5.A - Biological Treatment of Waste: Solid Waste Disposal on Land

In category 5.A, NMVOC and PM_2.5 emissions from managed disposal in landfills are reported in accordance with review recommendation DE-5A-2017-0001. In addition to that, for the sake of completeness, PM₁₀ and TSP emissions were also reported.

In the period since 1990 (and previously, to some extent), a number of legal provisions have been issued pertaining to Germany's waste-management sector, and a number of relevant measures have been initiated. These moves have had a strong impact on trends in emissions from waste-landfilling. Relevant developments have included intensified collection of biodegradable waste from households and the commercial sector, intensified collection of other recyclable materials, such as glass, paper/cardboard, metals and plastics; separate collection of packaging and recycling of packaging. In addition, incineration of municipal waste has been expanded, and mechanical biological treatment of residual waste has been introduced. As a result, the amounts of landfilled municipal waste decreased very sharply from 1990 to 2006, and stabilised at a low level since 2006. Today over half of municipal waste produced in Germany is collected separately and gleaned for recyclable materials (separate collection of recyclable materials and biodegradable waste). National statistical data are used (see sub-chapter “activity- data”).

In 2004, about 2.000 landfills of relevance for this category were in operation in the Federal Republic of Germany.
In June 2005, in keeping with new, stricter requirements under the Ordinance on Environmentally Compatible Storage of Waste from Human Settlements (Abfallablagerungsverordnung) and the Landfill Ordinance (Deponieverordnung), nearly half of those landfills were closed. As a result, in 2017 less than 1100 landfills, divided into 5 deposition classes are still in operation.
Also, pursuant to regulations in force since June 2005, landfilling of biodegradable waste is no longer permitted - for conformance with pertinent requirements, municipal waste and other biodegradable waste must be pre-treated via thermal or mechanical-biological processes. All these measures have had strong impact on the formation of NMVOC, PM_2.5, PM₁₀ and TSP so that their emissions decreased signifficantly since 1990.

For the estimation of NMVOC, Germany decided against the proposed EF of the EMEP/EEA Guidebook 2023, but instead for the Tier1 approach of the US-EPA which is reproduced in the EMEP/EEA Guidebook 2019 (Part B, 5.A, chap. 3.2.2, p. 5) ¹⁾.

According to national experts in the field, the approach of the US-EPA is more likely to produce better data, because the ratio between NMVOC (1.3 %) and CH₄ (98.7 %) in VOC from landfill gas is scientifically sound and assumed to be the very same in Germany. Also, already existing and published data for methane emissions from landfills, derived from the IPCC-FOD Waste Model (see NIR of Germany), can be used. However, with the NIR 2023 some of the emission parameters used to estimate methane emissions have been modified (DOC for food waste, DOC_f for wood/straw, half-life time for paper and wood/straw) according to the results of research projects initiated for the improvement of the German inventory reporting (Stegmann et al, 2018; pages 172-173, table 36) ²⁾. As a result, the methane emissions have changed considerably and thus the related NMVOC-emissions that are reported here.

Emissions for PM_2.5, PM₁₀ and TSP, reported under this category, are calculated using the Tier1 approach of the EMEP/EEA Guidebook 2023, where the emission factors are 0.033, 0.219 and 0.463 [g/t] ³⁾.

The EFs are multiplied with the total amount of solid waste (AD) treated in managed above-ground landfills, following the standard equation:

EM = AD * EF

From 1990 until 2017, official statistical data provided by the Federal Statistical Office are applied ⁴⁾.

Data for 1991 and 1992 as well as 1994 and 1995 are not available and have been interpolated. From 2018 until today data are made available by the National Statistical Agency by means of a direct data provision on a yearly basis. These data comprise the total amount of solid waste deposited above-ground, meaning, that all mineral wastes (mineral/construction/demolition) are also included. Remaining fractions of these wastes (mineral/construction/demolition) go to underground landfills and therefore do not play a part in dust emissions.

The data are published on a yearly basis with an exception for the actual year of reporting. The activity data for the actual year of reporting are obtained, initially, by carrying the relevant data from the previous year forward, in unchanged form. In the following year, when the actual activity data for the given year becomes available, they replace the data that were carried forward. With regard to emissions from landfills, this procedure has only a very small impact on the total emissions in the relevant current report year.

See “Methodology”.

The AD from Statistisches Bundesamt usually have an uncertainty of ±3% whereas the uncertainties for the PMs and TSP emission factors, according to the EMEP/EEA Guidebook (Part B, 5.A, chap. 3.2.2, Table 3-1, p. 6), were estimated as:

Table 1: Uncertainty estimates of PM emission factors

Due to the fact that for the ratio of NMVOC and CH₄ in VOC from landfill gas no range is given in the EMEP-Guidebook, the overall uncertainty for the emission estimation of NMVOC is estimated by expert judgement to be ± 50%.

The waste statistics of the Federal Statistical Office are regularly published with a one-year delay - which leads to an estimation of the current reporting year. This estimate is replaced in the following year with the then current data. Since the resulting recalculation usually is very small it is not reported here.

However, in this year's reporting the correction of the deposited waste quantities is higher than usual and thus is affecting the recalculation of TSP an PMs to a higher extend than is usually the case. For this reason, the recalculation is reported here. For the sake of completeness NMVOC emissions are also reported.

Table 1: Revised 2023 NMVOC emissions, in [kt]

Table 2: Revised 2023 PM and TSP emissions, in [t]