loans. The Small Business Administration requires environmental review for loans involving real property. Phase 1 ESAs satisfy this requirement for most property types.
• Refinancing. Lenders refinancing commercial property often require an updated Phase 1 ESA, particularly if the existing report is more than 180 days old.
• Property development. Developers order Phase 1 ESAs before breaking ground to avoid discovering contamination mid-project.
• Portfolio acquisitions. Investors acquiring multiple properties will typically order Phase 1 ESAs across the entire portfolio.
• Foreclosures and REO properties. Banks and lenders managing foreclosed properties use Phase 1 ESAs to assess environmental liability before resale.

Who Orders Phase 1 ESAs

• Commercial property buyers
• Banks and lenders
• SBA borrowers
• Developers
• Real estate attorneys
• Investors
• Property owners refinancing commercial property
• Buyers of industrial, retail, warehouse, automotive, dry cleaning, or multifamily properties

If you fall into any of these categories, you can find ESA service providers through our network.

What a Phase 1 ESA Includes

A Phase 1 ESA conducted under ASTM E1527-21 includes four core components:

1. Records Review

The environmental professional reviews historical records to understand past uses of the property and surrounding area. This includes aerial photographs, fire insurance maps (Sanborn maps), city directories, building permits, and land title records. The goal is to identify any historical activity that could have caused contamination.

2. Regulatory Database Review

Federal, state, tribal, and local environmental databases are searched for records of contamination, spills, underground storage tanks, hazardous waste generators, and enforcement actions. The search covers the subject property and nearby properties within specified distances defined by ASTM.

3. Site Reconnaissance

An environmental professional physically visits the property and walks the site. They look for evidence of current or past contamination, including stained soil, chemical odors, drums or containers, aboveground and underground storage tanks, floor drains, electrical transformers, and waste disposal areas.

4. Interviews

The environmental professional interviews current and past owners, operators, and occupants of the property. They also interview local government officials to gather information about the property history and any known environmental issues.

What a Phase 1 ESA Does Not Include

A Phase 1 ESA does not include soil testing, groundwater testing, asbestos surveys, lead-based paint surveys, mold inspections, wetlands delineations, structural inspections, or compliance audits unless separately requested. It is designed to identify potential environmental concerns based on records, interviews, and visual observations. If the Phase 1 identifies a Recognized Environmental Condition, a Phase 2 ESA may be recommended.

What the Report Delivers

The final Phase 1 ESA report documents all findings and classifies any environmental concerns using three categories defined by ASTM:

• Recognized Environmental Conditions (RECs). Conditions that indicate an existing release, a past release, or a material threat of a release of hazardous substances into the ground, groundwater, or surface water of the property.
• Controlled Recognized Environmental Conditions (CRECs). Past releases that have been addressed but remain on the property subject to controls (such as engineering or institutional controls).
• Historical Recognized Environmental Conditions (HRECs). Past releases that have been addressed and meet unrestricted residential use criteria, with regulatory closure documentation.

If no RECs are identified, the report provides a clean opinion supporting the buyer's "innocent landowner" defense under CERCLA (the Superfund law). This defense protects buyers from liability for pre-existing contamination they did not cause.

For a full breakdown of report sections, see our ESA report guide.

Timeline and Process

A standard Phase 1 ESA takes 2 to 4 weeks from authorization to delivery. The timeline breaks down roughly as follows:

• Week 1: Database searches ordered, records review begins, site visit scheduled.
• Week 2: Site reconnaissance conducted, interviews completed.
• Weeks 3-4: Report drafted, reviewed by a senior environmental professional, and delivered.

Rush turnaround is available from most firms, typically in 5 to 10 business days, for an additional fee. Rush reports follow the same ASTM standard and carry the same legal weight.

How Much a Phase 1 ESA Costs

Phase 1 ESA pricing typically ranges from $1,500 to $6,000 depending on the property type, location, size, and complexity. Straightforward commercial properties (offices, retail) tend toward the lower end. Larger sites, properties with complex industrial history, or properties in areas with extensive regulatory records cost more.

Factors that affect pricing include:

• Property size and acreage
• Number of buildings or structures
• Historical use (industrial vs. commercial vs. undeveloped)
• Location and travel distance for the site visit
• Density of nearby contaminated sites in regulatory databases
• Rush turnaround requirements

For a detailed pricing breakdown, see our Phase 1 ESA cost guide.

Phase 1 ESA vs. Phase 2 ESA

A Phase 1 ESA is a records-based, non-invasive assessment. No physical testing is performed. A Phase 2 ESA involves collecting and analyzing soil, groundwater, or soil vapor samples to confirm or rule out contamination identified in the Phase 1.

A Phase 2 is only needed when the Phase 1 identifies RECs that require further investigation. Not every Phase 1 leads to a Phase 2. For a full comparison, see our Phase 1 vs. Phase 2 guide.

The ASTM E1527-21 Standard

ASTM E1527-21 is the current standard of practice for Phase 1 ESAs, replacing the previous E1527-13 version. It was updated in 2021 to address emerging contaminants (including PFAS), clarify the role of regulatory agency file reviews, and refine the definition of environmental professionals.

Any Phase 1 ESA used to satisfy the CERCLA innocent landowner defense or All Appropriate Inquiries (AAI) rule must comply with this standard. Reports conducted under older versions may not be accepted by lenders or regulators.

For more on the standard, see our ASTM E1527-21 guide.

Who Performs Phase 1 ESAs

Phase 1 ESAs must be conducted or supervised by an "environmental professional" as defined by ASTM E1527-21 and the EPA's All Appropriate Inquiries rule. This typically means a licensed professional engineer (PE) or professional geologist (PG) with relevant environmental experience, or a person with equivalent qualifications through education and experience.

Environmental consulting firms employ these professionals and handle the full process from database searches through final report delivery.

Shelf Life of a Phase 1 ESA Report

Under ASTM E1527-21, a Phase 1 ESA report is considered current for 180 days from the date of the report. After 180 days, certain components must be updated before the report can be relied upon for a transaction. After one year, a completely new Phase 1 ESA is generally required.

Lenders may impose stricter timelines. Some require reports less than 90 days old at closing.

Get Phase 1 ESA Quotes

ESAquotes connects property buyers, lenders, and developers with environmental professionals who perform Phase 1 ESAs nationwide. Submit your property details and receive competitive quotes from licensed firms in your area.