Performances of the MGH filter in the trial and evaluation phase

The performance of the MGH filter during household use was evaluated in two phases after the development and standardization of the filter in the laboratory. Filters were distributed to eight households out of the 108 surveyed households in Kumarbhog village, based on

Discussion and Conclusions during March 2008, women of eight households operated the filters after getting training on the operation and maintenance of the filters. In July 2008, after three months of the trial, the performance of the filters was evaluated based on the technical validation, and their suitability and acceptability according to the users.

Technologically, the MGH filters were validated and found effective to remove As and bacterial contamination from the feed water in the trial phase. The concentrations of the treated water samples of the eight filters were tested by the field kit on a daily basis and by the ASS once a week. The As concentrations of the treated water samples of the eight filters

were below the detection limit after the first week and gradually increased to 50 µgL-1As

after one month. Results show that the concentrations of As of six treated samples were

below the limiting value of 50 µgL-1As, as set by the Bangladesh authorities. The remaining

two filters reached the breakthrough point after one month. Since the consumption of drinking water by the eight households differed, the eight filters reached the breakthrough point at different times (see Chapter 6). During the evaluation phase, five out of eight filters were still operated by the users. Chlorination was done during the filtration process. The

concentrations of As of three filters were below 50 µgL-1_{As, while two filters had exceeded}

the limiting value because the user households had not changed the spent filter materials according to the operation and maintenance instruction. It is evident that after reaching the breakthrough point of a filter, the BP solution can enhance the removal efficiency to a

certain extent. In the trial phase, all feed water samples were contaminated with FC and TC,

but most of the treated water samples were found to be bacteria-free after treating the filter with bleaching powder. During the evaluation phase, only six out of 20 treated water samples of the five filters were bacteria-free, since the users were not careful with the chlorination of the filters.

The social acceptability, appropriateness and suitability of the filters for household level use were assessed both in the trial and evaluation phase, by using as follows five evaluation criteria (slots) based on the adjusted model of Spaargaren and Van Vliet (2000): Compatibility to user household’s lifestyle (slot S1): the operation of the MGH filters was found to be compatible with the lifestyle of the eight user households. The users could operate the filter easily, given their level of education, daily life routine, and cultural, social and religious (purdah) norms. With regard to the last aspect, it could be noted that the women from the user households face problems when they have to fetch water from the deep tube wells located far away. Hence, the As removal filter fitted well within the gender division of labour in the household and the religious restrictions on women’s mobility. Domestic time or household allocation time and space structure (slot S2a): the case studies and systematic observations revealed that the women users could perform the operation of the filter within their domestic time frame. Moreover, using the filter is less time-consuming than fetching water from the far-away deep tube wells. The women indicated that they now could use the time saved to take up income-generating activities such as stitching, embroidery and other handicrafts. All user households have a one-room house, but the MGH filter is small and could be placed inside.

Affordability and resource allocation (slot S2b): the installation costs of the filter are low, because it is made from cheap local materials and chemicals that are available in local markets. Operation and maintenance costs are low. In the evaluation phase, five out of eight filters were in operation. Some women could not change the filter bed materials due to their husband’s unwillingness to buy the materials (sand and brick chips). It was reported that other male household members were not interested to help re-installing the filter either. The

Chapter Eight

severe raining and flooding in the study area was a concern as well. The users also said that they waited to re-install their filter after the rains. It is evident from the household survey that the male household heads control the household budget and expenditures and that they are the decision makers (see Chapter 7). Therefore, non-use of the three filters in the evaluation phase was not due to a lack of means. One household exchanged the spent material (sand and bricks) from the shop with new filter bed materials free of cost. The women planned to re-install their filter after the rains, if their husbands would agree to allocate the money for it.

Comfort, ease of cleaning, convenience and hygiene (slot S3): the eight women did not complain about the operation and maintenance of the filter and could easily clean the appliance. Only one woman claimed to experience difficulties with washing the filter media (sand and chips) and re-installing the filter. For this task, women preferred to get help from other members of the household, especially the men. In the evaluation phase, the filters were found to be less clean due to their unhygienic handling by the users. The users could conveniently handle and dispose of the As-contaminated sand and brick chips produced by the appliance, though not in a fully environmentally safe way. Two women spread the spent material on the cow dung stockpile (recommended by the government), one exchanged the spent material with new bricks and sand from the shop, one reused it in their construction work, and two women threw it away unsafely behind the house.

Modes of provision; operation and training (slot S4): users perceived the operation and maintenance of the filter as easy and not requiring extensive training or a follow-up for a long period. With one day of training on the installation of the filter, they performed well in operating and reinstalling it. Some women said that changing the filter materials is difficult to some extent for single women, but that it does not require any further training.