Fountain Hills Fountain and park
On my way to school each day in my hometown of Fountain Hills, Arizona, I pass the Fountain Hills Fountain and park. The park, built in 1970, includes 35 acres of turf and a 33-acre, million-gallon effluent lake. Effluent water is recycled wastewater, used to fill the lake and water the park. The fountain draws water from the lake and erupts up to 560 feet when all three pumps are running. During the course of a year I have observed that the area goes through cycles. At times the lake is full of animal and plant life, and other times the water is gloomy, looking as if nothing could survive. I wondered, Why does the town use effluent water in a public area? I decided to investigate.
Journal Entry: November 6, 2004, 1 p.m.
Domesticated mallards and American coots in the lake
Today I went to the park and surveyed the area. I had with me my field journal, camera, binoculars, map of the park, and traveling pack. The water was quite clear, with mallard ducks, domesticated mallards, and American coots swimming in it. No fish were observed in this lake water. I noticed that there were fewer animals on the southwestern side of the water, where most of the ducks lingered on the green grass eating "treats" thrown by visitors. All of the other areas of the lake had ducks in the water.
I returned home and began researching books and articles about the history of the lake and effluent water. In order to conserve our diminishing supply, the use of water has been reduced to 10% fresh water and 90% effluent water to irrigate turf in the state of Arizona.
Journal Entry: November 9, 2004
Today I met with the district engineer, Michael S. Thompson, and engineering technician, Robert Howes, of the Chaparral City Water Company (CCWC). It is the freshwater headquarters to both Fountain Hills and Scottsdale, Arizona. They gave me a tour of the freshwater facilities and explained the process of the water treatment. Surface water from Lake Pleasant and the Colorado River is combined with ground water from alluvial aquifers below the city of Fountain Hills. The fresh water, after treatment, is pumped into homes and commercial and industrial businesses. I now have a better understanding of the town's freshwater source, but my question is, does the use of effluent water affect the ecosystem?
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Journal Entry: November 17, 2004
Today I met with the plant operations manager, Clark Moskop, of the Fountain Hill's Sanitary District. Visitors from different countries, such as China and Germany, come to this plant to observe how to treat water. Here, I learned about the water flowing in for treatment through both gravity and pumping stations.
Pipes leading to an aeration basin
The water is treated by an aerobic, or oxygen-rich, procedure in which chemicals such as magnesium hydroxide [Mg(OH)2], which neutralizes acids; chlorine (Cl), for disinfection; and polymers, substances consisting of giant molecules that help the solids stay together, are used. As I walked through the plant, I heard loud clanking sounds coming from the main processor, or screen, through which the "raw" effluent water flows. It removes foreign objects from the water and disposes of them. From the screen, I followed a pipe that extended to an aeration basin underneath the ground. Here, microorganisms such as stalked ciliates consume the organic matter. This mixture of microorganisms and raw effluent is known as "mixed liquor."
Schematic drawing of water treatment process (Click to enlarge)
I wondered how the microorganisms could stay alive in this sealed environment. A pipe pumps oxygenated air into the basin where the microorganisms absorb organic matter through their cell membranes and digest it to carry on their life process. Looking into the basin, I saw the brown tint of the sludge washing up the concrete walls, extending into the darkness.
Disinfection tanks
After the aeration basin is a secondary clarifier, or settling tank, where the microorganisms settle out. The microorganisms, now referred to as "sludge," are recycled to the aeration basin to maintain the process. Mr. Moskop then led me to a large, spacious building containing blue cylinders, about six feet long, that were making a faint swishing noise. The liquids from the clarifier are transported here for disinfection and final discharge.
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