Abstract |
Interest in slow sand filtration has increased dramatically in the United States in the past ten years. Research conducted to evaluate removal of Giardia cysts and bacteria, showed that slow sand filtration is very effective in removal of these contaminants. Slow sand filters are much simpler and easier to operate than plants that employ coagulation. Thus they are very well suited for treatment of previously unfiltered surface waters and would be well suited for small utilities serving from 25 to 3,000 persons. The U.S. EPA estimates that about 1,000 slow sand filters may be built as a result of proposed EPA regulations on surface water treatment. |