Have you ever wondered how your drinking water is purified? Some people believe that their drinking water comes straight from a pipe. To the contrary, majority of the population are misinformed about how their drinking water is purified and safe for everyday consumption. Across the globe, 2 out of 10 people do not have access to safe drinking water, and in the U.S., many states face water shortages and droughts [2]. The biggest realization to make in regards to our drinking water is that our drinking water is recycled. The U.S. spends billions of dollars treating waste water to drinking water because of it being recycled through systems to preserve our fresh water resource [2]. There has been a widespread concern that dangerous chemicals have contaminated more and more of the nation’s drinking water supply [3]. The purpose of this podcast is to inform people seeking knowledge as to how their drinking water is purified.

Drinking water is purified through a number of steps according to the Carrollton Plant Water Purification Plant Representatives located in Louisiana [5] as well as Centers for Disease Control and Prevention committee in Atlanta, Georgia [4]. The first step to purifying water is coagulation [5]. Coagulant chemicals such as ferric sulfate and polyelectrolyte are added to the river water. The coagulate chemicals cause the very fine particles that make up the suspended solids present in the river to clump together or coagulate. The following step is flocculation. In this step, after the raw water is coagulated, it is gently mixed by large mechanical paddles [5]. The purpose of flocculation cause the fine, light particles that were created during coagulation process to mature into larger, denser, stable particles that will settle quickly [5]. Coagulation and Flocculation are usually a combined first step process in the beginning of the water purification process. Some states such as New York bypass those two steps and use a UV light to eliminate water-borne agents in the water [1]. The next step in the water purification process is sedimentation. During sedimentation the flocculated water travels to settling basins, and the flocculation large dense particles as mentioned previously settle to the bottom of the water supply, due to its weight [4].

The next step consists of disinfection. After the clarified water leaves the basins, chlorine and ammonia are added to the water. The chlorine disinfected water passes through a second set of basins to provide a holding/settling period for the disinfection process to become complete [5]. Once completed, step five consists of the pH levels becoming adjusted in the water. The pH levels have to be adjusted to make the water become more basic, and less corrosive for the pipes in our water distribution system for processing into consumer’s homes. After the pH levels have been adjusted, fluoridation occurs. Not many water system plants add fluoride to the water to prevent dental cavities. However, some water filtration systems do. The final step is filtration through rapid gravity filters. This is done to remove any suspended particles in the water. That concludes the processing as to how drinking water is purified. Some of the steps may be processed differently for example the Georgia plant filtrates their water before they disinfect it. However, these are the main processing steps as to how drinking water is purified. For more information, I have attached my contact information. Thank you for your time.

(This audio file was recorded Janesca Martin, undergraduate student at Penn State Brandywine, on March 15, 2016. References are in attached transcript.)

Earth Science Literacy Principles

Big Idea 5. Earth is a water planet

            5.2 Water is essential for life on Earth

            5.5 Earth’s water cycles among the reservoirs of the atmosphere, streams, lakes, ocean, glaciers, groundwater, and deep interior of the planet

            5.6 Water shapes landscapes

            5.8 Fresh water is less than 3% of the water at Earth’s surface

Big Idea 7. Humans depend on Earth for reservoirs

            7.1 Earth is our home; its resources mold civilization, drive human exploration, and inspire human endeavors that include art, literature, and science.

            7.3 Natural resources are limited

            7.5 Water resources are essential for agriculture, manufacturing, energy production, and life

Big Idea 9. Humans significantly alter the Earth

            9.4 Humans affect the quality, availability, and distribution of Earth’s water through the modification of streams, lakes, and groundwater.

            9.5 Human activities alter the natural land surface.