SEMS
SEMS is EPA's inventory of sites addressed, or needing to be addressed, under the CERCLA Superfund program. It replaced CERCLIS (40 CFR 300.5). It holds active sites and archived ones, and the regulation says inclusion is not a finding that any response is needed (40 CFR 300.5).
What puts a property on this record
SEMS tracks information on releases handled by the Superfund program, and it holds both an active site inventory and archived sites (40 CFR 300.5). The active inventory holds NPL sites, plus other sites where any of several activities (assessment, removal, remedial work, enforcement, cost recovery or oversight) is planned or under way (40 CFR 300.5).
A release can come to EPA's attention in several ways, among them a required release report, a government investigation, a permit holder's notification and a citizen petition (40 CFR 300.405(a), 300.420(b)(5)). The sections cited do not say how a discovered release comes to be entered into the inventory. The lead agency must perform a preliminary assessment of every site entered into the remedial assessment active inventory (40 CFR 300.420(b)(1)). That assessment is meant to screen out sites that are no danger to people or the environment, decide whether removal action may be needed, set priorities for site inspections, and collect existing data for later Hazard Ranking System scoring if warranted (40 CFR 300.420(b)(1)).
What a listing shows, and what it does not
The definition answers the main question: "Inclusion of a specific site or area in SEMS does not represent a determination of any party's liability, nor does it represent a finding that any response action is necessary" (40 CFR 300.5).
A site in the active inventory is either on the NPL or one where at least one of the listed activities is planned or under way. Archived sites include non-NPL sites no longer in it, and new information may return one to the active inventory (40 CFR 300.5). SEMS is described as holding information on potential as well as confirmed sites (40 CFR 300.5), so a listing does not by itself show that a site is a confirmed one.
The definition says nothing about the substances, quantities or media at a listed site, or whether anything is present at neighboring properties.
In a Phase I ESA
The standard's Table 2 has no row named for SEMS. The row for federal sites that are the subject of CERCLA removals and CERCLA orders has an approximate minimum search distance of 0.5 mile (0.8 km), and its note says the research should cover sites that are active now and sites that formerly were (E1527-21, 8.2.2, Table 2, note A). Another row covers sites with no further remedial action planned; see NFRAP / SEMS-ARCHIVE.
If the subject property or an adjoining property is listed, the standard says the agency's file on the listing should be reviewed, to help the environmental professional judge whether the listing means a recognized environmental condition, a controlled or historical one, or a de minimis condition at the subject property. If the professional skips that review, the report must say why. Other records, or interviews with regulatory officials, may stand in, with a summary and an opinion on whether they suffice (E1527-21, 8.2.3.1, 8.2.3.2).
The answer turns on the stage the site has reached and what that stage's documents say. The preliminary assessment report describes the release and its probable nature (40 CFR 300.420(b)(4)); the site inspection report covers known contaminants, pathways of migration and the human and environmental targets (40 CFR 300.420(c)(5)). For a listing at the subject property, ask whether the described release is on or comes from it. For a nearby listing, ask whether the described pathways run toward the subject property. See likely release and likely presence and adjoining or nearby property. The report states what the file shows, with the professional's opinion on which class of condition, if any, applies (see REC, CREC, HREC or de minimis condition).
For every listing of the subject property or of another site inside the search distance, the report must give the professional's judgment on what the listing means for the analysis of recognized environmental conditions at the subject property, and one statement may cover several sites (E1527-21, 8.1.10).
What the federal rule says
The rule lists, among records of the subject property that the review should include (40 CFR 312.26(b)):
CERCLIS records;
40 CFR 312.26(b)(3), edition revised as of July 1, 2025
For nearby properties the rule's list in 40 CFR 312.26(c) names CERCLIS only in "Records of former CERCLIS sites with no further remedial action notices (one-half mile)" (40 CFR 312.26(c)(2)(iii)). It lets the environmental professional modify search distances, with the rationale documented (40 CFR 312.26(d)). It provides that the standard may be used to comply with 40 CFR 312.23 through 312.31 (40 CFR 312.11(a)).
Where the record is kept
EPA publishes SEMS site data through its Superfund site search and public data downloads.
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.
Classifying a finding
Situations in which this record type bears on the answer: