Situation Analysis on Pig Manure and Effluent Management in Vietnam

WEPA Action Programme in Vietnam
Commissioned Report

With a total population of more than 90 million, Vietnam is sustained by an economy that has grown at remarkable average 7.5 percent annually for 1992 - 2007 and 5.8 percent annually in 2008 - 2014. The agriculture sector accounts for 25 percent of GDP (2014), where livestock sub-sector's contribution to agriculture sector output is expected to rise rapidly from its current 32 percent to about 42 percent by 2020. Pig production contributes about 71 percent of the sub-sector's total. Pigs are raised all over the country and contribute nearly three-fourths of total meat production, which was estimated around more than 3,000 tons in 2011. Small-scale pig and poultry enterprises dominate livestock production, with herds of 1-5 animals in 2011 accounting for the vast majority of the nation's pig-breeding households. Livestock-keeping is especially important for poor households, as a major source of food and a means to save and accumulate capital.

Pig farming not only contributes as an important part in the economic development of Vietnam, but also creates job for farmers, as well as increases income for many households. However, fast growth of pig farming recently results in complex environmental issues due to the discharges of huge amount of untreated or improperly treated pig manure and wastewater. It is estimated that 6 million tons of CO2eq. are released annually by medium-sized pig farmers as a result of an estimated 73 million tons of pig waste, both solid and liquid, improperly disposed into ponds, channels and sewerage or merely left to decay into fields each year. Samples of wastewater taken from pig farms indicate that about 90% of them fail to meet national standards, especially in terms of Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD) levels as well as E-coli being of greatest concern.

Unfortunately, due to the lack of inventory data on livestock waste in the context of Vietnam, especially pollutant load unit from pig farms, thus it is impossible to estimate accurately the contribution of livestock (especially pig) farming, in term of percentage, to the total pollutants load discharged across the country. Currently, there is no available country-specific data on pollutant loads discharged per pig head (for different types of pig) in Vietnam (e.g. in term of SS, BOD5, COD, T-N, T-P, etc.); thus it is difficult or even impossible to give an accurate estimation of pollution loads discharge into water bodies by pig farming in Vietnam, compared with other pollution loads discharged from other sources such as domestic and industrial wastewater. Due to the different practices of pig feeding, pig cleaning among countries, hence it is expected that the pollutant load discharges per pig head are different among countries. Unless this information is available, it will be very difficult to make an accurate forecast and lead to inappropriately design of treatment systems that could not satisfy the existing effluent discharge standard.

Consequently, this study has been designed in order to fill this gap by conducting a comprehensive investigation of the existing practices and technical approaches for manure management from pig farms, either household or farm scale, through a case study in 4 selected city and provinces, including Hanoi, Hung Yen, Thai Binh and Thanh Hoa. An innovative methodology has been proposed for estimation of pollutants load unit per pig head or emission coefficients from different types of pig. Both primary and secondary data have been collected as important inputs for our estimation. An appropriate number of wastewater and manure samples have been taken, at both household and farm scale, and analysed to ensure accurate estimations of pollutant load units per different types of pig head.