### 1 August 8, 2011

Via Electronic Transmittal: cozzie.david@epa.gov ward.hillary@epa.gov Ms. Hillary Ward Sector Policies and Programs Division (E143-01) Office of Air Quality, Planning and Standards U.S. Environmental Protection Agency

109 T.W. Alexander Drive Research Triangle Park, NC 27709

Dear Hillary:

We appreciate your taking time on July 29, 2011 to discuss options for addr essing closed landfill areas pursuant to EPA’s revisions of 40 CFR 60 Subpart WWW (Landfill NSPS). As promised, we prepared suggestions for a gradual step down of gas system operations due to declining gas production in closed landfill areas.

The Landfill NSPS articulates design and opera tional standards for landfill gas collection and control systems (GCCS) to addr ess gradual increases in landf ill gas generation from waste placement activities. For example, the rule re quires the owner/operator of the MSW landfill to:

 Prepare a GCCS Design Plan that illustrates full build out of the GCCS;

 Install gas collection in areas of the landf ill where the age of the initial waste placed reaches the two-year or five-year milestone; and

 Expand the GCCS where operationa l standards are exceeded.

However, the Landfill NSPS requirements do not envision an analogous, step-down process for landfill areas on the downside of the gas generati on curve that are experiencing declining gas flows. The provisions offer lim ited flexibility, employ somewhat confusing definitions, and are therefore often subject to varying interpretations by regulators. For example, the MSW Landfill owner/operator may apply to:

 Remove GCCS equipment (this option only applies to the entire MSW Landfill);

 Demonstrate that non-producing areas excluded from control contri bute less than the 1% of facility NMOC emissions;

 Request a higher operating value (HOVs) fo r one or more gas collectors; or

 Decommission a gas collector (well) / seek approval for a design change such as removing the wellhead and capping the header line.

### 2 The rule does not appear to provide operational flexibility to shut-off the well, to temporarily lock out the vacuum, while de clining gas flows preclude the well from meeting the wellhead pressure, temperature and oxygen standards. With an operational shut-off, if or when gas flows increase as determined from periodic well m onitoring and surface monitoring scans, the well could be easily br ought back on-line.

We believe that this additional option or rule clarification for temporary shut-off of a well is needed because many agencies do not respond to or approve HOV or d ecommissioning requests even when sufficient documentation is provided. This appears to happen because of insufficient resources to process these requests, as well as differing interpretations of what “decommissioning” means. Absent approvals, faci lities may be forced to expand the GCCS in the closed landfill area(s) (i.e ., the default remedy in the La ndfill NSPS); such expansions typically do not correct for exceedances and in fact can make the situation worse. It can be very costly to meet NSPS operational st andards if the closed area with declining flow is expected to perform like the active landfill area with increasing gas flow.

There are also situations where a closed portion of a larger MSW landfill may have triggered the fifteen year operating timeline that is now a prer equisite for equipment removal, but the entire MSW landfill has not. Some agencies will only allow equipment removal when the entire MSW landfill, rather than a closed landfill area has triggered the fifteen year requirement. Such interpretations render the option all but useless until the entire site’s gas collection system has met the fifteen year operational timeline.

Proposed Rule Changes and Clarifications:

As we discussed on the July 29, 2011 conference ca ll, just as the Landfill NSPS has a step-up approach to collecting and controlling landfill gas, the rules need to provide for a step-down approach to operational shut-off and permanent decommissioning of portions of the collection and control system. We have id entified several potential rule clarifications and solutions to address declining gas flows and gas quality at clos ed landfills or closed landfill units or areas, which include the following:

1. Clarify that the definition of “closed landfill” re fers to an entire landfill facility that is closed, as well as to a closed landfill unit or area of an MSW Landfill. Allow closed landfill units or areas, as well as an en tire MSW Landfill to meet the NSPS rule provisions for a closed landfill. This would be consistent with how installation of controls is required by landfill area under the two- and five-year criteria prescribed in the

NSPS rule.

Further, clarify that provision for annual surface emissions monitoring (SEM) applies to closed units or areas of the MSW Landfill; wh ere results of three consecutive quarterly SEM events are less than 500 ppmv methan e allow a reduction to annual to annual testing. Currently, many agencies only allo w annual SEM where the entire facility is

closed.

### 3 2. Provide flexibility to operati onally shut-off, as well as permanently decommission gas

collection wells located in closed areas with declining flow and/or poor gas quality. Specifically, allow facility discretion to s hut-off wells and conti nue to conduct surface emissions monitoring in vicinity of the we lls in accordance with the rule. We recommend that an operational shut-off not re quire prior agency a pproval, but that the landfill should inspect and document physical condition of the well to demonstrate well integrity. We also recommend the facility maintain records of well(s) that are shut-off such as a log or GCCS plot map. This a pproach is consistent with the EPA Region V applicability determination issued to the Akron Regional Landfill, dated February 12, 2003. The Region stated that it viewed an ope rational shut-off of th e well (that keeps the well casings and heads in place) to be an opera tional change rather than a design change.

