Effectiveness of public rural waterpoints in Bangladesh with special reference to arsenic mitigation

Abstract

A nationwide survey of 125,000 public rural waterpoints installed between 2007 and 2012 reveals major changes from the pre-arsenic era and expectations of the 2004 Arsenic Policy. Shallow tubewell (STW) use has greatly reduced and deep tubewells (DTWs) now dominate in arsenic-affected areas. Arsenic contamination is greatly reduced from baseline; 3.6% of DTWs, 7.6% of STWs and 5.5% of ringwells (RWs) exceed 50 μg/L. In some sub-districts contamination is worse than previously recognised. Faecal contamination affects 48% of devices, and is most severe in RWs and surface water devices (SWDs). Manganese exceeds 0.4 mg/L in 12% of DTWs, 51% of STWs and 40% of RWs. Iron exceeds 1 mg/L in 48% of devices. Sustained operation ranges from 91% in DTWs, 84% in STWs, 68% in RWs to 47–94% in SWDs. Falling water levels in shallow and deep aquifers require replacement of suction pumps. Addressing aesthetic, water quality and level issues will require major investment in piped water systems with Fe/Mn removal and chlorination. Technologies differ in household coverage (DTW > STW > RW) and use for drinking (DTW > RW > STW). With a modest increase in investment in relatively safe, popular and cost-effective DTWs and better targeting, arsenic poisoning could be virtually eliminated in 5–10 years.