摘要：AbstractLusaka, Zambia, is a rapidly growing city located on a vulnerable karstic dolomite aquifer that provides most of the city's drinking water. Over 65% of residents live in peri‐urban communities with inadequate sanitation leading to widespread groundwater contamination and the spread of waterborne diseases such as cholera. To fill the water service gap, Water Trusts were created: public/private partnerships designed to provide clean water to peri‐urban community residents. Water Trusts extract groundwater via boreholes, treat it with chlorine, and distribute it to residents via public kiosks. We investigated the efficacy of drinking water provision to residents in six of Lusaka's peri‐urban communities with Water Trusts. Water samples were collected from Water Trust boreholes and kiosks, privately owned boreholes, and shallow wells during four sampling efforts. To assess potential risk to human health, water samples were analyzed forEscherichia coli(E. coli) and nitrate. Shallow wells were significantly more contaminated withE. colithan Water Trust boreholes, kiosks, and private boreholes (Tukey‐adjustedpvalues of 9.9 × 10−6). Shallow wells and private boreholes had significantly higher nitrate‐N concentrations (mean of 29.6 mg/L) than the Water Trust boreholes and kiosks (mean of 8.8 mg/L) (pvalue = 1.1 × 10−4). In 2016, a questionnaire was distributed to Water Trust managers to assess their ability to meet demands. In the six communities studied, Water Trusts served only about 60% of their residents. Water Trusts provide a much safer alternative to shallow wells with respect to nitrate andE. coli, but they struggle to keep pace with growing demand.Plain Language SummaryLusaka, Zambia, overlays a vulnerable aquifer that provides drinking water for most of the city. More than half of the city's residents live in unplanned communities with little access to clean water, trash collection, and sewage services. As a result, the groundwater is highly contaminated with bacteria and nitrates which have contributed to the spread of disease. To improve access to clean water, Water Trusts were created: community organizations that extract groundwater via boreholes, chlorinate it, and distribute it to residents at public tap stands (kiosks). We investigated water provision by Water Trusts in six unplanned communities by comparing water quality among treated, Water Trust borehole, and kiosk water and untreated water from private boreholes and shallow, hand‐dug wells. Water from these sources was analyzed forEscherichia coli(E. coli) and nitrate. Shallow wells and privately owned boreholes were generally much more contaminated withE. coliand nitrate than the Water Trust boreholes and kiosks. In addition, a survey given to Water Trust Managers revealed that only about 60% of residents were being served by Water Trusts. Overall, Water Trusts provide a safer source of water with respect to nitrates andE. coli, but they struggle to meet growing demand.Key PointsWater from private boreholes and shallow wells contains high concentrations of nitrate and, for shallow wells, alsoEscherichia coliWater Trusts provide an improved public water supply relative to other sources; however, 16% of samples from kiosks had detectableEscherichia coliNearly 40% of peri‐urban residents choose not to or cannot access Water Trust water, instead relying on private boreholes or shallow wells
