Checklist · Environmental

Phase I Environmental Site Assessment and All Appropriate Inquiries: A Practical Checklist

42 U.S.C. § 9607(a)

Type
Checklist
Jurisdiction
National
Date
2024-06-08
Topic
Environmental

A Phase I Environmental Site Assessment is not a formality — it is the evidentiary predicate for CERCLA's landowner defenses, and a buyer who skips it or botches it can inherit strict, joint and several, retroactive cleanup liability for contamination it did nothing to create. This checklist walks the transaction from the first scoping call through post-closing compliance: why the Phase I exists, how to engage an "environmental professional" who actually meets the regulatory definition, the user's own non-delegable duties under 40 C.F.R. §§ 312.28–312.31, the required components (records, historical use, database search, reconnaissance, interviews, report), how to read RECs, HRECs, and CRECs, the 180-day and one-year shelf-life rules, and when to escalate to Phase II sampling. It closes with the step most buyers forget: the continuing obligations under 42 U.S.C. § 9601(40) that must be satisfied *after* closing, forever, or the defense evaporates. Environmental law is federal, but state transfer statutes and cleanup programs add their own requirements — confirm yours. A consolidated one-glance checklist and full primary authority are included.

Phase I Environmental Site Assessment and All Appropriate Inquiries: A Practical Checklist

Environmental > Environmental Due Diligence | Published 8 June 2024 - Updated 21 October 2025 | UpLaw - uplaw.us

A Phase I is not an inspection. It is a legal defense, assembled in advance, and it fails the way defenses fail: not because the report was wrong, but because someone missed a deadline, hired the wrong expert, or stopped doing the work the day after closing.

Keywords: Phase I ESA, all appropriate inquiries, CERCLA, bona fide prospective purchaser, innocent landowner, contiguous property owner, ASTM E1527, 40 C.F.R. Part 312, recognized environmental condition, environmental professional, continuing obligations, Phase II, brownfields, vapor intrusion

Phase 1 — Understand what the Phase I actually buys you

  • [ ] Internalize the liability you are trying to escape: CERCLA § 107(a), 42 U.S.C. § 9607(a), imposes strict, joint and several, and retroactive liability on the current owner or operator of a facility — with no requirement that you spilled anything, and no grandfathering for conduct that was lawful when it occurred.
  • [ ] Identify which statutory defense you are building toward: the bona fide prospective purchaser (BFPP) defense, 42 U.S.C. § 9601(40) and § 9607(r); the innocent landowner defense, § 9601(35) and § 9607(b)(3); or the contiguous property owner protection, § 9607(q).
  • [ ] Confirm that all three of those defenses share one gateway requirement: the purchaser must have conducted "all appropriate inquiries" (AAI) into prior ownership and use before acquiring the property.
  • [ ] Locate the AAI standard where it actually lives: 40 C.F.R. Part 312, EPA's AAI rule, promulgated under the Small Business Liability Relief and Brownfields Revitalization Act, Pub. L. No. 107-118 (2002).
  • [ ] Confirm which ASTM standard EPA currently recognizes as AAI-compliant. EPA's rule identifies a specific edition of ASTM E1527 as satisfying AAI, and EPA has periodically recognized new editions and sunset old ones. Do not assume; verify the operative version at 40 C.F.R. § 312.11 before you scope the work. A Phase I performed to a superseded standard is a very expensive document that buys nothing.
  • [ ] Understand the limits: AAI is a federal CERCLA concept. It does not satisfy state transfer statutes, does not cover petroleum in most respects, and is not a warranty that the property is clean.
  • [ ] Understand what AAI does not touch: common-law claims (nuisance, trespass, negligence, strict liability for abnormally dangerous activities) are STATE law and vary meaningfully from state to state. A perfect AAI record and an ironclad BFPP defense do not, by themselves, defeat a neighbor's state-law nuisance suit over a migrating plume. Likewise, land use and zoning are state and local law, and insurance coverage is state law — none of the three has a single nationwide rule, and this checklist does not supply one.
  • [ ] Note the administrative-law backdrop before you treat any EPA position as binding: courts no longer defer to an agency's interpretation of an ambiguous statute under Chevron, which the Supreme Court OVERRULED in Loper Bright Enterprises v. Raimondo, 603 U.S. 369 (2024). Reviewing courts now decide statutory meaning de novo, giving an agency's reasoning only the respect its persuasiveness earns (Skidmore v. Swift & Co., 323 U.S. 134 (1944)). Part 312 is a legislative rule adopted under an express delegation and remains the operative standard — but EPA guidance, FAQs, and enforcement-discretion memoranda are not law, and their weight is now more contestable than practitioners once assumed.

