1984年，美国农业部安装了一台双床电动自行车 Tonto Tortilla营地的氧化铝水处理系统 亚利桑那州国家森林。该系统的最初目的是减少 氟含量低于4.0 PPM，砷含量低于50 PPB。这个 来自地下水井的进水氟化物浓度约为 4.0 PPM，砷浓度约为165 PPB。这个 该项目的意义在于，它已经可靠地去除了砷和砷 从饮用水中提取氟化物18年，成功满足 新采用的砷标准为10 PPB。包括4个参考文献、图表。

In 1984, the Department of Agriculture installed a dual bed activated alumina water treatment system at the Tortilla Campgrounds in the Tonto National Forest, Arizona. The original purpose of the system was to reduce the fluoride levels to below 4.0 PPM and arsenic level to below 50 PPB. The influent fluoride concentration from the groundwater well is approximately 4.0 PPM and the arsenic concentration is approximately 165 PPB. The significance of this project is that it has reliably removed both arsenic and fluoride from potable water for eighteen years, successfully meeting the newly adopted arsenic standard of 10 PPB. Includes 4 references, figures.