Key Differences between All
Appropriate Inquiries (AAI) and ASTM E 1527-00

The EPA specified ASTM E 1527-00 for Phase I Site
Assessments as the designated "interim standards." Since then
ASTM issued the ASTM E 1527-05 which meets and surpasses the
new regulations.

The key differences between All Appropriate Inquiries standard specification and
the old ASTM E 1527-00 are
summarized in the table below.

CERCLA Background
Overview of All Appropriate Inquiries Requirements
 for Phase 1 site assessments
AAI & ASTM E 1527-00:
Key Points |
Chart of Key Differences
AAI & New ASTM E 1527-05:
Difference – Petroleum
Federal Register PDF
40 CFR Part 312 Standards
and Practices
for All Appropriate
Inquiries; Final Rule

Table 1. Key Differences between the Final All
Appropriate Inquiries Regulation Specification and the Previous
Specification Standard

Investigative Criterion AAI Specification
November 1, 2006

Previous Specification
(ASTM E1527-2000)
Definition of Environmental Professional Specific certification / license, education and experience
Interviews of current owner and tenants Mandatory. A
"reasonable attempt" had to be made.
Interviews with former owners and occupants Interviews must be conducted to achieve the objectives and
performance factors of the AAI and E-1527-05 § 312.20 (e-f)
required, but must inquire about past uses of the subject
property when interviewing current owner and occupants
Interview with neighboring or nearby property owners or
Mandatory at abandoned properties Discretionary
of Historic Sources: Period to be covered
the present to when the property first contained structures or
was used for agricultural, residential, commercial or any other
Formerly the historic investigation was to first use or 1940.
of Activity and Use Limitations (e.g., Engineering and
Institutional Controls) and Environmental Cleanup Liens
requirement as to who is responsible for the search; however,
results must be reported to the environmental professional.
was the user’s responsibility with results reported to the
environmental professional.
Scope of environmental cleanup lien search includes those
liens filed or recorded under federal, state, tribal or local
Government Records Review Records
from Federal, State, Local and Tribal sources are to be


and State records were required with local records being at the
discretion of the investigator.
inspection of subject property and nearby properties is
required; some exceptions are allowed if property cannot be
visually inspected.
specific requirement to inspect nearby properties.
Contaminants of Concern For
parties seeking CERCLA protection, the CERCLA hazardous substances
are considered.
hazardous substances and petroleum products only.
Brownsfields Grant Recipients: CERCLA hazardous substances,
petroleum and petroleum products, controlled substances.
Requires identification of sources consulted to fill data gaps
and an explanation of why there are gaps and if they are


Historic investigation was subject to the discretion of the
investigator and sources that produced no findings had to be
life of the Written Report
year with updates after 180 days.
of specified activities after 180 days.

CERCLA All Appropriate Inquiries compared to ASTM E 1527-05
Key Difference: Petroleum

The basic difference between CERCLA All Appropriate Inquiries and the
new ASTM E
1527-05 is the extent of the definition of hazardous substances. Under
the petroleum exclusion of CERCLA Section 9601(14), petroleum and crude
oil have been explicitly excluded from the definition of hazardous
substances. However, ASTM E 1527-05 includes petroleum products
because they are of concern in many commercial real estate transactions
and current custom and usage is to include an inquiry into the presence
of petroleum products in an environmental site assessment.

As noted above, the State of California now recognizes the Innocent Landowner Protection, the Contiguous Landowner Protection and the Bonafide Purchaser Protection. Thus, while CERCLA does not include petroleum products, that omission is picked up by the State of California.