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page 76 of 142 RIVM report 773301 001 / NRP report 410200 051
were estimated from country-specific values for septic tanks, latrines, open sewers and wastewater
treatment in urban and rural areas following the methodology and assumptions of Doorn HWDO (1997).
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In addition, several national greenhouse gas inventories reports mention a methane recovery rate of
about 75% for their with wastewater treatment plants (WWTPs). Therefore we tentatively assumed a
75% methane recovery for all WWTPs, which amounts to a global total of about 0.6 Tg. The
resulting emissions of the new category are presented in Fig. 4.8. According to this dataset, the
emissions from waste water treatment and disposal increased from 19 to 33 Tg in the period 1970-
1995, with 85% stemming from waste water disposal, i.e. from latrines, septic tanks and open sewers.
This leads to the conclusion that landfills and domestic and industrial wastewater disposal (latrines,
septic tanks, open sewers, and WWTPs) appear to contribute about the same to global methane
emissions.
For domestic waste burning (i.e. by households for non-energetic purposes, just to get rid of the
refuse) we tentatively assumed that about 10 kg waste per urban capita is burned per year E\ XUEDQ
KRXVHKROGVin less developed countries. This values has been adopted from Gupta HWDO (1998) who
use the assumption that in India about 10 kg/cap is burnt per urban household per year. This is about
5% of total waste generation per household in India. In rural areas of LDC we assume no
uncontrolled burning in addition to the agricultural residue burning and biofuel use that is already
accounted for in another source category (either all domestic waste is assumed to be dumped or the
amount burnt for non-energy purposes is neglected). In contrast, for industrialised countries, we
assume that domestic waste burning only occurs in rural areas, where waste incineration regulation is
less well controlled. Based on NMVOC data for the USA (Nizich and Pope, 1998) we estimate the
amount burned at 250 kg/cap per year for households LQUXUDODUHDV of OECD'90 countries, except in
Western European countries and Japan, where we assume that this amount is much lower. For these
countries, as well as for EIT countries, we tentatively assume a burning rate of 25 kg/cap for rural
households per year.