Why it matters, and the traps. Buyers reflexively call the Phase I "environmental diligence," which frames it as information-gathering. It is not. It is an affirmative-defense element, and CERCLA defenses are construed narrowly against the party invoking them. The Supreme Court's CERCLA jurisprudence — United States v. Bestfoods, 524 U.S. 51 (1998), on operator liability; Burlington Northern & Santa Fe Ry. Co. v. United States, 556 U.S. 599 (2009), on arranger liability and divisibility — makes clear how few off-ramps exist once you are in the liability net. The Phase I is one of the very few, and it is available only before you close. The trap is treating the report as a box to tick rather than as evidence you may one day hand to a district judge. For the doctrinal architecture behind all of this, work through Environmental Law: A Comprehensive Guide to CERCLA, RCRA, the Clean Air Act, and the Clean Water Act, and keep The Environmental Law Toolkit open as your map.

Our running example. Aldergate Development Partners is under contract to buy a 1.9-acre parcel on Bluestone Avenue for a mixed-use build. From roughly 1968 to 1997 the site housed Bluestone Cleaners, a commercial dry cleaner. Aldergate's principal, a seasoned multifamily developer, has never bought a former dry cleaner before. She thinks the Phase I is a two-week formality. It is, in fact, the most consequential document in her deal — and the one she is most likely to under-use.

Phase 2 — Engage a qualified "environmental professional" as defined by the rule

  • [ ] Read the regulatory definition of environmental professional (EP) at 40 C.F.R. § 312.10(b) — it is a definition, not a credential you can eyeball. It requires, in the alternative: a state PE or PG license plus three years of relevant full-time experience; a state license or certification to perform environmental inquiries plus three years; a bachelor's or higher in science or engineering plus five years; or ten years of relevant full-time experience.
  • [ ] Obtain the EP's written qualifications statement and the signed declaration required by the rule, in which the EP attests that he or she meets the definition and that the inquiry conformed to Part 312.
  • [ ] Confirm the EP's professional liability (E&O) coverage limits and whether they are adequate to your deal size — and whether the engagement letter caps liability at the fee (they almost always try).
  • [ ] Negotiate reliance: name every party who may need to rely on the report — the buyer entity, the SPE that will actually take title, the lender, any equity partner, any future assignee. Reliance letters are cheap before delivery and expensive after.
  • [ ] Confirm in writing that the consultant will perform the assessment to the currently EPA-recognized ASTM E1527 standard and in conformance with 40 C.F.R. Part 312, and that the report will say so expressly.
  • [ ] Set the scope: base Phase I, plus any non-scope items you want (asbestos, lead-based paint, radon, mold, wetlands, PFAS screening, vapor encroachment screening under ASTM E2600).

Why it matters, and the traps. The EP definition is one of the easiest places to fail the AAI rule silently. A firm may staff the site visit with a junior technician and have a licensed geologist sign the cover — that is fine, so long as the EP supervised the inquiry as the rule contemplates, but it is a fact question you do not want to litigate. The second trap is reliance. A report addressed to the seller, or to a buyer's predecessor entity, does nothing for the entity that actually takes title. Title routinely lands in a newly formed SPE that did not exist when the report was commissioned; if the SPE cannot rely on the report, the SPE — the actual owner, the actual defendant — arguably did not conduct AAI. Add the SPE by name or by defined class before the report is issued. The same discipline you would bring to a corporate diligence workstream applies here; see Conducting Merger and Acquisition Due Diligence: A Practical Checklist.

Phase 3 — The user's own responsibilities (which the consultant cannot do for you)

  • [ ] Perform (and document) the four user obligations that Part 312 places on the user, not the EP:
    • [ ] Specialized knowledge or experience, 40 C.F.R. § 312.28 — disclose what you actually know about the site or comparable sites.
    • [ ] Relationship of the purchase price to fair market value, § 312.29 — consider whether the price is below FMV because of contamination.
    • [ ] Commonly known or reasonably ascertainable information, § 312.30 — neighborhood knowledge, press coverage, local reputation.
    • [ ] The degree of obviousness of contamination and the ability to detect it, § 312.31.
  • [ ] Search for recorded environmental cleanup liens and activity and use limitations (AULs) encumbering the property, 40 C.F.R. § 312.25 — this is a user obligation you may contract to the EP or to title, but you must confirm it was done.
  • [ ] Provide the EP with everything you have: prior reports, title commitments and exceptions, surveys, leases, permits, seller disclosures, and correspondence with agencies.
  • [ ] Memorialize the user obligations in writing — a short signed User Questionnaire returned to the EP, retained in the file.

Why it matters, and the traps. This is the single most-skipped phase in American environmental diligence. Buyers assume the consultant "does the Phase I." The consultant does the consultant's half. Sections 312.28 through 312.31 are addressed to the user, and a user who knows the site was a dry cleaner, buys it for 40% of comparable land value, and then claims innocence has a serious problem no report can fix. The purchase-price factor is especially pointed: a bargain price is evidence you knew. Aldergate's principal, for instance, negotiated the Bluestone parcel to roughly two-thirds of the per-square-foot comps in the corridor, and her own email chain says why. That email is now part of the AAI record whether she likes it or not — which is exactly why the questionnaire should be completed honestly and early, not reverse-engineered later. On preserving the file that will become your evidence, see Issuing a Litigation Hold and Preserving ESI: A Practical Checklist.

