0023-6152

AA00697606

17813

査読無

0023-6152

AA00697606

Surface and groundwater quality on inorganic nitrogen (N) was monitored in the farming villages of Laivu commune, Kimthanh district, Haiduong province of northern Vietnam. In these villages, pig raising in the farm households has been enhanced since 2001, and the households feeding 10 to 150 pigs in a year amounted to 28.6% of total households of the commune. Monitoring was done at five times of a two-month interval during August 2007 and April 2008. The ammonium-N concentration was always higher than the nitrate-N concentration and showed temporal and spatial variations in both surface and groundwater. The temporal variation was rather wavy and the steady increase with time was not recognized. The spatial variation was ascribed to the difference in the intensification of pig raising among the villages. Both surface and groundwater were found to be seriously contaminated with ammonium-N in Laivu commune. The ammonium-N concentration was remarkably higher than the Vietnamese water standards for drinking purpose. Waste water and solid discharged directly from piggeries without any prevention treatment was identified as a source of N contaminating surface and groundwater. Attention should be paid to the alarmingly high level of ammonium-N in the surface and groundwater in the intensively livestock-raising as well as farming villages of the Red River Delta.