Hill Dagne D, Owens William E, Tchounwou Paul B
Department of Biological Sciences, Grambling State University, P.O. Box 887, Grambling, Louisiana , USA.
Int J Environ Res Public Health. 2006 Mar;3(1):114-7. doi: 10.3390/ijerph2006030013.
Fecal coliform bacteria are the most common pollutant in rivers and streams. In Louisiana, it has been reported that 37% of surveyed river miles, 31% of lakes, and 23% of estuarine water had some level of contamination. The objective of this research was to assess the effect of surface runoff amounts and rainfall amount parameters on fecal coliform bacterial densities in Bayou Dorcheat in Louisiana. Bayou Dorcheat has been designated by the Louisiana Department of Environmental Quality as a waterway that has uses such as primary contact recreation, secondary contact recreation, propagation of fish and wildlife, agriculture and as being an outstanding natural resource water. Samples from Bayou Dorcheat were collected monthly and analyzed for the presence of fecal coliforms. Fecal coliforms isolated from these samples were identified to the species level. The analysis of the bacterial levels was performed following standard test protocols as described in Standard Methods for the Examination of Water and Wastewater. Information regarding the rainfall amounts and surface runoff amounts for the selected years was retrieved from the Louisiana Office of State Climatology. It was found that a significant increase in the fecal coliform numbers may be associated with average rainfall amounts. Possible sources of elevated coliform counts could include sewage discharges from municipal treatment plants and septic tanks, storm water overflows, and runoff from pastures and range lands. It can be concluded that nonpoint source pollution that is carried by surface runoff has a significant effect on bacterial levels in water resources.
粪大肠菌群是河流和溪流中最常见的污染物。在路易斯安那州，据报道，受调查的河流里程中有37%、湖泊中有31%以及河口水中有23%受到了一定程度的污染。本研究的目的是评估地表径流量和降雨量参数对路易斯安那州多尔谢特河湾粪大肠菌群密度的影响。多尔谢特河湾已被路易斯安那州环境质量部指定为一条具有多种用途的水道，如一级接触式娱乐、二级接触式娱乐、鱼类和野生动物繁殖、农业以及作为一种杰出的自然资源水。每月从多尔谢特河湾采集样本，并分析其中粪大肠菌群的存在情况。从这些样本中分离出的粪大肠菌群被鉴定到种水平。细菌水平的分析按照《水和废水检验标准方法》中所述的标准测试方案进行。从路易斯安那州气候学办公室获取了所选年份的降雨量和地表径流量信息。研究发现，粪大肠菌群数量的显著增加可能与平均降雨量有关。大肠菌群数量升高的可能来源包括城市污水处理厂和化粪池的污水排放、雨水溢流以及牧场和放牧地的径流。可以得出结论，地表径流携带的非点源污染对水资源中的细菌水平有显著影响。
