Humphrey Charles, Finley Algernon, O'Driscoll Michael, Manda Alex, Iverson Guy
Environmental Health Sciences Program, East Carolina University, 3408 Carol Belk Building, Greenville, NC 27858, USA E-mail:
Environmental Health Sciences Program, East Carolina University, 3400 Carol Belk Building Greenville, NC 27858, USA.
Water Sci Technol. 2015;72(10):1851-60. doi: 10.2166/wst.2015.411.
The goal of this study was to determine if onsite wastewater treatment systems (OWS) were influencing groundwater and surface water Escherichia coli concentrations in a coastal plain watershed. Piezometers for groundwater monitoring were installed at four residences served by OWS and five residences served by a municipal wastewater treatment system (MWS). The residences were located in two different, but nearby (<3 km), watersheds. Effluent from the four septic tanks, groundwater from piezometers, and the streams draining the OWS and MWS watersheds were sampled on five dates between September 2011 and May 2012. Groundwater E. coli concentrations and specific conductivity were elevated within the flow path of the OWS and near the stream, relative to other groundwater sampling locations in the two watersheds. Groundwater discharge in the OWS watershed could be a contributor of E. coli to the stream because E. coli concentrations in groundwater at the stream bank and in the stream were similar. Stream E. coli concentrations were higher for the OWS in relation to MWS watersheds on each sampling date. Water quality could be improved by ensuring OWS are installed and operated to maintain adequate separation distances to water resources.
本研究的目的是确定现场污水处理系统（OWS）是否会影响沿海平原流域的地下水和地表水大肠杆菌浓度。在由OWS服务的四处住宅以及由市政污水处理系统（MWS）服务的五处住宅安装了用于地下水监测的测压管。这些住宅位于两个不同但相邻（<3公里）的流域。在2011年9月至2012年5月期间的五个日期，对四个化粪池的出水、测压管中的地下水以及流经OWS和MWS流域的溪流进行了采样。相对于两个流域中的其他地下水采样地点，OWS流动路径内和溪流附近的地下水中大肠杆菌浓度和电导率升高。OWS流域的地下水排放可能是溪流中大肠杆菌的一个来源，因为河岸处和溪流中的地下水中大肠杆菌浓度相似。在每个采样日期，OWS流域的溪流大肠杆菌浓度相对于MWS流域更高。通过确保OWS的安装和运行，以保持与水资源足够的间隔距离，可以改善水质。
