Multiple coal ash spills have occurred in North Carolina, resulting in contaminated water. On February 2, 2014, the nation’s third-largest ash spill occurred in Eden (Johnson, 2015). An estimated 39,000 tons of coal ash entered the Dan River from Duke Energy’s Dan River Steam Station (“History and Response Timeline,” 2017). Coal ash is an industrial waste that contains toxic heavy metals, including arsenic, cadmium, lead, and mercury (“Coal Ash Basics,” 2019). If ingested, coal ash can lead to cancer, heart damage, lung disease, kidney disease, and other health conditions. Even when recycled or disposed of, the toxic components can dissolve from the ash into a nearby waterway, making the water harmful to drink (“Coal Ash: Hazardous to Human Health,” 2010). Even though North Carolina has ordered Duke Energy to clean up unlined coal ash deposits at six of their plants, coal ash continues to contaminate local drinking water (Page, 2019).
Pollution, from rising temperatures to toxic coal ash to hog waste, has affected North Carolina waterways in countless ways over the years. The severity of this issue was further brought to our attention when many members of the Gaston Day School community agreed that they struggled with home water quality due to coal ash and other pollutants. Thermal pollution, caused by power plants and manufacturers, leads to decreased water quality and increased mortality and migration rates of aquatic life (O’Donnel, 2018). Because of its local importance, we knew that we wanted to work on water quality. After brainstorming, a trip to the Gaston County Water Treatment Plant, and discussion with families at Gaston Day’s annual science night, our team decided to focus on the detection of pollutants in local waterways.
City Water Quality
Our team visited the Two Rivers Utilities on April 2nd, 2019. We learned about water purification and distribution processes and got a better understanding of the local measures on water purity and safety. We have discussions on the new and effective way to purify water and current issues of water treatment. We introduced our project on detecting water pollutants to the director of the water treatment plant and received positive feedback. We were inspired by their usage of fluorescence to detect E. coli in the water. With this idea, we researched the literature and found acellular fluorescent protein sensors like gTEMP to detect water pollutants without releasing living bacteria into the river.
Cadmium Detector (2012, 2014)
In 2014, our team dug deep into the Cadmium detector, which inspired by the accident of the Duke Energy. The surrounding areas of Duke Energy’s Buck Steam Station have unintentionally been affected by millions of tons of coal ash containing multiple toxic chemicals including cadmium. The release of the ash has caused the water to become hazardous with the potential to cause a wide range of health issues: flu-like symptoms, kidney damage, fragile bones, and possibly death through prolonged exposure. Along with that, heavy metal contaminants in water pose serious health problems; the lungs, liver, kidneys, blood, digestive system, and the nervous system are all affected by contamination. The Agency for Toxic Substances and Disease registry released a Priority List of Hazardous Substances (ASTDR). Heavy metals accounted for almost half of the top 10 substances. To minimize the damage caused by cadmium in water both locally and globally, our 2012 team created several heavy metal detectors, but in 2013 we decided to concentrate on the cadmium detector. The detector responds to the presence of cadmium with green fluorescence. Next, the team worked to increase the sensitivity levels of our detector. Our detector needed to be able to respond to cadmium at low enough levels that the detection would be useful and the presence of cadmium would not already be apparent. Previously, we completed the addition of the 2007 Cambridge team's sensitivity tuners to our detector. The sensitivity tuners amplify the signal received by the detector, but the detector still required specialized equipment to detect GFP.
Lithium Mining
Piedmont Lithium Limited announced that it plans on building an open-pit lithium mine that would be located in Gaston County, North Carolina (Henderson 2019). The company states that it will be blasting once a day at most (Piedmont Lithium Limited 2019). Open-pit mining has to be covered with clay, soil, and vegetation to separate the sulfides the mining uncovers from the air and water to prevent oxidation. The top layers will eventually erode but covering it will slow the process of the acid seeping into the surrounding environment. This means that the area will be permanently very acidic since there is currently no technology available to revert the effect (Encyclopedia Britannica Inc. 2019). In terms of what the company has put out, it states that there will be minimal toxic waste. The company writes that the only hazardous waste left over from the mining would be the tailings, the leftover residue from the plant, which they claim to be harmless from the test they did in their lab studies (Piedmont Lithium Limited 2019). Even though the company, states that there will be no issue with contamination of nearby water area there have been numerous similar issues in the past that had been studied that show the potentially harmful effect of mining. Mine tailings are the ore waste of mines, that are mostly toxic and need to be stored properly. Furthermore, unprotected mine tailing can potentially produce sulfuric acid if they come in contact with air and water. This will produce very acidic water, which will leach other harmful chemicals from surrounding rocks. There is not any current technology available that is able to depreciate it to be safer. (Coil et al., 2014). The company plans to dry their tailing, instead of leaving it in an impoundment. There will be a small amount of water that is released from the process as rain runoff and the excess water from the pumping. They claim that it will not have a negative effect on water in the area. (Piedmont Lithium Limited 2019). But the potential leakage of lithium into the waterways will have dire effects as lithium has been used in neurological treatments. Although lithium can be used to treat illnesses, the overuse of lithium can cause numerous nerve and muscle problems. Lithium can widely affect the flow of sodium, which affects excitation or mania, through nerve and muscle cells in the body. The overuse of lithium can cause muscle weakness, twitching, drowsiness, feeling light-headed, mood changes, blurred vision, ringing in your ears, irregular heartbeats, confusion, slurred speech, clumsiness. trouble breathing, seizures, and/or potentially death (Thornton 2019). Moreover, an article by the Journal of Neuroscience Research suggests that lithium has neuroprotective in relation to several neurodegenerative conditions including Alzheimer's disease, Huntington's disease, and amyotrophic lateral sclerosis, which results in tremors, slowness of movement and rigidity (Buck Institute for Age Research 2011). Our information was used as part of the Gaston County Water and Soil Board’s presentation over questions and concerns of safety related to the lithium mine that would be built by Piedmont Lithium Limited.
