What Is a Phase I Environmental Site Assessment?

Before closing on a property or beginning site design, Florida developers must consider more than zoning and soil—they must also investigate environmental risks. That’s where the Phase I Environmental Site Assessment (ESA) comes in.

In this post, RSP Engineers outlines what a Phase I ESA includes, why it’s often required by lenders and municipalities, and how it can make or break your development timeline.

What Is a Phase I ESA?

A Phase I ESA is a due diligence process that investigates the past and current use of a property to identify potential or existing environmental contamination. It follows the ASTM E1527-21 standard and is often conducted before the purchase of commercial or industrial real estate.

The purpose is to determine if there are any Recognized Environmental Conditions (RECs) that may pose liability or cleanup costs to the property owner.

What a Phase I ESA Includes

A licensed environmental professional performs the assessment, which typically includes:

Component	Description
Records review	Review of state and federal databases, property records, maps, and aerial photos
Site inspection	Visual assessment of the property for signs of contamination or distressed vegetation
Interviews	Discussions with past and current owners, occupants, or local agencies
Historical research	Review of historical uses that could have involved hazardous materials (e.g., gas stations, dry cleaners)
Report findings	A detailed summary of findings and whether further investigation is recommended

Why Phase I ESA Matters in Florida

Florida’s long industrial history and high groundwater table increase the risk of encountering environmental issues, particularly in areas that were:

• Former industrial or agricultural lands

• Near petroleum storage tanks

• Used as landfills or waste disposal sites

• Previously remediated for contamination

A Phase I ESA helps developers avoid liability under CERCLA (Superfund) and can reveal hidden risks that impact permitting or resale.

What Happens If Issues Are Found?

If the Phase I ESA identifies a Recognized Environmental Condition (REC), the next step is a Phase II ESA, which involves sampling and testing of soil, groundwater, or building materials.

Depending on findings, site cleanup (remediation) may be required before development or even sale.

Does Every Project Need One?

Not always—but most lenders, particularly for commercial real estate transactions, require a Phase I ESA to approve financing. It’s also highly recommended for:

• Property purchases

• Redevelopment of brownfields

• Projects near industrial zones

• Public-private partnerships or federally funded projects

Conclusion

A Phase I Environmental Site Assessment isn’t just a box to check—it’s a critical tool for protecting your investment and ensuring regulatory compliance. Whether you're planning new construction or buying land in Florida, don’t overlook this essential step.

Looking for Civil + Environmental Due Diligence Support?

RSP Engineers delivers civil engineering and environmental services across Florida. Contact us for comprehensive land development support—from soil reports to stormwater permitting.

FAQs

• Is a Phase I ESA required by law in Florida?

  No, it’s not legally required—but it is a standard part of due diligence and usually required by lenders and municipalities. Learn more from EPA’s Brownfields Program.

• How long does a Phase I ESA take?

  Typically 2–3 weeks, depending on the complexity and availability of historical records.

• What’s the difference between Phase I and Phase II ESA?

  Phase I involves research and observation. Phase II includes physical sampling and laboratory analysis.

• Who pays for the Phase I ESA?

  The buyer or developer typically covers the cost as part of the property due diligence process.

• Can you skip a Phase I ESA for residential projects?

  It depends on the location and scope. While not common for small residential builds, it may be necessary in areas with prior industrial use.

Work with Geotechnical Experts in Florida

RSP Engineers offers comprehensive site evaluations and soil analysis for projects across Florida. We provide design and permitting support to navigate organic soils with confidence. Contact our team to get started.