Phase 4 — Records review and regulatory database search

  • [ ] Confirm the EP searched federal, tribal, state, and local government records, 40 C.F.R. § 312.26, at the search distances the ASTM standard prescribes for each database.
  • [ ] Verify coverage of the standard databases: NPL and Delisted NPL; CERCLIS/SEMS and SEMS-ARCHIVE; RCRA generators, TSD facilities, and CORRACTS; ERNS release notifications; state hazardous-waste sites; state and federal leaking underground storage tank (LUST) and UST/AST registries; institutional and engineering control registries; brownfields lists.
  • [ ] Insist on resolution of unmappable / "orphan" sites — listings the vendor could not geocode. These are not noise; the site next door is frequently in that bucket.
  • [ ] Pull local records the database vendors miss: fire department records, building department permits, health department files, the local sewer authority's industrial pretreatment records.
  • [ ] Cross-check the database output against the historical use research in Phase 5 — a 1974 dry cleaner will rarely appear in a modern regulatory database at all.

Why it matters, and the traps. The database report is the part of the Phase I that looks the most rigorous and delivers the least insight. It is a search of records that exist. Contamination from 1971 generates no record; a facility that closed before RCRA's reporting regime matured generates no record; a solvent released to a floor drain generates no record ever. Treat a clean database as the absence of a red flag, not as evidence of a clean site. The real work is Phase 5.

Phase 5 — Historical use research

  • [ ] Confirm the EP reviewed the historical sources required by 40 C.F.R. § 312.24, going back to the property's first developed use or to 1940, whichever is earlier, at intervals no greater than the standard permits.
  • [ ] Require, at minimum: historical aerial photographs, Sanborn Fire Insurance Maps, city directories, historical topographic maps, building permits, and chain-of-title / land title records.
  • [ ] Flag every historical use on the ASTM list of concern: dry cleaners, gas stations and motor-vehicle repair, metal plating and machine shops, printers, photo processing, junkyards, agricultural chemical operations, manufacturing of any kind.
  • [ ] Research adjoining and nearby properties to the same historical depth — contamination migrates, and the source is frequently upgradient rather than under your feet.
  • [ ] Insist that data gaps be identified and their significance evaluated. An unexplained twenty-year gap in the directories is a data gap; the report must say so and say whether it is significant.

Why it matters, and the traps. Historical research is where a good EP earns the fee. For Aldergate's Bluestone parcel, the 1972 Sanborn shows a rear structure labeled for "cleaning and pressing" with a solvent storage area at the alley line; the 1981 aerial shows staining and a drum rack. Nothing in the modern database shows any of it. That single Sanborn sheet is why the deal needs a Phase II — and why a consultant who quotes you a rock-bottom price and does a thin historical review is not saving you money, but rather buying you a defense that will collapse under cross-examination. The classic dry-cleaner solvent, perchloroethylene (PCE), is dense, mobile, persistent, and the leading source of vapor-intrusion problems in redevelopment; a floor drain in 1974 becomes a plume in 2026.

Phase 6 — Site reconnaissance and adjoining properties

  • [ ] Confirm the EP performed a visual inspection of the facility and of adjoining properties, 40 C.F.R. § 312.27 — physically, on foot, with photographs.
  • [ ] Walk the interior and exterior: floor drains, sumps, trenches, staining, cracked or patched slab, pits, USTs/ASTs and their vent and fill pipes, transformers and hydraulic equipment (PCBs), drums and containers, chemical storage, wells, septic systems, surface impoundments, distressed vegetation, fill material of unknown origin.
  • [ ] Document any inability to inspect — a locked tenant space, a snow-covered yard — as a data gap and evaluate whether it is significant.
  • [ ] Observe adjoining properties from the property line and the public right of way at minimum; note upgradient uses in particular.
  • [ ] Attend the site visit yourself, or send someone from the buy side. You will learn more in that ninety minutes than from the 180-page report.

Why it matters, and the traps. Site reconnaissance is one of the four components subject to the 180-day update rule (Phase 9). It is also the component most often compromised by access limitations — and access is the buyer's problem, not the consultant's. Build access rights into the purchase agreement early and broadly: right of entry for the buyer and its consultants, for both the Phase I and any Phase II, including invasive sampling, with the standard insurance and restoration covenants. If the seller will not grant sampling access, you have learned something. On negotiating access, inspection, and contingency periods, see Buying and Selling a Home: A Comprehensive Legal Guide from Contract to Closing and The Real Estate Transactions Toolkit for the transactional mechanics.

