**Appendix K**

**Memo: Emission Inventory for MSWLF State Plans**

January 27, 1997

[MEMORANDUM]{.underline}

SUBJECT: Emission Inventories for Existing Municipal Solid Waste (MSW)
Landfills with Design Capacities below 2.5 million Mg or 2.5 million
m^3^

FROM: Bruce C. Jordan, Director

Emission Standards Division (MD-13)

> Robert G. Kellam, Acting Director

Information Transfer and Program Integration Division (MD-12)

TO: Regional Air Directors, Regions I-X

[Introduction]{.underline}

The States are required to prepare and submit State plans for existing
MSW landfills \[landfills that have accepted waste since November 8,
1987 or have the capacity to accept future waste and are not new; i.e.,
not subject to 40 CFR Part 60, Subpart WWW, new source performance
standards (NSPS)\]. This State plan is required under 40 CFR 60,
Subparts B and Cc \[Emission Guidelines (EG\'s)\]. The plan will state
the requirements that existing MSW landfills will need to comply with to
meet the EG\'s. Also, as part of the State plan, 40 CFR 60.25 requires
the States to include "an inventory of all designated facilities,
including emissions data for the designated pollutants."
[Id.]{.underline}

In addition to the requirement for State plans, owners and operators of
MSW landfills with design capacities of less than 2.5 million Mg or 2.5
million m^3^ are required to submit a design capacity report under the
EG\'s and NSPS \[40 CFR 60.752 (a), 60.757. [See]{.underline}
[also]{.underline},

40 CFR 60.35(c)\]. However, unlike owners and operators of larger MSW
landfills who must also submit a nonmethane organic compound (NMOC)
emissions rate report and possibly install gas collection and controls,
no additional requirements apply to landfills with design capacities of
less than 2.5 million Mg or 2.5 million m^3^. As noted in the preamble
to the

final rule, "small landfills below 2.5 million Mg design capacity are
not subject to (emission) standards under section 111 because they are
not subject to controls and are not subject to emission limits," 61 FR
9905, 9912 (March 12, 1996).

[Summary]{.underline}

In view of the limited requirements of the EG and NSPS on landfill
owners and operators of MSW landfills below 2.5 million Mg or 2.5
million m^3^, the Environmental Protection Agency (EPA) will allow
States, in limited circumstances, to submit emission inventories as part
of State plans without requiring that, in all cases, that States develop
emissions data for MSW landfills below 2.5 million Mg or 2.5 million
m^3^ where development of such data would be unreasonable and
impractical. However, where accurate data are already available, or can
reasonably be generated without undue expense or effort, States should
require and include such data in their State plans. Example situations
of \"reasonable and practical\" are given below in the section,
[Requirements of State Plans: Emissions Data]{.underline}. This easing
of the NMOC emission inventory requirement, however, does not relieve
States of the obligation to provide, as part of their State plan, an
inventory of all existing MSW landfills within the State.

The EPA believes that allowing States to provide emissions data for such
MSW landfills with design capacities below 2.5 million Mg or 2.5 million
m^3^ only where accurate and reasonably available information can be
generated, is reasonable given that the applicable NSPS and the EG
simply require a design capacity report and do not require additional
emissions monitoring or controls. The EPA also believes that requiring
such information in all cases will either lead to the submission of
inaccurate, misleading and provisional information or to additional and
costly testing inconsistent with EPA's previous determination to only
require design capacity reports for such landfills. \[[See]{.underline}
[e.g]{.underline}., 61 FR 9905, 9916

(March 12, 1996), which states that \"The design capacity cutoff of 2.5
million Mg or

2.5 million cubic meters was chosen . . . to relieve as many small
businesses and municipalities as possible from the regulatory
requirements while still maintaining significant emission reduction.\"

This guidance memo does not, however, preclude States from including
emissions information from these existing MSW landfills in their State
plans and in their annual reporting of emissions to EPA if they choose
to do so. As noted previously, it also does not relieve States from the
requirement to provide an inventory of existing landfills in State
plans.

The EPA reserves the right to request emissions information under
section 114(a) of the Clean Air Act, if it determines that such
information can be obtained reasonably and practically.

