Million Dollar Arsenic Removal Plants in West Bengal, India: Useful or Not?

Abstract

The effectiveness of arsenic removal plants (ARPs) to provide safe water was evaluated based on a study of 577 ARPs out of 1900 installed in 5 arsenic-affected districts of West Bengal, India. Out of 577, 145 (25.1%) were found in defunct condition. Both raw and filtered water from 305 ARPs were analyzed for total arsenic concentration. Forty-eight ARPs were installed despite raw water arsenic concentrations below the Indian standard (50 µg/L) and in 22 cases even below the WHO guideline value (10 µg/L). Among the 264 ARPs having raw water arsenic above 50 µg/L, 140 (53.1%) and 73 (27.7%) failed to remove arsenic below the WHO guideline value and Indian standard, respectively. The highest arsenic concentration in treated water was 705 µg/L. Analysis of 217 treated water samples for iron showed that 175 (80.6%) failed to remove iron below 300 µg/L. The treated water became coloured on standing 6 to 8 h, for 191 (44.2%) ARPs and 25 (5.8%) produced bad-odoured water. Overall, the study showed that 475 (82.3%) of the ARPs were not useful. The reasons for ineffectiveness and poor performance of these ARPs include improper maintenance, sand gushing problems, a lack of user-friendliness and absence of community participation. A comparative study of ARPs in two different blocks (Domkol in Murshidabad district and Swarupnagar in North 24 Parganas) showed that 39 (80%) and 38 (95%) ARPs, respectively, were not useful. Further study in Gram Panchayet Kolsur, Deganga block, North 24 Parganas, showed that 14 (87.5%) ARPs were not useful. Proper watershed management with active participation from the villagers is urgently required for successful mitigation.

Groundwater arsenic contamination in Bangladesh—21 Years of research

“…We found most of the arsenic removal units from various manufacturers are technically sound. But our follow-up studies of the filters installed in many affected villages showed most of them were not functioning [47,48] due to poor maintenance and less people's participation. We have observed that these systems work if the owners regularly clean the domestic filter and back wash the ARP.…”

Arsenic removal from water/wastewater using adsorbents—A critical review

“…Arsenic removal technologies were reviewed ( [9,26,27,[34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53]576]). The major arsenic removal technologies are compared in Table 2.…”

Evaluation of the sustainability of deep groundwater as an arsenic-safe resource in the Bengal Basin

“…Household-based filters and low-arsenic dug wells require significant maintenance (1, 2), pond water is too polluted for purification by sand filters, and rainwater harvesting is seen as a solution only during monsoon (2). Treatment plants for shallow groundwater have been constructed in some areas, but a survey of 577 high-cost facilities in West Bengal, India, indicates that 82% are ineffective (3). Piped water systems that tap low-arsenic groundwater supplies are a preferred alternative, although the higher cost and maintenance effort may reduce their appeal (2).…”