Phase 7 — Interviews with owners, occupants, and local officials

  • [ ] Confirm interviews required by 40 C.F.R. § 312.23: the current owner and occupants; the key site manager; and, for abandoned properties, one or more owners or occupants of neighboring properties.
  • [ ] Interview past owners, operators, and occupants to the extent needed to meet the objectives of AAI — for a site with a long industrial history, this is not optional.
  • [ ] Interview local government officials: fire marshal, building official, health department, environmental agency staff.
  • [ ] Get names, dates, and contemporaneous notes into the report. An interview that is not documented did not happen, as far as a court is concerned.
  • [ ] Push on the questions the seller does not want asked: prior spills, prior removals, prior notices of violation, prior agency correspondence, why the last deal fell through.

Why it matters, and the traps. Interviews are the cheapest component and the one most often reduced to a checkbox. But the retired plant manager who remembers the still bottoms being poured out behind the loading dock is worth more than every database in the report. The trap is the "no response" interview: the consultant sends one email, gets no reply, and writes "attempted." That is a data gap, and if it is a significant data gap, the report must say so.

Phase 8 — The report: RECs, HRECs, and CRECs

  • [ ] Read the report. Actually read it — not just the executive summary. Then read the findings, opinions, and conclusions, which is where the EP's professional judgment lives.
  • [ ] Understand the vocabulary, because the words are terms of art:
    • [ ] REC (Recognized Environmental Condition) — the presence or likely presence of hazardous substances or petroleum products in, on, or at the property due to a release, a likely release, or a material threat of a future release.
    • [ ] HREC (Historical REC) — a past release that has been addressed to the satisfaction of the regulatory authority with no controls required (unrestricted residential use).
    • [ ] CREC (Controlled REC) — a past release addressed to the regulator's satisfaction but with hazardous substances allowed to remain in place subject to controls (an AUL, a deed restriction, an engineering control). A CREC is still a REC.
    • [ ] de minimis conditions — not RECs, and not a basis to blow the deal.
    • [ ] Significant data gaps — must be identified, and their effect on the EP's ability to identify RECs must be evaluated.
  • [ ] Verify that the report contains the EP declaration and the qualifications statement, and that it states conformance with Part 312 and the operative ASTM standard.
  • [ ] Do not accept a report that finds "no RECs" while burying a serious data gap in an appendix. That combination is a defect, not a clean bill of health.

Why it matters, and the traps. The HREC/CREC distinction is the one lawyers most often get backwards, and it has real money in it. An HREC means the case is closed for unrestricted use. A CREC means contamination is still there, tolerated only because a control keeps people away from it — which means (a) the control is a permanent land-use constraint on your project, (b) violating the control forfeits your BFPP defense outright under § 9601(40), and (c) your redevelopment plan, which may involve excavating a slab you have just been told is an engineering control, may be the very act that breaches it. If the report shows a CREC, pull the recorded AUL and read it before you design the building. Note that the AUL itself is a creature of state law — the enabling statutes (many, but not all, states have adopted a version of the Uniform Environmental Covenants Act), the recording formalities, the enforcement rights, and the release procedure differ by jurisdiction, and there is no nationwide rule. Read the operative state statute, not a summary. When institutional controls collide with your entitlement plan — itself a matter of state and local zoning law that varies town by town — coordinate the two workstreams; see Securing Land Use Entitlements for a Development Project: A Practical Checklist and The Land Use and Development Toolkit.

Phase 9 — Timing: the 180-day and one-year shelf-life rules

  • [ ] Confirm that all AAI components were completed or updated within one year before the date of acquisition (40 C.F.R. § 312.20).
  • [ ] Confirm that these components were completed or updated within 180 days before the date of acquisition:
    • [ ] interviews with past and present owners, operators, and occupants;
    • [ ] searches for recorded environmental cleanup liens;
    • [ ] reviews of federal, tribal, state, and local government records;
    • [ ] visual inspections of the facility and of adjoining properties;
    • [ ] the declaration by the environmental professional.
  • [ ] Diary the 180-day date against the projected closing date at signing, and again whenever closing slips.
  • [ ] If closing slips past 180 days, obtain a written AAI update — not a "reliance letter," which is a different thing and does not restart the clock.
  • [ ] If a prior owner's or lender's Phase I is being reused, confirm it was performed for a user entitled to rely, and that it still fits inside both windows measured from your closing.

Why it matters, and the traps. This is where good deals go bad through pure administrative drift. A Phase I completed in March for a June closing is fine. When the closing slips to October because the seller's estate needs a probate order, and nobody re-runs the clock, the buyer has just paid for a report that is outside the 180-day window on four of its five most important components — and the AAI predicate, and therefore the BFPP defense, is gone. Aldergate's Bluestone closing slipped twice. Her counsel calendared both windows at signing and ordered a $2,800 update in week thirty-one. That $2,800 is the cheapest insurance in the deal. Treat the 180-day date the way you treat a financing contingency deadline — see Closing a Residential Real Estate Purchase: A Practical Checklist for the discipline of a closing calendar, which transfers directly to commercial deals.

