Applying a randomized controlled trial, we study the impact of improved water transport and storage containers on the water quality and health of poor rural households. The results indicate that improved household water infrastructure improves water quality and health outcomes in an environment where point-of-source water quality is good but where recontamination is widespread, leading to unsafe point-of-use drinking water. Moreover, usage rates of 88% after 7 months are encouraging with regard to sustainable adoption. Our estimates suggest that the provision of improved household water infrastructure could ‘keep clean water clean’ at a cost of only 5% of the costs of providing households with improved public water supply. Given the general consensus in the literature that recontamination of water from improved public sources is a severe public health problem, improved transport and storage technologies appear to be an effective low-cost supplement to the current standard of financing public water supply for poor rural communities. Copyright © 2012 John Wiley & Sons, Ltd.