JC Weber
Professor Wagner
Geology 1305
April 9th, 2012

Victoria Water Treatment Plant Field Trip

1) What geologic formations make up the stratigraphy of the Victoria Water Treatment Plant? Consider topography, soils, and geography. (25 points) The VWTP is situated next to the Guadalupe River in Victoria, Texas. The VWTP’s location to the coast has a huge impact on the soil composition and layout of the land. This area has been subject to glacial erosion, floods, and water level increases and drops on an enormous scale. The topography of this region is that of a flood basin. It is a low lying plain with typically a 0-8% slope of the ground. The entire area is composed of alluvial stratigraphy. This means that the river and the surrounding area were shaped by the glacier movement and flooding. The soil composition is mostly sandy loam and fine clays that were deposited here after floods and water level increases. This sandy loam is layered on top of the Beaumont Formation, which is the oldest geological unit in the Victoria area. The Beaumont Formation is a predominantly clay soil type that has a very low permeability, thus forming the bottom of this area’s water table.

2) What role does the Balcones Escarpment play as a water resource in the Hill Country? What are some of the geologic structures associated with it, and what resource could it offer in the future? (20 points) The Balcones Escarpment is a line of low hills that separates the vast Great Plains from the Coastal Plains area. This separation is caused by the falling off of land by the weight of the sediment it carries due to a fault line. It is essentially a sheer separation of the landscape based on elevation. There are several faults along this area that help isolate the aquifers in the area and allow for the increased pressure that brings the water to surface in the form of springs. The hills and valleys in this location also act as a catch basin to form the recharge zone of the Edwards Aquifer. This area is also a “hot spot” for geothermal activity. Several businesses in this area have utilized the geothermal springs as part of their day to day operations. Geothermal energy can be used to control temperature in buildings and homes by running a series of heat exchange pipes in the first 10 feet of the earth. The air is moved through the building’s ductwork by a heat pump effectively heating or cooling based on the season. Geothermal energy can also be used to create electricity. The stream can be used to turn the turbines the same way they are turned now, except no fossil fuels will have to be consumed to generate the electricity.

3) Describe how the Victoria Water Treatment Plant (VWTP) maintains a reservoir (storage level) in an attempt to offset water shortages during periods of drought. (20 points) The VWTP maintains reservoir levels by pumping from the river during low usage times, processing that water and storing it for future use. They also have a total of 10 water wells that are online and functioning. Two of these are rolling wells, which means they use them to push water back to the river a supply other areas of the plant to keep the manifolds and plumbing operational. The other 8 are emergency wells. When the water levels get low enough to be in violation of the city’s Junior Permit status, the VWTP will still pull the required amount from the river, but will use these pumps to replenish the water downstream. All of this, in addition to water restrictions, ensures the city of Victoria will have water when they turn on the tap.

4) Describe the principle problems associated with water turbidity and the need to maintain water clarity. Be sure to include measures the plant takes to deal with these problems. Also explain how pH affects turbidity. What is the normal range of pH at the plant? (25 points) Water turbidity is the cloudiness of water caused by suspended particles. The primary problem associated with water turbidity is the question of what is causing the cloudiness of the water. When pulling water from the Guadalupe River, there are tens of thousands ppm of various particles in the water that are causing this cloudiness. The biggest culprit of water turbidity in our area is the fine sands that are picked up by the river on its journey to the bay. However, the filters will catch must of this sand with relative ease. Another problem is the potential for viral and bacterial growth. The more suspended particles in the water, the harder it is to sterilize via chlorine methods because the suspended particles shield the viruses and bacteria from the chlorine. The same is true for UV sterilization used in the sedimentation basins. Water’s pH is considered neutral ay 7.0. The VWTP’s pH range is between 7.8 and 8.2. The plant uses alum and chlorine to lower the pH readings and sodium hydroxide to raise them.

5) Describe two specific points that you learned at the VTP that you were unaware of prior to the field trip. Be specific. (10 points) One of the things learned from this field trip is the amount of water pulled from the Guadalupe River on a daily basis. During low water usage months, like fall and winter, the VWTP pulls around 10 mgd (million gallons per day) while during the peak summer months, it will pull and treat 20 mgd of the river water. Another lesson learned was the shear amount of chemistry involved in treating water before consumption. The chemical testing and treating, and the wide range of chemicals used, were staggering. From the alum, chlorine, and sodium hydroxide used to regulate the pH levels of the water to coagulant used to bind certain minerals in the water for ease of elimination. These tests are carried out on a 6 hour schedule every day.

Works Cited

Web Team, Texas Beyond History. "Guadalupe Bay." http://www.texasbeyondhistory.net/guadbay/setting.html. University of Texas, 03 Mar 2009. Web. 3 Apr 2012. .

Victoria, City of. "City of Victoria." http://www.victoriatx.org/publicworks/waterproduction.asp. City of Victoria, n.d. Web. 1 Apr 2012.

Eckhardt, Gregg. "Hydrology of the Edwards Aquifer." http://www.edwardsaquifer.net/geology.html. City of San Antonio, n.d. Web. 1 Apr 2012.