Phase 10 — Deciding whether to go to Phase II

  • [ ] Understand what Phase II is: invasive sampling — soil borings, groundwater monitoring wells, soil-gas and sub-slab vapor sampling, sometimes indoor air — to test the hypotheses the Phase I generated.
  • [ ] Recognize that Phase II is NOT required by AAI. A Phase I that identifies RECs, standing alone, satisfies AAI. Phase II is about business risk, deal price, remediation cost, and your lender.
  • [ ] Go to Phase II when: the Phase I identifies a REC with real cost exposure; a CREC constrains the development plan; solvents (PCE/TCE) or petroleum are suspected and the plan involves occupied structures (vapor intrusion); the lender requires it; the state cleanup program requires it for liability protection.
  • [ ] Secure sampling access from the seller — a separate, express right, with scope, notice, insurance, restoration, and confidentiality terms.
  • [ ] Negotiate who owns the data and who must report it. Sampling can trigger reporting obligations under state law and, for certain releases, under CERCLA § 103, 42 U.S.C. § 9603. Decide before the drill rig arrives who makes that call.
  • [ ] Consider whether the state's voluntary cleanup program (VCP) or brownfields program offers a covenant not to sue or a no-further-action letter — often the most valuable thing on the table.

Why it matters, and the traps. The Phase II is where buyers discover that the law of unintended consequences is an environmental statute. Sampling creates knowledge; knowledge can create reporting duties; reporting can create a regulatory file that follows the property forever. None of that is a reason not to sample — it is a reason to sample deliberately, with counsel in the room and the reporting analysis done in advance. The opposite error is worse: deliberate ignorance. A buyer who suspects contamination and declines to look has not preserved a defense; the BFPP and innocent-landowner defenses require inquiry, not avoidance, and § 312.31's "degree of obviousness" factor is aimed precisely at the buyer who looked away. If sampling reveals a release and an agency letter follows, move immediately to Responding to a CERCLA Potentially Responsible Party Notice: A Practical Checklist.

Phase 11 — Non-scope considerations

  • [ ] Decide, in the engagement letter, which non-scope items you want assessed. The standard Phase I does not cover:
    • [ ] asbestos-containing materials (an operations-and-maintenance and OSHA/renovation issue, and a demolition budget item);
    • [ ] lead-based paint (and, in residential rentals, the federal disclosure regime);
    • [ ] radon;
    • [ ] mold and moisture;
    • [ ] lead in drinking water;
    • [ ] wetlands and Clean Water Act jurisdiction;
    • [ ] cultural and historic resources, endangered species, and regulatory compliance generally.
  • [ ] Address vapor intrusion deliberately. Vapor encroachment screening (ASTM E2600) is a distinct exercise, and for any site with a chlorinated-solvent history it is the risk that most often kills a residential redevelopment.
  • [ ] Address PFAS explicitly and carefully. EPA has moved to bring certain PFAS compounds into the CERCLA framework, and the regulatory and litigation landscape here is changing rapidly — designations, enforcement discretion policies, and legal challenges are all in motion. Do not rely on any summary, including this one, for the current status. Confirm the operative federal rule and your state's PFAS program as of your closing date.
  • [ ] Remember the petroleum exclusion: CERCLA § 101(14) generally excludes petroleum, which is why USTs are governed by RCRA Subtitle I and state UST funds — a Phase I finding of a LUST is a state-law problem that CERCLA's defenses will not solve.
  • [ ] Check for state transaction-triggered statutes. Some states impose their own pre-transfer obligations on the sale of industrial property — New Jersey's ISRA is the classic example, and other states have had or continue to have analogous transfer regimes (Connecticut's, for instance, has been legislatively restructured toward a release-based program). This is entirely state-specific. Confirm your state's rule; there is no national default.

Why it matters, and the traps. The words "non-scope" do enormous work in a Phase I report, and they are where a buyer's expectation and the consultant's obligation diverge most sharply. The buyer thinks she bought an environmental assessment; she bought a CERCLA AAI inquiry. Asbestos in the 1968 building — a real, budgeted, six-figure demolition cost on Aldergate's parcel — is nowhere in the Phase I unless someone asked for it.

