What is water quality?
Water is an essential component of living cells and organisms. For humans, our body consists of up to 60 percent water. The presence of certain contaminants in our water can lead to health issues, including gastrointestinal illness, reproductive problems, and neurological disorders [1]. Meanwhile, natural water systems are habitats to millions of animals and plants. Since water is so important for us, we measure certain physical, chemical, and biological characteristics of water to evaluate water quality, which reflects the suitability of water for a particular use.
Water quality measurements usually focus on [2]: |
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Bacteria are common single-celled organisms and are ubiquitous in lakes, rivers, and streams. While most of bacteria are harmless, some bacteria, for example, some kinds of Escherichia coli (abbreviated as E. coli, a rod-shaped bacteria found in the digestive tract and feces of warm-blooded animals), can cause diarrhea, urinary tract infections, respiratory illness and pneumonia, and other illnesses. The abundance of bacteria is usually determined by counting the number of bacteria colonies that grow on a prepared medium.
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What controls water quality?
The water quality of natural water can be affected by various climatic, biological, and geological processes. One example of a climatic process is a rain event. After rainfalls, the pH and conductivity of stream water decrease because normal rain has a pH of ~6 and relatively low dissolved ion concentrations. For biological processes, for example, algae produce oxygen and consume carbon dioxide and nutrients (nitrogen and phosphorous, etc.) in the water. As for geological processes, natural water can carry dissolved materials (e.g., arsenic, radon, and uranium) originating from minerals and rocks. Besides, human activities, including sewage releases, agricultural practices, manufacturing processes, and mining activities, also have significant impacts on the water we rely on. In the United States, discharges of pollutants into the waters are regulated by the Clean Water Act (CWA). Under CWA, EPA has implemented pollution control programs and developed national water quality criteria recommendations. America's drinking water is also protected by the Safe Drinking Water Act (SDWA). Under SDWA, EPA is authorized to set national health-based standards for drinking water. All health-based standards for drinking water are met consistently for >92% of the population served by community water systems [3].
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How can I find out more about water quality near me?
Water quality analyses are conducted by scientists, governmental agencies, and private groups. Some characteristics of water can be measured in the stream or at the well (e.g., temperature, pH, dissolved oxygen, conductivity, turbidity), as the photo on the right showing a United States Geological Survey (USGS) scientist taking a dissolved oxygen reading in a small stream. Sometimes, water samples need to be brought back to laboratories for more detailed analysis (e.g., analyses of individual chemicals).
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Water concerns in the NRV
Ongoing Case: the Mountain Valley Pipeline
The Mountain Valley Pipeline project is a natural gas pipeline system. It starts from northwestern West Virginia and ends at southern Virginia, spanning approximately 303 miles. The project is current under construction and is projected to be finished by the end of 2023. According to the Mountain Valley Pipeline, LLC, this project aims to "provide domestic natural gas during the winter months for the benefits of reliability and affordability in the form of lower natural gas prices for consumers" [4]. However, concerns have been raised about the impacts of this project on environment, environmental justice, climate, natural beauty and so on.
Historical Case: the Stroubles Creek
The Stroubles Creek is a freshwater stream originating from three springs in the Town of Blacksburg, Virginia. It is associated with a 14,336-acre watershed (i.e., an area of land where all surface water flows into the Stroubles Creek), which is part of the New River Watershed [5]. Stroubles Creek is in a unique place hydrologically because it is a headwater watershed, meaning all of the water within the watershed is not influenced by external runoff altering water quality or quantity. Because of its location on the Eastern Continental Divide, it drains west into the New River, which empties into the Ohio River, which empties into the Mississippi River, and finally into the Gulf of Mexico. The bordering watershed to the east drains the eastern fringes of Blacksburg and flows into the Roanoke River and eventually the Atlantic Ocean. Stroubles Creek provided an important water source for the local community. However, since the establishment of the town of Blacksburg, water quality issues in the Stroubles Creek watershed started to emerge.
References:
[1]. CDC: https://www.cdc.gov/healthywater/drinking/public/water_quality.html
[2]. USGS: https://www.usgs.gov/special-topics/water-science-school/science/water-quality-information-topic
[3]. EPA Safe Drinking Water Act: https://www.epa.gov/sdwa
[4]. Mountain Valley Pipeline: https://www.mountainvalleypipeline.info/
[5]. VWRRC Special Report: https://vtechworks.lib.vt.edu/bitstream/handle/10919/49495/VWRRC_sr201048.pdf
Figures:
[4]. Mountain Valley Pipeline: https://www.mountainvalleypipeline.info/
[6]. USGS: https://www.usgs.gov/special-topics/water-science-school/science/water-you-water-and-human-body
[7]. USGS: https://www.usgs.gov/media/images/usgs-scientist-taking-a-dissolved-oxygen-reading-a-small-stream
[8]. Liao, H., Krometis, L.-A.H., Kline, K. and Hession, W.C. (2015), Long-Term Impacts of Bacteria–Sediment Interactions in Watershed-Scale Microbial Fate and Transport Modeling. J. Environ. Qual., 44: 1483-1490. https://doi.org/10.2134/jeq2015.03.0169
[1]. CDC: https://www.cdc.gov/healthywater/drinking/public/water_quality.html
[2]. USGS: https://www.usgs.gov/special-topics/water-science-school/science/water-quality-information-topic
[3]. EPA Safe Drinking Water Act: https://www.epa.gov/sdwa
[4]. Mountain Valley Pipeline: https://www.mountainvalleypipeline.info/
[5]. VWRRC Special Report: https://vtechworks.lib.vt.edu/bitstream/handle/10919/49495/VWRRC_sr201048.pdf
Figures:
[4]. Mountain Valley Pipeline: https://www.mountainvalleypipeline.info/
[6]. USGS: https://www.usgs.gov/special-topics/water-science-school/science/water-you-water-and-human-body
[7]. USGS: https://www.usgs.gov/media/images/usgs-scientist-taking-a-dissolved-oxygen-reading-a-small-stream
[8]. Liao, H., Krometis, L.-A.H., Kline, K. and Hession, W.C. (2015), Long-Term Impacts of Bacteria–Sediment Interactions in Watershed-Scale Microbial Fate and Transport Modeling. J. Environ. Qual., 44: 1483-1490. https://doi.org/10.2134/jeq2015.03.0169