ESA common mistakes
ESA · Understand the traps and how to avoid them.
Treating the ASTM E1527 practice as a regulatory requirement that must be followed to the letter, and answering questions as if a Phase I is legally mandated by CERCLA.
Candidates memorize the standard's steps without learning its legal status: the AAI Rule (40 CFR Part 312) creates the legal liability protection, and ASTM E1527 is one accepted way to satisfy it, not law itself.
What to do instead
For every process question, ask 'is this statute/regulation, or is this the standard?' Keep a one-page map linking CERCLA sections, the AAI Rule, and ASTM E1527/E1528 so you can name which instrument actually imposes the obligation.
Confusing CERCLA liability defenses and protections, for example treating the BFPP, contiguous property owner, or innocent landowner defenses as interchangeable or as automatic.
The defenses share the same threshold requirements (all appropriate inquiries, no knowledge, reasonable steps, cooperation), so candidates collapse them and miss the distinct conditions each adds.
What to do instead
Build a comparison table with columns for who qualifies, the AAI requirement, reasonable steps, and continuing obligations; drill the differences until you can state what each defense adds beyond the common baseline.
Selecting a Phase I answer that includes sampling, or a Phase II answer that omits a data quality objective, because the candidate is not clear on what each phase is for.
Phase I is a non-intrusive inquiry into recognized environmental conditions (RECs); Phase II is a sampling investigation designed to confirm or delineate those conditions. Candidates under time pressure blur the boundary.
What to do instead
Anchor each phase to its output: Phase I produces REC findings and an opinion; Phase II produces data compared to screening levels. Reject any answer that assigns intrusive work to Phase I or REC identification to Phase II.
Missing the difference between a REC, a controlled REC, and a de minimis condition, and defaulting to 'REC' for every finding.
Candidates learn the REC definition but not the two carve-outs, so they over-report conditions that are controlled by existing engineering or institutional controls or that pose only a trivial threat.
What to do instead
Practice classifying findings with the three-part test: is there a release or likely release, is it controlled by a mechanism that will be maintained, and is the impact de minimis? Write the distinguishing sentence for each category and apply it to sample findings.
Skipping or underweighting historical research, such as not pursuing Sanborn maps, city directories, or aerial photographs far enough back to cover the property's full history of use.
Candidates default to the current site visit and a few database records because historical sources are time-consuming and the 'all appropriate inquiries' language feels satisfied by the standard database search.
What to do instead
Memorize the standard historical source list and the rule that research must go back to the first developed use or 1940, whichever is earlier, and that gaps must be documented and justified rather than ignored.
Designing a Phase II sampling plan without stating data quality objectives, or choosing sample locations and analytes that do not match the RECs identified in Phase I.
Candidates treat sampling as a generic checklist and do not connect the analytical suite and locations to the specific contaminants and pathways suggested by the Phase I findings.
What to do instead
For every Phase II scenario, first name the REC and the suspected contaminant, then justify the media, locations, and analyte list against it. If an answer cannot be traced back to a REC, it is likely wrong.
Misapplying screening levels, for example comparing soil concentrations to a residential standard when the site is industrial, or treating a screening level as a cleanup standard.
Candidates memorize numbers without attaching them to a land-use scenario or to the regulatory role of the value, and they conflate risk-based screening with enforceable cleanup goals.
What to do instead
Always state the exposure scenario and the regulatory status of the comparison value before answering. Practice explaining why an exceedance triggers further evaluation rather than automatic remediation.
Ignoring fate and transport mechanisms, such as assuming a dense non-aqueous phase liquid will stay where it was released or that a contaminant will not migrate off site.
Candidates focus on contaminant identity and toxicity but not on density, solubility, volatility, and subsurface geology, so they miss the migration pathway that drives the risk and liability question.
What to do instead
For each contaminant class, rehearse a short transport profile: density relative to water, solubility, volatility, and typical migration behavior. Then ask how the site geology and groundwater flow direction change the answer.
Writing or selecting report language that states conclusions without the supporting reasoning, or that omits the required user, scope, and limitations disclosures.
Candidates focus on the findings and forget that the report must document the scope, the sources reviewed, data gaps, and the rationale for each opinion, which is what makes the opinion defensible.
What to do instead
Memorize the report components as a checklist and practice writing a REC statement that includes the finding, the source, and the reasoning. Review sample answers for whether the conclusion is traceable to evidence.
Treating the Phase I as a guarantee of clean status, or advising a client that the report eliminates liability, rather than explaining the liability protections and their conditions.
Candidates confuse the deliverable with the legal outcome and do not appreciate that the protection depends on compliance with AAI, reasonable steps, and continuing obligations.
What to do instead
Frame every transactional answer around what the report supports and what the client must still do to preserve a defense. Rehearse the conditions attached to the landowner protections and the consequences of failing them.