Phase 12 — Allocating risk in the purchase agreement

  • [ ] Draft an environmental representation and warranty package: no releases; no USTs; compliance with environmental laws; no notices of violation; disclosure of all reports and agency correspondence; disclosure of all AULs and institutional controls.
  • [ ] Negotiate a specific environmental indemnity — separate from the general indemnity, with its own (longer or uncapped) survival period, its own basket and cap, and an express carve-out from the general survival limitation. Generic reps that die at closing are worthless against a liability that is retroactive and perpetual.
  • [ ] Consider a holdback or escrow sized to a real remediation estimate, not to a round number.
  • [ ] Price and place environmental insurance — Pollution Legal Liability (PLL) for unknown conditions, and cost-cap/stop-loss products for known remediation. Read the pollution exclusion in the CGL policy you already have; it is almost certainly absolute. Caution: insurance coverage is STATE law. Whether an "absolute" or "total" pollution exclusion reaches your loss, how the policy is construed against the drafter, what triggers coverage over a decades-long release, and how losses are allocated across successive policy periods are all questions on which states genuinely diverge — there is no national answer. Have the policy read under the law that will actually govern it.
  • [ ] If the property is coming across in an entity acquisition rather than an asset purchase, add the antitrust clearance question to the calendar. Hart-Scott-Rodino notification thresholds are adjusted annually and change every year — never rely on a remembered dollar figure; verify the currently operative threshold before you conclude a filing is not required.
  • [ ] Consider whether an environmental assessment contingency with a walk right, or a price adjustment mechanism tied to the Phase II results, is achievable.
  • [ ] Confirm the seller's covenant to cooperate post-closing with agencies, provide records, and grant access for remediation.

Why it matters, and the traps. Contractual allocation and statutory defense are not substitutes; they are layers. An indemnity is only as good as the indemnitor's balance sheet in fifteen years — and the seller of a former dry cleaner is frequently a single-asset LLC that will be dissolved the week after closing. Insurance can outlive the seller, which is why PLL exists, but PLL policies have retroactive dates, known-condition exclusions, and reporting conditions that will defeat a claim if ignored. For the drafting mechanics of indemnities, survival, baskets, and caps, see Mergers and Acquisitions: A Comprehensive Guide from Letter of Intent to Closing and The Commercial Contracts Toolkit: Drafting, Reviewing, and Enforcing Business Agreements. For the coverage analysis, see Insurance Coverage Law: A Comprehensive Guide for Policyholders and The Business Insurance and Coverage Toolkit. If the asset will be leased rather than owned, note that the BUILD Act of 2018 amended CERCLA to clarify when a tenant can hold bona fide prospective purchaser status — a point worth confirming when you review the lease, alongside Commercial Leases: A Comprehensive Guide to Negotiating and Drafting and Reviewing a Commercial Lease: A Practical Checklist.

Phase 13 — CONTINUING OBLIGATIONS after closing

This is the phase that forfeits the defense when skipped. AAI gets you to the starting line. The BFPP defense under 42 U.S.C. § 9601(40) requires you to keep satisfying its criteria for as long as you own the property.

  • [ ] Take "reasonable steps" with respect to hazardous substances at the site: stop continuing releases, prevent threatened future releases, and prevent or limit human, environmental, or natural-resource exposure to earlier releases. (Cap the exposed soil. Empty and close the sump. Secure the drums. Fence the pit.)
  • [ ] Comply with land use restrictions and do not impede the effectiveness or integrity of institutional controls — the AUL, the deed restriction, the vapor barrier, the cap.
  • [ ] Provide full cooperation, assistance, and access to persons authorized to conduct response actions or natural-resource restoration.
  • [ ] Comply with information requests and administrative subpoenas.
  • [ ] Provide all legally required notices of the discovery or release of hazardous substances (including, where applicable, CERCLA § 103, 42 U.S.C. § 9603, and state release-reporting statutes, which frequently have shorter fuses than the federal rule).
  • [ ] Ensure you are not potentially liable, and have no affiliation, with any person who is potentially liable for response costs — no familial, contractual, corporate, or financial relationship (other than the instrument of conveyance itself). Do not buy the site from a related party, and do not take back a seller note structured as an ongoing relationship without analyzing this.
  • [ ] Confirm that all disposal of hazardous substances occurred before you acquired the property.
  • [ ] Understand the windfall lien, 42 U.S.C. § 9607(r): even a valid BFPP can face a United States lien on the property up to the unrecovered response costs, to the extent the response action increased the property's fair market value.
  • [ ] Assign an owner. Put continuing obligations on a named person's job description, with a recurring calendar, an annual site walk, and a written file. Ownership changes hands; the obligation does not.

Why it matters, and the traps. Courts have not been forgiving here. In the well-known Charleston, South Carolina brownfields litigation — PCS Nitrogen, Inc. v. Ashley II of Charleston, LLC, decided by the Fourth Circuit in 2013 — a sophisticated redeveloper that had done its diligence nonetheless lost BFPP status because it failed to take reasonable steps as to conditions on the site, including failing to address sumps and debris that could serve as continuing sources. The lesson is blunt: the BFPP defense is not a certificate you earn at closing; it is a condition you maintain. A buyer who does everything right in Phases 1 through 12 and then ignores an open sump for three years has bought a very expensive report and no defense at all.

Aldergate closed on Bluestone. The Phase II confirmed PCE in shallow soil and groundwater at the rear of the parcel, and the state's voluntary cleanup program issued a covenant not to sue conditioned on a vapor barrier and a recorded AUL prohibiting groundwater use. Twenty months later, the general contractor proposed cutting three penetrations through the sub-slab vapor barrier to run new plumbing. Nobody on the construction side had ever heard the phrase "engineering control." Aldergate's counsel caught it at a routine quarterly review — the review that existed only because someone had put "continuing obligations" on a calendar. Three saw cuts would have impaired an institutional control and, on a plain reading of § 9601(40), put the entire defense at risk. That is what Phase 13 is for.

