WM of Virginia Comments to DEQs Air Guidance Memo No. ACG-016 and Waste Guidance Memo No. LPR-SW-2026-01: Early Detection and Management of Elevated Temperature Landfills dated June 8, 2026.

Section I and Throughout

Overall, please consider allowances to handle areas within landfills differently and not lump them into one ET category.

Section 1.A notes that “The generation of this gas, while a normal part of decomposition, can become out of control if a subsurface reaction results in higher temperatures in the landfill.”  For clarity and accuracy, recommend this sentence be revised to read “The generation of this gas, while a normal part of decomposition, can change considerably if a subsurface reaction results in higher temperatures in the landfill.”

Section 1.D: The use of HOV’s for categorization may create some problems with implementation and result in unintended consequences:

• As written, a single HOV approval between 150F and 170F would subject the entire site to Category 2 requirements.  This can be partly remedied by including provisions to address specific areas of the landfill differently (see comment above).  But this may also incentivize an operator to reduce flow in a high-temperature well (or wells) to avoid Category 2 classification, when the desired outcome is for the operator to remove heat and pressure from that location.
• As written, there may be gaps in applicability.  Would a facility with HOV approvals for only a range of 145F-149F not be subject to any category?
• Better approach may be to establish categories for areas of the landfill based on observed well temperatures in those areas, to better inform evaluations of future HOV requests and allow more focused implementation of remedial measures.
• Cat. 2 and 3 – only mentions AAAA HOV Demonstrations, what about XXX etc.
• Cat. 1 and 2 – What about sites with HOV’s >145f but <150f?

Section III Definitions

The definition for Elevated Temperature Landfill should be reconsidered and modified.  Typically, a portion of the landfill exhibits ET conditions.  It isn’t always the case that the entire landfill would exhibit those characteristics. Consider something more like ET event within a landfill. 

Section IV

IV.A comments:

• Monthly electronic reporting of methane, carbon dioxide, and CH4:CO2 ratio to DEQ on a monthly basis seems excessive and would result in a LOT of data for DEQ review. Recommend more focused approach that utilizes the semi-annual reports (see additional bullets below).
• A ratio below 0.9 requires notification to DEQ within 30 days.  On its own this would provide more focused notification to DEQ than the monthly data dump.  But the notification requires an evaluation of the reason for the ratio; this timing may not be sufficient to allow for a thorough evaluation of what is happening, resulting in speculation and/or evaluations that need to be revised as more data become available.
• Recommend that the semi-annual report required under 63.1981(h) be used as the reporting vehicle for ratios below 0.9.  This would be frequent enough to keep DEQ informed of the status of these wells, while still allowing for multiple months of data to be evaluated so that the reason for the ratio can be better characterized, and also assess the effectiveness of remedial measures (additional tuning, GCCS construction, etc.)

IV.B comments:

• The reference to “geysers” with no context seems unnecessary, recommend that sentence be revised to read “Potential ETLFs may exhibit increasing volumes of leachate, which can lead to leachate seeps, leachate head exceedances on the bottom liner, slope instability, leachate discharges to surface water, pressurized leachate encountered during drilling (geysers), inefficiencies in landfill gas collection systems, and increased costs to manage and dispose of leachate.”
• The frequency of recording leachate volumes is inconsistent - it first notes that volumes should be recorded at a “regular frequency (daily, weekly, monthly, or per discharge)” but then requires tracking monthly totals on a 60-month rolling basis.  Recommend revising the first sentence of IV.B.1 to read “Owners and operators of all Category 1 landfills should record leachate volumes sent to the WWTP, or other approved treatment facility, at a frequency of at least monthly.”
• Reiterating comment suggesting areas in a landfill be handled differently rather than applying all requirements sitewide.  A limited ET area may result in increased leachate volumes observed at a single sump, but that trend may not be apparent when evaluating sitewide leachate generation.
• This requirement in IV.B.3.f should be narrowed for clarity: “A listing of all WWTPs or other leachate receiving facilities that have received the landfill’s leachate along with their criteria for leachate acceptance (established thresholds for leachate constituent concentrations and leachate volumes), and an indication of whether the landfill has exceeded any of those thresholds.” Recommend limiting this listing be limited to the 60-month period being evaluated.
• IV.B.4 – these notifications will require a lot of speculation (the anticipated time it is expected to continue?).  Leachate characteristics are hard to change quickly (even with pretreatment” so the requirement to include “steps taken or planned to reduce, eliminate, and prevent reoccurrence of the circumstances resulting in an unusual condition or noncompliance” might more appropriately include a discussion of alternative disposal options.

Section V

“Black goo and Flubber” is mentioned Category 2, however this can exist without ET conditions present.

V.5. – The guidance’s perspective on leachate recirculation and the continuance of landfilling solids/residuals generated from leachate concentrations should be reevaluated.  Adding liquids back into ET conditions is not recommended but should not be further restricted in non-ET areas.

It is unclear why oxygen levels >= 2% require weekly monitoring.

