What Is a Phase II Environmental Site Assessment and When Do You Need One?

When buying, selling, or developing commercial property—especially those with underground storage tanks or a history of industrial use—environmental due diligence is essential.

While a Phase I ESA helps identify potential environmental risks, it doesn’t include testing or sampling. If red flags are raised, the next step is a Phase II Environmental Site Assessment (ESA).

At Adelphi Environmental, we guide our clients through this process—from initial risk identification to sample collection, lab analysis, and remediation recommendations. If you're unsure whether a Phase II is required—or what it even entails—this guide breaks it down.

What Is a Phase II ESA?

A Phase II ESA is a targeted investigation that uses soil, groundwater, and vapor sampling to confirm whether environmental contamination exists on a property.

It’s based on concerns identified in a Phase I ESA, such as:

• Recognized Environmental Conditions (RECs)

• Historical use of hazardous materials

• Proximity to known spill sites or dry cleaners

• Former or existing USTs, fuel dispensers, or auto shops

The goal? Determine the presence, extent, and type of contamination—and assess potential health or regulatory risks.

What Does a Phase II ESA Involve?

Every site is different, but a Phase II ESA generally includes:

✅ Soil Sampling

Boring or test pits are used to collect soil samples from depths of concern (usually near USTs, dispensers, or former storage areas).

✅ Groundwater Sampling

Monitoring wells may be installed to test for contaminants like petroleum hydrocarbons, solvents, or heavy metals.

✅ Vapor Intrusion Assessment

Air sampling may be conducted to test indoor air quality or vapor migration from soil/groundwater sources.

✅ Laboratory Analysis

All samples are analyzed by certified labs using EPA-approved methods.

✅ Final Report & Interpretation

The results are compiled into a detailed report with:

• Contaminant levels and comparisons to regulatory thresholds

• Risk assessment

• Recommendations for remediation or next steps

When Is a Phase II ESA Needed?

You may need a Phase II ESA when:

• A Phase I ESA identifies RECs (e.g., tanks, spills, historical use)

• A lender or buyer requests testing to confirm environmental soundness

• A regulatory agency requires investigation based on reported use or permits

• You’re preparing for redevelopment or change of use (especially for schools, healthcare, residential)

  
  

Why It Matters for Real Estate and Development

A Phase II ESA can significantly impact:

• Property value and insurance

• Financing approvals and lender requirements

• Liability protection under CERCLA (Superfund laws)

• Construction timelines and permitting

It provides legal protection for the buyer, transparency for the seller, and a clear path forward for developers.

How Adelphi Supports You Through the Process

At Adelphi Environmental, we take the guesswork out of site assessments. Our team provides:

• Fast, compliant sampling and lab coordination

• Clear, jargon-free reporting and risk summaries

• Strategic remediation planning, if contamination is found

• Coordination with regulators, lenders, and legal teams

Whether you’re managing a single site or multiple properties, we tailor the process to your goals and timelines.

Need Clarity on Your Site's Environmental Risk?

If your Phase I ESA has flagged concerns—or you're just starting due diligence—Adelphi can help you take the next step confidently.

Schedule a Phase II ESA consultation today and make informed, risk-aware decisions about your property.