The Akron Landfill was directed to continue surface monitoring, but was relieved of conforming to the wellh ead operating standards.

Meeting the NSPS operating limits at wells w ith declining flow and poor gas quality is extremely difficult to impossible. In our experience, there is minimal risk of oxygen intrusion after placement of final cover. Further, because the ga s generation/extraction rate is significantly reduced the actual volume of oxygen entering the landfill is minimal even if the oxygen concentration of the gas it self is high. Therefor e the risk for a landfill fire is extremely low. Further, by conti nuing surface monitoring in the vicinity of the shut-off well(s), the landfill owner/operator can assure the gas collection system is still operating properly, and can iden tify if collection should re sume. Finally, operational shut-off should reduce paperwork burden for agencies and industry in obtaining HOVs

and alternative timelines to address exceedan ces of the oxygen, temperature and pressure operating limits.

3. Propose a 10% NMOC threshold for non-produci ng areas in order to address declining flows. The 10% NMOC threshold may be determined in accordance with 40 CFR § 60.754(b) as gas collection is installed in th ese areas. The non-producing area(s) would not be subject to monthly wellhead monito ring requirements or obligations to meet pressure, temperature and oxygen standards for wells located in the non-producing area(s).

To demonstrate that the 10% threshold is st ill protective of the environment, the site would continue to conduct monthly cover integrity inspections and quarterly surface emissions monitoring. If readings above 500 ppmv are not detected in non-producing area(s) after three c onsecutive quarters, then the site could defer to annual surface emissions monitoring as allowed in 40 CFR § 60.756(f). If exceedan ce(s) are detected (above 500 ppmv), then apply correctiv e actions in accordance with 40 CFR § 60.755(c)(4). The site would re-initiate qua rterly monitoring until three consecutive quarterly events demonstrate no exceedances of 500 ppmv standard. The site would then defer to annual monitoring as allowed in 40 CFR 60.756(f). This proposed provision is supplemental to the existing 1% NMOC threshold provided for in 40 CFR § 60.759(a)(3)(2) for non-producing areas where a GCCS would not be required at all.

### 4 4. Allow use of actual gas recovery data to determine when a non-productive area can meet

the 10% and 1% NMOC thresholds. Pres ently, a landfill owner/operator can only use a LFG generation model to determine when a non-productive landfill area can meet the 1% requirements for NMOC emissions, and thus be relieved of control requirements (40 CFR 60.759(a)). However, a landfill owner/opera tor may use actual site-specific LFG recovery data (measured landfill gas flow rate and NMOC concentration) to meet the criteria for complete removal of a GCCS at the end of NSPS compliance life (40 CFR 60.754(b)). We believe that actual recovery data is more accurate, and its use for evaluating the 10%NMOC threshold is warranted and consistent with the intent of the regulation.

5. Eliminate the 15-year criterion for GCCS remo val, as it is subjectiv e and has no statutory

or scientific basis. Dem onstration for GCCS removal s hould be performance based.

When the MSW Landfill can demonstrate faci lity emissions are less than 50 Mg NMOC, then the GCCS requirement of the NSPS s hould not apply. Requiring GCCS operation in

accordance with the NSPS when NMOC em issions are less than 50 Mg/year is inconsistent with the intent of the rule, and was never considered in the required financial impact analysis done for the NSPS. Neverthe less should the Agency choose to keep the 15-year criterion, we reco mmend applying it to each portion of the MSW landfill independently. For example, when one landfil l unit or area closes, the 15-year operations criterion for GCCS equipment removal starts regardless of whether other landfill units or

areas are still active.

6. Allow facilities to complete a Tier 2 or Tier 3 analysis at any time to defer NSPS criteria, as long as NSPS requirements are met to that point in time. In the NSPS rule and preamble, it is clear that EPA never intended to regulate landfills with NMOC emissions under 50 Mg/year. Therefore, whenever the MSW Landfill can demonstrate facility emissions are less than 50 Mg NMOC, then the GCCS requirement of the NSPS should not apply. It should not matter wh en the facility completes a Ti er 2 (or Tier 3) analysis. Agency applicability determinations state that “late” (after 180 days fr om the Tier 1) Tier 2 analyses could be conducted but not beyond the final compliance date under the NSPS (30 months from first exceeding 50 Mg/year). The NSPS rule is silent on this topic, and the requirement for a Tier 2 is voluntary.

### 5 Please contact us if you have any questions regarding our comments. Waste Management greatly values the successful collaboration we have shared with the Agency in developing protective and workable standa rds for MSW landfills. We look forward to our continued working relationship with you.

Sincerely,

Kerry Kelly, Director, Amy Van Kolken Banister, Senior Director, Federal Public Affairs Corporate Air Programs

CC: D. Cozzie, USEPA, OAQPS F. Caponi, LACSD S. Crawford, SWANA A. Marconi, DSWA R. Repa, NSWMA R. Strube, Veolia P. Sullivan, SCS N. Wuestenberg, Republic