Common Mistakes to Avoid

  1. Treating the Phase I as an inspection instead of a legal defense. It is an element of an affirmative defense. Build the record accordingly.
  2. Closing on a stale report. The one-year and 180-day windows in 40 C.F.R. § 312.20 are hard. Calendar them at signing.
  3. Using a superseded ASTM standard. EPA recognizes a specific edition of E1527 and has sunset earlier ones. Verify the operative version before you scope.
  4. Skipping the user's own §§ 312.28–312.31 obligations. The consultant cannot perform these. A below-market purchase price and a knowing buyer are AAI problems no report will cure.
  5. Failing to name the title-taking entity as a reliance party. The SPE that owns the land must be the entity that conducted AAI.
  6. Confusing an HREC with a CREC. An HREC is closed. A CREC means contamination remains under a control that binds your project and, if impaired, destroys your defense.
  7. Ignoring significant data gaps. "No RECs identified" plus an unresolved data gap is a defective conclusion.
  8. Assuming the Phase I covers asbestos, lead, radon, mold, wetlands, or PFAS. It does not. Those are non-scope items you must specifically request.
  9. Not securing sampling access in the PSA. By the time you want a Phase II, the seller's leverage has peaked.
  10. Buying from an affiliate. The no-affiliation requirement in § 9601(40) is a trap for related-party and intra-family transfers, and it is unforgiving.
  11. Relying on an indemnity from a dissolving single-asset LLC. Layer insurance and escrow behind it.
  12. Doing everything right and then walking away from the continuing obligations. This is the most common way a valid defense dies.
  13. Assuming CERCLA is the whole story. Petroleum is largely excluded; state transfer acts, VCPs, cleanup programs, environmental-covenant statutes, zoning, insurance coverage, and common-law nuisance and trespass are all state regimes with their own triggers and genuine state-to-state divergence. There is no national default.
  14. Assuming a court will defer to EPA. After Loper Bright Enterprises v. Raimondo, 603 U.S. 369 (2024), Chevron is overruled and courts read the statute for themselves. A strategy premised on agency deference — or on an EPA guidance document that never went through notice and comment — is weaker than it used to be.
  15. Relying on a remembered number. Recognized ASTM editions, PFAS designations, HSR thresholds, tariff schedules, and sanctions lists all move. Verify the operative figure or list on the day you act, not from memory and not from a summary like this one.

The Consolidated Phase I / AAI Checklist

Before you engage

  • [ ] Identify the defense you are building: BFPP, innocent landowner, or contiguous property owner.
  • [ ] Verify which ASTM E1527 edition EPA currently recognizes under 40 C.F.R. § 312.11.
  • [ ] Confirm the state transfer statute / cleanup program that applies.

Engagement

  • [ ] EP meets 40 C.F.R. § 312.10(b); qualifications statement and declaration obtained.
  • [ ] Reliance extended to buyer, title-taking SPE, lender, and equity partners.
  • [ ] Scope states conformance with Part 312 and the operative ASTM standard.
  • [ ] Non-scope items (asbestos, LBP, radon, mold, wetlands, PFAS, ASTM E2600 vapor screening) elected in writing.

User obligations (non-delegable)

  • [ ] Specialized knowledge disclosed (§ 312.28).
  • [ ] Purchase price vs. FMV considered (§ 312.29).
  • [ ] Commonly known information considered (§ 312.30).
  • [ ] Obviousness / detectability considered (§ 312.31).
  • [ ] Environmental lien and AUL search completed (§ 312.25).
  • [ ] Signed User Questionnaire in the file.

The inquiry

  • [ ] Government records searched at required distances (§ 312.26).
  • [ ] Historical sources reviewed to first developed use or 1940 (§ 312.24).
  • [ ] Visual inspection of the site and adjoining properties completed (§ 312.27).
  • [ ] Interviews with owner, occupants, key site manager, past operators, local officials (§ 312.23).
  • [ ] Data gaps identified and their significance evaluated.

The report

  • [ ] Read in full; RECs, HRECs, CRECs, and de minimis conditions correctly classified.
  • [ ] EP declaration and qualifications included.
  • [ ] Recorded AULs pulled and read against the development plan.

Timing

  • [ ] All components within one year of acquisition (§ 312.20(a)).
  • [ ] Interviews, lien search, government records, visual inspection, and EP declaration within 180 days of acquisition (§ 312.20(c)).
  • [ ] Update ordered if closing slipped.

Escalation and allocation

  • [ ] Phase II decision made deliberately; sampling access and reporting strategy resolved in advance.
  • [ ] VCP / brownfields covenant explored.
  • [ ] Reps, specific environmental indemnity, survival, escrow, and PLL insurance in place.

