Coal Combustion Residuals Units

Coal combustion residuals (CCR) are fly ash, bottom ash, boiler slag and flue gas desulfurization materials from burning coal to generate electricity at electric utilities and independent power producers (40 CFR 257.53). Subpart D of 40 CFR part 257 sets national criteria for the landfills and surface impoundments that hold them, and has the owner or operator of each CCR unit keep an operating record, notify the State Director or Tribal authority, and post its compliance documents on a public website (40 CFR 257.105, 257.106, 257.107). The standard's table of standard sources does not name these records (E1527-21, 8.2.2, Table 2).

What puts a property on this record

The subpart applies to owners and operators of new and existing CCR landfills and surface impoundments that dispose of or otherwise manage CCR from electric utilities and independent power producers, off the plant's site too unless the subpart provides otherwise. It also reaches inactive impoundments at active facilities, and legacy impoundments at plants that stopped generating before October 19, 2015 (40 CFR 257.50(b), (c), (e)).

A CCR surface impoundment is a natural depression, excavation or diked area designed to hold an accumulation of CCR and liquids, in which the unit treats, stores or disposes of CCR. A CCR landfill is an area of land or an excavation containing CCR that is not an impoundment or another place the definition excludes; it includes sand and gravel pits and quarries that receive CCR, CCR piles, and any practice that is not a beneficial use (40 CFR 257.53). The subpart also covers CCR management units, other areas where noncontainerized CCR is received, placed or managed, inactive landfills and units closed before October 19, 2015 among them, in the amounts and places it sets and with exceptions (40 CFR 257.50(d), 257.53).

The subpart does not apply to these materials from facilities that are not part of an electric utility or independent power producer, such as manufacturing plants, universities and hospitals; to residuals from fuels other than coal, unless more than half the fuel is coal; to beneficial use; to CCR placed at coal mines; or to municipal solid waste landfills that receive CCR (40 CFR 257.50(f) to (i)).

What the owner must post. The owner or operator keeps a public website titled "CCR Rule Compliance Data and Information", open to anyone without registration or a document request (40 CFR 257.107(a)). Documents go up within 30 days of being placed in the operating record, and stay at least five years from posting unless the section sets another period (40 CFR 257.107(c), (d)). They include inspection reports, the annual groundwater monitoring and corrective action report, notice that appendix IV constituents were detected at statistically significant levels above the groundwater protection standard with the notices to land owners, the corrective measures assessment, the closure and post-closure plans, notices of closure, and notice that a deed notation was recorded (40 CFR 257.107(f) to (i)).

What a listing shows, and what it does not

The regulation does not say which units are on any list. The operating record, like the website, keeps a file at least five years unless the subpart specifies otherwise, so an older document may be gone from both (40 CFR 257.105(b), 257.107(c)).

After closure, the owner or operator records a notation on the deed, or another instrument normally examined during title search, telling any potential purchaser that the land was used as a CCR unit and that its use is restricted under the post-closure care requirements; a unit closed by completing all removal and decontamination, groundwater corrective action included, during its active life is exempt (40 CFR 257.102(c)(1), (i)(4)). Post-closure care, which such a unit does not owe, maintains the final cover and the groundwater monitoring system, among other things (40 CFR 257.104(a), (b)). It runs 30 years, and continues past that while the unit remains in assessment monitoring; a unit whose removal was finished during its active life except for groundwater corrective action must complete that corrective action in the post-closure care period (40 CFR 257.102(c)(2), 257.104(c)). Where appendix IV constituents are found at statistically significant levels above the groundwater protection standard and sampling shows contaminants have migrated off-site, the owner or operator must notify all who own or live on land over any part of the plume (40 CFR 257.95(g)(2)).

In a Phase I ESA

Table 3, the standard's examples of additional records, does not name these records (E1527-21, Table 3). Additional records are checked when the environmental professional judges them reasonably ascertainable, useful, accurate and complete enough for the purpose of the records review, and generally obtained in local practice for the kind of transaction. Where one supplements a record type the standard lists, its search distance should be no less than that type's, as adjusted under the standard (E1527-21, 8.2.4). The standard does not say whether a list of CCR units supplements its state and tribal landfill lists, with their 0.5 mile distance (E1527-21, Table 2); see landfills and solid waste. Pits, ponds or lagoons are site visit features, as are areas that appear graded by other than natural causes or built up with fill whose origin is unknown, and mounds or depressions, where they suggest solid waste disposal (E1527-21, 9.4.22, 9.4.25).

For a unit on the subject property, the answer turns on how it was closed, whether the cover and monitoring systems are intact, what the groundwater reports show, and whether a deed notation is recorded. Land title records are where the standard says activity and use limitations and environmental liens can ordinarily be found, and it makes their review a user responsibility (E1527-21, 5.4, 6.2); if a notation is found, the standard's definition is the test of whether it is an activity and use limitation (E1527-21, 3.2.2); see activity and use limitations. For a known release at a unit nearby, the standard's nonmandatory appendix X4 weighs whether it likely reached the subject property by where the source lies, the topography, geology and hydrogeology, and other information the assessment gathers (E1527-21, X4.1). Look for the subject property among the notices to land owners on the unit's website, and ask whether its owner has received one (40 CFR 257.95(g)(2), 257.107(h)(6)). See landfill within the search distance.

If the professional concludes that hazardous substances or petroleum products are present or likely present at the subject property because of a release or a likely one, or present under conditions posing a material threat of a future release, then 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, 3.2.73, 12.7, 12.8).

A listing of the subject property, or of another site inside the approximate minimum search distance, from any source the assessment uses gets the professional's judgment on its significance (E1527-21, 8.1.10).

What the federal rule says

The inquiry rule (40 CFR part 312) does not mention coal ash. For nearby properties it lists:

Records of federally-permitted, tribal-permitted, or state-permitted (or registered) landfills and solid waste management facilities (one-half mile)

40 CFR 312.26(c)(3)(ii), edition revised as of July 1, 2025

For the subject property, the review should include "landfill and other disposal unit location records and permits" (40 CFR 312.26(b)(2)). The rule does not say whether a CCR unit's records are among them. It lets the procedures of E1527-21 be used to comply with its sections 312.23 through 312.31 (40 CFR 312.11(a)).

Where the record is kept

Each owner or operator keeps a dated operating record at the facility (40 CFR 257.105(a)). The State Director or Tribal authority may ask for any document the subpart requires that the website does not carry (40 CFR 257.105(d)). A Participating State, one whose CCR program is approved under RCRA section 4005(d), has a state agency that operates the CCR permit program (40 CFR 257.53). Some demonstrations the subpart requires are certified by a qualified professional engineer, or approved by that agency or by EPA where EPA is the permitting authority (40 CFR 257.60(b)).

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.