File:La Yuca Slow Sand Filter and Final Filter.jpg

From La Yuca rainwater catchment#Slow Sand: Our team chose a slow sand filter due to its ability to remove bacteria, heavy metals and small particulates. In order to construct the slow sand filter we bought a 55 gallon drum, sand and gravel. First we drilled three holes in the food-grade plastic 55 gallon drum, two on the bottom of the drum, and one on the top of the drum. Then using three male-female compression fittings, we created an entrance and exit for the water, and a valve for back flushing the slow sand filter. Back flushing is necessary due to the growth of bacteria and algae within the slow sand filter. After securing the male-female compression fittings, we filled the drum first with gravel, then with sand. The filter contains a much smaller ratio of gravel to sand. After we began filling the drum with sand. Due to the need to raise the filter 4 feet onto a bracing system, at first we only poured in a small amount of sand. We then lifted up the filter in the proper place before filling it up with the necessary amount of sand.