See Section IV.A comment regarding monthly reporting of wellhead monitoring data to DEQ, this is better included as a summary in the semi-annual report.

Same comments on leachate sampling/notifications/recordkeeping as those listed in Section IV above.

Section VI

We support DEQ’s recommendation that wells with temps >170F be managed via alternatives in an updated GCCS Design Plan rather than through the AAAA enhanced monitoring process.

It’s unclear if DEQ intends to manage wells between 150F-170F exclusively as Category 2, with Category 3 requirements kicking in only when temps are above 170F.  If an ET area of a Facility is identified, there may be benefit in including all affected wells (some may still have temps <170) as part of the alternative operating process.  Recommend that the management of wells with H2>5% allow for management of additional wells in this manner, not just wells with temperatures >170.

Guidance sections: IV.B (p. 7–9), V.B (p. 10–11), VI.C (p. 13). However, this theme applies across the whole document.

VA program is monitoring focused with no provisions for proactive, vertical drainage-based systems or Waste Acceptance issues. The guidance repeatedly mentions proactive management, but its actual mechanisms are almost entirely monitoring and reporting, not engineered liquid drainage or waste acceptance.  The guidance as it stands is not proactive but rather appears to be reactive requiring increased monitoring and response as conditions worsen. Potential Regulatory Approach: Offer an alternative where a permittee could develop a proactive plan to facilitate drainage and avoid exothermic wastes as an alternative to the VA monitoring.  This could be done as part of permitting or via another mechanism. The carrot for the plan would be to avoid some of the monitoring and FA requirements so it could be added into the guidance as an option for development of a proactive plan involving the following elements. 

Landfill Liquids The guidance treats liquid as something to sample, not something to drain. Across Sections IV–VI, leachate appears almost exclusively as a monitoring constituent to be graphed and reported. The science of ET conditions and WM’s experience frame liquid accumulation and stagnation as a primary driver of heat accumulation. The guidance should state that maintaining free vertical drainage to the LCRS is an important preventive measure.

An increase in leachate generation rate does not necessarily indicate an ET condition, there are many other factors that could increase generation rate.  Language should be included for Category 1 landfills to evaluate and determine before having to comply with the monthly reporting and record keeping outlined in IV.B.3.  Recording and tracking should be something all are doing.

Guidance sections: IV.A (p. 6–7), V.A (p. 9–10), VI.A (p. 12), and the Category definitions.

The CH?:CO? < 0.9 wellhead trigger is not a reliable stand-alone indicator. For example, Krause et al. documented an ETLF (steel-slag alternative daily cover) that sustained elevated temperatures while CH?:CO? stayed greater than 1:1.  This is because slag carbonation consumed CO?. The ratio should be framed as one indicator within an integrated, trend-based analysis, not a standalone numeric threshold.  Overall, a better more integrated monitoring program is needed that involves parameters beyond gas to include settlement, temperature, etc., and focuses on trends.   

The H? > 5% trigger conflates an early-phase signal with a more advanced condition. The science and our experience indicate H? is an early indicator (its detection suggests methanogenic inhibition is beginning), and H? has multiple benign or non-ET sources. Thus, routing any well with H? > 5% straight into the most severe category may misclassify sites that are geochemically early or experiencing a transient condition. Recommend H? exceedances trigger investigation and trend confirmation including looking at other metrics rather than automatic top-tier classification. 

The 145°F thresholds and 15-day / 170°F windows do not recognize that normal deep-waste temperatures routinely exceed regulatory thresholds. WM field data show normal waste temperatures are typically higher than regulatory thresholds, and specifically 145°F conditions do not necessarily inhibit methanogens. The guidance should acknowledge that exceeding a wellhead temperature threshold is not itself evidence of ET conditions, and that short fixed correction windows are poorly matched to a phenomenon that develops and resolves over years but understand their intent to bring in metrics that identify conditions early and then intervene so more comprehensive metrics are needed as stated previously.

Guidance sections: I.A (p. 3, “not a landfill fire” clause), VI.A (p. 12), and Definitions.

Guidance sections: V.B.5 (p. 11, recirculation), IV.B.2 / V.B.2 (leachate constituents), IV.B / V.B (monitoring scope), and the Financial Assurance subsections.

Reconcile the leachate-recirculation prohibition with drainage. Clarify that the goal is reducing added liquid and not reducing drainage, so the two concepts are not read as contradictory.

The leachate quality monitoring portion. We have not seen good correlation with leachate monitoring and conditions higher up in the waste mass.  The Category 2 constituents (acetone, benzene, MEK, phenol, BOD:COD ratio, declining pH) are not aligned with what WM uses, especially phenol and pH.  Leachate composition is a trailing/lagging indicator so it should not serve as the primary early-warning trigger; gas and temperature trends will be way ahead. 

Financial-assurance provisions should credit proactive drainage. The FA sections load costs onto reactive monitoring and corrective action. WM notes that proactive measures would mitigate any increased closure and post closure costs so facilities that submit a proactive approach to elevated temperature mitigation would not be subject to increased FAs other than normal.