Get 3 quotes for your Phase 1 Environmental Site Assessment

Independent · covers all 50 states

An independent resource for commercial real estate buyers, lenders, and developers who need a Phase 1 Environmental Site Assessment. Compare providers, see real cost data by state, and request quotes in minutes.

Get 3 quotes for your Phase 1 ESA

Step 1 of 2

Free to use, with no obligation to hire. Review the Privacy Policy.

See the full cost-by-state data · Browse by state

What is a Phase 1 Environmental Site Assessment?

A Phase 1 Environmental Site Assessment (Phase 1 ESA) is a non-intrusive investigation into a commercial property's environmental history: records review, a site visit, and interviews, built to identify whether the property carries contamination risk from a past use. No soil or groundwater samples are collected in a Phase 1; that only happens in a follow-up Phase 2 ESA if the Phase 1 finds a reason to look closer.

It matters because of CERCLA, the federal Superfund law. A new property owner can be held liable for cleanup costs tied to contamination that happened before they owned the property, even if they had nothing to do with causing it. Completing a Phase 1 ESA to the ASTM E1527-21 standard before you buy is how a buyer, lender, or developer qualifies for innocent landowner or bona fide prospective purchaser protection under the EPA's All Appropriate Inquiries rule.

Almost every commercial lender requires one before funding a purchase or refinance. Standard turnaround is 2 to 4 weeks, and cost typically runs $2,000 to $4,500 depending on property size, history, and state.

Guides and resources

A starting spread across cost, timing, property types and picking a provider.

What Is a Phase 1 Environmental Site Assessment?

A Phase 1 ESA is a non-intrusive investigation into a property's environmental history, built to identify contamination risk before you buy, lend on, or develop it.

Phase 1 vs Phase 2 ESA: What's the Difference?

A Phase 1 ESA asks whether a property is at risk of contamination through records and observation. A Phase 2 ESA answers that question with actual soil, groundwater, or building material testing, and it only happens when Phase 1 finds a reason to look closer.

How Long Does a Phase 1 ESA Take?

A standard Phase 1 ESA takes 2 to 4 weeks from authorization to final report, broken into records review, a site visit, interviews, and report writing, with rush options usually available for a fee.

Phase 1 ESA for Gas Stations and Former Fuel Sites

Current and former gas stations carry one of the highest cost premiums and REC rates of any property type, driven by underground storage tank history and petroleum contamination risk.

How to Choose a Phase 1 ESA Provider

Vet the signing environmental professional's qualifications, ask what the quoted price actually includes, and get a firm turnaround commitment tied to your closing date.

Phase 1 ESA Checklist for First-Time Commercial Buyers

If this is your first commercial purchase, here's the practical order of operations: order early, confirm your lender's requirements, vet the provider's credentials, and track the 180-day report clock.

See all 21 guides, grouped by topic

Phase 1 ESA cost by state, 2026

A Phase 1 ESA costs $2,000 to $4,500 nationally in 2026 (average $3,250), but the number moves by state, from about $1,600 in the lowest-cost states to over $6,500 in the highest. See the full 50-state cost table, standard turnaround time, and property-type premiums, every figure compiled from published industry sources with citations.

See the data