[Requirements of State Plans: Emissions Data]{.underline}

In summary of the previous discussion, States need not include NMOC
emissions from MSW landfills with a design capacity below 2.5 million Mg
or 2.5 million m^3^ from the State plan emission inventory where the
estimation of these emissions is unreasonable and impractical. This
section addresses specific situations of \"unreasonable and
impractical\" and \"reasonable and practical.\"

It may be unreasonable and impractical for an MSW landfill below 2.5
million Mg or 2.5 million m^3^ to estimate NMOC emissions when a
landfill is closed and there are no records of waste in place. However,
States should require emissions data when it is reasonable and practical
to obtain the information needed to calculate NMOC emissions, for
example, when the amount of waste deposited and age of the waste can be
reasonably obtained. If waste has been recently deposited such that this
information would be reasonably expected to be available, then these
NMOC emissions should be included in the emission inventory. Also, if a
landfill has a design capacity below but close to 2.5 million Mg or 2.5
million m^3^, greater consideration should be given before a decision is
made to not require NMOC emissions in the emission inventory because the
public may have more interest in the environmental impact of the
emissions from such a landfill.

In the situation where an MSW landfill is subject to title V operating
permits because it is a major source or because of another reason
\[e.g., subject to another NSPS or national emission standard for
hazardous air pollutants (NESHAP)\], this landfill should comply with
the emission inventory requirement even if the landfill is below 2.5
million Mg or 2.5 million m^3^ in design capacity. The reason is that
emissions from title V permitted landfills must be reported under title
V and thus, it would be reasonable to include these emissions estimates
in the emission inventory for the State plan.

In addition to the requirement to report NMOC emissions in the State
plan, 40 CFR 60.25 also requires the annual reporting of emissions by
States to EPA for existing landfills whose emissions have changed more
than 5 percent from the most recently submitted emissions data. For
States with landfills with design capacities below 2.5 million Mg or 2.5
million m^3^ for which emissions data were not initially reported, this
emissions reporting requirement would not necessarily be reasonable or
practical and, thus, States are not required to meet this reporting
requirement for such landfills. However, where a State previously did
not require emissions data for a landfill close to or at the 2.5 million
Mg or 2.5 million m^3^ cutoff, and there is reason to believe emissions
may have increased by greater than 5 percent, a State may want to
reconsider whether emissions data should be required.

The allowance for exclusion of NMOC emissions from certain landfills
below 2.5 million Mg or 2.5 million m^3^ from the emission inventory
does not affect the requirement for States to submit an inventory of
existing MSW landfills with the State plans. The 40 CFR

60.25 requires such an inventory of landfills in the State plan and this
memo does not modify this requirement. It is reasonable to expect States
to know what landfills are in their geographic area and to provide this
information in their State plans.

If you have any questions on this guidance, please feel free to contact
Mary Ann Warner at (919) 541-1192.

cc: Patricia Bowlin, R-IX

Valerie Broadwell, OAQPS (MD-12)

> Ward Burns, R-VII
>
> Jeanne Cosgrove, R-I

Mick Cote, R-VI

> Renaldo Crooks, Air Resources Board, Sacramento, CA
>
> Eric Crump, OAQPS (MD-15)

John Dale, R-VIII

Scott Davis, R-IV

Christine DeRosa, R-II

> Gus Eghneim, Natural Resources Conserv. Comm., Austin, TX
>
> Allen Geswein, OSW (2306W)
>
> Michael Goo, OGC (2344)

Charles Hatten, R-V

K.C. Hustvedt, OAQPS (MD-13)

> Tom Kerr, OAP (6202J)
>
> Zofia Kosim, OECA (2242A)
>
> Scott Koschwitz, Bureau of Air Mgmt., Hartford, CT
>
> Margaret McCourtney, Min. Pollution Control Agency, St. Paul, MN

John Seitz, OAQPS (MD-10)

> Racqueline Shelton, OAQPS (MD-12)

Martha Smith, OAQPS (MD-13)

> James Topsale, R-III

Mary Ann Warner, OAQPS (MD-12)

Lydia Wegman, OAQPS (MD-10)

> Catherine Woo, R-X

OAQPS:ITPID:MWarner:JClevenger:1-1192:MD-12:1/17/97

C:\\JULIE\\WARNER\\INDF-EI