Wetlands in a Phase I

The subject property has low or wet ground, a pond or standing water, or the user asks whether the Phase I covers wetlands. The standard lists wetlands among its non-scope considerations (E1527-21, 13.1.5.16). How wet ground figures in the assessment depends on four things: what the user has asked for, whether the water or the ground holds or receives hazardous substances or petroleum products, whether wet ground was filled, and what risk to the planned use the user wants weighed.

What the answer turns on

What the user has asked for. No assessment of a non-scope consideration is required for all appropriate inquiries as the practice defines them, and a service beyond the practice should be agreed before the assessment begins (E1527-21, 1.4, 4.4, 13.1.2). The standard's appendixes are nonmandatory. The one on non-scope issues says wetlands are evaluated by hydrology, hydric soils and hydrophytic vegetation; that section 404 of the Clean Water Act calls for a permit before dredged or fill material is discharged into regulated wetlands; and that jurisdictional determinations and wetland permits fall mainly to the Army Corps of Engineers (E1527-21, X6.5.1).
Whether the water or the ground holds or receives hazardous substances or petroleum products. A recognized environmental condition (REC) needs hazardous substances or petroleum products present or likely present at the subject property owing to a release or likely release to the environment, or present where conditions pose a material threat of one (E1527-21, 3.2.73). The standard gives environment the federal cleanup law's meaning, which the legal background appendix sets out as including surface water, groundwater, the land surface and subsurface strata (E1527-21, 3.2.27, X1.1.1.1, footnote 21). Site visit items include standing surface water, and pools or sumps, holding liquids likely to be hazardous substances or petroleum products; pits, ponds or lagoons likely to hold such liquids or sludge, judged by signs that include discolored water, distressed vegetation or an obvious wastewater discharge; vegetation stressed by something other than lack of water; and wastewater or other liquid, stormwater included, discharged from or to the property (E1527-21, 3.2.64, 9.4.14, 9.4.22, 9.4.24, 9.4.26). Establish what drains to the wet area, and what the water and the vegetation look like.
Whether wet ground was filled. The history of uses runs back to the first developed use or 1940, whichever is earlier, and developed use includes placing fill dirt (E1527-21, 8.3.8). Fill dirt is earth brought from off site to fill or regrade land, apart from small landscaping amounts, and the site visit looks for ground graded by other than natural causes, or raised with fill of unknown origin, where it suggests debris or other waste (E1527-21, 3.2.33, 9.4.25); see fill of unknown origin. The non-scope appendix adds that buildings have sometimes gone up on illegally filled wetlands, leaving owners open to fines and to mitigation (E1527-21, X6.5.2). Establish when low ground was raised, and with what.
What risk to the planned use the user wants weighed. A business environmental risk (BER) is one that can materially affect the business tied to the current or planned use of the property, and need not be something the practice requires investigating (E1527-21, 3.2.11). The non-scope appendix says wetlands may impede or rule out planned activities such as construction or expansion, and may raise development costs (E1527-21, X6.5.2). Ecological resources and endangered species are separate non-scope considerations (E1527-21, 13.1.5.4, 13.1.5.5).

The records that bear on it

Physical setting and history. A current or historical topographic map of the U.S. Geological Survey showing the subject property is reviewed, and topographic maps reviewed for the history should be at a scale that shows hydrological features among others (E1527-21, 8.2.1, 8.3.4.4). The standard's lists of physical setting and government record sources name no wetland map (E1527-21, Table 1, Table 2, Table 3).
Site visit. A method of observation is set and documented, such as a grid for a large property, and for large undeveloped or rural tracts the user may consider the forestland and rural property practice (E1527-21, 9.2.1, Note 4). Limits set by physical obstructions such as bodies of water, and by constraints such as flooding, are noted and documented (E1527-21, 9.2.6).
Agency files. Rhode Island's file review areas include wetlands folders (Rhode Island), and Vermont's research tool covers selected watershed permits, wetlands among them (Vermont).

What the federal rule says

The inquiry rule (40 CFR part 312) does not mention wetlands. It states its objective:

The standards and practices set forth in this part for All Appropriate Inquiries are intended to result in the identification of conditions indicative of releases and threatened releases of hazardous substances on, at, in, or to the subject property.

40 CFR 312.20(e), edition revised as of July 1, 2025

How it is written up

Standing water, a pond, stressed vegetation or filled ground is a finding when the professional judges it may indicate hazardous substances or petroleum products present or likely present at the subject property, and the opinion gives the reasoning for or against each class the finding pertains to (E1527-21, 12.5, 12.6).

Where the professional concludes that hazardous substances or petroleum products are present or likely present at the subject property, in the wet area or the fill, owing to a release into the environment, the opinion gives the grounds: the water, sediment or fill, its source, and the observation or record that shows it. Unless judged a de minimis condition or a historical REC, the REC is listed in the Conclusions, and the professional should give an opinion on additional investigation, if any (E1527-21, 3.2.20, 3.2.39, 12.7, 12.8).

Where the professional concludes the wet ground raises no such question, wetlands stay a non-scope consideration (E1527-21, 13.1.2, 13.1.5.16). A wetlands service the user has engaged is reported only as the terms of engagement specify, and additions to the practice are listed (E1527-21, 12.10, 12.11). The suggested format in Appendix X5 gives it a non-scope services section, and lets BERs that go with it be discussed in the Findings, Opinions and Conclusions (E1527-21, X5.7, X5.8, X5.9).

Observation of part of the subject property cut off by standing water or flooding may be what cannot be had (E1527-21, 9.2.2, 9.2.6). Required information that good faith efforts could not obtain is a data gap, significant if it affects the ability to identify a REC: named in the Findings with the sources consulted, discussed in the Opinions and listed in the Conclusions (E1527-21, 3.2.19, 3.2.78, 12.5.1, 12.6.2, 12.7).

This page is general reference for environmental professionals. It does not classify any property. ASTM E1527-21 is the standard and is not reproduced here; the judgment of the environmental professional on the facts governs.