After closing — forever

  • [ ] Reasonable steps taken and documented.
  • [ ] Institutional and engineering controls respected; construction team trained on them.
  • [ ] Full cooperation and access provided; information requests answered.
  • [ ] Required release notices given.
  • [ ] No affiliation with a liable party.
  • [ ] A named human being owns this list, with a recurring calendar.

Primary Authority

Statutes

  • Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), 42 U.S.C. §§ 9601–9675
  • 42 U.S.C. § 9607(a) — liability of current owners and operators (strict, joint and several, retroactive)
  • 42 U.S.C. § 9601(35) and § 9607(b)(3) — innocent landowner / third-party defense
  • 42 U.S.C. § 9601(35)(B) — "all appropriate inquiries"
  • 42 U.S.C. § 9601(40) and § 9607(r) — bona fide prospective purchaser; windfall lien
  • 42 U.S.C. § 9607(q) — contiguous property owner protection
  • 42 U.S.C. § 9603 — release notification requirements (CERCLA § 103)
  • 42 U.S.C. § 9601(14) — definition of hazardous substance (petroleum exclusion)
  • Small Business Liability Relief and Brownfields Revitalization Act, Pub. L. No. 107-118 (2002)
  • Brownfields Utilization, Investment, and Local Development (BUILD) Act (2018) (addressing, among other things, bona fide prospective purchaser status for tenants)
  • Resource Conservation and Recovery Act (RCRA), 42 U.S.C. §§ 6901–6992k (including Subtitle I, underground storage tanks)

Regulations

  • 40 C.F.R. Part 312 — Standards and Practices for All Appropriate Inquiries
    • § 312.10 — definitions, including "environmental professional"
    • § 312.11 — references (identifies the ASTM standard EPA recognizes as AAI-compliant; verify the current edition)
    • § 312.20 — timing / shelf life (one-year and 180-day rules)
    • § 312.21 — objectives and performance factors
    • § 312.23 — interviews with past and present owners, operators, and occupants
    • § 312.24 — reviews of historical sources of information
    • § 312.25 — searches for recorded environmental cleanup liens
    • § 312.26 — reviews of federal, tribal, state, and local government records
    • § 312.27 — visual inspections of the facility and of adjoining properties
    • § 312.28 — specialized knowledge or experience of the user
    • § 312.29 — relationship of the purchase price to the fair market value
    • § 312.30 — commonly known or reasonably ascertainable information
    • § 312.31 — degree of obviousness and ability to detect contamination

Cases

Consensus standards (not law, but incorporated by reference and relied on in practice)

  • ASTM E1527 — Standard Practice for Environmental Site Assessments: Phase I Environmental Site Assessment Process (confirm the edition EPA currently recognizes)
  • ASTM E1528 — Transaction Screen Process
  • ASTM E2247 — Phase I ESA for Forestland or Rural Property
  • ASTM E2600 — Vapor Encroachment Screening
  • ASTM E1903 — Phase II Environmental Site Assessment Process

Secondary sources

  • Powell on Real Property (environmental conditions and marketability of title)
  • EPA guidance on the "common elements" of the CERCLA landowner liability protections (addressing reasonable steps, cooperation, and institutional controls)

A currency caution — read this before relying on anything above. Environmental regulation moves, and several categories of information in any document of this kind are stale the day they are written:

  • The recognized ASTM edition. EPA recognizes a specific edition of E1527 at 40 C.F.R. § 312.11 and has sunset earlier ones. Verify the operative edition; do not rely on this or any other summary.
  • PFAS. Designations, reporting rules, enforcement-discretion policies, and the litigation challenging them are all in motion. Confirm the current federal rule and your state's program as of your closing date.
  • State transfer statutes, cleanup programs, AUL/environmental-covenant statutes, land use and zoning rules, insurance-coverage doctrine, and common-law tort claims are all STATE law. They differ materially across jurisdictions and this checklist deliberately states no nationwide rule for any of them. Confirm your state's.
  • Anything with a number attached that a federal agency adjusts periodically — HSR notification thresholds, tariff rates and duty schedules, and OFAC/BIS sanctions and entity lists — changes constantly. If your transaction touches any of them (a cross-border seller, a listed counterparty, an entity-level acquisition), treat every figure and every list as verify-before-relying and check the operative source on the day you act. Do not rely on a remembered number.
  • Deference doctrine. Chevron was overruled by Loper Bright in 2024. Arguments built on the assumption that a court will defer to EPA's reading of an ambiguous CERCLA provision are no longer sound.

Every dollar figure, every deadline, and every standard reference in this checklist should be re-verified against the operative rule on the date of your transaction.

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This checklist is general legal information from UpLaw (uplaw.us), not legal advice, and does not create an attorney-client relationship. Laws vary by state and change over time; verify current requirements and consult qualified counsel before acting.