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Spiking studies underscore the important role filtration plays in removing protozoa from surface water. As part of a pilot‐scale examination of filtration media at the Cincinnati (Ohio) Water Works, heat‐inactivated Giardia cysts and Cryptosporidium oocysts were spiked into surface water that had already undergone coagulation and sedimentation. This spiked water was then introduced into pilot‐scale filters containing sand only, typical dual anthracite–sand, and deep dual anthracite–sand media configurations. All of the media types used in this study demonstrated similar removal capabilities, with average cyst removal ranging from 2.7 to > 4.5 logs and average oocyst removal of 2.7–3.9 logs. Endospore and polystyrene bead removals were similar to those of the protozoa, but turbidity and particle counts demonstrated substantially less removal capability.

Less than half of the rural Guatemalan population has access to clean water, 98% of the country's water sources are contaminated and only 15 municipalities in the country have operational drinking water treatment systems. Guatemala also has among the world's worst health statistics for chronic malnutrition and substandard child growth attainment. Over the long term, chronic malnutrition and disease leads not only to stunted growth but also to the likelihood that children will not reach their full genetic and educational potential, thus reducing their productivity and earning power. Despite efforts to improve water systems over the past decade, improvements have not kept pace with population increases and migration. Investment in water systems has also declined because of the perceived high cost of centralized water treatment facilities. However, providing safe water does not have to be cost‐prohibitive. This article explores how the lack of safe water significantly contributes to the high incidence of diarrheal disease and chronic malnutrition and what can be done to provide clean drinking water to the Guatemalan population. Four factors, all of which can be accomplished at a relatively minor cost, are identified as key to providing clean drinking water to a household or small community.

A pilot study suggests that DAF pretreatment helps reduce membrane fouling in hollow‐fiber MF. A pilot study investigated the use of dissolved air flotation (DAF) as a pretreatment to hollow‐fiber microfiltration (MF). Results showed that DAF‐pretreated feedwater achieved longer MF runs than raw feedwater. MF performances with DAF‐pretreated water were compared for fluxes of 70, 90, 110, and 135 gfd (120, 155, 190, and 230 L/m2/h). Performance results indicated that MF run lengths of more than 30 days could be achieved at flux conditions of 70 and 90 gfd (120 and 155 L/m2/h), with run lengths of 21 and 10 days for fluxes of 110 and 135 gfd (190 and 230 L/m2/h). Experimental results from this pilot study were also interpreted using a mathematical model to determine MF backwash efficiency at the different flux conditions. Both the experimental and modeling results suggest that membrane fouling by the DAF‐pretreated water was characterized by reduced pore blockage and lower cake compressibility as compared with treatment of raw feedwater.