... populations in and around lakes, rivers, polluted groundwater areas or oceans, and can pose major problems for humans as well. Although natural phenomena, such as volcanoes and algae blooms, can ... http://sfbay.wr.usgs.gov/access/wqdata/ QUEST MEDIA FOR TEACHING ABOUT WATER POLLUTION TOPIC BACKGROUND QUEST SUBJECTS CA SCIENCE STANDARDS WATER POLLUTION Educator Guide A resource for using ... purified and cleaned and then released into rivers, bays and the ocean. But that doesn’t eliminate the pharmaceuticals, some of which will eventually make it back into the drinking water supply....