Influence of Drought and Municipal Sewage Effluents on the Baseflow Water Chemistry of an Upper Piedmont River

Abstract

The Reedy River in South Carolina is affected by the urban area of Greenville, the third most populous city in the state, and by the effluents from two large-scale municipal wastewater treatment plants (WWTPs) located on the river. Riverine water chemistry was characterized using grab samples collected annually under spring season baseflow conditions. During the 4-year time period associated with this study, climatic variations included two severe drought spring seasons (2001 and 2002), one above-normal precipitation spring season (2003), and one below-normal precipitation spring season (2004). The influence of drought and human activities on the baseflow chemistry of the river was evaluated by comparing concentrations of dissolved anions, total metals, and other important water chemistry parameters for these different years. Concentrations of copper and zinc, common non-point source contaminants related to urban activities, were not substantially elevated in the river within the urban area under baseflow conditions when compared with headwater and tributary samples. In contrast, nitrate concentrations increased from 1.2-1.6 mg/l up to 2.6-2.9 mg/l through the urban stream reach. Concentrations of other major anions (e.g., sulfate, nitrate) also increased along the reach, suggesting that the river receives continuous inputs of these species from within the urban area. The highest concentrations of major cations and anions typically were observed immediately downstream from the two WWTP effluent discharge locations. Attenuation of nitrate downstream from the WWTPs did not always track chloride changes, suggesting that nitrate concentrations were being controlled by biochemical processes in addition to physical processes. The relative trends in decreasing nitrate concentrations with downstream distance appeared to depend on drought versus non-drought conditions, with biological processes presumably serving as a more important control during non-drought spring seasons.

Extreme Hydro-Meteorological Events Influence to Water Quality of Small Rivers in Urban Area: A Case Study in Northeast Poland

“…During drought, a decrease in iron ions concentration was observed. A similar relationship occurred in the Reedy river in South Carolina, where the most visible trend within the urban area of Greenville was the dramatic decrease in total iron concentrations during dry periods 43 . Hydrological drought also effects iron decrease in www.nature.com/scientificreports www.nature.com/scientificreports/ lowland rivers 40 .…”

Release of treated effluent into streams: A global review of ecological impacts with a consideration of its potential use for environmental flows

“…Water quality in effluent‐fed streams has received the most research attention to date, including a previous review of water quality in effluent‐dominated streams (Brooks et al., 2006). Water quality changes noted include elevated temperatures (Boyle & Fraleigh, 2003; Canobbio, Mezzanotte, Sanfilippo, & Benvenuto, 2009) and nutrient levels, such as nitrate (Chen, Nam, Westerhoff, Krasner, & Amy, 2009; Hur et al., 2007), ammonium/ammonia (Boyle & Fraleigh, 2003; Gafny, Goren, & Gasith, 2000), and phosphate (Birge, Black, Short, & Westerman, 1989; Chen et al., 2009). Reaches downstream of effluent outfalls are also frequently characterised by depleted dissolved oxygen levels (Birge et al., 1989; Matamoros & Rodríguez, 2017).…”

Influences of urban wastewaters on the stream water quality: a case study from Gumushane Province, Turkey

“…The majority of reported studies have been designed around specific questions such as the effects of urbanization on spring, stream, or ground-water quality, where sampling design is carefully developed to assess those features (Al-Kharabsheh 1999;Graniel et al 1999;Vidal and Melgar 2000;Jeong 2001;AlKharabsheh and Ta'any 2003;Khazaei et al 2004;Brilly et al 2006;Rose 2007;Peters 2009;Ma et al 2009;Aitkenhead-Peterson et al 2011). Point source pollution has traditionally been the target of most water-quality studies, not only because such investigations are usually easier to design and complete, but because point source contaminants have been the predominant issue in many parts of the world (Daniel et al 2002;Keraita et al 2003;Gobeil et al 2005;Schoonover et al 2005;Lewis et al 2007;Girija et al 2007;Hur et al 2007;Shiddamallayya and Pratima 2008;Suthar et al 2010;Maani-Messai et al 2010), as well as self-purification of the streams (Heidenwag et al 2001;Vagnetti et al 2003;Cukrov et al 2008;Wei et al 2009;Vaikasas and Dumbrauskas 2010).…”